In the modern age everyone needs access to Internet; Visually handicapped are not an exception for that. SPECS (SPEcialized Computer System) is a system developed to give access to the visually handicapped. It has a Braille shell. The user can enter his spoken language. After the selection of the language the user can present his request to the browser through chosen language in Braille. The ou...

Despite its widespread usage, the Unified Modeling Language (UML) specification still lacks formal, explicit, support for access control. This paper proposes an approach to model security as a separate concern by augmenting UML with separate and new diagrams for role-based, discretionary, and mandatory access controls; collectively, these diagrams provide visual access-control aspects. Individu...

People’s work days are filled with exceptions to normal routine. These exceptions affect the security and privacy of their information access and sharing. In a recent ethnographic study of ten users in the Bay Area, we identify a number of key problems not well addressed by current data sharing technologies, and from them derive requirements for Ad-hoc Guesting, our term for minimal, readily av...

Wireless communications are becoming an important part of our everyday lifestyle. One major area that will have an enormous impact on the performance of wireless ad hoc networks is the medium access control (MAC) layer. Current random access MAC protocols for ad hoc networks support reliable unicast but not reliable broadcast. In this paper, we proposed a random access MAC protocol, Broadcast S...

We present an approach to an aspect of managing complex access scenarios to large and heterogeneous corpora that involves handling user queries that, intentionally or due to the complexity of the queried resource, target texts or annotations outside of the given user’s permissions. We first outline the overall architecture of the corpus analysis platform KorAP, devoting some attention to the wa...

We propose a modelling language and verification tool, called X -Policy, for web-based collaborative systems with dynamic access control policies. The access to resources in these systems depends on the state of the system and its configuration. The X -Policy language expresses systems as a set of programs. Those programs can model system operations which are executed by users. The X -Policy la...