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Modeling constitutive relationship of 6013 aluminum alloy during hot plane strain compression based on kriging method

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Transactions of Nonferrous Metals Society of China 2016年第4期26卷 1096-1104页

作者：肖罡杨钦文李落星湖南大学汽车车身先进设计制造国家重点实验室长沙410082 湖南大学机械与运载工程学院长沙410082

Hot plane strain compression tests of 6013 aluminum alloy were conducted within the temperature range of 613?773 K and the strain rate range of 0.001?10 s?1. Based on the corrected experimental data with temperature compensation, kriging method is selected to model the constitutive relationship among flow stress, temperature, strain rate and strain. The predictability and reliability of the constructed kriging model are evaluated by statistical measures, comparative analysis and leave-one-out cross-validation (LOO-CV). The accuracy of kriging model is validated by the R-value of 0.999 and the AARE of 0.478%. Meanwhile, its superiority has been demonstrated while comparing with the improved Arrhenius-type model. Furthermore, the generalization capability of kriging model is identified by LOO-CV with 25 times of testing. It is indicated that kriging method is competent to develop accurate model for describing the hot deformation behavior and predicting the flow stress even beyond the experimental conditions in hot compression tests.

关键词： aluminum alloy hot deformation constitutive model kriging method

Using Remote Sensing Data to Delineate the Lineaments for Hydrothermal Mineral Prediction in Heqing Area, Northwest Yunnan Province, China

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Journal of China University of Geosciences 2007年第2期18卷 142-147页

作者： Mansour S Al-Mokredi 胡光道 Bassam F Al Bassam Faculty of Earth Resources China University of Geosciences

Lineament extraction and analysis is one of the routine work in mapping medium and large areas using remote sensing data, most of which are satellite images. Landsat Enhanced Thematic Mapper （ETM） of 945×1 232 pixels subscene acquired on 21 March 2000 covering the northwestern part of Yunnan Province has been digitally processed using ER Mapper software. This article aims to produce lineament density map that predicts favorable zones for hydrothermal mineral occurrences and quantify spatial associations between the known hydrothermal mineral deposits. In the process of lineament extraction a number of image processing techniques were applied. The extracted lineaments were imported into MapGIS software and a suitable grid of 100 m×100 m was chosen. The kriging method was used to create the lineament density map of the area. The results show that remote sensing data could be useful to extract the lineaments in the area. These lineaments are closely correlated with the faults obtained through other geological investigation methods. On comparing with field data the lineament-density map identifies two important high prospective zones, where large-scale deposits are already existing. In addition the map highlights unrecognized target areas that require follow up investigation.

关键词： lineament extraction hydrothermal mineral prediction kriging method Heqing area(China)

Water content distribution in the surface layer of Maoping slope

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Science China(Technological Sciences) 2005年第Z1期48卷 157-170页

作者： LIU Yuewu CHEN Huixin LIU Qingquan GONG Xin ZHANG Dawei LI Lianxiang Division of Engineering Science Institute of MechanicsChinese Academy of SciencesBeijing 100080China

The water content distribution in the surface layer of Maoping slope has been studied by testing the water content at 31 control *** water content profiles at these sites have also been *** water content distributions at different segments have been obtained by using the kriging method of *** comparing the water content distributions with the landform of the slope,it was shown that the water content is closely dependent on the landform of the *** water content distribution in the surface layer provided a fundamental basis for landslide predication and treatment.

关键词： landslide water content in situ test kriging method geostatistics.

Distribution of Extracellular Polymeric Substances in Pilot-Scale Membrane Bioreactor

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Transactions of Tianjin University 2010年第2期16卷 147-151页

作者：邢锴张宏伟沙之杰牛志广李莹王亮 School of Environmental Science and Engineering Tianjin University Southwestern University of Finance and Economy Department of Environmental Engineering Tianjin Polytechnic University

The spatial distribution of extracellular polymeric substances （EPS） in a pilot-scale membrane bioreactor （MBR） was studied. The sampling points on top of and inside the membrane module were measured and analyzed by the experimental variant function. The content of EPS was spatially interpolated by ordinary kriging method, and il- lustrated with SURFER software. A case study was carried out in an MBR with membrane aperture of 0.4 ~tm and handling capacity of 120 ma/d in Jizhuangzi sewage treatment plant, Tianjin. From the visualization of EPS distribu- tion, it is seen that on the horizontal plane, the content of EPS was the lowest at the center; and on the vertical plane, the content of EPS decreased with the increase of depth. The shearing force caused by aeration of perforated pipe and the influent mode are the main influencing factors for this distribution.

关键词： MBR EPS kriging method distribution

Mapping runoff based on hydro-stochastic approach for the Huaihe River Basin, China

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Journal of Geographical Sciences 2011年第3期21卷 441-457页

作者： YAN Ziqi XIA Jun Lars GOTTSCHALK Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Department of Geosciences University of Oslo N-0315 Oslo Norway

Theoretical difficulties for mapping and for estimating river regime characteristics in a large-scale basin remain because of the nature of the variable under study： river flows are related to a specific area, i.e. the drainage basin, and are hierarchically organized in space through the river network with upstream-downstream dependencies. Another limitation is there are not enough gauge stations in developing countries. This presentation aims at developing the hydro-stochastic approach for producing choropleth maps of average annual runoff and computing mean discharge along the main river network for a large-scale basin. The approach applied to mean annual runoff is based on geostatistical interpolation proce- dures coupled with water balance and data uncertainty analyses. It is proved by an applica- tion in the upstream at Bengbu in the Huaihe River Basin, a typical large-scale basin in China. Hydro-stochasitic approach in a first step interpolates to a regular grid net and in a second step the grid values are integrated along rivers, The interpolation scheme includes a constraint to be able to account for the lateral water balance along the rivers. Grid runoff map with 10 km x 10 km resolution and the discharge map along the river with the 1 km basic length unit are the main results in this study. This kind of statistic approach can be widely used because it avoids the complexity of hydrological models and does not depend on the meteorological data.

关键词： kriging method hydro-stochastic runoff water balance Huaihe River Basin

Prediction of Aircraft＇s Longitudinal Motion Based on Aerodynamic Coefficients and Derivatives by Surrogate Model Approach

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Journal of Mechanics Engineering and Automation 2014年第7期4卷 584-594页

作者： Norazila Othman Masahiro Kanazaki Graduate School of System Design Division of Aerospace Engineering Tokyo Metropolitan University Hino City 191-0065 Japan

The accuracy of a flight simulation is highly dependent on the quality of the aerodynamic database and prediction accuracies of the aerodynamic coefficients and derivatives. A surrogate model is an approximation method that is used to predict unknown functions based on the sampling data obtained by the design of experiments. This model can also be used to predict aerodynamic coefficients/derivatives using several measured points. The objective of this paper is to develop an efficient digital flight simulation by solving the equation of motion to predict the aerodynamics data using a surrogate model. Accordingly, there is a need to construct and investigate aerodynamic databases and compare the accuracy of the surrogate model with the exact solution, and hence solve the equation of motion for the flight simulation analysis. In this study, sample datas for models are acquired from the USAF Stability and Control DATCOM, and a database is constructed for two input variables （the angle of attack and Mach number）, along with two derivatives of the X-force axis and three derivatives for the Z-force axis and pitching moment. Furthermore, a comparison of the value predicted by the kriging model and the exact solution shows that its flight analysis prediction ability makes it possible to use the surrogate model in future analyses.

关键词： Surrogate model kriging method equation of motion standard dynamics model.