A novel seed based random interleaving for OFDM system and its phy layer security implications

In this work, a novel near optimal seed based random interlcaver is designed. An optimal interleaver scatters a given burst of errors uniformly over a fixed block of data -a property that is measured by so called 'spread'

Fabrication and characterization of curcumin loaded ZnO nanoparticles and their in vitro antibacterial activity

Nanotechnology is broadly defined as the study and development of the chemical physical and natural properties of materials, devices, and structures that differ from those found on a larger scale, and Nano patents are derived from the Japanese language. Zinc oxide nanoparticles are used in a wide-ranging applications, visible light, catalytic actions, ultrasonic, deodorizing, diabetes treatment, cosmetics, lasers, paints, ultraviolet light absorbing constituents, rubber industry, catalytic agent for light flattening, and specifically in the medical and pharmaceutical sciences7. Curcumin is a useful plant-based material derived from "turmeric" that has the potential to be used in the green synthesis of ZnONPs. This is due to the influence of "polyphenol," which may also result in the formation of ZnONPs during the reduction process. Characterization reported Spherical particles with varying size from few nanometers to about 900 nm. The antibacterial activity by disk diffusion method against E. coli (Gram negative), Pseudomonas aerugionsa, Bordetella bronchiseptics & Micrococcus luteus revealed mark able zone of inhibition that declared potent antibacterial activity of Curcumin ZnO NP against gram positive bacteria more than negative ones where Ciprofloxacin was used as standard

Students’ Passion for Grades in Higher Education Institutions in Pakistan

AbstractThe shrinking labour market and employers’ obsession for talent have increased the challenges for students in universities to achieve higher academic grades for improved employability. Researchers have suggested different factors that contribute towards students’ enthusiasm for grades during the educational career. The focus on this phenomenon in higher education has so far been restricted to developed countries. The purpose of this study is to investigate empirically the predictors of students’ passion for university grades in institutions of higher education in Pakistan in a milieu of dwindling job opportunities under prevailing economic environment.The study is based on primary data, collected through a structured questionnaire from 242 students studying in higher-education institutions. Factor analysis, correlation and regression analyses were used to determine the effects of pressure for employability, academic self-concept, parental interest, psychological pressure, academic recognition, and financial concerns on students’ passion for academic grades.The study revealed that pressure for employability; academic self-concept, academic recognition, parental concern, and psychological pressure were the main predictors of students’ passion for academic grades. Financial concerns did not indicate a statistically significant effect on criterion variable. The study provides useful insight to policy makers in higher education institutions to formulate appropriate academic interventions to foster students’ endeavours to excel in learning pursuits

Dispositional and Situational Antecedents of Consumer’s Impulse Buying Behavior

Impulse buying is a well-known fact. With the increase in internet users and growth in e-commerce, consumers have more opportunities for impulse buying. Over $4 billion US economy is based on impulse buying. This study explored the direct and indirect effects of dispositional variables (Impulse buying tendency, Shopping excitement trait and Lack of self-control) and situational variables (Time availability and Money availability) on consumers’ impulse buying behavior. Moreover, the mediation role of impulse buying tendency between dispositional and impulse buying behavior, and situational variables and impulse buying behavior has also been analyzed. The hypotheses were tested using partial least square-structural equation modeling (PLS-SEM). The results confirmed the direct effects of antecedents on impulse buying behavior. Whereas, the mediation role of impulse buying tendency is only confirmed between shopping excitement trait and impulse buying behavior. The findings have important managerial implications. Keywords: dispositional, situational, impulse buying, impulse buying tendency, lack of self-control DOI: 10.7176/EJBM/11-1-1

A Novel Seed Based Random Interleaving for OFDM System and Its PHY Layer Security Implications

