Capturing entertainment through heart rate dynamics in the playware playground

This paper introduces a statistical approach for capturing entertainment in real-time through physiological signals within interactive playgrounds inspired by computer games. For this purpose children’s heart rate (HR) signals and judgement on entertainment are obtained from experiments on the innovative Playware playground. A comprehensive statistical analysis shows that children’s notion of entertainment correlates highly with their average HR during the game.peer-reviewe

Preliminary studies for capturing entertainment through physiology in physical play

This report presents preliminary physical control experiments for capturing and modeling the affective state of entertainment — that is, whether people are having "fun" — of users of the innovative Play-ware playground, an interactive physical playground. The goal is to con-struct, using representative statistics computed from children's physio-logical hear rate (HR) signals, an estimator of the degree to which games provided by the playground engage the players. For this purpose chil-dren's HR signals, and their expressed preferences of how much "fun" particular game variants are, are obtained from experiments using games implemented on the Playware playground. Neuro-evolution techniques combined with feature set selection methods permit the construction of user models that predict reported entertainment preferences given HR features. These models are expressed as artificial neural networks and are demonstrated and evaluated on two Playware games and the pre-liminary control task requiring physical activity. Results demonstrate that the proposed preliminary control experiment is not an appropriate control for physical activity effects since it may generate HR dynamics rather easy to separate from game-play HR dynamics, and allows one to distinguish entertaining game-play from exercise purely on the artificial basis of the kind of physical activity taking place. Conclusions derived from this study constitute the basis for the design of more appropriate control experiments and user models in future studies.peer-reviewe

Don't classify ratings of affect ; rank them!

How should affect be appropriately annotated and how should machine learning best be employed to map manifestations of affect to affect annotations? What is the use of ratings of affect for the study of affective computing and how should we treat them? These are the key questions this paper attempts to address by investigating the impact of dissimilar representations of annotated affect on the efficacy of affect modelling. In particular, we compare several different binary-class and pairwise preference representations for automatically learning from ratings of affect. The representations are compared and tested on three datasets: one synthetic dataset (testing “in vitro”) and two affective datasets (testing “in vivo”). The synthetic dataset couples a number of attributes with generated rating values. The two affective datasets contain physiological and contextual user attributes, and speech attributes, respectively; these attributes are coupled with ratings of various affective and cognitive states. The main results of the paper suggest that ratings (when used) should be naturally transformed to ordinal (ranked) representations for obtaining more reliable and generalisable models of affect. The findings of this paper have a direct impact on affect annotation and modelling research but, most importantly, challenge the traditional state-of-practice in affective computing and psychometrics at large.peer-reviewe

National geotechnical centrifuge

A high G-ton centrifuge, able to take a 2700 kg (6000 lb) payload up to 300 G, is described. The stability of dams and embankments, the bearing capacity of soil foundations, and the dynamic behavior of foundations due to vibration of machinery are examples of applications. A power rating of 6,000 kW (9,000 hp) was established for the motor. An acceptable maximum speed of 70 rpm was determined. A speed increase with a ratio of 1:3 is discussed. The isolated tension straps, the anti-spreader bar and the flexwall bucket, and safety precautions are also discussed

Salinity effects on nutrients uptake, biochemical content and growth response of Blue Panic (Panicum antidotale Retz) and Silage maize (Zea mays L)

