桥头深厚软基处理中低强度桩的应用分析

结合某桥头段桥头深厚软基处理的工程实例,探讨了低强度桩处理桥头软基的机理和设计思路。     

人民币汇率波动对NFDI波动的影响及其检验

本文通过对我国NFDI资本流动性及其波动性的计算,检验了人民币/美元汇率波动对NFDI波动性的关系。通过实证分析表明,人民币汇率的波动将导致NFDI资本流动的明显不稳定。在理论研究的基础上,引申出其政策含义：在国际资本流动不断加大的今天,我们必须维护人民币/美元汇率的稳定,这样对于有效引导NFDI的资本流动和维护金融稳定都具有重要的意义。     

Robust estimation with flexible parametric distributions: estimation of utility stock betas

The distributions of stock returns and capital asset pricing model (CAPM) regression residuals are typically characterized by skewness and kurtosis. We apply four flexible probability density functions (pdfs) to model possible skewness and kurtosis in estimating the parameters of the CAPM and compare the corresponding estimates with ordinary least squares (OLS) and other symmetric distribution estimates. Estimation using the flexible pdfs provides more efficient results than OLS when the errors are non-normal and similar results when the errors are normal. Large estimation differences correspond to clear departures from normality. Our results show that OLS is not the best estimator of betas using this type of data. Our results suggest that the use of OLS CAPM betas may lead to erroneous estimates of the cost of capital for public utility stocks.     

ECONOMIC SANCTIONS REVISITED: ADDITIONAL INSIGHTS INTO WHY THEY FAIL

Economic sanctions have a poor track record in achieving their objectives. In most cases, they are ineffective in bringing about policy change, cause increased suffering in the sanctioned country and reduce opportunities for business. This paper provides additional insights into why sanctions fail by examining two overlooked factors: power–dependency theory and pressure for political stability.     

Trade‐led growth hypothesis in Cuban commercial regimes since 19601,2

This study examines the impact of trade on Cuban growth during different commercial policy regimes spanning the period from 1960 up to 2004, encompassing two essential economic structural transformations: the Cuban revolution and the fall of the Berlin Wall. For this purpose, the Granger causality is used by means of the modified Wald test for augmented‐level vector autoregressive model with integrated and cointegrated processes introduced by Toda and Yamamoto (1995) and Dolado and Lutekepohl (1996) . We show an import‐led growth hypothesis during the Soviet‐oriented pattern that is rejected after 1990, when exports are not only responsive to growth expansion but also to imports’ behaviour.     

均料分配系统中环形同轨自动导引车的应用研究

依据均料分配系统的结构布局和物流规划目标,设计了以料箱为输送单元能够倾翻卸货的环形轨道式自动导引车,实现了多个接料口到多个粉碎机间均料分配。该小车能够满足均料分配系统的生产需求,可应用于企业循环流通生产物流系统中。     

基于K空间的核磁共振快速成像技术

磁共振成像技术已经成为现代临床医学影像检查的重要手段之一,而传统的成像手段的主要缺点是其成像速度太慢。文章主要阐述了半傅里叶成像、平行成像以及压缩传感成像的基本原理,从而展现MR快速成像技术巨大的应用价值和研究价值。     

Efficiency of the Banking Industry Structure in Korea*

This paper analyzes whether the efficiency of the Korean banking industry has improved since the bank restructuring in 1997, and whether a bank with high efficiency has a larger market share. This paper uses an efficient structure hypothesis model to examine the relationship between the banks' efficiencies and their profitability. The data envelopment analysis method is applied to measure the efficiency and profitability of the banking industry in order to minimize possible bias due to the inflow of public funds for the bank consolidation. The two‐step Heckman selection method is used to correct for survivorship bias in the model. The derived result indicates that banks with higher efficiencies tend to record higher profit. Moreover, higher pure technological efficiency and scale efficiency have a positive effect on a bank's market share and concentration.     

Design considerations for neyman-pearson and wald hypothesis testing

Summary The Neyman-Pearson Lemma describes a test for two simple hypotheses that, for a given sample size, is most powerful for its level. It is usually implemented by choosing the smallest sample size that achieves a prespecified power for a fixed level. The Lemma does not describe how to select either the level or the power of the test. In the usual Wald decision-theoretic structure there exists a sampling cost function, an initial prior over the hypothesis space and various payoffs to right/wrong hypothesis selections. The optimal Wald test is a Bayes decision rule that maximizes the expected payoff net of sampling costs. This paper shows that the Wald-optimal test and the Neyman-Pearson test can be the same and how the Neyman-Pearson test, with fixed level and power, can be viewed as a Wald test subject to restrictions on the payoff vector, cost function and prior distribution.