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A-posteriori error estimation for second order mechanical systems

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Acta Mechanica Sinica 2012年第3期28卷 854-862页

作者： Thomas Ruiner jrg Fehr bernard Haasdonk Peter Eberhard Institute of Engineering and Computational Mechanics University of StuttgartPfaffenwaldring 970569 StuttgartGermany Institute of Applied Analysis and Numerical Simulation University of StuttgartPfaffenwaldring 5770569 StuttgartGermany

One important issue for the simulation of flexible multibody systems is the reduction of the flexible bodies de- grees of freedom. As far as safety questions are concerned knowledge about the error introduced by the reduction of the flexible degrees of freedom is helpful and very important. In this work, an a-posteriori error estimator for linear first order systems is extended for error estimation of me- chanical second order systems. Due to the special second order structure of mechanical systems, an improvement of the a-posteriori error estimator is achieved. A major advan- tage of the a-posteriori error estimator is that the estimator is independent of the used reduction technique. Therefore, it can be used for moment-matching based, Gramian matrices based or modal based model reduction techniques. The capability of the proposed technique is demon- strated by the a-posteriori error estimation of a mechanical system, and a sensitivity analysis of the parameters involved in the error estimation process is conducted.

关键词： A-posteriori error estimator. Flexible multibodysystems Model reduction

Effects of management regimes on carbon sequestration under the Natural Forest Protection Program in northeast China

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journal of Forestry Research 2018年第5期29卷 1187-1194页

作者： Linhai jiang Wei Zhao bernard j.Lewis Yawei Wei Limin Dai State Key Laboratory of Forest and Soil Ecology Institute of Applied Ecology Chinese Academy of SciencesShenyang 110164 People's Republic of China University of Chinese Academy of Sciences Beijing 100101People's Republic of China Department and Research Center of the State Post Bereau Beijing 100000 People's Republic of China Dalian Institute of Software and Service Outsourcing Dalian 106000 People's Republic of China Shenyang Agricultural University Shenyang 110000People's Republic of China

Carbon sinks constitute an important element within the complex phenomenon of global climate change,and forest ecosystems are important global carbon *** Natural Forest Protection Program（NFPP） is an ecological program in China that was established after catastrophic flooding in the country in *** goals of the NFPP are to curb the deterioration of the ecological environment,strengthen the protection and restoration of habitat to increase biodiversity,and rehabilitate natural forests to support sustainable development in forest *** study looked at changes in carbon sequestration in a forested area of northeast China after the inception of the *** program divides China＇s natural forests into three classes—commercial and two types of noneconomic forests—that are subject to management regimes prescribing varying levels of timber harvest,afforestation,and *** the 18-year period from 1998 to 2015,the total amount of carbon sequestration increased at an average annual rate of 0.04 MT *** trend reflects a transformation of forest management practices after implementation of the NFPP that resulted in prohibited and/or restricted logging and tighter regulation of allowable harvest levels for specific *** documenting this trend,guidelines for more effective implementation of forestry programs such as the NFPP in other countries in the future are also suggested.

关键词： Natural Forest Protection Program(NFPP) Carbon sequestration San Chazi Forestry Bureau China forestry

Drought can offset potential water use efficiency of forest ecosystems from rising atmospheric CO2

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journal of Environmental Sciences 2020年第4期32卷 262-274页

作者： Ning Liu jatin Kala Shirong Liu Vanessa Haverd bernard Dell Keith R.j.Smettem Richard j.Harper Environmental and Conservation Sciences Murdoch UniversityMurdochWA 6150 Australia Research Institute of Forest Ecology Environment and ProtectionChinese Academy of ForestryBeijing 10091 China CSIRO Oceans&Atmosphere ACT 2600 Australia

