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1.
针对脉冲噪声下恒模算法(Constant Modulus Algorithm,CMA)失败的问题,通过分析脉冲噪声的影响,提出了一种基于最小均方(Least Mean Square,LMS)准则的对数型恒模算法(Logarithmic-type CMA,LT-CMA)。LT-CMA利用对数函数的非线性变换特性自适应地抑制强脉冲噪声对误差函数的影响,并且利用l2-范数进行信号归一化处理以增强算法的稳健性。仿真结果表明,所提出的LT-CMA可以适应于高斯噪声环境和脉冲噪声环境;与经典自适应均衡算法相比,在收敛速度和稳健性两方面上,所提出的LT-CMA都有显著的提升。 相似文献
2.
[目的]开展土地综合承载力评价是科学编制国土空间发展战略的基础。通过构建包含水土资源承载力、经济承载力和生态承载力3个维度土地综合承载力评价指标体系,定量刻画郑州市城市土地综合承载力的特征与轨迹。[方法]运用均方差法,选取2010—2016年郑州市城市土地综合承载力评价指标,分析其土地综合承载力特征。[结果](1)总体上,郑州市城市土地综合承载力不断增强,水土资源承载力呈现先升—降—升的动态演变特征; 经济承载力持续增长,这源于郑州市土地经济效益的大幅提升; 生态承载力呈现波动性增强的演变特征。(2)郑州市城市土地综合承载力经历了较低—中等—较高发展历程,但土地综合承载力处于低层次的较高阶段,仍有较大提升空间。(3)为提高郑州市城市土地综合承载力,应加快“多规合一”规划的编制,科学划定城市增长边界和“三生”空间,转变城市发展理念,优化发展发展路径,提升城市土地综合承载力水平。[结论]郑州市城市土地综合承载力仍有较大提升空间,应加快建立土地综合承载力扩容的有效机制。 相似文献
3.
Yusuf Ekrem Akbas 《Applied economics》2020,52(25):2705-2722
ABSTRACTIn this study, we investigated whether the exchange rate and the interest rate had an effect on the inflation rate in the fragile five countries between the years of 1996Q4 and 2015Q4. In this context, a model was created to estimate the effect of interest rate and exchange rate on the inflation rate. The methods used in the study take into account cross-section dependence and heterogeneity. As a result of the analysis, it was determined that there was an exchange-rate and interest-rate pass-through effect in the fragile five countries. Moreover, it was found out that the cost channel and price puzzle were effective in Indonesia and South Africa but were not effective in Turkey, Brasil and India. 相似文献
4.
In their out-of-sample predictions of stock returns in the presence of structural breaks, Lettau and Van Nieuwerburgh (2008) implicitly assume that economic agents’ perception of the regime-specific mean for the dividend-price ratio is time-invariant within a regime. In this paper, we challenge this assumption and employ least squares learning with constant gain (or constant-gain learning) in estimating economic agents’ time-varying perception for the mean of dividend-price ratio. We obtain better out-of-sample predictions of stock returns than in Lettau and Van Nieuwerburgh (2008) for both the U.S. and Japanese stock markets. Our empirical results suggest that economic agents’ learning plays an important role in the dynamics of stock returns. 相似文献
5.
在经典的投资组合理论中 ,假设所有资产的报酬率服从对数正态分布 ,因而只需要用收益的方差来度量风险就足够了 ,忽略了偏度的影响。资产收益的分布往往不是对称的 ,偏度是客观存在的 ,而且投资者具有正偏度的爱好。所以必须用方差和偏度来共同度量投资的风险 ,在这种情况下 ,贝塔系数不再是风险的正确度量 ,采用有效的修正方法 ,可以用来对资产进行正确的定价 相似文献
6.
7.
This paper was to price and hedge a quanto floating range accrual note (QFRAN) by an affine term structure model with affine-jump processes. We first generalized the affine transform proposed by Duffie et al. (2000) under both the domestic and foreign risk-neutral measures with a change of measure, which provides a flexible structure to value quanto derivatives. Then, we provided semi-analytic pricing and hedging solutions for QFRAN under a four-factor affine-jump model with the stochastic mean, stochastic volatility, and jumps. The numerical results demonstrated that both the common and local factors significantly affect the value and hedging strategy of QFRAN. Notably, the factor of stochastic mean plays the most important role in either valuation or hedging. This study suggested that ignorance of these factors in a term-structure model will result in significant pricing and hedging errors in QFRAN. In summary, this study provided flexible and easily implementable solutions in valuing quanto derivatives. 相似文献
8.
《Socio》2021
The present inquiry lays a groundwork for the analysis of the net greenhouse gas (GHG) footprint of oil in the oil-abundant settings. To address the research question, the study puts forward a three-sector decision model, which provides a common ground for the assessment of the interaction of the structuralist and institutional factors influencing environmental pollution in the oil-reliant economies. The study shows that fossil-fuel abundance triggers forces, which induce diametrically opposed effects concerning atmospheric pollution. These are the rising carbon-intensive oil extraction and processing and fossil-fueled power generation versus shrinkage of the carbon-intensive manufacturing and growth of the low-carbon tertiarization. The theoretical analysis enables compartmentalization of the essential factors, which determine GHG emissions in the respective countries. To assess the significance of the proposed theoretical framework, the study employs multivariate panel co-integration techniques and two-stage fixed effects estimations for a dataset of 38 oil-producing countries for the time period between 1960 and 2018. In contrast to the existing literature, this study drives apart from the black box approaches that employ just one omnibus variable, per capita income. 相似文献
9.
针对高家庄煤矿副立井表土段掘进施工过程中出现的片帮事故,通过分析不同状态下发生片帮的原因,最终确定了高家庄煤矿井田地质条件下,采用缩小模板段高措施治理表土段片帮的技术方案,为井田内类似条件下施工提供了有效地治理技术。 相似文献
10.
In this article, we consider the portfolio selection problem as a Bayesian decision problem. We compare the traditional mean–variance and mean–variance–skewness efficient portfolios. We develop bi-level programming problem to investigate the market’s preference for risk by using observed (market) weights. Numerical experiments are conducted on a portfolio formed by the 30 stocks in the Dow Jones Industrial Average. Numerical results show that the market’s preferences are better explained when skewness is included. 相似文献