本研究通过特征选择的方法,分析肝癌患者术前临床信息,提高患者的预后模型的准确性。基于多类支持向量机递归特征消除(recursive feature elimination based on multiple support vector machine,MSVM-RFE)方法对进行过肝切除手术的原...本研究通过特征选择的方法,分析肝癌患者术前临床信息,提高患者的预后模型的准确性。基于多类支持向量机递归特征消除(recursive feature elimination based on multiple support vector machine,MSVM-RFE)方法对进行过肝切除手术的原发性肝癌患者的临床变量进行重要特征排序,使用5折交叉验证的支持向量机确定最优特征子集,构造原发性肝癌患者术后的1年、3年无瘤生存和总体生存的列线图。通过与临床医生沟通,确认特征排序结果为合理的。患者3年无瘤生存风险和总生存风险的列线图的一致性指数分别为0.701和0.706。使用多类支持向量机递归特征消除方法后的预测模型准确率有所提高,列线图在临床实践中能够提供患者生存风险信息,简单清晰的反映患者的生存风险。展开更多
A direct conversion receiver with optimized tolerance to local carrier interference is designed and implemented in a 0.18μm 1P6M mixed-signal CMOS process for a 900MHz RFID reader transceiver. A baseband amplifier wi...A direct conversion receiver with optimized tolerance to local carrier interference is designed and implemented in a 0.18μm 1P6M mixed-signal CMOS process for a 900MHz RFID reader transceiver. A baseband amplifier with series feedback topology is proposed to achieve passive mixer buffering,baseband DC cancellation,and signal amplification simultaneously. The receiver has a measured input ldB compression point of - 4dBm and a sensitivity of - 70dBm when 10dB SNR for digital demodulation is required. The receiver is integrated in a reader transceiver chip and consumes 90mA from a 1.8V supply.展开更多
The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the fr...The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the friction behavior of fibers,and the difference is largely responsible for the "stick-slip" motion of fibers which causes the drafting waves during drafting.In this paper,it's expected that when a high frequency undulating wave is imposed on the fiber strand in the drafting zone of roller system,the friction among fibers is dominated by the dynamic friction rather than the static friction,and thus the "stick-slip" motion will be eliminated.As a result,the fiber binding effect causing drafting waves can be significantly reduced.This hypothesis is verified by an experiment,and it can be applied in developing new spinning drafting device.展开更多
Video object segmentation is important for video surveillance, object tracking, video object recognition and video editing. An adaptive video segmentation algorithm based on hidden conditional random fields (HCRFs) is...Video object segmentation is important for video surveillance, object tracking, video object recognition and video editing. An adaptive video segmentation algorithm based on hidden conditional random fields (HCRFs) is proposed, which models spatio-temporal constraints of video sequence. In order to improve the segmentation quality, the weights of spatio-temporal con- straints are adaptively updated by on-line learning for HCRFs. Shadows are the factors affecting segmentation quality. To separate foreground objects from the shadows they cast, linear transform for Gaussian distribution of the background is adopted to model the shadow. The experimental results demonstrated that the error ratio of our algorithm is reduced by 23% and 19% respectively, compared with the Gaussian mixture model (GMM) and spatio-temporal Markov random fields (MRFs).展开更多
Headphones with an integrated active noise cancellation system have been increasingly introduced to the consumer market in recent years. When exposing the human ear to active noise sources in this striking distance, t...Headphones with an integrated active noise cancellation system have been increasingly introduced to the consumer market in recent years. When exposing the human ear to active noise sources in this striking distance, the ensuring of a safe sound pressure level is vital. In feedback systems, this is coupled with the stability of the closed control loop; stable controller design is thus essential. However, changes in the control path during run-time can cause the stable control system to become unstable, resulting in an overdrive of the speakers in the headphones. This paper proposes a method, which enables the real-time analysis of the current system state and if necessary stabilizes the closed loop while maintaining the active noise reduction. This is achieved by estimating and evaluating the open loop behavior with an adaptive filter and subsequently limiting the controller gain in respect to the stability margin.展开更多
Objective:Percutaneous radiofrequency ablation(PRFA) is known to be as effective as hepatectomy for small hepatocellular carcinoma(HCC) in the long-term.We wished to ascertain how it is for recurrent small HCC.Methods...Objective:Percutaneous radiofrequency ablation(PRFA) is known to be as effective as hepatectomy for small hepatocellular carcinoma(HCC) in the long-term.We wished to ascertain how it is for recurrent small HCC.Methods:From January 2009 to November 2011,a series of sixty-one patients were included in the study according to the criteria:each patient had one recurrent HCC,less than 5 cm in diameter.Twenty-six of the 61 patients were treated with PRFA and the other 35 were treated with repeat hepatectomy.Results:The interval from first surgery to recurrent for repeat hepatectomy and PRFA groups were(1,239.60±1,017.00) d and(903.42±975.11) d respectively(P=0.066).The tumor-free time after repeat hepatectomy and PRFA were(310.23±159.50) d and(278.27±123.29) d respectively(P=0.584).Size of tumor in repeat hepatectomy and PRFA were(7.34±3.16) cm^2 and(5.59±3.40) cm^2(P=0.215),the total expenditure for each patient of the two groups were(26,150.66±7,923.60) yuan and(21,135.00±1,156.76) yuan(RMB),and the time of hospitalization for each of the two groups were(15.29±4.28) d and(7.46±2.20) d(P<0.001).Conclusion:PRFA is proved to be as effective as repeat hepatectomy in the treatment of recurrent small HCC,and superior to repeat hepatectomy as it is less invasive.展开更多
