Improving Convergence of the HastingsMetropolis Algorithm with an Adaptive Proposal

The HastingsMetropolis algorithm is a general MCMC method for sampling from a density known up to a constant. Geometric convergence of this algorithm has been proved under conditions relative to the instrumental (or proposal) distribution. We present an inhomogeneous HastingsMetropolis algorithm for which the proposal density approximates the target density, as the number of iterations increases. The proposal density at the n th step is a non-parametric estimate of the density of the algorithm, and uses an increasing number of i.i.d. copies of the Markov chain. The resulting algorithm converges (in n ) geometrically faster than a HastingsMetropolis algorithm with any fixed proposal distribution. The case of a strictly positive density with compact support is presented first, then an extension to more general densities is given. We conclude by proposing a practical way of implementation for the algorithm, and illustrate it over simulated examples.     

关于在高校试行会计委派制若干问题的思考

高校因经济管理方式和运行模式的转变 ,使得深化财务改革、规范财经秩序、确保国有资产的安全完整、扼制会计信息失真现象等成为当前的主要任务。会计委派制的实施有助于加强会计工作的监督和管理 ,起到从源头上控制的作用 ,因而在高校开展这项工作势在必行     

走出国有资产转让的三大认识误区

国有资产转让是国企改革的重要组成部分,其成败将直接影响、甚至决定国企改革的进程与结果。我们必须走出账面价值的认识误区,注重未来预期收益的“折现值”,走出资产流失的认识误区,注重资产流失与假资产流失之名行捣乱非流失资产转让之实的双重防范;走出否定国有资产转让的误区,充分意识因噎废食有可能拒一切转机于门外,而完善法规则可以亡羊补牢。     

网络环境下的学习模式探索

教育模式是教育观念、教育思想、教与学理论的集中体现,网络的出现为学习者提供了适应个性化需求的自主学习的机会,建立满足不同学生需要的网络学习模式,是网络教学的当务之急。     

福建省耕地流向及其与经济发展的关系

土地利用数量的净变化是土地双向变化的结果。在单一土地利用类型动态度模型基础上利用单一土地利用动态变化辅助方法:列表清单法和单一土地利用动态度双向模型,对福建省及各设区市耕地流向进行分析。并在此基础上,研究了福建省耕地的减少与经济发展的关系,提出福建省耕地保护的措施。     

高等职业教育呼唤创新理念

要谋求高等职业教育的永续发展,必须认真审视现阶段高等职业教育发展理念,致力于冲破传统学历教育的束缚,建立起终身教育的理念;从“唯知识”的教育质量观念向“以能力为本位”的教育理念转变;摒弃“单干”的教育模式,树立培养学生合作意识与合作能力的教育理念。高等职业教育理念的世界发展趋势符合我国情况,完善和改进高等职业教育理念,才能使我国的高等职业教育从深层次上切实地满足社会需求。     

对创建学习型编辑组织的思考

学习型编辑组织是编辑事业的发展趋势,文章对如何创建学习型编辑组织提出了4个思考点,分析了在创建期可能会遇到的困难并提出克服困难的对策。     

对《模拟电路》课程教学的思考和探索

《模拟电路》是电类学科的一门重要技术基础课程,本文针对《模电》课程的特点,根据自身讲授该课程的教学体会,进行了探索和尝试,并回顾和总结了提高《模电》课程课堂教学质量和教学效果的一些做法。     

Estimating rating transition probabilites with missing data

In this article we provide a rigorous treatment of one of the central statistical issues of credit risk management. GivenK-1 rating categories, the rating of a corporate bond over a certain horizon may either stay the same or change to one of the remainingK-2 categories; in addition, it is usually the case that the rating of some bonds is withdrawn during the time interval considered in the analysis. When estimating transition probabilities, we have thus to consider aK-th category, called withdrawal, which contains (partially) missing data. We show how maximum likelihood estimation can be performed in this setup; whereas in discrete time our solution gives rigorous support to a solution often used in applications, in continuous time the maximum likelihood estimator of the transition matrix computed by means of the EM algorithm represents a significant improvement over existing methods.     

转移价格在跨国公司中的作用及其限制——揭开跨国公司巧取豪夺的面纱

转移价格是跨国公司在母公司与子公司、子公司与子公司之间进行内部贸易所采用的价格 ,是人为调高或调低价格来转移利润而采取的重要手段 ,使子公司经营处于“亏损”状态 ,从而使东道国蒙受巨大经济损失。为此 ,各东道国为维护本国的合法权益而采取多种防范和监控措施来限制跨国公司用转移价格来实现其整体总利润额的增加。