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

2011

A Real time, Wearable ECG and Continous Blood Pressure Monitoring System for First Responders

Authors
Ribeiro, DMD; Colunas, MFM; Ferreira Marques, FAF; Fernandes, JM; Silva Cunha, JPS;

Publication
2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)

Abstract
The study of stress and fatigue among First Responders is a major step in mitigating this public health problem. Blood pressure, heart rate variability and fatigue related arrhythmia are three of the main "windows" to study stress and fatigue. In this paper we present a wearable medical device, capable of acquiring an electrocardiogram and estimating blood pressure in real time, through a pulse wave transit time approach. The system is based on an existent certified wearable medical device called "Vital Jacket" and is aimed to become a tool to allow cardiologists in studying stress and fatigue among first response professionals.

2011

Learning decision rules from data streams

Authors
Gama, J; Kosina, P;

Publication
IJCAI International Joint Conference on Artificial Intelligence

Abstract
Decision rules, which can provide good interpretability and flexibility for data mining tasks, have received very little attention in the stream mining community so far. In this work we introduce a new algorithm to learn rule sets, designed for open-ended data streams. The proposed algorithm is able to continuously learn compact ordered and unordered rule sets. The experimental evaluation shows competitive results in comparison with VFDT and C4.5rules.

2011

Modal Interferometric Sensor Based in a Birefringent Boron-doped Microstructured Fiber

Authors
Statkiewicz Barabach, G; Carvalho, JP; Frazao, O; Olszewski, J; Mergo, P; Santos, JL; Urbanczyk, W;

Publication
INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
Microstructured optical fibers (MOFs) have been widely studied owing to their potential for obtaining novel transmission, nonlinear and sensing characteristics. Sensing applications of MOFs cover various types of devices for measurements of different physical and specific chemical compounds in gases and liquids employing evanescent field techniques. Such fibers can also be used as active and passive elements in fiber-optic polarimetric and interferometric sensors. We present an in-line fiber modal interferometer fabricated in boron-doped highly birefringent microstructured fiber. The boron-doped region located in the middle of the core decreases the effective index of the fundamental mode and facilitates coupling between the fundamental and the first order mode. The coupling regions have the form of fiber narrowings fabricated using CO2 laser and are distant by a few millimeters. The spectral intensity at the sensor output is modulated only by intermodal interference produced by a short piece of fiber between the two coupling points. Moreover, as the fiber is highly birefringence, each pair of polarization modes produces its own intermodal fringes, which results in the contrast modulation of the overall interference signal observed at the fiber output, and provides an additional degree of freedom to measure simultaneously a pair of measurands.

2011

Optimal offering strategies to the day-ahead market by a wind power producer

Authors
Pousinho, HMI; Mendes, VMF; Catalao, JPS;

Publication
IET Conference Publications

Abstract
This paper develops a computational tool, based on two-stage stochastic programming, for a wind power producer bidding in the electricity market. The uncertainty related to electricity market prices and wind power production is taken into account. A hybrid intelligent technique, combining wavelet transform, particle swarm optimization and adaptive-networkbased fuzzy inference system, enables the generation of scenarios. Besides, risk aversion is considered using the conditional value-at-risk methodology. Computer simulation results are provided and analyzed. Finally, conclusions are duly drawn.

2011

A framework to develop meta web interfaces

Authors
Leal, JP; Dias, H;

Publication
Proceedings of the IADIS International Conference WWW/Internet 2011, ICWI 2011

Abstract
Web interfaces are used nowadays for virtually every kind of computer application. The proliferation of web interfaces created the need to collect and analyze data on how users interact with them. Many web applications used for this purpose rely on what can be called a meta web interface. Meta web interfaces are used for different purposes but they share a set of common features: a web interface based on the subject interface with a second layer interface for collecting data, a central repository for persisting the collected data, and an API for retrieving aggregated data on user interaction. This paper describes Z-Web - a framework for developing meta web interfaces that provides these three features. To create a second layer in the meta web interface a Z-Web server is placed as a proxy between the web client and the subject web server and injects modifications while forwarding HTTP requests. These modifications are typically JavaScript libraries that collect and store data related to user interaction. The framework caches the pages it proxies and provides persistent storage for the collected data. An application interface (API) makes this data available to client application supported by Z-Web. This paper presents an overview of Z-Web, with the general architecture of a web application based on this framework, and describes the design and implementation issues of its main components. Two systems developed with Z-Web are also presented to evaluate the applicability of the framework and its overhead when compared with similar systems.

2011

Rigorous Software Development - An Introduction to Program Verification

Authors
Almeida, JB; Frade, MJ; Pinto, JS; Sousa, SMd;

Publication
Undergraduate Topics in Computer Science

Abstract

  • 3376
  • 4362