865 resultados para Susskind, Leonard: The Cosmic Landscape: string theory and the illusion of intelligent design


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This study evaluated the effect of framework design on the fracture resistance of metal-ceramic implant-supported crowns. Screw-retained molar crowns with a screw access hole composed of metal or porcelain were compared to a cement-retained crown (control). For each group (n = 10), five crowns were subjected to dynamic loading (1,200,000 x 100 N x 2 Hz at 37 degrees C). Afterward, all specimens were loaded to failure using a universal testing machine. Significant differences could be established between the cement-and screw-retained groups (P <= .05), but no difference was found between the screw-retained groups and the specimens subjected to dynamic loading. Occlusal discontinuity of screw-retained crowns affects their resistance, and the metallic support on the screw access hole did not reinforce the crowns. Int J Prosthodont 2010;23:350-352.

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Ergonomic interventions such as increased scheduled breaks or job rotation have been proposed to reduce upper limb muscle fatigue in repetitive low-load work. This review was performed to summarize and analyze the studies investigating the effect of job rotation and work-rest schemes, as well as, work pace, cycle time and duty cycle, on upper limb muscle fatigue. The effects of these work organization factors on subjective fatigue or discomfort were also analyzed. This review was based on relevant articles published in PubMed, Scopus and Web of Science. The studies included in this review were performed in humans and assessed muscle fatigue in upper limbs. 14 articles were included in the systematic review. Few studies were performed in a real work environment and the most common methods used to assess muscle fatigue were surface electromyography (EMG). No consistent results were found related to the effects of job rotation on muscle activity and subjective measurements of fatigue. Rest breaks had some positive effects, particularly in perceived discomfort. The increase in work pace reveals a higher muscular load in specific muscles. The duration of experiments and characteristics of participants appear to be the factors that most have influenced the results. Future research should be focused on the improvement of the experimental protocols and instrumentation, in order to the outcomes represent adequately the actual working conditions. Relevance to industry: Introducing more physical workload variation in low-load repetitive work is considered an effective ergonomic intervention against muscle fatigue and musculoskeletal disorders in industry. Results will be useful to identify the need of future research, which will eventually lead to the adoption of best industrial work practices according to the workers capabilities.

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Tässä työssä tutkitaan ohjelmistoarkkitehtuurisuunnitteluominaisuuksien vaikutusta erään client-server –arkkitehtuuriin perustuvan mobiilipalvelusovelluksen suunnittelu- ja toteutusaikaan. Kyseinen tutkimus perustuu reaalielämän projektiin, jonka kvalitatiivinen analyysi paljasti arkkitehtuurikompponenttien välisten kytkentöjen merkittävästi vaikuttavan projektin työmäärään. Työn päätavoite oli kvantitatiivisesti tutkia yllä mainitun havainnon oikeellisuus. Tavoitteen saavuttamiseksi suunniteltiin ohjelmistoarkkitehtuurisuunnittelun mittaristo kuvaamaan kyseisen järjestelmän alijärjestelmien arkkitehtuuria ja luotiin kaksi suunniteltua mittaristoa käyttävää, työmäärää (komponentin suunnittelu-, toteutus- ja testausaikojen summa) arvioivaa mallia, joista toinen on lineaarinen ja toinen epälineaarinen. Näiden mallien kertoimet sovitettiin optimoimalla niiden arvot epälineaarista gloobaalioptimointimenetelmää, differentiaalievoluutioalgoritmia, käyttäen, niin että mallien antamat arvot vastasivat parhaiten mitattua työmäärää sekä kaikilla ominaisuuksilla eli attribuuteilla että vain osalla niistä (yksi jätettiin vuorotellen pois). Kun arkkitehtuurikompenttien väliset kytkennät jätettiin malleista pois, mitattujen ja arvoitujen työmäärien välinen ero (ilmaistuna virheenä) kasvoi eräässä tapauksessa 367 % entisestä tarkoittaen sitä, että näin muodostettu malli vastasi toteutusaikoja huonosti annetulla ainestolla. Tämä oli suurin havaitu virhe kaikkien poisjätettyjen ominaisuuksien kesken. Saadun tuloksen perusteella päätettiin, että kyseisen järjestelmän toteutusajat ovat vahvasti riippuvaisia kytkentöjen määrästä, ja näin ollen kytkentöjen määrä oli mitä todennäköisemmin kaikista tärkein työmäärään vaikuttava tekijä tutkitun järjestelmän arkkitehtuurisuunnittelussa.

