777 resultados para inequalities
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Some new nonlinear integral inequalities that involve the maximum of the unknown scalar function of one variable are solved. The considered inequalities are generalizations of the classical nonlinear integral inequality of Bihari. The importance of these integral inequalities is defined by their wide applications in qualitative investigations of differential equations with "maxima" and it is illustrated by some direct applications.
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MSC 2010: 30A10, 30B10, 30B30, 30B50, 30D15, 33E12
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Снежана Христова, Кремена Стефанова, Лозанка Тренкова - В статията се изучават някои интегрални неравенства, които съдържат макси-мума на неизвестната функция на една променлива. Разглежданите неравенства са обобщения на класическото неравенство на Бихари. Значимостта на тези интегрални неравенства се дълже на широкото им приложение при качественото изследванене на различни свойства на решенията на диференциални уравнения с “максимум” и е илюстрирано с някои директни приложения.
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Кремена В. Стефанова - В тази статия са разрешени някои нелинейни интегрални неравенства, които включват максимума на неизвестната функция на две променливи. Разгледаните неравенства представляват обобщения на класическото неравенство на Гронуол-Белман. Значението на тези интегрални неравенства се определя от широките им приложения в качествените изследвания на частните диференциални уравнения с “максимуми” и е илюстрирано чрез някои директни приложения.
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2010 Mathematics Subject Classification: 26D10.
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2000 Mathematics Subject Classification: 60J45, 60K25
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MSC 2010: 30A10, 30C10, 30C80, 30D15, 41A17.
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2000 Mathematics Subject Classification: 26D10, 26D15.
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MSC 2010: 33E12, 30A10, 30D15, 30E15
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We consider a class of initial data sets (Σ,h,K) for the Einstein constraint equations which we define to be generalized Brill (GB) data. This class of data is simply connected, U(1)²-invariant, maximal, and four-dimensional with two asymptotic ends. We study the properties of GB data and in particular the topology of Σ. The GB initial data sets have applications in geometric inequalities in general relativity. We construct a mass functional M for GB initial data sets and we show:(i) the mass of any GB data is greater than or equals M, (ii) it is a non-negative functional for a broad subclass of GB data, (iii) it evaluates to the ADM mass of reduced t − φi symmetric data set, (iv) its critical points are stationary U(1)²-invariant vacuum solutions to the Einstein equations. Then we use this mass functional and prove two geometric inequalities: (1) a positive mass theorem for subclass of GB initial data which includes Myers-Perry black holes, (2) a class of local mass-angular momenta inequalities for U(1)²-invariant black holes. Finally, we construct a one-parameter family of initial data sets which we show can be seen as small deformations of the extreme Myers- Perry black hole which preserve the horizon geometry and angular momenta but have strictly greater energy.
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Objectives: To explore socioeconomic differences in four cardiovascular disease risk factors (overweight/obesity, smoking, hypertension, height) among manufacturing employees in the Republic of Ireland (ROI). Methods: Cross-sectional analysis of 850 manufacturing employees aged 18–64 years. Education and job position served as socioeconomic indicators. Group-specific differences in prevalence were assessed with the Chi-squared test. Multivariate regression models were explored if education and job position were independent predictors of the CVD risk factors. Cochran–Armitage test for trend was used to assess the presence of a social gradient. Results: A social gradient was found across educational levels for smoking and height. Employees with the highest education were less likely to smoke compared to the least educated employees (OR 0.2, [95% CI 0.1–0.4]; p b 0.001). Lower educational attainment was associated with a reduction in mean height. Non-linear differences were found in both educational level and job position for obesity/overweight. Managers were more than twice as likely to be overweight or obese relative to those employees in the lowest job position (OR 2.4 [95% CI 1.3–4.6]; p = 0.008). Conclusion: Socioeconomic inequalities in height, smoking and overweight/obesity were highlighted within a sub-section of the working population in ROI.
