LT码新型度分布及其在电力线通信中的应用

Luby变换(Luby Transform,LT)码作为信道编码应用于电力线通信(Power Line Communication,PLC)，可实现电信号的可靠传输。度分布对LT码编译码性能的影响至关重要。为了得到更优的度分布，首先调整二进制指数分布(Binary Exponential Distribution,BED)中的度数比例，获得一种译码性能更优的改进的二进制指数分布(Improved BED,IBED)。然后，根据IBED在冗余度较小时译码成功率高，而冗余度增大后鲁棒孤子分布(Robust Soliton Distribution,RSD)的译码性能表现更佳的特点，通过求和归一化的方式将IBED与RSD两种度分布的优势进行有机结合，提出一种新型二进制鲁棒孤子分布(Binary RSD,BRSD)。仿真结果表明，与其他方法及传统的RSD相比，采用新度分布进行LT编码，可明显降低译码开销，并节约编译码耗时。将新型度分布应用于基于LT码的PLC系统中，能有效地抑制PLC信道中各种噪声对电信号的干扰，并提高通信效率。     

发挥校园网在现代教育教学中的作用

随着信息技术在教育领域的应用不断发展，校园网在现代教育教学中的作用越来越重要。本文就校园网对现代教育模式变革的影响，以及目前校园网在使用中存在问题与对策等问题作了一些探讨。     

基于二进小波分析的电力系统瞬态信号研究

在多分辨率分析的基础上,采用二进正交小波变换对电力系统暂态信号进行了分析.将信号分解成许多细节部分和平滑部分(分别是信号的高频部分和细节部分),通过分析信号在各个尺度下的细节部分,从而可以对暂态信号的时域和频域进行定位.实验结果证实了方法的有效性.     

基于级联型组合分类器的人脸识别研究

该文提出了一种将支持向量机（SVM）与神经网络相结合的方法，得到一种新型的级联型组合分类器．此组合分类器先利用神经网络或SVM对人脸图像进行预分类，得到不同性别的两类人脸图像；然后分别针对其中某一类人脸图像进行K-I。变换以提取有效特征，再使用SVM进行细分，得到最终的识别结果．应用该组合分类器方法在本文整合得到的人脸样本库上进行测试，结果显示该方法不但可以有效地提高识别速度，而且还可以在一定程度上提高识别率，因此方法是有成效和有价值的．     

Bank loan versus financial lease: how do traditional and innovative approaches within the banking sector influence economic growth? A comparative analysis between the US and China

ABSTRACT

The argument over the effects of financial structures on economic growth remains unsettled. This study, therefore, compares the dynamic correlation and lead–lag relationship between the different financial approaches within the banking sector (that is, traditional bank loans versus innovative financial leasing) and economic growth. We employ a continuous wavelet analysis using time-series data from 1982–2017 from the US (the world’s largest developed country) and China (the world’s largest developing country). The empirical results show that (1) episodes of significant correlation usually emerge during periods of reform, crisis or policy implementation; and (2) in China, traditional banking promotes economic growth in the long term, while the real economy only imputes the evolution of banks during critical economic reforms in the short term. Meanwhile, financial leasing could only promote the development of the real economy under suitable regulation; and (3) in the US, before the crises, the irrational growth of the real economy could increase bank assets, while during the crises, the traditional banking approach harms economic growth, and after the crises, financial leases play an important role in recovery. Therefore, we suggest that policymakers should establish adequate policies and regulations to solve the situation.     

体制变革背景下的服务业增长：一个定量分析框架

1978-2006年，中国服务业的高速增长与经济体制变革存在着直接的关系。体制变革是过去20多年中服务业增长的一个最重要因素。体制变革一方面通过放松管制提高了服务业占GDP的比重，另一方面，体制变革通过民营化进程降低了服务业的内部产业X-无效率，提高了服务业的金要素生产率。     

基于小波神经网络的企业技术创新能力模糊综合评价

在对企业技术创新能力系统进行分析的基础上,建立了企业技术能力评价指标体系并提出了基于小波神经网络的综合评价方法,采用模糊综合评价法生成评价样本集。仿真试验表明该方法用于企业技术创新能力综合评价的有效性与准确性,为企业技术创新能力的评价研究提供了一种新的模型。     

新一轮税制改革面临的挑战与现实选择

中国经济正面临着知识经济、经济全球化、可持续发展、通货紧缩、追求收入公平分配等方面的严峻挑战。制定税收制度必须以经济转轨时期的经济改革为背景,以广税基、低税率、少优惠、强征管为目标,进一步深化我国的税制改革。     

Exploring Portfolio Diversification Opportunities Through Venture Capital Financing: Evidence from MGARCH-DCC,Markov Switching,and Wavelet Approaches

Islamic financial institutions are being pressurized by critics to offer profit and loss sharing (PLS) financing, such as venture capital (VC) financing, for the purpose of entrepreneurial development aligned to the principle of equity risk sharing. Our study aims to link PLS investments with portfolio optimization opportunities for the Islamic asset managers. Using portfolio analysis with dynamic conditional correlation, Markov switching, and maximal overlap discrete wavelet transformation, our findings tend to indicate that there is indeed a portfolio optimization opportunity in investment universe for the fund managers who invested in PLS investments in the context of VC asset class over the long run.     

A Multiple and Partial Wavelet Analysis of the Oil Price,Inflation, Exchange Rate,and Economic Growth Nexus in Saudi Arabia

This article provides a fresh insight into the dynamic nexus between oil prices, the Saudi/US dollar exchange rate, inflation, and output growth rate in Saudi Arabia’ economy, using novel Morlet’ wavelet methods. Specifically, it implements various tools of methodology: the continuous wavelet power spectrum, the cross-wavelet power spectrum, the wavelet coherency, the multiple and the partial wavelet coherence to the annual sample period 1969–2014. Our results unveil that the relationships among the variables evolve through time and frequency. From the time-domain view, we show strong but non-homogenous linkages between the four variables. From the frequency-domain view, we uncover significant wavelet coherences and strong lead-lag relationships. From an economic view, the wavelet analysis shows that Saudi economy is still exposed to several global risk factors, which are mainly related to the oil market volatility, and the pegging of the local currency to the US dollar. Such risk factors strongly and negatively affect the real economic growth, exert more pressure on inflation, and substantially limit the freedom to pursue an independent monetary policy.