Academic literature on the topic 'Two - three and four layers models'
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Journal articles on the topic "Two - three and four layers models"
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Rowe, Avery. "Effect of drainage layers on water retention of potting media in containers." PLOS ONE 20, no. 2 (2025): e0318716. https://doi.org/10.1371/journal.pone.0318716.
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Excess water retention in the potting medium can be a significant problem for plants grown in containers due to the volume of saturated medium which forms above the drainage hole. Adding a layer of coarse material like gravel or sand at the bottom is a common practise among gardeners with the aim of improving drainage, but some researchers have argued that such layers will raise the saturated area and in fact increase water retention. Two different depths and four different materials of drainage layer were tested with three different potting media to determine the water retention in the container after saturating and draining freely. For loamless organic media, almost all types of drainage layer reduced overall water retention in the container compared to controls. For loam-based media, most drainage layers had no effect on the overall water retention. Two simple models were also used to estimate the water retention in the media alone, excluding the drainage layer itself. All drainage layers reduced water retention of loamless organic media, according to both models. There was disagreement between the two models applied to loam-based media, and further study is required to determine the most accurate. Both models showed that some drainage layers with smaller particle sizes reduced water retention in loam-based media, but disagreed on the effect of drainage layers with larger particle sizes. Overall, any drainage layer was likely to reduce water retention of any medium, and almost never increased it. Thicker drainage layers were more effective than thinner layers, with the most effective substrate depending on the potting media used. A 60 mm layer of coarse sand was the most universally-effective drainage layer with all potting media tested.
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Alhassan, Seiba, Gaddafi Abdul-Salaam, Michael Asante, Yaw Missah, and Ernest Ganaa. "Analyzing Autoencoder-Based Intrusion Detection System Performance." Journal of Information Security and Cybercrimes Research 6, no. 2 (2023): 105–15. http://dx.doi.org/10.26735/ylxb6430.
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The rise in cyberattacks targeting critical network infrastructure has spurred an increased emphasis on the development of robust cybersecurity measures. In this context, there is a growing exploration of effective Intrusion Detection Systems (IDS) that leverage Machine Learning (ML) and Deep Learning (DL), with a particular emphasis on autoencoders. Recognizing the pressing need to mitigate cyber threats, our study underscores the crucial importance of advancing these methodologies. Our study aims to identify the optimal architecture for an Intrusion Detection System (IDS) based on autoencoders, with a specific focus on configuring the number of hidden layers. To achieve this objective, we designed four distinct sub-models, each featuring a different number of hidden layers: Test 1 (one hidden layer), Test 2 (two hidden layers), Test 3 (three hidden layers), and Test 4 (four hidden layers).We subjected our models to rigorous training and testing, maintaining consistent neuron counts of 30 and 60. The outcomes of our experimental study reveal that the model with a single hidden layer consistently outperformed its counterparts, achieving an accuracy of 95.11% for NSL-KDD and an impressive 98.6% for CIC-IDS2017. The findings of our study indicate that our proposed system is viable for implementation on critical network infrastructure as a proactive measure against cyber-attacks.
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Qdroo, Awf, and Muhammet Baykara. "A New Approach to Detect Fake News Related to Covid-19 Pandemic Using Deep Neural Network." Journal of Applied Science and Technology Trends 3, no. 02 (2022): 20–27. http://dx.doi.org/10.38094/jastt302124.
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The fake news that accompanied the COVID-19 pandemic on social media platforms negatively affected people and led to a state of panic and fear of the unknown. This study aims to build a model for classifying textual news for four datasets related to COVID-19, binary classification (fake and real) with high performance. Two hybrid deep learning models were built. The first model consists of three layers of a one-dimension convolutional neural network (1D-CNN), followed by two layers of a long-short-term memory neural network (LSTM). The second model consists of three layers of a 1D-CNN followed by two layers of a bidirectional LSTM neural network (BiLSTM). Finally, the results obtained using hybrid models were compared with the results obtained by applying three machine learning classifiers (naïve Bayes, logistic regression, and k-nearest neighbor) on the same data sets. This study achieved promising results with an accuracy of (96.98%, 94.52%, 99.60%, and 99.90%) for the first model with all data sets and (97.15%, 95.32%, 99.40%, and 99.82%) for the second model with the same four data sets.
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Schubert, Wayne, Richard Taft, and Christopher Slocum. "A Simple Family of Tropical Cyclone Models." Meteorology 2, no. 2 (2023): 149–70. http://dx.doi.org/10.3390/meteorology2020011.
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This review discusses a simple family of models capable of simulating tropical cyclone life cycles, including intensification, the formation of the axisymmetric version of boundary layer shocks, and the development of an eyewall. Four models are discussed, all of which are axisymmetric, f-plane, three-layer models. All four models have the same parameterizations of convective mass flux and air–sea interaction, but differ in their formulations of the radial and tangential equations of motion, i.e., they have different dry dynamical cores. The most complete model is the primitive equation (PE) model, which uses the unapproximated momentum equations for each of the three layers. The simplest is the gradient balanced (GB) model, which replaces the three radial momentum equations with gradient balance relations and replaces the boundary layer tangential wind equation with a diagnostic equation that is essentially a high Rossby number version of the local Ekman balance. Numerical integrations of the boundary layer equations confirm that the PE model can produce boundary layer shocks, while the GB model cannot. To better understand these differences in GB and PE dynamics, we also consider two hybrid balanced models (HB1 and HB2), which differ from GB only in their treatment of the boundary layer momentum equations. Because their boundary layer dynamics is more accurate than GB, both HB1 and HB2 can produce results more similar to the PE model, if they are solved in an appropriate manner.
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Tsepav, Matthew Tersoo, Azeh Yakubu, Kumar Niranjan, et al. "Geophysical Characterisation of Native Clay Deposits in Some Parts of Niger State, Nigeria." Journal of Physics: Theories and Applications 6, no. 1 (2022): 43. http://dx.doi.org/10.20961/jphystheor-appl.v6i1.56457.
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<p class="Abstract">Clay minerals are among the world’s most important and useful industrial minerals. Conductance, transmissivity and corrosity are some physical parameters for determining quality clay. Four (4) clay deposit sites in Kaffin-Koro, Dutse, Dogon-Ruwa and Kushikoko were investigated to evaluate corrosivity, the longitudinal conductance and transmissivity to determine the clay quality. Electrical resistivity method employing Schlumberger electrode array was used to determine the thicknesses and depths of the subsurface strata while Interpex 1xD software was used to interpret the data. Three (3) to four (4) layer earth models were delineated. Kaffin-Koro and Dutse showed three layer models while Dogon-Ruwa and Kushikoko revealed four layers. Moderate clay content was found in Kaffin-Koro in the second layer with longitudinal conductance value of 0.4780 siemens and thickness 0.770m at depth of 1.17m Dogon-Ruwa also had moderate clay content in the third layer with conductance value of 0.237 siemens, depth of 2.43m and thickness 1.76m. Kushikoko had low clay deposit in the second layer with conductance 0.1810 siemens and thickness 2.73 m at 4.37 m while the clay deposit in Dutse appeared to be generally poor as the longitudinal conductance values of the top two layers were less than 0.1 siemens.</p>
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Deokar, A. H., and A.A. Korake. "Experimental Investigation of Ferrocement Slab Panels Using Square Metal Mesh." Journal of Structural Engineering, its Applications and Analysis 7, no. 3 (2024): 7–12. https://doi.org/10.5281/zenodo.13770899.
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<em>The ongoing assessment depicts the outcomes of testing level ferrocement sheets upheld with different quantities of wire network layer and assortment in board thickness. The essential objective of these exploratory tests is to consider the effect of using different amounts of wire network Layers and thickness minor takeoff from the flexural strength of stage ferrocement discussions and to concentrate on the impact of fluctuating the amount of twine local area layers on the malleability and a conclusive force of this type of Ferrocement structure. In this assessment, all of the models were parceled into four social events to explore the strength and lead of ferrocement level sheets presented to two-point stacking. 24 ferrocement added substances have been built and endeavored. 24 ferrocement components were built and tried. The pre-owned number of wire network layers is single, two, three and four layers; additionally, thicknesses of boards are 30mm and 40mm.</em>
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Hekal, Ghada Mousa, Ayman Magdy Moawad Elshaboury, and Yousry B. I. Shaheen. "The impact of openings on ferrocement I-beams: a study on metallic and non-metallic mesh reinforcement." Challenge Journal of Concrete Research Letters 15, no. 2 (2024): 30. http://dx.doi.org/10.20528/cjcrl.2024.02.001.
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The primary objective of this investigation is to assess the influence of openings on the structural performance of ferrocement I-beams, incorporating diverse metallic and non-metallic mesh reinforcements. Sixteen beams underwent testing utilizing a four-point loading system until failure, categorized into four groups based on the type of mesh reinforcement. Each group comprised a control I-beam without openings and three additional beams featuring one, two, and three openings, respectively. To ensure consistent reinforcement weight, the four groups were reinforced with three layers of welded steel meshes, two layers of expanded metal meshes, two layers of Tensar meshes, and eight layers of Gavazzi meshes. Comparative analysis of the experimental outcomes was conducted with finite element models utilizing Abaqus. Therefore, there was good agreement between the experimental and numerical results. The findings showed that beams with no openings, one, and two openings reinforced with Gavazzi meshes had the highest ultimate load compared to other tested beams, while beams with three openings, those reinforced with expanded metal meshes had the greatest ultimate loads. Placing three openings in beams, with dimensions of 100×50 mm (two of these openings are approximately 10 cm apart from each edge while the third opening is located at mid-span), reduced the load-to-weight ratio by about 20.7%, 12.9%, 8.2%, and 23.8% for welded beams, expanded beams, Tensar beams, and Gavazzi beams, respectively, compared to the beams with no openings.
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Baines, Peter G., and Fiona Guest. "The nature of upstream blocking in uniformly stratified flow over long obstacles." Journal of Fluid Mechanics 188 (March 1988): 23–45. http://dx.doi.org/10.1017/s002211208800062x.
