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B-spline Gaussian Collocation software for Two-Dimensional Parabolic PDEs

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Advances in Applied Mathematics and Mechanics 2013年第4期5卷 528-547页

作者： Zhi Li paul Muir Mathematics and Computing science Saint Mary’s UniversityHalifaxNova ScotiaCanada B3H 3C3

In this paper we describe new B-spline Gaussian collocation software for solving two-dimensional parabolic partial differential equations(PDEs)defined over a rectangular *** numerical solution is represented as a bi-variate piecewise polynomial(using a tensor product B-spline basis)with time-dependent unknown *** coefficients are determined by imposing collocation conditions:the numerical solution is required to satisfy the PDE and boundary conditions at images of the Gauss points mapped onto certain subregions of the spatial *** leads to a large system of time-dependent differential algebraic equations(DAEs)which is solved using the DAE solver,*** provide numerical results in which we use the new software,called BACOL2D,to solve three test problems.

关键词： Collocation B-splines two-dimensional partial differential equations differentialalgebraic equations

The effect of supply disruption in a two-layer supply chain with one retailer and two suppliers with promotional effort under random demand

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Journal of Management Analytics 2023年第1期10卷 22-37页

作者： Totan Garai Arpita paul Department of Mathematics Syamsundar CollegeShyamsundarIndia Department of Mathematics Dinhata CollegeCooch BeharIndia

This paper considers a closed-loop supply chain comprising one retailer and two *** assumes one supplier as the main supplier and another as the *** coordination issue of the supply chain has been discussed in this *** main supplier’s yield is considered subject to *** demand considered here is *** aim to calculate the supplier’s optimum production ***,the retailer’s optimal ordering quantity is found ***,in the centralized supply chain model,we want to maximize the expected profit under certain *** illustrations are discussed to the benefit some characteristic insights over the supply chain model.

关键词： supply chain management random supply uncertain demand disruption

Using Bayesian deep learning approaches for uncertainty-aware building energy surrogate models

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能源与人工智能(英文) 2021年第1期3卷 91-103页

作者： paul Westermann Ralph Evins Energy and Cities Group Department of Civil Engineering University of VictoriaCanada

Fast machine learning-based surrogate models are trained to emulate slow,high-fidelity engineering simulation models to accelerate engineering design *** introduces uncertainty as the surrogate is only an approxi-mation of the original *** methods can quantify that uncertainty,and deep learning models exist that follow the Bayesian *** models,namely Bayesian neural networks and Gaussian process models,enable us to give predic-tions together with an estimate of the model’s *** a result we can derive uncertainty-aware surrogate models that can automatically identify unseen design samples that may cause large emulation *** these samples the high-fidelity model can be queried *** paper outlines how the Bayesian paradigm allows us to hybridize fast but approximate and slow but accurate *** this paper,we train two types of Bayesian models,dropout neural networks and stochastic variational Gaussian Process models,to emulate a complex high dimensional building energy performance simulation *** surrogate model processes 35 building design parameters(inputs)to estimate 12 annual building energy perfor-mance metrics(outputs).We benchmark both approaches,prove their accuracy to be competitive,and show that errors can be reduced by up to 30%when the 10%of samples with the highest uncertainty are transferred to the high-fidelity model.

关键词： surrogate modelling Metamodel Building performance simulation Uncertainty Bayesian deep learning Gaussian Process Bayesian neural network

Application of the Mechanical Threshold stress Model to Large strain Processing

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Materials sciences and Applications 2022年第5期13卷 300-316页

作者： paul s. Follansbee Professor Emeritus Saint Vincent College Latrobe PA USA

Large-strain deformations introduce several confounding factors that affect the application of the Mechanical Threshold stress model. These include the decrease with the increasing stress of the normalized activation energy characterizing deformation kinetics, the tendency toward stage IV hardening at high strains, and the influence of crystallographic texture. Minor additions to the Mechanical Threshold stress model are introduced to account for variations of the activation energy and the addition of stage IV hardening. Crystallographic texture cannot be modeled using an isotropic formulation, but some common trends when analyzing predominantly shear deformation followed by uniaxial deformation are described. Comparisons of model predictions with measurements in copper processed using Equal Channel Angular Pressing are described.

