Search results for " access"

Mobile Encounter Networks and Their Applications

2008

This article presents mobile encounter networks (MENs), which emerge when mobile devices come across each other and form a temporary connection between them using a common short-range radio technology. Local information exchanges between mobile devices results in a broadcast diffusion of information to other users of the network with a delay. Gasoline price comparison system (GPCS), which delivers newest gasoline prices to mobile users using mobile encounter information diffusion, is described as well as other application areas where MENs could be used. The feasibility of building MENs using bluetooth is tested with the BlueCheese mobile encounter network middleware and it is found that the…

Complete Shadowing Modeling and its Effect on System Level Performance Evaluation

2008

Computer simulations are a common procedure for assessing the performance of new algorithms. To conduct a valid and accurate study, the models employed in such simulators need to be carefully selected. Regarding shadowing modeling, one-dimensional models are fairly commonplace in the literature. While simple and with low computational costs, these models can not produce correlated fading values for mobiles that are in nearby positions and, besides, do not include the cross-correlation effect. To overcome these limitations, this paper presents a bi-dimensional shadowing model which introduces both the spatial correlation and the cross-correlation present in real systems. Finally, the impact …

Multicast TV over WLAN in a University Campus Network

2009

One of the multimedia services offered by the campus network of the Polytechnic University of Valencia is TV over IP. This service works well in the devices connected directly to the wired network but we have detected some problems when the receivers access to the campus network through wireless IEEE 802.11, especially when devices roam across the Campus. In this paper we propose and evaluate a server-based solution to minimize the packet loss and reduce the lack of service when the mobile devices roam from an Access Point to another Access Point in the wireless network. This solution uses a location system to modify the behaviour of standard multicasting protocols in order to get a near-se…

Technology for supporting web information search and learning in Sign Language

2009

Sign Languages (SL) are underrepresented in the digital world, which contributes to the digital divide for the Deaf Community. In this paper, our goal is twofold: (1) to review the implications of current SL generation technologies for two key user web tasks, information search and learning and (2) to propose a taxonomy of the technical and functional dimensions for categorizing those technologies. The review reveals that although contents can currently be portrayed in SL by means of videos of human signers or avatars, the debate about how bilingual (text and SL) versus SL-only websites affect signers' comprehension of hypertext content emerges as an unresolved issue in need of further empi…

Accessible On-Line Floor Plans

2015

Better access to on-line information graphics is a pressing need for people who are blind or have severe vision impairment. We present a new model for accessible presentation of on-line information graphics and demonstrate its use for presenting floor plans. While floor plans are increasingly provided on-line, people who are blind are at best provided with only a high-level textual description. This makes it difficult for them to understand the spatial arrangement of the objects on the floor plan. Our new approach provides users with significantly better access to such plans. The users can automatically generate an accessible version of a floor plan from an on-line floor plan image quickly …

Information structure and practice as facilitators of deaf users' navigation in textual websites

2009

Deaf users might find it difficult to navigate through websites with textual content which, for many of them, constitutes the written representation of a non-native oral language. With the aim of testing how the information structure could compensate for this difficulty, 27 prelingual deaf users of sign language were asked to search a set of headlines in a web newspaper where information structure and practice were manipulated. While practice did not affect deep structures (web content distributed through four layers of nodes), wide structures (web content concentrated in two layers) did facilitate users' performance in the last trial block and compromised it in the first trial block. It is…

LifeRescue Software Prototype for Supporting Emergency Responders During Fire Emergency Response: A Usability and User Requirements Evaluation

2017

For an efficient emergency response, emergency responders (ERs) should exchange information with one another to obtain an adequate understanding and common operational picture of the emergency situation. Despite the current developments on information systems, many ERs are unable to get access to the relevant information as the data is heterogeneous and distributed at different places and due to security and privacy barriers. As a result, ERs are unable to coordinate well and to make good decisions. Therefore, to overcome these difficulties, a web-based application called LifeRescue was developed for supporting easy information access during emergency search and rescue operation. The goal o…

The temple of visual culture and people with visual impairments: museum accessibility as mental colonization

Accessibility raises political and cultural questions about inclusion and inclusive practices. Museums worldwide now offer multisensory access programs for people with visual impairments, which could appear as an actual implementation of the purpose of the Convention on the Rights of Persons with Disabilities of full inclusion and respect of disabled pleople as part of human diversity. However, by focusing on touch, they often passively exclude people with visual impairments because of their foundation in ocularcentric assumptions about knowledge, misconceptions about visual impairments, and aesthetic and epistemological potential of other 'senses'. Differently, approaches deeply aware of s…

Expectations, experiences and attitudes of patients and primary care health professionals regarding online psychotherapeutic interventions for depres…

2013

Abstract Background In the year 2020, depression will cause the second highest amount of disability worldwide. One quarter of the population will suffer from depression symptoms at some point in their lives. Mental health services in Western countries are overburdened. Therefore, cost-effective interventions that do not involve mental health services, such as online psychotherapy programs, have been proposed. These programs demonstrate satisfactory outcomes, but the completion rate for patients is low. Health professionals’ attitudes towards this type of psychotherapy are more negative than the attitudes of depressed patients themselves. The aim of this study is to describe the profile of d…

A MAS Security Framework Implementing Reputation Based Policies and Owners Access Control

2006

Multi-agent systems expose users to risks related to lack of knowledge above interacting users. Such systems should provide tools to protect their own resources from illegal accesses by unauthorized users. This paper describes a security framework for Multi-agent systems preventing a trusted agent to interact with malicious agents and granting agent and platform resources. This feature is obtained adding an access control mechanism that joins the benefits of Credential Based Access Control, Role Based Access Control and Mandatory Access Control. Authorizations and access control policies are set by XML based policy files. A case study on a distributed document retrieval system is also illus…