Letteratura scientifica selezionata sul tema "Multi-Group models"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Multi-Group models".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Articoli di riviste sul tema "Multi-Group models":
1
Bichara, Derdei, e Abderrahman Iggidr. "Multi-patch and multi-group epidemic models: a new framework". Journal of Mathematical Biology 77, n. 1 (17 novembre 2017): 107–34. http://dx.doi.org/10.1007/s00285-017-1191-9.
2
Ahmad, Qazi Shoeb, Mohammad Faisal Khan e Naeem Ahmad. "Multi-Criteria Group Decision-Making Models in a Multi-Choice Environment". Axioms 11, n. 11 (21 novembre 2022): 659. http://dx.doi.org/10.3390/axioms11110659.
Abstract (sommario):
The best–worst method (BWM) has recently demonstrated its applicability in addressing various decision-making problems in a practical setting. The traditional BWM method is based on deterministic information gathered from experts as pairwise comparisons of several criteria. The advantage of BWM is that it uses fewer calculations and analyses while maintaining good, acceptable consistency ratio values. A multi-choice best–worst method (MCBWM), which considers several options for pairwise comparison of preferences between the criteria, has recently been developed. The experts are given the option to select values from several comparison scales. The MCBWM technique has been shown to be better. Presenting the options for which an optimal solution has been found simplifies the calculation and establishes the ideal weight values. This study proposes two different mathematical programming models for solving multi-criteria decision-making problems having multiple decision-makers. The two methods are proposed considering the multi-choice uncertainty assumption in pairwise criteria comparisons. Additionally, it considers the best–worst method as the base model. The multi-choice uncertainty is applied to determine the best choice out of multiple choices. It gives a real-life scenario to the decision-making problems. Although there are many other forms of uncertainty, such as fuzzy, intuitionistic fuzzy, neutrosophic, probabilistic, etc., it focuses on choices instead of ambiguity in terms of the probabilistic or fuzzy nature of parameters. The parameter considered as multi-choice is the pairwise comparison. These parameters are handled by applying the Lagrange interpolating polynomial method. The proposed models are novel in terms of their mathematical structure and group decision-making approach. The models are formulated and further validated by solving numerical examples. It provides a framework for solving mcdm problems where the weightage to the decision-makers is also incorporated. The CR values for all the models of example 1 and 2, and the case study has been found acceptable.
3
农, 俊叶. "Stationary Distribution Analysis for Stochastic Multi-Group Models". Advances in Applied Mathematics 10, n. 01 (2021): 1–15. http://dx.doi.org/10.12677/aam.2021.101001.
4
农, 俊叶. "Stationary Distribution Analysis for Stochastic Multi-Group Models". Advances in Applied Mathematics 10, n. 01 (2021): 1–15. http://dx.doi.org/10.12677/aam.2021.101001.
5
Al-Shabi, Mohammad, Chaouki Ghenai, Maamar Bettayeb, Fahad Faraz Ahmad e Mamdouh El Haj Assad. "Estimating PV models using multi-group salp swarm algorithm". IAES International Journal of Artificial Intelligence (IJ-AI) 10, n. 2 (1 giugno 2021): 398. http://dx.doi.org/10.11591/ijai.v10.i2.pp398-406.
Abstract (sommario):
<span id="docs-internal-guid-ea798321-7fff-3e0c-24d7-776c9b1165b3"><span>In this paper, a multi-group salp swarm algorithm (MGSSA) is presented for estimating the photovoltaic (PV) solar cell models. The SSA is a metaheuristic technique that mimics the social behavior of the salp. The salps work in a group that follow a certain leader. The leader approaches the food source and the rest follows it, hence resulting in slow convergence of SSA toward the solution. For several groups, the searching mechanism is going to be improved. In this work, a recently developed algorithm based on several salp groups is implemented to estimate the single-, double-, triple-, Quadruple-, and Quintuple-diode models of a PV solar cell. Six versions of MGSSA algorithms are developed with different chain numbers; one, two, four, six, eight and half number of the salps. The results are compared to the regular particle swarm optimization (PSO) and some of its newly developed forms. The results show that MGSSA has a faster convergence rate, and shorter settling time than SSA. Similar to the inspired actual salp chain, the leader is the most important member in the chain; the rest has less significant effect on the algorithm. Therefore, it is highly recommended to increase the number of leaders and reduce the chain length. Increasing the number of leaders (number of groups) can reduce the root mean squared error (RMSE) and maximum absolute error (MAE) by 50% of its value.</span></span>
6
Cwojdziński, Leszek, Jerzy Lewitowicz e Andrzej Żyluk. "Models of Air Missions / Modele Misji Lotniczych". Journal of KONBiN 22, n. 1 (1 giugno 2012): 35–44. http://dx.doi.org/10.2478/jok-2013-0020.
Abstract (sommario):
Abstract Combat missions of both a single multi-role aircraft and a group of aircraft. Compatibility and readiness - properties determining accomplishment of an air operation. Scenarios of air operations. Models of air-to-air and air-to-surface operations (AAO and ASO, respectively). Computer modelling of air missions.
7
Guo, Ying, Xiaohua Ding e Yingjian Li. "On input-to-state stability for stochastic multi-group models with multi-dispersal". Applicable Analysis 96, n. 16 (21 ottobre 2016): 2800–2817. http://dx.doi.org/10.1080/00036811.2016.1246659.
8
Duan, Rong, Qing Bang Han e Zuo Wang. "Multi-Attribute Group Decision Making Models under Intuitionistic Fuzzy Environment". Applied Mechanics and Materials 263-266 (dicembre 2012): 3225–29. http://dx.doi.org/10.4028/www.scientific.net/amm.263-266.3225.
Abstract (sommario):
In order to solve the problem of multi-attribute group-decision making with the elements of evaluation matrix are intuitionistic fuzzy sets, this paper offers corresponding TOPSIS models based on the information entropy weights and examples to be verified. The examples show the feasibility and effectiveness of the proposed models.
9
Painter, Jay, e Ethan A. Merritt. "TLSMDweb server for the generation of multi-group TLS models". Journal of Applied Crystallography 39, n. 1 (12 gennaio 2006): 109–11. http://dx.doi.org/10.1107/s0021889805038987.
Abstract (sommario):
TheTLSMDweb server extracts information about dynamic properties of a protein based on information derived from a single-crystal structure. It does so by analyzing the spatial distribution of individual atomic thermal parameters present in an input structural model. The server partitions the protein structure into multiple, contiguous chain segments, each segment corresponding to one group in a multi-group description of the protein's overall dynamic motion. For each polypeptide chain of the input protein, the analysis generates the optimal partition into two segments, three segments, … up to 20 segments. Each such partition is optimal in the sense that it is the best approximation of the overall spatial distribution of input thermal parameters in terms ofNchain segments, each acting as a rigid group undergoing TLS (translation/libration/screw) motion. This multi-group TLS model may be used as a starting point for further crystallographic refinement, or as the basis for analyzing inter-domain and other large-scale motions implied by the crystal structure.
10
Fan, Dejun, Pengmiao Hao, Dongyan Sun e Junjie Wei. "Global stability of multi-group SEIRS epidemic models with vaccination". International Journal of Biomathematics 11, n. 01 (gennaio 2018): 1850006. http://dx.doi.org/10.1142/s1793524518500067.
