Biblio
Wikipedia is one of the most popular information platforms on the Internet. The user access pattern to Wikipedia pages depends on their relevance in the current worldwide social discourse. We use publically available statistics about the top-1000 most popular pages on each day to estimate the efficiency of caches for support of the platform. While the data volumes are moderate, the main goal of Wikipedia caches is to reduce access times for page views and edits. We study the impact of most popular pages on the achievable cache hit rate in comparison to Zipf request distributions and we include daily dynamics in popularity.
Semantic Web has brought forth the idea of computing with knowledge, hence, attributing the ability of thinking to machines. Knowledge Graphs represent a major advancement in the construction of the Web of Data where machines are context-aware when answering users' queries. The English Knowledge Graph was a milestone realized by Google in 2012. Even though it is a useful source of information for English users and applications, it does not offer much for the Arabic users and applications. In this paper, we investigated the different challenges and opportunities prone to the life-cycle of the construction of the Arabic Knowledge Graph (AKG) while following some best practices and techniques. Additionally, this work suggests some potential solutions to these challenges. The proprietary factor of data creates a major problem in the way of harvesting this latter. Moreover, when the Arabic data is openly available, it is generally in an unstructured form which requires further processing. The complexity of the Arabic language itself creates a further problem for any automatic or semi-automatic extraction processes. Therefore, the usage of NLP techniques is a feasible solution. Some preliminary results are presented later in this paper. The AKG has very promising outcomes for the Semantic Web in general and the Arabic community in particular. The goal of the Arabic Knowledge Graph is mainly the integration of the different isolated datasets available on the Web. Later, it can be used in both the academic (by providing a large dataset for many different research fields and enhance discovery) and commercial sectors (by improving search engines, providing metadata, interlinking businesses).
This paper presents a novel visual analytics technique developed to support exploratory search tasks for event data document collections. The technique supports discovery and exploration by clustering results and overlaying cluster summaries onto coordinated timeline and map views. Users can also explore and interact with search results by selecting clusters to filter and re-cluster the data with animation used to smooth the transition between views. The technique demonstrates a number of advantages over alternative methods for displaying and exploring geo-referenced search results and spatio-temporal data. Firstly, cluster summaries can be presented in a manner that makes them easy to read and scan. Listing representative events from each cluster also helps the process of discovery by preserving the diversity of results. Also, clicking on visual representations of geo-temporal clusters provides a quick and intuitive way to navigate across space and time simultaneously. This removes the need to overload users with the display of too many event labels at any one time. The technique was evaluated with a group of nineteen users and compared with an equivalent text based exploratory search engine.
Web Services can be invoked from anywhere through internet without having enough knowledge about the implementation details. In some cases, single service cannot accomplish user needs. One or more services must be composed which together satisfy the user needs. Therefore, security is the most important concern not only at single service level but also at composition level. Several attacks are possible on SOAP messages communicated among Web Services because of their standardized interfaces. Examples of Web Service attacks are oversize payload, SOAPAction spoofing, XML injection, WS-Addressing spoofing, etc. Most of the existing works provide solution to ensure basic security features of Web Services such as confidentiality, integrity, authentication, authorization, and non-repudiation. Very few of the existing works provide solutions such as schema validation and schema hardening for attacks on Web Services. But these solutions do not address and provide attack specific solutions for SOAP messages communicated between Web Service. Hence, it is proposed to provide solutions for two of the prevailing Web Service attacks. Since new types of Web Service attacks are evolving over time, the proposed security solutions are implemented as APIs that are pluggable in any server where the Web Service is deployed.
In this paper, we present an open cloud DRM service provider to protect the digital content's copyright. The proposed architecture enables the service providers to use an on-the fly DRM technique with digital signature and symmetric-key encryption. Unlike other similar works, our system does not keep the encrypted digital content but lets the content creators do so in their own cloud storage. Moreover, the key used for symmetric encryption are managed in an extremely secure way by means of the key fission engine and the key fusion engine. The ideas behind the two engines are taken from the works in secure network coding and secret sharing. Although the use of secret sharing and secure network coding for the storage of digital content is proposed in some other works, this paper is the first one employing those ideas only for key management while letting the content be stored in the owner's cloud storage. In addition, we implement an Android SDK for e-Book readers to be compatible with our proposed open cloud DRM service provider. The experimental results demonstrate that our proposal is feasible for the real e-Book market, especially for individual businesses.