Search results for "Filter"
showing 10 items of 1019 documents
Diffusion equations with negentropy applied to denoise mammographic images.
2006
Mammography is a radiographic technique used for the detection of breast lesions. The analysis of the digital image normally requires a previous application of filters as a preprocessing step to reduce the noise level of the image, while preserving important details to carry out a suitable diagnostic. In the literature, there are a large amount of denoising techniques applied to different medical images. In this work we have studied the performance of a diffusive filter with a stopping condition based on the statistical concept of negentropy, applied to denoise mammographic images. The negentropy has been succesfully prove with other denoising methods as independent component analysis by th…
<title>Achieving high performances at lower cost for real-time image rotation by using dynamic reconfiguration</title>
2001
FPGA components are widely used today to perform various algorithms (digital filtering) in real time. The emergence of Dynamically Reconfigurable (DR) FPGAs made it possible to reduce the number of necessary resources to carry out an image processing application (tasks chain). We present in this article an image processing application (image rotation) that exploits the FPGA's dynamic reconfiguration feature. A comparison is undertaken between the dynamic and static reconfiguration by using two criteria, cost and performance criteria. For the sake of testing the validity of our approach in terms of Algorithm and Architecture Adequacy , we realized an AT40K40 based board ARDOISE.
Challenges and Opportunities using MultiChain for Real Estate
2019
The real estate market involves multiple untrusted actors with contrasting objectives. We propose REchain, a blockchain-based platform for real estate, which provides benefits to all actors in terms of transparency, trust, immutability, and traceability. REchain architecture handles real estate data through well-defined workflows that leverage the MultiChain platform. REchain changes the real estate market enabling direct transactions without intermediaries, and providing new mechanisms for negotiating the purchase conditions. This paper refutes the misleading idea of using blockchains for solving generic problems as blockchain platforms have peculiar features that make them suitable for sp…
Extended complex Kalman filter for sensorless control of an induction motor
2014
Abstract This paper deals with the design of an extended complex Kalman filter (ECKF) for estimating the state of an induction motor (IM) model, and for sensorless control of systems employing this type of motor as an actuator. A complex-valued model is adopted that simultaneously allows a simpler observability analysis of the system and a more effective state estimation. The observability analysis of this model is first performed by assuming that a third order ECKF has to be designed, by neglecting the mechanical equation of the IM model, which is a valid hypothesis when the motor is operated at constant rotor speed. It is shown that this analysis is more effective and easier than the one …
Sub-critical long-term operation of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system
2012
The aim of this study was to evaluate the long-term performance of hollow-fibre (HF) membranes used to treat urban wastewater in a submerged anaerobic MBR when operating sub-critically. To this end, a demonstration plant with two industrial scale HF ultrafiltration membrane modules was operated under different conditions. The main factor affecting membrane performance was the concentration of mixed liquor total solids (MLTS). The reversible fouling rate remained low even when MLTS levels (about 25 g L−1) in the membrane tank were high. No chemical cleaning was conducted whilst operating the plant for more than one year because no irreversible fouling problems were detected. The almost compl…
On an Inequality for Legendre Polynomials
2020
This paper is concerned with the orthogonal polynomials. Upper and lower bounds of Legendre polynomials are obtained. Furthermore, entropies associated with discrete probability distributions is a topic considered in this paper. Bounds of the entropies which improve some previously known results are obtained in terms of inequalities. In order to illustrate the results obtained in this paper and to compare them with other results from the literature some graphs are provided.
Biofiltration System for Purification of Composting Waste Gases
2006
The biofiltration technique for the purification of polluted air from composting facility volatile compounds was studied. Two different biowaste composting techniques were compared with regard to emission of NH3 and H2S. The ammonia removal was observed in aerobic phase of active composting period, respectively H2S in anaerobic phase. Biofiltration process was realized in modified solid- state fermentation system (SSF). The biodegradation of volatile compounds was investigated in one and two stage systems with inert packing material and hemoautotrofic microorganisms designed DN-1 (Pseudomonas sp.), DN-2 (Nitrisomonas sp.), DN-3 (Nitrobacter sp.) and DN-13 (Sarcina sp.) and Thiopharus-3. The…
Separating compound figures in journal articles to allow for subfigure classification
2013
Journal images represent an important part of the knowledge stored in the medical literature. Figure classification has received much attention as the information of the image types can be used in a variety of contexts to focus image search and filter out unwanted information or ”noise”, for example non–clinical images. A major problem in figure classification is the fact that many figures in the biomedical literature are compound figures and do often contain more than a single figure type. Some journals do separate compound figures into several parts but many do not, thus requiring currently manual separation. In this work, a technique of compound figure separation is proposed and implemen…
An approach based on the Adaptive Resonance Theory for analysing the viability of recommender systems in a citizen Web portal
2007
This paper proposes a methodology to optimise the future accuracy of a collaborative recommender application in a citizen Web portal. There are four stages namely, user modelling, benchmarking of clustering algorithms, prediction analysis and recommendation. The first stage is to develop analytical models of common characteristics of Web-user data. These artificial data sets are then used to evaluate the performance of clustering algorithms, in particular benchmarking the ART2 neural network with K-means clustering. Afterwards, it is evaluated the predictive accuracy of the clusters applied to a real-world data set derived from access logs to the citizen Web portal Infoville XXI (http://www…
Digital slicing of 3D scenes by Fourier filtering of integral images
2008
We present a novel technique to extract depth information from 3D scenes recorded using an Integral Imaging system. The technique exploits the periodic structure of the recorded integral image to implement a Fourier-domain filtering algorithm. A proper projection of the filtered integral image permits reconstruction of different planes that constitute the 3D scene. The main feature of our method is that the Fourier-domain filtering allows the reduction of out-of-focus information, providing the InI system with real optical sectioning capacity.