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Bayesian inference for dynamical systems

2004年

作者： weston Richard

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Infectious Disease Modelling 2020年第1期5卷 221-232页

作者： weston C.Roda Department of Mathematical and Statistical Sciences University of AlbertaEdmontonAB T6G 2G1Canada

Bayesian inference is a common method for conducting parameter estimation for dynamical *** the prevalent use of Bayesian inference for performing parameter estimation for dynamical systems,there is a need for a formalized and detailed *** paper presents a comprehensive methodology for dynamical system parameter estimation using Bayesian inference and it covers utilizing different distributions,Markov Chain Monte Carlo(MCMC)sampling,obtaining credible intervals for parameters,and prediction intervals for solutions.A logistic growth example is given to illustrate the methodology.

关键词： Bayesian Inference Model fitting Data Dynamical system Mathematical model

Dynamic characteristics of a switch and crossing on the West Coast main line in the UK

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Railway Engineering Science 2022年第2期30卷 183-203页

作者： Jou-Yi Shih Paul weston Mani Entezami Clive Roberts Birmingham Centre for Railway Research and Education University of BirminghamBirmingham B152TTUK ZynaMic Engineering AB 12070 StockholmSweden

Railway switches and crossings constitute a small fraction of linear track length but consume a large proportion of the railway track system maintenance *** switch and crossing(S&C)faults rarely prevent trains from running,switches and crossings are the source of many faults and need continual *** the rare occasions when trains are prevented from running the cost of the disruption is very *** monitoring of the point operating equipment that moves the switchblades has been in use for many years but condition monitoring of the state of the switch in terms of the support and mechanical damage as trains pass over has only recently started to become *** this end,it is important to understand the correlation between S&C faults and sensor data that can detect those *** paper assesses some of the data collected from multiple sensors variously positioned on and around a switch and crossing on the UK mainline for a few days of normal train ***,geophones,and strain gauges were installed at the locations where they were anticipated to be most *** at the load transfer point on the crossing nose were estimated from two separate strain gauge bridges and possible use of acceleration on the crossing is *** between different data are analysed and assessed and correlation between peak estimated load transfer forces and accelerations is *** on the analysis,conclusions are drawn about the different types of dynamic information around S&Cs that can be obtained from a variety of sensor types.

关键词： Railway Accelerometer Condition monitoring Impact force Switch and crossing Strain gauge

Abscisic Acid Receptors:Past,Present and Future

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Journal of Integrative Plant Biology 2011年第6期53卷 469-479页

作者： Jianjun Guo Xiaohan Yang David J. weston Jin-Gui Chen Department of Genetics Harvard Medical School Boston Massachusetts 02114-2790 USA Department of Molecular Biology Massachusetts General Hospital Boston Massachusetts 02114-2790 USA Biosciences Division Oak Ridge National Laboratory Oak Ridge TN 37831-6422 USA

acid （ABA） is the key plant stress hormone. Consistent with the earlier studies in support of the presence of both membrane- and cytoplasm-localized ABA receptors, recent studies have identified multi- ple ABA receptors located in various subcellular locations. These include a chloroplast envelope-localized receptor （the H subunit of Chloro- plast Mg2＋-chelatase/ABA Receptor）, two plasma membrane-localized receptors （G-protein Coupled Receptor 2 and GPCR-type G proteins）, and one cytosol/nucleus-localized Pyrabactin Resistant （PYR）/PYR-Like （PYL）/Regulatory Component of ABA Receptor 1 （RCAR）. Although the downstream molecular events for most of the identified ABA receptors are currently unknown, one of them, PYR/PYL/RCAR was found to directly bind and regulate the activity of a long-known central regulator of ABA signaling, the A-group protein phosphatase 2C （PP2C）. Together with the Sucrose Non-fermentation Kinase Subfamily 2 （SnRK2s） protein kinases, a central signaling complex （ABA-PYR-PP2Cs-SnRK2s） that is responsible for ABA signal perception and transduction is supported by abundant genetic, physiological, biochemical and structural evidence. The identification of multiple ABA receptors has advanced our understanding of ABA signal perception and transduction while adding an extra layer of complexity.

关键词： ABA ChlH/ABAPJCCH/GUN5 FCA GCR2 GTGIlGTG2 PYLIPYL/RCAR.

Using Bayesian multitemporal classification to monitor tropical forest cover changes in Kalimantan,Indonesia

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International Journal of Digital Earth 2022年第1期15卷 2061-2077页

作者： Inggit Lolita Sari Christopher J.weston Glenn J.Newnham Liubov Volkova Faculty of Science School of Ecosystem and Forest SciencesThe University of MelbourneCreswickAustralia Research Center for Remote Sensing National Research and Innovation Agency (BRIN)JakartaIndonesia CSIRO Land and Water Clayton SouthAustralia

Significant areas of native forest in Kalimantan,on the island of Borneo,have been cleared for the expansion of plantations of oil palm and *** this study multisource remote sensing was used to develop a time series of land cover maps that distinguish native forest from *** a study area in east Kalimantan,Landsat images were combined with either ALOS PALSAR or Sentinel-1 images to map four land cover classes(native forest,oil palm plantation,rubber plantation,non-forest).Bayesian multitemporal classification was applied to increase map accuracy and maps were validated using a confusion matrix;final map overall accuracy was>90%.Over 18 years from 2000 to 2018 nearly half the native forests in the study area were converted to either non-forest or plantations of either rubber or oil palm,with the highest losses between 2015 and *** upwards from 2008 large areas of degraded or cleared forests,mapped as non-forest,were converted to oil palm *** of native forests to plantation mainly occurred in lowland and wetland forest,while significant forest regrowth was detected in degraded *** maps will help Indonesia with strategies and policies for balancing economic growth and conservation.