Abstract (sommario):
In this paper, a susceptible–exposed–infective–recovered–susceptible (SEIRS) epidemic model with vaccination has been formulated. We studied the global stability of the corresponding single-group model, multi-group model with strongly connected network and multi-group model without strongly connected network by means of analyzing their basic reproduction numbers and the application of Lyapunov functionals. Finally, we provide some numerical simulations to illustrate our analysis results.
Tesi sul tema "Multi-Group models":
1
Jin, Shaobo. "Essays on Estimation Methods for Factor Models and Structural Equation Models". Doctoral thesis, Uppsala universitet, Statistiska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-247292.
Abstract (sommario):
This thesis which consists of four papers is concerned with estimation methods in factor analysis and structural equation models. New estimation methods are proposed and investigated. In paper I an approximation of the penalized maximum likelihood (ML) is introduced to fit an exploratory factor analysis model. Approximated penalized ML continuously and efficiently shrinks the factor loadings towards zero. It naturally factorizes a covariance matrix or a correlation matrix. It is also applicable to an orthogonal or an oblique structure. Paper II, a simulation study, investigates the properties of approximated penalized ML with an orthogonal factor model. Different combinations of penalty terms and tuning parameter selection methods are examined. Differences in factorizing a covariance matrix and factorizing a correlation matrix are also explored. It is shown that the approximated penalized ML frequently improves the traditional estimation-rotation procedure. In Paper III we focus on pseudo ML for multi-group data. Data from different groups are pooled and normal theory is used to fit the model. It is shown that pseudo ML produces consistent estimators of factor loadings and that it is numerically easier than multi-group ML. In addition, normal theory is not applicable to estimate standard errors. A sandwich-type estimator of standard errors is derived. Paper IV examines properties of the recently proposed polychoric instrumental variable (PIV) estimators for ordinal data through a simulation study. PIV is compared with conventional estimation methods (unweighted least squares and diagonally weighted least squares). PIV produces accurate estimates of factor loadings and factor covariances in the correctly specified confirmatory factor analysis model and accurate estimates of loadings and coefficient matrices in the correctly specified structure equation model. If the model is misspecified, robustness of PIV depends on model complexity, underlying distribution, and instrumental variables.
2
Li, Fengfeng. "Multi-criteria optimization of group replacement schedules for distributed water pipeline assets". Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/66195/1/Fengfeng_Li_Thesis.pdf.
Abstract (sommario):
This thesis presents a multi-criteria optimisation study of group replacement schedules for water pipelines, which is a capital-intensive and service critical decision. A new mathematical model was developed, which minimises total replacement costs while maintaining a satisfactory level of services. The research outcomes are expected to enrich the body of knowledge of multi-criteria decision optimisation, where group scheduling is required. The model has the potential to optimise replacement planning for other types of linear asset networks resulting in bottom-line benefits for end users and communities. The results of a real case study show that the new model can effectively reduced the total costs and service interruptions.
3
Qi, Hui, University of Western Sydney, of Science Technology and Environment College e School of Computing and Information Technology. "Multi-polynomial higher order neural network group models for financial data and rainfall data simulation and prediction". THESIS_CSTE_CIT_Qi_H.xml, 2001. http://handle.uws.edu.au:8081/1959.7/343.
Abstract (sommario):
Multi-Polynomial Higher Order Neural Network Group Models (MPHONNG) program developed by the author will be studied in this thesis. The thesis also investigates the use of MPHONNG for financial data and rainfall data simulation and prediction. The MPHONNG is combined with characteristics of Polynomial function, Trigonometric polynomial function and Sigmoid polynomial function. The models are constructed with three layers Multi-Polynomial Higher Order Neural Network and the weights of the models are derived directly from the coefficents of the Polynomial form, Trignometric polynomial form and Sigmoid polynomial form. To the best of the authors knowledge, it is the first attempt to use MPHONNG for financial data and rainfall data simulation and prediction. Results proved satisfactory, and confirmed that MPHONNG is capable of handling high frequency, high order nonlinear and discontinuous data.Master of Science (Hons)
4
Qi, Hui. "Multi-polynomial higher order neural network group models for financial data and rainfall data simulation and prediction". Thesis, View thesis View thesis, 2001. http://handle.uws.edu.au:8081/1959.7/343.
Abstract (sommario):
Multi-Polynomial Higher Order Neural Network Group Models (MPHONNG) program developed by the author will be studied in this thesis. The thesis also investigates the use of MPHONNG for financial data and rainfall data simulation and prediction. The MPHONNG is combined with characteristics of Polynomial function, Trigonometric polynomial function and Sigmoid polynomial function. The models are constructed with three layers Multi-Polynomial Higher Order Neural Network and the weights of the models are derived directly from the coefficents of the Polynomial form, Trignometric polynomial form and Sigmoid polynomial form. To the best of the authors knowledge, it is the first attempt to use MPHONNG for financial data and rainfall data simulation and prediction. Results proved satisfactory, and confirmed that MPHONNG is capable of handling high frequency, high order nonlinear and discontinuous data.
5
Qi, Hui. "Multi-polynomial higher order neural network group models for financial data and rainfall data simulation & prediction /". View thesis View thesis, 2001. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030328.121924/index.html.
Abstract (sommario):
Thesis (M.Sc. (Hons.))--University of Western Sydney, 2001."A thesis presented to the Department of Computing and Information Systems, University of Western Sydney, Macarthur in partial fulfilment of the requirements for the degree of Master of Science (Honours)" Bibliography : leaves 129-139.
6
Yacheur, Souâd. "Modélisation et étude mathématique de la propagation d’une maladie vectorielle (paludisme) au sein d’une population". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0311.
