International Journal of Computer and Applications

The Semantic Web 10

2009 International Conference on Future Computer and Communication

being used in many other applications to explicitly declare the knowledge embedded in them. However, not only are ontologies useful for applications in which knowledge plays a key role, but they can also trigger a major change in current Web contents. This change is leading to the third generation of the Web—known as the Semantic Web—which has been defined as “the conceptual structuring of the Web in an explicit machine-readable way.”1 This definition does not differ too much from the one used for defining an ontology: “An ontology is an explicit, machinereadable specification of a shared conceptualization.”2 In fact, new ontology-based applications and knowledge architectures are developing for this new Web. A common claim for all of these approaches is the need for languages to represent the semantic information that this Web requires—solving the heterogeneous data exchange in this heterogeneous environment. Here, we don’t decide which language is best of the Semantic Web. Rather, our goal is to help developers find the most suitable language for their representation needs.

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Ontology languages for the Semantic Web

A massive release of harmful substances especially heavy metal ions and dyes to the environment has been a major concern due to many people disregards the proper protocols in the waste management. The freshwater supplies are threatened and huge discharge of pollutants result from various anthropogenic activities may pose a major threat to the living organisms and negatively affect the ecosystem stability. This article reviews the development of magnetic iron oxide nanocomposites for removal of heavy metal ions and dyes from water. The highlight will be focused on current research activities for controlled size and dispersion of magnetic iron oxide nanoparticles within solid matrices including zeolites, silica, clays, carbon, activated carbon, graphene and graphene oxide. The magnetic properties of the nanocomposites will be evaluated to determine whether they possessed sufficient magnetization for easy separation by an external magnet. The unique features of the synthesized materials will be investigated along with their application in the removal of heavy metal ions and dyes. The advantages and limitations of the magnetic nanocomposites will be highlighted to determine their adsorption ability. The effect of various parameters such as pH, contaminants concentration, adsorbent dosage, contact time and temperature will be summarized to identify the best condition for effective pollutants removal.

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Solid matrices for fabrication of magnetic iron oxide nanocomposites: Synthesis, properties, and application for the adsorption of heavy metal ions and dyes

Recent advances in mobile technologies have emerged new challenges for researchers. File management and retrieval on resource-limited devices has become a challenging problem as these devices are now equipped with larger storage capacities. This paper presents an overview about the possibilities of implementing Semantic Web Technologies in order to facilitate the file retrieval on resource-limited devices. We have proposed a semantic based file retrieval framework which utilizes a generic ontology in file search process. The search module is implemented in Java ME platforms as a case study. Performance of the proposed search module is evaluated through experimental tests along with probabilistic evaluations. The implemented module not only automates file retrieval process but also shows significant improvement in file retrieval efficiency by utilizing the knowledge of employed ontology in the search module.

Ontology based file retrieval framework for resource limited mobile devices

In this paper, we investigate a campus wide Wireless Local Area Network (WLAN) over a period of one month with the help of an advanced training system. Traffic characteristics and analysis has been performed based on the users` connectivity and their traffic behavior in a WLAN environment. The obtained results predict the users` traffic intensity in different time slots of the day and different days of the week. Moreover, traffic intensity and available bandwidth of each Access Point (AP) in the WLAN has been investigated.

Analysis of campus wide Wireless LAN using an advanced training system

Many relay selection algorithms have been suggested in the last few years. In this paper, we propose Fuzzy Logic based relay selection algorithm using three different parameters. Amplify and Forwardrelaying scheme has been used where required parameters for the proposed algorithm are relay residual power, SNR and traffic. With the considered parameters, the system achieves efficiency in terms of relay's life time, processing time and communication overhead. The simulation results show that the proposed system makes a better and effective selection of relay in dual hop network.

A Fuzzy Logic based best relay(s) diversity selection in dual-hop networks

In this paper, we propose a new multi-node relay network, that works on the Amplify-and-Forward protocol, to select the most optimal path towards the destination; thus adaptively setting the number of relays to be involved in the cooperation. Nakagami-2 fading channel is considered in the modeling and Instantaneous channel state information (CSI) from the destination is used as the selection criteria at the relays. Locations of the relays and distances between them are taken into account for an improved signal to noise ratio (SNR) with reduction in the bit error rate (BER). Moreover, spatial diversity is applied on the destination using maximal ratio combining (MRC). An analysis of the different spatial diversity techniques is done to find the best suited technique and simulation results for a much less BER over a 106 number of symbols in the input is presented.

Adaptive relay selection technique for cooperative network over Nakagami fading channels

This paper conducts the comparative study of cooperative cognitive radio networks using Decode and Forward (DF) protocol at the relays. The aim of the study is to decrease the uncertain noise along with provision of efficient energy detection technique. Moreover, the detection accuracy and capability of the network in AWGN channel has been investigated by the addition of path loss effect. Multiple relays are used in different scenarios considering distances from source and destination. Path loss exponent is set as 3 and Monte Carlo simulations are performed for the desired results. The proposed system has been evaluated based on the Detection Probability (Pd), Unavailable Probability (Pna) and Collision Probability (Pc).

Sadaqat Jan

Papers

Ontology based file retrieval framework for resource limited mobile devices

Analysis of campus wide Wireless LAN using an advanced training system

A Fuzzy Logic based best relay(s) diversity selection in dual-hop networks

Adaptive relay selection technique for cooperative network over Nakagami fading channels

Performance analysis of two-relay cooperative cognitive network with path loss effect