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L波段探空系统高空风平滑计算方法探讨 被引量:26
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作者 王缅 李伟 +6 位作者 陈永清 赵培涛 郭启云 张宇 胡姮 郭月红 刘琳 《气象》 CSCD 北大核心 2011年第1期85-91,共7页
在分析现行业务L波段探空系统测风原理的基础上,提出改进高空测风数据的平滑计算方法。首先比较了业务分钟风与滑动平均风两种高空测风数据的平滑计算方法,并与GPS RS92测风数据进行了对比分析和批统计处理,特别是对业务L波段雷达在1-21... 在分析现行业务L波段探空系统测风原理的基础上,提出改进高空测风数据的平滑计算方法。首先比较了业务分钟风与滑动平均风两种高空测风数据的平滑计算方法,并与GPS RS92测风数据进行了对比分析和批统计处理,特别是对业务L波段雷达在1-21、22-42和43分钟及以后采取不同的时间间隔计算风的规定给出了分时段以及低仰角、远距离和小风速的统计分析。结果显示,滑动平均法在选取合适的滑动平均窗口的条件下,其计算的高空风与GPS RS92测风结果一致性更好且动态误差小。建议未来改进业务L波段探空系统的高空风平滑计算方法时,采用窗口为1分钟的滑动平均方式或者前20分钟采用30秒,以后采用1分钟的分段滑动平均方法。 展开更多
关键词 L波段 探空系统 高空风 平滑计算方法
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基于最优平滑系数三次指数平滑法的转速预测 被引量:14
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作者 张嘉望 郭军献 李福松 《探测与控制学报》 CSCD 北大核心 2015年第5期43-46,共4页
针对基于传统三次指数平滑法转速预测精度较低的问题,提出了基于最优平滑系数三次指数平滑法的转速预测方法。该方法根据已知的转速序列曲线,对平滑系数在其取值范围内进行搜索寻优,以预测转速的均方误差作为寻优目标函数,根据已知转速... 针对基于传统三次指数平滑法转速预测精度较低的问题,提出了基于最优平滑系数三次指数平滑法的转速预测方法。该方法根据已知的转速序列曲线,对平滑系数在其取值范围内进行搜索寻优,以预测转速的均方误差作为寻优目标函数,根据已知转速曲线的不同变化趋势,分段寻优并拟合得到目标函数与平滑系数间的函数关系,进而得到各段局部最优平滑系数,对局部最优平滑系数求和取平均值作为全段转速曲线的最优平滑系数,将最优平滑系数应用于工程,得到基于最优平滑系数的转速预测结果。验证结果表明,基于最优平滑系数三次指数平滑法的转速预测均方误差σ=0.048 6,且算法可以实现快速响应,能够满足工程要求。 展开更多
关键词 转速预测 三次指数平滑 计算最优平滑系数
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CSNS漂移管直线加速器隧道高精度准直方法及精度分析
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作者 马娜 柯志勇 +1 位作者 何振强 李波 《核技术》 CAS CSCD 北大核心 2018年第11期33-37,共5页
中国散裂中子源(China Spallation Neutron Source, CSNS)漂移管加速器(Drift Tube Linac, DTL)是CSNS直线加速器段的末端,其准直精度直接关系到直线加速器的最终性能。由于其长度长、腔体和腔内漂移管数量多,准直精度要求高,因此准直... 中国散裂中子源(China Spallation Neutron Source, CSNS)漂移管加速器(Drift Tube Linac, DTL)是CSNS直线加速器段的末端,其准直精度直接关系到直线加速器的最终性能。由于其长度长、腔体和腔内漂移管数量多,准直精度要求高,因此准直难度极大。针对该问题,通过外符合全面测量对漂移管预准直后的精度进行检核,可知漂移管中心孔和端面的测量值在DTL腔的预准直精度达到±0.035mm;采用大跨度、全覆盖的全面测量方法及平差在CSNS中的应用,实现直线隧道±0.03 mm和环隧道±0.04 mm的相对测量精度。提出了基于加速器准直的平滑计算及调整方法,实现DTL腔间的平滑调整,获得腔体±0.08 mm的隧道相对准直精度,漂移管±0.03 mm的腔内相对准直精度。 展开更多
关键词 DTL全面测量 平滑计算 相对位置精度
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Circular smooth muscle contributes to esophageal shortening during peristalsis 被引量:7
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作者 Anil K Vegesna Keng-Yu Chuang +5 位作者 Ramashesai Besetty Steven J Phillips Alan S Braverman Mary F Barbe Michael R Ruggieri Larry S Miller 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第32期4317-4322,共6页
AIM:To study the angle between the circular smooth muscle(CSM) and longitudinal smooth muscle(LSM) fibers in the distal esophagus.METHODS:In order to identify possible mechanisms for greater shortening in the distal c... AIM:To study the angle between the circular smooth muscle(CSM) and longitudinal smooth muscle(LSM) fibers in the distal esophagus.METHODS:In order to identify possible mechanisms for greater shortening in the distal compared to proximal esophagus during peristalsis,the angles between the LSM and CSM layers were measured in 9 cadavers.The outer longitudinal layer of the muscularis propria was exposed after stripping the outer serosa.The inner circular layer of the muscularis propria was then revealed after dissection of the esophageal mucosa and the underlying muscularis mucosa.Photographs of each specimen were taken with half of the open esophagus folded back showing both the outer longitudinal and inner circular muscle layers.Angles were measured every one cm for 10 cm proximal to the squamocolumnar junction(SCJ) by two independent investigators.Two human esophagi were obtained from organ transplant donors and the angles between the circular and longitudinal smooth muscle layers were measured using micro-computed tomography(micro CT) and Image J software.RESULTS:All data are presented as mean ± SE.The CSM to LSM angle at the SCJ and 1 cm proximal to SCJ on the autopsy specimens was 69.3 ± 4.62 degrees vs 74.9 ± 3.09 degrees,P = 0.32.The CSM to LSM angle at SCJ were statistically significantly lower than at 2,3,4 and 5 cm proximal to the SCJ,69.3 ± 4.62 degrees vs 82.58 ± 1.34 degrees,84.04 ± 1.64 degrees,84.87 ± 1.04 degrees and 83.72 ± 1.42 degrees,P = 0.013,P = 0.008,P = 0.004,P = 0.009 respectively.The CSM to LSM angle at SCJ was also statistically significantly lower than the angles at 6,7 and 8 cm proximal to the SCJ,69.3 ± 4.62 degrees vs 80.18 ± 2.09 degrees,81.81 ± 1.75 degrees and 80.96 ± 2.04 degrees,P = 0.05,P = 0.02,P = 0.03 respectively.The CSM to LSM angle at 1 cm proximal to SCJ was statistically significantly lower than at 3,4 