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Independent sampling and padding for Rayleigh-Sommerfeld diffraction based on scaled convolution approach
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作者 YANG Chen FU Xi-hong +1 位作者 FU Xin-peng BAYANHESHIG 《中国光学(中英文)》 北大核心 2026年第2期367-381,共15页
We propose a novel fast numerical calculation method for the Rayleigh-Sommerfeld diffraction integral,which is developed based on the existing scaled convolution method.This approach enables fast cal-culations for gen... We propose a novel fast numerical calculation method for the Rayleigh-Sommerfeld diffraction integral,which is developed based on the existing scaled convolution method.This approach enables fast cal-culations for general cases of off-axis scenarios where the sampling intervals and numbers of the input and observation planes are unequal.Additionally,it allows for arbitrary adjustment of the sampling interval of the impulse response function,facilitating a manual trade-off between computational load and accuracy.The er-rors associated with this method,which is equivalent to interpolation,primarily arise from the discontinuities of the sampling matrix of the impulse response function on its boundaries of periodic extension.To address this issue,we propose the concept of the padding function and its construction method,and evaluate its ef-fectiveness in enhancing computational accuracy.The feasibility of the proposed method is verified by nu-merical simulation and compared with the direct integration DI-method in a simplified scenario.It shows that the proposed method has good computational accuracy for the general case where the sampling interval of the input and observation plane is not equal under non-near-field diffraction,and when the diffraction distance is large,although the computational accuracy of the proposed method cannot exceed that of the DI-method,the computational amount can be significantly reduced with almost no effect on the computational accuracy.This method provides a general numerical calculation scheme of diffraction in the non-near field case for areas such as computational holography. 展开更多
关键词 Rayleigh-Sommerfeld diffraction scaled convolution padding function
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Effects of Different Padding on Air Quality in Broiler House and Growth Physiological Index of Broilers 被引量:1
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作者 刘雪兰 张燕 +5 位作者 阎佩佩 井庆川 魏祥法 刘瑞亭 石天虹 武彬 《Agricultural Science & Technology》 CAS 2015年第12期2764-2769,共6页
[Objective] This study aimed to investigate the effects of different padding on ammonia concentration in broiler house and growth performance and blood indi- cators of broilers. [Method] A total of 480 one-day-old 817... [Objective] This study aimed to investigate the effects of different padding on ammonia concentration in broiler house and growth performance and blood indi- cators of broilers. [Method] A total of 480 one-day-old 817 broilers were selected. They were randomly divided into four groups with different paddings, and each group was in triplicate. The weights of broilers and feed were weighed weekly. The growth performance of broilers was determined. On day 30, the ammonia concentra- tions in broiler houses were determined. On day 35, 6 broilers were randomly se- lected from each group, and their vein blood was sampled. In the sampled vein blood, the concentrations of ammonia, glucose, globulin, serum total protein and urea nitrogen were determined. [Result] There were significant differences in ammo- nia concentration among broiler houses laid with different paddings (P〈0.05). The