Abstract (sommario):
L’objectif de cette thèse est l’étude d’une classe de modèles mathématiques décrivant quelques problèmes relatifs à l’infection par le parasite Plasmodium falciparum qui cause le paludisme et dont le vecteur est le moustique.On divise le travail en trois grandes parties, la première partie concerne l’analyse de la propagation du paludisme au sein d’une population isolé. On a étudié la stabilité globale de l'équilibre sans maladie en fonction des différents paramètres épidémiologiques quand nombre de reproduction de base est inférieur à un. Quand ce nombre est supérieur à on a prouvé l’existence d’un unique équilibre endémique. En s'inspirant de l'approche géométrique introduite par Li et Muldowney, on a donné une condition suffisante pour que cet équilibre endémique soit globalement asymptotiquement stable.Un estimateur d'état est construit dans le but d'estimer la taille des différentes classes des populations humaines en utilisant la mesure du nombre de nouveaux humains infectés par unité de temps. Nous avons aussi proposé deux stratégies de contrôle pour éradiquer la maladie. Enfin pour mieux comprendre la dynamique de propagation de la maladie et pour désigner les paramètres les plus influençant, nous avons fait l'étude de la sensibilité locale du nombre de reproduction de base par rapport à chaque paramètre. La deuxième partie est dédiée à l’étude d’un modèle qui décrit l’interaction et la propagation de la maladie au sein d’une population humaine divisée en deux sous-population locaux et non-locaux, la première sous-population suit une croissance linéaire quant à la population des non-locaux suit une croissance logistique au sein de la première. Nous faisons le choix d'étudier l'impact de la migration des personnes d'un pays endémique vers un autre pays déclaré sans maladie ou vers l'éradication de la maladie. Notre analyse a donné des conditions de la persistance de la maladie, nous avons étudié la possibilité de contrôle de la maladie dans un premier temps à travers le contrôle de la capacité limite, puis nous avons développé une méthode basée sur une matrice dite matrice de transmission vectorielle qui a servi à déterminer le lien entre les deux sous-populations et la population des moustiques, et en fonction des valeurs d'entrée de cette dernière dans le but de contrôler la maladie. Par ailleurs une étude de sensibilité locale et globale du niveau d'infecté locaux et non-locaux a été faite pour déterminer les paramètres d'entrées du modèle les plus influençant. La dernière partie est consacrée à l’étude de la dynamique globale des modèles avec de multiples sous-populations qui sont supposés faiblement inter-connectées. Notre travail met en évidence une procédure qui permet d'avoir une analyse complète de beaucoup de systèmes dynamiques modélisant la propagation d'une maladie qui fait intervenir différentes populations. Le but est de pouvoir déterminer la stabilité globale de l'équilibre sans maladie quand le nombre de reproduction de base est inférieur à un ainsi que la stabilité globale des différents types (intérieurs ou frontière) des équilibres endémiques en fonction des différents nombres de reproduction de base locaux et de la nature des interconnexions entre les composantes du réseauThe main purpose of this thesis is to study a class of mathematical models describing some problems related to the infection by the Plasmodium falciparum parasite which causes malaria and whose vector is the mosquito.The work is divided into three main parts, the first part is related to the analysis of the spread of malaria in an isolated population. The global stability of the disease-free equilibrium is studied according to the different epidemiological parameters when the number of basic reproduction is lower than one. When this number is higher than one, the existence of a unique endemic equilibrium is proved. Inspired by the geometric approach introduced by Li and Muldowney, we provided a sufficient condition for this endemic equilibrium to be globally asymptotically stable.A state estimator was constructed to estimate the size of human populations based on the measurement of the number of newly infected humans per unit time. We also proposed two control strategies to eradicate the disease.Finally, to better understand the dynamics of the spread of the disease and to identify the most influential parameters, we have studied the local sensitivity of the number of basic reproduction with respect to each parameter.The second part is about the study of a model that describes the interaction and the spread of the disease within a human population that is divided into two subpopulations, local and non-local. The first subpopulation follows a linear growth while the non-local population follows a logistic growth among the first. We choose to study the impact of the migration of people from an endemic country to another country declared free of the disease or towards the eradication of the disease.Our analysis yielded conditions of the persistence of the disease, we studied the possibility of controlling the disease in a first step through the control of the carrying capacity, then we developed a method based on a matrix called matrix of vectorial transmission which was used to determine the link between the two subpopulations and the population of mosquitoes, according to the values of this matrix entries in order to ensure the control of the disease spread. In addition, a local and global sensitivity study of the level of local and non-local infection was performed to determine the most influential model input parameters.The last part is devoted to the study of the global dynamics of models with multiple subpopulations that are assumed to be weakly interconnected. Our work highlights a process that allows us to perform a complete analysis of many dynamical systems modeling the spread of a disease that involves different populations. The objective is to be able to determine the global stability of the disease-free equilibrium when the basic reproduction number is less than one as well as the global stability of the different types (interior or frontier) of endemic equilibria as a function of the different local basic reproduction numbers and the nature of the interconnections between the network components
7
Porst, Roland. "A new transit system and conceptual models with associated findings to improve urban transport". Thesis, Queensland University of Technology, 2002.
8
Hall, William S. "The Battle Group Logistics Comparative Analysis Model (BGLCAM) : a comparative analysis tool for multi-battle group logistics support". Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA341120.
Abstract (sommario):
Thesis (M.S. in Operations Research) Naval Postgraduate School, September 1997."September 1997." Thesis advisor(s): Mark A. Youngren. Includes bibliographical references (p. 33). Also available online.
9
Shi, Jun-Mei, Ulrich Rohde e Horst-Michael Prasser. "Validation of the multiple velocity multiple size group (CFX10.0 N x M MUSIG) model for polydispersed multiphase flows". Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-28031.
Abstract (sommario):
To simulate dispersed two-phase flows CFD tools for predicting the local particle number density and the size distribution are required. These quantities do not only have a significant effect on rates of mixing, heterogeneous chemical reaction rates or interfacial heat and mass transfers, but also a direct relevance to the hydrodynamics of the total system, such as the flow pattern and flow regime. The Multiple Size Group (MUSIG) model available in the commercial codes CFX-4 and CFX-5 was developed for this purpose. Mathematically, this model is based on the population balance method and the two-fluid modeling approach. The dispersed phase is divided into N size classes. In order to reduce the computational cost, all size groups are assumed to share the same velocity field. This model allows to use a sufficient number of particle size groups required for the coalescence and breakup calculation. Nevertheless, the assumption also restricts its applicability to homogeneous dispersed flows. We refer to the CFX MUSIG model mentioned above as the homogeneous model, which fails to predict the correct phase distribution when heterogeneous particle motion becomes important. In many flows the non-drag forces play an essential role with respect to the bubble motion. Especially, the lift force acting on large deformed bubbles, which is dominated by the asymmetrical wake, has a direction opposite to the shear induced lift force on a small bubble. This bubble separation cannot be predicted by the homogeneous MUSIG model. In order to overcome this shortcoming we developed an efficient inhomogeneous MUSIG model in cooperation with ANSYS CFX. A novel multiple velocity multiple size group model, which incorporates the population balance equation into the multi-fluid modeling framework, was proposed. The validation of this new model is discussed in this report.
10
Shi, Jun-Mei, Ulrich Rohde e Horst-Michael Prasser. "Validation of the multiple velocity multiple size group (CFX10.0 N x M MUSIG) model for polydispersed multiphase flows". Forschungszentrum Dresden-Rossendorf, 2007. https://hzdr.qucosa.de/id/qucosa%3A21630.
Abstract (sommario):
To simulate dispersed two-phase flows CFD tools for predicting the local particle number density and the size distribution are required. These quantities do not only have a significant effect on rates of mixing, heterogeneous chemical reaction rates or interfacial heat and mass transfers, but also a direct relevance to the hydrodynamics of the total system, such as the flow pattern and flow regime. The Multiple Size Group (MUSIG) model available in the commercial codes CFX-4 and CFX-5 was developed for this purpose. Mathematically, this model is based on the population balance method and the two-fluid modeling approach. The dispersed phase is divided into N size classes. In order to reduce the computational cost, all size groups are assumed to share the same velocity field. This model allows to use a sufficient number of particle size groups required for the coalescence and breakup calculation. Nevertheless, the assumption also restricts its applicability to homogeneous dispersed flows. We refer to the CFX MUSIG model mentioned above as the homogeneous model, which fails to predict the correct phase distribution when heterogeneous particle motion becomes important. In many flows the non-drag forces play an essential role with respect to the bubble motion. Especially, the lift force acting on large deformed bubbles, which is dominated by the asymmetrical wake, has a direction opposite to the shear induced lift force on a small bubble. This bubble separation cannot be predicted by the homogeneous MUSIG model. In order to overcome this shortcoming we developed an efficient inhomogeneous MUSIG model in cooperation with ANSYS CFX. A novel multiple velocity multiple size group model, which incorporates the population balance equation into the multi-fluid modeling framework, was proposed. The validation of this new model is discussed in this report.