关键词： Mechanical Threshold stress Model Large-strain Deformations ECAP stress-strain Curves shear Deformations Activation Energy strain-Hardening

A Comprehensive Review of Experience with the Application of the Mechanical Threshold stress Model

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Materials sciences and Applications 2023年第5期14卷 299-323页

作者： paul s. Follansbee Professor Emeritus Engineering Department Saint Vincent College Latrobe Pennsylvania USA

Accurate prediction of stress-strain behavior of metals as a function of arbitrary temperature and strain rate paths has remained a challenge. The Mechanical Threshold stress constitutive model is one formalism that has emerged following several decades of research. Vast experience has accumulated with the application of the Mechanical Threshold stress model over a wide variety of pure metals and alloys. Out of this has arisen common trends across metal systems. The magnitude of activation energies presents one example of this, where these variables consistently increase in magnitude as the obstacle to dislocation motion transitions from short range to long range. Trends in strain hardening are also observed. In Face-Centered Cubic metals the magnitude of strain hardening scales with the stacking fault energy;trends in Body-Centered Cubic metals are less clear. Model parameters derived for over twenty metals and alloys are tabulated. Common trends should guide future application of the MTs model and further model development.

关键词： Mechanical Threshold stress Constitutive Behavior Deformation Kinetics strain Hardening Internal state Variable

Domain Decomposition Preconditioners for Discontinuous Galerkin Discretizations of Compressible Fluid Flows

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Numerical Mathematics(Theory,Methods and Applications) 2014年第2期7卷 123-148页

作者： stefano Giani paul Houston school of Engineering and Computing sciences Durham UniversitySouth RoadDurhamDH13LEUK. school of Mathematical sciences University of NottinghamUniversity ParkNottingham NG72RDUK.

In this article we consider the application of schwarz-type domain decomposition preconditioners to the discontinuous Galerkin finite element approximation of the compressible Navier-stokes *** discretize this system of conservation laws,we exploit the(adjoint consistent)symmetric version of the interior penalty discontinuous Galerkin finite element *** define the necessary coarse-level solver required for the definition of the proposed preconditioner,we exploit ideas from composite finite element methods,which allow for the definition of finite element schemes on general meshes consisting of polygonal(agglomerated)*** practical performance of the proposed preconditioner is demonstrated for a series of viscous test cases in both two-and three-dimensions.

关键词： Composite finite element methods discontinuous Galerkin methods domain decomposition schwarz preconditioners compressible fluid flows

Preserving the past or past preserving: sustaining the legacy of postmodern museum architecture

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Built Heritage 2022年第2期6卷 24-42页

作者： paul J.Armstrong paul H.Kapp Illinois school of Architecture University of Illinois at Urbana-Champaign117 Buell Hall611 Taft DriveChampaignIL 61820USA

The publication of Complexity and Contradiction in Architecture in 1964 signaled the end of *** reality was that the modern movement had already jettisoned its ideological underpinnings and had become merely another‘style.’The avant garde architects in Europe and in North America were ready to move on and saw Postmodernism as a liberating antidote to the strictures of high *** architectural styles,which had been vilified as antiquated and out of step with modern culture,were revived,reinterpreted,and ***,Postmodernism,which had burned brightly during the 1970s and 1980s,was superseded by other architectural movements,namely,Deconstructivism,Pluralism,during the waning years of the 12th *** though new building forms and design theory changed during Postmodernism,building technology remained the *** walls continued to be built as skins,comprised of either glass,masonry,metal,or synthetic cladding,which were hung of steel or concrete *** membranes covered essentially flat *** infiltration was managed in ever complex composite wall *** important,environmental systems decoupled nature from interiors and were designed to manage ever demanding humidity control *** the development of new building technology,Modernism severed design style from traditional *** re-introducing historical forms back into architecture,Postmodernism complicated ***,Postmodernism and its successors rarely developed new technological ideas by introducing more intricate building forms,which were based on theoretical ideas rather than technical ones,while continuing to employ Modernism building technology into their *** inherent paradox is the most consequential challenge in preserving ***,approximately 40 years after its inception,we must consider if,in some *** it tenable to preserve Postmodern buildings?This paper reasse

