基于加权全局时频特征的易混淆词识别

针对易混淆词特征差异小,分类决策困难的特点,提出了一种新的语音识别特征。该特征可以根据待识单词的发音特点,通过选用合适的基函数及加权处理,突出混淆词特征之间的差异性;     

VRML对CAPP的仿真应用

CAPP(Computer Aided Process Planning)是计算机辅助工艺设计的简称.用CAPP设计的工艺文件在应用于生产实践之前进行仿真,以检查工艺文件的合理性.本文采用虚拟现实操作语言(VRML)和由CAPP产生的半自动插件机工艺文件实现半自动插件流程的仿真.     

乳酸正丁酯的简易合成

无水氯化钙为催化剂,乳酸、正丁醇直接酯化合成乳酸正丁酯.考察了催化剂用量、反应原料比、酯化时间等因素对合成反应的影响,在最佳反应条件下,酯合成产率为76.2%.     

我国淡水水产品加工业的现状与前景展望

通过分析我国水产品养殖业和加工业的现状、存在问题以及人们将来对淡水水产品深精加工食品的需求趋势,指出我国应该大力发展淡水鱼的深精加工技术,生产淡水鱼深精加工方便食品,以满足人们对营养、方便、卫生食品的需求。     

Bias in the estimation of non‐linear transformations of the integrated variance of returns

Volatility models such as GARCH, although misspecified with respect to the data‐generating process, may well generate volatility forecasts that are unconditionally unbiased. In other words, they generate variance forecasts that, on average, are equal to the integrated variance. However, many applications in finance require a measure of return volatility that is a non‐linear function of the variance of returns, rather than of the variance itself. Even if a volatility model generates forecasts of the integrated variance that are unbiased, non‐linear transformations of these forecasts will be biased estimators of the same non‐linear transformations of the integrated variance because of Jensen's inequality. In this paper, we derive an analytical approximation for the unconditional bias of estimators of non‐linear transformations of the integrated variance. This bias is a function of the volatility of the forecast variance and the volatility of the integrated variance, and depends on the concavity of the non‐linear transformation. In order to estimate the volatility of the unobserved integrated variance, we employ recent results from the realized volatility literature. As an illustration, we estimate the unconditional bias for both in‐sample and out‐of‐sample forecasts of three non‐linear transformations of the integrated standard deviation of returns for three exchange rate return series, where a GARCH(1, 1) model is used to forecast the integrated variance. Our estimation results suggest that, in practice, the bias can be substantial. Copyright © 2006 John Wiley & Sons, Ltd.     

A possible metabolic role foro-diphenoloxidase inMycobacterium leprae

Summary Among mycobacteria,Mycobacterium leprae is unique in its ability to oxidize a variety of diphenols to quinones in vitro. What physiologic roleo-diphenoloxidase has in the organism remained unknown. Reducing substrates like NADPH, NADH and ascorbic acid reacted with the quinone formed from dopa (3,4-dihydroxyphenylalanine); the substrates were oxidized and the quinone was reduced back to diphenol in the process. Since the quinone undergoes reversible oxidation-reduction, diphenoloxidase might serve as an alternative respiratory mechanism inM. leprae for the utilization of other substrates, as has been reported in plants.