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Terrain based co-operative UAV mapping of complex obstacles using 2-D splinegon

International Journal of Intelligent Computing and Cybernetics 2012年第3期5卷 248-292页

作者： samuel b.lazarus Antonios Tsourdos brian A.White Peter Silson Al Savvaris Camille-Alain Rabbath Nicolas Lèchevin School of Engineering Cranfield UniversityCranfieldUK Autonomous Systems Group Defence Academy of the United KingdomCranfield UniversityShrivenhamUK Defence Research and Development Canada-Valcartier Quebec CityCanada Numerica Technologies Inc.ValcartierQuebec CityCanada

Purpose-This paper aims to describe a recently proposed algorithm in terrain-based cooperative UAV mapping of the unknown complex obstacle in a stationary environment where the complex obstacles are represented as curved in *** also aims to use an extended Kalman filter(EKF)to estimate the fused position of the UAVs and to apply the 2-D splinegon technique to build the map of the complex shaped *** path of the UAVs are dictated by the Dubins path planning *** focus is to achieve a guaranteed performance of sensor based mapping of the uncertain environments using multiple ***/methodology/approach–An extended Kalman filter is used to estimate the position of the UAVs,and the 2-D splinegon technique is used to build the map of the complex obstacle where the path of the UAVs are dictated by the Dubins path planning ***-The guaranteed performance is quantified by explicit bounds of the position estimate of the multiple UAVs for mapping of the complex obstacles using 2-D splinegon *** is a newly proposed algorithm,the most efficient and a robust way in terrain based mapping of the complex *** proposed method can provide mathematically provable and performance guarantees that are achievable in ***/value-The paper describes the main contribution in mapping the complex shaped curvilinear objects using the 2-D splinegon *** is a new approach where the fused EKF estimated positions are used with the limited number of sensors’measurements in building the map of the complex obstacles.

关键词： Multiple sensor fusion Data fusion EKF based navigation Multiple UAVs 2-D splinegon Robust UAV localization Complex obstacle mapping Sensor fusion Navigation

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Effects of Navier slip on unsteady flow of a reactive variable viscosity non-Newtonian fluid through a porous saturated medium with asymmetric convective boundary conditions

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Journal of Hydrodynamics 2015年第6期27卷 934-944页

作者： RUNDORA lazarus MAKINDE Oluwole Daniel Department of Mathematics and Applied Mathematics University of LimpopoTurfloop Campus Faculty of Military Science Stellenbosch University

A study on the effects of Navier slip, in conjunction with other flow parameters, on unsteady flow of reactive variable viscosity third-grade fluid through a porous saturated medium with asymmetric convective boundary conditions is presented. The channel walls are assumed to be subjected to asymmetric convective heat exchange with the ambient, and exothermic chemical reactions take place within the flow system. The heat exchange with the ambient obeys Newton＇s law of cooling. The coupled equations, arising from the law of conservation of momentum and the first law of thermodynamics, then the derived system are non- dimensionalised and solved using a semi-implicit finite difference scheme. The lower wall slip parameter is observed to increase the fluid velocity profiles, whereas the upper wall slip parameter retards them because of backflow at the upper channel wall. Heat pro- duction in the fluid is seen to increase with the slip parameters. The wall shear stress increases with the slip parameters while the wall heat transfer rate is largely unaltered by the lower wall slip parameter but marginally increased by the upper wall slip parameter.

关键词： Navier slip saturated porous medium third-grade fluid temperature dependent viscosity convective boundary condi-tions

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Corrosion rate determination of rare-earth Mg alloys in a Na_(2)SO_(4)solution by electrochemical measurements and inductive coupled plasma-optical emission spectroscopy

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Journal of Magnesium and Alloys 2019年第1期7卷 47-57页

作者： samuel Leleu bertrand Rives Nicolas Causse Nadine Pébère CIRIMAT Universitéde ToulouseCNRSINPTUPSENSIACET4 allée Emile Monso BP4436231030 Toulouse cedex 4 France IRT Saint Exupéry 118 route de Narbonne-CS 4424831432 ToulouseFrance

