990 resultados para Classes of Degeneracy


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Monotonicity with respect to all arguments is fundamental to the definition of aggregation functions, which are one of the basic tools in knowledge-based systems. The functions known as means (or averages) are idempotent and typically are monotone, however there are many important classes of means that are non-monotone. Weak monotonicity was recently proposed as a relaxation of the monotonicity condition for averaging functions. In this paper we discuss the concepts of directional and cone monotonicity, and monotonicity with respect to majority of inputs and coalitions of inputs. We establish the relations between various kinds of monotonicity, and illustrate it on various examples. We also provide a construction method for cone monotone functions.

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The work presented here characterise the engagement of one university library with two social media platforms popular with academic libraries. The collected data are analysed to identify the forms of Twitter and Facebook activity that engage library stakeholders in social media conversations. Associations were observed between: i) directed tweets from the library and mentions of the library by others on Twitter; and ii) comments from the library and comments from others on Facebook. Three broad classes of Twitter user interacting with the library were revealed: i) accounts strongly linked to the library with multiple to/from tweets; ii) those weakly linked to the library with, typically, a single tweet; and iii) those indirectly linked to the library through tweets mentioning the library and sent by other users. Two divergent forms of Facebook interaction with the library were highlighted: i) a library post generating a large sequence of comments, typically in response to a competition/challenge and ii) a library post with no comments, typically a photo post or a post inviting readers to click a link to find out more about an event/service. The work presented here is an initial investigation that provides useful insights, and offers a methodology for future research.

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Oral contraceptives (OCs), often referred to as "the pill", are the most commonly employed form of reversible contraception. OCs are comprised of combined synthetic estrogen and progestin, which work to suppress ovulation and subsequently protect against pregnancy. To date, almost 200 million women have taken various formulations of OC, making it one of the most widely consumed classes of medication in the world. While a substantial body of literature has been dedicated to understanding the physical effects of OCs, much less is known about the long term consequences of OC use on brain anatomy and the associated cognitive effects. Accumulating evidence suggests that sex hormones may significantly affect human cognition. This phenomenon has been commonly studied in older populations, such as in post-menopausal women, while research in healthy, pre-menopausal women remains limited. The current review focused on the effects of OCs on human cognition, with the majority of studies comparing pre-menopausal OC users to naturally cycling women. Human neuroimaging data and animal studies are also described herein. Taken together, the published findings on OC use and human cognition are varied. Of those that do report positive results, OC users appear to have improved verbal memory, associative learning and spatial attention. We recommend future research to employ blinding procedures and randomised designs. Further, more detailed information pertaining to the specific generation and phasic type of OCs, as well as menstrual cycle phase of the OC non-users should be considered to help unmask the potential impact of OC use on human cognition.

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Weak monotonicity was recently proposed as a relaxation of the monotonicity condition for averaging aggregation, and weakly monotone functions were shown to have desirable properties when averaging data corrupted with outliers or noise. We extended the study of weakly monotone averages by analyzing their ϕ-transforms, and we established weak monotonicity of several classes of averaging functions, in particular Gini means and mixture operators. Mixture operators with Gaussian weighting functions were shown to be weakly monotone for a broad range of their parameters. This study assists in identifying averaging functions suitable for data analysis and image processing tasks in the presence of outliers.

