Search results for "difference"

showing 10 items of 1534 documents

How Universal Is the Relationship between Remotely Sensed Vegetation Indices and Crop Leaf Area Index? A Global Assessment

2016

This study aims to assess the relationship between Leaf Area Index (LAI) and remotely sensed Vegetation Indices (VIs) for major crops, based on a globally explicit dataset of in situ LAI measurements over a significant set of locations. We used a total of 1394 LAI measurements from 29 sites spanning 4 continents and covering 15 crop types with corresponding Landsat satellite images. Best-fit functions for the LAI-VI relationships were generated and assessed in terms of crop type, vegetation index, level of radiometric/atmospheric processing, method of LAI measurement, as well as the time difference between LAI measurements and satellite overpass. These global LAI-VI relationships were evalu…

Agroecosystemagroecosystem modeling010504 meteorology & atmospheric sciencesMean squared error0211 other engineering and technologiesRobust statisticsLAI; Vegetation Index; agriculture; Landsat; agroecosystem modeling02 engineering and technologyCrop01 natural sciencesUniversalityNormalized Difference Vegetation IndexArticleLAI-VI relationshipLeaf area indexlcsh:Science021101 geological & geomatics engineering0105 earth and related environmental sciencesMathematicsRemote sensingagriculture2. Zero hungerGlobalEnhanced vegetation index15. Life on landLAIGeneral Earth and Planetary Scienceslcsh:QSymbolic regressionLandsatAgricultural landscapesVegetation Index
researchProduct

The Relationships between Early Trauma, Dissociation, and Alexithymia in Alcohol Addiction

2014

Objective Addiction is often considered a dissociative behavior that is related to alexithymia and developmental trauma. The study aims were to explore the relationships between early trauma, alexithymia, and dissociation. Methods A total of 117 (males=60; females=57) alcohol-addicted individuals and 117 healthy individuals (males=60; females=57) were administered a series of self-report questionnaires that assess traumatic experiences, alexithymia, and pathological dissociation. Results Correlation analyses indicated significant correlations between alexithymia, dissociation, and trauma and a significant difference between the target and control groups, with higher alexithymia and dissocia…

Alexithymiamedicine.medical_specialtyDissociation (neuropsychology)medicine.drug_classmedia_common.quotation_subjectAlcohol addictionEarly traumaDissociativeHV Social pathology. Social and public welfare. CriminologyAlexithymiamedicinePsychiatryPathologicalBiological Psychiatrymedia_commonAlcohol addictionbusiness.industryAddictionBrief ReportSignificant differencemedicine.diseasePsychiatry and Mental healthHealthy individualsRA Public aspects of medicinebusinessDissociationClinical psychologyPsychiatry Investigation
researchProduct

Absolute and monotonic norms

1961

AlgebraComputational MathematicsAbsolute (philosophy)Difference polynomialsApplied MathematicsNumerical analysisLinear algebraMonotonic functionMathematicsNumerische Mathematik
researchProduct

All-Optical frequency Shifter in a Periodically Poled Lithium Tantalate Waveguide

2011

A frequency shifting device is fabricated and tested in a congruent Lithium Tantalate waveguide. Periodic poling for quasi-phase-matching and channels for operation in the near-infrared C-band were obtained, demonstrating a two-stage parametric conversion.

All-optical wavelength conversion second-harmonic generation difference-frequency generation ferroelectric crystals periodic poling Lithium Tantalate Lithium Niobate.Settore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - Elettronica
researchProduct

A marching-on in time meshless kernel based solver for full-wave electromagnetic simulation

2012

A meshless particle method based on an unconditionally stable time domain numerical scheme, oriented to electromagnetic transient simulations, is presented. The proposed scheme improves the smoothed particle electromagnetics method, already developed by the authors. The time stepping is approached by using the alternating directions implicit finite difference scheme, in a leapfrog way. The proposed formulation is used in order to efficiently overcome the stability relation constraint of explicit schemes. In fact, due to this constraint, large time steps cannot be used with small space steps and vice-versa. The same stability relation holds when the meshless formulation is applied together w…

