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Classification of Soil Types Using Geographic Object-Based Image Analysis and Random Forests

Pedosphere 2018年第6期28卷 913-925页

作者： andrei DORNIK Lucian DRAGUT Petru URDEA Department of Geography West University of Timioara

There is increasing interest in developing automatic procedures to segment landscapes into soil spatial entities that replace conventional, expensive manual procedures for delineating and classifying soils. Geographic object-based image analysis(GEOBIA)partitions remote sensing imagery or digital elevation models into homogeneous image objects based on image segmentation. We used an object-based methodology for the detailed delineation and classification of soil types using digital maps of topography and vegetation as soil covariates, based on the Random Forests(RF) classifier. We compared the object-based method's results with those of a pixel-based classification using the same classifier. We used 18 digital elevation model derivatives and 5 remote sensing indices that were related to vegetation cover and soil. Using 171 soil profiles with their associated environmental variable values,the RF method was used to identify the most important soil type predictors for use in the segmentation process. A stack of rastergeodatasets corresponding to the selected predictors was segmented using a multi-resolution segmentation algorithm, which resulted in homogeneous objects related to soil types. These objects were further classified as soil types using the same method, RF. We also conducted a pixel-based classification using the same classifier and soil profiles, and the resulting maps were assessed in terms of their accuracy using 30% of the soil profiles for validation. We found that GEOBIA was an effective method for soil type mapping, and was superior to the pixel-based approach. The optimized object-based soil map had an overall accuracy of 58%, which was 10% higher than that of the optimized pixel-based map.

关键词： GEOBIA landscape segmentation soil classification soil covariates soil mapping

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Heat Transfer in Internal Channel of a Blade:Effects of Rotation in a Trailing Edge Cooling System

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Journal of Thermal Science 2012年第3期21卷 236-249页

作者： Luca andrei Antonio andreini Leonardo Bonanni Bruno Facchini Department of Energy Engineering "Sergio Stecco" University of Florence

The aerothermal performance of a trailing edge （TE） internal cooling system of a high pressure gas turbine blade was evaluated under stationary and rotating conditions. The investigated geometry consists of a 30：1 scaled model reproducing a typical wedge shaped discharge duct with one row of enlarged pedestals. The airflow pattern inside the device simulates a highly loaded rotor blade cooling scheme with a 90 [deg] turning flow from the radial hub inlet to the tangential TE outlet. Two different tip configurations were tested, the first one with a completely closed section, the second one with a 5 holes outlet surfaces discharging at ambient pressure. In order to assess rotation effects, a rotating test rig, composed of a rotating ann holding both the PMMA TE model and the instru mentation, was purposely developed and manufactured. A thin Inconel heating foil and wide band Thermochromic Liquid Crystals are used to perform steady state heat transfer measurements on the blade pres sure side. A rotary joint ensures the pneumatic connection between the blower and the rotating apparatus; more over several slip rings are used for both instrumentation power supply and thermocouple connection. A parallel CFD analysis involving steadystate RANS modeling was conducted to allow an insight of the flow field inside the redirecting channel and the interpedestal ducts to better interpret the developing vortical structures. LowReynolds grid clustering permits to integrate up to the wall both the momentum and the thermal boundary layer. Calculations were performed by means of an inhouse developed pressure based solver exploiting the kco SST turbulence model implemented in the framework of the opensource finite volume discretization toolbox OpenFOAM~. Analyzed flow conditions correspond to Reynolds number of 20000 in the hub inlet section and angular speed varies to obtain rotation numbers in the range from 0 to 0.3. The orientation of the rotation axis is orthogonal to the heated s

关键词： heat transfer trailing edge pedestal rotation number OpenFOAM~ CFD TLC thermography

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Bi-normalized response spectra and seismic intensity in Bucharest for 1986 and 1990 Vrancea seismic events

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Earthquake Engineering and Engineering Vibration 2014年第1期13卷 125-135页

作者： Florin Pavel Radu Vacareanu Cristian Neagu andrei Pricopie Department of Reinforced Concrete Structures Technical University of Civil Engineering BucharestRomania Department of Strength of Materials Bridges and TunnelsTechnical University of Civil Engineering BucharestRomania

The Vrancea subcrustal earthquakes of August 30,1986 and May 30,1990 are the two most recent seismic events that have occurred in Romania with moment magnitudes M W ≥ *** spectral analysis of the strong ground motions recorded in Bucharest reveals that despite small differences in magnitude between the 1986 and 1990 earthquakes,their frequency contents are very different,sometimes even *** main focus of this study is to conduct a comparative analysis of the response spectra in terms of the bi-normalized response spectra(BNRS) proposed by Xu and Xie(2004 and 2007) for strong ground motions recorded in Bucharest during these two seismic *** mean absolute acceleration and relative velocity response spectra for the two earthquakes are discussed and ***,the mean bi-normalized absolute acceleration and normalized relative velocity response spectra with respect to the control period T C are computed for the ground motions recorded in Bucharest in 1986 and *** predominant period T P is also used in this study for the normalization of the spectral period ***,the methodology proposed by Martinez-Perreira and Bommer(1998) is applied in order to estimate the seismic intensity of the two *** results are discussed and several conclusions regarding the possibility of using the bi-normalized response spectra(BNRS) are given.

