Kernel Estimation of Rate Function for Recurrent Event Data

Abstract.  Recurrent event data are largely characterized by the rate function but smoothing techniques for estimating the rate function have never been rigorously developed or studied in statistical literature. This paper considers the moment and least squares methods for estimating the rate function from recurrent event data. With an independent censoring assumption on the recurrent event process, we study statistical properties of the proposed estimators and propose bootstrap procedures for the bandwidth selection and for the approximation of confidence intervals in the estimation of the occurrence rate function. It is identified that the moment method without resmoothing via a smaller bandwidth will produce a curve with nicks occurring at the censoring times, whereas there is no such problem with the least squares method. Furthermore, the asymptotic variance of the least squares estimator is shown to be smaller under regularity conditions. However, in the implementation of the bootstrap procedures, the moment method is computationally more efficient than the least squares method because the former approach uses condensed bootstrap data. The performance of the proposed procedures is studied through Monte Carlo simulations and an epidemiological example on intravenous drug users.     

琉球诗散论

追溯中国古典诗歌载述和反映琉球的历史 ,重点论述明清中国诗人所写琉球诗发达的原因和主要内容 ,可以看出琉球诗具有浓厚的海洋气息和魅力 ,它拓展了中国古典诗歌的题材 ,在某种程度上也提高了诗人们的创作水平。琉球纪事诗不仅可与史籍相发明 ,而且有时可补史料的不足。     

从《朝天录》看朝鲜使节与域外文人的文化交流

李朝时期,朝鲜使臣频繁出使明朝,由于其另一身份为精通汉学的文人,因此与同样深受中国影响的域外文人进行了文学交流:李安讷同孔闻謤的诗歌酬唱,体现了中朝两国的文化认同;金尚宪与吴大斌的惺惺相惜,体现了文人间的友好情谊;李醉光与安南使者冯克宽、琉球使者蔡坚的文学往来,体现了朝鲜文学在安南等国的影响.朝鲜使臣在出使明朝的过程中,以文学为裁体,同域外文人进行了广泛的文化交流.     

飞灰冲蚀条件下材料抗磨性能的试验研究

本文首先综述了国内外学者在研究塑性材料耐冲蚀磨损性能方面所取得的主要成果,并在专门建立的灰磨试验台上,对电站燃煤锅炉对流受热面常用材料20号钢、12Cr_1MoV合金铜以及铜、铝四种塑性材料进行了耐飞灰冲蚀磨损性能的试验研究。提出用材料的体积磨损率来定义材料的耐冲蚀磨损性能系数。并用它表征塑性材料的抗磨性能。该系数可直接应用于计算燃煤锅炉对流受热面的安全烟速。     

铝基化学镀镍的研究

研究了铝基化学镀镍的工艺过程，详细介绍了化学镀镍前的处理过程，其中包括除油，浸蚀，清洗和没锌过程。研究了各因素对化学镀镍镀速的影响因素，并得出最佳配方及工艺条件。在最佳条件下，化学镀镍镀速高，镀层着附力优异，可焊性优良。     

论庭前证据交换制度

证据交换制度作为民事诉讼的一项重要制度有其自身的发展历程,从而显示了其重要的意义,并得到了各国的重视。我国也建立了民事诉讼证据交换制度,但仍存在着很多缺陷,所以有必要对我国的民事诉讼证据交换制度进行完善。     

黑龙江省工业资本产出贡献率的实证分析

提高老工业基地的经济增长水平,是一个意义深远的课题。黑龙江省老工业基地发展相对落后的原因在于工业实收资本结构的不合理,国家资本偏高,个人资本绝对性偏低,单位个人资本效率是单位国家资本的五倍。法人资本的多层代理也是造成黑龙江省工业发展相对落后的原因之一。对此,应妥善解决委托代理失灵问题,大力促进民营资本的发展,加快国有经济布局的战略性调整。     

《二十四孝图》新解

《二十四孝图》是中国封建历史上孝子的典范故事,作为华夏民族的优良传统体现出中国独特的人文精神,我们需要为此发扬光大。但需要用马克思历史唯物主义的观点来重新审视这种历史沉淀物,使其更好的体现民族品格。     

行政人的伦理困境和伦理自主

行政人与其他人一样生活在复杂的社会关系下并承担着不同的角色,每一种角色都附带着一系列的义务与利益规定。角色冲突、利益冲突甚至是道德冲突产生的伦理困境,使得行政人经常处于两难的境地。因此,应从创设制度化的个人伦理生存空间、行政人对角色责任的清醒认识、弘扬行政人的个体独立人格、界定行政人的忠诚限度等方面帮助行政人找到既可保存公共利益又可保存自己人格完整的有效途径。     

Towards Enhancement of the Economy of a Thermal Power Generating System through Prediction of Plant Efficiency

The plant ‘Heat Rate’ (HR) is a measure of overall efficiency of a thermal power generating system. It depends on a large number of factors, some of which are non-measurable, while data relating to others are seldom available and recorded. However, coal quality (expressed in terms of ‘effective heat value’ (EHV) as kcal/kg) transpires to be one of the important factors that influences HR values and data on EHV are available in any thermal power generating system. In the present work, we propose a prediction interval of the HR values on the basis of only EHV, keeping in mind that coal quality is one of the important (but not the only) factors that have a pronounced effect on the combustion process and hence on HR. The underlying theory borrows the idea of providing simultaneous confidence interval (SCI) to the coefficients of a p-th p(≥1) order autoregressive model (AR(p)). The theory has been substantiated with the help of real life data from a power utility (after suitable base and scale transformation of the data to maintain the confidentiality of the classified document). Scope for formulating strategies to enhance the economy of a thermal power generating system has also been explored.