Human-human multi-threaded spoken dialogs in the presence of driving

The problem addressed in this research is that engineers looking for interface designs do not have enough data about the interaction between multi-threaded dialogs and manual-visual tasks. Our goal was to investigate this interaction. We proposed to analyze how humans handle multi-threaded dialogs while engaged in a manual-visual task. More specifically, we looked at the interaction between performance on two spoken tasks and driving. The novelty of this dissertation is in its focus on the intersection between a manual-visual task and a multi-threaded speech communication between two humans. We proposed an experiment setup that is suitable for investigating multi-threaded spoken dialogs while subjects are involved in a manual-visual task. In our experiments one participant drove a simulated vehicle while talking with another participant located in a different room. The participants communicated using headphones and microphones. Both participants performed an ongoing task, which was interrupted by an interrupting task. Both tasks, the ongoing task and the interrupting task, were done using speech. We collected corpora of annotated data from our experiments and analyzed the data to verify the suitability of the proposed experiment setup. We found that, as expected, driving and our spoken tasks influenced each other. We also found that the timing of interruption influenced the spoken tasks. Unexpectedly, the data indicate that the ongoing task was more influenced by driving than the interrupting task. On the other hand, the interrupting task influenced driving more than the ongoing task. This suggests that the multiple resource model [1] does not capture the complexity of the interactions between the manual-visual and spoken tasks. We proposed that the perceived urgency or the perceived task difficulty plays a role in how the tasks influence each other

Electrocaloric Response of the Dense Ferroelectric Nanocomposites

Using the Landau-Ginzburg-Devonshire approach and effective media models, we calculated the spontaneous polarization, dielectric, pyroelectric, and electrocaloric properties of BaTiO$_3$ core-shell nanoparticles. We predict that the synergy of size effects and Vegard stresses can significantly improve the electrocaloric cooling (2- 7 times) of the BaTiO$_3$ nanoparticles with diameters (10-100) nm stretched by (1-3)% in comparison with a bulk BaTiO$_3$. To compare with the proposed and other known models, we measured the capacitance-voltage and current-voltage characteristics of the dense nanocomposites consisting of (28 -35) vol.% of the BaTiO$_3$ nanoparticles incorporated in the poly-vinyl-butyral and ethyl-cellulose polymers covered by Ag electrodes. We determined experimentally the effective dielectric permittivity and losses of the dense composites at room temperature. According to our analysis, to reach the maximal electrocaloric response of the core-shell ferroelectric nanoparticles incorporated in different polymers, the dense composites should be prepared with the nanoparticles volume ratio of more than 25 % and fillers with low heat mass and conductance, such as Ag nanoparticles, which facilitate the heat transfer from the ferroelectric nanoparticles to the polymer matrix. In general, the core-shell ferroelectric nanoparticles spontaneously stressed by elastic defects, such as oxygen vacancies or any other elastic dipoles, which create a strong chemical pressure, are relevant fillers for electrocaloric nanocomposites suitable for advanced applications as nano-coolers.Comment: 38 pages, including 10 figures and 2 appendixe