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The general method described in Baines 1988 has been applied to stratified flows of finite depth over long obstacles where the flow initially has uniform horizontal velocity. The fluid consists of a finite number of homogeneous layers of equal thickness and with equal density increments. This represents the state of continuous stratification with constant density gradient as closely as possible, for a given number of layers. Two-, three-, four- and sixty-four-layered models are studied in detail. The results are expressed in terms of the initial Froude number F0 (F0 = U/ĉ1 where U is the fluid speed and ĉ1 is the speed of the fastest long internal wave mode in the fluid at rest) and the obstacle height. In general, introduction of an obstacle into the flow causes disturbances to propagate upstream (columnar disturbance modes) which alter the velocity and density profiles there. These may accumulate to cause upstream blocking of some of the fluid layers if F0 is sufficiently small. As the number of fluid layers increases, so does the range of F0 for which this upstream blocked flow occurs. There are no upstream disturbances for F0 > 1, and for F0 < 1 the upstream disturbances are of the rarefaction type if upstream blocking does not occur. The results for three and four layers show how several coexisting modes may interact to affect the upstream profiles. The results for sixty-four-layers provide theoretical support for the observational criterion (Baines 1979b) that blocking in initially uniformly stratified flow occurs when Nhm/U > 2 (N is the Brunt—Väisälä frequency and hm the obstacle height), provided that more than two modes are present. In some situations, layered models are found to be inadequate as a representation of continuous stratification when one or more layers thicken to the extent that their discreteness is significant.
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Lawrence, E., E. J. Garba, Y. M. Malgwi, and M. A. Hambali. "An Application of Artificial Neural Network for Wind Speeds and Directions Forecasts in Airports." European Journal of Electrical Engineering and Computer Science 6, no. 1 (2022): 53–59. http://dx.doi.org/10.24018/ejece.2022.6.1.407.
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Wind speed patterns are highly dynamic and non-linear and thus cannot be accurately forecasted using conventional linear regression models. In this work, Artificial Neural Network (ANN) technique was applied to forecast wind speeds and directions in airports. Monthly data of maximum temperature, minimum temperature, wind speed, wind direction, relative humidity and wind run for Yola International Airport were collected from 1995 to 2021 from Nigerian Meteorological Agency (NIMET) Abuja-Nigeria. Six Neural Network models were built. ANN with no hidden layers, ANN model with one hidden layer and two dropout layers, ANN model with four hidden layers and three dropout layers, ANN model with eight hidden layers, ANN model with nine hidden layers and finally, ANN model with ten hidden layers. Back Propagation training algorithm was implemented using the PYTHON toolbox. Each of the models was trained using the training dataset and validated using the validation dataset. To test the forecasting ability of each of the models we tested it using unknown data that is the test dataset. The results from each of the models were organized and assessed in terms of the magnitude of the statistical error between the measured result and the real data. This was achieved by measuring the average of the Mean Square Errors (MSE) and Mean Absolute Error (MAE) for each of the models used for forecasting both wind speeds and directions. The results show that Multilayer perceptron with ten hidden layers with (MSE) = 0.92 and (MAE) = 0.73 emerged as the most preferred model for wind speeds forecast while the multilayer perceptron with four hidden layers with (MSE) = 1,858 and (MAE) = 35 emerged the most preferred model for wind directions forecast. Future research can be carried out to improve the accuracy of the model for wind direction forecasts.
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Mehmood, Maryam, Farhan Hussain, Ahsan Shahzad, and Nouman Ali. "Classification of Remote Sensing Datasets with Different Deep Learning Architectures." Earth Sciences Research Journal 28, no. 4 (2025): 409–19. https://doi.org/10.15446/esrj.v28n4.113518.
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Remote sensing image classification has great advantages in the areas of environmental monitoring, urban planning, disaster management and many others. Unmanned Aerial Vehicles (UAVs) have revolutionized remote sensing by providing high-resolution imagery. In this context, effective image classification is crucial for extracting meaningful information from UAV-captured images. This study presents a comparison of different deep learning-based approach for supervised image classification of UAV images. We have experimented on four different CNN models like VGG 16, Alex net, Resnet50 and a deep neural network Efficient-Net-B0 on different remote sensing datasets; AID and AIDER. Multiple combinations were tried to find out which model performs better on which type of datasets. We have used pre-trained initial layers of four CNN models (AlexNet, VGG 16, Resnet50 and Efficient-Net-Bo) then last three layers of each of the selected models are removed and new layers have been added with better tuned parameters. Two different schemes were analyzed. In Scheme-1 the original AlexNet, VGG 16, Resnet50 and Efficient-Net-B0 were experimented without changing and tuning their number of parameters, while in Scheme-2 transfer learning was applied on the pre-trained models and after removing last three layers new layers were added with better tuned hyper-parameters. The evaluation of above schemes was ensured through comprehensive metrics across diverse land cover classes, four different performance evaluation matrices namely; F1 score, precision, accuracy and recall. The main focus of this research is towards transfer learning and adding new layers into pre-trained models to get better classification accuracy.
Dissertations / Theses on the topic "Two - three and four layers models"
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Javerzat, Nina. "New conformal bootstrap solutions and percolation models on the torus Two-point connectivity of two- dimensional critical Q-Potts random clusters on the torus Three- and four-point connectivities of two-dimensional critical Q-Potts random clusters on the torus Topological effects and conformal invariance in long-range correlated random surfaces Notes on the solutions of Zamolodchikov- type recursion relations in Virasoro minimal models." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP062.
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Les propriétés géométriques des phénomènes critiques ont généré un intérêt croissant en physique théorique ainsi qu'en mathématiques au cours des trente dernières années. Les systèmes de percolation sont l'exemple par excellence de tels phénomènes géométriques, où la transition de phase est caractérisée par le comportement de degrés de liberté non-locaux, les amas de percolation. Au point critique, ces amas sont des exemples d'objets aléatoires dont la mesure est invariante conforme, c'est à dire invariante sous tout changement d'échelle local. Nous ne savons en général pas caractériser complètement ces amas, ni même pour le modèle le plus simple de la percolation pure. En deux dimensions, la présence de la symétrie conforme a des conséquences particulièrement importantes. Dans cette thèse nous examinons les implications de cette symétrie sur les propriétés universelles des systèmes critiques bidimensionnels, en utilisant une approche dite de bootstrap conforme. La première partie détaille les implications générales de l'invariance conforme, en examinant ses conséquences sur les fonctions de corrélation. Sont considérés en particulier les effets induits par une topologie de tore, ce qui est appliqué dans la deuxième partie de la thèse à l'étude de modèle statistiques particuliers. Nous discutons également les propriétés analytiques des fonctions de corrélation et présentons des résultats sur des questions techniques liées à l'implémentation de méthodes numériques de bootsrap conforme en deux dimensions. La seconde partie est dédiée à l'étude de deux familles particulières de modèles critiques de percolation avec des corrélations de longue portée : le modèle d'amas aléatoires de Potts à Ǫ états, et un modèle de percolation de surfaces aléatoires. Nous explorons les propriétés percolatoires de ces modèles en étudiant les propriétés de connectivité des amas, c'est à dire les probabilités que des points appartiennent au même amas. Nous avons réalisé que les connectivités sur le tore représentent des observables très intéressantes. En les décrivant comme fonction de corrélation de champs quantiques dans une théorie des champs conforme, nous obtenons de nouveaux résultats sur les classes d'universalité de ces modèles<br>The geometric properties of critical phenomena have generated an increasing interest in theoretical physics and mathematics over the last thirty years. Percolation-type systems are a paradigm of such geometric phenomena, their phase transition being characterised by the behaviour of non-local degrees of freedom: the percolation clusters. At criticality, such clusters are examples of random objects with a conformally invariant measure, namely invariant under all local rescalings. Even in the simplest percolation model --pure percolation, we do not know how to fully characterise these clusters. In two dimensions, the presence of conformal symmetry has especially important implications. In this thesis we investigate the consequences of this symmetry on the universal properties of two-dimensional critical statistical models, by using a conformal bootstrap approach. The first part details the general implications of conformal invariance, by examining its consequences on correlation functions. Are addressed in particular the effects induced by the torus topology, applied in the second part to the study of specific statistical models. We also examine the analytic properties of correlation functions and present results on technical questions related to the implementation of numerical conformal bootstrap methods in two dimensions. The second part is devoted to the study of two specific families of critical long-range correlated percolation models: the random cluster Q-state Potts model and the percolation of random surfaces. We investigate the percolative properties of these models by studying the clusters connectivity properties, namely the probability that points belong to the same cluster. We find that the connectivities on a torus represent particularly interesting observables. By describing them as correlation functions of quantum fields in a conformal field theory, we obtain new results on the universality classes of these models
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Onyeako, Isidore. "Resolution-aware Slicing of CAD Data for 3D Printing." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34303.
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3D printing applications have achieved increased success as an additive manufacturing (AM) process. Micro-structure of mechanical/biological materials present design challenges owing to the resolution of 3D printers and material properties/composition. Biological materials are complex in structure and composition. Efforts have been made by 3D printer manufacturers to provide materials with varying physical, mechanical and chemical properties, to handle simple to complex applications. As 3D printing is finding more medical applications, we expect future uses in areas such as hip replacement - where smoothness of the femoral head is important to reduce friction that can cause a lot of pain to a patient. The issue of print resolution plays a vital role due to staircase effect. In some practical applications where 3D printing is intended to produce replacement parts with joints with movable parts, low resolution printing results in fused joints when the joint clearance is intended to be very small. Various 3D printers are capable of print resolutions of up to 600dpi (dots per inch) as quoted in their datasheets. Although the above quoted level of detail can satisfy the micro-structure needs of a large set of biological/mechanical models under investigation, it is important to include the ability of a 3D slicing application to check that the printer can properly produce the feature with the smallest detail in a model. A way to perform this check would be the physical measurement of printed parts and comparison to expected results. Our work includes a method for using ray casting to detect features in the 3D CAD models whose sizes are below the minimum allowed by the printer resolution. The resolution validation method is tested using a few simple and complex 3D models. Our proposed method serves two purposes: (a) to assist CAD model designers in developing models whose printability is assured. This is achieved by warning or preventing the designer when they are about to perform shape operations that will lead to regions/features with sizes lower than that of the printer resolution; (b) to validate slicing outputs before generation of G-Codes to identify regions/features with sizes lower than the printer resolution.
