Showing papers by "Muhammad Younas published in 2011"

Metal-semiconductor transition in NiFe2O4 nanoparticles due to reverse cationic distribution by impedance spectroscopy

Abstract: We have investigated the magnetic and electrical response of the sol-gel synthesized NiFe2O4 nanoparticles. Changes in the impedance plane plots with temperature have been discussed and correlated to the microstructure of the material. Thermally activated hopping carriers between Fe3+-Fe2+ and Ni2+-Ni3+ ions have been determined for a decrease in the resistance of the sample and a change in the conduction mechanism around 318 K. The mixed spinel structure and broken exchange bonds due to small size effects are due to the canted spin structure at the surface of the nanoparticles. The magnetization is found to be influenced by the surface spin canting and anisotropy. We have established the semiconducting to metallic transition (SMT) temperature to be around 358 K in terms of localized and delocalized eg electrons along with a transition from less conductive [Fe3+–O2−–Fe3+] and [Ni2+–O2−–Ni2+] linkage to more conductive [Fe3+–Fe2+] and [Ni2+–Ni3+] linkage at the octahedral B site. A decrease in the dielectr...

Colossal resistivity with diminished tangent loss in Zn-Ni ferrite nanoparticles

Abstract: We have investigated the electrical and magnetic response of the sol‐gel synthesized ZnxNi1−xFe2O4 (x = 0.0, 0.5 and 1) nanoparticles. The ratio of A-site sextet intensity to that of B-site sextet is featured in terms of divergence in coordination of Fe 3+ ions from four-fold (A-site) to six-fold (B-site). Canted spin structure and weakening of Fe 3+ (A)‐Fe 3+ (B) interactions at the surface of the nanoparticles assign the reduced value of room temperature magnetization in these nanoparticles. Shift of the blocking temperature with Zn content is ascribed to the change in the magnetic anisotropy. Colossal resistivity and reduced dielectric constant are discussed on the basis of dangling bond, superparamagnetic character, canted spin structure and polarizability of the cations. Diminished tangent loss is stipulated in terms of decrease in magnetocrystalline anisotropy and collapse of long-range magnetic order. We report colossal resistivity (i.e. 3.15 × 10 9 � cm), reduced dielectric constant (3.97) and diminished tangent loss (0.07) for Ni0.5Zn0.5Fe2O4 nanoparticles. (Some figures in this article are in colour only in the electronic version)

Semantic-ART: a framework for semantic annotation of regulatory text

Abstract: Converting regulatory texts to machine interpretable models can enhance the automation of compliance management (CM) processes. The process poses serious research challenges as the information to be extracted from the regulatory texts comes from different regulatory bodies and is in different formats. In this paper, we present the main problems that we have faced in this area and how we have tackled them. Our proposed framework, Semantic-ART, considers the use of semantic annotation (SA) techniques to extract the regulations automatically.

A new model for context-aware transactions in mobile services

Abstract: With the ubiquity of handheld devices (such as smart phones and PDAs) and the availability of a wide range of mobile services (such as mobile banking, road traffic updates, and weather forecast), people can nowadays access information and conduct online transactions virtually anywhere and anytime. In such flexible, dynamic but less reliable environment, transaction management technology is believed to provide service reliability and data consistency. Indeed, in mobile and ubiquitous environments where devices as well as services can seamlessly join and leave the ubiquitous network; transaction management can be very helpful during the recovery of services from failure. Current transaction models and commit protocols do not take into account context information. However, in mobile environments, it is imperative to consider context information in the commit of a transaction--i.e., a transaction can be successfully completed if it meets the required context. In this paper, we propose a new model for context-aware transactions and their performance management in mobile environments. Unlike conventional transactions, context-aware transactions adapt to the required context. By context, we mean the service's context as well as the users' context that includes users' needs and preferences. This paper designs and develops the proposed transaction model and evaluates its performance in terms of time and message complexities as well as transaction's throughput.

Towards semantic methodologies for automatic regulatory compliance support

Abstract: Businesses and organizations must comply with requirements and expectations such as regulations, policies, mandates and guidelines to meet public standards and avoid hefty penalties. Checking compliance manually is a laborious, extensive and error-prone process. The problems in the process are, to some extent, alleviated by using computerized compliance management systems. However, these systems are experiencing challenges in coping with the frequent changes and updates in the regulations. This paper describes our research on the use of semantic web technologies to support compliance management. In particular, we propose a methodology, RegCMatic that supports the management of the compliance system. Its originality lies on automating the extraction of regulatory information from regulatory texts, and mapping regulations to organizational internal processes. Our proposed methodology is applied to the Pharmaceutical industry, where regulatory information is extracted from the Eudralex EU regulation and modeled using a semantic formalism.

