José Bringel Filho

PhotoMap - automatic spatiotemporal annotation for mobile photos

The amount of photos in personal digital collections has grown rapidly making their management and retrieval a complicated task. In addition, existing tools performing manual spatial and content annotation are still time consuming for the users. To annotate automatically these photos using mobile devices is the emerging solution to decrease the lack of the description in photo files. In this context, this paper proposes a mobile and location-based system, called PhotoMap, for the automatic annotation and the spatiotemporal visualization of photo collections. PhotoMap uses the new technologies of the Semantic Web in order to infer information about the taken photos and to improve both the visualization and the retrieval. We also present a demonstration of the PhotoMap application during a tourist tour in the city of Grenoble.

PhotoMap: from location and time to context-aware photo annotations

Despite the growth of geotagged multimedia data on the Web, spatial and temporal metadata are still poorly exploited by Web search engines and multimedia systems. Interpretation and inference processes can enlarge these metadata towards high quality information that are useful for annotating multimedia automatically. In this article, we propose a semi-automatic approach for annotating personal photos based on the use of OWL-DL ontologies together with the next generation of mobile devices. We present an ontology called ContextPhoto and a contextual photo annotation approach which improve the development of more efficient personal image management tools. ContextPhoto provides concepts for representing captured and inferred context information reusing Web standards that describe spatial, temporal and social networking data. In order to validate the context annotation process we propose, we have also designed and developed a mobile and Web location-based system. This new system, called PhotoMap, is an evolution of the related mobile annotation systems since it provides automatic annotation about the spatial, temporal and social contexts of a photo. We also present a demonstration of the PhotoMap application during a tourist tour in the city of Rome.

A generalized context-based access control model for pervasive environments

Pervasive Computing Environments enable new opportunities for users to share and to access resources anytime and anywhere in a more natural way, making access control a critical issue. These heterogeneous and dynamic sensor-rich environments characterized by frequent and unpredictable changes on users, resources, and environment situations, call for access control solutions that allow dynamically adjust access permissions based on information describing the conditions of these entities (context), such as location and time. Some research attempts have been done based on existing models, which context information is used as an optional attribute for limiting the scope of access control permissions. However, these approaches normally exploit identities and roles dynamically assigned to the users in order to grant access permissions, which is an inappropriate solution for open and dynamic environments which we cannot assume the existence of predefined roles and user-role associations. In this scenario, we claim that access permissions should be assigned to the users only based on context information characterizing the three most important entities of any access control framework: owners, requestors, and resources. Thus, this paper proposes a generalized context-based access control model for making access control decisions completely based on context information.

A semantic approach and a web tool for contextual annotation of photos using camera phones

The increasing number of personal digital photos on the Web makes their management, retrieval and visualization a difficult task. To annotate these images using Semantic Web technologies is the emerging solution to decrease the lack of the description in photos files. However, existing tools performing manual annotation are time consuming for the users. In this context, this paper proposes a semi-automatic approach for annotating photos and photo collections combining OWL-DL ontologies and contextual metadata acquired by mobile devices. We also describe a mobile and Web-based system, called PhotoMap, that provides automatic annotation about the spatial, temporal and social contexts of a photo (i.e., where, when, and who). PhotoMap uses the Web Services and Semantic Web reasoning methods in order to infer information about the taken photos and to improve both browsing and retrieval.

Using Context Quality Indicators for Improving Context-Based Access Control in Pervasive Environments

In pervasive computing environments (PCE), context information can have a strong impact on application adaptation, not only at application logic level but also security management level. From a access control perspective, it is required that the access control models take into account context information such as location and time, in determining whether access should be allowed or not. As context information represents real-world situations, it is associated with certain quality indicators that can influence directly in the access control decisions. In this paper, we showed the use of context information and its quality indicators to grant and to adapt access permissions to resources in the PCE.

A Quality-Aware Context-Based Access Control model for ubiquitous applications

With the growing advancement of ubiquitous computing (UbiComp), we are moving towards an era where access control and security policies will be based on context information. As context information represents real-world situations, it is associated with certain quality indicators that can directly influence the access control decisions. In this paper, we propose a quality-aware context-based access control model that takes into account the context information and its QoC indicators to grant and to adapt access permissions to resources.

Annotation-Based Access Control Approach for Ubiquitous Systems

With the growing production and access of resources managed by sensor-rich ubiquitous devices, such as photos, videos, and services, critical issues arise from access control point of view. Sensor-rich devices offer users new opportunities for creating, accessing, and sharing resources from anywhere and at anytime, interacting dynamically with other surrounding devices, users, and the environment. In this scenario, resources could be automatically annotated with information characterizing situations (context) to facilitate retrieval, organization, and enrichment of their contents. Moreover, resources may be available by users only on a specific situation (e.g., location and season), such as surveys asking visitors about touristic attractions while visiting them. However, existing ubiquitous applications do not exploit contextual and social annotation as central concept for defining access control policies to protect resources. Therefore, this paper proposes a context-aware rule-based access control model for protecting ubiquitous resources, presenting a prototype that implements this model, a case study based on an ubiquitous survey application, as well as performance evaluation results that demonstrate the effectiveness and scalability of the proposed solution.

Une architecture sensible au contexte pour le développement des systèmes d'administration pour l'enseignement

The increasing use of mobile devices and wireless communication technologies has improved the access to web information systems. However, the development of these systems imposes new challenges mainly due to the heterogeneity of mobile devices, the management of context information, and the complexity of adaptation process. Especially in this case, these systems should be runable on a great number of mobile devices models. In this article, we describe a context-aware architecture that provides solutions to the challenges presented above for the development of education administration systems.