Simulation-based sequential Bayesian design

We consider simulation-based methods for exploration and maximization of expected utility in sequential decision problems. We consider problems which require backward induction with analytically intractable expected utility integrals at each stage. We propose to use forward simulation to approximate the integral expressions, and a reduction of the allowable action space to avoid problems related to an increasing number of possible trajectories in the backward induction. The artificially reduced action space allows strategies to depend on the full history of earlier observations and decisions only indirectly through a low dimensional summary statistic. The proposed rule provides a finite-dimensional approximation to the unrestricted infinite-dimensional optimal decision rule. We illustrate the proposed approach with an application to an optimal stopping problem in a clinical trial.     

更行更远更生——论90年代女性文学中性别意识的强化与超越

90年代的女性文学 ,避开了性别政治简单分裂的危险 ,融敏锐的性别体悟与宽厚的人间情怀于一体 ,从跨性别外视点与女性内观点“联网”的角度进行自我审视、世俗关怀及对于历史、文化的多重思考和全息化的把握     

二语习得中的动词形态多选现象研究

在最简方案框架内讨论了L2英语动词形态的多选问题。在L2语法发展阶段,多选现象是多个侯选词项参与竞选同一个句法节点位置插入的结果;不同的词项在不同的语境中获胜。动词形态标注不但与句法节点上的相关特征习得有关,还与词汇示例的特征标注习得有关。如果学习者仅仅习得句法位置上的相关特征,而没有完全习得相关词汇示例的特征标注,多选现象仍可发生。过多的语境和特征标注数目增加了动词形态标注的难度,因此,在动词形态的句法特征被习得以后,多选现象仍有可能继续出现。在L2语法达到稳定阶段之后,如果习得者的内部语法对某一个特定动词形态标注有"石化"现象,那么多选现象有可能永远持续下去。     

Riemann-Lebesgue引理

对Ｌｅｂｅｓｇｕｅ可积函数空间中的Ｒｉｅｍａｎｎ－Ｌｅｂｅｓｇｕｅ引理及其推广形式进行了讨论，证明和推广了一些结果     

LF闭包空间的紧性是L—好的推广

在LF闭包空间中，引入分明紧空间、诱导LF闭包空间和LF紧空间等概念。证明了LF闭包空间的紧性是L－好的推广。     

从槐米中提取芦丁的酸化条件研究

碱溶酸沉法是提取芦丁的常规方法，但对其酸沉时的酸度的确定，文献报导多有不同。在大量实验的基础上，优化出最佳酸化条件为pH3.5左右，且使其提取收率比原来提高了0.6％。     

论资产负债观在新会计准则中的运用与思考——历史演进、表征与思考

资产负债观与收入费用观不仅是两种不同的损益计价的观点,更是对会计准则的制定产生不同经济后果的会计理念。本文通过对资产负债观与收入费用观的内涵辨析和历史演进的分析,联系新准则中资产负债观的运用表征,并最终得到资产负债观与收入费用观的运用是以外部环境作为逻辑起点的结论。因此,我国准则制定中不是简单否定其中哪一个,而是适时、适境的做到两者的平衡。     

医疗纠纷的法律适用

随着公民法制观念和自我保护的法律意识不断增强 ,医疗纠纷案件大量增加 ,但现行的《医疗事故处理办法》已不能适应形势的发展。本文对医疗事故的认定是由医疗事故鉴定委员会的鉴定结论为最终结论 ,实际上是让一方当事人的上级主管部门作为鉴定人来作鉴定结论 ,使人身伤害的侵权者没有得到相应的民事责任追究 ,受害人得不到应有的民事赔偿 ,这有悖于民法通则中公平、平等的原则 ,并提出相应的解决办法。文章还对医疗纠纷的法律适用和赔偿原则作有益探讨     

Statistical precision of DEA and Malmquist indices: A bootstrap application to Norwegian grain producers

Previous applications of data envelopment analysis (DEA) and its subsequent Malmquist indices to efficiency and productivity measurements have been criticised for not providing statistical inferences regarding the significance of observed results. In this paper, DEA and a Malmquist index are combined with a bootstrap method in order to provide succinct statistical inferences that determine the performance of grain producers in Eastern Norway. The data cover the period between 1987 and 1997. Results reveal: (i) a significant degree of inefficiency (approximately 11%) and an average productivity progress of 38% over the period considered; (ii) the formidable productivity progress observed is primarily explained by technical efficiency changes that enabled producers to catch up with front runners; and (iii) environmental factors, such as weather conditions, impact both efficiency and productivity. Finally, the analysis reveals that using bootstrapping to make statistical inferences suggests that researchers should be careful in making performance comparisons based on conventional DEA methods, as any discovered differences may not be significant.     

分析维果茨基的智慧发展思想

智慧是人类有别于其他动物 ,被称之为高级动物的根本标志。人类智慧是怎样产生和发展的 ,心理学家们的观点不一 ,其中维果茨基的智慧发展思想独树一帜。他从文化———历史的视角分析和解释智慧的形成和发展 ,给智慧理论乃至整个心理发展理论领域注入了新的血液。他用意识、活动、内化、言语、合作等概念恰如其分地描述智慧形成的结构及其智慧发展的过程 ,是值得进一步挖掘和推广的理论思想