Bounds on Parameters in Panel Dynamic Discrete Choice Models

Identification of dynamic nonlinear panel data models is an important and delicate problem in econometrics. In this paper we provide insights that shed light on the identification of parameters of some commonly used models. Using these insights, we are able to show through simple calculations that point identification often fails in these models. On the other hand, these calculations also suggest that the model restricts the parameter to lie in a region that is very small in many cases, and the failure of point identification may, therefore, be of little practical importance in those cases. Although the emphasis is on identification, our techniques are constructive in that they can easily form the basis for consistent estimates of the identified sets.     

Bounds in Competing Risks Models and the War on Cancer

In 1971, President Nixon declared war on cancer. Thirty years later, many declared this war a failure: the age‐adjusted mortality rate from cancer in 2000 was essentially the same as in the early 1970s. Meanwhile the age‐adjusted mortality rate from cardiovascular disease fell dramatically. Since the causes that underlie cancer and cardiovascular disease are likely dependent, the decline in mortality rates from cardiovascular disease may partially explain the lack of progress in cancer mortality. Because competing risks models (used to model mortality from multiple causes) are fundamentally unidentified, it is difficult to estimate cancer trends. We derive bounds for aspects of the underlying distributions without assuming that the underlying risks are independent. We then estimate changes in cancer and cardiovascular mortality since 1970. The bounds for the change in duration until death for either cause are fairly tight and suggest much larger improvements in cancer than previously estimated.     

一种基于PIM与核方法的模糊聚类新算法

本文针对模糊C均值聚类在大数据量时收敛较慢以及不能对多种数据结构有效聚类的缺点,结合PIM算法与核方法提出了一种新的高效聚类算法———KPIM算法,并从理论上证明了该算法的收敛性.最后利用标准实验数据IRIS数据集测试,结果表明KPIM算法在保证收敛速度的同时,聚类效果更有效.     

阁楼上的疯女人和森林里的巫婆--从疯女人的形象塑造看勃朗特的局限性和霍桑的先进性

本文对阁楼上的疯女人伯莎和出没于森林里的巫婆希宾斯夫人的形象以及勃朗特和霍桑在处理疯女人问题上的态度进行了比较分析,认为两位作家性别身份的不同以及时代背景的不同造成了勃朗特的局限性和霍桑的先进性。     

系统思维、可持续发展与法律的公平价值

系统科学的发展为人类重新考量世界、重新定位人与自然的关系奠定了自然科学基础。可持续发展观深刻揭示了社会-生态复合巨系统的运行机制,是系统思维的当代表征。在此时代背景下,法律的公平价值体现为代内公平与代际公平的统一     

关于弱化缓冲算子序列的研究

本文以预测过程中常常出现的冲击扰动问题为出发点,在灰色系统理论缓冲算子公理体系下,构造了一类弱化缓冲算子序列,对现有的弱化缓冲算子进行了整合,研究了这类弱化缓冲算子定义的内涵,实例验证了该算子序列的有效性和实用性,为解决冲击扰动系统在建模预测过程中出现的定量预测结果与定性分析结论不符的问题提供了可以借鉴的方法。     

经学同文学的分野与冲突--以唐宋与清代古文运动为例

本文以唐宋古文运动与清代桐城派的发展为切入点,描述了唐宋以来中国传统学术的文章之学、训诂之学、儒者之学由混沌一体而渐至分离的历史过程,以及在经学君临时代,古文一派为维护文章之学的独立地位与艺术品格所作出的不懈努力.     

高校思想政治教育进网络工作初探

更新观念、趋利避害、联合应对、积极诱导是网络时代高校思想政治教育工作必须把握的几个基本原则,在这个前提下,应努力探索高校思想政治教育进网络工作的有效途径,建立网上思想政治教育体系,把网络文化与校园文化结合起来,关注学生的网络心理和行为,加强对学生进行网络道德和法制教育。     

电站立式给水加热器传热强化及无铜化运行研究

针对电站立式给水加热器的传热特性和强度要求,研制并加工出小螺旋角内外螺旋翅片管（IOSF管）来强化其传热特性,基础试验表明,IOSF管的总传热系数比光滑管提高63%-95%;工业试验表明,采用IOSF管的立式高压加热器总换热系数提高43%,对钢螺旋槽管替代铜光滑管进行了实验研究,结果表明,钢质螺旋槽管给水加热器不仅能保证原有热负荷,还能提高其换热强度,实现了锅炉给水无钢化运行的要求。     

宿南地区构造控气作用

宿南地区是淮北地区重要的产煤地,亦是煤层气研究的重点区域,构造因素直接或间接控制着含煤地层形成乃至煤层气生产和聚集,由此出发,具体分析了宿南地区的断裂,褶皱构造的控气作用,指出在煤层埋深800-1200m的深度范围是煤层气勘探的有利地带。