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排序方式: 共有947条查询结果,搜索用时 15 毫秒
1.
It is uncertain whether Latin America and Caribbean (LAC) countries are approaching a single mortality regime. Over the last three decades, LAC has experienced major public health interventions and the highest number of homicides in the world. However, these interventions and homicide rates are not evenly shared across countries. This study documents trends in life expectancy and lifespan variability for 20 LAC countries, 2000–14. By extending a previous method, we decompose differences in lifespan variability between LAC and a developed world benchmark into cause-specific effects. For both sexes, dispersion of amenable diseases through the age span makes the largest contribution to the gap between LAC and the benchmark. Additionally, for males, the concentration of homicides, accidents, and suicides in mid-life further impedes mortality convergence. Great disparity exists in the region: while some countries are rapidly approaching the developed regime, others remain far behind and suffer a clear disadvantage in population health. 相似文献
2.
Computing maximum likelihood estimates from type II doubly censored exponential data 总被引:1,自引:0,他引:1
Arturo J. fernández José I. Bravo Íñigo De Fuentes 《Statistical Methods and Applications》2002,11(2):187-200
It is well-known that, under Type II double censoring, the maximum likelihood (ML) estimators of the location and scale parameters, θ and δ, of a twoparameter exponential distribution are linear functions
of the order statistics. In contrast, when θ is known, theML estimator of δ does not admit a closed form expression. It is shown, however, that theML estimator of the scale parameter exists and is unique. Moreover, it has good large-sample properties. In addition, sharp
lower and upper bounds for this estimator are provided, which can serve as starting points for iterative interpolation methods
such as regula falsi. Explicit expressions for the expected Fisher information and Cramér-Rao lower bound are also derived.
In the Bayesian context, assuming an inverted gamma prior on δ, the uniqueness, boundedness and asymptotics of the highest
posterior density estimator of δ can be deduced in a similar way. Finally, an illustrative example is included. 相似文献
3.
Andrée Coulombe M.Ps. Robert Ladouceur Ph.D. Raymond Desharnais Ph.D. Jean Jobin Ph.D. 《Journal of gambling studies / co-sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming》1992,8(3):235-244
This study investigated the relationship between the level of arousal (Heart Rate) and the number of erroneous perceptions among video poker players. Twelve regular and twelve occasional gamblers participated in a gambling session conducted in a natural environment. It was hypothesised that 1) a significant positive correlation would be observed between arousal and the number of erroneous verbalizations, 2) regular players would show a higher level of arousal than occasional players, and 3) they would emit more erroneous verbalizations. Results showed that hypotheses one and three were confirmed. Theoretical and practical implications of these results for the psychology of gambling are discussed.This study was supported by a grant from Loto-Québec. 相似文献
4.
In this paper we develop a study on several types of parallel genetic algorithms (PGAs). Our motivation is to bring some uniformity to the proposal, comparison, and knowledge exchange among the traditionally opposite kinds of serial and parallel GAs. We comparatively analyze the properties of steady-state, generational, and cellular genetic algorithms. Afterwards, this study is extended to consider a distributed model consisting in a ring of GA islands. The analyzed features are the time complexity, selection pressure, schema processing rates, efficacy in finding an optimum, efficiency, speedup, and resistance to scalability. Besides that, we briefly discuss how the migration policy affects the search. Also, some of the search properties of cellular GAs are investigated. The selected benchmark is a representative subset of problems containing real world difficulties. We often conclude that parallel GAs are numerically better and faster than equivalent sequential GAs. Our aim is to shed some light on the advantages and drawbacks of various sequential and parallel GAs to help researchers using them in the very diverse application fields of the evolutionary computation. 相似文献
5.