ammonia concentration in group 1 was significantly lower than those in group 3 and group 4 (P〈0.05). No significant difference was found in ammonia concentrations in broiler houses between group 2 and group 3 (P〉0.05). The ammonia concentration in group 4 was significantly higher than those in group1, group 2 and group 3 (,0〈 0.05). There were also significant differences in blood indicators among different groups (P〈0.05). The blood ammonia, blood glucose and serum urea nitrogen con- centrations in group 1 were significantly lower than those in other groups (P〈0.05), the serum total protein concentration was significantly higher than those in group 3 and group 4 (P〈0.05), and the serum globulin concentration was significantly higher than those in group 2, group 3 and group 4 (P〈0.05). Significant differences were observed in feed intake, body weight gain and slaughter weight between different groups (P〈0.05), but there were no significant differences in feed to grain ratio (P〉 0.05). [Conclusion] Under the experimental conditions, the padding of Chinese medicine residue showed better effect on reducing ammonia concentration in broiler house, which was conducive to play of production potential of broilers. 展开更多
关键词 Chinese medicine residue padding Ammonia concentration Production performance Blood indicators
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CME指导下的PADDING算法
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作者 舒辉 杨磊 王丽华 《信息工程大学学报》 2002年第4期35-39,共5页
PADDING是一种提高程序中循环Cache命中率的有效方法,其有效性的关键在于选取合适的PADDING大小以尽可能地消除循环中数组引用之间的Cache冲突。本文从CME理论出发,根据循环中数组引用重用向量的不同,建立对应的CME模型并对其进行分析,... PADDING是一种提高程序中循环Cache命中率的有效方法,其有效性的关键在于选取合适的PADDING大小以尽可能地消除循环中数组引用之间的Cache冲突。本文从CME理论出发,根据循环中数组引用重用向量的不同,建立对应的CME模型并对其进行分析,给出两种不同的计算PADDING大小的算法。我们运用这两种算法对BenchmarkSPEC95中部分测试程序进行Cache优化试验,取得了较好的效果。 展开更多
关键词 padding算法 CME CACHE命中率 程序设计 循环变换 数组变换 Cache冲突
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Application of insulation padding in a heavy turbine guide vane casting
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作者 Jin-wu Kang Qing-xian Ma +4 位作者 Chi Zhang Pei-chao Zhou Zhong-ren Liu Zu-liang Li Hao Zhang 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2017年第5期495-500,共6页
To replace metal padding by insulation padding for castings can save the melt and reduce cleaning work of castings. The design of insulation padding was investigated. The equation of the modulus extension factor for i... To replace metal padding by insulation padding for castings can save the melt and reduce cleaning work of castings. The design of insulation padding was investigated. The equation of the modulus extension factor for insulation padding and the ratio of its thickness over the modulus of a casting were improved to deter- mine the thickness of insulation padding. The insulation padding was designed for a turbine guide vane casting weighing 3.5 t. A sound casting was obtained with 750 kg steel saved. On the other side, the cast- ing obviously expanded at the interface with the insulation padding, which is perhaps the reason that the use of insulation padding has been suspended for many years. To avoid the expansion of insulation pad- ding, a shielding layer made of a kind of material of good fire resistance was adopted to prevent the insula- tion layer from touching the melt. The shielding layer serves as a cushion of heat and expansion during so- lidification process so as to resist the expansion of castings and guarantee the feeding effect at the same time. Furthermore, insulation padding can be placed by a certain offset into the mold cavity so as to coun- teract the expansion of castings. 展开更多
