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Global operational land imager Landsat-8 reflectance-based active fire detection algorithm

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International Journal of digital Earth 2018年第2期11卷 154-178页

作者： S.S.Kumar d.p.roy plant and Environmental Sciences New Mexico State UniversityLas CrucesNMUSA Geospatial Sciences Center of Excellence South Dakota State UniversityBrookingsSDUSA

A global operational land imager(GOLI)Landsat-8 daytime active fire detection algorithm is *** utilizes established contextual active fire detection approaches but takes advantage of the significant increase in fire reflectance in Landsat-8 band 7(2.20μm)relative to band 4(0.66μm).The detection thresholds are fixed and based on a statistical examination of 39 million non-burning Landsat-8 ***-temporal tests based on band 7 reflectance and relative changes in normalized difference vegetation index in the previous six months are used to reduce commissions *** probabilities of active fire detection for the GOLI and two recent Landsat-8 active fire detection algorithms are simulated to provide insights into their performance with respect to the fire size and *** algorithms are applied to 11 Landsat-8 images that encompass a range of burning conditions and *** and omission errors are assessed by visual interpretation of detected active fire locations and by examination of the Landsat-8 images and higher spatial resolution Google Earth *** GOLI algorithm has lower omission and comparable commission errors than the recent Landsat-8 active fire detection *** GOLI algorithm has demonstrable potential for global application and is suitable for implementation with other Landsat-like reflective wavelength sensors.

关键词： Earth observation remote sensing visible/infrared remote sensing

Vibration of an infinite inhomogeneous transversely isotropic viscoelastic medium with cylindrical hole

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Applied Mathematics and Mechanics(English Edition) 2008年第3期29卷 367-378页

作者： d.p.Acharya Indrajit roy p.K.Biswas 109/3 Kailash Roy Chowdhury RoadBarrackporeKolkata 700120WBIndia Brahmapara SimuraliNadia 741248WBIndia department of Mathematics Kanchrapara CollegeKanchraparaWBIndia

This paper investigates the influences of higher order viscoelasticity and the inhomogeneities of the transversely isotropic elastic parameters on the disturbances in an infinite medium, caused by the presence of a transient radial force or twist on the surface of a cylindrical hole with circular cross section. Following Voigt＇s model for higher order viscoelasticity, the nonvanishing stress components valid for a transversely isotropic and higher order viscoelastic solid medium have been deduced in terms of radial displacement component. Considering the power law variation of elastic and viscoelastic parameters, the stress equation of motion has been developed. Solving this equation under suitable boundary conditions, due to transient forces and twists, radial displacement and relevant stress components have been determined in terms of modified Bessel functions. The problem for the presence of transient radial force has been numerically analysed. Modulations of displacement and stresses due to different order of viscoelasticity and inhomogeneity have been graphically depicted. The numerical study of the disturbance caused by the presence of twist on the surface may be similarly done but is not pursued in this paper.

关键词： higher order viscoelasticity inhomogeneity and transversely isotropy transient force and twist radial displacement stress components modified Bessel functions

Bacteriological challenges to asbestos cement water distribution pipelines

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Journal of Environmental Sciences 2010年第8期22卷 1203-1208页

作者： dunling Wang d. roy Cullimore Centre for Sustainable Infrastructure Research Institute for Research in Construction National Research Council Canada 6 Research Drive Regina SK S4S 7J7 Canada droycon Bioconcepts Inc. 315 Dewdney Avenue Regina SK S4N 0E7 Canada

Asbestos cement （AC） pipes were commonly installed in the drinking water distribution systems from the mid 1920s to the late 1980s. In recent years, an increase in the number of water main breaks has occurred in the AC portions of some pipe networks, which can be partially attributed to the corrosion of the aged pipes. This study evaluated the potential role that microorganisms may have played in the degeneration and failure of AC pipes. In this study, a fresh AC pipe section was collected from the distribution network of the City of Regina, Canada and examined for microbiological activities and growth on inside surfaces of pipe sample. Black slime bacterial growths were found to be attached to inner pipe surfaces and a distinctively fibrous internal coating （patina） with iron oxides was formed over the time. The microbial populations inside the patina and the black slime were tested with BART^TM testers. Heterotrophic aerobic bacteria （HAB） and slime forming bacteria （SLYM） dominated in both the black growths and inside the patina. Iron related bacteria, denitrification bacteria and sulfate reducing bacteria were also commonly present. Microbial challenge assays were conducted by submerging the cut segments of the AC pipe into selected bacterial cultures for a period of 10 days under both aerobic and anaerobic environments. Weight changes were determined and the surface morphology was examined for each of the assayed pipe segments. Results indicated that acid producing bacteria, SLYM and HAB could facilitate the pipe weight loss under anaerobic environments.

