排序方式: 共有34条查询结果,搜索用时 15 毫秒
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Samir Ranjit Jani Darryl Brown Zekarias Berhane Nadja Peter Renee Turchi 《Journal of American college health : J of ACH》2018,66(5):412-420
Objective: This study's purpose was to describe urban college students’ communication about hookah with health care providers. Participants: Participants included a random sample of undergraduate urban college students and health care providers. Methods: Students surveyed determined the epidemiology of hookah use in this population, how many health care providers asked about hookah, and how many students admitted hookah use to a physician. Results: Of 375 students surveyed, 78 (20.8%) had never tried it, 284 (75.7%) had smoked hookah at least once, and 64 students (22.6%) were classified as frequent hookah smokers. Only 15 (4.7%) reported a health care provider asking about hookah during visits, whereas 36 (12.7%) admitted their hookah use to a health care provider. Conclusion: Hookah use was found to be highly prevalent among students in one urban university. This study supports the hypothesis that few health care providers broach the topic with patients. Additional research on health consequences of hookah use, education, and improved screening is warranted. 相似文献
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Samir Moustafa Shaarawy 《统计学通讯:模拟与计算》2013,42(4):1481-1509
The main objective of this paper is to develop convenient Bayesian techniques for estimation and forecasting which can be used to analyze multiple (multivariate) autoregressive moving average processes. Based on the conditional likelihood function and the least squares estimates of the residuals, the marginal posterior distribution of the coefficients of the model is approximated by a matrix t distribution, the marginal posterior distribution of the precision matrix is approximated by a Wishart distribution, and the predictive distribution is approximated by a multivariate t distribution. Some numerical examples are given to demonstrate the idea of using the proposed techniques to analyze different types of multiple ARMA models. 相似文献
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An essential ingredient of any time series analysis is the estimation of the model parameters and the forecasting of future observations. This investigation takes a Bayesian approach to the analysis of time series by making inferences of the model parameters from the posterior distribution and forecasting from the predictive distribution. The foundation of the approach is to approximate the condi-tional likelihood by a normal-gamma distribution on the parameter space. The techniques illustrated with many examples of ARMA processes. 相似文献
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Food chain integrity demands strengthening the position of end consumers in the food system. Shaping this consumer-centric agenda leads to a multi-dimensional quest where actors in the food chain need to remodel their production, processing and disclosure norms by focusing on end consumers’ expectations. Food chain integrity so far has largely been explained using the angles of fraud and criminality to mainstream the criticality of curbing intentional contamination in food chain operations. However, the view which accounts for how food safety and food quality expand the understanding of food chain integrity remains underdeveloped. Addressing this concern, we conceptualize the interaction space between the notions of food chain integrity, food safety and food quality using a unifying lens of supply chain governance in the food chain. In doing so, we outline the safety and quality-oriented arcs of food chain governance that are instrumental in creating consumer-centric processes. Drawing from systematic reviews, a multi-disciplinary article set is constructed involving the scholarships of food sector management, logistics and supply chain management, marketing and general management. The key findings outline five principal themes to notionally characterize the targeted interaction space and set the foundation of consumer-centric supply chain governance for food chain integrity. Besides discussing diverse governance areas such as industrial co-regulation, newer emphasis areas for internal/external chain integration and the need for consumer integration in food chain processes, the thematic leads are distilled further to outline macro- and micro-level arcs of consumer-centric food chain governance along with strategic pathways for future research. 相似文献
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Compion Sara Meijs Lucas Cnaan Ram A. Krasnopolskaya Irina von Schnurbein Georg Abu-Rumman Samir 《Voluntas: International Journal of Voluntary and Nonprofit Organizations》2022,33(3):472-482
VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - In this article, we are concerned with the recruitment potential of one-off episodic events for attracting and retaining... 相似文献
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Usamah F. ALFARHAN Samir AL‐BUSAIDI 《International labour review / International Labour Office》2019,158(2):273-295
This article discusses earnings differentials among skilled Western, Arab and Asian migrants, who constitute most of the private sector labour force in Gulf Cooperation Council (GCC) countries, during the period 2012–14. Using two standard decomposition methodologies, it investigates the view that Westerners are paid premium rates due to the unobserved perceptions of private employers. The results indicate that while one‐third to three‐quarters of real hourly earnings differentials are attributable to differing observed levels of productivity‐related characteristics, the remainder are due to the incorporation of higher opportunity costs for Westerners into the bargaining process. The potential effect of unobserved perceptions is found to be irrelevant to observed earnings differentials. 相似文献
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Hedi Kortas Zouhaier Dhifaoui Samir Ben Ammou 《Statistical Methods and Applications》2012,21(3):251-277
In this paper, we investigate the use of wavelet techniques in the study of the nth order fractional Brownian motion (n-fBm). First, we exploit the continuous wavelet transform??s capabilities in derivative calculation to construct a two-step estimator of the scaling exponent of the n-fBm process. We show, via simulation, that the proposed method improves the estimation performance of the n-fBm signals contaminated by large-scale noise. Second, we analyze the statistical properties of the n-fBm process in the time-scale plan. We demonstrate that, for a convenient choice of the wavelet basis, the discrete wavelet detail coefficients of the n-fBm process are stationary at each resolution level whereas their variance exhibits a power-law behavior. Using the latter property, we discuss a weighted least squares regression based-estimator for this class of stochastic process. Experiments carried out on simulated and real-world datasets prove the relevance of the proposed method. 相似文献
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Samir K. Srivastava 《国际管理评论杂志》2007,9(1):53-80
There is a growing need for integrating environmentally sound choices into supply‐chain management research and practice. Perusal of the literature shows that a broad frame of reference for green supply‐chain management (GrSCM) is not adequately developed. Regulatory bodies that formulate regulations to meet societal and ecological concerns to facilitate growth of business and economy also suffer from its absence. A succinct classification to help academicians, researchers and practitioners in understanding integrated GrSCM from a wider perspective is needed. Further, sufficient literature is available to warrant such classification. This paper takes an integrated and fresh look into the area of GrSCM. The literature on GrSCM is covered exhaustively from its conceptualization, primarily taking a ‘reverse logistics angle’. Using the rich body of available literature, including earlier reviews that had relatively limited perspectives, the literature on GrSCM is classified on the basis of the problem context in supply chain's major influential areas. It is also classified on the basis of methodology and approach adopted. Various mathematical tools/techniques used in literature vis‐à‐vis the contexts of GrSCM are mapped. A timeline indicating relevant papers is also provided as a ready reference. Finally, the findings and interpretations are summarized, and the main research issues and opportunities are highlighted. 相似文献