and 5 cm proximal to the SCJ,74.94 ± 3.09 degrees vs 84.04 ± 1.64 degrees,84.87 ± 1.04 degrees and 83.72 ± 1.42 degrees,P = 0.019,P = 0.008,P = 0.02 respectively.At 10 cm above SCJ the angle was 80.06 ± 2.13 degrees which is close to being perpendicular but less than 90 degrees.The CSM to LSM angles measured on virtual dissection of the esophagus and the stomach on micro CT at the SCJ and 1 cm proximal to the SCJ were 48.39 ± 0.72 degrees and 50.81 ± 1.59 degrees.Rather than the angle of the CSM and LSM being perpendicular in the esophagus we found an acute angulation between these two muscle groups throughout the lower 10 cm of the esophagus.CONCLUSION:The oblique angulation of the CSM may contribute to the significantly greater shortening of distal esophagus when compared to the mid and proximal esophagus during peristalsis. 展开更多
关键词 Esophageal shortening Gastroesophageal junction Circular smooth muscle Gastroesophageal reflux disease Esophageal contraction
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A new method to calculate lateral force acting on stabilizing piles based on multi-wedge translation mechanism 被引量:2
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作者 罗渝 许强 +3 位作者 何思明 李新坡 何尽川 吴永 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期654-661,共8页
A new method based on the multi-wedge translation mechanism is presented to calculate the lateral force acting on the stabilizing piles. At first, there is no assumption for the shape of potential sliding surface, it ... A new method based on the multi-wedge translation mechanism is presented to calculate the lateral force acting on the stabilizing piles. At first, there is no assumption for the shape of potential sliding surface, it is just considered that the potential sliding surface is a composite of a number of straight lines. And then, the potential sliding mass is divided into a number of triangular wedges take with these straight lines as its base. The kinematic theorem of limit analysis is adopted to calculate the rate of external work and the rate of energy dissipation for each triangular wedge, respectively. Furthermore, the multivariate functions are established to calculate the lateral force acting on the stabilizing piles. The lateral force and the corresponding potential sliding surfaces can be obtained by an optimizational technique. At last, an example is taken to illustrate the method. The effect of soil strength parameters, slope angle and pile roughness on the lateral force and the corresponding potential sliding surface are analyzed.The result are compared with those obtained using other methods. 展开更多
关键词 PILE sliding surface limit analysis multi-wedge mechanism
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Adaptive preprocessing algorithms of corneal topography in polar coordinate system 被引量:1
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作者 郭雁文 《Journal of Central South University》 SCIE EI CAS 2014年第12期4571-4576,共6页
New adaptive preprocessing algorithms based on the polar coordinate system were put forward to get high-precision corneal topography calculation results. Adaptive locating algorithms of concentric circle center were c... New adaptive preprocessing algorithms based on the polar coordinate system were put forward to get high-precision corneal topography calculation results. Adaptive locating algorithms of concentric circle center were created to accurately capture the circle center of original Placido-based image, expand the image into matrix centered around the circle center, and convert the matrix into the polar coordinate system with the circle center as pole. Adaptive image smoothing treatment was followed and the characteristics of useful circles were extracted via horizontal edge detection, based on useful circles presenting approximate horizontal lines while noise signals presenting vertical lines or different angles. Effective combination of different operators of morphology were designed to remedy data loss caused by noise disturbances, get complete image about circle edge detection to satisfy the requests of precise calculation on follow-up parameters. The experimental data show that the algorithms meet the requirements of practical detection with characteristics of less data loss, higher data accuracy and easier availability. 展开更多
关键词 corneal topography Placido disk polar coordinate self-adoption preprocessing algorithms
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Schedule for Garment Assembly Line Based on Genetic Algorithm