关键词： response spectra bi-normalized response spectra dynamic amplifi cation factor control period damage potential parameters

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On the Relationship Between the Baum-Katz-Spitzer Complete Convergence Theorem and the Law of the Iterated Logarithm

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Acta Mathematica Sinica,English Series 2007年第4期23卷 599-612页

作者： De Li LI Andrew ROSALSKY andrei VOLODIN Department o/Mathematical Sciences Lakehead University Thunder Bay ON Canada P7B 5E1 Department of Statistics University of Florida Gainesville FL 32611 USA Department of Mathematics and Statistics University of Regina Regina SK Canada S4S 0A2

For a sequence of i.i.d. Banach space-valued random variables {Xn; n ≥ 1} and a sequence of positive constants {an; n ≥ 1}, the relationship between the Baum-Katz-Spitzer complete convergence theorem and the law of the iterated logarithm is investigated. Sets of conditions are provided under which （i） lim sup n→∞ ｜｜Sn｜｜/an〈∞ *** ∞ ∑n=1（1/n）P（｜｜Sn｜｜/an ≥ε〈∞for all ε 〉 λ for some constant λ ∈ [0, ∞） are equivalent;（ii） For all constants λ ∈ [0, ∞）,lim sup ｜｜Sn｜｜/an =λ *** ^∞∑ n=1（1/n） P（｜｜Sn｜｜/an ≥ε）{〈∞, if ε〉λ =∞,if ε〈λare equivalent. In general, no geometric conditions are imposed on the underlying Banach space. Corollaries are presented and new results are obtained even in the case of real-valued random variables.

关键词： partial sums of i.i.d. Banach space-valued random variables Baum-Katz-Spitzer complete convergence theorem law of the iterated logarithm almost sure convergence

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Simulation modelling of potato virus Y spread in relation to initial inoculum and vector activity

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Journal of Integrative Agriculture 2020年第2期19卷 376-388页

作者： Andrew GALIMBERTI andrei ALYOKHIN Hongchun QU Jason ROSE School of Biology and Ecology University of MaineOronoME 04469USA Eastern New York Commercial Horticulture Program Cornell Cooperative ExtensionPlattsburghNY 12901USA College of Automation Chongqing University of Posts and TelecommunicationsChongqing 400065P.R.China

Potato virus Y(PVY)is a non-persistent virus that is transmitted by many aphid species and causes significant damage to potato *** constructed a spatially-explicit model simulating PVY spread in a potato field and used it to investigate possible effects of transmission efficiency,initial inoculum levels,vector behavior,vector abundance,and timing of peak vector activity on PVY incidence at the end of a simulated growing *** PVY incidence in planted seed resulted in lower virus infection at the end of the ***,when populations of efficient PVY vectors were high,significant PVY spread occurred even when initial virus inoculum was ***-colonizing aphids were more important for PVY spread compared to colonizing aphids,particularly at high *** early-season peak in the numbers of noncolonizing aphids resulted in the highest number of infected plants in the end of the season,while mid-and late-season peaks caused relatively little virus *** results highlight the importance of integrating different techniques to prevent the number of PVY-infected plants from exceeding economically acceptable levels instead of trying to control aphids within potato *** management plans should be implemented very early in a growing season.

关键词： potato virus Y spatially-explicit modelling aphids virus spread integrated pest management

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A necessary and sufficient condition for a surface sum of two handlebodies to be a handlebody

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Science China Mathematics 2020年第10期63卷 1997-2004页

作者： Fengchun Lei He Liu Fengling Li andrei Vesnin School of Mathematical Sciences Dalian University of TechnologyDalian 116024China Regional Scientific and Educational Mathematical Center Department of Mechanics and MathematicsTomsk State UniversityTomsk 634050Russia

The main results of the paper are that we give a necessary and sufficient condition for a surface sum of two handlebodies along a connected surface to be a handlebody as follows:(1)The annulus sum H=H1∪AH2 of two handlebodies H1 and H2 is a handlebody if and only if the core curve of A is a longitude for either H1 or H2;(2)Let H=H1∪Sg,b H2 be a surface sum of two handlebodies H1 and H2 along a connected surface S=Sg,b,b 1,ni=g(Hi)2,i=1,*** that S is incompressible in both H1 and *** H is a handlebody if and only if there exists a basis J={J1,...,Jm}with a partition(J1,J2)of J such that J1 is primitive in H1 and J2 is primitive in H2.