关键词 Heavy steel casting Insulation padding Metal padding MODULUS Expansion SHIELDING
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SRResNet Performance Enhancement Using Patch Inputs and Partial Convolution-Based Padding
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作者 Safi Ullah Seong-Ho Song 《Computers, Materials & Continua》 SCIE EI 2023年第2期2999-3014,共16页
Due to highly underdetermined nature of Single Image Super-Resolution(SISR)problem,deep learning neural networks are required to be more deeper to solve the problem effectively.One of deep neural networks successful i... Due to highly underdetermined nature of Single Image Super-Resolution(SISR)problem,deep learning neural networks are required to be more deeper to solve the problem effectively.One of deep neural networks successful in the Super-Resolution(SR)problem is ResNet which can render the capability of deeper networks with the help of skip connections.However,zero padding(ZP)scheme in the network restricts benefits of skip connections in SRResNet and its performance as the ratio of the number of pure input data to that of zero padded data increases.In this paper.we consider the ResNet with Partial Convolution based Padding(PCP)instead of ZP to solve SR problem.Since training of deep neural networks using patch images is advantageous in many aspects such as the number of training image data and network complexities,patch image based SR performance is compared with single full image based one.The experimental results show that patch based SRResNet SR results are better than single full image based ones and the performance of deep SRResNet with PCP is better than the one with ZP. 展开更多
关键词 Single image super-resolution SRResNet patch inputs zero padding partial convolution based padding
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Effects of Fermentation Bed Padding on Intestinal Flora,Serum Biochemical Indexes and Immune Function of Growing-finishing Pigs 被引量:1
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作者 Guo Tongi Tian Jin +1 位作者 Li Lingyan Li Xiaochen 《Animal Husbandry and Feed Science》 CAS 2020年第3期1-5,共5页
[Objective]The paper was to study the effects of fermentation bed padding on intestinal flora,serum biochemical indexes and immune function of growing-finishing pigs.[Method]A total of 90 growing-finishing pigs(Duroc ... [Objective]The paper was to study the effects of fermentation bed padding on intestinal flora,serum biochemical indexes and immune function of growing-finishing pigs.[Method]A total of 90 growing-finishing pigs(Duroc × Landrace × Yorkshire)with the body weight of(30.5±0.8)kg were randomly divided into five groups,three replicates each group,six pigs each replicate.The padding of five groups were:50%rice husk+50%sawdust(control group),100%spent mushroom substrate of Pleurotus eryngii(100%spent mushroom substrate group),15%rice husk+15%sawdust+70%spent mushroom substrate(70%spent mushroom substrate group),25%rice husk+25%sawdust+50%spent mushroom substrate(50%spent mushroom substrate group),35%rice husk+35%sawdust+30%spent mushroom substrate(30%spent mushroom substrate group).The pre-trial lasted 7 d,and the formal trial lasted 90 d.