2,098 research outputs found
Detection and Recognition of Traffic Sign using FCM with SVM
This paper mainly focuses on Traffic Sign and board Detection systems that have been placed on roads and highway. This system aims to deal with real-time traffic sign and traffic board recognition, i.e. localizing what type of traffic sign and traffic board are appears in which area of an input image at a fast processing time. Our detection module is based on proposed extraction and classification of traffic signs built upon a color probability model using HAAR feature Extraction and color Histogram of Orientated Gradients (HOG).HOG technique is used to convert original image into gray color then applies RGB for foreground. Then the Support Vector Machine (SVM) fetches the object from the above result and compares with database. At the same time Fuzzy Cmeans cluster (FCM) technique get the same output from above result and then to compare with the database images. By using this method, accuracy of identifying the signs could be improved. Also the dynamic updating of new signals can be done. The goal of this work is to provide optimized prediction on the given sign
Investigation on the source location of flares associated with type II radio bursts using multi-wavelength observations
In this paper, a set of 145 type II bursts-associated solar flares observed during the period November1997 to December 2006 has been investigated. The radio bursts have been observed by Culgoora radio spectrograph and X-ray flares have been observed by GOES spacecraft. The main objectives are to study the distribution of locations of flares associated with type II bursts on the Sun and association of type II radio bursts with major solar flares and halo CMEs. Among the different latitudinal bins considered, more number of events occurred in the active latitude range 11-20° in both hemispheres. Shifting of dominance of type II-associated flare events from higher latitudes to equator has been seen from the butterfly diagram. Among the different longitudinal bins, more number of type IIs are found in the solar active longitudes around 50 degrees on both the eastern and western regions and in the range 10-20° west. That might be due to the favorable ambient/source conditions in the solar corona. In addition, the DH type II association with metric type IIs has been found to be nearly absent beyond the east longitude 50°. This east-west asymmetry in the low frequency type II bursts (DH type IIs) may be due to emission directivity of the low frequency radiations produced by CME-driven shocks
Lesions mimicking lacrimal gland pleomorphic adenoma
Aim: To report a series of patients with lacrimal gland lesions simulating the clinicoradiological features of lacrimal gland pleomorphic adenoma (LGPA). Methods: Multicentre retrospective, interventional case series. Clinical records of all patients with lesions mimicking LGPA seen in five orbital units were reviewed. Results: The study included 14 patients (seven men and seven women) with a mean age of 50.9 years. The diagnosis of LGPA was made in all cases by experienced orbital surgeons, based on clinicoradiological features, and lacrimal gland excision was performed. Postoperative histology revealed lymphoma (four patients), chronic dacryoadenitis (three patients), adenoid cystic carcinoma (two patients), Sjogren's syndrome (two patients), cavernous haemangioma (one patient), benign lymphoid hyperplasia (one patient) and granulomatous dacryoadenitis (one patient). Comparison with the total number of histologically confirmed LGPA cases seen during the study period revealed that 22.6% of cases of suspected LGPA were misdiagnosed based on clinicoradiological criteria. Conclusions: Many different lesions may mimic the clinicoradiological features of LGPA. The accepted clinicoradiological criteria used for the diagnosis of LGPA have a high false-positive rate, even in experienced hands. Based on this study, the authors believe that fine-needle aspiration biopsy or intraoperative biopsy and frozen section diagnosis may help reduce unnecessary lacrimal gland excision.Venkatesh C Prabhakaran, Paul S Cannon, Alan McNab, Garry Davis, Brett O’Donnell, Peter J Dolman, Raf Ghabrial, Dinesh Selv
Integration of stochastic models for long-term eruption forecasting into a Bayesian event tree scheme: a basis method to estimate the probability of volcanic unrest
Eruption forecasting refers, in general, to the
assessment of the occurrence probability of a given erup-
tive event, whereas volcanic hazards are normally associated
with the analysis of superficial and evident phenomena
that usually accompany eruptions (e.g., lava, pyroclastic
flows, tephra fall, lahars, etc.). Nevertheless, several hazards
of volcanic origin may occur in noneruptive phases dur-
ing unrest episodes. Among others, remarkable examples
are gas emissions, phreatic explosions, ground deforma-
tion, and seismic swarms. Many of such events may lead to
significant damages, and for this reason, the “risk” associ-
ated to unrest episodes could not be negligible with respect
to eruption-related phenomena. Our main objective in this
paper is to provide a quantitative framework to calculate
probabilities of volcanic unrest. The mathematical frame-
work proposed is based on the integration of stochastic mod-
els based on the analysis of eruption occurrence catalogs
into a Bayesian event tree scheme for eruption forecast-