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Background: Previous research on alcohol mixed with energy drinks (AmED) has shown that use is typically driven by hedonistic, social, functional, and intoxication-related motives, with differential associations with alcohol-related harm across these constructs. There has been no research looking at whether there are subgroups of consumers based on patterns of motivations. Consequently, the aims were to determine the typology of motivations for AmED use among a community sample and to identify correlates of subgroup membership. In addition, we aimed to determine whether this structure of motivations applied to a university student sample. Methods: Data were used from an Australian community sample (n = 731) and an Australian university student sample (n = 594) who were identified as AmED consumers when completing an online survey about their alcohol and ED use. Participants reported their level of agreement with 14 motivations for AmED use; latent classes of AmED consumers were identified based on patterns of motivation endorsement using latent class analysis. Results: A 4-class model was selected using data from the community sample: (i) taste consumers (31%): endorsed pleasurable taste; (ii) energy-seeking consumers (24%): endorsed functional and taste motives; (iii) hedonistic consumers (33%): endorse pleasure and sensation-seeking motives, as well as functional and taste motives; and (iv) intoxication-related consumers (12%): endorsed motives related to feeling in control of intoxication, as well as hedonistic, functional, and taste motives. The consumer subgroups typically did not differ on demographics, other drug use, alcohol and ED use, and AmED risk taking. The patterns of motivations for the 4-class model were similar for the university student sample. Conclusions: This study indicated the existence of 4 subgroups of AmED consumers based on their patterns of motivations for AmED use consistently structured across the community and university student sample. These findings lend support to the growing conceptualization of AmED consumers as a heterogeneous group in regard to motivations for use, with a hierarchical and cumulative class order in regard to the number of types of motivation for AmED use. Prospective research may endeavor to link session-specific motives and outcomes, as it is apparent that primary consumption motives may be fluid between sessions.

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AIMS: Failure to complete high school predicts substantial economic and social disadvantage in adult life. The aim of this study was to determine the longitudinal association of mid-adolescent polydrug use and high school non-completion, relative to other drug use profiles. DESIGN: A longitudinal analysis of the relationship between polydrug use in three cohorts at grade 9 (age 14-15 years) and school non-completion (reported post-high school). SETTING: A State-representative sample of students across Victoria, Australia. PARTICIPANTS: A total of 2287 secondary school students from 152 high schools. The retention rate was 85%. MEASUREMENTS: The primary outcome was non-completion of grade 12 (assessed at age 19-23 years). At grade 9, predictors included 30-day use of eight drugs, school commitment, academic failure and peer drug use. Other controls included socio-economic status, family relationship quality, depressive symptoms, gender, age and cohort. FINDINGS: Three distinct classes of drug use were identified-no drug use (31.7%), mainly alcohol use (61.8%) and polydrug use (6.5%). Polydrug users were characterized by high rates of alcohol, tobacco and cannabis use. In the full model, mainly alcohol users and polydrug users were less likely to complete school than non-drug users [odds ratio (OR) = 1.54, 95% confidence interval (CI) = 1.17-2.03) and OR = 2.51, 95% CI = 1.45-4.33), respectively, P < 0.001]. These effects were independent of school commitment, academic failure, peer drug use and other controls. CONCLUSIONS: Mid-adolescent polydrug use in Australia predicts subsequent school non-completion after accounting for a range of potential confounding factors. Adolescents who mainly consume alcohol are also at elevated risk of school non-completion.

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Advanced high-strength steels (AHSS) are a class of steel used primarily in sheet form for automotive structures. The microstructures of the types of steel in this classification were initially multiphase, with ferrite as the dominant phase; however, grades introduced more recently have been fully martensitic or based on austenite. This chapter initially introduces the requirements of an automotive body structure, then the different classes of AHSS that have been used in the automotive industry and their typical characteristic tensile properties. The specific properties that are required for steel used in automotive body structures are subsequently described, including formability and crash behaviour. Finally, some of the current and future trends in the development of new steel grades are discussed.

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Data is becoming the world’s new natural resourceand big data use grows quickly. The trend of computingtechnology is that everything is merged into the Internet and‘big data’ are integrated to comprise completeinformation for collective intelligence. With the increasingsize of big data, refining big data themselves to reduce data sizewhile keeping critical data (or useful information) is a newapproach direction. In this paper, we provide a novel dataconsumption model, which separates the consumption of datafrom the raw data, and thus enable cloud computing for bigdata applications. We define a new Data-as-a-Product (DaaP)concept; a data product is a small sized summary of theoriginal data and can directly answer users’ queries. Thus, weseparate the mining of big data into two classes of processingmodules: the refine modules to change raw big data into smallsizeddata products, and application-oriented mining modulesto discover desired knowledge further for applications fromwell-defined data products. Our practices of mining big streamdata, including medical sensor stream data, streams of textdata and trajectory data, demonstrated the efficiency andprecision of our DaaP model for answering users’ queries

