33,047 research outputs found

    Image segmentation and feature extraction for recognizing strokes in tennis game videos

    Get PDF
    This paper addresses the problem of recognizing human actions from video. Particularly, the case of recognizing events in tennis game videos is analyzed. Driven by our domain knowledge, a robust player segmentation algorithm is developed real video data. Further, we introduce a number of novel features to be extracted for our particular application. Different feature combinations are investigated in order to find the optimal one. Finally, recognition results for different classes of tennis strokes using automatic learning capability of Hidden Markov Models (HMMs) are presented. The experimental results demonstrate that our method is close to realizing statistics of tennis games automatically using ordinary TV broadcast videos

    Synthetic heparinoids labelled with 125I and 35S

    Get PDF
    The labelling of a water-soluble synthetic polyelectrolyte, having anticoagulant activity, has been studied. The polyelectrolyte is derived from cis-1,4-polyisoprene and contains N-sulfate and carboxylate groups. [125I]-Iodination of the polyelectrolyte, using the Chloramine-T method and an electrolytic method, resulted in a [125I]-labelled polyelectrolyte from which release of the label occurred. Resulfation of a partially desulfated polyelectrolyte with a [35S]-sulfur trioxide trimethylamine complex resulted in a [35S]-labelled polyelectrolyte which showed no release of the label

    C2_2H observations toward the Orion Bar

    Get PDF
    C2_2H is one of the first radicals to be detected in the interstellar medium. Its higher rotational transitions have recently become available with the Herschel Space Observatory. We aim to constrain the physical parameters of the C2_2H emitting gas toward the Orion Bar. We analyse the C2_2H line intensities measured toward the Orion Bar CO+^+ Peak and Herschel/HIFI maps of C2_2H, CH, and HCO+^+, and a NANTEN map of [CI]. We interpret the observed C2_2H emission using radiative transfer and PDR models. Five rotational transitions of C2_2H have been detected in the HIFI frequency range toward the CO+^+ peak. A single component rotational diagram gives a rotation temperature of ~64 K and a beam-averaged C2_2H column density of 4×\times1013^{13} cm2^{-2}. The measured transitions cannot be explained by any single parameter model. According to a non-LTE model, most of the C2_2H column density produces the lower-NN C2_2H transitions and traces a warm (TkinT_{\rm{kin}} ~ 100-150 K) and dense (nn(H2_2)~105^5-106^6 cm3^{-3}) gas. A small fraction of the C2_2H column density is required to reproduce the intensity of the highest-NN transitions (NN=9-8 and N=10-9) originating from a high density (nn(H2_2)~5×\times106^6 cm3^{-3}) hot (TkinT_{\rm{kin}} ~ 400 K) gas. The total beam-averaged C2_2H column density in the model is 1014^{14} cm2^{-2}. Both the non-LTE radiative transfer model and a simple PDR model representing the Orion Bar with a plane-parallel slab of gas and dust suggest, that C2_2H cannot be described by a single pressure component, unlike the reactive ion CH+^+, which was previously analysed toward the Orion Bar CO+^+ peak. The physical parameters traced by the higher rotational transitions (NN=6-5,...,10-9) of C2_2H may be consistent with the edges of dense clumps exposed to UV radiation near the ionization front of the Orion Bar.Comment: Proposed for acceptance in A&A, abstract abridge

    Pairing in cuprates from high energy electronic states

    Full text link
    The in-plane optical conductivity of Bi2Sr2CaCu2O8+d thin films with small carrier density (underdoped) up to large carrier density (overdoped) is analyzed with unprecedented accuracy. Integrating the conductivity up to increasingly higher energies points to the energy scale involved when the superfluid condensate builds up. In the underdoped sample, states extending up to 2 eV contribute to the superfluid. This anomalously large energy scale may be assigned to a change of in-plane kinetic energy at the superconducting transition, and is compatible with an electronic pairing mechanism.Comment: 11 pages, 3 figure

    Retrieval of canopy component temperatures through Bayesian inversion of directional thermal measurements