Libri sul tema "Multi-Group models":
1
Xiang, Wei-Ning. Evaluation of landscape plan alternatives: The application of a fuzzy group multi-criteria decision making model. Amherst: Massachusetts Agricultural Experiment Station, College of Food and Natural Resources, 1987.
2
1957-, Lu Jie, a cura di. Multi-objective group decision making: Methods, software and applications with fuzzy set techniques. London: Imperial College Press, 2007.
3
S, Hall William. The Battle Group Logistics Comparative Analysis Model (BGLCAM): A comparative analysis tool for multi-battle group logistics support. Monterey, Calif: Naval Postgraduate School, 1997.
4
Wei-Ning, Xiang, e Massachusetts Agricultural Experiment Station, a cura di. Evaluation of landscape plan alternatives: (the application of a fuzzy group multi-criteria decision making model). Amherst: Massachusetts Agricultural Station, 1987.
5
Serebryakov, Andrey, e Gennadiy Zhuravlev. Exploitation of oil and gas fields by horizontal wells. ru: INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/971768.
Abstract (sommario):
The textbook describes the design features of offshore horizontal multi-hole production wells, as well as the bottom-hole components of horizontal multi-hole wells. The classification of complications of multi-hole horizontal wells, methods of their prevention and elimination are given. Methods of underground geonavigation of the development of offshore horizontal production wells are proposed. The geological and field bases of operation of horizontal offshore multi-hole oil and gas wells, modes and dynamics of oil, gas and associated water production, methods for calculating dynamic bottom-hole and reservoir pressures are specified. The technologies of operation of offshore horizontal multi-hole wells are presented. The composition and scope of environmental, field and research marine monitoring of the operation of offshore horizontal multi-hole wells and the protection of the marine environment in the production of oil and gas are justified. Meets the requirements of the federal state educational standards of higher education of the latest generation. It is intended for undergraduates of the enlarged group of "Earth Sciences" training areas, as well as for teachers, employees of the fuel and energy complex, industrial geological exploration and oil and gas production enterprises, scientific and design organizations.
6
Ninul, Anatolij Sergeevič. Tenzornaja trigonometrija: Teorija i prilozenija / Theory and Applications /. Moscow, Russia: Mir Publisher, 2004.
7
Ninul, Anatolij Sergeevič. Tensor Trigonometry. Moscow, Russia: Fizmatlit Publisher, 2021.
8
Lu, Jie, Da Ruan, Guangquan Zhang e Fengjie Wu. Multi-objective Group Decision Making: Methods, Software and Applications With Fuzzy Set Techniques (Series in Electrical and Computer Engineering) (Series in Electrical and Computer Engineering). Imperial College Press, 2007.
9
Burda, Zdzislaw, e Jerzy Jurkiewicz. Phase transitions. A cura di Gernot Akemann, Jinho Baik e Philippe Di Francesco. Oxford University Press, 2018. http://dx.doi.org/10.1093/oxfordhb/9780198744191.013.14.
Abstract (sommario):
This article considers phase transitions in matrix models that are invariant under a symmetry group as well as those that occur in some matrix ensembles with preferred basis, like the Anderson transition. It first reviews the results for the simplest model with a nontrivial set of phases, the one-matrix Hermitian model with polynomial potential. It then presents a view of the several solutions of the saddle point equation. It also describes circular models and their Cayley transform to Hermitian models, along with fixed trace models. A brief overview of models with normal, chiral, Wishart, and rectangular matrices is provided. The article concludes with a discussion of the curious single-ring theorem, the successful use of multi-matrix models in describing phase transitions of classical statistical models on fluctuating two-dimensional surfaces, and the delocalization transition for the Anderson, Hatano-Nelson, and Euclidean random matrix models.
10
Whitaker, Matthew C., a cura di. African American Icons of Sport. Greenwood, 2008. http://dx.doi.org/10.5040/9798400607721.
Abstract (sommario):
This title offers an examination of African Americans in sports, from a variety of perspectives and through a lively range of rhetoric styles, and illuminates the history of highly successful and influential individuals, athletes and teams who have transcended mere celebrity to come to represent a given Zeitgeist to a sizable part of the world. It also explores the history and lives of complex, multi-layered personages and groups. Finally, it examines the extent to which modern mass media and popular culture have contributed greatly to the rise, and sometimes fall, of the these powerful symbols of athletic, individual, and group excellence.
Capitoli di libri sul tema "Multi-Group models":
1
Zhou, Chao, Jianhua Qu e Yuting Ling. "Construction of Multi-Tasks Academic Procrastination Model and Analysis of Procrastination Group Characteristics". In Artificial Intelligence in Education: Emerging Technologies, Models and Applications, 327–37. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7527-0_24.
2
Xu, Zeshui, e Xiaoqiang Cai. "Nonlinear Optimization Models for Multi-Attribute Group Decision Making with Intuitionistic Fuzzy Information". In Intuitionistic Fuzzy Information Aggregation, 285–304. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-29584-3_7.
3
Gromann, Dagmar, Lennart Wachowiak, Christian Lang e Barbara Heinisch. "Extracting Terminological Concept Systems from Natural Language Text". In European Language Grid, 289–94. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-17258-8_18.
Abstract (sommario):
AbstractTerminology denotes a language resource that structures domain-specific knowledge by means of conceptual grouping of terms and their interrelations. Such structured domain knowledge is vital to various specialised communication settings, from corporate language to crisis communication. However, manually curating a terminology is both labour- and time-intensive. Approaches to automatically extract terminology have focused on detecting domain-specific single- and multi-word terms without taking terminological relations into consideration, while knowledge extraction has specialised on named entities and their relations. We present the Text2TCS method to extract single- and multi-word terms, group them by synonymy, and interrelate these groupings by means of a pre-specified relation typology to generate a Terminological Concept System (TCS) from domain-specific text in multiple languages. To this end, the method relies on pre-trained neural language models.
4
O’ Mahony, Niall, Anshul Awasthi, Joseph Walsh e Daniel Riordan. "Latent Space Cartography for Geometrically Enriched Latent Spaces". In Communications in Computer and Information Science, 488–501. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-26438-2_38.
Abstract (sommario):
AbstractThere have been many developments in recent years on the exploitation of non-Euclidean geometry for the better representation of the relation between subgroups in datasets. Great progress has been made in this field of Disentangled Representation Learning, in leveraging information geometry divergence, manifold regularisation and geodesics to allow complex dynamics to be captured in the latent space of the representations produced. However, interpreting the high-dimensional latent spaces of the modern deep learning-based models involved is non-trivial. Therefore, in this paper, we investigate how techniques in Latent Space Cartography can be used to display abstract and representational 2D visualisations of manifolds.Additionally, we present a multi-task metric learning model to capture in its output representations as many metrics as is available in a multi-faceted fine-grained change detection dataset. We also implement an interactive visualisation tool that utilises cartographic techniques that allow dimensions and annotations of graphs to be representative of the underlying factors affecting individual scenarios the user can morph and transform to focus on an individual/sub-group to see how they are performing with respect to said metrics.
5
Rebmann, Adrian, Peter Pfeiffer, Peter Fettke e Han van der Aa. "Multi-perspective Identification of Event Groups for Event Abstraction". In Lecture Notes in Business Information Processing, 31–43. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-27815-0_3.