Books on the topic "Two - three and four layers models"
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Bell, J. H. Contraction design for small low-speed wind tunnels. National Aeronautics and Space Administration, 1988.
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Jaworski, Barbara, Josef Rebenda, Reinhard Hochmuth, et al. Inquiry in University Mathematics Teaching and Learning. Masaryk University Press, 2021. http://dx.doi.org/10.5817/cz.muni.m210-9983-2021.
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The book presents developmental outcomes from an EU Erasmus+ project involving eight partner universities in seven countries in Europe. Its focus is the development of mathematics teaching and learning at university level to enhance the learning of mathematics by university students. Its theoretical focus is inquiry-based teaching and learning. It bases all activity on a three-layer model of inquiry: (1) Inquiry in mathematics and in the learning of mathematics in lecture, tutorial, seminar or workshop, involving students and teachers; (2) Inquiry in mathematics teaching involving teachers exploring and developing their own practices in teaching mathematics; (3) Inquiry as a research process, analysing data from layers (1) and (2) to advance knowledge inthe field. As required by the Erasmus+ programme, it defines Intellectual Outputs (IOs) that will develop in the project. PLATINUM has six IOs: The Inquiry-based developmental model; Inquiry communities in mathematics learning and teaching; Design of mathematics tasks and teaching units; Inquiry-based professional development activity; Modelling as an inquiry process; Evalutation of inquiry activity with students. The project has developed Inquiry Communities, in each of the partner groups, in which mathematicians and educators work together in supportive collegial ways to promote inquiry processes in mathematics learning and teaching. Through involving students in inquiry activities, PLATINUM aims to encourage students` own in-depth engagement with mathematics, so that they develop conceptual understandings which go beyond memorisation and the use of procedures. Indeed the eight partners together have formed an inquiry community, working together to achieve PLATINUM goals within the specific environments of their own institutions and cultures. Together we learn from what we are able to achieve with respect to both common goals and diverse environments, bringing a richness of experience and learning to this important area of education. Inquiry communities enable participants to address the tensions and issues that emerge in developmental processes and to recognise the critical nature of the developmental process. Through engaging in inquiry-based development, partners are enabled and motivated to design activities for their peers, and for newcomers to university teaching of mathematics, to encourage their participation in new forms of teaching, design of teaching, and activities for students. Such professional development design is an important outcome of PLATINUM. One important area of inquiry-based activity is that of “modelling” in mathematics. Partners have worked together across the project to investigate the nature of modelling activities and their use with students. Overall, the project evaluates its activity in these various parts to gain insights to the sucess of inquiry based teaching, learning and development as well as the issues and tensions that are faced in putting into practice its aims and goals.
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Wijnhoven, Martijn A. European Mail Armour. Amsterdam University Press, 2021. http://dx.doi.org/10.5117/9789463721264.
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Mail armour (commonly mislabelled 'chainmail') was used for more than two millennia on the battlefield. After its invention in the Iron Age, mail rapidly spread all over Europe and beyond. The Roman army, keen on new military technology, soon adopted mail armour and used it successfully for centuries. Its history did not stop there and mail played a vital role in warfare during the Middle Ages up to the Early Modern Period. Given its long history, one would think mail is a well-documented material, but that is not the case. For the first time, this books lays a solid foundation for the understanding of mail armour and its context through time. It applies a long-term multi-dimensional approach to extract a wealth of as yet untapped information from archaeological, iconographic and written sources. This is complemented with technical insights on the mail maker’s chaîne opératoire.
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Chemin, Jean-Yves, Benoit Desjardins, Isabelle Gallagher, and Emmanuel Grenier. Mathematical Geophysics. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780198571339.001.0001.
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Aimed at graduate students, researchers and academics in mathematics, engineering, oceanography, meteorology, and mechanics, this text provides a detailed introduction to the physical theory of rotating fluids, a significant part of geophysical fluid dynamics. The text is divided into four parts, with the first part providing the physical background of the geophysical models to be analyzed. Part two is devoted to a self contained proof of the existence of weak (or strong) solutions to the imcompressible Navier-Stokes equations. Part three deals with the rapidly rotating Navier-Stokes equations, first in the whole space, where dispersion effects are considered. The case where the domain has periodic boundary conditions is then analyzed, and finally rotating Navier-Stokes equations between two plates are studied, both in the case of periodic horizontal coordinated and those in R2. In Part IV, the stability of Ekman boundary layers and boundary layer effects in magnetohydrodynamics and quasigeostrophic equations are discussed. The boundary layers which appear near vertical walls are presented and formally linked with the classical Prandlt equations. Finally spherical layers are introduced, whose study is completely open.
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Roth, Daniel. Third-Party Peacemakers in Judaism. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780197566770.001.0001.
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Third-Party Peacemakers in Judaism presents thirty-six case studies featuring third-party peacemakers found within Jewish rabbinic literature. Each case study is explored through three layers of analysis: text, theory, and practice. The textual analysis consists of close literary and historical readings of legends and historical accounts as found within classical, medieval, and early-modern rabbinic literature, many of which are critically analyzed here for the first time. The theoretical analysis consists of analyzing the models of third-party peacemaking embedded within the various cases studies by comparing them with other cultural and religious models of third-party peacemaking and conflict resolution, in particular the Arab-Islamic sulha and contemporary Interactive Problem-Solving Workshops. The final layer of analysis, based upon the author’s personal experiences in years of doing conflict resolution education, trainings, and actual third-party religious peacemaking in the context of the Middle East, relates to the potential practical implications of these case studies to serve as indigenous models and sources of inspiration for third-party mediation and peacemaking in both interpersonal and intergroup conflicts today.
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Stańczykiewicz, Arkadiusz. Prawdopodobieństwo wystąpienia szkód w odnowieniach podokapowych wskutek pozyskiwania drewna oraz model ich szacowania. Publishing House of the University of Agriculture in Krakow, 2018. http://dx.doi.org/10.15576/978-83-66602-34-2.
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An analysis of the existing literature on the issue of damage to regeneration caused by timber harvesting, revealed that a great majority of results reported in those publications was obtained through laborious and time-consuming field research conducted in two stages. Field research methods for gathering data, employed by various authors, differed in terms of the manner of establishing trial plots, the accuracy of counting and evaluating the number of saplings growing on the investigated sites, classification systems used for distinguishing particular groups of regeneration based on quantitative (diameter at breast height, tree height) and qualitative features (biosocial position within the certain layer and the entire stand), classification systems used for identifying types of damage caused by cutting and felling, as well as transporting operations, and finally the duration of observation intervals and time spent on gathering data on the response of damaged saplings from both, the individual and collective perspectives. Obviously, the most reliable manner of gathering such data would be to count all damaged elements of the environment being a subject of interest of particular investigators at the certain point of time. However, due to time and work consumption of this approach, which is besides very costly, any research should be designed in such a manner as to reduce the above-mentioned factors. This paper aimed to (1) analyse the probability of occurrence of damage to regeneration depending on the form of timber assortments dragged from the felling site to the skidding routes, and timber harvesting technology employed in logging works, and (2) identify a method ensuring that gathered data is sufficient for performing reliable evaluation of share of damage to regeneration at acceptable accuracy level, without necessity to establish trial plots before commencing harvesting works. The scope of these studies enclosed a comparison between two motor-manual methods of timber harvesting in thinned stands, with dragging of timber in the first stage of skidding from the stand to landings. According to one of these methods, a classical one, operations of felling and delimbing of trees were carried out by sawmen at the felling site. Timber obtained using different methods was skidded by carters and horses, and operators of a light-duty cable winch, driven by the chainsaw’s engine, as well as operators of cable winches combined with farm tractors. In the latter, alternative method, sawmen performed only cutting and felling of trees. Delimbing and cross-cutting of trunks, dragged from the felling sites, was carried out by operators of processors combined with farm tractors, worked on skidding routes. The research was conducted in the years 2002–2010 in stands within the age classes II–IV mostly, located in the territories of Regional Directorates of State Forests in Krakow and Katowice, and in the Forest Experimental Unit in Krynica-Zdrój. In the course of a preliminary stage of investigations 102 trial plots were established in stands within early and late tinning treatments. As a result of the field research carried out in two stages, more than 3.25 thsd. circular sites were established and marked, on the surface of which over 25 thsd. saplings constituting the regeneration layer were inventoried. Based on the results of investigations and analyses it was revealed that regardless of the category of thinning treatment, the highest probability of occurrence of destroying P(ZN) to regeneration (0.24–0.44) should be expected when the first stage of timber skidding is performed using cable winches. Slightly lower values of probability (0.17–0.33) should be expected in stands where timber is skidded by horses, while in respect to processor-based skidding technology the probability of destroying occurrence oscillates between 0.12 and 0.27, depending on the particular layer of regeneration. P(ZN) values, very close to those of skidding technology engaging processors, were recorded for skidding performed using the light-duty cable winch driven by the chainsaw’s engine (0.16–0.27). The highest probability of damage P(USZK) to regeneration (0.16–0.31) can be expected when processors are used in the first stage of timber skidding. Slightly lower values of probability (0.14–0.23) were obtained when skidding was performed with the use of cable winches, whereas engaging horses for hauling of trunks results in probability of damage occnrrence oscillating between 0.05–0.20, depending on the particular layer of regeneration. With regard to the probability of occurrence of both, destroying and damage P(ZNUSZK) to regeneration (0.33–0.54), the highest values can be expected when cable winches are engaged in the first stage of skidding. Little lower (0.30–0.43) was the probability of their occurrence if processor-based technology of skidding was employed, while in respect to horse skidding these values oscillated between 0.27–0.41, depending on the layer of regeneration. The lowest values of probability of occurrence of damage P(USZK), and destroying and damage treated collectively P(ZNUSZK), within all layers of regeneration, were recorded in stands where thinning treatments were performed using the light-duty cable winch driven by the chainsaw’s engine. The models evaluated and respective equations, developed based on those models, for evaluating the number of destroyed saplings ZNha (tab. 40, 42, 44, 46, 48) could be used for determining the share of damage expressed as