Nikoletta Mavrogeorgi

Content Based SLAs in Cloud Computing Environments

In this paper, we address the problem of managing SLAs in cloud computing environments. The idea is to take advantage of the content terms that concern the objects and support more efficient capabilities, such as quicker search and retrieval of the objects. As a result, the operational cost is reduced and consequently this fact lessens the customers charge.

A Monitoring Mechanism for Storage Clouds

Managing a Cloud is a difficult task that calls for the deployment and co-operation of many different decision making mechanisms. What all of them have in common is that they need accurate monitoring information to effectively make decisions. Therefore, the deployment of a reliable monitoring mechanism is of paramount importance in the Cloud ecosystem. Guaranteeing Quality of Service coupled with the large scale and distributed nature of Clouds further amplify the need for an effective and light-weight monitoring solution. In this paper we present the architectural design and implementation of the monitoring solution designed within the context of the VISION Cloud project. Our aim is to provide a scalable solution that is able to meet the needs of a large scale Storage Cloud.

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.

Use of Ontologies for Knowledge Representation of a Film Scene

In the present paper we explore ontologies, as a means to capture knowledge of the film-making domain. More specifically, we intend to open a discussion so as to guide the development of DirectorNotation, an under-development open-source tool for representing media content, as of its pre-production and production phases, using a symbolic notation system, in which a film director can formally record his intentions. DirectorNotations authors suggest ontologies for formalizing and reasoning over their notation system. The current paper discusses this technical choice, considering its limitations, and makes suggestions about the work that needs to be performed if these limitations are to be overcome.

Customized SLAs in Cloud Environments

Nowadays, the demand for online storage is increasing. Customers store their data and can retrieve them anytime and from anywhere without having to care about back up and data recovery. SLAs between Cloud providers and customers determine the level of service guaranteed by the former. A customer can be anyone from an individual person to enterprises. Customers have different needs and preferences. Our proposed system permits the creation and enforcement of customized SLAs, where customers choose the requirements that they need fulfilled. The proposed SLAs are associated with content terms pertaining to the nature of the content of the data stored. SLA enforcement is based on rules that are updated in runtime in order to proactively detect possible SLA violations and handle them in an appropriate manner.

A Holistic View of Information Management in Cloud Environments

The emergence of Cloud technologies ultimately affected the service computing ecosystem introducing new roles and relationships as well as new architectural and business models. Along with the increase of the capabilities and potentials of the service providers came the increase of the information being available and the need to manage it in an efficient way. To this end, in this paper we present a management service architecture as well as the information model that the solution is based on. The model has been designed to serve a storage service provided by a Cloud infrastructure but the approach is implemented in a flexible and modular fashion in order to support different Cloud situations.

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.

Robust Content-Centric SLA Enforcement in Federated Cloud Environments

In this paper we present a system for declaring and enforcing SLAs in Cloud environments. The SLAs proposed are enriched with content terms, storlets and federation capabilities and provide high degrees of customizability for clients. A mechanism for SLA enforcement has been designed and implemented which, based on policies, measurements, usage data computations, and monitoring methods permits proactive SLA violation detection and handling. SLA renegotiation is supported as well. The proposed framework has been developed and evaluated in challenging scenarios in a variety of different application domains.

Dynamic Rule Based SLA Management in Clouds

Currently there is significant and increasing demand for quick data storage and access any time. Storage is a fundamental need and Cloud environments accomplish this. The evolvement of the IT technologies offers the user to a large variety of useful services. In order for the user to have a guarantee for these services SLAs are signed. In this paper, we present an SLA Management mechanism for Cloud environments. SLA enforcement is based on rules that are updated in runtime in order to proactively detect possible SLA violations and handle them in an appropriate manner.

Mobile Terminal Subarea Localisation Method in GSM Networks

In this paper, a novel method for mobile terminal (MT) subarea localisation in GSM networks is presented. No base stations position and additional hardware are required. It is a variation of the fingerprinting localisation method aiming to determine not the MT geographic position but the MT subarea and to reduce necessary initialisation measurements. Several GSM-based methods have been developed for MT localisation. The localisation method, proposed in this paper, is based on the fingerprinting method but is differentiated regarding the produced result. In this method the location server does not compare the MT collected radio network measurements with the stored radio map but with the subareas proprietary characteristics indicating the subarea where the MT is located and not the exact MT geographic position. Finally, if an LBS requires as input the subscriber subarea and not the geographic position then the novel method presented here reduces significantly the localisation initialisation requirements and computational cost in order to provide the service.