Abstract (sommario):
AbstractIn process mining settings, events are often recorded on a low level and cannot be used for meaningful analysis directly. Moreover, the resulting variability in the recorded event sequences leads to complex process models that provide limited insights. To overcome these issues, event abstraction techniques pre-process the event sequences by grouping the recorded low-level events into higher-level activities. However, existing abstraction techniques require elaborate input about high-level activities upfront to achieve acceptable abstraction results. This input is often not available or needs to be constructed, which requires considerable manual effort and domain knowledge. We overcome this by proposing an approach that suggests groups of low-level events for event abstraction. It does not require the user to provide elaborate input upfront, but still allows them to inspect and select groups of events that are related based on their common multi-perspective contexts. To achieve this, our approach learns representations of events that capture their context and automatically identifies and suggests interesting groups of related events. The user can inspect group descriptions and select meaningful groups to abstract the low-level event log.
6
Qi, Xinxin, Juan Chen e Lin Deng. "CP$$^{3}$$: Hierarchical Cross-Platform Power/Performance Prediction Using a Transfer Learning Approach". In Algorithms and Architectures for Parallel Processing, 117–38. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-22677-9_7.
Abstract (sommario):
AbstractCross-platform power/performance prediction is becoming increasingly important due to the rapid development and variety of software and hardware architectures in an era of heterogeneous multi-core. However, accurate power/performance prediction is faced with an obstacle caused by the large gap between architectures, which is often overcome by laborious and time-consuming fine-grained program profiling on the target platform. To overcome these problems, this paper introduces $$CP^3$$ C P 3 , a hierarchical Cross-platform Power/Performance Prediction framework, which focuses on utilizing architecture differences to migrate built models to target platforms. The core of $$CP^3$$ C P 3 is the three-step hierarchical transfer learning approach, hierarchical division, partial transfer learning, and model fusion, respectively. $$CP^3$$ C P 3 firstly builds a power/performance model on the source platform, then rebuilds it with the reduced training data on the target platform, and finally obtains a cross-platform model. We validate the effectiveness of $$CP^3$$ C P 3 using a group of benchmarks on X86- and ARM-based platforms that use three different types of commonly used processors. Evaluation results show that when applying $$CP^3$$ C P 3 , only 1% of the baseline training data is required to achieve high cross-platform prediction accuracy, with power prediction error being only 0.65%, and performance prediction error being only 4.64%.
7
Donais, Francis Marleau, Irène Abi-Zeid e Roxane Lavoie. "Building a Shared Model for Multi-criteria Group Decision Making". In Lecture Notes in Business Information Processing, 175–86. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-63546-0_13.
8
Suh, Jennifer Jiyoung, e Miriam J. Metzger. "Privacy Beyond the Individual Level". In Modern Socio-Technical Perspectives on Privacy, 91–109. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-82786-1_6.
Abstract (sommario):
AbstractThis chapter examines privacy as a multilevel concept. While current conceptualizations of privacy tend to focus on the individual level, technological advancements are making group privacy increasingly important to understand. This chapter offers a typology of both groups and group privacy to establish a framework for conceptualizing how privacy operates beyond the individual level. The chapter describes several contemporary practices that influence the privacy of multiple actors and considers the dynamics of multi-stakeholder privacy decision-making. Potential tensions that exist between the rights and preferences of individual group members or between individuals and the group as a whole are also examined. Finally, recommendations for tools and other mechanisms to support collaborative privacy management and group privacy protection are provided.
9
Thompson-Bell, Jacob. "6. Working Together Well". In Teaching Music Performance in Higher Education, 165–80. Cambridge, UK: Open Book Publishers, 2024. http://dx.doi.org/10.11647/obp.0398.08.
Abstract (sommario):
This chapter interrogates some of the foundational assumptions of student-centred learning environments (SCLEs), with a view to expanding conventional pedagogical models to account for the “distributive” agency of groups of learners assembled in a classroom. In the first part, the author proposes that learner groups be treated as distributive agential networks, braiding together intrinsic, extrinsic and intratrinsic (i.e. motivation distributed between multiple learners) forms of motivation, thereby to sustain both individual and collective forms of agency. It is argued that greater awareness of how motivation emerges across such multi-dimensional agential networks within the learning environment can enable student-teacher and student-student relationships to be established on a more flexible and equitable basis, so that inventive ways of working can be collectively imagined. In the next part, these distributive agential networks are illustrated with reference to the author’s own teaching practice, working with multidisciplinary groups of music students across conservatoire and university settings in the United Kingdom. This section takes the form of an impressionistic vignette outlining a peer-to-peer feedback session using the Critical Response Process (CRP), a group feedback framework for creative work in any media, originally developed by choreographers Liz Lerman and John Borstel. This classroom situation is then analysed as a classroom “assemblage”, to illustrate how pedagogical models such as CRP draw together the bodies and accumulated beliefs of learner groups into a distributive agential network. The chapter concludes with a reflection on how these approaches can lead to a reappraisal of such fundamental academic principles as freedom of expression and equity between learners. Ultimately, it is proposed that the pursuit of creative and expressive freedoms requires that careful attention is paid to the ways in which individual students and teachers can be assembled to form a learner collective.
10
Zhu, Suguo, Yibing Zhan e Guo Zhao. "Multi-model Lightweight Action Recognition with Group-Shuffle Graph Convolutional Network". In Artificial Intelligence, 609–21. Cham: Springer Nature Switzerland, 2022. http://dx.doi.org/10.1007/978-3-031-20497-5_50.
Atti di convegni sul tema "Multi-Group models":
1
Okoniewski, Piotr, Slawomir Kocon e Jacek Piskorowski. "Allpass Based Multi-Notch IIR Filter with Equalized Group Delay". In 2018 23rd International Conference on Methods & Models in Automation & Robotics (MMAR). IEEE, 2018. http://dx.doi.org/10.1109/mmar.2018.8486096.
2
Chu, Dominique, e David J. Barnes. "Group selection vs multi-level selection: Some example models using evolutionary games". In 2009 IEEE Congress on Evolutionary Computation (CEC). IEEE, 2009. http://dx.doi.org/10.1109/cec.2009.4983028.
3
Xuan Dang, Tien, Soo-Hyung Kim, Hyung-Jeong Yang, Guee-Sang Lee e Thanh-Hung Vo. "Group-level Cohesion Prediction using Deep Learning Models with A Multi-stream Hybrid Network". In ICMI '19: INTERNATIONAL CONFERENCE ON MULTIMODAL INTERACTION. New York, NY, USA: ACM, 2019. http://dx.doi.org/10.1145/3340555.3355715.
4
Agranat, Vladimir M., Sergei V. Zhubrin e Igor Pioro. "Multi-Group Two-Phase Flow Model of Drift Drop Plume". In 2014 22nd International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/icone22-30010.
