1,721,044 research outputs found
Optimized cloud-based scheduling for protein secondary structure analysis
No full textIn the domain of proteomics, an in-depth analysis of the 3D struc- ture of a protein is of paramount importance for many biological studies and applications. At the secondary level, protein structure can be described in terms of motifs, recurrent patterns of smaller biological structures called Sec- ondary Structure Elements. In this paper, the focus is on the identi cation of geometrical motifs in dif- ferent proteins using the Cross Motif Search Algorithm (CMS). Such task, due to the high computational cost of CMS with respect to traditional alignment algorithms, is very demanding, and thus parallel processing is mandatory. In previous papers, CMS parallelization has been already studied from the HPC standpoint. Since cloud computing is emerging as an alternative to on- premise HPC systems, it is worthwhile examining the feasibility and possible advantages in terms of both performance and costs, of migrating to a cloud implementation. This paper is an extension of a preliminary work [1] carried out on the cloud parallelization of CMS. The paper has two main contributions. First of all, an analytic model of the communication pattern of CMS is described, in order to get insights on the performance of the application when executed on a cloud infrastructure. Secondly, an optimized location-aware" scheduling policy to assign workload to the application workers is introduced, in order to minimize internode communication in a cloud setting
Understanding effects of atmospheric variables on spectral vegetation indices derived from satellite based time series of multispectral images
No full textIn agricultural practices, it is very essential to monitor crops phenological pattern over the time to manage agronomic activities such as irrigation, weed control, pest control, fertilization, drainage system etc. From the past decade, due to free availability of data and large coverage area, satellite based remote sensing has been most popular and widely used among other techniques such as physical ground surveys, ground based sensors and aerial based remote sensing. Sentinel-2 is European based satellite equipped with the state of the art multispectral imager which offers high spectral resolution (13- spectral bands), high spatial resolution (up to 10m pixel -1 ) and good temporal resolution (6 to 10days). Considering these features, time series of multispectral images of sentinel-2 has been used to establish temporal pattern of spectral vegetation indices (i.e. NDVI, SAVI, EVI, RVI) of crops to monitor the phenological behavior over time. In addition, the influence of various atmospheric variables (such as temperature in the air and precipitation ) on the derived spectral vegetation indices has also been investigated in this work. Land use and coverage area frame survey (LUCAS-2015) has been used as ground reference data for this study. This study shows that by using sentinel-2, understanding relation between atmospheric conditions and crops phenological behavior can be useful to manage agricultural activities
Analyzing relationship between maize height and spectral indices derived from remotely sensed multispectral imagery
No full textFor maize crop, biophysical parameters such as canopy height and above ground biomass are the crucial agro-ecological indicator that can be used to describe the crop growth, photosynthetic efficiency and carbon stock. Remote sensing is widely used approach and most appropriate source in terms of area coverage that can be used to monitor vegetative conditions over the large area. In this study, sentinel-2 multispectral imagery is used to calculate spectral vegetation indices over the different maize growth period using some visible bands including near infrared spectrum. The relationship has been established and analyzed between maize biophysical variables (height of the canopy and above ground biomass) collected during the field measurements and derived spectral vegetation indices using simple linear regression and pearson correlation to exploit the possibility of using satellite imagery for estimation of crop biophysical parameters
Reliability of the geometric calibration of an hyperspectral frame camera
Full text linkOne of the main tools for high resolution remote sensing and photogrammetry is the lightweight hyperspectral frame camera, that is used in several application areas such as precision agriculture, forestry, and environmental monitoring. Among these types of sensors, the Rikola (which is based on a Fabry–Perot interferometer (FPI) and produced by Senop) is one of the latest innovations. Due to its internal geometry, there are several issues to be addressed for the appropriate definition and estimation of the inner orientation parameters (IOPs). The main problems concern the possibility to change every time the sequence of the bands and to assess the reliability of the IOPs. This work focuses the attention on the assessment of the IOPs definition for each sensor, considering the impact of environmental conditions (e.g., different time, exposure, brightness) and different configurations of the FPI camera, in order to rebuild an undistorted hypercube for image processing and object estimation. The aim of this work is to understand if the IOPs are stable over the time and if and which bands can be used as reference for the calculation of the inner parameters for each sensor, considering different environmental configurations and surveys, from terrestrial to aerial applications. Preliminary performed tests showed that the focal length percentage variation among the bands of different experiments is around 1%
Microstructural Study of Vanadium-Titanium Oxide Powders Obtained by Laser-Induced Synthesis
No full textUsing laser-induced pyrolysis, powder samples of pure TiO2 and mixed oxides with different vanadium content were prepared and analyzed by XRD. The diffraction patterns were interpreted in microstructural terms by Fourier analysis of their peak profiles. The influence of vanadium on the phase transition was studied and the changes in the particle and microstrain distributions obtained at different temperatures were analyzed. There is an evident correlation between the initial microstrain distribution in the Ti1-xVxO2 powder and the vanadium content. The segregation of the V2O5 phase causes a strain reduction into the anatase structure. We suggest that the previously observed lowering of the transition temperature for the anatase-to-rutile transformation in the presence of vanadium is due to distortions induced by this ion in the anatase structure
Gas chromatographic–mass spectrometric characterisation of the Italian Protected Designation of Origin “Altamura” bread volatile profile
No full textDynamic headspace extraction technique coupled to the gas chromatography–mass spectrometry analysis was applied to characterize volatile compounds of both crust and crumb of the Protected Designation of Origin Italian durum wheat sourdough “Altamura” bread. Volatile compounds of crust and crumb were characterized and statistically compared and their relative abundance was also calculated. A total of 89 compounds belonging to different chemical classes were identified in the crust. More abundant compounds detected in the crust were ethanol (20 ± 6%), 2-furfural (14 ± 7%) and 3-methyl-1-butanol (9 ± 5%). A lower number of volatile compounds (74) was identified in crumb, among which ethanol (32 ± 7%), 3-methyl-1-butanol (23 ± 6%) and 3-pentanol (7 ± 3) were the most abundant. The influence of different baking modes (wood- or gas-fired) on volatile compounds, macroscopic appearance and selected physico-chemical parameters (colour and texture) of bread samples were also evaluated.
Samples baked in wood-fired oven showed larger amount of volatile compounds such as furans and aldehydes that could positively influence the flavour of the product.
Crust of wood-fired breads showed higher amounts of compounds from Maillard reaction, resulting in harder and browner breads than gas-fired samples. Macroscopic appearance of crumb of wood-fired breads showed higher percentages of larger pores, being also less hard and cohesive than gas-fired samples
Geometrical 3D model generation of rock blocks using low-cost photogrammetry [Article@Ricostruzione geometrica 3D di blocchi di roccia mediante fotogrammetria low cost]
No full textSpatial distribution and movements of wildebeest and zebra in Tarangire National Park, northern Tanzania
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