Islamabad, Pakistan
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Ahmed M.,COMSATS Institute of Information Technology | Riaz K.,COMSATS Institute of Information Technology | Maqbool Khan A.,International Islamic University, Islamabad | Bibi S.,Preston University
Renewable and Sustainable Energy Reviews | Year: 2015

A recent survey of energy-growth literature has highlighted the potential trade-off between bivariate models that suffer from omitted variable bias, and the danger of over-parameterization of multivariate models in the individual country setting (Narayan and Smyth [2]). This is a serious limitation when the interest is in drawing policy implications for specific countries with short times series of available data. The maximum entropy bootstrap approach was used to re-examine the nature of causal relationship between energy consumption and economic growth for Pakistan where the available time series data was only from 1971 to 2011. Unlike the techniques used in much of the earlier literature, this approach does not rely on asymptotic methods and, therefore, leads to robust inference even in small samples. Moreover, the approach can be applied in the presence of non-stationarity of any type, and structural breaks, without requiring data transformation for to achieving stationarity, and is not sensitive to specification errors such as those in lag length selection. The empirical findings, based on both the bivariate as well as the multivariate frameworks, supported the conservation hypothesis, implying the existence of a unidirectional causality from economic growth to energy consumption. © 2015 Elsevier Ltd.

Zafar L.,University Of Kashmir | Hadi F.,Preston University
Lecture Notes in Electrical Engineering | Year: 2015

Wireless Mesh Networks (WMNs) are the robust and flexible networks having redundant links. These networks have some fixed nodes (gateways) providing the internet connectivity and having some static or mobile clients. However, WMNs has some security issues that have not been addressed by the existing standards. We proposed an enhanced authentication mechanism for the security of group heads in group communication. We propose and analyze an enhanced reliable authenticated group head communication (ERAGHC) architecture for secure reliable group head communication and to increase the overall efficiency and performance of architecture. The scenario has been developed and implemented in OMnet++ simulator. The simulation results reveal that the ERAGHC is better than the previous schemes in term of packet delivery ratio, packet delay and overall efficiency. © Springer-Verlag Berlin Heidelberg 2015.

Khan M.,Preston University | Rahman A.U.,Bahria University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In the past few years the World Wide Web has become a platform for news publication. Many magazines and newspapers have stopped publishing news on paper and only publish their digital versions. This paper presents a proposal for preserving news stories related to the same topic but published in various newspapers. © Springer International Publishing Switzerland 2015.

Ahmadmir N.,Preston University | Ullah R.,COMSATS Institute of Information Technology
Tamkang Journal of Mathematics | Year: 2011

In this paper, we establish some inequalities of Ostrowski and Grüss type for triple integrals on arbitrary time scales involving three functions and their partial derivatives. We also discuss the discrete Ostrowski and Grüss type inequalities for triple sumon time scale.

Momein F.A.,Preston University | Brohi M.N.,United Arab Emirates University
Asian Journal of Information Technology | Year: 2010

Crime is a social phenomenon that has existed throughout human history. As people and technology evolved and developed new technology, there is no doubt that criminals continue to exploit or take advantage of this technological progress. We are now in the era of an information revolution, which provides modern science, high technology and accordingly, it is axiomatic that new types of crimes have come to the forefront. The criminal of yesterday is exactly like the criminal of today and therefore, the crime of yesterday is certainly not like the crime of today. © Medwell Journals, 2010.

Habib D.,Quaid-i-Azam University | Chaudhary M.F.,Preston University | Zia M.,Quaid-i-Azam University
Applied Biochemistry and Biotechnology | Year: 2014

Here, we demonstrate the micropropagation protocol of Argyrolobium roseum (Camb.), an endangered herb exhibiting anti-diabetic and immune-suppressant properties, and antioxidant enzymes pattern is evaluated. Maximum callogenic response (60 %) was observed from leaf explant at 1.0 mg L-1 1-nephthalene acetic acid (NAA) and 0.5 mg L-1 6-benzyl aminopurine (BA) in Murashige and Skoog (MS) medium using hypocotyl and root explants (48 % each). Addition of AgNO3 and PVP in the culture medium led to an increase in callogenic response up to 86 % from leaf explant and 72 % from hypocotyl and root explants. The best shooting response was observed in the presence of NAA, while maximum shoot length and number of shoots were achieved based on BA-supplemented MS medium. The regenerated shoots were rooted and successfully acclimatized under greenhouse conditions. Catalase and peroxidase enzymes showed ascending pattern during in vitro plant development from seed while ascorbate peroxidase showed descending pattern. Totally reverse response of these enzymes was observed during callus induction from three different explants. During shoot induction, catalase and peroxidase increased at high rate while there was a mild reduction in ascorbate peroxidase activity. Catalase and peroxidase continuously increased; on the other hand, ascorbate peroxidase activity decreased during root development and acclimatization states. The protocol described here can be employed for the mass propagation and genetic transformation of this rare herb. This study also highlights the importance and role of ascorbate peroxidase, catalase, and peroxidase in the establishment of A. roseum in vitro culture through callogenesis and organogenesis. © 2013 Springer Science+Business Media New York.