a percentage, upon conducting only one field research at the investigated felling sites, once the timber harvesting and skidding would have been completed. As revealed by the results of analyses, evaluation of statistically significant regression models was possible for all layers of regeneration (tab. 39, 41, 43, 45, 47). Nevertheless, the smallest part of these models that could be considered positively verified, were those for the natural young regeneration, although almost a half of them revealed to be significant. Within the medium-sized regeneration over three-fourths of all models could be considered positively verified, four of which explained more than 50% of variability. Within the high-sized regeneration almost two-thirds of evaluated regression models were statistically significant, five of which were verified positively, moreover, one of them explained more than 50% of variability. The most promising results were those obtained for the advance growth. Nearly 90% of the evaluated models revealed to be statistically significant, ten of which could be considered positively verified. Furthermore, four statistically significant models explained over 50% of general variability. With regard to the entire regeneration more than 80% of evaluated models were statistically significant. However, due to insignificant coefficients of regression, eight of them could be considered positively verified. At this point it should be stressed that in respect to logging technology employing the light-duty cable winch FKS it was impossible to evaluate statistically significant models of regression. Whereas, in the case of processor-based logging technology, firstly regarding the advance growth, and then the entire regeneration, all of the evaluated statistically significant models could be considered positively verified, in terms of both, all of the stands, and particular categories of thinning treatments individually. This latter case also revealed the highest degree of matching of evaluated models (R2 popr 0.73–0.76 for advance growth and 0.78–0.94 for the entire regeneration). A significant impact of the kind of form of hauled timber on the probability of damage occurrence P(USZK), mainly in early thinning treatments, could have been reflected in the results obtained for all stands (early and late thinning treated collectively). Moreover, due to an insignificant impact of the form of hauled timber and logging technology employed, on the probability of occurrence of damage in late thinned stands, and a significant impact of the above-mentioned variables on early thinned stands, it should be assumed that for performing an evaluation of destroying and damage caused by timber harvesting the both thinning treatment categories should be analysed separately. Furthermore, when evaluating the probability of occurrence of destroying and damage caused by timber harvesting, the layers of natural young regeneration and advance growth should be analysed separately. As proved by the results presented in this paper, varying values of probability computed for each of the layers of regeneration seem to indicate that when investigating damage to regeneration caused by timber harvesting, it would be reasonable and recommended to perform a separate analysis of damage to the highest saplings as well, namely individuals with diameter at breast height close to 7 cm. In respect to studies on damage to regeneration caused by logging technologies mentioned above, the evaluation of number of destroyed saplings within the advance growth can be carried out using the proportions of damaged and undamaged saplings per 1 ha of the stand. The numbers evaluated in this manner can be used to calculate the damage share expressed in relative values (percentage of damaged saplings compared with the entire number of saplings before commencing the logging works). However, one should keep in mind that this is true only if the field research have been carried out based on the methodology described in this paper.
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Kriegel, Uriah. The Modes of Conscious Intentionality. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198791485.003.0004.
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Chap. 1 concerned Brentano’s theory of consciousness, and Chap. 2 his theory of intentionality, the mark of the conscious. This chapter lays the foundations for the rest of the book by discussing the three fundamental modes of conscious intentionality in Brentano’s theory of mind. This three-way distinction is crucial, as will later be seen, to Brentano’s metaphysics and value theory.
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Kirchin, Simon. Conceptual Relations. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198803430.003.0003.
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This chapter is designed to lay the foundations for the consideration of three anti-separationist strategies, in Chapters Four, Five, and Six. It lays out two models of how thin and thick concepts may relate to one another: the genus–species model and the determinable–determinate model. It argues that the genus–species model is simply separationism by another name. It argues that nonseparationists should not adopt either model because neither can accommodate ‘evaluative flexibility’, which is itself introduced and motivated. The chapter ends by suggesting a different model of conceptual relations that nonseparationists can adopt to understand the relation between thin and thick concepts.
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Carr, David M. The Formation of Genesis 1-11. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190062545.001.0001.
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There is general agreement that study of the formation of the Pentateuch is currently in disarray. This book turns to the Genesis Primeval History, Genesis 1–11, to offer models for the formation of Pentateuchal texts that might have traction within this fractious context. Building on two centuries of historical study of Genesis 1–11, this book provides new support for the older theory that the bulk of Genesis 1–11 was created out of a combination of two originally separate source strata: a Priestly source and an earlier non-Priestly source that was used to supplement the Priestly framework. Though this overall approach contradicts some recent attempts to replace such source models with theories of post-Priestly scribal expansion, the author of this volume does find evidence of multiple layers of scribal revision in the non-P and P sources: from the expansion of an early independent non-Priestly primeval history with a flood narrative and related materials through to a limited set of identifiable layers of Priestly material that culminate in the P-like redaction of the whole. Finally, the book synthesizes prior scholarship to show how both the P and non-Priestly strata of Genesis also emerged out of a complex interaction by Judean scribes with nonbiblical literary traditions, particularly with Mesopotamian textual traditions about primeval origins.
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Epstein, Charlotte. Birth of the State. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190917623.001.0001.
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This book uses the body to peel back the layers of time and taken-for-granted-ness upon the two defining political forms of modernity, the state and the subject of rights. It traces, under the lens of the body, how the state and the subject mutually constituted each other all the way down, by going all the way back, to their original crafting in the seventeenth century. It considers multiple sites of theory and practice and two revolutions. The first, scientific, threw humanity out of the centre of the universe, and transformed the very meanings of matter, space, and the body; while the second, legal and political, re-established humans as the centre-point of a framework of rights. The book analyses the fundamental rights to security, liberty, and property, respectively, as the initial knots where the state-subject relation was first sealed. It develops three arguments, that the body served to naturalise security, to individualise liberty, and to privatise property. Covering a wide range of materials—from early modern anatomy lesson paintings, to the Anglo-Scottish legal struggles of naturalisation, to the emergence of discrete practices of religious toleration in Central Europe—it shows both how the body has operated as history’s great naturaliser, and how it can be mobilised instead as a critical tool that lays bare the deeply racialised and gendered constructions that made both the state and the subject of rights. The book returns to the origins of constructivist and constitutive theorising to reclaim their radical and critical potential.
Book chapters on the topic "Two - three and four layers models"
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Poliakov, A. N. B., P. A. Cundall, Y. Y. Podladchikov, and V. A. Lyakhovsky. "An Explicit Inertial Method for the Simulation of Viscoelastic Flow: An Evaluation of Elastic Effects on Diapiric Flow in Two- and Three- Layers Models." In Flow and Creep in the Solar System: Observations, Modeling and Theory. Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8206-3_12.
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Mikriukov, Georgii, Gesina Schwalbe, Christian Hellert, and Korinna Bade. "Revealing Similar Semantics Inside CNNs: An Interpretable Concept-Based Comparison of Feature Spaces." In Communications in Computer and Information Science. Springer Nature Switzerland, 2025. https://doi.org/10.1007/978-3-031-74630-7_1.
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Abstract Safety-critical applications require transparency in artificial intelligence (AI) components, but widely used convolutional neural networks (CNNs) widely used for perception tasks lack inherent interpretability. Hence, insights into what CNNs have learned are primarily based on performance metrics, because these allow, e.g., for cross-architecture CNN comparison. However, these neglect how knowledge is stored inside. To tackle this yet unsolved problem, our work proposes two methods for estimating the layer-wise similarity between semantic information inside CNN latent spaces. These allow insights into both the flow and likeness of semantic information within CNN layers, and into the degree of their similarity between different network architectures. As a basis, we use two renowned explainable artificial intelligence (XAI) techniques, which are used to obtain concept activation vectors, i.e., global vector representations in the latent space. These are compared with respect to their activation on test inputs. When applied to three diverse object detectors and two datasets, our methods reveal that (1) similar semantic concepts are learned regardless of the CNN architecture, and (2) similar concepts emerge in similar relative layer depth, independent of the total number of layers. Finally, our approach poses a promising step towards semantic model comparability and comprehension of how different CNNs process semantic information.
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Huang, Yan, Zhipeng Cai, and Anu G. Bourgeois. "Privacy Protection for Context-Aware Services: A Two-Layer Three-Party Game Model." In Wireless Algorithms, Systems, and Applications. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-23597-0_10.
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Teshima, Yoshinori, Yohsuke Hosoya, Kazuma Sakai, et al. "Development of Tactile Globe by Additive Manufacturing." In Lecture Notes in Computer Science. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-58796-3_49.
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AbstractTo understand geographical positions, globes adapted for tactile learning is needed for people with visual impairments. Therefore, we created three-dimensional (3D) tactile models of the earth for the visually impaired, utilizing the exact topography data obtained by planetary explorations. Additively manufactured 3D models of the earth can impart an exact shape of relief on their spherical surfaces. In this study, we made improvements to existing models to satisfy the requirements of tactile learning. These improvements were the addition of the equator, prime meridian, and two poles to a basis model. Hence, eight types of model were proposed. The equator and the prime meridian were expressed by the belt on four models (i.e., B1, B2, B3, and B4). The height of their belt was pro-vided in four stages. The equator and the prime meridian were expressed by the gutter on four models (i.e., C1, C2, C3, and C4). The width of their gutter was provided in four stages. The north pole was expressed by a cone, while the south pole was expressed by a cylinder. The two poles have a common shape in all of the eight models. Evaluation experiments revealed that the Earth models developed in this study were useful for tactile learning of the visually impaired.
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Tsai, Li-Chen. "Decoding the unconscious for insight into free will and memory storage – A comparative analysis of the three-layer psychological structure and the two-layer body-mind memory model." In System Innovation for an Artificial Intelligence Era. CRC Press, 2024. http://dx.doi.org/10.1201/9781003514831-68.
