Abstract Objective: Describing the results of a User-Centered Design workshop using Challenge Based Learning or CBL, where students from Chilean industrial design and health degrees, developed solutions to resolve health problems among the elderly. Method: It was a pre-experimental study; 45 university students took part in a workshop: 39 from Industrial Design, 3 from Speech Therapy, 2 from Medical Technology and 1 from Medicine. In this workshop, the students, using CBL in disciplinary heterogeneous groups, faced a 3-week challenge to develop products to overcome a health problem for an elderly person. Once the product was presented, the professors and students assessed the conceptual proposals, using a semantic differential. The students also evaluated the workshop with a perception survey. Results: Both the students and professors positively evaluated the usefulness and functionality of the conceptual proposals; although, the industrial design students were more critical about these aspects. The originality of proposals evaluated was the worst. Regarding the workshop, all students (100%) felt that instructions were clear as were the three moments of design, with problem definition stage best evaluated. Conclusions: The CBL is shown to be an educational tool that allows training professionals in product design and in developing health technology that is suitable for the users' needs. Regarding the process, heterogeneous make-up of the groups and clear external guide appear as essential for CBL to work well. Keywords: challenge-based learning, elderly, interdisciplinary, higher education. Continuous...

The concept of urban metabolism was introduced by Wolman in 1965 [1], following insights and suggestions coming from ancient Marxism and the early ecologist theories.

We consider the discretization of continuous-time nonlinear systems described by normal forms. In particular, we consider the case when the input to the system is generated by a B-spline hold device to obtain an approximate discrete-time model. It is shown that the corresponding sampled-data model and its accuracy (measured in terms of the local truncation error) depend on the smoothness of the input and on the applied integration strategy, namely, the truncated Taylor series expansion. Moreover, the sampling zero dynamics of the discrete-time model are asymptotically characterized as the sampling period goes to zero, and it is shown that these zero dynamics converge to the asymptotic sampling zeros of the linear case.

This work presents a partial power converter allowing us to obtain, with a single DC-DC converter, the same feature as the classical interleaved operation of two converters. More precisely, the proposed topology performs similarly as the input-parallel output-series (IPOS) configuration reducing the current ripple at the input of the system and dividing the individual converters power rating, compared to a single converter. The proposed topology consists of a partial DC-DC converter processing only a fraction of the total power, thus allowing high efficiency. Experimental results are provided to validate the proposed converter topology with a Flyback-based 100 W test bench with a transformer turns ratio n 1 = n 2 . Experimental results show high performances reducing the input current ripple around 30 % , further increasing the conversion efficiency.