Relevant and significant supervised gene clusters for microarray cancer classification

An important application of microarray data in functional genomics is to classify samples according to their gene expression profiles such as to classify cancer versus normal samples or to classify different types or subtypes of cancer. One of the major tasks with gene expression data is to find co-regulated gene groups whose collective expression is strongly associated with sample categories. In this regard, a gene clustering algorithm is proposed to group genes from microarray data. It directly incorporates the information of sample categories in the grouping process for finding groups of co-regulated genes with strong association to the sample categories, yielding a supervised gene clustering algorithm. The average expression of the genes from each cluster acts as its representative. Some significant representatives are taken to form the reduced feature set to build the classifiers for cancer classification. The mutual information is used to compute both gene-gene redundancy and gene-class relevance. The performance of the proposed method, along with a comparison with existing methods, is studied on six cancer microarray data sets using the predictive accuracy of naive Bayes classifier, K-nearest neighbor rule, and support vector machine. An important finding is that the proposed algorithm is shown to be effective for identifying biologically significant gene clusters with excellent predictive capability.     

Efficient design of bio-basis function to predict protein functional sites using kernel-based classifiers

In order to apply the powerful kernel-based pattern recognition algorithms such as support vector machines to predict functional sites in proteins, amino acids need encoding prior to input. In this regard, a new string kernel function, termed as the modified bio-basis function, is proposed that maps a nonnumerical sequence space to a numerical feature space. The proposed string kernel function is developed based on the conventional bio-basis function and needs a bio-basis string as a support like conventional kernel function. The concept of zone of influence of a bio-basis string is introduced in the proposed kernel function to take into account the influence of each bio-basis string in nonnumerical sequence space. An efficient method is described to select a set of bio-basis strings for the proposed kernel function, integrating the Fisher ratio and a novel concept of degree of resemblance. The integration enables the method to select a reduced set of relevant and nonredundant bio-basis strings.     

Young citizens’ knowledge and perceptions of bioenergy and future policy implications

In the past few years extensive discussions on bioenergy has been both positive and negative. In Europe, the image of bioenergy appears to be low with lack of broad public support. Previous studies show that younger people are unsure about many issues surrounding renewable energy. The aim of this study was to investigate the knowledge and perceptions of bioenergy among pupils in North Karelia, Finland. Data drawn from 495 ninth grade students indicate that the majority of them lack in-depth knowledge about different renewable energy sources, including bioenergy. Only a small percentage has a ‘high’ level of knowledge about bioenergy and the majority indicates critical perceptions of it. Statistically significant gender differences are not apparent. Girls appear to be more knowledgeable than boys. Results also show a clear ‘urban’ and ‘rural’ difference in perceptions of bioenergy. Perceptions of urban respondents being more positive than that of their rural counterparts. Developing collaboration between future bioenergy policies and bioenergy education for younger citizens is necessary for their engagement in critical debates on bioenergy.     

A surface potential based drain current model for asymmetric double gate MOSFETs

In this paper, we present a generic surface potential based current voltage (I-V) model for doped or undoped asymmetric double gate (DG) MOSFET. The model is derived from the 1-D Poisson’s equation with all the charge terms included and the channel potential is solved for the asymmetric operation of DG MOSFET based on the Newton-Raphson iterative method. A noncharge sheet based drain current model based on the Pao-Sah’s double integral method is formulated in terms of front and back gate surface potentials at the source and drain end. The model is able to clearly show the dependence of the front and back surface potential and the drain current on the terminal voltages, gate oxide thicknesses, channel doping concentrations and the Silicon body thickness and a good agreement is observed with the 2-D numerical simulation results.     

A 2‐D surface‐potential‐based threshold voltage model for short channel asymmetric heavily doped DG MOSFETs

In recent times, transistors with heavily doped body have generated much interest because of junctionless channel. In addition, proper threshold voltage regulation requires adjustment of the channel doping, as a result of which most of the compact models become invalid as they consider an intrinsic body. In this paper, a compact surface‐potential‐based threshold voltage model is developed for short channel asymmetric double‐gate metal–oxide–semiconductor field‐effect transistors with heavily/lightly doped channel. The 2‐D surface potential is computed and compared with Technology Computer Aided Design, and a relative error of 2–4 % was obtained. The threshold voltage is solved from 2‐D Poisson's equation using ‘virtual cathode’ method, and a good agreement is observed with the numerical simulations. Also, the model is compared with a reference model and a better result is obtained for heavily doped channel. Copyright © 2014 John Wiley & Sons, Ltd.     

