What About Spectrum Opportunities in ‘Angle’ Dimension for Dynamic Spectrum Access in Cognitive Radio Network context? A new Paradigm in Spectrum Sensing

The cognitive radio technology is the new paradigm to fulfill ever increasing need of bandwidth ultimately the radio spectrum by accommodating the radio spectrum dynamically to secondary users/unlicensed users without causing the interference. In cognitive radio, the spectrum opportunities have been checked for Space, Time and frequency dimensions but ‘Angle’ dimension has not been explored till now. In this paper we have investigated accuracy of various ‘Angle-of-Arrival (AoA)’ estimation algorithms: ESPRIT, MUSIC, Bartlett, and Capon for opportunistic secondary users’ network under AWGN and time varying fading channels. The improvement in performance of these algorithms has been observed as array elements, signal-to-noise ratio and samples increases. An ‘adaptive thresholding’ technique has been proposed to improve the performance of AoA algorithms. Thus by estimating an ‘Angle-of- Arrival’ of licensed users, the unlicensed users can be accommodated in the same geographical area into the same channel in the same frequency band at the same time by directing unlicensed users’ beam in different direction than the direction of licensed users. Thereby improving spectrum utilization.     

An integrated ISM fuzzy MICMAC approach for modelling the supply chain knowledge flow enablers

The aim of this study is to identify supply chain knowledge flow enablers (SCKFEs) to inspect interrelationships among these enablers and classify these enablers into driving power and dependence power using an integrated interpretive structural modelling (ISM) and fuzzy Matriced Impacts Croisés Multiplication Appliquée á un Classement (MICMAC) methodology. While the ISM methodology analyses the interactions among the SCKFEs, fuzzy MICMAC analysis is employed to obtain insights into the dependencies among the SCKFEs. A total of 34 SCKFEs were identified through the literature review and expert opinion. As an example, an Indian manufacturing organisation is selected that is willing to adopt the successful knowledge flow for improving supply chain (SC) performance to overcome the intense competition among the SC versus SC. The research shows SCKFEs having high driving power and low dependence have strategic importance because of their driving nature, while the SCKFEs having high dependence and low driving power are more performance orientated. Therefore, it is the responsibility of SC executives to address the high driving power SCKFEs for the enhancement of SC performance. This categorisation provides a useful tool to top management to differentiate between independent and dependent SCKFEs and their mutual relationships, helping them focus on those key SCKFEs that are most significant. This gives a clear picture to SC practitioners and decision-makers about number of SCKFEs, interrelationship and dependencies existing among them.     

A contact‐point based approach for the analysis of reactions among solid particles

The contact‐point framework, 1 which replaces the picture of continuous contact between the reactants by contact at a finite number of points, has been proposed as a rational one for treating reactions among particulate solids. However, available models suffer from various drawbacks, the main one being that they do not show the right asymptotic behavior for large number of contact points. A model is presented here, that corrects these deficiencies. The results show that the contact‐point model approaches particle‐continuum behavior whenever the number of contact points exceeds 500. The model predictions have been compared with some data from our previous work on calcia‐alumina system in the temperature range 1,150–1,300°C. The model fits the data well, with the fitted values of diffusivity (of calcia through alumina) being of the order of 10^?16 m²/s. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

Manifold Preserving CNN for Pixel-Based Object Labelling in Images for High Dimensional Feature spaces

Neural Processing Letters - Deep CNN’s have achieved an excellent performance in computer vision and image processing methods, designating them as a state-of-art in this domain. CNN based...     

Process optimization and kinetic modeling for esterification of propionic acid with benzyl alcohol on ion-exchange resin catalyst

Benzyl propionate, an ester with floral and fruity odor, has significant applications in perfumery and flavor industries. This paper describes the optimization of the synthesis of benzyl propionate catalyzed by Amberlyst-15. The effects of various process parameters such as catalyst loading, alcohol-to-acid molar ratio and reaction temperature on propionic acid conversion and yield of ester were assessed by response surface methodology (RSM). The external and internal mass transfer limitations were found to be absent. Analysis of variance (ANOVA) showed that the acquired quadratic model successfully interpreted the experimental data with the coefficient of determination values, (R²>0.98) and adjusted R² values, (>0.97). The RSM model was validated by good agreement between the model predicted and experimental values for responses. Pseudohomogeneous (PH) kinetic model was used and validated (R²>0.95) with the experimental data. The activation energy and frequency factor were evaluated as 42.07 kJ mol^?1 and 19,874.64 L mol^?1 min^?1, respectively.     

A Review on Minimum Quantity Lubrication for Machining Processes

In the pursuit toward achieving dry cutting, air machining, minimum quantity lubrication (MQL), and cryogenically cooled machining are the stepping stones. Nevertheless, machining is always accompanied by certain difficulties, and hence none of these methods has provided a complete solution. Hence, this article reviews various MQL methods used by various machining processes for different materials. It also highlights the future work directions for research in this area.     

Effect of Thermal Treatment on Chemical Interaction Between Yttrium Borosilicate Glass Sealants and YSZ for Planar Solid Oxide Fuel Cells

This article is to address the bonding and sealing capability of two yttrium borosilicate glasses. These glass seals have been tested with AISI 441 steel and high-temperature solid electrolyte that is yttria-stabilized zirconia (YSZ), as a function of different heating durations for planar solid oxide fuel cell applications in air atmosphere. The diffusion couples were prepared by slurry coating and then subjected to heat-treatment for different time durations of 1, 100, and 500 h at 850°C. In addition to this, the diffusion couples with YSZ were also thermally cycled between room temperature and 850°C. These prepared diffusion couples have been characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS). XRD indicated surface crystallization of the coating glass/YSZ diffusion couple. MgY glass sample shows less devitrification than the CaY glass. The overall analysis of the resulting microstructure by SEM/EDS revealed improvement in adhesion with increase in time duration of heat treatment as well as thermally cycled sample without any detrimental phase formation. The diffusion couples with AISI 441 steel have shown good adhesion with crack-free interface.     

A 1 GS/s, 31 MHz BW, 76.3 dB dynamic range, 34 mW CT-\Updelta\Upsigma ADC with 1.5 cycle quantizer delay and improved STF

A 1 GS/s continuous-time delta-sigma modulator (CT- $\Updelta\Upsigma$ M) with 31 MHz bandwidth, 76.3 dB dynamic range and 72.5 dB peak-SNDR is reported in a 0.13 μm CMOS technology. The design employs an excess loop delay (ELD) of more than one clock cycle for achieving higher sampling rate. The ELD is compensated using a fast-loop formed around the last integrator by using a sample-and-hold. Further, the effect of this ELD compensation scheme on the signal transfer function (STF) of a feedforward CT- $\Updelta\Upsigma$ architecture has been analyzed and reported. In this work, an improved STF is achieved by using a combination of feed-forward, feed-back and feed-in paths and power consumption is reduced by eliminating the adder opamp. This CT- $\Updelta\Upsigma$ M has a conversion bandwidth of 31 MHz and consumes 34 mW from the 1.2 V power supply. The relevant design trade-offs have been investigated and presented along with simulation results.