Based on the stability theory, numerical simulations and theoretical calculations are performed for a projectile with wrap-around fins. Its stability is analyzed and the flow field is simulated with computational flui...Based on the stability theory, numerical simulations and theoretical calculations are performed for a projectile with wrap-around fins. Its stability is analyzed and the flow field is simulated with computational fluid dynamics method. Consequently, the pitching moment coefficient of the projectile is further investigated under the conditions of Mach number ranging from 0.3 to 0.8, attack angle from 0 to 8° and yaw angle from 0 to 4°. A trajectory equation is established and its trajectory characteristics are also explored. All the results of theoretical analysis, numerical simulation and trajectory equation agree well with each other, which indicates the projectile is flying steadily at the given conditions. These results provide an effective way for judging the stability of the projectile with wrap-around fins.展开更多
The purpose of the present article is to introduce a class of mixed two- and three-level extended designs obtained by adding some new runs to an existing mixed two- and three-level design. A formulation of wrap-around...The purpose of the present article is to introduce a class of mixed two- and three-level extended designs obtained by adding some new runs to an existing mixed two- and three-level design. A formulation of wrap-around L2-discrepancy for the extended designs is developed. As a benchmark of obtaining （nearly） uniform asymmetrical extended designs, a lower bound to the wrap-around L2- discrepancy for our proposed designs is established. Thorough numerical results are displayed, which provide further corroboration to the derived theoretical results.展开更多
The objective of this paper is to study the issue of uniformity on three-level U-type designs in terms of the wrap-around L2-discrepancy.Based on the known formula,we present a new lower bound of wrap-around L2-discre...The objective of this paper is to study the issue of uniformity on three-level U-type designs in terms of the wrap-around L2-discrepancy.Based on the known formula,we present a new lower bound of wrap-around L2-discrepancy for three-level U-type designs and compare it with those existing ones through figures,numerical simulation and illustrative examples.展开更多
How to obtain an effective design is a major concern of scientific research. This topic always involves high-dimensional inputs with limited resources. The foldover is a quick and useful technique in construction of f...How to obtain an effective design is a major concern of scientific research. This topic always involves high-dimensional inputs with limited resources. The foldover is a quick and useful technique in construction of fractional designs, which typically releases aliased factors or interactions.This paper takes the wrap-around L_2-discrepancy as the optimality measure to assess the optimal three-level combined designs. New and efficient analytical expressions and lower bounds of the wraparound L_2-discrepancy for three-level combined designs are obtained. The new lower bound is useful and sharper than the existing lower bound. Using the new analytical expression and lower bound as the benchmarks, the authors may implement an effective algorithm for constructing optimal three-level combined designs.展开更多