Les cultures alternatives tolérantes à la salinité développent des mécanismes complexes dans les conditions biosalines. Nous avons étudié l'effet de l'eau salée sur l'absorption des nutriments et les paramètres physiologiques et biochimiques du bleu panicum (Panicum antidotale Retz) et du maïs d’ensilage (Zea mays L). Des mésocosmes ont été établis en quatre répétitions pour chaque espèce de plante dans une conception orthogonale avec différents niveaux d'eau d'irrigation saline comme traitements donnant T0 = 0.9 dS.m-1 (eau du robinet), T1 = 3 dS m-1, T2 = 6 dS m-1 et T3 = 10 dS m-1, pendant 8 semaines. L'augmentation de la salinité a provoqué un effet dépressif sur le maïs d’ensilage, conduisant à une réduction significative de la croissance (jusqu'à 37%), de la biomasse aérienne sèche (jusqu'à 58%) et racinaire (jusqu'à 87%) par rapport au témoin. Ainsi qu'une diminution de la chlorophylle a (jusqu'à 71 %), de la chlorophylle b (jusqu'à 77 %) et des caroténoïdes (jusqu'à 49 %) par rapport au témoin. Pour le bleu panicum, la salinité n'a par contre pas affecté les paramètres physiologiques et biochimiques étudiés. L'absorption de l’azote, du phosphore, du potassium et du calcium, du maïs d’ensilage a diminué avec l'augmentation des niveaux de salinité pour être significative pour une eau d'irrigation avec une conductivité électrique ≥ 6 dS m-1 par rapport au contrôle. La teneur en sodium dans les différentes parties du maïs d’ensilage (feuille, tige et racine), par contre, a augmenté significativement avec l'augmentation de la salinité. L'accumulation du calcium, du potassium et de l’azote a légèrement augmenté chez le bleu panicum, mais n’était significatif que dans des parties distinctes de la plante. Dans l'ensemble, notre étude indique que le maïs est plus sensible aux conditions salines (notamment celles ≥ 6 dS m-1) par rapport au bleu panicum qui tolère bien un environnement de salinité élevé ≥ 10 dS.m-1. Nos résultats suggèrent ainsi que l'introduction du bleu panicum comme culture alternative sur les sols affectés par la salinité, comme le périmètre irrigué de Foum El Oued à Laâyoune au Maroc, résulterait en des rendements élevés meilleurs que les rendements des cultures traditionnelles comme le maïs d’ensilage et améliorerait donc le revenu des agriculteurs locaux.Saline-tolerant alternative crops develop complex mechanisms under biosaline conditions. We investigated the effect of saline water on nutrient uptake, physiological and biochemical parameters of Blue Panic (Panicum antidotale Retz) and silage maize (Zea mays L). Mesocosms were established in four replicates for each plant species in an orthogonal design with different levels of saline irrigation water as treatments giving T0 = 0.9 dS m-1 (tap water), T1 = 3 dS m -1, T2 = 6 dS m-1 and T3 = 10 dS m-1, for 8 weeks. Increasing salinity caused a depressive effect on silage maize's physiological parameters, leading to a significant decrease in growth (up to 37%), aboveground (up to 58%) and root (up to 87%) dry matter biomass compared to control. As well as a decrease of chlorophyll a (up to 71%), chlorophyll b (up to 77%) and carotenoid (up to 49%) compared to control. For blue panic, salinity did not, however, affect the studied physiological and biochemical parameters. Nitrogen, phosphorus, potassium and calcium uptake, of silage maize, decreased with increasing salinity levels to be significant in irrigation water with electrical conductivity ≥ 6 dS m-1 relative to control. The sodium content in different parts of silage maize (leaf, stem and root), on the other hand, increased significantly with increasing salinity. The accumulation of calcium, potassium and nitrogen increased slightly in the blue panic, but this was only significant in separate parts of the plant. Overall, our study indicates that silage maize is more sensitive to saline conditions (particularly ≥ 6 dS m-1) compared to blue panic which tolerates well high saline environment ≥ 10 dS m-1. Our results, suggest therefore that the introduction of blue panic as an alternative crop on salt affected soils, such as the irrigated perimeter of Foum El Oued in Laâyoune in Morocco, would exhibit high performance better than traditional crops as silage maize and therefore would improve the local farmers’ income

