An improved linear-time retiming algorithm is proposed to incrementally optimize the clock period, espe cially considering the influence of the in-out degree of the critical combinational elements. Firslly, the critic...An improved linear-time retiming algorithm is proposed to incrementally optimize the clock period, espe cially considering the influence of the in-out degree of the critical combinational elements. Firslly, the critical elements are selected from all the critical combinational elements to retime. Secondly, for the nodes that cannot be performed with such retiming, register sharing is implemented while the path delay is kept unchanged. The incremental algorithm can be applied with the technology mapping to minimize the critical path delay and obtain fewer registers in the re- timed circuit with the near-optimal clock period. Compared with Singh＇s incremental algorithm, experiments show that the proposed algorithm can reduce the flip-flop count by 11% and look-up table （LUT） count by 5% while improv- ing the minimum clock period by 6%. The runtime is also reduced by 9% of the design flow.展开更多
To evaluate the effects of maternal pre-pregnancy body mass index （pre-BMI） and gestational weight gain （GWG） on neonatal birth weight （NBW） in the population of Chinese healthy pregnant women, attempting to gui...To evaluate the effects of maternal pre-pregnancy body mass index （pre-BMI） and gestational weight gain （GWG） on neonatal birth weight （NBW） in the population of Chinese healthy pregnant women, attempting to guide weight control in pregnancy. A retrospective cohort study of 3772 Chinese women was conducted. The population was stratified by maternal pre-BMI categories as underweight （〈18.5 kg/m2）, normal weight （18.5-23.9 kg/m2）, overweight （24.0-27.9 kg/m2）, and obesity （〉28.0 kg/m2）. The NBW differences were tested among the four groups, and then deeper associations among maternal pre-BMI, GWG, and NBW were investigated by multivariate analysis. NBW increased significantly with the increase of maternal pre-BMI level （P〈0.05）, except overweight to obesity （P〉0.05）. The multivariate analysis showed that both pre-BMI and GWG were positively correlated with NBW （P〈0.05）. Compared with normal pre-BMI, underweight predicted an increased odds ratio of small-for-gestational-age （SGA） and decreased odds ratio for macrosomia and large-for-gestational-age （LGA）, and the results were opposite for overweight. With the increase of GWG, the risk of SGA decreased and the risks of macrosomia and LGA increased. In addition, in different pre-BMI categories, the effects of weight gain in the first trimester on NBW were different （P〈0.05）. NBW is positively affected by both maternal pre-BMI and GWG, extreme pre-BMI and GWG are both associated with increased risks of abnormal birth weight, and maternal pre-BMI may modify the effect of weight gain in each trimester on NBW. A valid GWG guideline for Chinese women is an urgent requirement, whereas existing recommendations seem to be not very suitable for the Chinese.展开更多
基金Supported by Major National Scientific Research Plan (No. 2011CB933202)
文摘An improved linear-time retiming algorithm is proposed to incrementally optimize the clock period, espe cially considering the influence of the in-out degree of the critical combinational elements. Firslly, the critical elements are selected from all the critical combinational elements to retime. Secondly, for the nodes that cannot be performed with such retiming, register sharing is implemented while the path delay is kept unchanged. The incremental algorithm can be applied with the technology mapping to minimize the critical path delay and obtain fewer registers in the re- timed circuit with the near-optimal clock period. Compared with Singh＇s incremental algorithm, experiments show that the proposed algorithm can reduce the flip-flop count by 11% and look-up table （LUT） count by 5% while improv- ing the minimum clock period by 6%. The runtime is also reduced by 9% of the design flow.
基金Project supported by the National Natural Science Foundation of China(Nos.81370725 and 81370726)the Natural Science Foundation of Zhejiang Province(No.LQ14H040004)the Key Discipline of Obstetrics of Zhejiang Province,China
文摘To evaluate the effects of maternal pre-pregnancy body mass index （pre-BMI） and gestational weight gain （GWG） on neonatal birth weight （NBW） in the population of Chinese healthy pregnant women, attempting to guide weight control in pregnancy. A retrospective cohort study of 3772 Chinese women was conducted. The population was stratified by maternal pre-BMI categories as underweight （〈18.5 kg/m2）, normal weight （18.5-23.9 kg/m2）, overweight （24.0-27.9 kg/m2）, and obesity （〉28.0 kg/m2）. The NBW differences were tested among the four groups, and then deeper associations among maternal pre-BMI, GWG, and NBW were investigated by multivariate analysis. NBW increased significantly with the increase of maternal pre-BMI level （P〈0.05）, except overweight to obesity （P〉0.05）. The multivariate analysis showed that both pre-BMI and GWG were positively correlated with NBW （P〈0.05）. Compared with normal pre-BMI, underweight predicted an increased odds ratio of small-for-gestational-age （SGA） and decreased odds ratio for macrosomia and large-for-gestational-age （LGA）, and the results were opposite for overweight. With the increase of GWG, the risk of SGA decreased and the risks of macrosomia and LGA increased. In addition, in different pre-BMI categories, the effects of weight gain in the first trimester on NBW were different （P〈0.05）. NBW is positively affected by both maternal pre-BMI and GWG, extreme pre-BMI and GWG are both associated with increased risks of abnormal birth weight, and maternal pre-BMI may modify the effect of weight gain in each trimester on NBW. A valid GWG guideline for Chinese women is an urgent requirement, whereas existing recommendations seem to be not very suitable for the Chinese.
