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Publicações

2012

Automatic Localization of the Optic Disc in Retinal Images Based on the Entropy of Vascular Directions

Autores
Mendonca, AM; Cardoso, F; Sousa, AV; Campilho, A;

Publicação
IMAGE ANALYSIS AND RECOGNITION, PT II

Abstract
This paper proposes an automatic method for estimating the location of the optic disc in color images of the retina. The proposed methodology is founded in a new concept, the entropy of vascular directions, which proved to be a reliable measure for assessing the convergence of vessels around an image point. To improve the robustness of the method, the search for the maximum value of entropy is restricted to image areas with high intensity. This new method was evaluated in two publicly available databases, containing both normal and pathological images, and was able to obtain a valid location for the optic disc in 115 out of the 121 images of the two datasets.

2012

Blind navigation support system based on Microsoft Kinect

Autores
Filipe, V; Fernandes, F; Fernandes, H; Sousa, A; Paredes, H; Barroso, J;

Publicação
PROCEEDINGS OF THE 4TH INTERNATIONAL CONFERENCE ON SOFTWARE DEVELOPMENT FOR ENHANCING ACCESSIBILITY AND FIGHTING INFO-EXCLUSION (DSAI 2012)

Abstract
This paper presents a system which extends the use of the traditional white cane by the blind for navigation purposes in indoor environments. Depth data of the scene in front of the user is acquired using the Microsoft Kinect sensor which is then mapped into a pattern representation. Using neural networks, the proposed system uses this information to extract relevant features from the scene, enabling the detection of possible obstacles along the way. The results show that the neural network is able to correctly classify the type of pattern presented as input.

2012

Iberia 2.0 A Way To Leverage Web 2.0 In Organizations

Autores
Martins, J; Goncalves, R; Pereira, J; Cota, M;

Publicação
INFORMATION SYSTEMS AND TECHNOLOGIES

Abstract
The Internet and specially the Web 2.0, when combined with the organizations business processes and used in their e-business initiatives, may bring an enormous set of competitive advantages. Despite the slow pass at which the organizations are incorporating Web 2.0 in their business initiatives, these actions are still being made without following any methodology or set of guidelines, thus resulting in inconstant return of investment. With this in mind, we present a project that, by analyzing and studying several case studies, aims on achieving a methodology or a set of guidelines that allow organizations to better plan and execute their Web 2.0 business initiatives.

2012

Extension and Implementation of ClassSheet Models

Autores
Cunha, J; Fernandes, JP; Mendes, J; Saraiva, J;

Publicação
2012 IEEE SYMPOSIUM ON VISUAL LANGUAGES AND HUMAN-CENTRIC COMPUTING (VL/HCC)

Abstract
In this paper we explore the use of models in the context of spreadsheet engineering. We review a successful spreadsheet modeling language, whose semantics we further extend. With this extension we bring spreadsheet models closer to the business models of spreadsheets themselves. An addon for a widely used spreadsheet system, providing bidirectional model-driven spreadsheet development,

2012

Factors influencing hospital high length of stay outliers

Autores
Freitas, A; Silva Costa, T; Lopes, F; Garcia Lema, I; Teixeira Pinto, A; Brazdil, P; Costa Pereira, A;

Publicação
BMC HEALTH SERVICES RESEARCH

Abstract
Background: The study of length of stay (LOS) outliers is important for the management and financing of hospitals. Our aim was to study variables associated with high LOS outliers and their evolution over time. Methods: We used hospital administrative data from inpatient episodes in public acute care hospitals in the Portuguese National Health Service (NHS), with discharges between years 2000 and 2009, together with some hospital characteristics. The dependent variable, LOS outliers, was calculated for each diagnosis related group (DRG) using a trim point defined for each year by the geometric mean plus two standard deviations. Hospitals were classified on the basis of administrative, economic and teaching characteristics. We also studied the influence of comorbidities and readmissions. Logistic regression models, including a multivariable logistic regression, were used in the analysis. All the logistic regressions were fitted using generalized estimating equations (GEE). Results: In near nine million inpatient episodes analysed we found a proportion of 3.9% high LOS outliers, accounting for 19.2% of total inpatient days. The number of hospital patient discharges increased between years 2000 and 2005 and slightly decreased after that. The proportion of outliers ranged between the lowest value of 3.6% (in years 2001 and 2002) and the highest value of 4.3% in 2009. Teaching hospitals with over 1,000 beds have significantly more outliers than other hospitals, even after adjustment to readmissions and several patient characteristics. Conclusions: In the last years both average LOS and high LOS outliers are increasing in Portuguese NHS hospitals. As high LOS outliers represent an important proportion in the total inpatient days, this should be seen as an important alert for the management of hospitals and for national health policies. As expected, age, type of admission, and hospital type were significantly associated with high LOS outliers. The proportion of high outliers does not seem to be related to their financial coverage; they should be studied in order to highlight areas for further investigation. The increasing complexity of both hospitals and patients may be the single most important determinant of high LOS outliers and must therefore be taken into account by health managers when considering hospital costs.

2012

Next challenges for adaptive learning systems

Autores
Zliobaite, I; Bifet, A; Gaber, MM; Gabrys, B; Gama, J; Minku, LL; Musial, K;

Publicação
SIGKDD Explorations

Abstract

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