Recently, we developed a GIS-Integrated Integral Risk Index (IRI) to assess human health risks in areas with presence of environmental pollutants. Contaminants were previously ranked by applying a self-organizing map (SOM) to their characteristics of persistence, bioaccumulation, and toxicity in order to obtain the Hazard Index (HI). In the present study, the original IRI was substantially improved by allowing the entrance of probabilistic data. A neuroprobabilistic HI was developed by combining SOM and Monte Carlo analysis. In general terms, the deterministic and probabilistic HIs followed a similar pattern: polychlorinated biphenyls (PCBs) and light polycyclic aromatic hydrocarbons (PAHs) were the pollutants showing the highest and lowest values of HI, respectively. However, the bioaccumulation value of heavy metals notably increased after considering a probability density function to explain the bioaccumulation factor. To check its applicability, a case study was investigated. The probabilistic integral risk was calculated in the chemical/petrochemical industrial area of Tarragona (Catalonia, Spain), where an environmental program has been carried out since 2002. The risk change between 2002 and 2005 was evaluated on the basis of probabilistic data of the levels of various pollutants in soils. The results indicated that the risk of the chemicals under study did not follow a homogeneous tendency. However, the current levels of pollution do not mean a relevant source of health risks for the local population. Moreover, the neuroprobabilistic HI seems to be an adequate tool to be taken into account in risk assessment processes. 相似文献
6.
Current developments in the sociotechnical framework address a number of vital issues that failed to occupy the high ground in its formative years. These include: (i) the purpose of the systems, to create customer value under social and resource constraints, (ii) the context or external business environment, and (iii) the dynamics of the sociotechnical system. Due attention to the dominant issues of purpose, context, and their dynamics make it more meaningful to speak of sociotechnical business systems (STBS) and organizational learning instead of sociotechnical systems (STS) and individual learning. In STBS each unit in an organization has business responsibilities and goal-based couplings with its environment and focuses on the creation of customer value. The implications of this shift from STS to STBS are discussed and illustrated with current research and two summary case studies. 相似文献
7.
Patients' views of patient-physician interactions—particularly the perspectives of older, ethnically diverse women—are poorly understood. The older patient's attitude toward and understanding of the medical encounter, however, are essential to the design of strategies to improve patient-physician communication. To date, investigations have primarily emphasised the ways in which the therapeutic relationship is influenced by immutable patient characteristics. This qualitative study extends previous research findings by looking beyond the effect of ascribed categories (such as age, race, and gender) and focusing on aspects of patient behavior, specifically assertiveness. Focus groups were conducted with older African-, Chinese-, European-, and Hispanic American breast cancer patients from sites in the eastern and western United States. The study explores the potential of a form of patient activation for challenging stereotypes of the elderly and changing health care practitioners' behavior. 相似文献
8.
A cooperative game with transferable utilities– or simply a TU-game – describes a situation in which players can obtain certain payoffs by cooperation. A solution concept for these games is a function which assigns to every such a game a distribution of payoffs over the players in the game.
Famous solution concepts for TU-games are the Shapley value and the Banzhaf value. Both solution concepts have been axiomatized in various ways.
An important difference between these two solution concepts is the fact that the Shapley value always distributes the payoff
that can be obtained by the `grand coalition' consisting of all players cooperating together while the Banzhaf value does
not satisfy this property, i.e., the Banzhaf value is not efficient. In this paper we consider the normalized Banzhaf value which distributes the payoff that can be obtained by the `grand coalition' proportional to the Banzhaf values of the players.
This value does not satisfy certain axioms underlying the Banzhaf value. In this paper we introduce some new axioms that characterize
the normalized Banzhaf value. We also provide an axiomatization of the Shapley value using similar axioms.
Received: 10 April 1996 / Accepted: 2 June 1997 相似文献
9.
Serious mental health problems exist within the Chinese population of the United States. This article describes one center's attempt to meet the psychiatric needs of both nonpsychotic and psychotic Chinese patients through bilingual, culturally relevant treatments. 相似文献
10.
Burge E Kuhne N Berchtold A Maupetit C von Gunten A 《European review of aging and physical activity》2012,9(1):27-39
The objectives of this study were to describe the different modalities of physical activity programs designed for moderate
to severe dementia and to identify their impact on functional independence in activities of daily living (ADL). A critical
review of randomized controlled trials related to the impact of physical activity programs in moderately to severely demented
persons on ADL performance and meta-analysis of the identified studies were performed. Among the 303 identified articles,
five responded to the selection criteria. Four out of the five studies demonstrated limited methodological quality. In one
high-quality study, physical activity programs significantly delayed deterioration of ADL performance. The program components
and ADL assessment tools vary widely across studies. Although the proposed treatments have not proven their efficiency in
improving the ADL status of the patients, they were able to limit the decline in ADL functioning. Future research is warranted
in order to identify clinically relevant modalities for physical activity programs for people with moderate to severe dementia. 相似文献