关键词： handlebody surface sum of 3-manifolds free group

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Life-Cycle and Seismic Fragility Assessment of Code-Conforming Reinforced Concrete and Steel Structures in Bucharest, Romania

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International Journal of Disaster Risk Science 2018年第2期9卷 263-274页

作者： Florin Pavel Ileana Calotescu Dan Stanescu andrei Badiu Technical University of Civil Engineering Bucharest

In this article, the fragility of reinforced concrete and steel structures in Bucharest, a city of high seismic hazard, designed using the recent building codes in Romania, is assessed. A total of 24 reinforced concrete and steel structures with heights varying from five stories to 13 stories were analyzed. Their seismic fragility was evaluated using two procedures from the literature. In the first procedure(SPO2 FRAG), the fragility was derived based on the pushover curves using the SPO2 IDA algorithm, while in the second procedure(FRACAS), the fragility was derived from nonlinear time-history analyses. The analyzed structures were designed for three levels of peak ground accelerations, corresponding to mean return periods of 100,225, and 475 years. Subsequently, the damage assessment of the analyzed structures was performed using ground motions generated from a Monte-Carlo simulated earthquake catalogue for the Vrancea intermediate-depth seismic source. The damage degrees that were estimated using the SPO2 FRAG approach are higher than those estimated using the FRACAS approach. The life-cycle analysis of the structures shows that a further increase of the design peak ground acceleration for Bucharest is feasible from an economic point of view using the SPO2 FRAG ***, based on the FRACAS results, the opposite conclusion can be drawn. Finally, generic lognormal fragility functions are proposed as a function of building height and structural system.

关键词： Bucharest Building damage degree Building life-cycle analysis Monte-Carlo simulated earthquake catalogue Seismic risk Vrancea seismic source

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Body Building on Diamonds

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Journal of Bionic Engineering 2009年第1期6卷 14-17页

作者： andrei P. Sommer Tim Scharnweber Hans-Joerg Fecht Institute of Micro and Nanomaterials University of UlmUlm 89081Germany Institute for Biological Interfaces Research Center KarlsruheKarlsruhe 76021Germany Institute for Nanotechnology Research Center Karlsruhe Karlsruhe 76021Germany

Whereas conservative therapies aim to stall the advance of disease,regenerative medicine strives to reverse *** capacity of most tissues to regenerate derives from stem cells,but there are a number of barriers which have to be circumvented before it will be possible to use stem-cell-based *** therapies,however,are expected to improve human health enormously, and knowledge gained from studying stem cells in culture and in model organisms is now laying the groundwork for a new era of regenerative *** of the most prominent methods to study stem cell differentiation is to let them to form embryoid *** favourable conditions any stem cell line will form embryoid ***,the mechanism of the formation of embryoid bodies is not very well understood,and to produce them in the laboratory is in no way trivial-an important technical barrier in stem cell ***,the embryoid body cultivation step has been successfully circumvented for the derivation of osteogenic cultures of embryonic stem *** we report on a simple and reusable system to cultivate embryoid bodies in extremely short *** method is inspired by the principles that lead to the establishment of the biomimetic triangle.

关键词： biomimetic triangle stem cells embryoid bodies nanobionics nanocrystalline diamond

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Introspection on improper seismic retrofit of Basilica Santa Maria di Collemaggio after 2009 Italian earthquake

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Earthquake Engineering and Engineering Vibration 2011年第1期10卷 153-161页

作者： Gian Paolo Cimellaro andrei M. Reinhorn Alessandro De Stefano Department of Structural & Geotechnical Engineering (DISTR) Politecnico di Torino Department of Civil Structural & Environmental Engineering University at Buffalo The State University of New York

The 2009 L’Aquila, Italy earthquake highlighted the seismic vulnerability of historic masonry building structures due to improper ＂strengthening＂ retrofit work that has been done in the last 50 years. Italian seismic standards recommend the use of traditional reinforcement techniques such as replacing the original wooden roof structure with new reinforced concrete （RC） or steel elements, inserting RC tie-beams in the masonry and new RC floors, and using RC jacketing on the shear walls. The L’Aquila earthquake revealed the numerous limitations of these interventions, because they led to increased seismic forces （due to greater additional weight） and to deformation incompatibilities of the incorporated elements with the existing masonry walls. This paper provides a discussion of technical issues pertaining to the seismic retrofit of the Santa Maria di Collemaggio Basilica and in particular, the limitations of the last （2000） retrofit intervention. Considerable damage was caused to the church because of questionable actions and incorrect and improper technical choices.

关键词： seismic vulnerability historic masonry building wooden roof structure seismic retrofit L’Aquila earthquake

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Analytical Modelling of Fuel Cells Har/Cdr

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2010年

作者： andrei A. Kulikovsky

ISBN: (数字)9780444535610

ISBN: (纸本)9780444535603

In fuel cell research, the gap between fundamental electrochemical processes and the engineering of fuel cell systems is bridged by the physical modelling of fuel cells. This relatively new discipline aims to understand the basic transport and kinetic phenomena in a real cell and stack environment, paving the way for improved design and performance. The author brings his unique approach to the analytical modeling of fuel cells to this essential reference for energy technologists.

关键词： Fuel cellsMathematical models.

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