关键词： asbestos cement pipes drinking water distribution network bacteriological challenges biofilms patina

Effect of natural and synthetic antioxidants on oxidative stability of FAMEs obtained from hevea brasiliensis

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Journal of Energy Chemistry 2013年第6期22卷 935-941页

作者： S.Nivetha d.Vetha roy department of Chemistry and Research Centre Scott Christian College

Biodiesel(fatty acid alkyl esters),an alternate to fossil fuel,has the tendency of autoxidation and hence requires antioxidants for long term *** influence of synthetic and natural antioxidants on the oxidative stability was analysed for fresh FAMEs(fatty acid methyl esters)obtained from hevea brasiliensis at 140 *** activity was observed for synthetic antioxidants following the order of GA>BHT>dTBp>Q>GT-M>pH-M>GT-C,whereas the oxidative stability of stored FAMEs samples measured at 110 C reveals a nearly inverse *** stability was tested for the FAMEs obtained from hevea brasiliensis stored at 30 C,after addition of synthetic and natural antioxidants—butylated hydroxytoluene(BHT),2,6-di-tert-butylphenol(dTBp),quercetin(Q),gallic acid(GA),methanol extracts from green tea(GTM),pomegranate hull(pH-M),and chloroform extract of green tea(GT-C).Antioxidant activities above 1500 ppm was in the order of dTBp>BHT>GA>GT-C>GT-M>Q>*** antioxidants have been found more efficient to improve the storage stability of FAMEs obtained from hevea *** in particular has the highest protection factor.

关键词： hevea brasiliensis fatty acid methyl esters oxidative stability storage stability antioxidants

design and simulation of optoelectronic oscillator with micro ring resonator and radio frequency amplifier modelling at 110 GHz

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Optoelectronics Letters 2021年第8期17卷 482-489页

作者： Anil Kurian p Ugra Mohan roy department of Electronics and Communication Engineering Ramaiah University of Applied SciencesBangalore 560034India

There is an increasing need for high performance oscillators as the faster transmission networks demand for high frequency ***-electronic oscillators(OEO)enable us to make better oscillators in terms of size,weight and *** this paper,photonic integration is proposed for realizing the OEO with micro ring resonator(MRR)and radio-frequency(RF)amplifiers of monolithic microwave integrated circuit(MMIC),which can be used for generating 110 GHz sine *** OEO architecture is proposed and block diagram developed considering Silicon based MRR and three-stage RF amplifier based on Ga N high-electron-mobility transistor(HEMT).A simulation model is developed according to the Klein model of MRR and is validated against the calculated performance *** dimensions are calculated as with silicon on insulator(SOI)technology and a radius 5.27μm for the device is *** spectral range(FSR)of 48.52 nm and filter rejection ratio of 16.79 d B are obtained for this *** proposed RF amplifier is modelled with Ga N parameters derived from high frequency pinch-off model and with power amplifier *** gain for this amplifier is obtained as 10.6 d *** OEO design is developed in this project in such a way that the system can be manufactured with the existing methods.

关键词： amplifier resonator optoelectronic

A simple approach for stability margin of discrete systems

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控制理论与应用（英文版） 2011年第4期9卷 567-570页

作者： Yogesh V. HOTE J. R. p. GUpTA d. roy CHOUdHURY department of Electrical Engineering Indian Institute of Technology (IIT) department of Instrumentation and Control Engineering delhi University department of Information Technology (I.T.) M.A.I.T.

In this paper, a technique is presented to determine the stability margin of the discrete systems using recursive algorithm for power of companion matrix and Gerschgorin Theorem and hence sufficient condition of stability is obtained. The method is illustrated with an example and it is compared with other methods proposed in the literature. The results have applications in the filter design.