Abstract (sommario):
A homogeneous two-phase multi-group model of drift drop plumes emerging from natural draft cooling towers has been developed and validated using the experimental data obtained in the 1977 Chalk Point Dye Tracer Experiment (CPDTE). The conservation equations for mass fractions of water droplets having different sizes are solved in addition to the standard conservation equations for mixture mass, momentum, energy, water vapor mass fraction and turbulent quantities (turbulent kinetic energy and its dissipation rate). Extra terms are provided to the conservation equations for mass fractions of liquid water to account for the drift of water drops due to their gravitational settling. Various formulations for drift velocity and terminal velocity have been tested and compared. The phase change effects (condensation, evaporation, solidification and melting) are assumed to be negligible due to specific conditions of the experiment. The droplet-size distribution available at the cooling tower exit and containing the 25 groups of drops is simplified to 11 groups. Also, the 3-group and 1-group options are considered for comparison. The individual drop deposition fluxes and the total deposition flux are calculated and compared with the experimental data available at the sensors located on the 35° arcs at 500 and 1000 m from the cooling tower centerline. The total deposition flux is calculated as a sum of products of individual group mass concentrations of water drops and corresponding terminal velocities. The model has been incorporated into the commercial general-purpose Computational Fluid Dynamics (CFD) code, PHOENICS. The study has demonstrated a good agreement between the CFD predictions and the experimental data on the water vapor plume rise and the total drift deposition fluxes. In particular, the plume rise predictions agree well with experimental values (the errors are from 4% to 34% at different distances from the tower centerline). The predicted deposition fluxes are in agreement with the experimental values within a factor of 1.5, which is well within the industry acceptable error limits (a factor of 3). The model developed is recommended for analyzing the drift drop plumes under the conditions similar to CPDTE conditions of small Stokes numbers. It is easier to use and not less accurate than the multiphase Eulerian-Lagrangian CFD models used recently by various researchers for modeling CPDTE plume. The model has a potential to supplant or complement the latter in the computational analyses of gravitational phenomena in complex two-phase flows in engineering equipment and its environment.
5
Boudjidj, Abdelghani, e Mohammed El Habib Souidi. "A Formal Composition of Multi-Agent Organization based on Category Theory". In 9th International Conference on Foundations of Computer Science & Technology (CST 2022). Academy and Industry Research Collaboration Center (AIRCC), 2022. http://dx.doi.org/10.5121/csit.2022.121909.
Abstract (sommario):
The application of organizational multi-agent systems (MAS) provides the possibility of solving complex distributed problems such as, task grouping mechanisms, supply chain management, and air traffic control. The composition of MAS organizational models can be considered as an effective solution to group different organizational multi-agent systems into a single organizational multi-agent system. The main objective of this paper is to provide a MAS organizational model based on the composition of two organizational models, Agent Group Role (AGR), and Yet Another Multi Agent Model (YAMAM), with the aim of providing a new MAS model combining the concepts of the composed organizational models. Category theory represents the mathematical formalism for studying and modeling different organizations in a categorical way. This paper is mainly based on the idea of modeling the multi-agent organization AGR and YAMAM in a categorical way in order to obtain formal semantic models describing these organizations of MAS, then compose them using also the theory of categories which represents a very sophisticated mathematical toolbox based on composition.
6
Billah, Md Arif, e Imraan Faruque. "The Multi-Agent Group Motions Generated by Models of Insect Small Target Detector Neurons and Feedback". In AIAA SCITECH 2022 Forum. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2022. http://dx.doi.org/10.2514/6.2022-0962.
7
Zhang, Hongmei, e Michael F. Modest. "Multi-Group Full-Spectrum k-Distribution Database for Water Vapor Mixtures in Radiative Transfer Calculations". In ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47321.
Abstract (sommario):
A thorough investigation of the absorption coefficient dependence on temperature and pressure has been performed for water vapor and a 32-group database has been assembled for H2O mixtures at atmospheric pressure, based on the Multi-Group Full-Spectrum Correlated k-distribution model. The method is fully scalable, i.e., spectral groups from the database can be combined to obtain coarser group models (N = 1, 2, 4, …) for greater numerical efficiency (accompanied by slight loss in accuracy). The databases for CO2 and H2O, together with the random-overlap mixture model have been used to simulate a practical combustion problem.
8
Zhang, Hongmei, e Michael F. Modest. "Scalable Multi-Group Full-Spectrum Correlated-K Distributions for Radiative Transfer Calculations". In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33529.
Abstract (sommario):
A new full-spectrum k-distribution method has been developed, in which spectral locations are sorted into M spectral groups, according to their absorption coefficient dependence on (partial) pressure and temperature. Calculating correlated-k full-spectrum k-distributions for each of the M groups, LBL accuracy can be obtained with M ≤ 32. Database values have been assembled for CO2 mixtures at atmospheric pressure. The method is fully scalable, i.e., spectral groups from the database can be combined to obtain coarser group models (M = 1,2,4,···) for greater numerical efficiency (accompanied by slight loss in accuracy).
9
Valentine, Timothy, Kostadin Ivanov, Maria Avramova, Alessandro Petruzzi, Jean-Pascal Hudelot, Upendra Rohatgi e Kiril Velkov. "OECD-NEA Expert Group on Multi-Physics Experimental Data, Benchmarks and Validation". In 2018 26th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icone26-81571.
Abstract (sommario):
High-fidelity, multi-physics modeling and simulation (M&S) tools are being developed and utilized for a variety of applications in nuclear science and technology and show great promise in their abilities to reproduce observed phenomena for many applications. Even with the increasing fidelity and sophistication of coupled multi-physics M&S tools, the underpinning models and data still need to be validated against experiments that may require a more complex array of validation data because of the great breadth of the time, energy and spatial domains of the physical phenomena that are being simulated. The expert group on Multi-Physics Experimental Data, Benchmarks and Validation (MPEBV) of the Nuclear Energy Agency (NEA) of the Organization for Economic Cooperation and Development (OECD) was formed to address the challenges with the validation of such tools. The work of the MPEBV expert group is shared among three task forces to fulfill its mandate and specific exercises are being developed to demonstrate validation principles for common industrial challenges. This paper describes the overall mission of the group, the specific objectives of the task forces, the linkages among the task forces, and the development of a validation exercise that focuses on a specific reactor challenge problem.
10
Ibrar, Muhammad, Mushtaq Ahmad, M. Umar, Masood Habib e Muhammad Iqbal. "Stability analysis of DHT based multi-path routing protocol under group-based mobility models and entity-based mobility models in mobile ad-hoc networks". In 2016 IEEE Information Technology, Networking, Electronic and Automation Control Conference (ITNEC). IEEE, 2016. http://dx.doi.org/10.1109/itnec.2016.7560467.
Rapporti di organizzazioni sul tema "Multi-Group models":
1
Bartlem, Kate, Caitlin Fehily, Olivia Wynne, Lauren Gibson, Simone Lodge, Tara Clinton-McHarg, Julia Dray, Jenny Bowman, Luke Wolfenden e John Wiggers. Initiatives to improve physical health for people in community-based mental health programs. The Sax Institute, agosto 2020. http://dx.doi.org/10.57022/conj2912.
Abstract (sommario):
This Evidence Check commissioned by NSW Ministry of Health aimed to evaluate delivery of physical health interventions for people living with a mental illness, delivered though community mental health programs. The review found that sufficient evidence exists to support a number of interventions, with further evaluation; and identified and describes key characteristics for effectiveness such as duration of the intervention and mode of delivery (e.g. face-to-face or telephone, group or individual). The supported interventions and/or actions included: multi-strategy lifestyle behaviour change interventions; care delivery models including peer-led self-management and staff delivered interventions; integration of new physical health care models or initiatives; referral to other services (e.g. telephone Quitline); assessing barriers and enablers prior to implementation; and the involvement of peer workers and consumers in design and delivery.