Increasing atmospheric CO2 is both leading to climate change and providing a potential fertilisation effect on plant ***,southern Australia has also experienced a significant decline in rainfall over the last 30 years,resulting in increased vegetative water *** better understand the dynamics and responses of Australian forest ecosystems to drought and elevated CO2,the magnitude and trend in water use efficiency(WUE)of forests,and their response to drought and elevated CO2 from 1982 to 2014 were analysed,using the best available model estimates constrained by observed fluxes from simulations with fixed and time-varying *** ratio of gross primary productivity(GPP)to evapotranspiration(ET)(WUEe)was used to identify the ecosystem scale WUE,while the ratio of GPP to transpiration(Tr)(WUEc)was used as a measure of canopy scale *** increased significantly in northern Australia(p<0.001)for woody savannas(WSA),whereas there was a slight decline in the WUE of evergreen broadleaf forests(EBF)in the southeast and southwest of *** lag of WUEc to drought was consistent and relatively short and stable between biomes(<3 months),but notably varied for WUEe,with a long time-lag(mean of 10 months).The dissimilar responses of WUEe and WUEc to climate change for different geographical areas result from the different proportion of Tr in ***2 fertilization and a wetter climate enhanced WUE in northern Australia,whereas drought offset the CO2 fertilization effect in southern Australia.

关键词： Water use efficiency Elevated CO2 Carbon sequestration,drought Forest Australia

Spatio-Temporal evolutive Data Infrastructure: a Spatial Data Infrastructure for managing data flows of Territorial Statistical Information

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International journal of Digital Earth 2017年第3期10卷 257-283页

作者： Camille bernard Marlène Villanova-Oliver jérôme Gensel Benoit Le Rubrus Univ.Grenoble Alpes CNRSLIGGrenobleFrance

The observation of demographical,economical or environmental indicators over time through maps is *** enables analysing territories and helps stakeholders to take ***,the understanding of Territorial Statistical Information(TSI)is compromised unless comprehensive description of both the statistical methodology used and the spatial and temporal references are ***,in this paper,we stress the importance of metadata descriptions and of their quality that helps assessing data ***,time-series of such TSI are *** enable analysing a territory over a long period of time and likewise judging the effectiveness of *** light of these observations,we present Spatio-Temporal evolutive Data Infrastructure(STeDI)an innovative Spatial Data Infrastructure(SDI)that enriches the description of a Digital Earth,providing a virtual representation of territories and of their evolution through statistics and *** aims at managing a whole dataflow of multi-dimensional,multi-scale and multi-temporal TSI,from their acquisition to their dissemination to scientists and *** content of this SDI evolves autonomously thanks to automated processes and to a Web platform that help improving the quality of datasets uploaded by ***,STeDI allows visualizing up-to-date time-series reflecting the human activities on a given *** helps policy-makers in their decision-making process.

关键词： Spatial Data Infrastructure Territorial Statistical Information metadata data quality INSPIRE

Elevated temperature intensity,timing,and duration of exposure affect soybean internode elongation,mainstem node number,and pod number per plant

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The Crop journal 2018年第2期6卷 148-161页

作者： Leon Hartwell Allen jr. Lingxiao Zhang Kenneth j.Boote bernard A.Hauser U.S.Department of Agriculture-Agricultural Research Service GainesvilleFL 32608USA Department of Agronomy University of FloridaGainesvilleFL 32611USA Department of Biology University of FloridaGainesvilleFL 32611USA

A study was conducted in four compartments of a polycarbonate greenhouse at Gainesville,FL, USA to investigate how a soybean(Glycine max L. Merr.) cultivar, Maverick(maturity group III, indeterminate), responded to three elevated temperatures, ELT,(day/night of 34/26 °C, 38/30 °C, and 42/34 °C) in comparison to a control growth temperature(30/22 °C).Carbon dioxide(CO_2) concentration was maintained at 700 μmol mol^(-1) in each compartment by a processor controlled air-sampling and CO_2-injection system. Three sequential experiments were conducted at different times of year(summer, autumn, and early spring)to investigate the effect of intensity, timing, and duration of ELT on soybean node number,internode elongation, mainstem length, and number of pods set per plant. At the control temperature, the soybean plants grown in the polycarbonate greenhouse were taller than field-grown plants. When plants were grown under continuous ELT applied soon after sowing or at initial flowering, the number of nodes increased with increasing ELT intensity,whereas the length of individual internodes decreased. When ELT treatment was applied during the beginning of flowering stage(R1–R2) or earlier, more nodes were produced and the length of affected internodes was decreased. When the ELT was imposed later at reproductive stage R5+ just before the beginning of seed filling, effects on node numbers and internode lengths were negligible. Short-term(10-day) duration of ELT applied at four stages from V3 to R5+ did not significantly affect final mean numbers of nodes or mean mainstem lengths. Possible mechanisms of elevated temperature effects on soybean internode elongation and node number(internode number) are discussed. Total pod numbers per plant increased linearly with mainstem node numbers and mainstem ***, total pod numbers per plant were greatest at 34/26 °C rather than at the control temperature of 30/22 °C(and remained high at 38/30 °C). Mild increases in temperatu

关键词： Elevated temperature Internode elongation Node number Pod yield Soybean phenology

Payroll accounting / SouthWestern's 2002 ed.