A Framework to Test Advanced Web Services Transactions

Abstract: Transactions are a key issue in the reliability of distributed applications because they ensure all the participants achieve a mutually agreed outcome. However, current research has given little attention to testing transactions in web services. This paper presents a conceptual framework, inspired in risk-based methodologies, to address this gap. It also reports on preliminary results and identifies future work.

An Abstract Transaction Model for Testing the Web Services Transactions

Abstract: Transactions are a fundamental technology for building efficient and reliable web service based applications. Various models and protocols have been developed by academic and industrial research community in order to effectively manage web services transactions. We propose a novel abstract model for dynamically modeling distinct web services transaction protocols. Model-based testing techniques can be used on the abstract model in order to automatically generate test scenarios.

A Generic Approach to the Services Delivery in Enterprise eBusiness Platforms

Abstract: The contemporary business environment can be seen as a logical effect of eBusiness, advanced integrated networks, and software services. In such an environment application deployment models have revolutionized the way businesses interact, collaborate and transact with customers, suppliers, partners, employees and shareholders. The purpose of our work is to develop a generic model for performance analysis of software services in order to facilitate enterprises to attach their customers more tightly by an effective service delivery which in turn optimizes business processes at different steps. This communications enablement allows not only greater synergy and velocity among vendors, suppliers and partners within the value creation and delivery chain of the business, but also, creates responsive and seamless customer service.

Ambient networks and services

Abstract: Ambient networks are considered as modern mobile networks that involve heterogeneous mobile devices, networks and users. The distinguishing feature of ambient networks is that they allow for dynamic composition of different networks, systems and services. Such composition enhances the capability of networks and also provides services that suit the users and the network environments. The research community has actively investigated the underlying challenges pertaining to these networks, as they fundamentally differ from the classical problems due to their inherent constraints. The theme of this special issue is to present latest research on ambient networks, systems and services. This special issue includes a selection of papers from an open call as well as selected papers from the International Conference on Ambient Systems, Networks and Technologies (ANT 2010) which was held in November 2010 in Paris, France and has attracted excellent scientific papers contributing to the state of the art in this research field. All the papers were subjected to a two rounds of rigorous review process. Based on the reviews, a total of seven papers were selected for publication. These papers present interesting research work on ambient networks and intelligence, wireless and sensor networks, and mobile services and applications. Self-organisation is an important research issue in ambient networks. Habib and Marimuthu exploit molecular biology assembly techniques in the self-organisation of ambient networks. This approach analogizes the ambient network nodes as molecules in order to form clusters of such nodes in a self-organised manner. Clusters are formed by defining pair-wise relations between nodes such as the distance, incoming traffic and outgoing traffic. Depending on the type of relationship, nodes attract (or repulse) each other to (from) the cluster. The experimental results show that the proposed approach significantly optimises backbone traffic. The paper by Buchmayr and Kurschl surveys the existing projects and developments in the situationaware ambient intelligence. The aim of the survey is to establish the knowledge and understanding of the large number of prototypes and working systems that have been developed for situation-aware ambient intelligence. Based on the survey, this paper designs a reference architecture and also develops an evaluation criteria for situation awareness in ambient systems. The survey also identifies open research issues for new research projects in the area of ambient intelligence. Becerra and Kremer propose a multi-agent approach in order to design an ambient intelligent environment. This work considers an interesting application area wherein agents are used to represent and control various inhabitants such as humans, animals, plants and objects such that they can sacrifice their own needs for the benefit of the whole environment. For instance ‘‘a dark room could prevent the plants from growing; a cold room would make the leather sofa uncomfortable to sit on when the man returns; E. Shakshuki (&) Jodrey School of Computer Science, Acadia University, Wolfville, Canada e-mail: elhadi.shakshuki@acadiau.ca

Phylogenetic Analysis of First Generation Cotton Leaf Curl Virus (CLCuV) Resistant Cotton Varieties

Abstract: Cotton is a major cash crop of Pakistan. During the last few years, cotton production has been hampered by cotton leaf curl virus (CLCuV) disease. Cotton breeders successfully combated CLCuV by developing resistant varieties, however it resurfaced in 2001, all the varieties proving susceptible. This study was conducted to explore the genetic diversity among cotton varieties approved as first defense line against CLCuV using DNA markers. The four cotton varieties, CIM-448, CIM-1100, FH-900 and FH-901, were subjected to random amplified polymorphic DNA (RAPD) and simple sequence repeats (SSR) finger printing assay to reveal genetic relatedness. A total of 110 RAPD primers were surveyed out of which 16 were found polymorphic. The size of 449 amplified loci ranged from 250 to 1500 bp with an average of 4.08 loci per primer. Similarity matrix revealed 96% similarity among the varieties assayed. For SSR genetic analysis, 92 primer pairs were surveyed and only six primers were found informative. A total ...