Wireless channels are characterized by multipath and fading that can often cause long burst of errors. Even though, to date, many very sophisticated error correcting codes have been designed, yet none can handle long burst of errors efficiently. An interleaver, a device that distributes a burst of errors, possibly caused by a deep fade, and makes them appear as simple random errors, therefore, proves to a very useful technique when used in conjunction with an efficient error correcting code. In this work, a novel near optimal seed based random interleaver is designed. An optimal interleaver scatters a given burst of errors uniformly over a fixed block of data - a property that is measured by so called ‘spread’. The design makes use of a unique seed based pseudo-random sequence generator or logistic map based chaotic sequence generator to scramble the given block of data. Since the proposed design is based on a seed based scrambler, the nature of input is irrelevant. Therefore, the proposed interleaver can interleave either the bits or the symbols or the packets or even the frames. Accordingly, in this work, we analyze the suitability of interleaver when introduced before or after the modulation in single carrier communication systems and show that interleaving the bits before modulation or interleaving the symbols after modulation has same advantage. We further show that, in an orthogonal frequency division multiplexing (OFDM) systems, the position of interleaver, whether before or after constellation mapper, has no significance, and is interchangeable. However, scrambling symbols is computationally less expensive than scrambling bits. For the purpose of analyzing the performance of the proposed seed based random interleaver, simulations are carried out in MATLAB®. Results show that our proposed seed based random interleaver has near optimal properties of ‘spread’ and ‘dispersion’. Furthermore, the proposed interleaver is evaluated in terms of bit error rate (BER) versus length of burst error in a single carrier system both before and after modulation. The proposed interleaver out-performs the built in RANDINTLV in MATLAB® when used in the same system. It shows that proposed interleaver can convert greater amount of burst errors into simple random errors than that of MATLAB® interleaver. The proposed interleaver is also tested in IEEE 802.16e based WiMAX system with Stanford University Interim (SUI) channels to compare the performance of average BER versus SNR for both pre modulation and post modulation interleaver. Results show that pre modulation interleaver and post modulation has same performance. There is also a side advantage of this seed based interleaver, in that it generates a variety of unique random-looking interleaving sequences. Only a receiver that has the knowledge of the input seed can generate this sequence and no one else. If the interleaving patterns are kept secure then it can possibly be used to introduce an extra layer of security at physical (PHY) layer. In that way, at PHY layer, one builds an additional entry barrier to break through and it comes with no extra cost. This property has been investigated by carrying out key sensitivity analysis to show that the attacks to guess key can be very futile, as difference at 4th decimal place in the initial condition can lead to entirely different scrambling

Framework for Content Distribution over Wireless LANs

Wireless LAN (also called as Wi-Fi) is dominantly considered as the most pervasive technology for Intent access. Due to the low-cost of chipsets and support for high data rates, Wi-Fi has become a universal solution for ever-increasing application space which includes, video streaming, content delivery, emergency communication, vehicular communication and Internet-of-Things (IoT). Wireless LAN technology is defined by the IEEE 802.11 standard. The 802.11 standard has been amended several times over the last two decades, to incorporate the requirement of future applications. The 802.11 based Wi-Fi networks are infrastructure networks in which devices communicate through an access point. However, in 2010, Wi-Fi Alliance has released a specification to standardize direct communication in Wi-Fi networks. The technology is called Wi-Fi Direct. Wi-Fi Direct after 9 years of its release is still used for very basic services (connectivity, file transfer etc.), despite the potential to support a wide range of applications. The reason behind the limited inception of Wi-Fi Direct is some inherent shortcomings that limit its performance in dense networks. These include the issues related to topology design, such as non-optimal group formation, Group Owner selection problem, clustering in dense networks and coping with device mobility in dynamic networks. Furthermore, Wi-Fi networks also face challenges to meet the growing number of Wi Fi users. The next generation of Wi-Fi networks is characterized as ultra-dense networks where the topology changes frequently which directly affects the network performance. The dynamic nature of such networks challenges the operators to design and make optimum planifications. In this dissertation, we propose solutions to the aforementioned problems. We contributed to the existing Wi-Fi Direct technology by enhancing the group formation process. The proposed group formation scheme is backwards-compatible and incorporates role selection based on the device's capabilities to improve network performance. Optimum clustering scheme using mixed integer programming is proposed to design efficient topologies in fixed dense networks, which improves network throughput and reduces packet loss ratio. A novel architecture using Unmanned Aeriel Vehicles (UAVs) in Wi-Fi Direct networks is proposed for dynamic networks. In ultra-dense, highly dynamic topologies, we propose cognitive networks using machine-learning algorithms to predict the network changes ahead of time and self-configuring the network

A novel seed based random interleaving for OFDM system and its phy layer security implications

In this work, a novel near optimal seed based random interlcaver is designed. An optimal interleaver scatters a given burst of errors uniformly over a fixed block of data -a property that is measured by so called 'spread'

Contemporary challenges confronting Islamic banking & finance

The philosophy of Islamic economics is "brining economics in consonance with Shariah", guiding Islamic banking and finance to abolish interest from operations, has reported a monumental growth, envisaged the most lucrative and unsusceptible segment of the economy. Islamic finance is undoubtedly flourishing worldwide entails trajectory development but at other front it encounters a number of impediments in development since its inception. The emphasis of this study is to encapsulate in tabular form, the contemporary problems and challenges Islamic finance has encountered during the span of last 28-years from 1988 to 2015. The austere Shariah compliance; regulatory and prudential challenges; misconception among western society about Islamic banking philosophy; unavailability of money and capital market for scant Islamic financial instruments; piercing competition; privation of Islamic banking and finance awareness; absence of uniform reporting standards; complexities of regulatory and supervisory issues; lack of central supervisory body, governance and dearth of consensus among Shariah scholars been the precarious challenges among many others. A unified central regulatory and supervisory mechanism required in converging sprinkled Islamic finance practices and to foster a synchronized and standardized regulatory framework consensus need to be developed among all Shariah scholar