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After more than forty years studying growth, there are two classes of growth models that have emerged: exogenous and endogenous growth models. Since both try to mimic the same set of long-run stylized facts, they are observationally equivalent in some respects. Our goals in this paper are twofold First, we discuss the time-series properties of growth models in a way that is useful for assessing their fit to the data. Second, we investigate whether these two models successfully conforms to U.S. post-war data. We use cointegration techniques to estimate and test long-run capital elasticities, exogeneity tests to investigate the exogeneity status of TFP, and Granger-causality tests to examine temporal precedence of TFP with respect to infrastructure expenditures. The empirical evidence is robust in confirming the existence of a unity long-run capital elasticity. The analysis of TFP reveals that it is not weakly exogenous in the exogenous growth model Granger-causality test results show unequivocally that there is no evidence that TFP for both models precede infrastructure expenditures not being preceded by it. On the contrary, we find some evidence that infras- tructure investment precedes TFP. Our estimated impact of infrastructure on TFP lay rougbly in the interval (0.19, 0.27).

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Why don’t agents cooperate when they both stand to gain? This question ranks among the most fundamental in the social sciences. Explanations abound. Among the most compelling are various configurations of the prisoner’s dilemma (PD), or public goods problem. Payoffs in PD’s are specified in one of two ways: as primitive cardinal payoffs or as ordinal final utility. However, as final utility is objectively unobservable, only the primitive payoff games are ever observed. This paper explores mappings from primitive payoff to utility payoff games and demonstrates that though an observable game is a PD there are broad classes of utility functions for which there exists no associated utility PD. In particular we show that even small amounts of either altruism or enmity may disrupt the mapping from primitive payoff to utility PD. We then examine some implications of these results.

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Parametric term structure models have been successfully applied to innumerous problems in fixed income markets, including pricing, hedging, managing risk, as well as studying monetary policy implications. On their turn, dynamic term structure models, equipped with stronger economic structure, have been mainly adopted to price derivatives and explain empirical stylized facts. In this paper, we combine flavors of those two classes of models to test if no-arbitrage affects forecasting. We construct cross section (allowing arbitrages) and arbitrage-free versions of a parametric polynomial model to analyze how well they predict out-of-sample interest rates. Based on U.S. Treasury yield data, we find that no-arbitrage restrictions significantly improve forecasts. Arbitrage-free versions achieve overall smaller biases and Root Mean Square Errors for most maturities and forecasting horizons. Furthermore, a decomposition of forecasts into forward-rates and holding return premia indicates that the superior performance of no-arbitrage versions is due to a better identification of bond risk premium.

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This paper investigates which properties money-demand functions have to satisfy to be consistent with multidimensional extensions of Lucasí(2000) versions of the Sidrauski (1967) and the shopping-time models. We also investigate how such classes of models relate to each other regarding the rationalization of money demands. We conclude that money demand functions rationalizable by the shoppingtime model are always rationalizable by the Sidrauski model, but that the converse is not true. The log-log money demand with an interest-rate elasticity greater than or equal to one and the semi-log money demand are counterexamples.

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Vários trabalhos sugerem que os benefícios privados podem explicar o diferencial de preços entre espécies de ações com direitos diferenciados de voto. Entretanto, no Brasil o diferencial de preço entre a ação ordinária e a ação preferencial é negativo para várias empresas no período de julho de 1994 a setembro de 2002. Este trabalho investiga os determinantes que implicam este desconto da ação ordinária em relação à ação preferencial. Em particular, o trabalho analisa os impactos da liquidez, dos dividendos diferenciados, e das recentes mudanças na legislação sobre o prêmio pelo voto. Este artigo documenta que liquidez é extremamente relevante na determinação dos preços relativos. Constatações empíricas confirmam o impacto negativo da Lei n° 9.457 revogando os direitos dos ordinaristas minoritários de venda conjunta com controlador e o impacto positivo da introdução da Lei n° 10.303, restabelecendo estes direitos aos ordinaristas. Finalmente, a estrutura de propriedade se mostrou ter uma relação positiva com o prêmio pelo voto, mas a participação do maior acionista em ações ordinárias não apresentou uma relação significativa.

