A POMDP approach to Affective Dialogue Modeling

We propose a novel approach to developing a dialogue model that is able to take into account some aspects of the user's affective state and to act appropriately. Our dialogue model uses a Partially Observable Markov Decision Process approach with observations composed of the observed user's affective state and action. A simple example of route navigation is explained to clarify our approach. The preliminary results showed that: (1) the expected return of the optimal dialogue strategy depends on the correlation between the user's affective state & the user's action and (2) the POMDP dialogue strategy outperforms five other dialogue strategies (the random, three handcrafted and greedy action selection strategies)

A tractable DDN-POMDP Approach to Affective Dialogue Modeling for General Probabilistic Frame-based Dialogue Systems

We propose a new approach to developing a tractable affective dialogue model for general probabilistic frame-based dialogue systems. The dialogue model, based on the Partially Observable Markov Decision Process (POMDP) and the Dynamic Decision Network (DDN) techniques, is composed of two main parts, the slot level dialogue manager and the global dialogue manager. Our implemented dialogue manager prototype can handle hundreds of slots; each slot might have many values. A first evaluation of the slot level dialogue manager (1-slot case) showed that with a 95% confidence level the DDN-POMDP dialogue strategy outperforms three simple handcrafted dialogue strategies when the user's action error is induced by stress

Particle-stabilized oscillating diver: a self-assembled responsive capsule

We report the experimental discovery of a self-assembled capsule, with density set by interfacial glass beads and an internal bubble, that automatically performs regular oscillations up and down a vial in response to a temperature gradient. Similar composites featuring interfacial particles and multiple internal compartments could be the solution to a variety of application challenges.Comment: 7 pages, 3 figure

Emulsification in binary liquids containing colloidal particles: a structure-factor analysis

We present a quantitative confocal-microscopy study of the transient and final microstructure of particle-stabilised emulsions formed via demixing in a binary liquid. To this end, we have developed an image-analysis method that relies on structure factors obtained from discrete Fourier transforms of individual frames in confocal image sequences. Radially averaging the squared modulus of these Fourier transforms before peak fitting allows extraction of dominant length scales over the entire temperature range of the quench. Our procedure even yields information just after droplet nucleation, when the (fluorescence) contrast between the two separating phases is scarcely discernable in the images. We find that our emulsions are stabilised on experimental time scales by interfacial particles and that they are likely to have bimodal droplet-size distributions. We attribute the latter to coalescence together with creaming being the main coarsening mechanism during the late stages of emulsification and we support this claim with (direct) confocal-microscopy observations. In addition, our results imply that the observed droplets emerge from particle-promoted nucleation, possibly followed by a free-growth regime. Finally, we argue that creaming strongly affects droplet growth during the early stages of emulsification. Future investigations could clarify the link between quench conditions and resulting microstructure, paving the way for tailor-made particle-stabilised emulsions from binary liquids.Comment: http://iopscience.iop.org/0953-8984/22/45/455102

Welfarism vs. extra-welfarism

'Extra-welfarism' has received some attention in health economics, yet there is little consensus on what distinguishes it from more conventional 'welfarist economics'. In this paper, we seek to identify the characteristics of each in order to make a systematic comparison of the ways in which they evaluate alternative social states. The focus, though this is not intended to be exclusive, is on health. Specifically, we highlight four areas in which the two schools differ: (i) the outcomes considered relevant in an evaluation; (ii) the sources of valuation of the relevant outcomes; (iii) the basis of weighting of relevant outcomes and (iv) interpersonal comparisons. We conclude that these differences are substantive. (C) 2007 Elsevier B.V. All rights reserved

The perseverance time of informal carers for people with dementia: Results of a two-year longitudinal follow-up study

Background: Given the projected increase of people with dementia over the next few decades and the related demand for informal care, an important question for health policy makers is to what extent and for how long informal carers can be expected to provide care in a sustainable way. This study aimed to investigate the perseverance time of informal carers for people with dementia. Methods: A 2-year longitudinal cohort study was conducted. Questionnaires were used to collect data about the care situation, the impact of caregiving on carers and their need for support, and the anticipated and realized perseverance time of informal carers for people with dementia living at home. The data were analysed using bivariate and multivariate analyses. Results: Two hundred twenty-three carers for people with dementia were included in the study and 25 (11.2 %) dropped out during the follow-up. The results show that after 1 year, 74 (37.4 %) of 198 patients were still living at home, and after 2 years, 44 (22.2 %) patients were still living at home. The variables that were associated with this outcome were identified. When informal carers anticipated that their perseverance time would be less than 1 year, this was indicative of their actual perseverance time. Conclusions: Anticipated perseverance time provides a fair indication of the actual duration of informal care. It is most accurate when carers anticipate a limited rather than an unlimited perseverance time. Although further research is required to support these findings, the concept of perseverance time may be considered a useful additional instrument in health policy and clinical practice for monitoring carers' need for support and for planning the transition of care from home to a nursing home

La conductivité électro-magnétique : application au suivi de la salinité des sols des périmètres irrigués de Tunisie

Le but de la mission était de présenter une méthode d'évaluation de la salinité des sols par conductivimétrie électromagnétique et de tester dans les conditions de la Tunisie son application à la cartographie de la salure des périmètres irrigués du territoire. La présentation de l'appareillage a d'abord fait l'objet d'un séminaire à Sidi Thabet, organisé par la Direction des Sols. Puis quatre études de cas représentatifs ont été réalisées sur le terrain avec la collaboration des ingénieurs des laboratoires d'arrondissements de la Direction des Sols : périmètre de Sidi Saad (Kairouan), périmètre de Zelba (Mahdia), périmètre de Hazeg (Sfax), périmètre de Sebala ben Amar (Tunis). Au total plus de 700 mesures ont été réalisées au cours de la tournée soit sur la totalité de chaque périmètre, soit sur des parcelles représentatives (cf rapport technique). La facilité de mise en oeuvre de l'appareillage par rapport aux mesures habituelles avec prélèvements, la rapidité de la mesure qui est immédiate, la sensibilité de l'appareil même aux faibles salinités, l'appréhension d'une salinité globale permettant de s'affranchir du problème de variabilité spatiale, font de cette méthodologie une technique bien adaptée au suivi simultané d'un grand nombre de périmètres irrigués dans le cadre d'un réseau national de surveillance de la salinité des sols. (Résumé d'auteur

Economic Potential of Substituting Legumes for Synthetic Nitrogen in Warm Season Perennial Grasses used for Stocker Cattle Grazing

Stocker cattle grazing warm season perennial grasses is an important economic activity in the southern Great Plains. Substantial increases in the price of nitrogen fertilizer is negatively affecting forage producers’ profitability. Two alternative nitrogen management systems that use annual and perennial legumes have been developed for bermudagrass pastures. The goal of the study is to determine if the legumes systems are more profitable than the conventional practice of applying synthetic sources of nitrogen. Results of the two-year grazing study show that the legume systems could not compete economically with the common practice.economics, grazing, legumes, bermudagrass, nitrogen fertilizer, stocker cattle, Crop Production/Industries, Farm Management, Production Economics,