The corrosion resistance of three Mg alloys containing rare-earth elements(WE43,EV31 and ZE41)was studied and compared to that of two Mg-Al alloys(AZ31 and AZ91)and of pure Mg(99.95 wt.%).Current-voltage curves and electrochemical impedance measurements were performed with rotating disk electrodes in an aerated 0.1 M Na_(2)SO_(4)*** all the alloys,it was confirmed that the intermetallic particles acted as local cathodes and that more protective films were formed on the alloys surface by comparison with the pure *** rates were determined from inductive coupled plasma-optical emission spectroscopy measurements and from the electrochemical *** corrosion rates were observed for the rare-earth Mg alloys compared to the AZ series *** data allowed the corrosion mechanisms to be discussed.

关键词： Magnesium alloys Rare-earth elements EIS ICP-OES Interface

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Analytical modeling and simulation of germanium single gate silicon on insulator TFET

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Journal of Semiconductors 2014年第3期35卷 25-28页

作者： T.S.Arun samuel N.b.balamurugan Department of Electronics and Communication Engineering Thiagarajar College of Engineering

This paper proposes a new two dimensional（2D） analytical model for a germanium（Ge） single gate silicon-on-insulator tunnel field effect transistor（SG SOI TFET）. The parabolic approximation technique is used to solve the 2D Poisson equation with suitable boundary conditions and analytical expressions are derived for the surfacepotential,*** is derived further by using the electric fields. The results show that Ge based TFETs have significant improvements ***heanalytical model results with the technology computer aided design（TCAD） simulation results and also comparing them with results from a silicon based TFET.

关键词： tunnel field effect transistor(TFET) analytical modelling Poisson equation surface potential electric field

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Disagreement between symptom-reflux association analysis parameters in pediatric gastroesophageal reflux disease investigation

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World Journal of Gastroenterology 2010年第19期16卷 2401-2406页

作者： samuel C Lüthold Mascha K Rochat Peter bhler Division of Gastroenterology Departement of Pediatrics Hospital of Fribourg CH-1708 Fribourg Switzerland Asthma and Allergy Research Group University of Munich Lindwurmstrasse 4 D 80337 Munich Germany

AIM: To assess the agreement within 3 commonly used symptom-reflux association analysis (SAA) parameters investigating gastroesophageal reflux disease (GERD) in infants. METHODS: Twenty three infants with suspected GERD were included in this study. Symptom index (SI), Symptom sensitivity index (SSI) and symptom association probability (SAP) related to cough and irritability were calculated after 24 h combined pH/multiple intraluminal impedance (MII) monitoring. Through defined cutoff values, SI, SSI and SAP values are differentiated in normal and abnormal, whereas abnormal values point towards gastroesophageal reflux (GER) as the origin of symptoms. We analyzed the correlation and the concordance of the diagnostic classification of these 3 SAA ***: Evaluating the GER-irritability association, SI, SSI and SAP showed non-identical classification of normal and abnormal cases in 39.2% of the infants. When irritability was taken as a symptom, there was only a poor inter-parameter association between SI and SSI, and between SI and SAP (Kendall’s tau b = 0.37, P b = 0.36, P bnormal cases in 52.2% of the patients. When cough was taken as a symptom, only SI and SSI showed a poor inter-parameter association (Kendall’s tau b = 0.33, P be taken into consideration when interpreting the results of SAA in infants.

关键词： Gastroesophageal reflux disease Infant Symptom-reflux association analysis Intraluminal impedance monitoring pH

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Extracellular matrices, artificial neural scaffolds and the promise of neural regeneration

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Neural Regeneration Research 2014年第17期9卷 1573-1577页

作者： Christian b.Ricks samuel S.Shin Christopher becker Ramesh Grandhi Department of Neurological Surgery University of Pittsburgh Medical CenterPittsburghPAUSA University of Pittsburgh School of Medicine PittsburghPAUSA

