拟象与隐喻

本文试图从认知隐喻理论,尤其是交织模式的角度解释隐喻与拟象两概念之间的内在关系.依靠相似来连接两事物是人类心智活动的基本方式之一.将隐喻与拟象看作互动关系有助于完整连贯地解释各种语言现象.     

用时域信息改善机扫雷达参数估计性能的方法

针对一个波束宽度内存在多目标的情况,提出了一种基于时空级联处理的用单天线、单接收通道实现目标角度和多普勒频率联合超分辨估计的方法.与阵列天线利用目标反射波的相位关系不同,单天线、单通道方法是根据天线扫描时,对回波脉冲的增益变化而构造导向矢量阵的,此时若直接采用常规空间谱估计方法,则实现的是信号多普勒频率的超分辨,角度估计效果较差.时空级联处理方法可充分利用信号的时域结构信息,明显提高角度的估计性能,并且无需高维搜索,计算量小.计算机仿真结果证明了新算法的有效性和正确性.     

象似性理论与汉语语法教学

汉语语法教学引入语法象似性理论,有助于解决汉语语法教学所面临的基本问题—投入大,产出少,效益低。它不仅化抽象为具体,而且联系学生已有的知识,更容易达到教学目的。引入的基本途径为：引入距离象似性,解决语言单位相互间距离的远近问题;引入数量象似性,解决语言单位数量与信息量的关系问题;引入顺序象似性,解决语言单位的排列顺序问题,等等。     

论语言符号的内在象似性

国内外研究表明,不同的语言之间均在一定程度上存在语音、语义、功能等形式上的象似性。语言符号具有内在象似性,是不同语种群体之间交际活动得以进行的条件。从语言的起源及其演化来看,语言符号的内在象似性不仅客观存在,而且是语言竞争演化的趋势,其根本决定因素在于语言是人类认知的产物,人类认知的共性决定了语言符号的内在象似性。     

语篇象似性与翻译

象似性存在于语言的各个层面上。在篇章中的象似性现象有重要的表意功能。因此,翻译不仅仅是语言符号之间的转换,同时也要受篇章象似性的制约。文章主要从距离象似性,语音象似性,形状象似性和对称象似性来讨论篇章象似性对翻译的制约。     

词序像似性研究及实例分析

像似性是相对任意性而言的。语言像似性是指语言形式或结构与其所表达的概念之间存在对应关系,而词序像似性是指词的组织形式和人的认知结构之间有某种对应关系,主要受四个原则支配:顺序像似原则、距离像似原则、与说话人接近原则和文化规约像似原则。正确理解词序像似性的概念和原则,对目标语的学习有重要的指导意义。     

Adaptive designs for IVPT data with mixed scaled average bioequivalence

In vitro permeation tests (IVPT) offer accurate and cost-effective development pathways for locally acting drugs, such as topical dermatological products. For assessment of bioequivalence, the FDA draft guidance on generic acyclovir 5% cream introduces a new experimental design, namely the single-dose, multiple-replicate per treatment group design, as IVPT pivotal study design. We examine the statistical properties of its hypothesis testing method—namely the mixed scaled average bioequivalence (MSABE). Meanwhile, some adaptive design features in clinical trials can help researchers make a decision earlier with fewer subjects or boost power, saving resources, while controlling the impact on family-wise error rate. Therefore, we incorporate MSABE in an adaptive design combining the group sequential design and sample size re-estimation. Simulation studies are conducted to study the passing rates of the proposed methods—both within and outside the average bioequivalence limits. We further consider modifications to the adaptive designs applied for IVPT BE trials, such as Bonferroni's adjustment and conditional power function. Finally, a case study with real data demonstrates the advantages of such adaptive methods.     

Modifications of sequential designs in bioequivalence trials

Bioequivalence (BE) studies are designed to show that two formulations of one drug are equivalent and they play an important role in drug development. When in a design stage, it is possible that there is a high degree of uncertainty on variability of the formulations and the actual performance of the test versus reference formulation. Therefore, an interim look may be desirable to stop the study if there is no chance of claiming BE at the end (futility), or claim BE if evidence is sufficient (efficacy), or adjust the sample size. Sequential design approaches specially for BE studies have been proposed previously in publications. We applied modification to the existing methods focusing on simplified multiplicity adjustment and futility stopping. We name our method modified sequential design for BE studies (MSDBE). Simulation results demonstrate comparable performance between MSDBE and the original published methods while MSDBE offers more transparency and better applicability. The R package MSDBE is available at https://sites.google.com/site/modsdbe/ . Copyright © 2015 John Wiley & Sons, Ltd.     

Group sequential monitoring based on the weighted log‐rank test statistic with the Fleming–Harrington class of weights in cancer vaccine studies

In recent years, immunological science has evolved, and cancer vaccines are now approved and available for treating existing cancers. Because cancer vaccines require time to elicit an immune response, a delayed treatment effect is expected and is actually observed in drug approval studies. Accordingly, we propose the evaluation of survival endpoints by weighted log‐rank tests with the Fleming–Harrington class of weights. We consider group sequential monitoring, which allows early efficacy stopping, and determine a semiparametric information fraction for the Fleming–Harrington family of weights, which is necessary for the error spending function. Moreover, we give a flexible survival model in cancer vaccine studies that considers not only the delayed treatment effect but also the long‐term survivors. In a Monte Carlo simulation study, we illustrate that when the primary analysis is a weighted log‐rank test emphasizing the late differences, the proposed information fraction can be a useful alternative to the surrogate information fraction, which is proportional to the number of events. Copyright © 2016 John Wiley & Sons, Ltd.     

Bias Reduction using Stochastic Approximation

The paper studies stochastic approximation as a technique for bias reduction. The proposed method does not require approximating the bias explicitly, nor does it rely on having independent identically distributed (i.i.d.) data. The method always removes the leading bias term, under very mild conditions, as long as auxiliary samples from distributions with given parameters are available. Expectation and variance of the bias-corrected estimate are given. Examples in sequential clinical trials (non-i.i.d. case), curved exponential models (i.i.d. case) and length-biased sampling (where the estimates are inconsistent) are used to illustrate the applications of the proposed method and its small sample properties.