目的评价改良法甲皮瓣移植再造拇指术后再造拇指及供足的功能改变。方法对2003年1月-2007年10月接受改良甲皮瓣移植再造拇指的65例患者进行随访。男54例,女11例;年龄15～46岁,平均33岁。术前拇指缺损程度根据三类六区分类法,皮肤脱...目的评价改良法甲皮瓣移植再造拇指术后再造拇指及供足的功能改变。方法对2003年1月-2007年10月接受改良甲皮瓣移植再造拇指的65例患者进行随访。男54例,女11例;年龄15～46岁,平均33岁。术前拇指缺损程度根据三类六区分类法,皮肤脱套伤和晚期ⅠB类缺失12例,Ⅱ类缺失44例,ⅢA类缺失9例。术后观测再造拇指及供足改变;并对最后获随访的20例患者供足进行足功能指数-5分口述评分量表(foot function index-verbal rating scales,FFI-5pt)、美国足踝外科学会(AOFAS)趾-跖趾-趾间关节评分,同时采用F-Scan动态足底测压系统测定供足步态参数及足底压力的动态分布情况。结果65例均获随访,随访时间6～60个月,平均22个月。再造拇指外形与健侧相似;两点辨别觉为(9.7±2.8)mm,与健侧(4.2±1.1)mm比较差异有统计学意义(P<0.05)。63例供趾保留了全长或大部分长度,2例自近节趾骨头水平缺失;跖侧保留皮条宽(24.5±3.7)mm,覆盖趾底负重区域,其两点辨别觉(9.0±2.6)mm,与健侧(8.1±1.9)mm比较差异无统计学意义(P>0.05)。最后获随访的20例患者供足FFI-5pt评分中,疼痛指数为5.6±4.5,行动障碍指数为1.2±2.7,足功能指数为3.2±2.9;AOFAS评分中,疼痛评分为(34.0±5.0)分,功能评分为(38.7±4.2)分,排列评分为(15.0±0)分,总评分为(87.7±7.4)分。供足与健侧足相比,步态周期内支撑相持续时间以及各时相占整个步态周期的百分比差异均无统计学意义(P>0.05),全足所承受的峰压力及压力-时间积分亦无统计学意义(P>0.05)。供足趾峰压力显著小于健侧趾(P<0.05),峰压强差异无统计学意义(P>0.05);双侧足底其他6个解剖部位的峰压力及峰压强比较差异均无统计学意义(P>0.05)。结论改良游离甲皮瓣移植再造拇指,在不降低再造拇指质量的同时,保护了供足的功能。展开更多
为解决Curvelet图像去噪所产生的"环绕"效应以及非局部TV模型去噪过度平滑而无法保持细小纹理的问题,本文提出了一种基于Curvelet变换与非局部TV模型相结合的图像去噪方法(Curvelet and Non-Local TV,CNL-TV)。该方法首先对...为解决Curvelet图像去噪所产生的"环绕"效应以及非局部TV模型去噪过度平滑而无法保持细小纹理的问题,本文提出了一种基于Curvelet变换与非局部TV模型相结合的图像去噪方法(Curvelet and Non-Local TV,CNL-TV)。该方法首先对含噪图像进行Curvelet变换,将其分解成不同尺度的图像;其次根据每层图像的特性,选择合适的非局部TV模型参数分别进行处理;最后将处理后的每层图像融合。实验结果表明,该算法不仅能够有效地减少噪声,消除Curvelet去噪产生的"环绕"效应,而且最大程度地保持了图像中的细小纹理成分。通过比较不同方法所得结果的峰值信噪比,验证了算法的有效性。展开更多
基金the National Natural Science Foundation of China (10572026)
文摘Based on the stability theory, numerical simulations and theoretical calculations are performed for a projectile with wrap-around fins. Its stability is analyzed and the flow field is simulated with computational fluid dynamics method. Consequently, the pitching moment coefficient of the projectile is further investigated under the conditions of Mach number ranging from 0.3 to 0.8, attack angle from 0 to 8° and yaw angle from 0 to 4°. A trajectory equation is established and its trajectory characteristics are also explored. All the results of theoretical analysis, numerical simulation and trajectory equation agree well with each other, which indicates the projectile is flying steadily at the given conditions. These results provide an effective way for judging the stability of the projectile with wrap-around fins.
基金supported by the National Natural Science Foundation of China under Grant Nos.11271147,11471135,11471136support of Excellent Doctoral Dissertation to Cultivate Project of Central China Normal University under Grant No.2017YBZZ057
文摘The purpose of the present article is to introduce a class of mixed two- and three-level extended designs obtained by adding some new runs to an existing mixed two- and three-level design. A formulation of wrap-around L2-discrepancy for the extended designs is developed. As a benchmark of obtaining （nearly） uniform asymmetrical extended designs, a lower bound to the wrap-around L2- discrepancy for our proposed designs is established. Thorough numerical results are displayed, which provide further corroboration to the derived theoretical results.
基金Supported in part by the National Natural Science Foundation of China(Nos.11871237,11801576,11271147,11401596)the Fundamental Research Funds for the Central Universities(South-Central University for Nationalities(Nos.CZQ18017,CZQ19010))
文摘The objective of this paper is to study the issue of uniformity on three-level U-type designs in terms of the wrap-around L2-discrepancy.Based on the known formula,we present a new lower bound of wrap-around L2-discrepancy for three-level U-type designs and compare it with those existing ones through figures,numerical simulation and illustrative examples.
