Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

Publications by CRACS

2009

TOWARDS AN IMMUNE-INSPIRED TEMPORAL ANOMALY DETECTION ALGORITHM BASED ON TUNABLE ACTIVATION THRESHOLDS

Authors
Antunes, M; Correia, M; Carneiro, J;

Publication
BIOSIGNALS 2009: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON BIO-INSPIRED SYSTEMS AND SIGNAL PROCESSING

Abstract
The detection of anomalies in computer environments, like network intrusion detection, computer virus or spam classification, is usually based on some form of pattern search on a database of "signatures " for known anomalies. Although very successful and widely deployed, these approaches are only able to cope with anomalous events that have already been seen. To cope with these weaknesses, the "behaviour" based systems has been deployed. Although conceptually more appealing, they have still an impractical high rate of false alarms. The vertebrate Immune System is an emergent and appealing metaphor for new ideas on anomaly detection, being already adopted some algorithms and theoretical theories in particular fields, such as network intrusion detection. In this paper we present a temporal anomaly detection architecture based on the Grossman's Tunable Activation Threshold (TAT) hypothesis. The basic idea is that the repertoire of immune cells is constantly tuned according to the cells temporal interactions with the environment and yet retains responsiveness to an open-ended set of abnormal events. We describe some preliminary work on the development of an anomaly detection algorithm derived from TAT and present the results obtained thus far using some synthetic data-sets.

2009

Applying reinforcement learning to scheduling strategies in an actual grid environment

Authors
Costa, BF; Mattoso, M; Dutra, I;

Publication
International Journal of High Performance Systems Architecture

Abstract
Grid environments are dynamic and heterogeneous by nature, therefore requiring adaptive scheduling strategies. Reinforcement learning is an interesting and simple adaptive approach that may work well in actual grid environments. In this work, we employ reinforcement learning to classify available resources in a grid environment, giving support to two scheduling algorithms, AG and MQD. We study the makespan optimisation and load balancing. An algorithm known as RR is used for normalising purposes. Copyright © 2009 Inderscience Enterprises Ltd.

2009

UbiDis: a Flexible and General top-level Middleware to Manage Applications in Grids and Clusters

Authors
Fonseca, NA; Dutra, I;

Publication
IBERGRID: 3RD IBERIAN GRID INFRASTRUCTURE CONFERENCE PROCEEDINGS

Abstract
From an application point of view, the Grid computing with its powerful processing power and large amounts of data storage offers the possibility to process large quantities of data, to run computationally-intensive operations, or both. For instance, in computational biological pipelines, one often has to process large quantities of data in individually computationally-intensive operations. To process this data in the Grid, hundreds, or even thousands of jobs need to be submitted and their results processed. Obviously, performing these tasks manually is unfeasible. On the other hand, developing software to this end, specifically for a single application, is unproductive because if the application changes, or the Grid submission engine changes, then the code needs to be rewritten. In this paper we present a middleware that facilitates the submission of jobs to grids (or clusters) and helps handling their results. The middleware, that we call UbiDis (Ubiquitous Distribution), copies all files necessary for running the program to the UI or front-end host (in a Grid or cluster), compiles programs on the UI or front-end (if necessary), generates and submits the jobs, and copies the outputs to the local machine. Furthermore, UbiDis transparently generates jobs to different job managers, allowing the user to easily and quickly change the location to where the jobs are submitted. Finally, we illustrate the usefulness of UbiDis using two applications.

2009

Towards Patient Empowerment - Can the Patient Really Decide?

Authors
Falcao Reis, F; Correia, ME; Sousa, L;

Publication
WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING, VOL 25, PT 12

Abstract
Throughout the modern world, healthcare is in a crisis. In response, health information systems are going through major changes: focusing more on the patient and what the patient can do to help to improve his own health care. A lot has been said about what the patient's role should be in the 21(st) century. However, in a way, the patient is still being left out, without the ability to decide about his role and impotent to exercise his rights as the owner of his own EHR. Moreover, there exists a general lack of awareness among the general public about the major risks involved in the unbounded disclosure of personal health related data. The continuous growth of privacy incidents, resulting from target profiling and mining off individual health histories, by human resource departments or insurance companies, demonstrates the fragile perception the general public has for these matters. To help us in assessing this situation we have conducted several interviews with patients older than 18 years in order to determine their opinion on matters regarding 'patient empowerment' and their associated EHRs: particularly who should have access and what were the real reasons behind those answers. In this paper we analyze the results of our questionnaire and present and discuss in detail the answers provided by 100 patients: 70 female and 30 male from diverse strata of the Portuguese population.

2009

Telephone Interface for the Email Service

Authors
Baptista, N; Prior, R; Correia, ME;

Publication
2009 COMPUTATION WORLD: FUTURE COMPUTING, SERVICE COMPUTATION, COGNITIVE, ADAPTIVE, CONTENT, PATTERNS

Abstract
Several studies have demonstrated the advantages of using IVR (Interactive Voice Response) technologies[5], which allow the users to phone a computer and access services by pressing the appropriate touch-tone keys on their telephones. Because it offers substantial benefits in terms of cost and time efficiency, there is a continuous pursuit for increased automation using IVR. The real challenge lies in providing a user-friendly, yet cost-effective interface to users in order to improve their interaction with existing services, making them more usable and useful, providing an experience that fits their specific objectives and utilization contexts. This paper describes a method and system for providing customizable audio access to email messages kept in several IMAP (Internet Message Access Protocol) backstorages using an IVR application that takes full advantage of TTS (Text-To-Speech) software.

2009

ON THE STRENGTHENING OF OPENID AUTHENTICATION MECANISMS WITH THE PORTUGUESE CITIZEN CARD

Authors
Falcao Reis, F; Almeida, D; Correia, ME;

Publication
SISTEMAS E TECHNOLOGIAS DE INFORMACAO: ACTAS DA 4A CONFERENCIA IBERICA DE SISTEMAS E TECNOLOGIAS DE LA INFORMACAO

Abstract
With the massive migration of real world bureaucratic and business processes to the virtual world comes an ever increasing dependency on the security of the Internet infrastructure. To ensure the secure exchange of sensitive personal information and to help support the provisioning of a multitude of identity mechanisms and protocols there is an increased need for a very flexible, interoperable and user-centric Identity Management infrastructure. OpenID is a decentralized system protocol for user-centric identification and digital identity management in the Internet that is being largely deployed all over the world. In this paper we present Extended OpenID (EOID), an Identity Provider which leverages a secured OpenID 2.0 infrastructure with the recently released Portuguese Citizen Card (CC). EOID is composed by an OpenID server that uses the CC for strong authentication and a Firefox Plugin for an easier much more secure user experience.

  • 155
  • 192