Angelos Yannopoulos

A secure framework exploiting content guided and automated algorithms for real time video searching

This paper presents an architecture that allows End Users, via the services of Search Engines, to search, in a secure and efficient way, the video content belonging to Content Providers. The search can be accomplished with any searching scheme that the Search Engines wish to provide, as long as certain security constraints are met. However we propose specific algorithms that demonstrate an efficient way to search video data without sacrificing security effectiveness of the system. The search is completed without the End Users or Search Engines needing to purchase the premium content beforehand, and without the Content Providers needing to purchase the search technology. The business motivation of this technique is to assist End Users to purchase content best suiting their requirements--they are offered search results only, not actual content. The objective is to face the problem caused by the current segregation between content ownership and video processing technology ownership. To face this segregation, we present an architecture that guarantees security of Content Providers data and Search Engines technology and we also present two innovative algorithms that make real time video searching a feasible process. Particularly these algorithms (a) organize video content into a graph based hierarchical structure and (b) perform content guided, non interactive and real time search by exploiting the graph based video structures. The proposed algorithms are incorporated in the presented architecture under the given security constraints. Experimental results and comparisons with conventional techniques are presented to demonstrate the outperformance of the proposed algorithms.

Cultural Heritage Experience with Virtual Reality According to User Preferences

—In this paper, we present the VREditor, an easy-to-use authoring tool for annotating a scene with augmented reality features (images, videos, animations, sounds, and texts). The output of this editor is the creation of an augmented reality world. The user lives in this generated virtual world and he can choose according to his preferences (for instance, artistic, political, cultural, military data, etc.), which augmented reality features he desires to be presented to him, having as a result to live an immersive experience virtually.

A social-aware multimedia system for interactive cultural and educational experiences

The paper shows how different concepts and technologies, such as high quality multimedia content production and delivery, social media interaction, and methodologies for monitoring and analysing social network activity, can be practically combined with traditional virtual reality installations into an innovative experimental system that enhances the experience of the visitors in cultural educational centers. Apart from offering a modern, immersive, richer experience to the visitors, the proposed system involves significant benefits for the organizers as well, supplying them with valuable feedback extracted from the monitoring and analysis mechanisms. The experimental system has been successfully deployed and used in the Foundation of the Hellenic World cultural center.

Moving e-commerce with PIVOTS: private information viewing offering total safety

We present a technology which enables wide-scale deployment of a unique and powerful data access and search tool. This tool makes it possible for content owners on the Internet to offer end-users the ability to search, assess, or otherwise examine their nondisclosable private data. The end-users may use arbitrary, distrusted assessment algorithms and receive the results which are produced. These results take the form of a meaningful digest, e.g., a useful statistic, a relevance assessment, etc. There exists some controllable danger of information theft which, however, is quantitatively dependent on system parameters and can be tuned accordingly. We consider a broad class of practical applications where brute force attacks exist which are easier and cheaper to implement than an attack through appropriately configured PIVOTS, making our system, effectively, very trustworthy. The actual creation of the search algorithm may be performed by the end-users themselves in specialized applications, or by third-party search-engine operators who offer their services to end-users. Sophisticated data mining technologies which are very often not directly available to content owners can thus be exploited to mine even private data collections. Users discovering interesting items in private data sets may purchase this specific data, but other desirable exploitation possibilities are also analyzed. A novel business model is presented and its potential for great impact on e-commerce is explored. Three diverse and important real-world applications are presented in conclusion.

Metadata, Domain Specific Languages and Visualisations as Internal Artifacts Driving an Agile Knowledge Engineering Methodology

We introduce M(krDSL), an agile Knowledge Engineering methodology. It addresses the Knowledge Acquisition bottleneck. The point of differentiation of M(krDSL) from previous practice involves knowledge engineers and domain experts collaborating extremely closely: “The domain expert constructs the model. The model is independently useful as a communication tool.” We introduce two additional layers of abstraction between human domain experts and operational software: a shared Knowledge Model of the domain, and Visualisation mockups/prototypes. Tools of the methodology include: DSLs and graphical representations; Qualitative analysis of the DSLs; Semantic Metadata for Test Driven Design; and analysis of concurrently evolving Visualisation output mockups/prototypes. In our experience, following this methodology helped us escape from situations where we had completely ceased to be able to make any modelling progress at all, while even at times when we were able to make easy progress in our KE tasks, M(krDSL) gave us a high degree of confidence in the correct prioritisation and correct results of our work.

Vivid Educational Experience with Virtual Reality

In this paper, we present an educational system that represents cultural heritage virtually. The system contains an editor for specifying the educational scripts which will be displayed at Augmented Reality and Mixed Reality. The editor is a very simple application interface for Augmented Reality and Mixed Reality developers. It is a useful and easy-to-use tool for editing educational scripts for augmented reality and for exporting X3D files from the developer’s input. The X3D files permit the generation of the augmented reality world. Augmented and Mixed reality permit real and virtual world to be combined. This interaction is done in real-time. The editor enables developers to facilitate their work,that is creating educational scripts of augmented reality. A web service requests a) the localization of the user that is found by the device (PDA) which the user utilizes and b) the user preferences that desires to get informed (political data, cultural data etc). After these data are specified, the web service provides information and scenarios to the user according to his preferences and to the sight where the user is located (found according to his location). The user can interact with these scenarios, living historical immersive experiences virtually.