Concatenated linear systems over rings and their application to construction of concatenated families of convolutional codes

© 2017 Elsevier Inc. We present a generalization of the theory of concatenated linear systems to commutative rings with identity. Moreover, we highlight sufficient conditions to obtain reachable and observable concatenated linear systems. This approach provides us with minimal input-state-output representations by means of which we can construct observable concatenated families of convolutional codes with different parameters over some particular rings. This work focuses on the characterization of models of serial, systematic serial and parallel concatenation.Peer ReviewedPostprint (author's final draft

Concatenated linear systems over rings and their application to construction of concatenated families of convolutional codes

© 2017 Elsevier Inc. We present a generalization of the theory of concatenated linear systems to commutative rings with identity. Moreover, we highlight sufficient conditions to obtain reachable and observable concatenated linear systems. This approach provides us with minimal input-state-output representations by means of which we can construct observable concatenated families of convolutional codes with different parameters over some particular rings. This work focuses on the characterization of models of serial, systematic serial and parallel concatenation.Peer Reviewe

A motivational interview program for cardiac rehabilitation after acute myocardial infarction: study protocol of a randomized controlled trial in primary healthcare

Background: Cardiac rehabilitation after acute myocardial infarction permits recovery of the heart function and enables secondary prevention programs in which changes in lifestyle habits are crucial. Cardiac rehabilitation often takes place in hospitals without coordination with primary healthcare and is not focused on individual patient preferences and goals, which is the core of the motivational interview. The objective of this study was to evaluate the efficacy of a cardiac rehabilitation program with a motivational interview in patients discharged from hospital after acute myocardial infarction. Methods/design: A randomized, non-pharmacological clinical trial in six primary healthcare centers in Barcelona (Spain) will assess whether a tailored cardiac rehabilitation program consisting of four motivational interviews and visits with family physicians, primary healthcare nurses and a cardiologist, coordinated with the reference hospital, results in better cardiac rehabilitation than standard care. A minimum sample of 284 participants requiring cardiac rehabilitation after acute myocardial infarction will be randomized to a cardiac rehabilitation group with a motivational interview program or to standard primary healthcare. The main outcome will be physical function measured by the six-minute walk test, and the secondary outcome will be the effectiveness of secondary prevention: a composite outcome comprising control of blood pressure, cholesterol, diabetes mellitus, smoking and body weight. Results will be evaluated at 1,3 and 6 months. Discussion: This is the first clinical trial to study the impact of a new primary healthcare cardiac rehabilitation program with motivational interviews for patients discharged from hospital after myocardial infarction. Changes in lifestyles and habits after myocardial infarction are a core element of secondary prevention and require patient-centered care strategies such as motivational interviews. Therefore, this study could clarify the impact of this approach on health indicators, such as functional capacity