CONTEXT AND OBJECTIVE: Type 2 diabetes is a chronic disease associated with a wide range of serious health complications that have a major impact on overall health. The aims here were to develop and validate predictive models for detecting undiagnosed diabetes using data from the Longitudinal Study of Adult Health (ELSA-Brasil) and to compare the performance of different machine-learning algorithms in this task. DESIGN AND SETTING:Comparison of machine-learning algorithms to develop predictive models using data from ELSA-Brasil. METHODS: After selecting a subset of 27 candidate variables from the literature, models were built and validated in four sequential steps: (i) parameter tuning with tenfold cross-validation, repeated three times; (ii) automatic variable selection using forward selection, a wrapper strategy with four different machinelearning algorithms and tenfold cross-validation (repeated three times), to evaluate each subset of variables; (iii) error estimation of model parameters with tenfold cross-validation, repeated ten times; and (iv) generalization testing on an independent dataset. The models were created with the following machine-learning algorithms: logistic regression, artificial neural network, naïve Bayes, K-nearest neighbor and random forest. RESULTS:The best models were created using artificial neural networks and logistic regression. These achieved mean areas under the curve of, respectively, 75.24% and 74.98% in the error estimation step and 74.17% and 74.41% in the generalization testing step. CONCLUSION: Most of the predictive models produced similar results, and demonstrated the feasibility of identifying individuals with highest probability of having undiagnosed diabetes, through easily-obtained clinical data. RESUMO

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Repetitive indoor exercises as running on a treadmill or cycling on an exercise bike use to be tedious, meanwhile immersive virtual environments can bring a greater incentive especially when combined with other sources of motivation such as competition. In this work we introduce Running Wheel, an exergame with both single player and competitive modes with real time capture of heartbeat rhythm and speed of the treadmill. Two hypotheses were tested: (a) there is difference between users that ran with the competitive mode versus the single player mode; and (b) there is difference in performance depending on the kind of competitor picked. We evaluated the system with 12 volunteers which performed at least 6 jogging sessions. Results show that participants got strongly motivated and most of them tried to overcome their limitations and overtake others which in turn led to more effort, perceived by an increase in heartbeat rhythm.

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The computational module of several MPEG-based video encoders, which includes the known algorithms of Discrete Cosine Transform, Hadamard Transform and Quantization, is widely used to identify and compress spatial redundancy in intra (raw input) or inter (computed residue) data pixel matrices. For some modern multimedia applications, like high definition (HD H.264/AVC) or scalable (H.264/SVC) encoder solutions, the demand for fast module implementations becomes critical. Practical experiments indicate that, inside a H.264 computational module, the quantization module normally represents a real bottleneck for fast hardware implementations. Considering that we propose a complete integrated solution of H.264 computational module, which incorporates the direct and inverse algorithms of Discrete Cosine Transform, Hadamardand Quantization with minimal communication delays. Also in this paper it is presented a practical study, considering distinct levels of parallelism for the quantization to demonstrate its influence in order to optimize global encoder complexity and performance. All proposed alternatives were designed using hardware description language VHDL and implemented into commercial FPGA boards to obtain experimental results.

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The computational-intensive demands of H.264 video encoder normally imply to the use of high performance hardware solutions like dedicated multimedia DSP or programmable logic devices. These demands can be even more critical when it is necessary to implement a H.264/SVC (Scalable Video Coding) solution, an emergent encoder standard that provides the generation of flexible and adaptive multi-layer streams. The complexity of a SVC encoder increases proportionally with number of configured layers, introducing new challenges to multimedia market. In this work we propose an efficient hardware module, responsible for the transform algorithms (Hadamard and DCT) of a SVC encoder, processing up eight samples per clock. The proposed module take into account specific memory demands in order to produce an optimized solution with respect to encoder performance and complexity, aiming to reach a realizable SVC encoder.

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