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Corneli, Alessandra, Leonardo Binni, Berardo Naticchia, and Massimo Vaccarini. "Digital Twin Models Supporting Cognitive Buildings for Ambient Assisted Living." In The Urban Book Series. Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-29515-7_16.
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AbstractThe rapid and global aging of population is outlining the need for environments that can provide support for these individuals during their daily activities. The challenge of an aging society is being addressed through the incorporation of new technologies into the home environment, which is nothing less than Ambient Assisted Living (AAL). To date, some of the AAL solutions exploit AI models to recognize the elderly’s behaviors through data collected by sensors. In recent times, Digital Twins (DTs) at building level have begun to appear on the construction domain. These are still under development but through the integration of users into assessments, they improve efficiency, prevention, and prediction of likely events through real-time AI computing. The integration of DT and AAL defines cognitive buildings which aim to learn at scale, reason with a purpose, and co-operate with users in a natural way. This research aims to develop DT models to achieve scenario awareness to provide support to elderly people living alone and suffering from cognitive disorders. The proposed multi-agent architecture is based on a five-layer system that autonomously develops high-level knowledge to detect anomalies in the home environment scenarios and therefore support the user. Bayesian networks (BNs) are exploited to perform high-level deductive reasoning on low-level multi-modal information, thus recognizing senseless or dangerous behaviors, environmental disruptions, changes in behavioral patterns, and serious medical events. Bi-directional user-system interaction provides user support by leveraging Speech-To-Text and Text-To-Speech AI agents. Three main functions were tested: real-time data integration, anomaly detection, and two-way interaction.
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Hanes, Chelene C., Mike Wotton, Douglas G. Woolford, et al. "Improved prediction of drought for wildland fire danger rating in Canada." In Advances in Forest Fire Research 2022. Imprensa da Universidade de Coimbra, 2022. http://dx.doi.org/10.14195/978-989-26-2298-9_40.
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Canadian fire management agencies track drought conditions using the Drought Code (DC). The DC is one of three fuel moisture codes in the Fire Weather Index System, which is part of the Canadian Forest Fire Danger Rating System. The DC represents the moisture of deep organic layers (15-18 cm nominal depth) and is used operationally to assess potential lightning ignition holdover, persistent deep smoldering, and mop-up problems. As the climate changes and drought conditions arise more frequently, our understanding of drought and how to measure it become more important. Determining what the DC means in areas without deep organic soils is a question commonly proposed by fire operations personnel. Recent studies have indicated that some more complex models (e.g. the Canadian Land Data Assimilation System – CaLDAS) may provide added intelligence about the fire environment and drought conditions, something that has not been explored in Canada. To shed light on these questions we carried out field studies in the provinces of Alberta and Ontario. Four field sites were included in our study, two in Alberta near Edson and Red Earth Creek, and two in Ontario near Dryden and Chapleau. At each of the seven plots within these four sites, we installed 8-12 water content reflectometry (WCR) probes at two different depths. The probes were installed from the surface through the organic layers, and in some cases, into the mineral soil. Overall, our results indicated that the simple DC model predicted the moisture content of the deeper organic layers (10-18 cm depths) well, even compared to the more complex CaLDAS model. The WCR probes at these depths, exhibited good agreement with how the DC model estimated moisture changes. The DC may therefore be representative of changes in moisture content in a wide range of depths and soil horizons. Issues with model inputs, particularly missed precipitation events and incorrect DC spring starting values, had a greater influence on DC model fit than other factors. Calibration and validation of the CaLDAS model to mineral soils may be the cause of its consistent under prediction of organic layer moisture.
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Gupta, Abhilasha, Krishna Joshi, and Umesh Diwedi. "Image and its Coordinates Detection in Convolution Neural Network Using YOLO Framework." In Artificial Intelligence and Communication Technologies, 2023rd ed. Soft Computing Research society, 2023. http://dx.doi.org/10.52458/978-81-955020-5-9-86.
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Computer vision is a field that deals with high level under- standing from digital Images. It provides new directions for making machines attentive and responsive to man. In this paper we are propos- ing an approach that is used for image detection. Face detection is a major problem in this area and many dataset are created for the pur- pose of computer vision. We have various deep learning models like convolutional neural network, recurrent neural network etc. But among all, deep convolutional neural networks are the best model for finding patterns from images. In the same direction we designed a model which receives its input from three fully connected layer that predict the coor- dinates and probability, and fully connected layer gets its input from Pooling layer that would scale back number of parameters when pic- tures are over large. To detect the image features and its coordinates we are using bounding boxes. Image detection is performing with the help of convolution neural network that is getting its input from three fully connected layers and fully connected layer is getting its input from Pooling layer. We used Relu layer to provide input to pooling layer. In this way images features are classified and the image is predicted on the basis of this model. So our output layer predicts both class proba- bility and coordinates of bounding boxes. The work is tested with the help of two experiment setup on two different machines. Results gave remarkable achievement and future directions.
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Wright, Sharon. "Re-theorising conditional welfare as gendered lived experience and street-level practice." In Women and Welfare Conditionality. Policy Press, 2023. http://dx.doi.org/10.1332/policypress/9781447347736.003.0002.
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This literature-based chapter offers a new feminist analysis of welfare conditionality that questions taken-for-granted ways of knowing about social security, benefit sanctions and support. It considers how academic conceptualisations of conditionality are implicitly gendered and highlights the ethics of care literature as an alternative way to understand interdependency and care of self and others. Insights from feminist interpretivism and the street-level bureaucracy literature reveal how women’s lives are mediated by welfare conditionality texts via front-line practices of profit-motivated service outsourcing and discretion. Smith’s approach is outlined to view social security in terms of textually mediated relations of ruling, highlighting the gendered hierarchy of ‘facts’, ‘boss texts’, ideology, the disjuncture between institutional categories and women’s lived experiences, and institutional circuits. A fresh model of UK welfare conditionality is presented, involving four textual layers: layer one consists of the domain assumptions and origin stories of policy texts; layer two is the legal and policy boss texts; layer three is the hidden institutional texts that preconfigure front-line practice; and layer four is comprised of the many policy instruments that operate at street-level.
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Goel, Amit, Amit Tiwary, and Heinz Schmidt. "Green ICT and Architectural Frameworks." In Green Technologies. IGI Global, 2011. http://dx.doi.org/10.4018/978-1-60960-472-1.ch207.
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Green ICT Practices fall in two different extremes of either only recommendations to reduce the resource usage such as electricity, or high level strategic management techniques such as Green Balanced Scorecard. The one extreme is very micro level operational approach and the other extreme is just paper strategies without a roadmap for total sustainability. This chapter proposes the enterprise architecture framework and mathematical model providing dynamic model for total sustainability. A brief description of currently popular Green ICT Metrics in practice is presented, together with a discussion of architectural frameworks providing three different architecture layers and a roadmap to achieve desirable “total sustainability indicator (TSI™) - a measurement framework based on mathematical models and game theory.
Conference papers on the topic "Two - three and four layers models"
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Vieira, João Marcos Bastos, and José Renato Mendes de Sousa. "Gas Diffusion in Flexible Pipes: A Comparison Between Two- and Three-Dimensional FE Models to Predict Annulus Composition." In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-78325.
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Abstract The Brazilian offshore oil and gas industry uses flexible pipes to transport water, oil, and/or gas. Currently, the high concentration of acid gases, such as carbon dioxide (CO2) and hydrogen sulfide (H2S), in Brazilian pre-salt wells has been introducing new challenges to these pipes. The acid gases may migrate from the bore to the annulus of these structures, forming a corrosive environment that can induce the steel armors’ failure by SCC (Stress Corrosion Cracking) or HIC (Hydrogen Induced Cracking). Hence, predicting the gas composition in the annulus is of fundamental importance to ensure the safe operation of flexible pipes. However, this prediction involves complex gas permeation analyses through the layers of these pipes. For instance, the permeation rate depends on temperature, gases partial pressures, and the free volume distribution. Therefore, new tools are required to understand better the fluid permeation between the flexible pipes’ layers. Therefore, this paper presents and compares two finite element (FE) models to predict the annulus composition of flexible pipes. Both models consider the temperature gradient effects on the layers’ material properties. On the one hand, the first approach deals with a two-dimensional model that considers helical layers as rings. So, the shielding effect is simplified. On the other, the second develops a complete three-dimensional model of the cross-section geometry. The results indicate that, while being faster, the two-dimensional approach shows higher concentration results than the three-dimensional approach. Furthermore, the difference between the two approaches suggests that the shielding provided by the helicoidal wires is relevant.
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Peng, Zhaopeng, Xiaoliang Fan, Yufan Chen, et al. "FedPFT: Federated Proxy Fine-Tuning of Foundation Models." In Thirty-Third International Joint Conference on Artificial Intelligence {IJCAI-24}. International Joint Conferences on Artificial Intelligence Organization, 2024. http://dx.doi.org/10.24963/ijcai.2024/531.
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Adapting Foundation Models (FMs) for down- stream tasks through Federated Learning (FL) emerges a promising strategy for protecting data privacy and valuable FMs. Existing methods fine- tune FM by allocating sub-FM to clients in FL, however, leading to suboptimal performance due to insufficient tuning and inevitable error accumula- tions of gradients. In this paper, we propose Feder- ated Proxy Fine-Tuning (FedPFT), a novel method enhancing FMs adaptation in downstream tasks through FL by two key modules. First, the sub-FM construction module employs a layer-wise com- pression approach, facilitating comprehensive FM fine-tuning across all layers by emphasizing those crucial neurons. Second, the sub-FM alignment module conducts a two-step distillations—layer- level and neuron-level—before and during FL fine- tuning respectively, to reduce error of gradient by accurately aligning sub-FM with FM under theo- retical guarantees. Experimental results on seven commonly used datasets (i.e., four text and three vi- sion) demonstrate the superiority of FedPFT. Our code is available at https://github.com/pzp-dzd/FedPFT.
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Damia´n Ascencio, C. E., A. Herna´ndez Guerrero, J. A. Escobar Vargas, C. Rubio-Arana, and F. Elizalde Blancas F. "Three-Dimensional Numerical Prediction of Current Density for a Constructal Theory-Based Flow Field Pattern." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42449.
