27,280 research outputs found
Composition, distribution and supposed origin of mineral inclusions in sessile oak wood - consequences for microdensitometrical analysis
SEM and light-microscopical observations, supported by chemical microanalysis with an EDXA system, revealed that light-saturated pixels observed in X-ray negatives of sessile oak (Quercus petraea Liebl.) wood were caused by inorganic deposits present inside multiseriate ray and axial parenchyma cells. Calcium oxalate crystals, silica grains and amorphous granules with varied mineral compositions have been identified. The wood strips of three out of six sampled trees contained measurable amounts of mineral inclusions which were quantified using image analysis. Based on the variations of mineral content observed between trees and within and between annual rings of the same tree, some hypotheses were formulated concerning the factors involved in the formation of inorganic deposits in oak wood. Their occurrence varies depending on the mineral concerned and seems to be controlled largely by a tree eïŹect. The time of formation appears to coincide with a shifting of the oak woodâs functions as a result of heartwood formation processes (inter-annual scale) or changes in leaf phenology and climate (intra-annual scale). In addition, the technical consequences of their presence as well as their eïŹects on wood density measurements through microdensitometry are discussedComposition, distribution et origine supposĂ©e dâinclusions minĂ©rales dans le bois de chĂȘne sessile â consĂ©quences pour lâanalyse microdensitomĂ©trique. Des observations Ă lâaide de microscopes Ă©lectronique Ă balayage et optique, appuyĂ©es par des analyses Ă©lĂ©mentaires au moyen dâun systĂšme EDXA, ont rĂ©vĂ©lĂ© que les points-images saturĂ©s en niveau de gris, constatĂ©s dans les nĂ©gatifs de radiographies de bois de chĂȘne sessile (Quercus petraea Liebl.), Ă©taient dus Ă des dĂ©pĂŽts inorganiques prĂ©sents Ă lâintĂ©rieur des cellules parenchymateuses des rayons ligneux multisĂ©riĂ©s et du parenchyme axial. Des cristaux dâoxalate de calcium, des grains de silice et des granules amorphes ayant des compositions minĂ©rales variĂ©es ont Ă©tĂ© identifiĂ©s. Des barrettes de trois sur six arbres Ă©chantillonnĂ©s contenaient des quantitĂ©s mesurables dâinclusions minĂ©rales qui ont Ă©tĂ© quantifiĂ©es par analyse dâimages. En se basant sur les variations du contenu en dĂ©pĂŽts minĂ©raux observĂ©es entre arbres ainsi quâĂ lâintĂ©rieur dâun arbre, aux niveaux intra- et intercerne, quelques hypothĂšses ont Ă©tĂ© avancĂ©es concernant les facteurs potentiellement responsables de la formation de dĂ©pĂŽts minĂ©raux chez le chĂȘne. Leur prĂ©sence dĂ©pend du minĂ©ral concernĂ© et semble ĂȘtre contrĂŽlĂ©e par un fort eïŹet arbre. Lâapparition des minĂ©raux coĂŻncide apparemment avec des changements de fonctions du bois relatifs aux processus de duraminisation (Ă©chelle interannuelle) ou correspondant Ă des Ă©volutions phĂ©nologiques ou climatiques (Ă©chelle intra-annuelle). Enfin, les consĂ©quences techniques ainsi que les eïŹets de leur prĂ©sence sur des mesures de la densitĂ© du bois par analyse microdensitomĂ©trique sont discutĂ©
Curved Gabor Filters for Fingerprint Image Enhancement
Gabor filters play an important role in many application areas for the
enhancement of various types of images and the extraction of Gabor features.
For the purpose of enhancing curved structures in noisy images, we introduce
curved Gabor filters which locally adapt their shape to the direction of flow.
These curved Gabor filters enable the choice of filter parameters which
increase the smoothing power without creating artifacts in the enhanced image.
In this paper, curved Gabor filters are applied to the curved ridge and valley
structure of low-quality fingerprint images. First, we combine two orientation
field estimation methods in order to obtain a more robust estimation for very
noisy images. Next, curved regions are constructed by following the respective
local orientation and they are used for estimating the local ridge frequency.