Rizvi Z.F.,Quaid-i-Azam University | Mukhtar R.,Quaid-i-Azam University | Chaudhary M.F.,Preston University | Muhammad Z.,Quaid-i-Azam University
Pakistan Journal of Botany | Year: 2013

Three medicinally important plants Lawsonia inermis, Lantana camara and Swertia angustifolia were evaluated for their antibacterial and antifungal activities. L. inermis extract showed maximum activity against staphylococcus aureus and Klebsiella pneumoniae. L. camara extract was not much active against any bacterial strain. A range of zone of inhibition 9- 12.3 mm was observed against all bacterial strains tested. S. angustifolia did not show activity against any bacterial strain. In case of fungal growth inhibition L. inermis showed good inhibition of 3 fungal strains Fusarium solani, Alternaria and Mucor. The percent inhibitions were 78.8, 65.3 and 71.1, respectively. These findings demonstrate that L. inermis is a good candidate for further studies that carries both antibacterial and antifungal active constituents.

Rizvi S.S.,Preston University | Chung T.-S.,Ajou University
International Review on Computers and Software | Year: 2013

The continuous improvement in hardware design and advances in wireless communication have enabled the deployment of various wireless applications. Wireless sensor network applications become essential tools for monitoring the activity and evolution of our surrounding environment. However, the wireless sensor nodes are highly resource constrained in terms of limited processing speed, run time memory, persistent storage, communication bandwidth and finite energy. Therefore, for energy efficient in-network data retention and query processing, data mining approach is highly required that reduces the storage space, energy and communication cost consumption. This paper investigates the data mining approach for clustering sensor networks. Results show 99.88% less storage space, 37.6% reduced energy and 80% increased query throughput is achieved using data mining approach for wireless sensor networks. © 2013 Praise Worthy Prize S.r.l. - All rights reserved.

Rizvi S.S.,Preston University | Chung T.-S.,Ajou University
International Review on Computers and Software | Year: 2012

Wireless sensor network applications become essential tools for monitoring the activity and evolution of our surrounding environment. Since, the key characteristics of wireless sensor networks are to handle very sensitive real-time tasks like surveillance and target tracking, the performance of processing devices within sensor nodes highly impact the significance of overall network. Performance mainly depends on the physical architecture of any processing system. There are two well known architectures for microprocessors: von Neumann and Harvard. In this paper, we analyze, evaluate and compare the architectures to investigate the quality in terms of query optimization, power consumption and peripherals utilization in resource constraint data centric wireless sensor networks. Experimental results based on index structures like B-tree, R-tree, and MR-tree are provided and discussed to give the better idea to users for suitable innetwork data processing products for their real-time systems. © 2012 Praise Worthy Prize S.r.l. -All rights reserved. - All rights reserved.

Rizvi S.S.,Preston University | Chung T.S.,Ajou University
International Journal of Distributed Sensor Networks | Year: 2012

Flash memory has become a more widespread storage medium for modern wireless devices because of its effective characteristics like nonvolatility, small size, light weight, fast access speed, shock resistance, high reliability, and low power consumption. Sensor nodes are highly resource constrained in terms of limited processing speed, runtime memory, persistent storage, communication bandwidth, and finite energy. Therefore, for wireless sensor networks supporting sense, store, merge, and send schemes, an energy efficient and reliable database-based query optimization technique is highly required with consideration of sensor node constraints. Databases on hard disk drives perform data storage and retrieval using index structures which are still not practiced for sensor devices. In this paper, we evaluate different indices like B-tree, R-tree, and MR-tree by implementing them on log structured external NAND flash memory-based advanced file systems for supporting energy efficient data storage and query optimization from flash based data centric sensor devices in wireless sensor networks. Experimental results show that PIYAS (Rizvi and Chung, 2010) file system along with B-tree indexing deployed on flash memory MLC gives the significant performance in respect of high query throughput optimization and less resources consumption for wireless sensor devices. © 2012 Sanam Shahla Rizvi and Tae Sun Chung.

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