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作者 王东云 吴俊 刘淑英 《Journal of Donghua University(English Edition)》 EI CAS 2003年第3期104-107,共4页
A new way to solve the scheduling problem ofgarment assembly line based on genetic algorithmwas proposed. The chromosome was decoded usingtask precedence relation and after the operation ofreproduction, crossover and ... A new way to solve the scheduling problem ofgarment assembly line based on genetic algorithmwas proposed. The chromosome was decoded usingtask precedence relation and after the operation ofreproduction, crossover and mutation, the globaloptimal result can be obtained. Fitness function wasrepresented by smoothness Index ( SI ). Thesimulation shows that the method proposed in thispaper is better than the conventional way and theoptimized solution can be got in this way. 展开更多
关键词 Garment sewing Assembly Line SCHEDULE Genetic Algorithm Smoothness Index
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A case of hepatic angiomyolipoma difficult to distinguish from hepatocellular carcinoma 被引量:8
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作者 Masahiro Takahara Yasuhiro Miyake +6 位作者 Kazuyuki Matsumoto Daisuke Kawai Eisuke Kaji Tatsuya Toyokawa Morihito Nakatsu Masaharu Ando Mamoru Hirohata 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第23期2930-2932,共3页
We report a case of hepatic angiomyolipoma with uncommon clinical features. A 56-year-old man presented with a hepatic tumor in the caudate lobe. The tumor was hypoechoic on ultrasonography, showed early-phase hyperat... We report a case of hepatic angiomyolipoma with uncommon clinical features. A 56-year-old man presented with a hepatic tumor in the caudate lobe. The tumor was hypoechoic on ultrasonography, showed early-phase hyperattenuation on enhanced computed tomography and did not absorb iron on superparamagnetic iron oxide-enhanced magnetic resonance imaging. Hepatocellular carcinoma was highly suspected, and the patient underwent hepatic resection. Histologically, the tumor was mainly composed of smooth muscle cells and contained small amounts of adipose cells and blood vessels. On immunohistochemical staining, the smooth muscle cells were positive for a melanocytic cell-specific monoclonal antibody. In cases with uncommon features of angiomyolipoma, it is quite difficult to distinguish angiomyolipoma from hepatocellular carcinoma. 展开更多
关键词 Adipose cell Hepatic angiomyolipoma Hepatocellular carcinoma HMB-45 Smooth muscle cell
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Excel预测衢州未来经济社会与交通需求发展规律
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作者 仝绪站 王婷静 +1 位作者 李炜 钱香怡 《四川建筑》 2021年第4期7-9,共3页
交通建设与未来经济发展密切相关。一方面,交通运输业的发展增大了经济活动的范围;而另一方面,经济发展又完善了交通运输网络的建设。文章利用Excel软件对衢州市1949~2018年间生产总值、第三产业经济总值、货物运输量、旅客运送量、第... 交通建设与未来经济发展密切相关。一方面,交通运输业的发展增大了经济活动的范围;而另一方面,经济发展又完善了交通运输网络的建设。文章利用Excel软件对衢州市1949~2018年间生产总值、第三产业经济总值、货物运输量、旅客运送量、第三产业总值占比、第三产业从业人员数、第三产业增加值、公路里程、铁路总运营里程进行分析,并利用FORECAST.ETS函数对未来经济、交通发展趋势进行计算并作出相应预测。分析结果显示,交通发展对于衢州市经济有较明显的促进作用,且当2009年货运量大幅上升、客运量大幅下降时,经济总值并没有受到明显影响。未来衢州应继续发展交通建设,并调整交通结构建设,建议尝试将交通运输发展重心偏向客运方面。 展开更多
关键词 EXCEL 计算指数平滑算法 未来经济与交通需求 交通结构调整
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ESTIMATION ON SEMIVARYING COEFFICIENT MODELS WITH DIFFERENT DEGREES OF SMOOTHNESS
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作者 Riquan ZHANG Jingyan FENG +1 位作者 Kaichun WEN Jianhua DING 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2009年第3期469-482,共14页
Semivarying coefficient models are frequently used in statistical models.In this paper,under the condition that the coefficient functions possess different degrees of smoothness,a two-stepmethod is proposed.In the cas... Semivarying coefficient models are frequently used in statistical models.In this paper,under the condition that the coefficient functions possess different degrees of smoothness,a two-stepmethod is proposed.In the case,one-step method for the smoother coefficient functions cannot beoptimal.This drawback can be repaired by using the two-step estimation procedure.The asymptoticmean-squared error for the two-step procedure is obtained and is shown to achieve the optimal rate ofconvergence.A few simulation studies are conducted to evaluate the proposed estimation methods. 展开更多
关键词 Local polynomial regression one-step estimation optimal rate of convergence semi-varying coefficient model two-step estimation.
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