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This work presents a three-dimensional numerical prediction of the current density for a Proton Exchange Membrane Fuel Cell (PEMFC) with a tree-like pattern, which is observed in the nature, for the flow field channels. The numerical model considers a complete solution of the Navier-Stokes Equation, the species transport equation and two potential field equations; the model is solved using a finite volume technique assuming isothermal and steady state conditions. The three-dimensional model includes the analysis of: current collectors, flow channels, gas diffusion layers, catalyst layers on both sides of the PEMFC (anode and cathode) and a membrane between the two catalyst layers. The contours of the current density are compared to other models found in the technical literature. The results of the model presented here show that the average current density is larger than for conventional models (such as serpentine flow paths). This suggests that more efficient flow field paths could be build with this constructal theory-based pattern for the flow field channels.
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Olesen, Anders C., Torsten Berning, and Søren Knudsen Kær. "Experimental Validation of Methanol Crossover in a Three-Dimensional, Two-Fluid Model of a Direct Methanol Fuel Cell." In ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2012 6th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fuelcell2012-91170.
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A fully coupled three-dimensional, steady-state, two-fluid, multi-component and non-isothermal DMFC model has been developed in the commercial CFD package CFX 13 (ANSYS inc.). It accounts for the presence of micro porous layers, non-equilibrium phase change, and methanol and water uptake in the ionomer phase of the catalytic layer, and detailed membrane transport of methanol and water. In order to verify the models ability to predict methanol crossover, simulation results need to be compared with experimental measurements under different current densities along with air and methanol stoichiometries. Methanol crossover be indirectly measured based on the combined anode and cathode exhaust CO2 mole fraction and by accounting for the CO2 production at the anode as a function of current density. This approach is simple and assumes that all crossed over methanol is oxidized. Moreover, it takes CO2 crossover into account.
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Ayub, Mohammed, and SanLinn Ismail Kaka. "Automated Hyperparameter Optimization of Convolutional Neural Network (CNN) for First-Break (FB) Arrival Picking." In Gas & Oil Technology Showcase and Conference. SPE, 2023. http://dx.doi.org/10.2118/214253-ms.
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Abstract The Convolutional Neural Network (CNN) has been used successfully to enhance the First-break (FB) automated arrival picking of seismic data. Determining an optimized FB model is challenging as it needs to consider several hyperparameters (HPs) combinations. Tuning the most important HPs manually is infeasible because of a higher number of HP combinations to be tested. Three state-of-the-art automated hyperparameter optimization (HPO) techniques are applied to a CNN model for robust FB arrival picking classification. A CNN model with 4 convolutional (Conv) layers followed by one fully connected (FC) and one output layer is designed to classify the seismic event as FB or non-FB. To control overfitting, dropout (DO), batch normalization are used after every two Conv layers, in addition to only the DO layer after FC. The number and size of kernels, DO rate, Learning rate (Lr), and several neurons in the FC layer are fine-tuned using random search, Bayesian, and Hyper Band HPO techniques. The findings are experimentally evaluated and compared in terms of four performance metrics with respect to classification performance. The five hyperparameters mentioned above are fine-tuned in 13 search spaces for each of the three HPO techniques. From experimental results, applying random search HPO to CNN yields the best accuracy and F1-score of 96.26%, with the best HP combination of 16, 16, 32, and 64 for numbers of kernels in four Conv layers respectively; 2, 2, 2, 5 for the size of kernels in each Conv layer; 0, 0.45, 0.25 for DO rate in each of DO layers; 240 for numbers of neurons in FC layer; and 0.000675 for Lr. In terms of loss on test data, the above combination of HP gives the lowest test loss of 0.1191 among all techniques, making it a robust model. This model outperforms all the other models in terms of precision (96.27%) and recall. Moreover, all HPO models outperformed the baseline in terms of all metrics. The use of DO after Conv layers and FC layers is highly recommended. Moreover, the use of kernel size relatively smaller (i.e. 2) produces the best classification performance. According to the best HP combination results, there is also no harm to use a relatively higher number of neurons in the FC layer than the Conv layer in FB arrival picking classification. The optimal values of Lr range from 0.0001 to 0.000675 depending on the HPO techniques. The model developed in this study improves the accuracy of the auto-picking of FB seismic data and it is anticipated our model to be used more widely in future studies in the processing of seismic data.
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Rahmati, M. T., S. Norouzi, H. Bahai, and G. Alfano. "Experimental and Numerical Study of the Bending Behavior of a Flexible Riser Model." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41816.
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Unbonded flexible risers have become the main means of extracting hydro carbonates from deep waters. So, understanding the complex structural integrity of flexible risers has become a crucial issue for the offshore industry. In this paper, an experimental test and a detailed finite element analyses were carried out on a scaled down model of a flexible riser pipe in order to understand its bending behavior. The model used consists of four layers which include two cylindrical polycarbonate tubes and two steel helical layers. One helical layer, wounded around the pipe assembly, represents the carcass layer in an actual flexible riser whilst the other represents the riser tendon armour layers. The model was subjected to a three point bending load in order to study its bending-curvature behavior. The test data was then compared with the FE numerical results which predicted a similar nonlinear trend but under predicts the strain at tendon layers.
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De Palma, P. "Numerical Analysis of Turbomachinery Flows With Transitional Boundary Layers." In ASME Turbo Expo 2002: Power for Land, Sea, and Air. ASMEDC, 2002. http://dx.doi.org/10.1115/gt2002-30223.
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This paper provides a numerical study of the flow through two turbomachinery cascades with transitional boundary layers. The aim of the present work is to validate some state-of-the-art turbulence and transition models in complex flow configurations. Therefore, the compressible Reynolds-averaged Navier–Stokes equations, with an Explicit Algebraic Stress Model (EASM) and k − ω turbulence closure, are considered. Such a turbulence model is combined with the transition model of Mayle for separated flow. The space discretization is based on a finite volume method with Roe’s approximate Riemann solver and formally second-order-accurate MUSCL extrapolation with minmod limiter. Time integration is performed employing an explicit Runge–Kutta scheme with multigrid acceleration. Firstly, the computations of the two- and three-dimensional subsonic flow through the T106 low-pressure turbine cascade are briefly discussed. Then, a more severe test case, involving shock-induced boundary-layer separation and corner stall is considered, namely, the three-dimensional transonic flow through a linear compressor cascade. In the present paper, calculations of such a transonic flow are presented, employing the standard k − ω model and the EASM, without transition model, and a comparison with the experimental data available in the literature is provided.
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Zhu, Xian-Kui, William R. Johnson, Robert Sindelar, and Bruce Wiersma. "Machine Learning Models of Burst Strength for Defect-Free Pipelines." In ASME 2022 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/pvp2022-84908.
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Abstract Burst strength of line pipes is essential to pipeline design and integrity management. The simple Barlow equation with the ultimate tensile strength (UTS) was often used to estimate burst strength of line pipes. To consider the plastic flow effect of ductile steels, Zhu and Leis (2006, IJPVP) developed an average shear stress yield criterion and obtained the Zhu-Leis solution of burst strength for defect-free pipelines in term of UTS and strain hardening exponent, n, of materials. The Zhu-Leis solution was validated by more than 100 burst tests for various pipeline steels. The Zhu-Leis solution, when normalized by the Barlow strength, is a function of strain hardening rate, n, only, while the experimentally measured burst strength, when normalized by the Barlow strength, is a strong function of n and a weak function of UTS and pipe diameter to thickness ratio D/t. Due to difficulty of three-parameter regressions, this paper adopts the machine learning technology to develop alternative models of burst strength based on a large database of full-scale burst tests. In comparing to the regression, the machine learning method works well for both single and multiple parameters by introducing an artificial neural network (ANN), activation functions and learning algorithm for the network to learn and make predictions. Three ANN models were developed for predicting the burst strength of defect-free pipelines. Model 1 has one input variable and one hidden layer with three neurons; Model 2 has three input variables and one hidden layer with five neurons; and Model 3 has three input variables and two hidden layers with three neurons for the first hidden layer and two neurons for the second hidden layer. Those ANN models were then validated by the full-scale test data and evaluated through comparison with the Zhu-Leis solution and the linear regression result. On this basis, the best ANN model is recommended.
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Sharma, A., S. K. S. Boetcher, W. A. Aissa, and M. J. Traum. "Impact of Interstitial Mass Transport Resistance on Water Vapor Diffusion Through Southern Mills Defender™ 750 Fabric Layers." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44485.
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Textiles maintain wearer comfort by allowing evaporated sweat to permeate through, providing thermal management and keeping skin dry. Each textile layer presents a resistance to mass transport consistent with its physical structure (i.e., thickness, porosity, and tortuosity). However, when textiles are layered, water vapor transport becomes more complex because diffusing molecules must traverse interstitial spaces between layers. Interstitial mass transport resistances of significant magnitude can reduce rates of water vapor transport through layered textile stacks. The prevailing textile mass transport resistance interrogation method is ASTM F1868: “Standard Test Method for Thermal and Evaporative Resistance of Clothing Materials Using a Sweating Hot Plate.” A self-calibrating element of this method is to measure one, two, three, and four fabric layers. Each newly added layer is prescribed to increase the stack mass transport resistance by the integer resistance presented by a single layer with no interstitial resistance consideration. Four improvements to ASTM F1868 are recommended: 1) gravimetric mass transport measurement, 2) a Stefan flow model, 3) correct accounting for apparatus mass transport resistances, and 4) recognizing and measuring interstitial mass transport resistances. These improvements were implemented and evaluated by running tests using Southern Mills Defender™ 750 fabric, the calibration standard used for ASTM F1868, on a new gravimetric experimental apparatus. The mass transport resistance of one fabric layer measured via the gravimetric method is related to the ASTM F1868 value through working fluid properties. Using the gravimetric approach, mass transport resistance for a single layer of calibration fabric was measured at 60.3 ± 14.4 s/m, which is consistent with the prescribed result from ASTM F1868 (after the conversion factor), 73.1 ± 7.3 s/m. The diffusion coefficient for water vapor in air in the fabric pores measured by gravimetric experiment, (2.02 ± 0.59) × 10−5 m2/s, agrees (within experimental uncertainty) with the theoretical value for the experimental conditions, 2.54 × 10−5 m2/s. However, for stacks of two or more calibration fabric layers, the gravimetric approach does not agree with the prescribed ASTM F1868 result due to interstitial mass transport resistance between fabric layers. The measured interstitial resistance value is 23.6 s/m, 39.1% of a single fabric layer, a value too significant to be ignored in engineering analysis.
