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71.
An individual-based model forDrosophila is formulated, based on competition amongst larvae consuming the same batch of food. The predictions of the model are supported by data for single speciesDrosophila populations reared in the laboratory. The model is used to build a simple discrete model for the dynamics ofDrosophila populations that are kept over a number of generations. The dynamics of a single species is shown to give either a stable equilibrium or fluctuations which can be periodic or chaotic. When the dynamics of a species in the absence of the other is periodic or chaotic, we found coexistence or two alternative states, on neither of which the species can coexist.  相似文献   
72.
智能型单总线温度控制器设计   总被引:1,自引:0,他引:1  
介绍了单总线数字式温度传感器(DS1820)的技术特性以及基于AT89C2051单片机温度控制应用系统的硬件电路设计和软件程序设计。  相似文献   
73.
高可用性系统的研究与实现   总被引:3,自引:0,他引:3  
研究了高可用系统的结构,介绍了一种高可用系统的实现。在分析系统失效因素和高可用系统结构的基础上,对主要的失效部分(软硬件)进行冗余以提高服务器、磁盘、网络可靠性,据此采用有效的失效探测与恢复机制,实现了一个能够保证整机容错,无单点失效的高可靠系统。  相似文献   
74.
The number of subjects in a pharmacokinetic two‐period two‐treatment crossover bioequivalence study is typically small, most often less than 60. The most common approach to testing for bioequivalence is the two one‐sided tests procedure. No explicit mathematical formula for the power function in the context of the two one‐sided tests procedure exists in the statistical literature, although the exact power based on Owen's special case of bivariate noncentral t‐distribution has been tabulated and graphed. Several approximations have previously been published for the probability of rejection in the two one‐sided tests procedure for crossover bioequivalence studies. These approximations and associated sample size formulas are reviewed in this article and compared for various parameter combinations with exact power formulas derived here, which are computed analytically as univariate integrals and which have been validated by Monte Carlo simulations. The exact formulas for power and sample size are shown to improve markedly in realistic parameter settings over the previous approximations. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
75.
赵霞  朱永亮 《河北学刊》2007,27(3):194-196
随着中国财政体制改革的不断深入,国库集中支付制度在全国范围内开始逐步推广实施,这项制度的推行对于中国的经济发展具有极其深远的意义。本文主要研究了进行国库集中支付制度改革的意义和所存在的问题,在此基础上提出了进一步完善国库集中支付制度的思路。  相似文献   
76.
Efforts to improve child survival in lower-income countries typically focus on fundamental factors such as economic resources and infrastructure provision, even though research from post-industrial countries confirms that family instability has important health consequences. We tested the association between maternal union instability and children’s mortality risk in Africa, Latin America and the Caribbean, and Asia using children’s actual experience of mortality (discrete-time probit hazard models) as well as their experience of untreated morbidity (probit regression). Children of divorced/separated mothers experience compromised survival chances, but children of mothers who have never been in a union generally do not. Among children of partnered women, those whose mothers have experienced prior union transitions have a higher mortality risk. Targeting children of mothers who have experienced union instability—regardless of current union status—may augment ongoing efforts to reduce childhood mortality, especially in Africa and Latin America where union transitions are common.  相似文献   
77.
In this paper, we derive some recurrence relations for the single and the product moments of order statistics from n independent and non-identically distributed Lomax and right-truncated Lomax random variables. These recurrence relations are simple in nature and could be used systematically in order to compute all the single and product moments of all order statistics in a simple recursive manner. The results for order statistics from the multiple-outlier model (with a slippage of p observations) are deduced as special cases. We then apply these results by examining the robustness of censored BLUE's to the presence of multiple outliers. Received: November 30, 1998; revised version: March 8, 2000  相似文献   
78.
There are increasing numbers of families in Australia headed by sole parents, but little is known about the experiences of those who also care for a child with a disability. Additional caring responsibilities have previously been shown to impact on the work participation of parents. This study involved qualitative analyses of interview data conducted with sole mothers with school‐aged children with disability (N = 11). Thematic analysis revealed four themes that enabled and supported participation in the workforce: social support; managing appointments; characteristics of the workplace; and the role of the school. Results suggest the importance of practical help from family and friends in facilitating participation in paid employment. Additionally, the importance of flexible appointment scheduling on the part of service providers was highlighted, as well as the importance of workplace flexibility and supportive workplace cultures. Such factors were important in supporting sole mothers to balance work with care, with important implications for personal and family wellbeing.  相似文献   
79.
This paper describes the findings of a survey of 1109 lesbians who attended the Women's Music Festival held in Michigan in carly August 1985. The primary objectives of the study were to document the incidence of domestic violence in a non-random sample of lesbian relationships; to identify and describe the types of domestic violence experienced and/or perpetrated; and to ascertain thc availability and accessibility of community helping resources to survivors and perpetrators after an abusive episode. Comparisons with domestic violence in heterosexual relationships are also made, followed by a discussion on the research and practice implications of the findings.  相似文献   
80.
No abstract available for this article.  相似文献   
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