关键词： Multitemporal classification Bayesian networks Landsat ALOS PALSAR sentinel-1 Indonesia

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Eaglemania

Eaglemania

Concept development and testing of the UK’s first hydrogenhybrid train(HydroFLEX)

作者： edited by Victoria weston.

来源：南通市图书馆图书评论

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Railway Engineering Science 2021年第3期29卷 248-257页

作者： Charles Calvert Jeff Allan Peter Amor Stuart Hillmansen Clive Roberts Paul weston Birmingham Centre for Railway Research and Education School of EngineeringUniversity of BirminghamEdgbastonBirmingham B152TTUK Jeff Vehicles Ltd BeavercreekUSA

In October 2018,Porterbrook and the University of Birmingham announced the HydroFLEX project,to demonstrate a hydrogen-hybrid modified train atRail Live *** concept of modifying a Class 319 Electric Multiple Unit was developed,with equipment including a fuel cell stack,traction battery,24 V control system and hydrogen storage elements to be mounted inside one of the *** was followed by procurement of a fuel cell stack,traction batteries,and control equipment,which was then installed inside the train,being fixed to the seat *** substantial change from the concept was the provision of considerably more hydrogen storage than the minimum necessary,providing the train with more potential to be further modified to allow for higher speed mainline *** the Rail Live exhibition where HydroFLEX was demonstrated,numerous modifications were performed to increase the reliability and power of the HydroFLEX train,primarily concerned with modifying the base train logic,with the aim of a successfulmainline *** this effort was a multitude of documentation concerning safety,operations,and approvals to gain approvals from the relevant approvals *** project demonstrated the feasibility of using hydrogen fuel cells as an autonomous fuel for railway propulsion systems,which has the potential for full decarbonisation.

关键词： Hydrogen Fuel cell Hybrid Systems engineering

Finite-size correction for slab supercell calculations of materials with spontaneous polarization

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npj Computational Materials 2021年第1期7卷 520-528页

作者： Su-Hyun Yoo Mira Todorova Darshana Wickramaratne Leigh weston Chris GVan de Walle Jörg Neugebauer Department of Computational Materials Design Max-Planck-Institut für Eisenforschung GmbHDüsseldorfGermany Materials Department University of California Santa BarbaraSanta BarbaraCAUSA Center for Computational Materials Science US Naval Research LaboratoryWashingtonDCUSA

The repeated slab approach has become a de facto standard to accurately describe surface properties of materials by density functional theory calculations with periodic boundary *** materials exhibiting spontaneous polarization,we show that the conventional scheme of passivation with pseudo hydrogen is unable to realize a charge-neutral *** presence of a net surface charge induces via Gauss’s law a macroscopic electric field through the slab and results in poor size convergence with respect to the thickness of the *** propose a modified passivation method that accounts for the effect of spontaneous polarization,describes the correct bulk limits and boosts convergence with respect to slab *** robustness,reliability,and superior convergence of energetics and electronic structure achieved by the proposed method are demonstrated using the example of polar ZnO surfaces.

关键词： surface convergence size

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数字学习生态系统中的电子课本(英文)

华东师范大学学报（自然科学版） 2014年第2期 98-115页

作者： C.weston 英国学校学习科技、多塞特郡、T63TN 英国

本文认为,教育在本质上是交互性的而不只是信息的传播.如果遵循这个理论,尽管商业电子书作为独立的产品是可行的,但是电子课本还需要嵌入一个更广泛的数字生态系统来学习.这个生态系统,将包括许多不同形式的软件,提供交互性,报告交互性... 详细信息

本文认为,教育在本质上是交互性的而不只是信息的传播.如果遵循这个理论,尽管商业电子书作为独立的产品是可行的,但是电子课本还需要嵌入一个更广泛的数字生态系统来学习.这个生态系统,将包括许多不同形式的软件,提供交互性,报告交互性的成果,分析个别学生的能力和管理他们的进展.在这样的生态系统中,电子课本在支持开放标准的互操作性上发挥着至关重要的作用.本文将反映一些ISO/IEC研究中的主要结果.

关键词：数字学习生态系统电子课文 ISO IEC

Speckle Reduction in Imaging Projection Systems

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Optics and Photonics Journal 2012年第4期2卷 338-343页

作者： weston Thomas Christopher Middlebrook Electrical and Computer Engineering Department Michigan Technological University Houghton USA

Diffractive diffusers (phase gratings) are routinely used for homogenizing and beam shaping for laser beam applications. Another use for diffractive diffusers is in the reduction of speckle for pico-projection systems. While diffusers are unable to completely eliminate speckle they can be utilized to decrease the resultant contrast to provide a more visually acceptable image. Research has been conducted to quantify and measure the diffusers overall ability in speckle reduction. A theoretical Fourier optics model is used to provide the diffuser’s stationary and in-motion performance in terms of the resultant contrast level. Contrast measurements of two diffractive diffusers are calculated theoretically and compared with experimental results. Having a working theoretical model to accurately predict the performance of the diffractive diffuser allows for the verification of new diffuser designs specifically for pico-projection system applications.

关键词： Diffractive Diffusers Speckle Contrast Reduction Laser Pico-Projectors