Detecting and Mitigating Selfish Primary Users in Cognitive Radio

Wireless Personal Communications - In today’s world, Cloud computing based health cloud is an effective platform for enhancing e-health productivity, i.e., healthcare professionals can...     

Con(dif)fused voice to convey secret: a dual-domain approach

Owing to the rapid development and advancements in the field of networks and communication, sharing of multimedia contents over insecure networks has becom     

Performance Evaluation of Compressed Air Energy Storage Using TRNSYS

The appreciable economic growth in some of the developing countries like India in the recent years, towards providing energy security causes large environmental impact. Renewable Energy (RE) is being seen as one of the important means to meet the growing power needs of the economy while enhancing energy security and providing opportunities for mitigating greenhouse gas emissions. However, RE sources are highly intermittent in nature. The variability of these sources has led to concerns regarding the reliability of an electric grid that derives a large fraction of its energy from these sources as well as the cost of reliably integrating large amounts of variable generation into the electric grid. Hence at this juncture, it is necessary to explore the benefits of suitable Energy storage technologies. Compressed air energy storage (CAES) is a commercial, utility-scale technology that provides long-duration energy storage with fast ramp rates and good part-load operation. It is a promising storage technology for balancing the large-scale penetration of renewable energies, such as wind and solar power, into electric grids. Considering the potential of CAES storage, the present work, a thermodynamic model is developed with suitable assumptions and the simulation analysis is performed using transient system simulation (TRNSYS) v17 software. The system performance is compared by considering the recovery during the heat of compression using a thermal storage system and without considering the heat recovery. The overall turnaround efficiency of the system without considering the thermal energy storage (TES) system is 57% and with TES system the efficiency is increased to 70%.     

Synthesis,characterization and properties of photoresponsive polymers comprising photocrosslinkable pendant chalcone moieties

New methacrylate monomers, namely 4‐methacryloyloxyphenyl‐4′‐fluorostyryl ketone and 4‐methacryloyloxyphenyl‐4′‐ethylstyryl ketone comprising a free radical polymerizable group and a photocrosslinkable group, were synthesized by reacting the respective hydroxychalcones with methacryloyl chloride in the presence of triethylamine. The monomers were polymerized in the presence of ethyl methyl ketone (EMK) at 70 °C using benzoyl peroxide as the initiator. The chemical structures were characterized using various spectroscopic techniques: ultraviolet, Fourier transform infrared, ¹H NMR and ¹³C NMR. The thermal stability of the polymers was studied using thermogravimetric analysis in nitrogen atmosphere. Differential scanning calorimetry was used to determine the glass transition temperature of the homopolymers. Photocrosslinking of the synthesized homopolymers was investigated in solution. The two homopolymers were crosslinked within 10–15 min. After crosslinking, the homopolymers were insoluble in the same solvent. Copyright © 2006 Society of Chemical Industry     

ECC joins first time with SC-FDMA for Mission “security”

The recent advancements in the internet technology have created the urgency in developing critical data security framework around the globe. One of the most shared multimedia objects is the image which is safeguarded through a task called image encryption. An integrated approach to image encryption is the need of the hour which can combine algorithm and communication model. In this context, this work presents the first- of- its- kind approach addressing Elliptic Curve Cryptography (ECC) to encrypt and decrypt the images to enhance their security during transmission via Single Carrier Frequency Division Multiple Access (SC-FDMA) communication systems. The uniqueness of this work is to combine the encryption scheme and subsequent wireless transmission. Modified Huffman coding has been employed to achieve compression. The viability of the proposed approach was tested and the performance metrics namely Entropy, PSNR, Histogram, correlation coefficient, differential attack, NIST test, and occulation attack analyses were evaluated. The simulation results prove the efficiency of the proposed integrated encryption – compression – communication schema.

     

Contamination assessment of heavy metals in the soils of an abandoned copper mine in Lasail,Northern Oman

ABSTRACT

Abandoned mine areas exhibit heavy metal contamination. This severely reduces the soil quality. This paper concerns the assessment of soils near an abandoned copper mine in Lasail, northern Oman. Seventy-two soil samples were collected and analysed for heavy metals using inductively coupled plasma optical emission spectrometry (ICP-OES). The extent of heavy metal pollution was evaluated based on the geo-accumulation index (Igeo), enrichment factor (EF), and pollution index (PI). According to these indices, Copper (Cu), Mercury (Hg), Zinc (Zn), Arsenic (As) and Iron (Fe) are impacting the soils. Of these, Cu and Hg concentrations are 50 and 300 times more than the permissible limits set by the World Health Organization (WHO). There is an urgent need for the remediation and restoration of the soils in this area and a proposal is presented here.     

Transient thermal management comparison of a microprocessor using PCMs in various configurations

There has been a strong interest in the use of Phase Change Materials (PCMs) for the transient thermal abatement of high powered microprocessor. This paper presents a set of transient computational analysis for selected IC packages with the purpose of calibrating the merits of PCM in different configurations. The transient analysis of high powered microprocessors with heat sinks was performed as a benchmark for comparison with the same microprocessors fitted with PCM in the following configurations: a) PCM imbedded into the finned region of the heat sink, b) PCM mounted between the microprocessor and heat sink, c) sealed PCM underfill to the microprocessor and d) PCM fitted to the underside of the printed circuit board directly beneath the microprocessor. The analysis was performed using a commercial CFD tool together with an approximation to the phase change mechanism using the slope method. Results indicate the merit of each configuration.     

Segmentation of hepatocellular carcinoma and dysplastic liver tumors in histopathology images using area based adaptive expectation maximization

The differentiation of a cluster of nuclei and multi-nucleation is a critical issue in automated diagnosis systems. Due to the similarities between said clusters and malignant nuclei, misclassification of these regions can affect the automated systems’ final decision. In this paper, a method for differentiating clusters from multi nucleated cells in histopathological images is proposed. Hepatocellular Carcinoma(HCC) and Dysplasia are characterized by cellular and nuclear enlargement, nuclear pleomorphism and multinucleation, which possess prominent threat Data was obtained from Global Hospital and Research Center from patients diagnosed with Hepatocellular Carcinoma and Dysplasia. This paper introduces a hybrid diagnosis method that uses texture, layout and context features of nuclei and cytoplastic cells in order to enhance the poor diagnosis of liver tumors in Infra Red (IR) images. We propose a Area based Adaptive Expectation Maximization(EM) that grows the clusters, which avoids the need for initial cluster selection in order to obtain texton maps of nuclei and cytoplasm. A linear regression model of nuclei and cytoplastic changes were built by incorporating the aforementioned features efficiently. The proposed method provides better classification and segmentation accuracy of nuclei and extra nuclear content in HCC and dysplasia, compared to the state-of-the-art methods like convolutional networks and classical methods like Adaptive K means and EM method in constant time. In conclusion, this system detects the malignant cells and the highly eligible precancerous cells which is cost effective and reproducible.     

A Review on Efficient Routing Mechanisms in Urban Scenario of Vehicular Ad-Hoc Networks

Efficient routing protocols are crucial for enabling secure communication among the highly mobile and self-configurable nodes in Vehicular Ad-Hoc Networks(VANETs). In this work, we present a performance evaluation of different routing protocols in VANETs based on the currently available research. Our study focuses on analyzing the strength and weaknesses of the routing protocols, namely, Ad-Hoc On-demand Distance Vector(AODV), Dynamic Source Routing(DSR), and Destination-Sequenced Distance-Vecto...