243 research outputs found
Impacte de l'ús de videojocs als alumnes de cicles formatius de la família d'informàtica
Aquest Treball Fi de Màster és un estudi sobre els efectes que tenen l'ús dels videojocs en alumnes del Cicle Formatiu de Grau Mitjà de Sistemes Microinformàtics i Xarxes d'un centre de Formació Professional concret. Inicialment es realitza una petita descripció, recull històric i es donen dades sobre la indústria dels videojocs. Posteriorment es realitza un resum de l'article The multiple dimensions of video game effects, del Douglas A. Gentile, que servirà de base teòrica per realitzar un anàlisis dels efectes dels videojocs. A través de la realització d'una enquesta sobre els hàbits d'ús de videojocs i sobre altres hàbits dels estudiants, s'obtindran uns resultats que posteriorment serviran per a realitzar una sèrie de propostes d'activitats a aplicar al centre de formació professional
Super-stretchable paper-based materials for 3D forming
Paper is renewable, recyclable, sustainable and biodegradable material and, as a result, paper-based materials are widely used in the world packaging market. However, paper-based materials cannot compete with plastics in terms of processability into various 3D shapes. This is due to poor formability of paper, which is closely associated with its toughness. To improve paper formability, we report on a facile and green method that combines fiber and paper mechanical modifications at different structural levels as well as biopolymer treatment via spraying. As a result, a remarkable elongation of ∼30% was achieved after proposed combined approach on the laboratory scale. At the same time, a significant increase in tensile strength and stiffness (by ∼306% and ∼690%, respectively) was observed. Overall, an inexpensive, green, and scalable approach is introduced to improve formability of fiber networks that in turn allows preparation of 3D shapes in the processes with fixed paper blanks such as vacuum forming, hydroforming, hot pressing, etc
Multi-stage tensile straining during drying of SC paper
During multi-cylinder drying on a paper machine, the paper web is under stress in the machine direction, whereas the cross direction is more or less free. The web shrinks due to drying and contracts due to web draws. The machine speed, dryness and tension level determine the speed difference between drive groups, which in turn determines the level of MD straining. Straining and stresses during drying have a significant influence on the elastic properties of paper. The objective of this study was to investigate the effects of multi-stage straining during drying on the tensile properties of dried paper.Oriented SC paper samples were prepared on a pilot paper machine with varying levels of draw between the press and the press cylinders. Never-dried SC paper samples were then dried in a C-Impact laboratory tensile tester. The tensile force, strain, surface temperature and dryness of the samples were measured during drying.The design of the trials was full factorial (multivariate), which enabled the use of statistical methods in the data analysis. Two of the five straining tests were performed on a pilot paper machine during sample preparation, and three of the five during drying on a laboratory tester. The draws were combined in order to form two separate 34 full factorial designs. It was concluded that the use of a fractional factorial design instead of a full factorial design would lead to equally statistically good results, but would also be biased towards the most powerful factor term.The measured tension of the paper samples during drying was affected by the straining, dryness and tension relaxation of the paper. The straining and drying history of the paper also influenced the tensile properties. Increased straining generally led, almost linearly, to decreased strain at break of the dried paper. The tensile stiffness of the dried paper and the drying tension at the end of drying (final drying tension) were increased considerably by straining. Although a certain level of strain is needed to ensure wet web runnability, straining has a detrimental effect on a number of dry paper web properties. Straining strategy improvements can be made by controlling the dryness of straining. The C-Impact tensile tester was found to realistically simulate the paper drying process at paper machine conditions
Analyse de l'erreur en vérification probabiliste
La vérification de systèmes est aujourd’hui un sujet de recherche récurrent et différentes techniques permettent de vérifier formellement des systèmes critiques dont il faut impérativement garantir la correction. Nous consacrons ce mémoire à l’une des techniques les plus utilisées et les plus efficaces, l’évaluation de modèle. Schématiquement, pour vérifier un système par évaluation de modèle, on abstrait d’abord son comportement sous la forme d’un système de transitions appelé modèle. Ensuite, on formule une propriété désirée du système dans une logique temporelle. Enfin, on utilise un outil logiciel appelé vérificateur pour vérifier automatiquement si le modèle satisfait la propriété. Dans ce mémoire, nous voulons vérifier des propriétés d’atteignabilité dans des modèles probabilistes appelés processus de Markov étiquetés (en anglais, LMP pour Labelled Markov processes) et qui ont possiblement un ensemble d’états non dénombrable. Malheureusement, le vérificateur CISMO dédié à une famille de LMP ne gère pas les propriétés d’atteignabilité et aucun autre outil ne peut vérifier les LMP. Pour améliorer CISMO et atteindre notre objectif, nous avons rendu d’abord plus expressive sa logique de spécification de propriétés pour qu’elle exprime les propriétés d’atteignabilité sur les LMP. Ces propriétés expriment le fait qu’un état souhaité dans un système peut être atteint avec une certaine probabilité. Ensuite, nous avons implémenté dans CISMO une nouvelle approche de vérification d’une famille de propriétés d’atteignabilité qui contribue à l’évolution de la vérification probabiliste. Nous utilisons le théorème de la moyenne pour prouver que, pour tout LMP acceptable par CISMO et toute propriété d’atteignabilité, il existe une chaîne de Markov à temps discret (en anglais, DTMC pour Discrete Time Markov Chains) équivalent au LMP de point de vue atteignabilité moyenne et auquel on peut appliquer les