ing and volcanic hazard assessment. Indeed, such models
are based on long-term eruption catalogs and in many
cases allow a more consistent analysis of long-term tem-
poral modulations of volcanic activity. The main result of
this approach is twofold: first, it allows to make inferences
about the probability of volcanic unrest; second, it allows
to project the results of stochastic modeling of the eruptive
history of a volcano toward the probabilistic assessment of
volcanic hazards. To illustrate the performance of the pro-
posed approach, we apply it to determine probabilities of
unrest at Miyakejima volcano, Japan
Experimental investigation on flow induced vibration excitation in the elastically mounted square cylinders
In this paper an experimental investigation is performed on a range of transverse gap ratios (0.5≤T/D≤4.5) between the cylinders arranged in side by side configuration. The pattern of the test cylinder motion, spectral diagram and amplitude are used to analyze the vibration excitation at different conditions such as free stream velocity, natural frequency of the test cylinder. From the results, for the spacing ratio of T/D= 0.5 it is observed that the cylinders gets excited beyond the critical velocity and vibrates in a spiral pattern with the line dominated spectrum, which implies that by having a similar frequency along with a phase shift, the characteristics behavior of the cylinder is observed to be like an oscillator with the cross wise and stream wise response. Besides that, it is also observed that the cylinders at higher spacing ratios (T/D= 4.5) producing minimum oscillation when compared to the smaller spacing ratios
Persistent currents in two dimensions: New regimes induced by the interplay between electronic correlations and disorder
Using the persistent current I induced by an Aharonov-Bohm flux in square
lattices with random potentials, we study the interplay between electronic
correlations and disorder upon the ground state (GS) of a few polarized
electrons (spinless fermions) with Coulomb repulsion. K being the total
momentum, we show that I is proportional to K in the continuum limit. We use
this relation to distinguish between the continuum regimes, where the lattice
GS behaves as in the continuum limit and I is independent of the interaction
strength U when K is conserved, and the lattice regimes where I decays as U
increases. Changing the disorder strength W and U, we obtain many regimes which
we study using the map of local currents carried by three spinless fermions
Densities and phase equilibria of hydrogen, propane and vegetable oil mixtures. Experimental data and thermodynamic modeling
Heterogeneous catalytic gas-liquid reactions are intensified when carried out in the homogenous fluid phase by means of a supercritical co-solvent. For instance, supercritical propane is used to enhance yield in the hydrogenation of vegetable oils. Besides phase equilibrium knowledge, volumetric information is also needed to elucidate kinetic mechanisms and design continuous supercritical reactors. In this work, we report new experimental PvT data of the reactive mixture H2+sunflower oil+propane using the isochoric method. In addition, the phase equilibria and PvT data are modeled with the GCA and RK-PR equations of state, respectively. The isochoric method not only provides PvT information under the reaction conditions, but also the reactive system compressibility, key variable to attain enhanced transport properties in the supercritical reactors.Fil: Hegel, Pablo Ezequiel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Planta Piloto de IngenierĂa QuĂmica. Universidad Nacional del Sur. Planta Piloto de IngenierĂa QuĂmica; ArgentinaFil: Cotabarren, Natalia Soledad. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Planta Piloto de IngenierĂa QuĂmica. Universidad Nacional del Sur. Planta Piloto de IngenierĂa QuĂmica; ArgentinaFil: Brignole, Esteban Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Planta Piloto de IngenierĂa QuĂmica. Universidad Nacional del Sur. Planta Piloto de IngenierĂa QuĂmica; ArgentinaFil: Pereda, Selva. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Planta Piloto de IngenierĂa QuĂmica. Universidad Nacional del Sur. Planta Piloto de IngenierĂa QuĂmica; Argentina. University of KwaZulu-Natal; Sudáfric
Recent Progress in Semiconductor Photocatalysis for Organic Fine Chemical Synthesis
Photocatalytic process is a well-known reaction in photosynthesis by plants and algae. Artificial photosynthesis is a chemical process that mimics the natural plant photosynthesis to make important chemicals by using man-made materials. One of the most promising methods of artificial photosynthesis is synthesis of organic chemicals, including biodegradable plastics, pharmaceutical drugs, liquid fuels and intermediates for valuable chemicals, etc. In 1972, Fujishima and Honda discovered photocatalytic process using TiO2 semiconductor oxide electrodes to generate hydrogen from water. Researchers have achieved a single-step system that uses semiconductor particles for organic fine chemical synthesis under UV or visible radiation. This chapter summarizes the recent research trends on artificial photosynthesis by photocatalytic process for organic fine chemical synthesis on selected photocatalytic organic transformations, especially photocatalytic transformations by oxidation, carbon-carbon and carbon-heteroatom coupling, cyclization, etc
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