    Get PDF
    Evapotranspiration is usually estimated in remote sensing from single temperature value representing both soil and vegetation. This surface temperature is an aggregate over multiple canopy components. The temperature of the individual components can differ significantly, introducing errors in the evapotranspiration estimations. The temperature aggregate has a high level of directionality. An inversion method is presented in this paper to retrieve four canopy component temperatures from directional brightness temperatures. The Bayesian method uses both a priori information and sensor characteristics to solve the ill-posed inversion problem. The method is tested using two case studies: 1) a sensitivity analysis, using a large forward simulated dataset, and 2) in a reality study, using two datasets of two field campaigns. The results of the sensitivity analysis show that the Bayesian approach is able to retrieve the four component temperatures from directional brightness temperatures with good success rates using multi-directional sensors (Srspectra˜0.3, Srgonio˜0.3, and SrAATSR˜0.5), and no improvement using mono-angular sensors (Sr˜1). The results of the experimental study show that the approach gives good results for high LAI values (RMSEgrass=0.50 K, RMSEwheat=0.29 K, RMSEsugar beet=0.75 K, RMSEbarley=0.67 K); but for low LAI values the results were unsatisfactory (RMSEyoung maize=2.85 K). This discrepancy was found to originate from the presence of the metallic construction of the setup. As these disturbances, were only present for two crops and were not present in the sensitivity analysis, which had a low LAI, it is concluded that using masked thermal images will eliminate this discrepanc

    Comment on "Systematics of the Induced Magnetic Moments in 5d Layers and the Violation of the Third Hund's Rule"

    Full text link
    Comment on F. Wilhelm et al., Phys. Rev. Lett. 87, 207202 (2001)Comment: 1 pag

    The content and context of organizational ethics

    Get PDF
    The aim of this paper is to provide an empirical contextual picture of what is truly valued most in different public and private sector organizations. Through a series of qualitative in-depth interviews (n = 38), that were a follow-up to an earlier survey study among public and private sector managers (n = 382), a number of crucial organizational values were presented to and discussed with a selection of top managers from a variety of Dutch public and private sector organizations. The decision-making context from the interviews provides insight into why, when, how and to what extent specific values are important. A number of unexpected differences and similarities between organizations with a different sectoral status emerge from the data, which shed new light on existing predispositions on value preferences in government and business conduct. © 2010 The Author. Public Administration © 2010 Blackwell Publishing Ltd

    BRDFs acquired by directional radiative measurements during EAGLE and AGRISAR

    Get PDF
    Radiation is the driving force for all processes and interactions between earth surface and atmosphere. The amount of measured radiation reflected by vegetation depends on its structure, the viewing angle and the solar angle. This angular dependence is usually expressed in the Bi-directional Reflectance Distribution Function (BRDF). This BRDF is not only different for different types of vegetation, but also different for different stages of the growth. The BRDF therefore has to be measured at ground level before any satellite imagery can be used the calculate surface-atmosphere interaction. The objective of this research is to acquire the BRDFs for agricultural crop types. A goniometric system is used to acquire the BRDFs. This is a mechanical device capable of a complete hemispherical rotation. The radiative directional measurements are performed with different sensors that can be attached to this system. The BRDFs are calculated from the measured radiation. In the periods 10 June - 18 June 2006 and 2 July - 10 July 2006 directional radiative measurements were performed at three sites: Speulderbos site, in the Netherlands, the Cabauw site, in the Netherlands, and an agricultural test site in Goermin, Germany. The measurements were performed over eight different crops: forest, grass, pine tree, corn, wheat, sugar beat and barley. The sensors covered the spectrum from the optical to the thermal domain. The measured radiance is used to calculate the BRDFs or directional thermal signature. This contribution describes the measurements and calculation of the BRDFs of forest, grassland, young corn, mature corn, wheat, sugar beat and barley during the EAGLE2006 and AGRISAR 2006 fieldcampaigns. Optical BRDF have been acquired for all crops except barley. Thermal angular signatures are acquired for all the crop
    corecore