Alternating directions implicit scheme · Finite difference time domain · Meshless methods · Electromagnetic transient analysisRegularized meshless methodElectromagneticsApplied MathematicsNumerical analysisMathematical analysisFinite-difference time-domain methodSolverSettore ING-IND/31 - ElettrotecnicaSettore MAT/08 - Analisi NumericaKernel (image processing)Meshfree methodsApplied mathematicsTime domainMathematicsNumerical Algorithms
researchProduct

Application of analogy in the teaching of french in China

2014

The analogy refers to a non-coincidental similarity between two things or two ideas of different nature. It is a cognitive process whereby information attached to a specific element is transferred to another specific element, and plays an important role in the process of memorization, communication and problem solving. It is used as a method in many disciplines, it also has its own definition in different areas. In linguistic research, the analogy is also a very interesting topic. According to our research, we find that the analogy has an important influence on the creation and the evolution of a language, when we learn a language, the correct analogy also plays a positive role, it is possi…

AnalogieAnalogyEnseignement du françaisDifférencesSimilaritiesFrench teachingDifferences[SHS.LANGUE] Humanities and Social Sciences/LinguisticsSimilarités
researchProduct

Exploring the validity of the long term data record V4 database for land surface monitoring

2015

The last (and final) version of the Long Term Data Record (LTDR) — Version 4 — has been released recently by NASA. This database includes daily information for all AVHRR (Advanced Very High Resolution Radiometer) channels, as well as ancillary data, since July 1981 up to present. This database is the longest available record of remotely sensed data useful for land surface monitoring, since it allows the estimation of vegetation indices at daily resolution, as well as the daily estimation of land surface temperature (LST). Here, we analyze the fitness of this database for land surface monitoring. To that end, we first estimated NDVI (Normalized Difference Vegetation Index), LST, as well as e…

Ancillary dataSeries (stratigraphy)GeographyDatabaseAdvanced very-high-resolution radiometerLong term dataSolar zenith angleVegetationTime seriescomputer.software_genrecomputerNormalized Difference Vegetation IndexRemote sensing2015 8th International Workshop on the Analysis of Multitemporal Remote Sensing Images (Multi-Temp)
researchProduct

Base Excess and Strong Ion Difference: Clinical Limitations Related to Inaccuracy

2004

Anesthesiology and Pain MedicineBiochemistrybusiness.industryReference valuesStatisticsMEDLINEMedicineBase excessbusinessStrong ion differenceAnesthesiology
researchProduct

A circular mesh scheme for the non-orthogonal finite difference time domain method

2002

Beam forming networks (BFN) are an important component of a complex satellite antenna system because they are used to provide accurate amplitude and phase excitation to the elements of the feed network. The need for handling high power and the need for a high degree of integrability, often leads one to choose square coaxial metal lines for constructing BFNs. BFNs usually require variable power dividers such as the rat-race (or ring) couplers with constant or variable divider ratios in order to deliver a prescribed amount of power to a certain element of an antenna array to steer the beam in a desired direction. However, modeling of such circular structures in square coaxial form is not an e…

Antenna arrayEngineeringbusiness.industryMesh generationNumerical analysisFinite difference methodFinite-difference time-domain methodElectronic engineeringCoaxialbusinessTopologySquare (algebra)Power (physics)IEEE Antennas and Propagation Society International Symposium. 1995 Digest
researchProduct

Electromagnetic Sensitivity Analysis and Shape Optimization Using Method of Moments and Automatic Differentiation

2009

Sensitivity analysis is an important part of gradient-based optimization of electromagnetic devices. We demonstrate how sensitivity analysis can be incorporated into an existing in-house method of moments solver with a relatively small amount of labor by using a technique called automatic differentiation (AD). This approach enables us to obtain (geometrical) sensitivities of the discrete solution with accuracy up to numerical precision. We compare the assembly time and memory usage of the modified and original solvers. Moreover, we optimize the shape of a dipole antenna and the dimensions of a Yagi-Uda array using the presented AD technique, traditional response level finite difference sens…

Antenna arrayMathematical optimizationAutomatic differentiationFinite difference methodShape optimizationSensitivity (control systems)Electrical and Electronic EngineeringMethod of moments (statistics)SolverAlgorithmGradient methodMathematicsIEEE Transactions on Antennas and Propagation
researchProduct