Multiple event times in the presence of informative censoring: modeling and analysis by copulas

Motivated by a breast cancer research program, this paper is concerned with the joint survivor function of multiple event times when their observations are subject to informative censoring caused by a terminating event. We formulate the correlation of the multiple event times together with the time to the terminating event by an Archimedean copula to account for the informative censoring. Adapting the widely used two-stage procedure under a copula model, we propose an easy-to-implement pseudo-likelihood based procedure for estimating the model parameters. The approach yields a new estimator for the marginal distribution of a single event time with semicompeting-risks data. We conduct both asymptotics and simulation studies to examine the proposed approach in consistency, efficiency, and robustness. Data from the breast cancer program are employed to illustrate this research.

     

External knowledge search,absorptive capacity and radical innovation in high-technology firms

Open innovation and absorptive capacity are two concepts based on the idea that companies can leverage the knowledge generated externally to improve their innovation performance. The aim of this paper is to analyse the joint effect of open innovation and absorptive capacity on a firm's radical innovation. Open innovation is expressed in terms of external search breadth and depth strategies and absorptive capacity is described by distinguishing between potential and realized absorptive capacity. In order to test our hypotheses, we carried out empirical research in firms operating in high-technology industries. The results indicate that internal routines and processes for absorbing external knowledge help explain radical innovation as they show a significant effect of potential and realized absorptive capacity. Also, there is a moderating effect of absorptive capacity on open innovation. Specifically, potential absorptive capacity exerts a positive effect on the relationship between external search breadth and depth and radical innovation. Realized absorptive capacity moderates the influence of external search breadth. These findings confirm the complementary nature of absorptive capacity and open innovation search strategies on radical innovation.     

Tests for time series of counts based on the probability-generating function

We propose testing procedures for the hypothesis that a given set of discrete observations may be formulated as a particular time series of counts with a specific conditional law. The new test statistics incorporate the empirical probability-generating function computed from the observations. Special emphasis is given to the popular models of integer autoregression and Poisson autoregression. The asymptotic properties of the proposed test statistics are studied under the null hypothesis as well as under alternatives. A Monte Carlo power study on bootstrap versions of the new methods is included as well as real-data examples.     

Adolescent Protective Factors Promoting Resilience in Young Adults at Risk for Depression

In a longitudinal, community-based study, adolescent protective factors for those at risk for depression were identified that were associated with resilient outcomes in young adulthood. For those with childhood risk factors for major depression, significant protective factors included family cohesion, positive self appraisals, and good interpersonal relations. Findings may help inform the development of prevention and treatment programs for adolescents vulnerable to depression. Implications for future research and clinical practice are discussed.     

腔内电光调制激光系统的混沌模拟

采用数值模拟的方法讨论了带反馈的腔內电光调制激光系统功率输出的分叉和混沌行为,得到了输出功率随控制参数变化的分叉图,和一些定量结果。     

张之洞实业教育观之我见

实业教育观是张之洞教育思想的重要组成部分 ,它是张之洞与外洋抗争思想的直接结果之一。它以创办实业学堂、派遣留学生及倡导理论与实践相结合的教学方法为主旨 ;以培养近代农、工、商业人才 ,推动经济发展为目的 ,在中国近代历史上影响较为深远。     

充分利用土地资源推进县域经济发展

土地资源是人类一切活动的载体,是发展县域经济的基石,是推进县域经济发展的动力.发展县域经济既是贯彻十六大精神的战略要求,又是县域经济发展的客观需求,更是全面建设小康社会的重要举措.因此,必须紧紧抓住充分利用土地资源这个纲,才能有效地推进县域经济尽快进入高速发展的快车道.怎样充分利用土地资源,发展县域经济,本文提出几点探讨性意见.     

德国功能派翻译理论述评

功能派翻译理论是20世纪70年代德国学者提出的翻译理论.主要理论有赖斯的文本类型和语言功能理论,曼塔利的翻译行为理论,威密尔的目的论和诺德的功能加忠诚理论,其核心是翻译目的或译文功能.该理论体系以目的为总则,把翻译放在行为理论和跨文化交际理论的框架中,为西方翻译理论界开辟了一条新的研究道路,它对中国译学的理论研究具有很高的参考和借鉴价值.     

网络技术与民族文化的创新

网络技术的产生和应用对民族文化的发展既是机遇又是挑战,创新才是民族文化把握机遇和应对挑战的惟一途径。创新民族文化首先要继承优秀的传统文化,祛除其糟粕。创新民族文化还要随时代的发展不断创造新的民族文化的内容和形式。创新民族文化更要让民族文化参与全球化进程,让世界了解和认同本民族文化,同时也要引进外来文化来促进民族文化的发展。