Lastly, curved Gabor filters are defined based on curved regions and they are
applied for the enhancement of low-quality fingerprint images. Experimental
results on the FVC2004 databases show improvements of this approach in
comparison to state-of-the-art enhancement methods
Recommended from our members
ToScA North America (6 â 8 June 2017, The University of Texas, Austin, TX) Program
ToScA North America will address key areas of science,
including Multi-modal Imaging, Geosciences, Forensics, Increasing Contrast,
Educational Outreach, Data, Materials Science and Medical and Biological
Science.University of Texas High-Resolution X-ray CT Facility (UTCT);
Jackson School of Geosciences, The University of Texas at Austin;
Natural History Museum (London);
Royal Microscopical Society (Oxford, UK)Geological Science
Modeling nature-based and cultural recreation preferences in mediterranean regions as opportunities for smart tourism and diversification
The tourism and recreational o er of Mediterranean destinations involves, essentially,
the promotion of mass tourism, based on the appeal of the sun and beach, and the quality of its
coastal assets. Alongside the impacts of climate change, poor tourism diversification represents
a threat to the resilience of the territory. Thus, heterogenization of noncoastal tourism products
presents an opportunity to strengthen regional resilience to present and future challenges, hence
the need to study, comparatively, the complementary preferences of tourists and residents of these
regions in order to unveil their willingness to diversify their recreational experience, not only in
coastal spaces, but alsoâand especiallyâin interior territories with low urban density. Consequently,
this strategic option may represent a way of strengthening resilience and sustainability through
diversification. In this context, a survey was conducted among 400 beach tourists and 400 residents
of a case studyânamely, three municipalities of the Algarve region in southern Portugalâin order to
analyze their degree of preference for activities besides the sun and beach, such as nature-based and
cultural tourism activities, and to probe the enhancement potential of each tourism and recreational
activity through the various landscape units considered by experts, stakeholders, and tour operators.
The respective degree of preference and enhancement potential were indexed to the area of each
landscape unit. Subsequently, respecting the existing recreational structure and constraints, a
suitability map for territory enhancement and the implementation of smart tourism practices for each
tourism activity and landscape unit is presented. Results show a significant preference for noncoastal
outdoor recreational activities.FCT- Fundação para a CiĂȘncia e Tecnologia: SFRH/BD/102328/2014; PTDC/GES-URB/31928/2017info:eu-repo/semantics/publishedVersio
Remote sensing applications to forest vegetation classification and conifer vigor loss due to dwarf mistletoe
Criteria was established for practical remote sensing of vegetation stress and mortality caused by dwarf mistletoe infections in black spruce subboreal forest stands. The project was accomplished in two stages: (1) A fixed tower-tramway site in an infected black spruce stand was used for periodic multispectral photo coverage to establish basic film/filter/scale/season/weather parameters; (2) The photographic combinations suggested by the tower-tramway tests were used in low, medium, and high altitude aerial photography
Recent trends, technical concepts and components of computer-assisted orthopedic surgery systems: A comprehensive review
Computer-assisted orthopedic surgery (CAOS) systems have become one of the most important and challenging types of system in clinical orthopedics, as they enable precise treatment of musculoskeletal diseases, employing modern clinical navigation systems and surgical tools. This paper brings a comprehensive review of recent trends and possibilities of CAOS systems. There are three types of the surgical planning systems, including: systems based on the volumetric images (computer tomography (CT), magnetic resonance imaging (MRI) or ultrasound images), further systems utilize either 2D or 3D fluoroscopic images, and the last one utilizes the kinetic information about the joints and morphological information about the target bones. This complex review is focused on three fundamental aspects of CAOS systems: their essential components, types of CAOS systems, and mechanical tools used in CAOS systems. In this review, we also outline the possibilities for using ultrasound computer-assisted orthopedic surgery (UCAOS) systems as an alternative to conventionally used CAOS systems.Web of Science1923art. no. 519
Neural Network for Papaya Leaf Disease Detection
The scientific name of papaya is Carica papaya which is an herbaceous perennial in the family Caricaceae grown for its edible fruit. The papaya plant is tree-like,usually unbranched and has hollow stems and petioles. Its origin is Costa Rica, Mexico and USA. The common names of papaya is pawpaw and tree melon. In East Indies and Southern Asia, it is known as tapaya, kepaya, lapaya and kapaya. In Brazil,it is known as Mamao. Papayas are a soft, fleshy fruit that can be used in a wide variety of culinary ways. The possible health benefits of consuming papaya include a reduced risk of heart disease, diabetes, cancer, aiding in digestion, improving blood glucose control in people with diabetes, lowering blood pressure, and improving wound healing.
Disease identification in early stage can increase crop productivity and hence lead to economical growth. This work deals with leaf rather than fruit. Images of papaya leaf samples, image compression and image filtering and several image generation techniques are used to obtain several trained data image sets and then hence providing a better product. This paper focus on the power of neural network for detecting diseases in the papaya. Image segmentation is done with the help of k-medoid clustering algorithm which is a partitioning based clustering method
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