[Result]Compared with the control group,the number of Escherichia col in 100%,70%and 50%spent mushroom substrate groups decreased by 35.4%,24.0%and 20.8%,respectively(P<0.05);the number of salmonella successively decreased by 29.4%,19.3%and 15.2%,respectively(P<0.05);the number of lactobacillus successively increased by 21.7%,15.9%and 12.2%,respectively(P<0.05);and the number of bifidobacteria successively increased by 20.2%,16.7%and 11.8%,respectively(P<0.05).Compared with the control group,the total serum protein content in 100%,70%,50%and 30%spent mushroom substrate groups increased by 30.6%,33.0%,28.0%and 18.4%,respectively(P<0.05);and the serum urea nitrogen content decreased by 32.4%,34.5%,33.9%and 22.0%,respectively(P<0.05).There was no significant difference in serum albumin,aspartate aminotransferase(AST)and alanine aminotransferase(ALT)between treatment groups and control group.The IgA,IgG,IgM and IL-6 levels in serum of each treatment group were significantly different from those of the control group(P<0.05).There was no significant difference in IgA,IgG,IgM and IL-6 levels among 100%,70%and 50%spent mushroom substrate groups.[Conclusion]It improves the balance of intestinal microecological flora of growing-finishing pigs and enhances the immune performance of pigs by using spent mushroom substrate of P.eryngii as the fermentation bed padding.15%rice husk+15%sawdust+70%spent mushroom substrate is the optimal proportion of spent mushroom substrate for growing-finishing pigs. 展开更多
关键词 Fermentation bed padding Growing-finishing pig Intestinal flora Serum biochemical indexes Immune function
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Padding Oracle攻击浅析
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作者 何伊圣 《信息安全与技术》 2011年第9期106-109,共4页
介绍了Padding Oracle攻击的基本原理及其危害,如何检查网站是否存在该类漏洞以及如何避免这类的攻击。
关键词 padding ORACLE ASP.NET OWASP DES RC2
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An Adaptive Padding Correlation Filter With Group Feature Fusion for Robust Visual Tracking
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作者 Zihang Feng Liping Yan +1 位作者 Yuanqing Xia Bo Xiao 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第10期1845-1860,共16页
In recent visual tracking research,correlation filter(CF)based trackers become popular because of their high speed and considerable accuracy.Previous methods mainly work on the extension of features and the solution o... In recent visual tracking research,correlation filter(CF)based trackers become popular because of their high speed and considerable accuracy.Previous methods mainly work on the extension of features and the solution of the boundary effect to learn a better correlation filter.However,the related studies are insufficient.By exploring the potential of trackers in these two aspects,a novel adaptive padding correlation filter(APCF)with feature group fusion is proposed for robust visual tracking in this paper based on the popular context-aware tracking framework.In the tracker,three feature groups are fused by use of the weighted sum of the normalized response maps,to alleviate the risk of drift caused by the extreme change of single feature.Moreover,to improve the adaptive ability of padding for the filter training of different object shapes,the best padding is selected from the preset pool according to tracking precision over the whole video,where tracking precision is predicted according to the prediction model trained by use of the sequence features of the first several frames.The sequence features include three traditional features and eight newly constructed features.Extensive experiments demonstrate that the proposed tracker is superior to most state-of-the-art correlation filter based trackers and has a stable improvement compared to the basic trackers. 展开更多
关键词 Adaptive padding context information correlation filter(CF) feature group fusion robust visual tracking
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Interest of the Padding in the Prevention of Lymphocele Production after Mastectomy with Axillary Dissection for Breast Cancer at Joliot Curie Cancer Center
