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Calicut, India

The National Institute of Technology Calicut ,, , formerly the Calicut Regional Engineering College , is a federally funded technical university and an institute of national importance governed by an act passed by the Parliament of India. The campus is situated at Chathamangalam, 22 kilometres north east of Kozhikode, formerly known as Calicut, on the Kozhikode–Mukkam Road. It was established in 1961 and was known as Calicut Regional Engineering College until 2002. It is one of the National Institutes of Technology established by the Government of India for imparting high standard technical education to students from all over the country. The college is among the very few institutions in the country to host a Supercomputer of its own. Wikipedia.

Nanthagopalan P.,National Institute of Technology Calicut | Santhanam M.,Indian Institute of Technology Madras
Cement and Concrete Composites

Self-compacting concrete (SCC) is extensively applied in many construction projects due to its excellent fresh and hardened concrete properties. In recent years, manufactured sand (Msand) produced by crushing rock deposits is being identified as a suitable alternative source for river sand in concrete. The main objective of this study is to explore the possibility of using Msand in SCC. In this process, an attempt was made to understand the influence of paste volume and w/p ratio (water to powder ratio) on the properties of self-compacting concrete (SCC) using Msand. The powder and aggregate combinations were optimised by using the particle packing approach, which involves the selection of combinations having maximum packing density. The chemical admixtures (superplasticisers, viscosity modifying agent) were optimised based on simple empirical tests. Fresh concrete tests such as slump flow, T500 and J-ring were performed on SCC; hardened concrete tests were limited to compressive strength. From the results, it was observed that relatively higher paste volume is essential to achieve the required flow for SCC using Msand, as compared to river sand. Low and medium strength (25-60 MPa) SCCs were achieved by using Msand based on the approach adopted in the study. Results showed that it is possible to successfully utilise manufactured sand in producing SCC. © 2011 Published by Elsevier Ltd. Source

Subha D.P.,National Institute of Technology Calicut
Journal of medical systems

The EEG (Electroencephalogram) signal indicates the electrical activity of the brain. They are highly random in nature and may contain useful information about the brain state. However, it is very difficult to get useful information from these signals directly in the time domain just by observing them. They are basically non-linear and nonstationary in nature. Hence, important features can be extracted for the diagnosis of different diseases using advanced signal processing techniques. In this paper the effect of different events on the EEG signal, and different signal processing methods used to extract the hidden information from the signal are discussed in detail. Linear, Frequency domain, time - frequency and non-linear techniques like correlation dimension (CD), largest Lyapunov exponent (LLE), Hurst exponent (H), different entropies, fractal dimension(FD), Higher Order Spectra (HOS), phase space plots and recurrence plots are discussed in detail using a typical normal EEG signal. Source

Camilus K.S.,National Institute of Technology Calicut
Journal of applied clinical medical physics / American College of Medical Physics

In most of the approaches of computer-aided detection of breast cancer, one of the preprocessing steps applied to the mammogram is the removal/suppression of pectoral muscle, as its presence within the mammogram may adversely affect the outcome of cancer detection processes. Through this study, we propose an efficient automatic method using the watershed transformation for identifying the pectoral muscle in mediolateral oblique view mammograms. The watershed transformation of the mammogram shows interesting properties that include the appearance of a unique watershed line corresponding to the pectoral muscle edge. In addition to this, it is observed that the pectoral muscle region is oversegmented due to the existence of several catchment basins within the pectoral muscle. Hence, a suitable merging algorithm is proposed to combine the appropriate catchment basins to obtain the correct pectoral muscle region. A total of 84 mammograms from the mammographic image analysis database were used to validate this approach. The mean false positive and mean false negative rates, obtained by comparing the results of the proposed approach with manually-identified (ground truth) pectoral muscle boundaries, respectively, were 0.85% and 4.88%. A comparison of the results of the proposed method with related state-of-the-art methods shows that the performance of the proposed approach is better than the existing methods in terms of the mean false negative rate. Using Hausdorff distance metric, the comparison of the results of the proposed method with ground truth shows low Hausdorff distances, the mean and standard deviation being 3.85 ± 1.07 mm. Source

Nidheesh P.V.,National Institute of Technology Calicut
RSC Advances

Fenton processes have gained much attention in the field of wastewater treatment during recent years. In order to overcome the disadvantages of Fenton processes, research has focused more on the heterogeneous Fenton process, with highly active and stable solid catalysts. This review reports on advances in the field of heterogeneous Fenton processes in recent years, especially focusing on the various heterogeneous catalysts used. After a general introduction to the various Fenton processes, their advantages and the importance of heterogeneous Fenton processes, various catalysts used in heterogeneous Fenton processes are described in detail. These catalysts are divided into iron minerals, zero-valent iron, waste materials, iron- and iron oxide-loaded materials, and clay. The properties, stability, activity and pollutant degradation mechanism of various catalysts are also discussed in detail. © The Royal Society of Chemistry 2015. Source

Manoj V.J.,Kerala University | Elias E.,National Institute of Technology Calicut
Information Sciences

Nonuniform filter bank transmultiplexer (NUFB TMUX) can be used to implement multicarrier communication system where applications with different data rates are to be multiplexed. It is possible to reduce the hardware complexity of the NUFB TMUX by representing the filter coefficients in canonic signed digit (CSD) format. In this paper the design of a multiplier-less NUFB TMUX is presented. NUFB TMUX with continuous filter coefficients is designed and the filter coefficients are synthesized in CSD format. Filter coefficient synthesis in CSD format is formulated as an optimization problem and an artificial bee colony (ABC) algorithm is used for the optimization. To preserve the canonic nature of filter coefficients in the ABC algorithm the filter coefficients are encoded using a look-up table. The look-up table also provides the number of signed power-of-two (SPT) terms in the CSD numbers. Simulation results show that the performance of the multiplier-less NUFB TMUX designed using the proposed ABC algorithm is much better than that of the multiplier-less NUFB TMUX obtained by rounding the continuous coefficients of filters to the nearest CSD number. Multiplier-less NUFB TMUX designed by the proposed ABC algorithm also outperforms that designed using genetic algorithm (GA) and particle swarm optimization (PSO). © 2010 Elsevier Inc. All rights reserved. Source

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