Over last 20 years, extracellular matrices have been shown to be useful in promoting tissue regeneration. Recently, they have been used and have had success in achieving neurogenesis. Recent developments in extracellular matrix design have allowed their successful in vivo incorporation to engender an environment favorable for neural regeneration in animal models. Promising treatments under investigation include manipulation of the intrinsic extracellular matrix and incorporation of engineered naometer-sized scaffolds through which inhibition of molecules serving as barriers to neuroregeneration and delivery of neurotrophic factors and/or cells for successful tissue regeneration can be achieved. Further understanding of the changes incurred within the extracellular matrix following central nervous system injury will undoubtedly help design a clinically efficacious extracellular matrix scaffold that can mitigate or reverse neural degeneration in the clinical setting.

关键词： extraceUular matrix neurogenesis scaffolds neural stem cells

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Flow, thermal criticality and transition of a reactive third-grade fluid in a pipe with Reynolds' model viscosity

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Journal of Hydrodynamics 2016年第1期28卷 84-94页

作者： samuel S.OKOYA Department of Mathematics Obafemi Awolowo University

Neglecting the consumption of the material, a steady incompressible flow of an exothermic reacting third-grade fluid with viscous heating in a circular cylindrical pipe is numerically studied for both cases of constant viscosity and Reynolds＇ viscosity model. The coupled ordinary differential equations governing the flow in cylindrical coordinates, are transformed into dimensionless forms using appropriate transformations, and then solved numerically. Solutions using Maple are presented in tabular form and given in terms of dimensionless central fluid velocity and temperature, skin friction and heat transfer rate for three parametric values in the Reynolds＇ case. The numerical results for the velocity and temperature fields are also presented through graphs. bifurcations are discussed using shooting method. Comparisons are also made between the present results and those of previous work, and thus verify the validity of the provided numerical solutions. Important properties of thermal criticality are provided for variable viscosity parameter and reaction order. Further numerical results are presented in the form of tables and graphs for transition of physical parameters, while varying certain flow and fluid material parameters. Also, the flow behaviour of the reactive fluid of third-grade is compared with those of the Newtonian reactive fluid.

关键词： non-Newtonian fluids third-grade fluid thermal transition heat generation temperature dependent viscosity numerical solutions

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Wildfire and floral herbivory alter reproduction and pollinator mutualisms of Yuccas and Yucca moths

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Journal of Plant Ecology 2017年第5期10卷 851-858页

作者： Andrew H.Lybbert samuel b.St.Clair Department of Evolution Ecology and Organismal BiologyThe Ohio State UniversityColumbusOH 43210USA Department of Plant and Wildlife Sciences Brigham Young UniversityProvoUT 84602USA

Aims Wildfire and ungulate herbivore pressure are increasing globally due to human activities,including arid ecosystems that are sensitive to disturbance,and are highly dependent on pollinator *** evaluated how wildfire and ungulate herbivore pressure influ-ence plant reproductive success and pollinator *** We evaluated flower production,floral herbivory,pollinator visita-tion and fruit set of two Yucca species with highly specialized polli-nator mutualisms(Yucca baccata and Yucca brevifolia)in unburned and burned landscapes created by fires that occurred in the Mojave Desert in *** Findings Yucca baccata plants in burned landscapes had a greater propor-tion of flowering individuals than plants in unburned areas(23 versus 12%).All *** individuals in burned and unburned landscapes produced ***-four percent of *** inflorescences were removed due to herbivory by cattle in burned areas,compared to 51%in unburned ***-two percent of *** inflorescences on branches≤2 m in height were removed in burned areas due to cattle herbivory compared to 39%in unburned ***,we did not observe any inflores-cence removal on *** branches>2 m where the major-ity of *** inflorescences are *** moths,the only known pollinators of these two species,visited *** uniformly in burned and unburned areas but failed to visit ***-cata *** brevifolia had strong fruit production,but not a single fruit was produced among the thousands of flowering *** plants *** herbivory and the loss of obligate pollinator mutualisms appear to be critical threats to the long-term viability of *** populations in this *** reproduc-tive resilience of *** and the maintenance of its pollinator populations appear to be due to its taller stature,which allows verti-cal escape of flowers from ungulate *** of live-stock during