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Why don't agents cooperate when they both stand to gain? This question ranks among the most fundamental in the social sciences. Explanations abound. Among the most compelling are various configurations of the prisonerís dilemma (PD), or public goods problem. Payoffs in PDís are specified in one of two ways: as primitive cardinal payoffs or as ordinal final utility. However, as final utility is objectively unobservable, only the primitive payoff games are ever observed. This paper explores mappings from primitive payoff to utility payoff games and demonstrates that though an observable game is a PD there are broad classes of utility functions for which there exists no associated utility PD. In particular we show that even small amounts of either altruism or jealousy may disrupt the mapping from primitive payoff to utility PD. We then examine some implications of these results ñ including the possibility of conflict inducing growth.

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Five years ago, Coca-Cola Brasil launched a program named “Coletivo Project”, with the purpose to enjoy an opportunity of increase on the potential consumption power of the low-income pyramid population that lived on the “favelas”. At the same time, it had the objective to offer to them a social and financial impact, which is a trust on the future, the first job for the young adults’ participant of this program and an increase on their family source of revenues, through salaries. This was possible because through Coletivo Project, Coca-Cola identified the assets they have through its value chain, focusing on its competencies, such as retail, merchandising and logistics to apply them on courses to teach the young people of the communities and, as a result, form them to be able to find their new jobs. Internal indicators followed in a monthly basis by Coca-Cola demonstrated that the communities that had the presence of Coletivos, in comparison to those without Coletivos, had social and financial impacts. The social was the fact that the young formed started to have more confidence on their future and felt with a higher self-stem to apply for and obtain their first job. On the financial aspect, they were benefit through the increasing of their revenues and also their families and Coca-Cola had an increase on sales, when compared to a community without a Coletivo Project installed. This dissertation seeks to identify the current relationship between Coca-Cola and the communities, through the Coletivo Project classes performed on the NGOs located at this places, in order to identify opportunities for improvement the benefits and the impacts (financial and social) on the NGOs, communities and all stakeholders of this project. This dissertation examines this relationship, through presence interviews performed on four NGOs selected, and located on four of the twenty communities, that are participants of the Coletivo Project on Rio de Janeiro city. These interviews performed with the students, representatives and educators of these NGOs. The covered period of the interviews ranges from April 2014 to August 2014. This dissertation draws on first-hand qualitative empirical evidence gathered through extensive fieldwork. The main findings among possibilities for improvement by Coca-Cola are: • Implement new courses, beyond those existent at Coca-Cola (Retail, Logistics, etc.). • Increase the content of the employment module of Coletivo classes, focusing on improving educational, cultural, economic, political, social and professional life. • Increase the scale, through the quantity of positions on the Retail Coletivo classes. • Develop cultural and sports events with the communities. • Support the points of sales, participant of the practical classes of the Coletivo Retail, with refrigerators and furniture with the Coca-Cola logo. • Provide coffee breaks and meals during the Coletivo classes, using Coca-Cola beverages and partners for food items, developing the nutrition platform of the company and filling a need of the students. • Perform a research with all stakeholders related to this Project, including those students and mothers that are not participant of the Coletivo, in order to listen to them, understand their needs, and offer solutions to fulfill these gaps. and on the side of the • Perform partnerships with educational institutions to make viable other type of courses, more technical, but that have a relation with the core business of Coca-Cola Brasil, such as marketing. • Implement the Coca-Cola University, already existed at the Company. • Create courses or activities focused on the children. Regarding the impossibilities, the findings are: • Improve the basic sanitation of the communities. • Improve the safety on the communities. • Provide a home to those do not have. • Implement courses that have no relationship with Coca-Cola business and expertise, such as gastronomy. However, Coca-Cola can influence stakeholders on that. The results suggest to executives of Coca-Cola that a deep and a qualitative research on the communities of Brazil, in order to listen young people, educators, mothers, partners that offer jobs, from Coletivo and out of the project, is mandatory, to understand their needs, dreams, complains and offer valuable solutions to all.