algorithmes connus pour les systèmes probabilistes finis. Le DTMC est construit de telle sorte que nous inférons que le LMP satisfait la propriété d’atteignabilité, si et seulement si le DTMC la satisfait. Théoriquement, notre approche donne un résultat ultime exact et nous l’avons prouvé. À l’implémentation, nous utilisons une méthode d’intégration numérique pour déterminer les probabilités de transition dans le DTMC. Malgré les imprécisions numériques qui peuvent nuire au résultat d’une vérification, nous avons prouvé que notre approche a du sens en quantifiant les erreurs. Nous avons démontré d’une part que les erreurs numériques sont toujours bornées supérieurement dans le DTMC et avons montré d’autre part, qu’il existe une relation de bisimulation entre le LMP et le DTMC. Notre méthode est originale et repousse les limites de l’évaluation de modèle, notamment l’explosion combinatoire de l’espace d’états ou de chemins dans la vérification de systèmes probabilistes infinis.Systems verification is nowadays a major issue and various techniques verify formally critical systems for which correction must be ensured. The focus of this master’s thesis is on one of the most used and most effective systems verification techniques, modelchecking. Conceptually, to apply model-checking to a system, we first abstract its behavior in the form of a transitions system, the model. Then, we formulate a system property of interest in a temporal logic. Finally, a software called model-checker is used to verify automatically if the model satisfies the property. In this paper, we want to check reachability property in the probabilistic models called labelled Markov process (LMP) and which have possibly an uncountable set of states. Unfortunately, the model-checker CISMO dedicated to a family of LMP does not handle reachability properties and no other tool can verify LMP. To improve CISMO and achieve our goal, we first made more expressive its properties specification logic so that it can express reachability property on LMP. These properties express the fact that a desired state in a system can be reached with a certain probability. Secondly, we implemented in CISMO a new approach for the verification of a family of reachability properties. This is a contribution to the evolution of the probabilistic verification. We use the mean theorem to prove that, for any LMP acceptable by CISMO and for any reachability property, there is a discrete time process (DTMC) equivalent to the LMP according to the average reachability and on which we can apply known algorithms for probabilistic systems which have a countable set of states. The DTMC is constructed in such a way that we can infer the LMP satisfies the reachability property, if and only if the DTMC also satisfies it. Theoretically, our approach gives a precise final result and we prove it. At implementation, since the DTMC is subjected to numerical errors the result can be false, as expected. We use a numerical integration method to determine the transitions probabilities in the DTMC. Despite the errors that can affect the outcome of a verification, we have shown that our approach makes sense at implementation by quantifying the errors. We have shown on one hand that numerical errors are always bounded from above in the DTMC and we established, on the other hand, bisimulation relations between LMP, DTMC constructed theoretically, and DTMC generated algorithmically with errors. Our method is original and pushes the limits of model-checking, especially combinatorial explosion of the states space or paths in the verification of infinite probabilistic systems
The meaning of life for an elderly man living alone : a narrative approach
Aim: To improve nursing care for the elderly in order to allow them to live independently. This study has used the narrative of an elderly man to learn about what has given his life meaning.Method: Fifteen key concepts were extracted from interviews using the narrative approach.Results and Conclusions: Mr. A, now near the end of his life, has found meaning in living his life, not only for himself, but also for those around him. The elderly support their own physical and mental health,and adjust to day-to-day life. Nursing care for the elderly should watch for and support these self-supporting efforts
上顎の形態発生におけるWnt signaling pathwayの役割
Cleft lip with or without cleft palate (CLP) usually results from a failure of the medial nasal prominences to fuse with the lateral and maxillary prominences. This failure inhibits facial morphogenesis regulated by several major morphogenetic signaling pathways. We hypothesized that CLP results from the failure of the Wnt signaling pathway. To examine whether Wnt signaling can influences upper jaw development, we applied beads soaked with Dickkopf-1 (Dkk-1), Alsterpaullone (AL) or Wnt3a to the right side of the maxillary prominence of the chick embryo. The embryo showed a defect of the maxilla on the treated side, and skeletal staining revealed hypoplasia of the premaxilla and palatine bone as a result of Dkk-1-soaked bead implantation. 5-bromo-2'-deoxyuridine (BrdU)-positive cell numbers in the treated maxillary prominence were significantly lower at both 24 and 48 hr after implantation. Down-regulation of the expression of Bmp4, Tbx22, Sox9, and Barx1 was confirmed in the maxillary prominence treated with Dkk-1, which indicated that the deformity of the maxillary bone was controlled by gene targets of the Wnt signaling pathway. Expression of N-cadherin was seen immunohistochemically in the maxillary prominences of embryos at 6 hr and increased at 24 hr after AL treatment. Wnt signaling enhanced by AL or Wnt3a up-regulated the expression levels of Msx1, Bmp4, Tbx22, Sox9, and Barx1. Our data suggest that the Wnt signaling pathway regulates maxillary morphogenesis and growth through Bmp4, Tbx22, Sox9, and Barx1. Wnt signaling might regulate N-cadherin expression via Msx1, resulting in cell aggregation for osteochondrogenesis.博士(医学)・乙第1430号・令和元年6月26日© 2019 The Japan Society of Histochemistry and CytochemistryCopyright: © 2019 The author. This is an open access article distributed under the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, istribution, and reproduction in any medium, provided the original work is properly cited.J-STAGEへのリンク : http://dx.doi.org/10.1267/ahc.1803
- …