This paper makes an approach to the approximate optimum in structural design,which combines the global response surface（GRS） based multivariate adaptive regression splines（MARS） with Move-Limit strategy（MLS）.MAR...This paper makes an approach to the approximate optimum in structural design,which combines the global response surface（GRS） based multivariate adaptive regression splines（MARS） with Move-Limit strategy（MLS）.MARS is an adaptive regression process,which fits in with the multidimensional problems.It adopts a modified recursive partitioning strategy to simplify high-dimensional problems into smaller highly accurate models.MLS for moving and resizing the search sub-regions is employed in the space of design variables.The quality of the approximation functions and the convergence history of the optimization process are reflected in MLS.The disadvantages of the conventional response surface method（RSM） have been avoided,specifically,highly nonlinear high-dimensional problems.The GRS/MARS with MLS is applied to a high-dimensional test function and an engineering problem to demonstrate its feasibility and convergence,and compared with quadratic response surface（QRS） models in terms of computational efficiency and accuracy.展开更多
目的观察Airtraq喉镜用于颈椎手术合并困难气道患者气管插管的效果。方法选择2014年7月-2015年7月于我院择期行颈椎手术的患者80例,随机将其分为A组（Airtraq喉镜）和B组（普通喉镜）,每组40例。静脉麻醉诱导后,两组分别在Airtraq喉镜...目的观察Airtraq喉镜用于颈椎手术合并困难气道患者气管插管的效果。方法选择2014年7月-2015年7月于我院择期行颈椎手术的患者80例,随机将其分为A组（Airtraq喉镜）和B组（普通喉镜）,每组40例。静脉麻醉诱导后,两组分别在Airtraq喉镜、普通喉镜引导下经口行气管插管。记录两组患者麻醉诱导前、气管插管即刻和插管后1、2、3 min的平均动脉压（MAP）、心率（HR）及（BIS）值,以及两组喉镜下声门显露情况、插管时间、一次插管成功率和插管总成功率等。结果喉镜下声门显露A组患者均为Ⅰ级,B组患者有14例为Ⅰ级,12例为Ⅱ级,9例为Ⅲ级,5例为Ⅳ级。A组插管时间（10.5±6.2）s,明显短于B组的（75.3±4.1）s（P〈0.05）。A组插管即刻MAP、HR及BIS值均显著低于B组（P〈0.05）;插管后2、3 min MAP和HR均显著低于B组（P〈0.05）,BIS值差异无统计学意义（P〉0.05）。A组所有病例均未行喉部外压动作,B组行喉部外压动作8例,差异有统计学意义（P〈0.05）。A组总成功40例,均一次插管成功;B组总成功36例,其中一次插管成功34例,三次插管成功2例,4例因3次插管后仍未能显露声门,改用纤支镜完成插管,A组一次插管成功率和插管总成功率均明显高于B组（P〈0.05）。结论 Airtraq喉镜用于颈椎活动受限患者气管插管,视野清晰、暴露好,插管迅速,对患者血流动力学影响小,且成功率高、损伤小。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.50775084)the National Hightechnology Research and Development Program of China (Grant No.2006AA04Z121)
文摘This paper makes an approach to the approximate optimum in structural design,which combines the global response surface（GRS） based multivariate adaptive regression splines（MARS） with Move-Limit strategy（MLS）.MARS is an adaptive regression process,which fits in with the multidimensional problems.It adopts a modified recursive partitioning strategy to simplify high-dimensional problems into smaller highly accurate models.MLS for moving and resizing the search sub-regions is employed in the space of design variables.The quality of the approximation functions and the convergence history of the optimization process are reflected in MLS.The disadvantages of the conventional response surface method（RSM） have been avoided,specifically,highly nonlinear high-dimensional problems.The GRS/MARS with MLS is applied to a high-dimensional test function and an engineering problem to demonstrate its feasibility and convergence,and compared with quadratic response surface（QRS） models in terms of computational efficiency and accuracy.
文摘目的观察Airtraq喉镜用于颈椎手术合并困难气道患者气管插管的效果。方法选择2014年7月-2015年7月于我院择期行颈椎手术的患者80例,随机将其分为A组（Airtraq喉镜）和B组（普通喉镜）,每组40例。静脉麻醉诱导后,两组分别在Airtraq喉镜、普通喉镜引导下经口行气管插管。记录两组患者麻醉诱导前、气管插管即刻和插管后1、2、3 min的平均动脉压（MAP）、心率（HR）及（BIS）值,以及两组喉镜下声门显露情况、插管时间、一次插管成功率和插管总成功率等。结果喉镜下声门显露A组患者均为Ⅰ级,B组患者有14例为Ⅰ级,12例为Ⅱ级,9例为Ⅲ级,5例为Ⅳ级。A组插管时间（10.5±6.2）s,明显短于B组的（75.3±4.1）s（P〈0.05）。A组插管即刻MAP、HR及BIS值均显著低于B组（P〈0.05）;插管后2、3 min MAP和HR均显著低于B组（P〈0.05）,BIS值差异无统计学意义（P〉0.05）。A组所有病例均未行喉部外压动作,B组行喉部外压动作8例,差异有统计学意义（P〈0.05）。A组总成功40例,均一次插管成功;B组总成功36例,其中一次插管成功34例,三次插管成功2例,4例因3次插管后仍未能显露声门,改用纤支镜完成插管,A组一次插管成功率和插管总成功率均明显高于B组（P〈0.05）。结论 Airtraq喉镜用于颈椎活动受限患者气管插管,视野清晰、暴露好,插管迅速,对患者血流动力学影响小,且成功率高、损伤小。
