三极管极间电容对放大电路高频特性影响的教学探讨

引导学生应用电路分析基础知识对晶体管的混合π型等效电路进行化简,等效和公式推导得出三极管极间电容对三种基本放大电路高频特性的不同影响。     

地理教学中自然美的展现方式及美育价值

中考英语的书面表达,在中考的考试中一直占有较大的比例,并有越来越增加的趋势。进行中考英语书面表达时,应该做到认真审题,准确破题和规范做题;要求能够做到语言精简而合呼习惯,书法整齐且词语有限,灵活表达则严格规范。     

我国高等职业教育存在的问题及发展对策分析

我国高等职业教育的发展时间不长 ,也取得了很多的成果。但是从目前看 ,还缺少示范性 ,缺少特色 ,培养出的对象质量不高 ,发展的制约性因素较多 ,内涵型的发展不够 ,生源过于单一。对此 ,必须采取积极有效的措施 ,加强高等教育的内涵型发展。     

深井钻井的压力平衡研究

深井钻井具有高温高压及地层压力和地层破裂压力间安全钻井液密度窗口极为狭窄的特点,这为在深井钻井过程中保持井眼系统的压力平衡提出了更高的要求。为此,针对深井钻井的特点,运用流变学、传热学和物质平衡的基本原理,建立钻井液循环和静止状况下的钻井液温度分布模式及高温高压密度模式和高温高压流变模式,应用这些模式和地层流体的PVT特性对一些实钻深井的溢流现象进行分析。结果表明,井眼水力系统流体热力学模型对深井、超深井的压力平衡控制至关重要。     

不能回避的建构之失——“实践存在论”美学体系的几个问题

学界对马克思主义美学的哲学基础问题进行了历时弥久的激烈争论,朱立元认为传统认识论是一种二元对立的思维模式,建立在这样一种思维模式基础上的实践论美学势必需要得到新的发展,由此提出了＂实践存在论＂美学。就学术思想探索的精神而言,朱立元于当代提出＂实践存在论＂有其价值所在,但就其美学建构过程看,仍然在历史性和辩证性论证方面存在着难以回避的问题甚至是缺陷,这些问题足以削弱甚至摧毁＂实践存在论＂建构的合理性和可行性。     

对云南走新型工业化道路的思考

走新型工业化道路在实践中能否取得良好的效果，一方面取决于如何将这种增长模式与实际相结合，另一方面取决于这种增长模式赖以存在和发展的制度、政策和经济等诸环境。作者结合实际，对云南省推进新型工业化道路中政府的作用、资源性工业结构的转换、新型工业化与农业产业化和城市化、高新技术产业区建设对新型工业化的作用等问题进行探讨。     

A martingale approach to the problem of dimensionality and performance of bayesian classifiers: asymptotic results

A martingale approach to the problem of performance of Bayesian classifiers with increasing feature dimensionality is applied here . Martingale limit theorems are also used to demonstrate that the expected probability of correct classification tends monotonically to unity for two general classification problems.     

Asymptotic properties for multipower variation of semimartingales and Gaussian integral processes with jumps

This paper presents limit theorems of realized multipower variation for semimartingales and Gaussian integral processes with jumps observed in high frequency. In particular, we obtain a central limit theorem of realized multipower variation for semimartingale where some of the powers equal one and the others are less one. Convergence in probability and central limit theorems of realized threshold bipower variation for Gaussian integral processes with jumps are also obtained. These results provide new statistical tools to analyze and test the long memory effect in high frequency situation.     

Testing linear hypotheses of mean vectors for high-dimension data with unequal covariance matrices

We propose a new test procedure for testing linear hypothesis on the mean vectors of normal populations with unequal covariance matrices when the dimensionality, p exceeds the sample size N  , i.e. p/N→c<∞$p/N\to c<\infty$. Our procedure is based on the Dempster trace criterion and is shown to be consistent in high dimensions.     

Nonparametric Estimation Methods of Integrated Multivariate Volatilities

Estimation of integrated multivariate volatilities of an Itô process is an interesting and important issue in finance, for example, in order to evaluate portfolios. New non-parametric estimators have been recently proposed by Malliavin and Mancino (2002 Malliavin , P. , Mancino , M. ( 2002 ). Fourier series method for measurement of multivariate volatilities . Finance and Stochastics 6 : 49 – 61 .[Crossref], [Web of Science ®] , [Google Scholar]) and Hayashi and Yoshida (2005a Hayashi , T. , Yoshida , N. (2005a). On covariance estimation of nonsynchronously observed diffusion processes. Bernoulli 11(2):359–379.[Crossref], [Web of Science ®] , [Google Scholar]) as alternative methods to classical realized quadratic covariation. The purpose of this article is to compare these alternative estimators both theoretically and empirically, when high frequency data is available. We found that the Hayashi–Yoshida estimator performs the best among the alternatives in view of the bias and the MSE. The other estimators are shown to have possibly heavy bias mostly toward the origin. We also applied these estimators to Japanese Government Bond futures to obtain the results consistent with our simulation.