The incidence and make up of ability grouped sets in the UK primary school

The adoption of setting in the primary school (pupils ability grouped across classes for particular subjects) emerged during the 1990s as a means to raise standards. Recent research based on 8875 children in the Millennium Cohort Study showed that 25.8% of children in Year 2 were set for literacy and mathematics and a further 11.2% of children were set for mathematics or literacy alone. Logistic regression analysis showed that the best predictors of being in the top set for literacy or mathematics were whether the child was born in the Autumn or Winter and cognitive ability scores. Boys were significantly more likely than girls to be in the bottom literacy set. Family circumstances held less importance for setting placement compared with the child’s own characteristics, although they were more important in relation to bottom set placement. Children in bottom sets were significantly more likely to be part of a long-term single parent household, have experienced poverty, and not to have a mother with qualifications at NVQ3 or higher levels. The findings are discussed in relation to earlier research and the implications for schools are set out

An evolutionary approach for interactive computer games

The authors would like to thank Jeong Keun Park for his valuable contribution to the graphical representation of the Dead End game.In this paper we introduce the first stage of experiments on neuro-evolution mechanisms applied to predator/prey multi-character computer games. Our test-bed is a computer game where the prey (i.e. player) has to avoid its predators by escaping through an exit without getting killed. By viewing the game from the predators’ (i.e. opponents’) perspective, we attempt off-line to evolve neural-controlled opponents capable of playing effectively against computer-guided fixed strategy players. Their efficiency is based on cooperation which emerges from an abstract type of partial interaction with their environment. In addition, investigation of behavior generalization demonstrated the crucial contribution of playing strategies in the development of successful predator behaviors. However, emergent well-behaved opponents trained off-line with fixed strategies do not make the game interesting to play. We therefore present an evolutionary mechanism for opponents that keep learning from a player while playing against it (i.e. on-line) and we demonstrate its efficiency and robustness in increasing the predators’ performance while altering their behavior as long as the game is played. Computer game opponents following this on-line learning approach show high adaptability to changing player strategies, which provides evidence for the approach’s effectiveness and interest against human players.peer-reviewe

Entertainment modeling in physical play through physiology beyond heart-rate

An investigation into capturing the relation of physiology, beyond heart rate recording, to expressed preferences of entertainment in children’s physical gameplay is presented in this paper. An exploratory survey experiment raises the difficulties of isolating elements derived (solely) from heart rate recordings attributed to reported entertainment and a control experiment for surmounting those difficulties is proposed. Then a survey experiment on a larger scale is devised where more physiological signals (Blood Volume Pulse and Skin Conductance) are collected and analyzed. Given effective data collection a set of numerical features is extracted from the child’s physiological state. A preference learning mechanism based on neuro-evolution is used to construct a function of single physiological features that models the players’ notion of ‘fun’ for the games under investigation. Performance of the model is evaluated by the degree to which the preferences predicted by the model match those expressed by the children. Results indicate that there appears to be increased mental/emotional effort in preferred games of children.peer-reviewe

Towards optimizing entertainment in computer games

Mainly motivated by the current lack of a qualitative and quantitative entertainment formulation of computer games and the procedures to generate it, this article covers the following issues: It presents the features—extracted primarily from the opponent behavior—that make a predator/prey game appealing; provides the qualitative and quantitative means for measuring player entertainment in real time, and introduces a successful methodology for obtaining games of high satisfaction. This methodology is based on online (during play) learning opponents who demonstrate cooperative action. By testing the game against humans, we confirm our hypothesis that the proposed entertainment measure is consistent with the judgment of human players. As far as learning in real time against human players is concerned, results suggest that longer games are required for humans to notice some sort of change in their entertainment.peer-reviewe

Rating vs. preference : a comparative study of self-reporting

This paper introduces a comparative analysis between rating and pairwise self-reporting via questionnaires in user survey experiments. Two dissimilar game user survey experiments are employed in which the two questionnaire schemes are tested and compared for reliable affect annotation. The statistical analysis followed to test our hypotheses shows that even though the two self-reporting schemes are consistent there are significant order of reporting effects when subjects report via a rating questionnaire. The paper concludes with a discussion of the appropriateness of each self-reporting scheme under conditions drawn from the experimental results obtained.peer-reviewe