Virtual Assistants for End-User Development in the Internet of Things

The spread of Virtual Assistants (software and hardware) on the consumer market deeply changed the way Internet of Things (IoT) is implemented and used today. Such devices, and related applications, are becoming more and more integrated within smart environments and this might pave the way to potential new approaches to End-User Development activities, which can be performed in IoT environments. This paper discusses the evolution of the IoT ecosystem definition that has been studied by the authors in the last years

Nonlinear dynamic response and modeling of a bi-stable composite plate for applications to adaptive structures

This paper discusses the formulation and validation of a low order model to capture the dynamics of a bi-stable composite plate, focusing on the dynamics around its stable states. More specifically, the model aims to capture the complex nonlinear subharmonic behavior observed in the dynamic response of the plate. A system identification approach is used to derive simplified equations of motion for the system. Experimental frequency response diagrams are obtained to characterize the observed dynamics in the identification process. Simulations using the identified model are presented showing excellent agreement with the experimentally observed behavior. A theoretical validation of the model is carried out studying the stability of the modes where subharmonic response was observed. Stability boundaries were computed using averaging techniques showing good agreement with experimental results

A generalized frequency detuning method for multidegree-of-freedom oscillators with nonlinear stiffness

In this paper, we derive a frequency detuning method for multi-degree-of-freedom oscillators with nonlinear stiffness. This approach includes a matrix of detuning parameters, which are used to model the amplitude dependent variation in resonant frequencies for the system. As a result, we compare three different approximations for modeling the affect of the nonlinear stiffness on the linearized frequency of the system. In each case, the response of the primary resonances can be captured with the same level of accuracy. However, harmonic and subharmonic responses away from the primary response are captured with significant differences in accuracy. The detuning analysis is carried out using a normal form technique, and the analytical results are compared with numerical simulations of the response. Two examples are considered, the second of which is a two degree-of-freedom oscillator with cubic stiffnesses

Study of the Structure of Hyperbranched Polyglycerol Coatings and Their Antibiofouling and Antithrombotic Applications

While blood‐contacting materials are widely deployed in medicine in vascular stents, catheters, and cannulas, devices fail in situ because of thrombosis and restenosis. Furthermore, microbial attachment and biofilm formation is not an uncommon problem for medical devices. Even incremental improvements in hemocompatible materials can provide significant benefits for patients in terms of safety and patency as well as substantial cost savings. Herein, a novel but simple strategy is described for coating a range of medical materials, that can be applied to objects of complex geometry, involving plasma‐grafting of an ultrathin hyperbranched polyglycerol coating (HPG). Plasma activation creates highly reactive surface oxygen moieties that readily react with glycidol. Irrespective of the substrate, coatings are uniform and pinhole free, comprising O─C─O repeats, with HPG chains packing in a fashion that holds reversibly binding proteins at the coating surface. In vitro assays with planar test samples show that HPG prevents platelet adhesion and activation, as well as reducing (>3 log) bacterial attachment and preventing biofilm formation. Ex vivo and preclinical studies show that HPG‐coated nitinol stents do not elicit thrombosis or restenosis, nor complement or neutrophil activation. Subcutaneous implantation of HPG coated disks under the skin of mice shows no evidence of toxicity nor inflammation

EU Structural Funds and Regional Income Convergence A Sobering Experience

The European Structural and Investment Funds (ESIF) are the prime instrument of EU regional policy. European policy makers place considerable hope into their growth stimulating funding measures to overcome current economic stagnation. Consequently, there is a strong need for credible evidence regarding the programs' effectiveness. Based on an empirical identification strategy linked to modern growth theory, we find that the disbursement of EU structural funds is negatively correlated with regional growth. Incorporating spatial dynamics and decomposing this correlation into a direct and a spatially-indirect component, it is particularly the latter which determines this 'sobering' finding. Regarding the economics behind these results, the obtained negative spatial effect may reflect the role played by policy-induced spatial competition among neighboring regions. It could also highlight the backwardness in technological endowment and economic structures of highly funded regions. In any case, EU structural funding does not seem to contribute effectively to foster income convergence across regions.Die europäischen Struktur und Investmentfonds (ESIF) sind das wichtigste Instrument der EU-Regionalpolitik; die europäische Politik setzt große Hoffnungen in die wachstumsstimulierende Wirkung dieser Fördermaßnahmen zur Überwindung der aktuellen wirtschaftlichen Stagnation. Basierend auf einer empirischen Identifikationsstrategie können in diesem Papier keine Belege für positive Förderwirkungen gefunden werden. Werden räumliche Strukturen berücksichtigt, zeigt sich, dass räumlich indirekte Effekte dieses Ergebnis beeinflussen - also solche Regionen weniger wachsen, deren Nachbarn stark gefördert werden. Neben der potenziellen Erklärung, dass Nachbarn gegenseitig ihre Investoren abwerben, legt dieses Resultat nahe, dass hochgeförderte regionale Cluster unter struktureller und technologischer Rückständigkeit leiden, die durch Wachstumsprogramme nicht überwunden werden. Beide möglichen Erklärungen lassen den Schluss zu, dass die Förderung ihr eigentliches Ziel, die Konvergenz der Regionen, verfehlt