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作者 Mohamed Ezzet Charfi Sidy Ka +3 位作者 Jaafar Thiam Adja Coumba Diallo Papa Souleymane Dieng Ahmadou Dem 《Journal of Cancer Therapy》 2020年第12期824-831,共8页
<strong>Introduction:</strong><span style="font-family:Verdana;"> The principal postoperative complication of mastectomies with</span><span style="font-family:Verdana;"&g... <strong>Introduction:</strong><span style="font-family:Verdana;"> The principal postoperative complication of mastectomies with</span><span style="font-family:Verdana;"> axillary dissection is the lymphocele that can last many months after surgery. The purpose of our study was to prevent its formation using the padding.</span><span style="font-family:""> </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> Sixty-one patients have been included in our study. The follow-up was 6 months. The patients were divided in two groups through a random draw (simple drainage and drainage associated with padding). All patients had a mastectomy with axillary dissection following the Madden technique. All quantities of lymphoceles during postoperative hospitalization and ambulatory care have been noted.</span><span style="font-family:""> </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> Twenty-five patients had benefited f</span><span style="font-family:Verdana;">rom</span><span style="font-family:Verdana;"> the padding and 36 of a simple axillary drainage. Six months after the surgery, the patients benefitting from the padding had a quantity of lymphocele equal to half that of the control group (761.83 mL against 1373.60 mL;p = 0.01). During the postoperative hospitalization, the quantities were of 362.80 mL for the padding group versus 630.83 mL;p < 0.01. The hospitalization period was shorter for the padding patients (3.72 days vs 5.14 days;p = 0.01). However, pain was greater for the padding group upon 6 months (0.26 vs 0.10;p = 0.04). On another note, padding does not influence the duration of the surgery.</span><span style="font-family:""> </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> The production of postoperative lymphocele is heterogenous, varying from one patient to another. Nevertheless, the padding of the mastectomy compartment and of the axillary cavity allow</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> a noticeable reduction of the produced quantity and of the hospitalization period at the expense of more pain.</span> 展开更多
关键词 MASTECTOMY Axillary Dissection LYMPHOCELE padding
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TD-LTE降Padding课题的技术研究
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作者 赵俊德 《中文科技期刊数据库(文摘版)工程技术》 2017年第8期00304-00308,共5页
随着网络的发展,移动终端上APP业务的丰富,尤其是微信,QQ等社交软件的应用普及会出现网络小数据量业务模型占比升高,小包业务多的现象,这样会造成MAC(Media Access Control)层的padding高的现象。通过使能下行Type1功能,可以有效降低MAC... 随着网络的发展,移动终端上APP业务的丰富,尤其是微信,QQ等社交软件的应用普及会出现网络小数据量业务模型占比升高,小包业务多的现象,这样会造成MAC(Media Access Control)层的padding高的现象。通过使能下行Type1功能,可以有效降低MAC层padding比例,提高RB的利用率。 展开更多
关键词 TD-LTE padding 调度 自适应
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Padding 权重化的卷积神经网络
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作者 刘之瑜 徐精诚 +2 位作者 罗长银 王豪石 张淑芬 《新一代信息技术》 2020年第21期7-13,共7页
图像经过卷积神经网络中的卷积操作会使图像的尺寸缩小,经过几次卷积后图像大小会不足以支持继续训练网络模型,采用边界填充(Padding)操作,在图像外围填充数值0,再进行卷积操作,经过一次卷积后输出的特征图矩阵与输入的图像矩阵有相同... 图像经过卷积神经网络中的卷积操作会使图像的尺寸缩小,经过几次卷积后图像大小会不足以支持继续训练网络模型,采用边界填充(Padding)操作,在图像外围填充数值0,再进行卷积操作,经过一次卷积后输出的特征图矩阵与输入的图像矩阵有相同的大小,解决训练深度受限的问题,使网络拥有更好的性能。但Padding操作在图像外围填充数值0,会使图像边缘信息模糊。本文提出参数化的Padding操作,将填充的数值0替换为带权重的数值,保持训练深度,保留图像的边缘信息。使用包含3个卷积层和2个全连接层的简单卷积神经网络,在Fashion-MNIST数据集上进行训练,准确率有1.52%的提升。 展开更多
关键词 卷积神经网络 Fashion-MNIST数据集 padding