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Payroll accounting / 2000 ed.

2002年

作者： Bieg bernard j.

来源：畅想之星图书光盘版（南... 评论

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Finding Dutch natives in online forums

2000年

作者： Bieg bernard j.

来源：畅想之星图书光盘版（南... 评论

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Forensic Sciences Research 2018年第3期3卷 230-239页

作者： bernard van den Boom Cor j.Veenman Leiden University Leiden Institute of Advanced Computer Science(LIACS)LeidenThe Netherlands Netherlands Forensic Institute The HagueThe Netherlands TNO The HagueThe Netherlands

Law enforcement agencies have a restricted area in which their powers apply,which is called their *** restrictions also apply to the ***,on the Internet,the physical borders of the jurisdiction,typically country borders,are hard to *** our case,it is hard to establish whether someone involved in criminal online behavior is indeed a Dutch *** propose a way to overcome the arduous task of manually investigating whether a user on an Internet forum is Dutch or *** precisely,we aim to detect that a given English text is written by a Dutch native *** develop a detector,we follow a machine learning ***,we need to prepare a specific training *** obtain a corpus that is representative for online forums,we collected a large amount of English forum posts from Dutch and non-Dutch authors on *** learn a detection model,we used a bag-of-words representation to capture potential misspellings,grammatical errors or unusual turns of phrases that are characteristic of the mother tongue of the *** this learning task,we compare the linear support vector machine and regularized logistic regression using the appropriate performance metrics f1 score,precision,and average *** results show logistic regression with frequency-based feature selection performs best at predicting Dutch *** study should be directed to the general applicability of the results that is to find out if the developed models are applicable to other forums with comparable high performance.

关键词： Forensic data science text mining author profiling corpus creation big data open source intelligence native language verification

Interactive labelling of a multivariate dataset for supervised machine learning using linked visualisations,clustering,and active learning

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Visual Informatics 2019年第1期3卷 9-17页

作者： Mohammad Chegini jürgen bernard Philip Berger Alexei Sourin Keith Andrews Tobias Schreck Graz University of Technology Austria School of Computer Science and Engineering Nanyang Technological UniversitySingapore TU Darmstadt Germany University of Rostock Germany

Supervised machine learning techniques require labelled multivariate training *** approaches address the issue of unlabelled datasets by tightly coupling machine learning algorithms with interactive *** appropriate techniques,analysts can play an active role in a highly interactive and iterative machine learning process to label the dataset and create meaningful *** this principle has been implemented either for unsupervised,semi-supervised,or supervised machine learning tasks,the combination of all three methodologies remains *** this paper,a visual analytics approach is presented,combining a variety of machine learning capabilities with four linked visualisation views,all integrated within the mVis(multivariate Visualiser)*** available palette of techniques allows an analyst to perform exploratory data analysis on a multivariate dataset and divide it into meaningful labelled partitions,from which a classifier can be *** the workflow,the analyst can label interesting patterns or outliers in a semi-supervised process supported by active *** a dataset has been interactively labelled,the analyst can continue the workflow with supervised machine learning to assess to what degree the subsequent classifier has effectively learned the concepts expressed in the labelled training *** a novel technique called automatic dimension selection,interactions the analyst had with dimensions of the multivariate dataset are used to steer the machine learning algorithms.A real-world football dataset is used to show the utility of mVis for a series of analysis and labelling tasks,from initial labelling through iterations of data exploration,clustering,classification,and active learning to refine the named partitions,to finally producing a high-quality labelled training dataset suitable for training a *** tool empowers the analyst with interactive visualisations including scatterplots,parallel

关键词： Labelling Clustering Classification Active learning Multivariate data Visualisation