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This paper focuses on the ties between social and digital inequalities among Argentinean youth. It uses a qualitative approach to explore different aspects of the everyday lives of adolescents, such as sociability, leisure time and family use of Information and Communication Technologies (ICTs), in order to assess the impact of the Connecting Equality Program (Programa Conectar Igualdad, PCI) on reducing digital inequalities and fostering social inclusion. What were the existing conditions of access for students and their families when the PCI was first implemented? What influence does the implementation of the PCI have on the individual, family and scholastic appropriation of ICTs? How does the use of computers and the Internet vary among youth? Has this large-scale incorporation of netbooks in schools, and especially homes and free time changed it in any way? Does the appropriation of ICTs through student participation in the PCI contribute to material and symbolic social inclusion? In order to answer these questions, we compare the processes of ICT appropriation among lower and middle class adolescents, focusing on the distinctive uses and meanings assigned to computers and the Internet by boys and girls in their daily lives. For this purpose we analyze data collected through semi-structured interviews in two schools in Greater La Plata, Argentina during 2012. The main findings show that in terms of access, skills and types of use, the implementation of the PCI has had a positive impact among lower class youth, guaranteeing access to their first computers and promoting the sharing of knowledge and digital skills with family members. Moreover, evidence of more diverse and intense use of ICTs among lower class students reveals the development of digital skills related to educational activities. Finally, in terms of sociability, having a personal netbook enables access to information and cultural goods which are very significant in generating ties and strengthening identities and social integration
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This paper focuses on the ties between social and digital inequalities among Argentinean youth. It uses a qualitative approach to explore different aspects of the everyday lives of adolescents, such as sociability, leisure time and family use of Information and Communication Technologies (ICTs), in order to assess the impact of the Connecting Equality Program (Programa Conectar Igualdad, PCI) on reducing digital inequalities and fostering social inclusion. What were the existing conditions of access for students and their families when the PCI was first implemented? What influence does the implementation of the PCI have on the individual, family and scholastic appropriation of ICTs? How does the use of computers and the Internet vary among youth? Has this large-scale incorporation of netbooks in schools, and especially homes and free time changed it in any way? Does the appropriation of ICTs through student participation in the PCI contribute to material and symbolic social inclusion? In order to answer these questions, we compare the processes of ICT appropriation among lower and middle class adolescents, focusing on the distinctive uses and meanings assigned to computers and the Internet by boys and girls in their daily lives. For this purpose we analyze data collected through semi-structured interviews in two schools in Greater La Plata, Argentina during 2012. The main findings show that in terms of access, skills and types of use, the implementation of the PCI has had a positive impact among lower class youth, guaranteeing access to their first computers and promoting the sharing of knowledge and digital skills with family members. Moreover, evidence of more diverse and intense use of ICTs among lower class students reveals the development of digital skills related to educational activities. Finally, in terms of sociability, having a personal netbook enables access to information and cultural goods which are very significant in generating ties and strengthening identities and social integration
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This paper focuses on the ties between social and digital inequalities among Argentinean youth. It uses a qualitative approach to explore different aspects of the everyday lives of adolescents, such as sociability, leisure time and family use of Information and Communication Technologies (ICTs), in order to assess the impact of the Connecting Equality Program (Programa Conectar Igualdad, PCI) on reducing digital inequalities and fostering social inclusion. What were the existing conditions of access for students and their families when the PCI was first implemented? What influence does the implementation of the PCI have on the individual, family and scholastic appropriation of ICTs? How does the use of computers and the Internet vary among youth? Has this large-scale incorporation of netbooks in schools, and especially homes and free time changed it in any way? Does the appropriation of ICTs through student participation in the PCI contribute to material and symbolic social inclusion? In order to answer these questions, we compare the processes of ICT appropriation among lower and middle class adolescents, focusing on the distinctive uses and meanings assigned to computers and the Internet by boys and girls in their daily lives. For this purpose we analyze data collected through semi-structured interviews in two schools in Greater La Plata, Argentina during 2012. The main findings show that in terms of access, skills and types of use, the implementation of the PCI has had a positive impact among lower class youth, guaranteeing access to their first computers and promoting the sharing of knowledge and digital skills with family members. Moreover, evidence of more diverse and intense use of ICTs among lower class students reveals the development of digital skills related to educational activities. Finally, in terms of sociability, having a personal netbook enables access to information and cultural goods which are very significant in generating ties and strengthening identities and social integration
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There is a growing literature which documents the importance of early life environment for outcomes across the life cycle. Research, including studies based on Irish data, demonstrates that those who experience better childhood conditions go on to be wealthier and healthier adults. Therefore, inequalities at birth and in childhood shape inequality in wellbeing in later life, and the historical evolution of the mortality and morbidity of children born in Ireland is important for understanding the current status of the Irish population. In this paper, I describe these patterns by reviewing the existing literature on infant health in Ireland over the course of the 20th century. Up to the 1950s, infant mortality in Ireland (both North and South) was substantially higher than in other developed countries, with a large penalty for those born in urban areas. The subsequent reduction in this penalty, and the sustained decline in infant death rates, occurred later than would be expected from the experience in other contexts. Using records from the Rotunda Lying-in Hospital in Dublin, I discuss sources of disparities in stillbirth in the early 1900s. Despite impressive improvements in death rates since that time, a comparison with those born at the end of the century reveals that Irish children continue to be born unequal. Evidence from studies which track people across the life course, for example research on the returns to birthweight, suggests that the economic cost of this early life inequality is substantial.