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基于Padding权重化的卷积神经网络研究
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作者 刘之瑜 徐精诚 +2 位作者 罗长银 王豪石 张淑芬 《新一代信息技术》 2021年第3期14-20,共7页
图像经过卷积神经网络中的卷积操作会使图像的尺寸缩小,经过几次卷积后图像大小会不足以支持继续训练网络模型,采用边界填充(Padding)操作,在图像外围填充数值0,再进行卷积操作,经过一次卷积后输出的特征图矩阵与输入的图像矩阵有相同... 图像经过卷积神经网络中的卷积操作会使图像的尺寸缩小,经过几次卷积后图像大小会不足以支持继续训练网络模型,采用边界填充(Padding)操作,在图像外围填充数值0,再进行卷积操作,经过一次卷积后输出的特征图矩阵与输入的图像矩阵有相同的大小,解决训练深度受限的问题,使网络拥有更好的性能。但Padding操作在图像外围填充数值0,会使图像边缘信息模糊。本文提出参数化的Padding操作,将填充的数值0替换为带权重的数值,保持训练深度,保留图像的边缘信息。使用包含3个卷积层和2个全连接层的简单卷积神经网络,在Fashion-MNIST数据集上进行训练,准确率有1.52%的提升。 展开更多
关键词 卷积神经网络 Fashion-MNIST数据集 padding
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Break-Pad: efective padding machines for tor with break burst padding
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作者 Bin Huang Yanhui Du 《Cybersecurity》 2025年第4期197-214,共18页
Website Fingerprinting(WF)attacks enable a local eavesdropper to use metadata of packet fow,such as size,tim-ing,and direction,to infer the websites a user is visiting.This can damage the user privacy provided by anon... Website Fingerprinting(WF)attacks enable a local eavesdropper to use metadata of packet fow,such as size,tim-ing,and direction,to infer the websites a user is visiting.This can damage the user privacy provided by anonymity systems such as Tor.Tor has implemented the WF defense called Circuit Padding Framework,which provides an inter-face for developers to implement their own defenses.However,these defenses in the framework were overcome by the Deep Fingerprinting(DF)attack.In this paper,we propose a novel defense approach called break burst padding(Break-Pad),which injects a random number of padding packets into an incoming burst once the number of consecutive incoming packets exceeds a set number.We integrated Break-Pad into the existing Circuit Padding Framework.In addition,we have implemented two padding machines named August and October in the new framework and conducted experiments to evaluate these machines.In the open-world setting,our results show that August,with 29%bandwidth overhead,reduces Tik-Tok’s TPR by 14.48%and DF’s TPR by 22%.October outper-forms the best padding machine,RBB.With 36%bandwidth overhead,it drops Tik-Tok’s TPR to 74.24%and DF’s TPR to 65.36%.In the one-page setting,October further reduces the bandwidth overhead by 11%while achieving similar performance to RBB.In the information leak analysis,for the burst sequence feature of the trafc,October leaks at 2.453 bits,while the best comparable padding machine Interspace leaks at 2.629 bits. 展开更多
关键词 anonymity systems local eavesdropper website fingerprinting wf attacks break pad deep fingerprinting df attackin break burst padding circuit padding frameworkwhich circuit padding framework
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基于碳排放流的配电网广义碳势感知方法
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作者 田书欣 姜皓喆 +2 位作者 符杨 杨喜军 李振坤 《中国电机工程学报》 北大核心 2026年第5期1902-1913,I0014,共13页
配电系统碳势水平的实时评估和预测是实现配电侧能源流-碳流低碳优化运行的重要环节。针对配电系统的碳排放来源和控碳裕度的量化问题,该文提出一种基于碳排放流的配电网广义碳势感知方法。首先,在碳排放流理论基础上,利用配电网运行态... 配电系统碳势水平的实时评估和预测是实现配电侧能源流-碳流低碳优化运行的重要环节。针对配电系统的碳排放来源和控碳裕度的量化问题,该文提出一种基于碳排放流的配电网广义碳势感知方法。首先,在碳排放流理论基础上,利用配电网运行态势要素以及碳势要素计算得到考虑有功网损影响的配电网广义碳势,体现辐射状配电网节点碳势的空间差异性;其次,针对碳势数据的样本量有限和源荷信息的多变复杂特性,提出多元Padé逼近树突网络(multi-variate Padéapproximation dendrite net,multi Padé-DDNet)预测模型,通过强化碳势相关要素与模型输出的非线性映射关系,实现高精度广义碳势预测;然后,从关键点-分区-配电网递进结合的角度着手建立配电网节点碳势裕度指标、支路碳势裕度指标和网络碳排放裕度预警指标,并结合配电网不同区域、不同颗粒度的高碳势阈值,感知系统安全态势运行水平和动态高碳风险;最后,采用我国某地区实际配电网为算例,验证所提方法的可行性和有效性。 展开更多
关键词 广义碳势感知 配电网 碳排放流 多元Padé逼近树突网络 碳势预警指标
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基于自适应Padé逼近算法的Cole-Cole频散介质探地雷达时域有限元模拟与传播特征分析