关键词： Gerschgorin theorem power of companion matrix discrete systems Stability margin

A robust test of uncertain linear systems

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控制理论与应用（英文版） 2009年第3期7卷 277-280页

作者： Yogesh V. HOTE d. roy CHOUdHURY J. R. p. GUpTA department of Instrumentation and Control Engineering Delhi University department of Computer Engineering I. P. University

In this paper, it is shown that for low-order uncertain systems, there is no need to calculate all the minimum and maximum values of the coefficients for a perturbed system which is expressed in terms of polynomials and hence no need to formulate and test all the four Kharitonov＇s polynomials. Furthermore, for higher-order systems such as n ≥ 5, the usual four Kharitonov＇s polynomials need not be tested initially for sufficient condition of perturbed systems; rather, the necessary condition can be checked before going for sufficient condition. In order to show the effectiveness of the proposed method, numerical examples are shown and computational efficiency is highlighted.

关键词： Kharitonov's theorem Robust stability Routh criterion

Characterizing Shorea robusta communities in the part of Indian Terai landscape

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Journal of Forestry Research 2014年第1期25卷 121-128页

作者： V.S.Chitale M.d.Behera S.Matin p.S.roy V.K.Sinha Spatial Analysis and Modeling Laboratory Centre for Oceans RiversAtmosphere and Land Sciences (CORAL)Indian Institute of Technology (IIT) Kharagpur Center for Earth and Space Sciences University of Hyderabad Uttar pradesh State Forest dept.

Shorea robusta Gaertn. f.（Sal）is one of the important tim-ber-yielding plants in India, which dominates the vegetation of Terai landscape of Uttar pradesh state in India forming various communities based on its associations. The present study deals with delineation, map-ping and characterization of various communities of Sal （Shorea robusta） forests in Terai landscape of Uttar pradesh, India ranging across over 16 districts. Field survey and visual interpretation based forest vegetation type classification and mapping was carried out as part of the project entitled ‘Biodiversity characterization at landscape level using remote sensing and GIS’. Indian Remote Sensing-p6 （Resourcesat-1） Linear Imaging Self Scanner-III satellite data was used during the study. The total area covered by different Sal forests was found to be approximately 2256.77 km2. Sal communities were identified and characterized based on their spectral properties, physiognomy and phytosociological charac-teristics. Following nine Sal communities were identified, delineated and mapped with reasonable accuracyviz.,Chandar,damar, dry plains, moist plains, western alluvium, western alluvium plains, mixed moist deciduous, mixed dry deciduous andSiwalik. It is evident from the area estimates that mixed moist deciduous Sal is the most dominant commu-nity in the region covering around （1613.90 km2）, other major communi-ties were found as western alluvium plains Sal （362.44 km2）, mixed dry deciduous Sal （362.44 km2） and dry plains Sal （107.71 km2）. The Terai landscape of Uttar pradesh faces tremendous anthropogenic pressure leading to deterioration of the forests. Community level information could be used monitoring the status as well as for micro level conserva-tion and planning of the Sal forests in Terai Landscape of Uttar pradesh.

关键词： Vegetation mapping LISS III Forest management Microlevel Conservation

putting meaning into NETMAR-the open service network for marine environmental data

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International Journal of digital Earth 2014年第10期7卷 811-828页

作者： Adam M.Leadbetter roy K.Lowry d.Oliver Clements British Oceanographic data Centre LiverpoolUK plymouth Marine Laboratory PlymouthUK

The open service network for marine environmental data(NETMAR)project uses semantic web technologies in its pilot system which aims to allow users to search,download and integrate satellite,in situ and model data from open ocean and coastal *** semantic web is an extension of the fundamental ideas of the World Wide Web,building aweb of datathrough annotation of metadata and data with hyperlinked *** the framework of the NETMAR project,an interconnected semantic web resourcewasdeveloped to aid in dataandweb service discovery and to validate Open Geospatial Consortium Web processing Service orchestration.A second semantic resource was developed to support interoper-ability of coastal web atlases across jurisdictional *** paper outlines the approach taken to producing the resource registry used within the NETMAR project and demonstrates the use of these semantic resources to support user interactions with *** interconnected semantic resources allow the increased ability to share and disseminate data through the facilitation of interoperability between data *** formal representation of geospatial knowledge to advance geospatial interoperability is a growing research *** and methods such as those outlined in this paper have the potential to support these efforts.

关键词： geoinformatics oceanography geospatial data integration