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Damia´n-Ascencio, C. E., A. Herna´ndez Guerrero, J. A. Escobar Vargas, S. Cano-Adrade, and F. Elizalde Blancas. "Performance Comparison for a Constructal-Based Flow Field Pattern in a Single PEMFC." In ASME 2008 9th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2008. http://dx.doi.org/10.1115/esda2008-59401.
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The present work shows a three-dimensional numerical simulation of a Single Proton Exchange Membrane Fuel Cell (PEMFC) with a constructal-based pattern as a gas distributor. The models are classified according to the proposed angle and bifurcation level. The numerical model considers a complete solution of the Navier-Stokes equations, the species transport equation and two potential field equations; the model is solved using a finite-volume technique assuming isothermal and steady state conditions. The three-dimensional simulation includes nine control volumes: two current collectors, two flow channels, two gas diffusion layers, two catalyst layers and a membrane between the two catalyst layers. The results show that larger values of current density can be obtained in order if the bifurcation levels are increased. This suggests that a better performance is reached when the structure is closer to those structures found in the natural world.
Reports on the topic "Two - three and four layers models"
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Chapman, Ray, Phu Luong, Sung-Chan Kim, and Earl Hayter. Development of three-dimensional wetting and drying algorithm for the Geophysical Scale Transport Multi-Block Hydrodynamic Sediment and Water Quality Transport Modeling System (GSMB). Engineer Research and Development Center (U.S.), 2021. http://dx.doi.org/10.21079/11681/41085.
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The Environmental Laboratory (EL) and the Coastal and Hydraulics Laboratory (CHL) have jointly completed a number of large-scale hydrodynamic, sediment and water quality transport studies. EL and CHL have successfully executed these studies utilizing the Geophysical Scale Transport Modeling System (GSMB). The model framework of GSMB is composed of multiple process models as shown in Figure 1. Figure 1 shows that the United States Army Corps of Engineers (USACE) accepted wave, hydrodynamic, sediment and water quality transport models are directly and indirectly linked within the GSMB framework. The components of GSMB are the two-dimensional (2D) deep-water wave action model (WAM) (Komen et al. 1994, Jensen et al. 2012), data from meteorological model (MET) (e.g., Saha et al. 2010 - http://journals.ametsoc.org/doi/pdf/10.1175/2010BAMS3001.1), shallow water wave models (STWAVE) (Smith et al. 1999), Coastal Modeling System wave (CMS-WAVE) (Lin et al. 2008), the large-scale, unstructured two-dimensional Advanced Circulation (2D ADCIRC) hydrodynamic model (http://www.adcirc.org), and the regional scale models, Curvilinear Hydrodynamics in three dimensions-Multi-Block (CH3D-MB) (Luong and Chapman 2009), which is the multi-block (MB) version of Curvilinear Hydrodynamics in three-dimensions-Waterways Experiments Station (CH3D-WES) (Chapman et al. 1996, Chapman et al. 2009), MB CH3D-SEDZLJ sediment transport model (Hayter et al. 2012), and CE-QUAL Management - ICM water quality model (Bunch et al. 2003, Cerco and Cole 1994). Task 1 of the DOER project, “Modeling Transport in Wetting/Drying and Vegetated Regions,” is to implement and test three-dimensional (3D) wetting and drying (W/D) within GSMB. This technical note describes the methods and results of Task 1. The original W/D routines were restricted to a single vertical layer or depth-averaged simulations. In order to retain the required 3D or multi-layer capability of MB-CH3D, a multi-block version with variable block layers was developed (Chapman and Luong 2009). This approach requires a combination of grid decomposition, MB, and Message Passing Interface (MPI) communication (Snir et al. 1998). The MB single layer W/D has demonstrated itself as an effective tool in hyper-tide environments, such as Cook Inlet, Alaska (Hayter et al. 2012). The code modifications, implementation, and testing of a fully 3D W/D are described in the following sections of this technical note.
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Aiello-Lammens, Matthew E., Robert Anderson, Mary E. Blair, et al. Species Distribution Modeling for Conservation Educators and Practitioners. American Museum of Natural History, 2023. http://dx.doi.org/10.5531/cbc.ncep.0184.
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Models that predict distributions of species by combining known occurrence records with digital layers of environmental variables have much potential for application in conservation. Through using this module, teachers will enable students to develop species distribution models, to apply the models across a series of analyses, and to interpret predictions accurately. In addition to its original components, this module features an updated and condensed synthesis document ("A Brief Introduction to Species Distribution Modeling for Conservation Educators and Practitioners," which provides theoretical and practical guidance for the expanding field of species distribution modeling. The synthesis is supplemented by a new exercise where learners create and optimize species distribution models using Wallace, an R-based GUI (Graphical User Interface) application for ecological modeling that currently focuses on building, evaluating, and visualizing models of species niches and distributions. Additionally, there are four new PowerPoint presentations on species distribution models (the history and theory, data and algorithms, and evaluating SDMs), as well as a presentation on how to use Wallace. The original Synthesis, "Species' Distribution Modeling for Conservation Educators and Practitioners," introduces learners to the modeling approach, outlines key concepts and terminology, and describes questions that may be addressed using the approach. A theoretical framework that is fundamental to ensuring that students understand the uses and limitations of the models is then described. Additionally, it details the main steps in building and testing a distribution model, and describes three case studies that illustrate applications of the models. This module is targeted at a level suitable for teaching graduate students and conservation professionals.
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Carter, T. R., C E Logan, and H. A. J. Russell. Three-dimensional model of dolomitization patterns in the Salina Group A-1 Carbonate and A-2 Carbonate units, Sombra Township, Lambton County, southern Ontario. Natural Resources Canada/CMSS/Information Management, 2024. http://dx.doi.org/10.4095/332363.
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Dolomitization of carbonate rocks is a subject of considerable interest due to association with oil and gas reservoirs and Mississippi Valley Type ore deposits. Conceptual two-dimensional models of dolomitization are common in the literature, however numeric models supported by high quality data are rare to nonexistent. This paper presents three-dimensional (3-D) dolomitization patterns in the Salina Group A-1 Carbonate Unit and A-2 Carbonate Unit located in Sombra Township, Lambton County. The source data consists of percent dolomite measurements collected from 9727 drill cutting samples, stained with alizarin red, from 409 petroleum wells. Numerical interpolants of the percentage of dolomite versus limestone in the two formations are developed within the boundaries of lithostratigraphic formation layers derived from a 3-D geologic model of southern Ontario, published as GSC Open File 8795 (Carter et al. 2021b). The model was developed using Leapfrog© Works software with a 400 m grid resolution. Results show that increased proportions of dolomite vs limestone in both formations are spatially associated with the flanks and crests of pinnacles in the underlying Lockport Group carbonates, over which the B Salt has been dissolved, and the downthrown side of the Dawn Fault and Becher faults. In the A-1 Carbonate there is an increase in dolomite content over a minority of incipient reefs in the Lockport, and in the A-2 Carbonate Unit there is a gradational increase in dolomite content upwards from a basal limestone to 100% dolomite. The cross-cutting relationships of dolomite occurrence in the A-1 Carbonate on the flanks and crests of some pinnacles support a post-depositional burial diagenesis mechanism, consistent with previous interpretations. The pathway for the dolomitizing fluid was laterally through porous and permeable regional paleokarst in the underlying Lockport Group, uppermost Goat Island and Guelph formations, and upwards through the porous reefal carbonates of the pinnacles. Association of dolomitization haloes with dissolution features in halite of the overlying B Salt Unit further suggest that the dolomitizing fluids were also responsible for salt dissolution. The preferential association of dolomite with the Dawn and Becher faults suggest that movement of the dolomitizing fluid was also fault controlled. This project demonstrates the feasibility and merit of assignment and interpolation of attribute values constrained by lithostratigraphic layers in the regional 3-D geologic model of southern Ontario. Spatial associations of dolomite with other geological features are more clearly resolved than in a 2-D study.
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Carter, T. R., C. E. Logan, J K Clark, H. A. J. Russell, E. H. Priebe, and S. Sun. A three-dimensional bedrock hydrostratigraphic model of southern Ontario. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/331098.
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A hydrostratigraphic framework has been developed for southern Ontario consisting of 15 hydrostratigraphic units and 3 regional hydrochemical regimes. Using this framework, the 54 layer 3-D lithostratigraphic model has been converted into a 15 layer 3-D hydrostratigraphic model. Layers are expressed as either aquifer or aquitard based principally on hydrogeologic characteristics, in particular the permeability and the occurrence/absence of groundwater when intersected by a water well or petroleum well. Hydrostratigraphic aquifer units are sub-divided into up to three distinct hydrochemical regimes: brines (deep), brackish-saline sulphur water (intermediate), and fresh (shallow). The hydrostratigraphic unit assignment provides a standard nomenclature and definition for regional flow modelling of potable water and deeper fluids. Included in the model are: 1) 3-D hydrostratigraphic units, 2) 3-D hydrochemical fluid zones within aquifers, 3) 3-D representations of oil and natural gas reservoirs which form an integral part of the intermediate to deep groundwater regimes, 4) 3-D fluid level surfaces for deep Cambrian brines, for brines and fresh to sulphurous groundwater in the Guelph Aquifer, and the fresh to sulphurous groundwater of the Bass Islands Aquifer and Lucas-Dundee Aquifer, 5) inferred shallow karst, 6) base of fresh water, 7) Lockport Group TDS, and 8) the 3-D lithostratigraphy. The 3-D hydrostratigraphic model is derived from the lithostratigraphic layers of the published 3-D geological model. It is constructed using Leapfrog Works at 400 m grid scale and is distributed in a proprietary format with free viewer software as well as industry standard formats.
