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The Effect and Compensation of Phase Noise on Orthogonal Frequency Division Multiplexing (OFDM) System

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Circuits and Systems 2018年第7期9卷 107-115页

作者： Yubin Lin Greater Atlanta Christian school Norcross Georgia USA

Orthogonal Frequency Division Multiplexing (OFDM) is characterized by its high data rate. However, the modulation method used in the system is subject to the influence of phase noise due to the need of time synchronization. In this paper, an algorithm based on MMSE (minimum mean square error) is developed to compensate the influence of both the common phase error (CPE) and inter carrier interference (ICI), which are two aspects of phase noise, under common Gaussian white noise. The result of noise cancellation is presented in signal-to-noise ratio (SNR) and symbol error rate (SER). Like digital signal in general, SNR can reduce SER with or without phase noise compensation. The compensation of phase noise significantly reduces the SER of the decoded signal. However, the bandwidth of phase noise still determines the signal accuracy. Under high bandwidth of phase noise, increasing SNR will only slightly increase SER, which is not efficient.

关键词： Orthogonal Frequency Division Multiplexing Phase Noise Mean Square Error

Financial Development, Foreign Direct Investment, and the Efficiency of Capital Allocation in China

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2013年第2期8卷 165-185页

作者： Kevin X. D. Huang Chun Jiang Qingyuan Li Kai Sheng Jia Wang QiweiZhao Department of Economics Vanderbilt University Nashville TN 37235-1819 USA school of Economics and Management Wuhan University Wuhan 430072 ChinaJia Wang World Financial Group 3300 Holcomb Bridge Road Norcross GA 30092-5405 USAKai Sheng school of Mathematical Sciences Peking University Beijing 100871 China

We study the roles of local financial development and foreign direct investment, and more importantly, their interaction with one another, in local capital allocation, based on Chinese industrial and regional data. Our main finding is that, although local financial development and FDI each individually tended to improve the efficiency of local capital allocation during the sample period, they tended to compete and crowd out each other＇s effect, so that one impaired the individual function of the other. In particular, there exists a threshold value for local financial development, above which an increase in FDI reduces the efficiency of local capital allocation, rather than improve it. On the other hand, there exists a threshold value for FDI, above which further development in the local financial system lowers the efficiency of local capital allocation, rather than increase it. Our estimations suggest that the levels of FDI and local financial development in some relatively more developed Chinese regions have already surpassed such threshold values. We provide some interpretations of our findings and we discuss potential policy implications.

关键词： foreign direct investment （FDI） local financial development,capital allocation efficiency

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在心脏舒张的心失败进展

World Journal of Cardiology 2010年第3期2卷 58-63页

作者： Xing Sheng Yang Jing Ping Sun Xing Sheng Yang Jing Ping Sun Department of Caediology Emory University School of Medicine 6276 Courtside Drive Norcross GA 30092 United States.

More than 50% of people living with congestive heart failure have diastolic heart failure(DHF).Most of them are older than 70 years,and female.The prevalence of DHF has increased with time.DHF is caused by left ventricular(LV) diastolic dysfunction(DD) which is induced by diastolic dyssynchrony.Cardiac and extracardiac factors play important roles in the development of heart failure(HF) symptoms.The diagnosis of DHF is generally based on typical symptoms and signs of HF,preserved or normal LV ejection fraction,DD and no valvular abnormalities on examination,using noninvasive and invasive methodologies.The outcomes with pharmacological therapy in patients with DHF are frequently neutral in clinical trials,and prognosis still remains poor with a 5-year mortality of 42.3% after hospitalization for HF.Further trials are necessary.

关键词： B-type natriuretic peptide Diastolic dysfunction Diastolic dyssynchrony normal ejection fraction Diastolic heart failure Echocardiography Heart failure

In vitro fermentation characteristics of human milk oligosaccharides by different dominating infant microbiota

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In vitro fermentation characteristics of human milk oligosac...

Stroke and Cardiovascular Disease among Women

中国营养学会第十五届全国营养科学大会

作者： Shiqi Xu Hongye Li Feitong Liu Bin Zhang Jonathan Lane school of Food Science and Engineering South China University of Technology

This study investigated the in vitro fermentation profiles of human milk oligosaccharides(HMOs) by different dominating infant microbiota(B.longum-, B.breve-and Bacteroides-dominated inocula). We sought to evaluate fecal microbiota composition of healthy infant donors in Guangzhou(including breast-feeding and formula-feeding). Further, we were expected to study in vitro fermentation outcomes of six commercial HMOs [i.e., 2 -fucosyllactose(2 -FL), 3-fucosyllactose(3-FL), 3 -sialyllactose(3 -SL), 6 -sialyllactose(6 -SL), lacto-Ntetraose(LNT) and lacto-N-neotetraose(LNnT)], fructo-oligosaccharide(FOS) and galacto-oligosaccharides(GOS) by using individual infant fecal inocula. Methods Nineteen healthy donors were selected at Guangzhou, China. Nine infants were qualified and enrolled in the experiment. Each 50 mg of carbohydrate sample was equivalently weighted into anaerobic tubes and fermented with fecal slurry at 37 °C water bath with gentle shaking for various time periods. Total gas production of each tube was measured by inserting the needle through rubber stopper with a graduated syringe. The concentration of short chain fatty acids(SCFAs) was determined by gas chromatography, and the concentration of organic acids(OAs) was determined by high performance liquid chromatography. DNA extraction from the fermented products was performed using the OMEGA Soil DNA Kit(M5635-02)(Omega Bio-Tek, norcross, GA, USA), following the manufacturer s instruction. The nearly full-length bacterial 16 S rRNA from each purified DNA sample was performed to investigate microbiota composition. Results Fecal microbiota composition and microbiota classification It was noteworthy that three distinct clusters of infant gut microbiota were shown among nineteen infants. Three distinct groups were characterized by the bacteria abundance, denoted as B. longum-, B. breve-and Bacteroides-dominated inocula. Gas production In the early stage of fermentation(0-4 h), gas production of B. breve-dominated inocula was higher than other microbiota type

关键词： human milk oligosaccharides fermentation characteristic infant gut microbiota

来源： cnki会议评论

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Health 2015年第14期7卷 1847-1854页

作者： Hengameh Hosseini Certificate Program in Long-Term Care School of Public Affairs Penn State University Middletown USA

Stroke falls under the umbrella of cardiovascular disease (CVD), which is the number one killer of Americans. CVD, including stroke and heart disease, takes about 267,000 women’s lives every year [1]. In the present study, a health risk assessment of a population of women residing in North-eastern Pennsylvania was conducted to provide an estimate of vulnerability to stroke on the basis of medical history, genetic predisposition, and other lifestyle factors. Using the Health Belief model of Rosenstock, Strecher, and Becker [2] and the stage model of Prochaska, Diflemente, and norcross [3], a health promotion plan was developed to address the needs of that population. An evaluation of risks that can and cannot be modified is developed to help people understand the basic lifestyle changes that could be made to prevent CVD, which includes stroke. An action plan was developed to lower the risk of stroke among women based on their individual needs and to raise awareness throughout the United States. Individuals should take the essential precautions for their personal cases. This will substantially lower the risk of CVD, especially stroke, among women.

关键词： Cardiovascular Disease Stroke among Women Risk Factors Life Style Health Belief Model