关键词： cattle disturbance Mojave Desert pollination Yucca brevifolia Yucca baccata

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Single-model uncertainty quantification in neural network potentials does not consistently outperform model ensembles

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npj Computational Materials 2023年第1期9卷 49-59页

作者： Aik Rui Tan Shingo Urata samuel Goldman Johannes C.b.Dietschreit Rafael Gómez-bombarelli Department of Materials Science and Engineering Massachusetts Institute of TechnologyCambridgeMAUSA Innovative Technology Laboratories AGC IncTokyoJapan Computational and Systems biology Massachusetts Institute of TechnologyCambridgeMAUSA

Neural networks(NNs)often assign high confidence to their predictions,even for points far out of distribution,making uncertainty quantification(UQ)a *** they are employed to model interatomic potentials in materials systems,this problem leads to unphysical structures that disrupt simulations,or to biased statistics and dynamics that do not reflect the true *** UQ techniques can find new informative data and drive active learning loops for robust ***,a variety of UQ techniques,including newly developed ones,exist for atomistic simulations and there are no clear guidelines for which are most effective or suitable for a given *** this work,we examine multiple UQ schemes for improving the robustness of NN interatomic potentials(NNIPs)through active *** particular,we compare incumbent ensemble-based methods against strategies that use single,deterministic NNs:mean-variance estimation(MVE),deep evidential regression,and Gaussian mixture models(GMM).We explore three datasets ranging from in-domain interpolative learning to more extrapolative out-of-domain generalization challenges:rMD17,ammonia inversion,and bulk silica *** is measured across multiple metrics relating model error to *** experiments show that none of the methods consistently outperformed each other across the various *** remained better at generalization and for NNIP robustness;MVE only proved effective for in-domain interpolation,while GMM was better out-of-domain;and evidential regression,despite its promise,was not the preferable alternative in any of the *** broadly,cost-effective,single deterministic models cannot yet consistently match or outperform ensembling for uncertainty quantification in NNIPs.

关键词： ensemble evident neural

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bacteriophages Isolated in China for the Control of Pectobacterium carotovorum Causing Potato Soft Rot in Kenya

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Virologica Sinica 2019年第3期34卷 287-294页

作者： Peter Muturi Junping Yu Alice Nyambura Maina samuel Kariuki Frantis b.Mwaura Hongping Wei Key Laboratory of Emerging Pathogens and biosafety Wuhan Institute of VirologyChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China Centre for Microbiology Research Kenya Medical Research InstituteNairobi 00202Kenya School of biological and Life Sciences Technical University of KenyaNairobi 00200Kenya School of biological Sciences University of NairobiNairobi 00100Kenya Sino-Africa Joint Research Centre Nairobi 00200Kenya

Soft rot is an economically significant disease in potato and one of the major threats to sustainable potato *** study aimed at isolating lytic bacteriophages and evaluating methods for and the efficacy of applying phages to control potato soft rot caused by Pectobacterium *** bacteriophages isolated from soil and water samples collected in Wuhan,China,were used to infect *** host strains isolated from potato tubers showing soft rot symptoms in Nakuru county,*** efficacy of the phages in controlling soft rot disease was evaluated by applying individual phage strains or a phage cocktail on potato slices and tubers at different time points before or after inoculation with a *** *** phages could lyse 20 strains of ***,but not Pseudomonas fluorescens control *** the 11 phages,Pectobacterium phage Wc5r,interestingly showed cross-activity against Pectobacterium atrosepticum and two phage-resistant *** *** slice assays showed that the phage concentration and timing of application are crucial factors for effective soft rot *** cocktail applied at a concentration of 1×10^9 plaque-forming units per milliliter before or within an hour after bacterial inoculation on potato slices,resulted in>90%reduction of soft rot *** study provides a basis for the development and application of phages to reduce the impact of potato soft rot disease.

关键词： Pectobacterium carotovorum Potato soft rot bacteriophages Phage resistance

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