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81.
钛合金电子束焊接接头疲劳试验数据统计分析   总被引:3,自引:0,他引:3  
本文利用国际焊接学会推荐的统计方法,对BT20钛合金电子束焊接接头焊态和焊后电子束局部热处理两种试样的疲劳试验结果进行了统计处理与分析.结果表明:对于BT20钛合金母材和电子束对接接头可以按铝合金参考FAT80级S—N曲线进行疲劳设计.建议在对BT20薄板进行电子束焊接和电子束局部热处理时应采取必要措施,以保证将焊接变形控制到最小程度,从而提高其疲劳强度.  相似文献   
82.
本文以外语类核心期刊《外语教学与研究》(外语类权威刊物)2006~2009年期各期各栏目发文数量为统计源,从栏目发文情况、各栏目作者区域分布情况和区域作者发文情况进行统计分析,以期获得相关数据,向作者和读者提供该核心期刊的发文现状信息,为他们今后的研究、撰写论文、投稿提供参考.  相似文献   
83.
Prime aim is to examine the way the culture sector reuses industrial buildings to instigate cultural activities in the municipalities. The discussion of various actors’ motivation for engagement is based on results from a case study, supplemented with findings from a coarse-meshed telephone survey. At national level overarching political guidelines can be traced back to white papers concerning cultural policy, urban transformation and cultural heritage, and the municipalities’ cultural policies mirror these guidelines. What tends to decide if such initiatives are considered successful are local abilities to cross sectorial divisions and instigate cooperation between municipal planners, private entrepreneurs and NGOs.  相似文献   
84.
There is still considerable uncertainty about how reproductive factors affect child mortality. This study, based on Demographic and Health Survey data from 28 countries in sub-Saharan Africa, shows that mortality is highest for firstborn children with very young mothers. Other children with young mothers, or of high birth order, also experience high mortality. Net of maternal age and birth order, a short preceding birth interval is associated with above average mortality. These patterns change, however, if time-invariant unobserved mother-level characteristics of importance for both mortality and fertility are controlled for in a multilevel–multiprocess model. Most importantly, there are smaller advantages associated with longer birth intervals and being older at first birth. The implications of alternative reproductive ‘strategies’ are discussed, taking into account that if the mother is older at birth, the child will also be born in a later calendar year, when mortality may be lower.  相似文献   
85.
This article examines three novels by Ukrainian realist Ivan Franko (1856–1916): Dlia domashn'oho ohnyshcha (For the Home Hearth, 1892), Osnovy suspil'nosti (Pillars of Society, 1894), and Perekhresni stezhky (Fateful Crossroads, 1900). Previous scholars saw elements of crime fiction in these works, but the actual relationship between the two genres of crime fiction and realism has not been fully developed. By studying the conventions of crime fiction, along with its antecedent, the Gothic, and their influence on Franko, the author shows the make-up of the early Ukrainian crime fiction genre and points to its importance in understanding Franko’s vacillation between realist and modernist tendencies. As she argues, the scales of his vacillation are tipped toward modernism in its decadent form, an existential void that characterized fin de siècle Europe. Hence, Franko’s “ideal” or programmatic realism (defined by Franko as a literary style with a didactic tendency aimed at educating society), which he introduced under the appealing cover of crime and Gothic motifs, ultimately failed him. The author proposes that it is the creative modes (Gothic and crime fiction) that Franko chose for voicing his ideas about social reforms that led him, unsuspectingly, away from his programmatic goal and toward the decadent aspects of modernism.  相似文献   
86.
In disease screening and diagnosis, often multiple markers are measured and combined to improve the accuracy of diagnosis. McIntosh and Pepe [Combining several screening tests: optimality of the risk score, Biometrics 58 (2002), pp. 657–664] showed that the risk score, defined as the probability of disease conditional on multiple markers, is the optimal function for classification based on the Neyman–Pearson lemma. They proposed a two-step procedure to approximate the risk score. However, the resulting receiver operating characteristic (ROC) curve is only defined in a subrange (L, h) of false-positive rates in (0,1) and the determination of the lower limit L needs extra prior information. In practice, most diagnostic tests are not perfect, and it is usually rare that a single marker is uniformly better than the other tests. Using simulation, I show that multivariate adaptive regression spline is a useful tool to approximate the risk score when combining multiple markers, especially when ROC curves from multiple tests cross. The resulting ROC is defined in the whole range of (0,1) and is easy to implement and has intuitive interpretation. The sample code of the application is shown in the appendix.  相似文献   
87.
Most studies of quality improvement deal with ordered categorical data from industrial experiments. Accounting for the ordering of such data plays an important role in effectively determining the optimal factor level of combination. This paper utilizes the correspondence analysis to develop a procedure to improve the ordered categorical response in a multifactor state system based on Taguchi's statistic. Users may find the proposed procedure in this paper to be attractive because we suggest a simple and also popular statistical tool for graphically identifying the really important factors and determining the levels to improve process quality. A case study for optimizing the polysilicon deposition process in a very large-scale integrated circuit is provided to demonstrate the effectiveness of the proposed procedure.  相似文献   
88.
An approach to the analysis of time-dependent ordinal quality score data from robust design experiments is developed and applied to an experiment from commercial horticultural research, using concepts of product robustness and longevity that are familiar to analysts in engineering research. A two-stage analysis is used to develop models describing the effects of a number of experimental treatments on the rate of post-sales product quality decline. The first stage uses a polynomial function on a transformed scale to approximate the quality decline for an individual experimental unit using derived coefficients and the second stage uses a joint mean and dispersion model to investigate the effects of the experimental treatments on these derived coefficients. The approach, developed specifically for an application in horticulture, is exemplified with data from a trial testing ornamental plants that are subjected to a range of treatments during production and home-life. The results of the analysis show how a number of control and noise factors affect the rate of post-production quality decline. Although the model is used to analyse quality data from a trial on ornamental plants, the approach developed is expected to be more generally applicable to a wide range of other complex production systems.  相似文献   
89.
In quantitative trait linkage studies using experimental crosses, the conventional normal location-shift model or other parameterizations may be unnecessarily restrictive. We generalize the mapping problem to a genuine nonparametric setup and provide a robust estimation procedure for the situation where the underlying phenotype distributions are completely unspecified. Classical Wilcoxon–Mann–Whitney statistics are employed for point and interval estimation of QTL positions and effects.  相似文献   
90.
The arrival in Portugal of recent migrants from the Indian subcontinent is normally a secondary movement from within Europe tied to the search for a regular pathway into legal integration in the EU. However, as favourable migration policy is not paired with easy economic integration onward migration is common. We argue that such complex migration strategies cannot be amply explored through an origin–destination model; instead we suggest that a translocal perspective provides a framework to examine connections and experiences of emplacement in places of passage/reception like Lisbon. Through a qualitative study of the migration journeys and emplaced practices of Punjabi migrants in Lisbon, our findings highlight relationality between multiple scales, elucidating how agency and structure interact at micro and macro levels in shaping migration experiences and outcomes. We show how the materiality of local community structures ensures the navigation of daily life in the city and provides pathways toward legality contributing to wider mobility regimes. Moreover, we illustrate how onward migration represents an individual strategy to realise different aspects of integration in other EU destinations challenging nation-state-bound understandings of citizenship/settlement and integration.  相似文献   
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