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Rigotti, Christophe, and Mohand-Saïd Hacid. Representing and Reasoning on Conceptual Queries Over Image Databases. Aachen University of Technology, 1999. http://dx.doi.org/10.25368/2022.89.
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The problem of content management of multimedia data types (e.g., image, video, graphics) is becoming increasingly important with the development of advanced multimedia applications. Traditional database management systems are inadequate for the handling of such data types. They require new techniques for query formulation, retrieval, evaluation, and navigation. In this paper we develop a knowledge-based framework for modeling and retrieving image data by content. To represent the various aspects of an image object's characteristics, we propose a model which consists of three layers: (1) Feature and Content Layer, intended to contain image visual features such as contours, shapes,etc.; (2) Object Layer, which provides the (conceptual) content dimension of images; and (3) Schema Layer, which contains the structured abstractions of images, i.e., a general schema about the classes of objects represented in the object layer. We propose two abstract languages on the basis of description logics: one for describing knowledge of the object and schema layers, and the other, more expressive, for making queries. Queries can refer to the form dimension (i.e., information of the Feature and Content Layer) or to the content dimension (i.e., information of the Object Layer). These languages employ a variable free notation, and they are well suited for the design, verification and complexity analysis of algorithms. As the amount of information contained in the previous layers may be huge and operations performed at the Feature and Content Layer are time-consuming, resorting to the use of materialized views to process and optimize queries may be extremely useful. For that, we propose a formal framework for testing containment of a query in a view expressed in our query language. The algorithm we propose is sound and complete and relatively efficient.
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Rigotti, Christophe, and Mohand-Saïd Hacid. Representing and Reasoning on Conceptual Queries Over Image Databases. Aachen University of Technology, 1999. http://dx.doi.org/10.25368/2022.89.
Full textAbstract:
The problem of content management of multimedia data types (e.g., image, video, graphics) is becoming increasingly important with the development of advanced multimedia applications. Traditional database management systems are inadequate for the handling of such data types. They require new techniques for query formulation, retrieval, evaluation, and navigation. In this paper we develop a knowledge-based framework for modeling and retrieving image data by content. To represent the various aspects of an image object's characteristics, we propose a model which consists of three layers: (1) Feature and Content Layer, intended to contain image visual features such as contours, shapes,etc.; (2) Object Layer, which provides the (conceptual) content dimension of images; and (3) Schema Layer, which contains the structured abstractions of images, i.e., a general schema about the classes of objects represented in the object layer. We propose two abstract languages on the basis of description logics: one for describing knowledge of the object and schema layers, and the other, more expressive, for making queries. Queries can refer to the form dimension (i.e., information of the Feature and Content Layer) or to the content dimension (i.e., information of the Object Layer). These languages employ a variable free notation, and they are well suited for the design, verification and complexity analysis of algorithms. As the amount of information contained in the previous layers may be huge and operations performed at the Feature and Content Layer are time-consuming, resorting to the use of materialized views to process and optimize queries may be extremely useful. For that, we propose a formal framework for testing containment of a query in a view expressed in our query language. The algorithm we propose is sound and complete and relatively efficient.
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Brenan, J. M., K. Woods, J. E. Mungall, and R. Weston. Origin of chromitites in the Esker Intrusive Complex, Ring of Fire Intrusive Suite, as revealed by chromite trace element chemistry and simple crystallization models. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328981.
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To better constrain the origin of the chromitites associated with the Esker Intrusive Complex (EIC) of the Ring of Fire Intrusive Suite (RoFIS), a total of 50 chromite-bearing samples from the Black Thor, Big Daddy, Blackbird, and Black Label chromite deposits have been analysed for major and trace elements. The samples represent three textural groups, as defined by the relative abundance of cumulate silicate phases and chromite. To provide deposit-specific partition coefficients for modeling, we also report on the results of laboratory experiments to measure olivine- and chromite-melt partitioning of V and Ga, which are two elements readily detectable in the chromites analysed. Comparison of the Cr/Cr+Al and Fe/Fe+Mg of the EIC chromites and compositions from previous experimental studies indicates overlap in Cr/Cr+Al between the natural samples and experiments done at &amp;gt;1400oC, but significant offset of the natural samples to higher Fe/Fe+Mg. This is interpreted to be the result of subsolidus Fe-Mg exchange between chromite and the silicate matrix. However, little change in Cr/Cr+Al from magmatic values, owing to the lack of an exchangeable reservoir for these elements. A comparison of the composition of the EIC chromites and a subset of samples from other tectonic settings reveals a strong similarity to chromites from the similarly-aged Munro Township komatiites. Partition coefficients for V and Ga are consistent with past results in that both elements are compatible in chromite (DV = 2-4; DGa ~ 3), and incompatible in olivine (DV = 0.01-0.14; DGa ~ 0.02), with values for V increasing with decreasing fO2. Simple fractional crystallization models that use these partition coefficients are developed that monitor the change in element behaviour based on the relative proportions of olivine to chromite in the crystallizing assemblage; from 'normal' cotectic proportions involving predominantly olivine, to chromite-only crystallization. Comparison of models to the natural chromite V-Ga array suggests that the overall positive correlation between these two elements is consistent with chromite formed from a Munro Township-like komatiitic magma crystallizing olivine and chromite in 'normal' cotectic proportions, with no evidence of the strong depletion in these elements expected for chromite-only crystallization. The V-Ga array can be explained if the initial magma responsible for chromite formation is slightly reduced with respect to the FMQ oxygen buffer (~FMQ- 0.5), and has assimilated up to ~20% of wall-rock banded iron formation or granodiorite. Despite the evidence for contamination, results indicate that the EIC chromitites crystallized from 'normal' cotectic proportions of olivine to chromite, and therefore no specific causative link is made between contamination and chromitite formation. Instead, the development of near- monomineralic chromite layers likely involves the preferential removal of olivine relative to chromite by physical segregation during magma flow. As suggested for some other chromitite-forming systems, the specific fluid dynamic regime during magma emplacement may therefore be responsible for crystal sorting and chromite accumulation.
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Berger, Rutherford C. Foundational Principles in the Development of AdH-SW3, the Three-Dimensional Shallow Water Hydrodynamics and Transport Module within the Adaptive Hydraulics/Hydrology Model. U.S. Army Engineer Research and Development Center, 2022. http://dx.doi.org/10.21079/11681/44560.
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This report details the design and development of the three-dimensional shallow water hydrodynamics formulation within the Adaptive Hydraulics/Hydrology model (AdH-SW3) for simulation of flow and transport in rivers, estuaries, reservoirs, and other similar hydrologic environments. The report is intended to communicate principles of the model design for the interested and diligent user. The design relies upon several layers of consistency to produce a stable, accurate, and conservative model. The mesh design can handle rapid changes in bathymetry (e.g., steep-sided navigation channels in estuaries) and maintain accuracy in density-driven transport phenomena (e.g., thermal, or saline stratification and intrusion of salinity).
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Chapman and Toema. PR-266-09211-R01 Physics-Based Characterization of Lambda Sensor from Natural Gas Fueled Engines. Pipeline Research Council International, Inc. (PRCI), 2012. http://dx.doi.org/10.55274/r0010022.
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The increasingly strict air emission regulations may require implementing Non-Selective Catalytic Reduction (NSCR) systems as a promising emission control technology for stationary rich burn spark ignition engines. Many recent experimental investigations that used NSCR systems for stationary natural gas fueled engines showed that NSCR systems were unable to consistently control the exhaust emissions level below the compliance limits. Modeling of NSCR components to better understand, and then exploit, the underlying physical processes that occur in the lambda sensor and the catalyst media is now considered an essential step toward improving NSCR system performance. This report focuses on modeling the lambda sensor that provides feedback to the air-to-fuel ratio controller. Correct interpretation of the sensor output signal is necessary to achieve consistently low emissions level. The goal of this modeling study is to improve the understanding of the physical processes that occur within the sensor, investigate the cross-sensitivity of various exhaust gas species on the sensor performance, and finally this model serves as a tool to improve NSCR control strategies. This model simulates the output from a planar switch type lambda sensor. The model consists of three modules. The first module models the multi-component mass transport through the sensor protective layer. The second module includes all the surface catalytic reactions that take place on the sensor platinum electrodes. The third module is responsible for simulating the reactions that occur on the electrolyte material and determine the sensor output voltage.
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Wilson, D., Daniel Breton, Lauren Waldrop, et al. Signal propagation modeling in complex, three-dimensional environments. Engineer Research and Development Center (U.S.), 2021. http://dx.doi.org/10.21079/11681/40321.
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The Signal Physics Representation in Uncertain and Complex Environments (SPRUCE) work unit, part of the U.S. Army Engineer Research and Development Center (ERDC) Army Terrestrial-Environmental Modeling and Intelligence System (ARTEMIS) work package, focused on the creation of a suite of three-dimensional (3D) signal and sensor performance modeling capabilities that realistically capture propagation physics in urban, mountainous, forested, and other complex terrain environments. This report describes many of the developed technical capabilities. Particular highlights are (1) creation of a Java environmental data abstraction layer for 3D representation of the atmosphere and inhomogeneous terrain that ingests data from many common weather forecast models and terrain data formats, (2) extensions to the Environmental Awareness for Sensor and Emitter Employment (EASEE) software to enable 3D signal propagation modeling, (3) modeling of transmitter and receiver directivity functions in 3D including rotations of the transmitter and receiver platforms, (4) an Extensible Markup Language/JavaScript Object Notation (XML/JSON) interface to facilitate deployment of web services, (5) signal feature definitions and other support for infrasound modeling and for radio-frequency (RF) modeling in the very high frequency (VHF), ultra-high frequency (UHF), and super-high frequency (SHF) frequency ranges, and (6) probabilistic calculations for line-of-sight in complex terrain and vegetation.