Nonlinearity impairments and distortions have been bothering the bandwidth constrained passive optical network(PON)system for a long time and limiting the develop-ment of capacity in the PON system.Unlike other works ...Nonlinearity impairments and distortions have been bothering the bandwidth constrained passive optical network(PON)system for a long time and limiting the develop-ment of capacity in the PON system.Unlike other works concentrating on the exploration of the complex equalization algorithm,we investigate the potential of constellation shap-ing joint support vector machine(SVM)classification scheme.At the transmitter side,the 8 quadrature amplitude modulation(8QAM)constellation is shaped into three designs to mitigate the influence of noise and distortions in the PON channel.On the receiver side,simple multi-class linear SVM classifiers are utilized to replace complex equalization methods.Simulation results show that with the bandwidth of 25 GHz and overall bitrate of 50 Gbit/s,at 10 dBm input optical power of a 20 km standard single mode fiber(SSMF),and under a hard-decision forward error correction(FEC)threshold,transmission can be realized by employing Circular(4,4)shaped 8QAM joint SVM classifier at the maximal power budget of 37.5 dB.展开更多
Background Little is known about asthma control and perception of asthma among asthmatic patients in China.This study marked the first survey conducted on a national scale that aimed at obtaining baseline information ...Background Little is known about asthma control and perception of asthma among asthmatic patients in China.This study marked the first survey conducted on a national scale that aimed at obtaining baseline information on asthma control and patients＇ perception of asthma and providing a point of reference for future studies.Methods This face-to-face,questionnaire-based survey was conducted from April 2007 to March 2008 with 3 069 asthmatic patients from the respiratory outpatient clinics of 36 general hospitals located in 10 geographically dispersed cities.Results Consistent with the Global Initiative for Asthma （GINA） guidelines,28.7% and 45.0% of our patients achieved control and partial control,respectively.Of the patients in the study,only 21.8% had used a peak flow meter （PFM）,and 6.6% of these patients used it daily.Inhaled corticosteroids （ICS） plus a long-acting β2 agonist （LABA） and ICS were the two most common medication regimens and were used in 45.6% and 30.4% of patients,respectively.Asthma had a significant effect on the patients＇ life and work.A considerable number of hospitalizations,emergency department visits,and sick days were observed.Conclusion Despite improvements in asthma control and ICS and PFM compliance compared with past literature,the current level of asthma control countrywide continues to fall short of the goals set in the GINA.展开更多
文摘Nonlinearity impairments and distortions have been bothering the bandwidth constrained passive optical network(PON)system for a long time and limiting the develop-ment of capacity in the PON system.Unlike other works concentrating on the exploration of the complex equalization algorithm,we investigate the potential of constellation shap-ing joint support vector machine(SVM)classification scheme.At the transmitter side,the 8 quadrature amplitude modulation(8QAM)constellation is shaped into three designs to mitigate the influence of noise and distortions in the PON channel.On the receiver side,simple multi-class linear SVM classifiers are utilized to replace complex equalization methods.Simulation results show that with the bandwidth of 25 GHz and overall bitrate of 50 Gbit/s,at 10 dBm input optical power of a 20 km standard single mode fiber(SSMF),and under a hard-decision forward error correction(FEC)threshold,transmission can be realized by employing Circular(4,4)shaped 8QAM joint SVM classifier at the maximal power budget of 37.5 dB.
文摘Background Little is known about asthma control and perception of asthma among asthmatic patients in China.This study marked the first survey conducted on a national scale that aimed at obtaining baseline information on asthma control and patients＇ perception of asthma and providing a point of reference for future studies.Methods This face-to-face,questionnaire-based survey was conducted from April 2007 to March 2008 with 3 069 asthmatic patients from the respiratory outpatient clinics of 36 general hospitals located in 10 geographically dispersed cities.Results Consistent with the Global Initiative for Asthma （GINA） guidelines,28.7% and 45.0% of our patients achieved control and partial control,respectively.Of the patients in the study,only 21.8% had used a peak flow meter （PFM）,and 6.6% of these patients used it daily.Inhaled corticosteroids （ICS） plus a long-acting β2 agonist （LABA） and ICS were the two most common medication regimens and were used in 45.6% and 30.4% of patients,respectively.Asthma had a significant effect on the patients＇ life and work.A considerable number of hospitalizations,emergency department visits,and sick days were observed.Conclusion Despite improvements in asthma control and ICS and PFM compliance compared with past literature,the current level of asthma control countrywide continues to fall short of the goals set in the GINA.
