Sherif G. Aly

Interest aware PeopleRank: Towards effective social-based opportunistic advertising

Various emerging context aware social-based applications and services assume constant non-disruptive connectivity. Mobile advertisers in such environments want to reach potentially interested users in a given proximity and within a specified short-duration, whether these users are connected to the network or not. While opportunistic forwarding algorithms can be leveraged for forwarding these advertisements, there is little incentive for those not interested in the ad to act as forwarders. Our goal in this paper is to leverage explicit interest, gathered from a users social profile, and integrate it with social-based opportunistic forwarding algorithms in order to enable soft realtime opportunistic ad delivery in intermittently connected mobile networks. We propose IPeR, a fully distributed interest-aware forwarding algorithm that integrates with PeopleRank to reduce the overall cost and delay while reducing the number of contacted uninterested candidates. Our results, obtained via simulations and validated with real mobility traces coupled with user social data, are promising. In comparison to interest-oblivious socially-aware protocols such as PeopleRank, the IPeR approach reduces the cost to 70% to reach the same delivery ratio, and reduces the ratio of contacted uninterested forwarders by 23%. It also achieves an extra 70% recall and 107% accuracy with only 2% less precision.

Sustained service lookup in areas of sudden dense population

As mobility became the norm rather than the exception, location-based services are playing more of a key role in assisting mobile users. In this paper, we address the challenges of providing location-based services to users in areas of sudden population increases, such as stadiums and traffic jams. A sudden increase in the number of mobile users leads to an increasing demand for the already scarce wireless bandwidth, thus causing dramatical throughput degradation and an increase in connectivity failures. We propose a hybrid model within which a peer-to-peer mode is deployed to assist the cellular-based network whenever a sudden increase in population density is sensed by the base station. Location-based data is migrated to selected elite nodes, thus allowing other peer nodes to get their information locally. This approach is proven, through experimental results, to decrease the query response time and number of query failures. Copyright

PIPeR: Impact of power-awareness on social-based opportunistic advertising

Interest and social-awareness can be valuable determinants in decisions related to content delivery in mobile environments. Under certain conditions, we can deliver content with less cost and better delivery ratios, while only involving users that are interested in the type of content being delivered. However, the depletion of valuable power resources poses a deterrent to node participation in such interest-aware forwarding systems. No significant research contribution has been identified to collectively maximize the benefits of social, interest, and power awareness. In this work, we propose a new algorithm called PIPeR which integrates power awareness with an interest and socially aware forwarding algorithm called IPeR. Through simulations, we present and evaluate four modes of PIPeR. The results show that PIPeR is more fair and preserves at least 22% of the power IPeR consumes with less delay, while relying significantly on interested forwarders and with comparable cost to maintain similar delivery ratios.

Cooperative web caching of dynamic web content

Web caching is one of many applications argued to benefit from a switch from a client-server to a peer-to-peer architecture. Several projects suggested the use of a network of peers to provide cached web content in order to help sites survive a burst of user requests. We present a new system that targets web sites with dynamic content and allows them to use a group of a variable number of volunteer peers to provide cached web content to the clients. The main objective of our system is to increase the capacity of a web server, and to reduce the average end user latency. We implement an Internet forums application using our approach as a case study of dynamic web sites, and emulate the implementation on a single machine. We show and analyze the results of experiments we applied on the emulated system, focusing on measurements of average end user latency and the upload bandwidth used by the web server.