An experimental study on the shattering behavior of a high strength armour steel under blast and long rod penetrator impact

Armour steel plates with drilled holes are filled with explosive and subjected to single or multiple blasts to induce shattering. The critical diameter for shattering under explosive detonation, found from the experiments matches closely with that of the long rod penetrator impacted plates. The damage pattern and fracture surface of the tested samples under blast effect have been compared with plates impacted with long rod penetrators for matching the observed shattering behavior. Difference in the shattering behavior of the armour steel subjected to single and multiple blasts has also been presented.     

Moving object detection using spatio-temporal multilayer compound Markov Random Field and histogram thresholding based change detection

Multimedia Tools and Applications - In this article, we propose a Multi Layer Compound Markov Random Field (MLCMRF) Model to spatially segment different image frames of a given video sequence. The...     

Electronic transport properties of electrically doped cytosine‐based optical molecular switch with single‐wall carbon nanotube electrodes

This study represents an empirical model of cytosine‐based optical molecular switch. This possible biomolecular switch has been designed using the first principle approach which is based on density functional theory and non‐equilibrium Green''s function. The quantum‐ballistic transport property and current–voltage (I–V) characteristics of cytosine‐based optomolecular switch have been investigated at 25 THz operating frequency. The influence of highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) gaps on the electronic transmission and I–V characteristics has been discussed in detail. The aim of this study is to highlight the minimum conformational change during a single ON–OFF switching cycle. The biomolecule comprises switching behaviour when converts from straightened to twisted form during photo‐excitement. The straightened and twisted forms of the molecule are represented as logic ‘0’ and logic ‘1’, respectively. This p and n regions of this switch has been made using electrical doping process. The current through the twisted form of the cytosine biomolecule is ∼1000 times higher than the straightened form. The maximum switching ratio 62.1 is obtained at 1 V bias. The origin of the switching behaviour of the biomolecule can be interpreted by quantum–ballistic transport model along with HOMO–LUMO gaps.Inspec keywords: ballistic transport, organic compounds, Green''s function methods, ab initio calculations, density functional theory, molecular biophysics, optical switches, single‐wall carbon nanotubes, electrochemical electrodesOther keywords: electrical doping process, cytosine biomolecule, electronic transport properties, single‐wall carbon nanotube electrodes, cytosine‐based optical molecular switch, density functional theory, electronic transmission, HOMO‐LUMO gaps, current–voltage characteristics, biomolecular switching behaviour, quantum–ballistic transport property model, electrically doped cytosine‐based optical molecular switch, first principle approach, nonequilibrium Green''s function, I‐V characteristics, highest occupied molecular orbital–lowest unoccupied molecular orbital gaps, single ON–OFF switching cycle, photoexcitement, frequency 25.0 THz, voltage 1.0 V, C     

First principle study of the self‐switching characteristics of the guanine based single optical molecular switch using carbon nanotube electrodes

The switching property of an optical single molecular switch based on a single DNA molecule guanine with a single walled carbon nanotube electrode has been investigated using density functional theory along with non‐equilibrium Green''s function based first principle approach. The semi‐empirical model of this single bio‐molecular switch has been operated at an ultra‐high 25 THz frequency in mid‐UV range. This single bio‐molecule comprises switching activity upon UV photo‐excitation. The influence of the highest occupied molecular orbital and lowest unoccupied molecular orbital gap and the quantum ballistic transmission into the switching activity are discussed in detail in this study. It has been observed that the maximum ON–OFF ratio, i.e. 327 is obtained at +0.8 V bias voltage. Theoretical results show that current through the twisted form is sufficiently larger than the straightened form, which recommends that this structure has smart prospective application in the future generation switching nanotechnology.Inspec keywords: molecular electronic states, density functional theory, ab initio calculations, DNA, organic compounds, molecular electronics, Green''s function methods, molecular biophysics, single‐wall carbon nanotubes, optical switches, orbital calculationsOther keywords: nonequilibrium Green''s function, semiempirical model, single bio‐molecular switch, UV photo‐excitation, lowest unoccupied molecular orbital gap, first principle study, single optical molecular switch, switching property, optical single molecular switch, single DNA molecule guanine, single walled carbon nanotube electrode, density functional theory, highest occupied molecular orbital gap, switching nanotechnology