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The use of the Bayes factor (BF) or likelihood ratio as a metric to assess the probative value of forensic traces is largely supported by operational standards and recommendations in different forensic disciplines. However, the progress towards more widespread consensus about foundational principles is still fragile as it raises new problems about which views differ. It is not uncommon e.g. to encounter scientists who feel the need to compute the probability distribution of a given expression of evidential value (i.e. a BF), or to place intervals or significance probabilities on such a quantity. The article here presents arguments to show that such views involve a misconception of principles and abuse of language. The conclusion of the discussion is that, in a given case at hand, forensic scientists ought to offer to a court of justice a given single value for the BF, rather than an expression based on a distribution over a range of values.

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La pratique du design industriel dans la province canadienne de l’Alberta est en pleine croissance. Ses activités sont principalement concentrées à Edmonton et à Calgary, qui sont les plus grandes villes de la province. On y trouve des studios de design de renom, des communautés de design complexes et des programmes universitaires de design bien établis. Cependant, la pratique du design industriel albertaine est sous-développée en comparaison avec celle du reste du Canada et il y a peu de recherches et de documentation sur le design industriel en Alberta. Dans ce projet de mémoire, la pratique du design industriel en Alberta a été explorée depuis une approche historique. Pour pallier le manque de documentation, la collecte de données a été faite par une recherche qualitative, des entretiens narratifs et une recherche quantitative statistique. Une base d’information historique sur le design industriel albertain a été établie puis située par rapport au développement de la pratique du design industriel ailleurs au Canada. Les facteurs, événements et tendances dans l’histoire de la pratique du design industriel en Alberta ont été identifiés. De plus, le développement de la pratique du design industriel de l’Alberta a été comparé à celui du Québec et de l’Ontario. Les retombées de cette étude indiquent que la pratique du design industriel en Alberta présente quatre domaines de spécialisations distincts se développant depuis les années 1980. La pratique du design industriel en Alberta est sous-développée en comparaison à celui du Québec et de l’Ontario, mais elle peut devenir plus compétitive, au niveau canadien, avec plus de soutien gouvernemental, de meilleures relations avec l’industrie manufacturière et les institutions académiques, une communauté de design plus unifiée et en portant une plus grande attention aux domaines les plus prometteurs de l’industrie. Ces informations supportent une meilleure compréhension de la pratique du design industriel en Alberta et pourront informer les praticiens, enseignants et administrateurs du domaine du design industriel dans la province. Finalement, le mémoire servira de base à d’autres projets de recherche sur les changements potentiels dans la pratique du design industriel en Alberta et l’étude du design canadien et des industries de design régionales.

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The distribution of endemic goitre in England and Wales was compared with the distribution of environmental iodine (atmospheric deposition, soil, surface water). Despite a very clear goitre belt through the west of England and Wales there was no patterning in the environmental iodine distribution. A clear seasonal variation in depositional iodine exists, with an unusually high concentration of iodine in March 1997. The temporal variation in iodine concentration is determined at the monthly and not the annual level. The presence of endemic goitre is no indicator of how iodine is distributed in the environment or vice versa!

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This paper follows the report on the “Quality of Urban Design: Study of the Influence of Private Property Decision Maker in Urban Design” (RICS 1996). It focuses on one of the findings in the report, namely that decisions made in development, investment and occupation seemed overly influenced by short term considerations. In this paper, the authors review the Report and examine the concept of short termism as it affects urban design decisions. The paper concludes that although it is difficult to establish whether or not short termism exists in many decisions, there are grounds for believing that a priori short termism might particularly influence property orientated decisions. The paper ends with some implications for policy both at the economy and local level.

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The determination of the amount of sample units that will compose the sample express the optimization of the workforce, and reduce errors inherent in the report of recommendation and evaluation of soil fertility. This study aimed to determine in three systems use and soil management, the numbers of units samples design, needed to form the composed sample, for evaluation of soil fertility. It was concluded that the number of sample units needed to compose the composed sample to determination the attributes of organic matter, pH, P, K, Ca, Mg, Al and H+Al and base saturation of soil vary by use and soil management and error acceptable to the mean estimate. For the same depth of collected, increasing the number of sample units, reduced the percentage error in estimating the average, allowing the recommendation of 14, 14 and 11 sample in management with native vegetation, pasture cultivation and corn, respectively, for a error 20% on the mean estimate.

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Is it really possible to create a (literary) text? It is actually impossible as to create an authentic text we need an authentic context which is impossible to create. So all the literary txets we have are not authentic and are not created authentically.

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