The Context Oriented Architecture: Integrating Context into Semantic Web Services

While emerging standards promote the interoperability of Web services, Web services adaptability to user and application context is a requirement yet to be investigated. Web services today encapsulate application and business logic and are candidates for supporting pervasive environments, where adaptability will have added value in all of these domains. In this paper we introduce the context oriented architecture; an architecture for building context aware applications using Web services as building components. The context oriented architecture uses semantic description to automate monitoring and responding to service context. We extend the specifications and implementation of the semantic Web service ontology language (OWL-S) to represent the context profile of a Web service

Rethinking opportunistic routing using space syntax

Communication in mobile opportunistic networks is primarily achieved through a variety of store-carry-and-forward techniques, where node mobility is exploited for end-to-end data delivery. The main routing challenges these networks face is determining when to forward a message and which nodes to forward it to, ultimately resulting in varying delay and cost trade-offs. Routing solutions to date heavily rely on assumptions regarding the underlying environment and node capabilities, which may be unrealistic in many cases. In this paper, we propose building upon Space Syntax in order to make forwarding decisions with more realistic assumptions about the underlying environment. Space Syntax metrics have long been used in the field of architecture to model natural mobility patterns by analyzing spacial configurations. To adapt Space Syntax to opportunistic routing, we propose our popularity index metric, which is based on core Space Syntax metrics. This popularity index depends on factors in the environment that do not frequently change, and therefore, can be more realistically adopted and deployed when compared to other opportunistic routing algorithms. We introduce two simple forwarding algorithms based on the popularity index and compare their performance to other approaches. Our initial evaluation shows that Space Syntax based routing performs relatively well compared to state-of-the-art solutions with the added advantage of being more realistic and as a result easier to deploy.

The Context Oriented Architecture: An Augmentation of Context Awareness and Reactivity into Web Services

Standardization promotes web services as a very promising candidate for successfully integrating disparately heterogeneous systems. As such, web services prove themselves to be very suitable candidates for supporting the predominantly heterogeneous pervasive environments. The ability of web services however to sense their surrounding context and effectively react to it is still a matter of research. In this work, we introduce a new architecture, an architecture solely built on open standards, that supports the development of context aware and context reactive applications that use web services as building components. We describe in detail the various components of this architecture, along with their supporting interactions. Furthermore, we describe the expansion of the OWL-S ontology language, namely expanding both the profile and the process model ontologies, to allow for encoding context behavior of both web services and clients. We eventually illustrate validation scenarios for this architecture, and demonstrate an application example built using this architecture that adapts to ambient security requirements.

The Use of Social Context to Enhance Mobile Web Search Experience

Web access, especially through search, is by far one of the most popular operations performed on mobile devices. It is very interesting how the Mobile and Social worlds have significantly converged in many interesting ways, the least of which is the ability to simply access social networks on the move. However, much literature indicates how search results, and in specific mobile search is far from satisfactory in terms of meeting user intent and need. This has ultimately led to the introduction of context-aware web search to obtain more adequate results. In this research, we focus on using social context obtained from user social networks to refine search queries. Our initial target is to propose a system that will ultimately demonstrate the effectiveness of integrating this type of context when conducting mobile search. We also describe how we will utilize this system to classify user queries issued on mobile devices to determine the degree by which social context used, to then reformulate the queries by augmenting relevant context, and then finally ranking the results to match user needs.

Summarizing Online Discussions by filtering posts

In this paper, we attempt to summarize online discussions by filtering posts. Selecting the highly related posts from the discussion boards leads to a summarized version of the discussion. Online Discussion Summarizer (ODS) is based on unsupervised information retrieval techniques. Four features are used in the summarization function; which are the term frequency inverse post frequency, title term frequency, description term frequency and author reputation. This paper shows that combining the four features in the same function results in higher accuracy than using each alone. ODS was able to summarize online discussions with an accuracy of 72%, precession of 83% and recall of 62%.

Aspectizing Database Connection Pooling for Improved Run-Time Performance Measures in Web Applications

This paper addresses the positive dynamic effects of the aspect-oriented implementation of database connection pooling in a Web application, through simulated experiments. In addition to the static positive effects of aspect-oriented programming (AOP) in yielding a robust design by ensuring encapsulation, reusability, efficiency, and extensibility, the dynamic positive effects of AOP in our experiments are emphasized and demonstrated elaborately in terms of some selected run-time performance measures. The latter issue is the main concern of our ongoing research work