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作者 王洪华 侯志阳 +2 位作者 王敏玲 吴祺铭 周飞 《地球物理学报》 北大核心 2026年第3期1304-1322,共19页
时域数值模拟是分析探地雷达(GPR)高频电磁波在Cole-Cole频散介质中传播特征的重要手段.由于Cole-Cole频散介质的复介电常数是关于角频率的分数次幂函数,代入频率域电磁波动方程并转化到时间域会出现时间分数阶导数,难以被常规时间整数... 时域数值模拟是分析探地雷达(GPR)高频电磁波在Cole-Cole频散介质中传播特征的重要手段.由于Cole-Cole频散介质的复介电常数是关于角频率的分数次幂函数,代入频率域电磁波动方程并转化到时间域会出现时间分数阶导数,难以被常规时间整数阶差分法离散.固定特征频率的Padé逼近算法虽可通过构造一组时间整数阶辅助微分方程来避免离散时间分数阶导数,但其对Cole-Cole频散介质的复相对介电常数估计误差较大,特别是当弛豫时间较短时误差急剧增加,降低模拟精度.为此,本文提出了一种自适应Padé逼近的Cole-Cole频散介质GPR时域有限元(FETD)模拟算法.该算法在利用固定特征频率的Padé逼近算法构建时域Cole-Cole频散介质电磁波动方程及其有限元方程基础上,首先将计算时窗平均划分为多个时间段,每个时间段内利用激励源子波频带范围的一系列频率作为特征频率进行模拟计算并与解析解对比.然后,选取相对误差最小的频率作为该时间段的特征频率,其时间迭代结果作为下一个时间段的迭代初值,依次迭代计算,直至最后一个时间段,从而在每个时间段迭代计算时自适应选择Padé逼近的特征频率.数值实验表明:与固定特征频率的Padé逼近相比,基于自适应Padé逼近的Cole-Cole频散介质GPR模拟精度更高.与非频散介质相比,高频电磁波在Cole-Cole频散介质中传播速度更慢,能量衰减更强.与Debye频散介质相比,高频电磁波在Cole-Cole频散介质中传播速度更快;能量衰减与Cole-Cole和Debye频散介质的衰减系数随频率变化曲线的交点有关,在交点左侧,能量衰减更强;在交点右侧,能量衰减更弱.弛豫因子越大,高频电磁波在Cole-Cole频散介质的传播速度越低;能量衰减受传播距离和弛豫因子的综合影响,传播距离越大、弛豫因子越小和传播距离越小、弛豫因子越大时,能量衰减越强. 展开更多
关键词 探地雷达 Cole-Cole频散介质 自适应Padé逼近 时域有限元法 传播特征分析
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基于OBE理念融合PAD教学模式在《医用高等数学》中的探索与实践
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作者 陈晨 朱乐玫 邴萍萍 《教育教学研究前沿》 2026年第2期87-89,共3页
《医用高等数学》中涵盖导数与微分、函数与极限、微分方程、定积分、不定积分等内容,教材是运用练习题、理论例题和案例修订帮助学生强化实践的方式,开展数字化教材建设的。若教师采用传统模式教学,可能造成医学与数学理论知识实际应... 《医用高等数学》中涵盖导数与微分、函数与极限、微分方程、定积分、不定积分等内容,教材是运用练习题、理论例题和案例修订帮助学生强化实践的方式,开展数字化教材建设的。若教师采用传统模式教学,可能造成医学与数学理论知识实际应用场景之间的脱节,增加学生的学习难度,所以教师应增加教学活动中的数字化载体,以OBE理念融合PAD教学模式开展教学,引导学生用数学去合理解决医学领域问题。基于此,本文结合实际思考,简要分析OBE理念融合PAD教学模式在《医用高等数学》中的价值,重点阐述OBE理念融合PAD教学模式在《医用高等数学》中的探索与实践。旨在为学生的全面发展提供支持。 展开更多
关键词 OBE理念 融合 PAD教学模式 《医用高等数学》 探索与实践
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“岗课赛证”融通视域下高职分析化学课程模块化教学设计与实践
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作者 刘佳 薛金召 《化学教育(中英文)》 北大核心 2026年第4期77-83,共7页
在职业教育改革深化背景下,本研究以高职分析化学为载体,探索“岗课赛证”融通的模块化教学。对接食品检验等岗位需求,重构课程为误差分析等6大模块,融入职业证书标准与竞赛项目。采用PAD课堂和校企双元模式,在3个班级(2实验组、1对照组... 在职业教育改革深化背景下,本研究以高职分析化学为载体,探索“岗课赛证”融通的模块化教学。对接食品检验等岗位需求,重构课程为误差分析等6大模块,融入职业证书标准与竞赛项目。采用PAD课堂和校企双元模式,在3个班级(2实验组、1对照组)开展实验。数据显示:实验组理论平均分85.6±3.2、实践88.4±2.8、职业素养优良率92.5%,均显著高于对照组(72.3±4.1、75.6±3.5、67.5%,p<0.01)。实验组化学检验员中级证书获取率98.7%,远高于对照组的70.0%。研究表明,该教学模式能提升学生专业能力与职业竞争力,为职教课程改革提供实践参考。 展开更多
关键词 岗课赛证 分析化学 模块化教学 高职教育 PAD课堂
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基于空间域与频域特征融合的虹膜呈现攻击检测
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作者 王财勇 孙娴蕴 +3 位作者 李林 赵光哲 何召锋 孙哲南 《中国图象图形学报》 北大核心 2026年第1期138-153,共16页
目的虹膜呈现攻击检测(presentation attack detection,PAD)是确保虹膜识别系统安全可靠的关键技术之一。针对现有检测方法在跨域场景下泛化性不足、难以有效检测合成虹膜的问题,提出一种基于空间域与频域特征融合的虹膜PAD模型。利用... 目的虹膜呈现攻击检测(presentation attack detection,PAD)是确保虹膜识别系统安全可靠的关键技术之一。针对现有检测方法在跨域场景下泛化性不足、难以有效检测合成虹膜的问题,提出一种基于空间域与频域特征融合的虹膜PAD模型。利用频域信息对环境变化的鲁棒性和合成/真实图像的频域差异,促使模型结合虹膜图像在空间域和频域中的互补特征,提升其检测精度和合成虹膜识别能力。方法首先对输入图像使用局部二值模式(local binary pattern,LBP)算法进行处理,生成空间域图像,接着使用离散余弦变换(discrete cosine transform,DCT)将空间域图像转换为频域图像;然后利用两个EfficientNet_b0作为骨干网络,分别对空间域和频域图像进行特征提取;进一步,通过两个空间通道融合注意力模块分别融合骨干网络所提取的中、高层特征;最后,在使用二元交叉熵损失函数的基础上,引入三元组损失进行联合训练,以提升模型所提特征的区分度。此外,为了让模型重点关注图像中的虹膜区域,引入了低频语义信息引导的注意力模块。结果在最新的虹膜PAD比赛LivDet-Iris 2023数据集上,将本文方法与比赛中的冠军方法及多种现有方法进行比较。相比于冠军方法,本文方法的综合检测错误率ACER1和ACER2分别下降9.32%和3.71%,其中合成虹膜的平均检测错误率APCER下降22.78%,打印虹膜的检测错误率APCER下降6.32%。相比于其他先进的现有方法,本文方法的综合检测错误率ACER1和ACER2分别下降8.91%和3.58%。此外,在LivDet-Iris 2023数据集上进行消融实验以验证所提模块的有效性,结果显示加入频域信息有效提升了模型分类真假虹膜的准确率。结论本文提出的虹膜呈现攻击检测模型有效利用图像的空间域和频域信息,提高了模型检测各类型虹膜呈现攻击的能力,且表现出更好的泛化性。本文模型和代码在https://github.com/xianyunsun/fre-iris-pad开放。 展开更多
关键词 呈现攻击检测(PAD) 虹膜识别 多域特征融合 注意力机制 合成虹膜
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