文摘本研究通过特征选择的方法,分析肝癌患者术前临床信息,提高患者的预后模型的准确性。基于多类支持向量机递归特征消除(recursive feature elimination based on multiple support vector machine,MSVM-RFE)方法对进行过肝切除手术的原发性肝癌患者的临床变量进行重要特征排序,使用5折交叉验证的支持向量机确定最优特征子集,构造原发性肝癌患者术后的1年、3年无瘤生存和总体生存的列线图。通过与临床医生沟通,确认特征排序结果为合理的。患者3年无瘤生存风险和总生存风险的列线图的一致性指数分别为0.701和0.706。使用多类支持向量机递归特征消除方法后的预测模型准确率有所提高,列线图在临床实践中能够提供患者生存风险信息,简单清晰的反映患者的生存风险。
基金the Science and Technology Commission of Shanghai Municipality(No.057062010)the EU BRIDGE Project(No.033546)~~
文摘A direct conversion receiver with optimized tolerance to local carrier interference is designed and implemented in a 0.18μm 1P6M mixed-signal CMOS process for a 900MHz RFID reader transceiver. A baseband amplifier with series feedback topology is proposed to achieve passive mixer buffering,baseband DC cancellation,and signal amplification simultaneously. The receiver has a measured input ldB compression point of - 4dBm and a sensitivity of - 70dBm when 10dB SNR for digital demodulation is required. The receiver is integrated in a reader transceiver chip and consumes 90mA from a 1.8V supply.
基金National Natural Science Foundation of China(No.50775034)
文摘The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the friction behavior of fibers,and the difference is largely responsible for the "stick-slip" motion of fibers which causes the drafting waves during drafting.In this paper,it's expected that when a high frequency undulating wave is imposed on the fiber strand in the drafting zone of roller system,the friction among fibers is dominated by the dynamic friction rather than the static friction,and thus the "stick-slip" motion will be eliminated.As a result,the fiber binding effect causing drafting waves can be significantly reduced.This hypothesis is verified by an experiment,and it can be applied in developing new spinning drafting device.
基金Project supported by the National Natural Science Foundation of China (Nos. 60473106, 60273060 and 60333010)the Ministry of Education of China (No. 20030335064)the Education Depart-ment of Zhejiang Province, China (No. G20030433)
文摘Video object segmentation is important for video surveillance, object tracking, video object recognition and video editing. An adaptive video segmentation algorithm based on hidden conditional random fields (HCRFs) is proposed, which models spatio-temporal constraints of video sequence. In order to improve the segmentation quality, the weights of spatio-temporal con- straints are adaptively updated by on-line learning for HCRFs. Shadows are the factors affecting segmentation quality. To separate foreground objects from the shadows they cast, linear transform for Gaussian distribution of the background is adopted to model the shadow. The experimental results demonstrated that the error ratio of our algorithm is reduced by 23% and 19% respectively, compared with the Gaussian mixture model (GMM) and spatio-temporal Markov random fields (MRFs).
文摘Headphones with an integrated active noise cancellation system have been increasingly introduced to the consumer market in recent years. When exposing the human ear to active noise sources in this striking distance, the ensuring of a safe sound pressure level is vital. In feedback systems, this is coupled with the stability of the closed control loop; stable controller design is thus essential. However, changes in the control path during run-time can cause the stable control system to become unstable, resulting in an overdrive of the speakers in the headphones. This paper proposes a method, which enables the real-time analysis of the current system state and if necessary stabilizes the closed loop while maintaining the active noise reduction. This is achieved by estimating and evaluating the open loop behavior with an adaptive filter and subsequently limiting the controller gain in respect to the stability margin.
基金Supported by the grant of Ministry of Science and Technology of the People' s Republic of China(2008ZX10002-25)National Natural Science Foundation of China(81070359)
文摘Objective:Percutaneous radiofrequency ablation(PRFA) is known to be as effective as hepatectomy for small hepatocellular carcinoma(HCC) in the long-term.We wished to ascertain how it is for recurrent small HCC.Methods:From January 2009 to November 2011,a series of sixty-one patients were included in the study according to the criteria:each patient had one recurrent HCC,less than 5 cm in diameter.Twenty-six of the 61 patients were treated with PRFA and the other 35 were treated with repeat hepatectomy.Results:The interval from first surgery to recurrent for repeat hepatectomy and PRFA groups were(1,239.60±1,017.00) d and(903.42±975.11) d respectively(P=0.066).The tumor-free time after repeat hepatectomy and PRFA were(310.23±159.50) d and(278.27±123.29) d respectively(P=0.584).Size of tumor in repeat hepatectomy and PRFA were(7.34±3.16) cm^2 and(5.59±3.40) cm^2(P=0.215),the total expenditure for each patient of the two groups were(26,150.66±7,923.60) yuan and(21,135.00±1,156.76) yuan(RMB),and the time of hospitalization for each of the two groups were(15.29±4.28) d and(7.46±2.20) d(P<0.001).Conclusion:PRFA is proved to be as effective as repeat hepatectomy in the treatment of recurrent small HCC,and superior to repeat hepatectomy as it is less invasive.
