Universidade de Pernambuco

About: Universidade de Pernambuco is a education organization based out in Recife, Brazil. It is known for research contribution in the topics: Population & Artificial neural network. The organization has 6147 authors who have published 6948 publications receiving 73648 citations.

Modeling Interference in Wireless Ad Hoc Networks

Abstract: We present interference analysis for wireless ad hoc networks and show that, depending on the path loss parameter (alpha), the average signal to noise and interference ratio (SNIR) either remains constant, or decays, when the number of interferers scales to infinity in the network, for nodes communicating with their close neighbors. Thus, communication is feasible in dense networks as long as alpha > 2 and a node attempts to transmit to other nodes located close enough so that interference can be overcome. An analytical model for interference is described and Monte-Carlo simulations validate our results.

Encryption of medical images based on the cosine number transform

Abstract: In this paper, we introduce a novel scheme for encryption of medical images. The technique is based on the cosine number transform, a mathematical tool whose application requires modular arithmetic only. This property avoids rounding-off errors and allows that the image recovered after the encryption/decryption process be identical to the corresponding original image. The proposed scheme is flexible and can be applied to images complying with the DICOM standard, which is frequently employed in medical applications. We show that the technique is capable of resisting the main cryptographic attacks.

High-intensity interval training versus moderate-intensity continuous training on exercise capacity and quality of life in patients with coronary artery disease: A systematic review and meta-analysis.

Abstract: BackgroundExercise is an effective strategy for reducing total and cardiovascular mortality in patients with coronary artery disease. However, it is not clear which modality is best. We performed a meta-analysis to investigate the effects of high-intensity interval versus moderate-intensity continuous training of coronary artery disease patients.MethodsWe searched MEDLINE, PEDro, LILACS, SciELO and the Cochrane Library (from the earliest date available to November 2016) for controlled trials that evaluated the effects of high-intensity interval versus moderate-intensity continuous training for coronary artery disease patients. Weighted mean differences and 95% confidence intervals were calculated, and heterogeneity was assessed using the I2 test.ResultsTwelve studies met the study criteria, including 609 patients. High-intensity interval training resulted in improvement in peak oxygen uptake weighted mean difference (1.3 ml/kg/min, 95% confidence interval: 0.6–1.9, n = 594) compared with moderate-intensit...