2
Reis, Evan. Seismic Performance of Single-Family Wood-Frame Houses: Comparing Analytical and Industry Catastrophe Models (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, dicembre 2020. http://dx.doi.org/10.55461/qmbu3779.
Abstract (sommario):
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group (WG) 6: Catastrophe Modeler Comparisons and focuses on comparing damage functions developed by the PEER–CEA Project with those currently contained in modeling software developed by the three largest insurance catastrophe modelers: RMS, CoreLogic and AIR Worldwide. A semi-blind study was conducted in collaboration with the modeling companies to compare damage estimates for a selection of the Index Buildings developed in the PEER–CEA Project Study. The WG6 Project Team conducted several meetings with these modeling companies to gather feedback on the structure of and assumptions made by the PEER–CEA Project. The comparative results are evaluated and presented herein.
3
Reis, Evan. Development of Index Buildings, (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, novembre 2020. http://dx.doi.org/10.55461/fudb2072.
Abstract (sommario):
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 2: Development of Index Buildings and focuses on the identification of common variations and combinations of materials and construction characteristics of California single-family dwellings. These were used to develop “Index Buildings” that formed the basis of the PEER–CEA Project testing and analytical modeling programs (Working Groups 4 and 5). The loss modeling component of the Project (Working Group 6) quantified the damage-seismic hazard relationships for each of the Index Buildings.
4
Zareian, Farzin, e Joel Lanning. Development of Testing Protocol for Cripple Wall Components (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, novembre 2020. http://dx.doi.org/10.55461/olpv6741.
Abstract (sommario):
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA project is to provide scientifically-based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 3.2 and focuses on Loading Protocol Development for Component Testing. It presents the background, development process, and recommendations for a quasi-static loading protocol to be used for cyclic testing of cripple wall components of wood-frame structures. The recommended loading protocol was developed for component testing to support the development of experimentally informed analytical models for cripple wall components. These analytical models are utilized for the performance-based assessment of wood-frame structures in the context of the PEER–CEA Project. The recommended loading protocol was developed using nonlinear dynamic analysis of representative multi-degree-of-freedom (MDOF) systems subjected to sets of single-component ground motions that varied in location and hazard level. Cumulative damage of the cripple wall components of the MDOF systems was investigated. The result is a testing protocol that captures the loading history that a cripple wall may experience in various seismic regions in California.
5
Acemoglu, Daron, Victor Chernozhukov, Iván Werning e Michael Whinston. Optimal Targeted Lockdowns in a Multi-Group SIR Model. Cambridge, MA: National Bureau of Economic Research, maggio 2020. http://dx.doi.org/10.3386/w27102.
6
Cobeen, Kelly, Vahid Mahdavifar, Tara Hutchinson, Brandon Schiller, David Welch, Grace Kang e Yousef Bozorgnia. Large-Component Seismic Testing for Existing and Retrofitted Single-Family Wood-Frame Dwellings (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, novembre 2020. http://dx.doi.org/10.55461/hxyx5257.
Abstract (sommario):
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. Quantifying the difference of seismic performance of un-retrofitted and retrofitted single-family wood-frame houses has become increasingly important in California due to the high seismicity of the state. Inadequate lateral bracing of cripple walls and inadequate sill bolting are the primary reasons for damage to residential homes, even in the event of moderate earthquakes. Physical testing tasks were conducted by Working Group 4 (WG4), with testing carried out at the University of California San Diego (UCSD) and University of California Berkeley (UCB). The primary objectives of the testing were as follows: (1) development of descriptions of load-deflection behavior of components and connections for use by Working Group 5 in development of numerical modeling; and (2) collection of descriptions of damage at varying levels of peak transient drift for use by Working Group 6 in development of fragility functions. Both UCSD and UCB testing included companion specimens tested with and without retrofit. This report documents the portions of the WG4 testing conducted at UCB: two large-component cripple wall tests (Tests AL-1 and AL-2), one test of cripple wall load-path connections (Test B-1), and two tests of dwelling superstructure construction (Tests C-1 and C-2). Included in this report are details of specimen design and construction, instrumentation, loading protocols, test data, testing observations, discussion, and conclusions.
7
Mojidra, Rushil, e Keri Ryan. Influence of Vertical Ground Motion on Bridges Isolated with Spherical Sliding Bearings. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, dicembre 2019. http://dx.doi.org/10.55461/rynq3624.
Abstract (sommario):
The motivation for this project developed from testing of a full scale building isolated with triple friction pendulum bearings on the E-defense shake table in Japan. The test demonstrated experimentally that the vertical component of ground motion can amplify both the base shear and the story acceleration in the isolated building. Vertical shaking introduced high-frequency variation in the axial force of the bearings, and, consequently, a high-frequency component in the bearing lateral force, which excited higher structural modes in the building. Since vertical bridges are flexible in the vertical direction because of long spans, similar effects may be observed in bridges. The objectives of this study are to develop a physical understanding of the amplification of responses and develop a simplified method to predict amplification of base shear in three-dimensional (3D) shaking relative to two-dimensional (2D) shaking, for bridges isolated with spherical sliding bearings. A series of ground motions with a wide range of vertical shaking intensity were applied to 3D models of bridges isolated with triple pendulum bearings (TPBs), both excluding the vertical component (2D motion) and including the vertical component (3D motion). This enabled the comparison of the bridge response under 2D and 3D shaking such that the direct effect of vertical shaking could be investigated. The selected ground motions were fit to target spectra in the horizontal and vertical directions, and divided into three groups based on vertical peak ground acceleration (PGAV). Multi-span concrete box girder bridges were selected for this study, as they are a prominent bridge type in California, and are suitable for seismic isolation. Models were developed for a 3-span, 45-ft wide, multi-column Base Model bridge; various superstructure and isolation-system parameter variations were implemented to evaluate the effect of these variations on the amplification of base shear. Response histories were compared for a representative motion from each ground-motion group under 2D and 3D shaking. Modal and spectral analyses were conducted to understand dynamic properties and behavior of the bridge under vertical motion. Based on simplified theory, a method to estimate the amplification of base shear due to vertical shaking was developed. The accuracy of the simplified method was assessed through a base shear normalized error metric, and different amplification factors were considered. Response history analysis showed significant amplification of base shear under 3D motion implying that exclusion of vertical component could lead to under estimation of demand shear forces on bridge piers. Deck acceleration spectral response at different locations revealed that a transverse-vertical modal coupling response was present in the Base Model bridge, which led to amplification of deck accelerations in addition to base shear due to excitation of the superstructure transverse mode. The simplified method predicted that in addition to the peak vertical ground acceleration base shear amplification depended on the isolation-system period (radius of curvature) and friction coefficient. The error in the simplified method was approximately constant across the range of isolation-system parameters. Variations in the bridge superstructure or substructure modeling parameters had only a minor effect on the base shear since the deck acts as a single mass sliding on isolators; therefore, the simplified method can be applied to a range of bridge models. The simplified method includes an amplification factor that indirectly represents the dynamic amplification of vertical acceleration from the ground to the isolation system. An amplification factor of 1.0 was found to be sufficiently conservative to estimate the base shear due to 3D shaking. The lack of apparent dynamic amplification could mean that the peak vertical acceleration is out-of-phase with the base shear. The simplified method is more likely to be unconservative for high-intensity vertical ground motions due to the complexities associated with uplift and pounding. Further investigation is recommended to determine the threshold shaking intensity limit for the simplified method.