关键词： Postmodernism Modern movement Preservation Museums Materials Technology Moisture Memory Adaptation

Incident frailty and cognitive impairment by heart failure status in older patients with atrial fibrillation: the sAGE-AF study

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Journal of Geriatric Cardiology 2020年第11期17卷 653-658页

作者： Wei-Jia WANG Darleen Lessard Jane saczynski Robert J Goldberg Alan s.Go Tenes paul Ely Gracia David D McManus Department of Medicine University of Massachusetts Medical SchoolWorcesterMAUSA Department of Population and Quantitative Health sciences University of Massachusetts Medical SchoolWorcesterMAUSA Department of Pharmacy and Health system sciences Northeastern UniversityBostonMAUSA Division of Research Kaiser Permanente Northern CaliforniaOaklandCAUSA

Background Atrial fibrillation(AF) and heart failure(HF) frequently co-occur in older individuals. Among patients with AF, HF increases risks for stroke and death, but the associations between HF and incident cognition and physical impairment remain unknown. We aimed to examine the cross-sectional and prospective associations between HF, cognition, and frailty among older patients with AF. Methods The sAGE-AF(systematic Assessment of Geriatric Elements in AF) study enrolled 1244 patients with AF(mean age 76 years, 48% women) from five practices in Massachusetts and Georgia. HF at baseline was identified from electronic health records using ICD-9/10 codes. At baseline and 1-year, frailty was assessed by Cardiovascular Health survey score and cognition was assessed by the Montreal Cognitive Assessment. Results Patients with prevalent HF(n = 463, 37.2%) were older, less likely to be non-Hispanic white, had less education, and had greater cardiovascular comorbidity burden and higher CHA2 Ds2 VAsC and HAs-BLED scores than patients without HF(all P's sted regression models, HF(present vs. absent) was associated with both prevalent frailty(adjusted odds ratio [a OR]: 2.38, 95% confidence interval [CI]: 1.64-3.46) and incident frailty at 1 year(a OR: 2.48, 95% CI: 1.37-4.51). HF was also independently associated with baseline cognitive impairment(a OR: 1.60, 95% CI: 1.22-2.11), but not with developing cognitive impairment at 1 year(a OR 1.04, 95%CI: 0.64-1.70). Conclusions Among ambulatory older patients with AF, the co-existence of HF identifies individuals with physical and cognitive impairments who are at higher short-term risk for becoming frail. Preventive strategies to this vulnerable subgroup merit consideration.

关键词： Atrial fibrillation Cognitive impairment Heart failure Frailty

Equal sex Ratios of a Marine Green Alga, Bryopsis plumosa

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Journal of Integrative Plant Biology 2008年第6期50卷 648-652页

作者： Tatsuya Togashi paul Alan Cox Marine Biosystems Research Center Chiba University Institute for Ethnomedicine Box 3464 Jackson Hole Wyoming 83001 USA Institute for Ethnomedicine Box 3464 Jackson Hole

By finding some important culture conditions as below, we succeeded in experimentally controlling the whole life history of a dioecious marine green alga, Bryopsis plumosa （Hudson） C. Agardh. In this study, we focused on the primary and secondary sex ratios （i.e. at inception and maturity） using these culture techniques. Gametogenesis was induced by culturing haploid gametophytes with Provasoli＇s enriched seawater （PEs） medium under a 14：10 h light： dark cycle at 14 ℃. Formed zygotes grew into diploid sporophytes, which were cultured for 3 months with PEs medium under a 14：10 h light ： nbsp;dark cycle at 18℃. Then they were transferred into schreiber medium and cultured under a 10：14 h light： dark cycle at 22℃. Within 1 week, zoosporogenesis was observed. Zoospores were released within a couple of days. Each zoospore soon germinated and grew into a unisexual gametophyte. The primary sex ratio was examined in gametophytes that originated from a single sporophyte. The secondary sex ratio was studied in the field. Both were estimated as 1：1. synchronized meiotic cell divisions might occur during zoosporogenesis dividing each sex-determining factor evenly among zoospores. Given the equal sex ratio at maturity, there seems to be no environmental factor that differentially affects the survival of male or female gametophytes in nature.

关键词： algal culture Bryopsis green algae life history sex ratio.