基金supported by the National Natural Science Foundation of China under Grant Nos.11271147,11471135,11471136the UIC Grant R201409+1 种基金the Zhuhai Premier Discipline Grantthe Self-Determined Research Funds of CCNU from the Colleges Basic Research and Operation of MOE under Grant Nos.CCNU14A05041,CCNU16A02012
文摘How to obtain an effective design is a major concern of scientific research. This topic always involves high-dimensional inputs with limited resources. The foldover is a quick and useful technique in construction of fractional designs, which typically releases aliased factors or interactions.This paper takes the wrap-around L_2-discrepancy as the optimality measure to assess the optimal three-level combined designs. New and efficient analytical expressions and lower bounds of the wraparound L_2-discrepancy for three-level combined designs are obtained. The new lower bound is useful and sharper than the existing lower bound. Using the new analytical expression and lower bound as the benchmarks, the authors may implement an effective algorithm for constructing optimal three-level combined designs.
文摘目的评价改良法甲皮瓣移植再造拇指术后再造拇指及供足的功能改变。方法对2003年1月-2007年10月接受改良甲皮瓣移植再造拇指的65例患者进行随访。男54例,女11例;年龄15～46岁,平均33岁。术前拇指缺损程度根据三类六区分类法,皮肤脱套伤和晚期ⅠB类缺失12例,Ⅱ类缺失44例,ⅢA类缺失9例。术后观测再造拇指及供足改变;并对最后获随访的20例患者供足进行足功能指数-5分口述评分量表(foot function index-verbal rating scales,FFI-5pt)、美国足踝外科学会(AOFAS)趾-跖趾-趾间关节评分,同时采用F-Scan动态足底测压系统测定供足步态参数及足底压力的动态分布情况。结果65例均获随访,随访时间6～60个月,平均22个月。再造拇指外形与健侧相似;两点辨别觉为(9.7±2.8)mm,与健侧(4.2±1.1)mm比较差异有统计学意义(P<0.05)。63例供趾保留了全长或大部分长度,2例自近节趾骨头水平缺失;跖侧保留皮条宽(24.5±3.7)mm,覆盖趾底负重区域,其两点辨别觉(9.0±2.6)mm,与健侧(8.1±1.9)mm比较差异无统计学意义(P>0.05)。最后获随访的20例患者供足FFI-5pt评分中,疼痛指数为5.6±4.5,行动障碍指数为1.2±2.7,足功能指数为3.2±2.9;AOFAS评分中,疼痛评分为(34.0±5.0)分,功能评分为(38.7±4.2)分,排列评分为(15.0±0)分,总评分为(87.7±7.4)分。供足与健侧足相比,步态周期内支撑相持续时间以及各时相占整个步态周期的百分比差异均无统计学意义(P>0.05),全足所承受的峰压力及压力-时间积分亦无统计学意义(P>0.05)。供足趾峰压力显著小于健侧趾(P<0.05),峰压强差异无统计学意义(P>0.05);双侧足底其他6个解剖部位的峰压力及峰压强比较差异均无统计学意义(P>0.05)。结论改良游离甲皮瓣移植再造拇指,在不降低再造拇指质量的同时,保护了供足的功能。
文摘为解决Curvelet图像去噪所产生的"环绕"效应以及非局部TV模型去噪过度平滑而无法保持细小纹理的问题,本文提出了一种基于Curvelet变换与非局部TV模型相结合的图像去噪方法(Curvelet and Non-Local TV,CNL-TV)。该方法首先对含噪图像进行Curvelet变换,将其分解成不同尺度的图像;其次根据每层图像的特性,选择合适的非局部TV模型参数分别进行处理;最后将处理后的每层图像融合。实验结果表明,该算法不仅能够有效地减少噪声,消除Curvelet去噪产生的"环绕"效应,而且最大程度地保持了图像中的细小纹理成分。通过比较不同方法所得结果的峰值信噪比,验证了算法的有效性。