8
Reis, Evan, Yousef Bozorgnia, Henry Burton, Kelly Cobeen, Gregory Deierlein, Tara Hutchinson, Grace Kang et al. Project Technical Summary (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, dicembre 2020. http://dx.doi.org/10.55461/feis4651.
Abstract (sommario):
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER-CEA Project.” The overall objective of the PEER–CEA project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 7: Reporting and is a summary of the PEER–CEA Project work performed by Working Groups 1–6. This report does not present new information apart from the rest of the project, and its purpose is to serve as a reference for researchers and catastrophe modelers wishing to understand the objectives and key findings of the project. The key overall findings of the PEER–CEA Project are summarized in Chapters 8 and 10, which describe the efforts of the WG5 and WG6 Working Groups. The reader is referred to the individual reports prepared by the Working Groups for comprehensive information on the tasks, methodologies, and results of each.
9
Schiller, Brandon, Tara Hutchinson e Kelly Cobeen. Comparison of the Response of Small- and Large-Component Cripple Wall Specimens Tested under Simulated Seismic Loading (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, novembre 2020. http://dx.doi.org/10.55461/iyca1674.
Abstract (sommario):
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 4: Testing, whose central focus was to experimentally investigate the seismic performance of retrofitted and existing cripple walls. Two testing programs were conducted; the University of California, Berkeley (UC Berkeley) focused on large-component tests; and the University of California San Diego (UC San Diego) focused on small-component tests. The primary objectives of the tests were to develop descriptions of the load-deflection behavior of components and connections for use by Working Group 5 in developing numerical models and collect descriptions of damage at varying levels of drift for use by Working Group 6 in developing fragility functions. This report considers two large-component cripple wall tests performed at UC Berkeley and several small-component tests performed at UC San Diego that resembled the testing details of the large-component tests. Experiments involved imposition of combined vertical loading and quasi-static reversed cyclic lateral load on cripple wall assemblies. The details of the tests are representative of era-specific construction, specifically the most vulnerable pre-1945 construction. All cripple walls tested were 2 ft high and finished with stucco over horizontal lumber sheathing. Specimens were tested in both the retrofitted and unretrofitted condition. The large-component tests were constructed as three-dimensional components (with a 20-ft 4-ft floor plan) and included the cripple wall and a single-story superstructure above. The small-component tests were constructed as 12-ft-long two-dimensional components and included only the cripple wall. The pairing of small- and large-component tests was considered to make a direct comparison to determine the following: (1) how closely small-component specimen response could emulate the response of the large-component specimens; and (2) what boundary conditions in the small-component specimens led to the best match the response of the large-component specimens. The answers to these questions are intended to help identify best practices for the future design of cripple walls in residential housing, with particular interest in: (1) supporting the realistic design of small-component specimens that may capture the response large-component specimen response; and (2) to qualitatively determine where the small-component tests fall in the range of lower- to upper-bound estimation of strength and deformation capacity for the purposes of numerical modelling. Through these comparisons, the experiments will ultimately advance numerical modeling tools, which will in turn help generate seismic loss models capable of quantifying the reduction of loss achieved by applying state-of-practice retrofit methods as identified in FEMA P-1100Vulnerability-Base Seismic Assessment and Retrofit of One- and Two-Family Dwellings. To this end, details of the test specimens, measured as well as physical observations, and comparisons between the two test programs are summarized in this report.
10
Mazzoni, Silvia, Nicholas Gregor, Linda Al Atik, Yousef Bozorgnia, David Welch e Gregory Deierlein. Probabilistic Seismic Hazard Analysis and Selecting and Scaling of Ground-Motion Records (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, novembre 2020. http://dx.doi.org/10.55461/zjdn7385.
Abstract (sommario):
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 3 (WG3), Task 3.1: Selecting and Scaling Ground-motion records. The objective of Task 3.1 is to provide suites of ground motions to be used by other working groups (WGs), especially Working Group 5: Analytical Modeling (WG5) for Simulation Studies. The ground motions used in the numerical simulations are intended to represent seismic hazard at the building site. The seismic hazard is dependent on the location of the site relative to seismic sources, the characteristics of the seismic sources in the region and the local soil conditions at the site. To achieve a proper representation of hazard across the State of California, ten sites were selected, and a site-specific probabilistic seismic hazard analysis (PSHA) was performed at each of these sites for both a soft soil (Vs30 = 270 m/sec) and a stiff soil (Vs30=760 m/sec). The PSHA used the UCERF3 seismic source model, which represents the latest seismic source model adopted by the USGS [2013] and NGA-West2 ground-motion models. The PSHA was carried out for structural periods ranging from 0.01 to 10 sec. At each site and soil class, the results from the PSHA—hazard curves, hazard deaggregation, and uniform-hazard spectra (UHS)—were extracted for a series of ten return periods, prescribed by WG5 and WG6, ranging from 15.5–2500 years. For each case (site, soil class, and return period), the UHS was used as the target spectrum for selection and modification of a suite of ground motions. Additionally, another set of target spectra based on “Conditional Spectra” (CS), which are more realistic than UHS, was developed [Baker and Lee 2018]. The Conditional Spectra are defined by the median (Conditional Mean Spectrum) and a period-dependent variance. A suite of at least 40 record pairs (horizontal) were selected and modified for each return period and target-spectrum type. Thus, for each ground-motion suite, 40 or more record pairs were selected using the deaggregation of the hazard, resulting in more than 200 record pairs per target-spectrum type at each site. The suites contained more than 40 records in case some were rejected by the modelers due to secondary characteristics; however, none were rejected, and the complete set was used. For the case of UHS as the target spectrum, the selected motions were modified (scaled) such that the average of the median spectrum (RotD50) [Boore 2010] of the ground-motion pairs follow the target spectrum closely within the period range of interest to the analysts. In communications with WG5 researchers, for ground-motion (time histories, or time series) selection and modification, a period range between 0.01–2.0 sec was selected for this specific application for the project. The duration metrics and pulse characteristics of the records were also used in the final selection of ground motions. The damping ratio for the PSHA and ground-motion target spectra was set to 5%, which is standard practice in engineering applications. For the cases where the CS was used as the target spectrum, the ground-motion suites were selected and scaled using a modified version of the conditional spectrum ground-motion selection tool (CS-GMS tool) developed by Baker and Lee [2018]. This tool selects and scales a suite of ground motions to meet both the median and the user-defined variability. This variability is defined by the relationship developed by Baker and Jayaram [2008]. The computation of CS requires a structural period for the conditional model. In collaboration with WG5 researchers, a conditioning period of 0.25 sec was selected as a representative of the fundamental mode of vibration of the buildings of interest in this study. Working Group 5 carried out a sensitivity analysis of using other conditioning periods, and the results and discussion of selection of conditioning period are reported in Section 4 of the WG5 PEER report entitled Technical Background Report for Structural Analysis and Performance Assessment. The WG3.1 report presents a summary of the selected sites, the seismic-source characterization model, and the ground-motion characterization model used in the PSHA, followed by selection and modification of suites of ground motions. The Record Sequence Number (RSN) and the associated scale factors are tabulated in the Appendices of this report, and the actual time-series files can be downloaded from the PEER Ground-motion database Portal (https://ngawest2.berkeley.edu/)(link is external).