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Construction of Double Right-Border Binary Vector Carrying Non-Host Gene Rxo1 Resistant to Bacterial Leaf Streak of Rice 被引量:1
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作者 Xu Mei-rong XIA Zhi-hui +3 位作者 ZHAI Wen-xue Xu Jian-long ZHOU Yong-li LI Zhi-kang 《Rice science》 SCIE 2008年第3期243-246,共4页
Rxol cloned from maize is a non-host gene resistant to bacterial leaf streak of rice. pCAMBIA1305-1 with Rxo1 was digested with Sca I and NgoM IV and the double right-border binary vector pMNDRBBin6 was digested with ... Rxol cloned from maize is a non-host gene resistant to bacterial leaf streak of rice. pCAMBIA1305-1 with Rxo1 was digested with Sca I and NgoM IV and the double right-border binary vector pMNDRBBin6 was digested with Hpa I and Xma I. pMNDRBBin6 carrying the gene Rxo1 was acquired by ligation of blunt-end and cohesive end. The results of PCR, restriction enzyme analysis and sequencing indicated that the Rxo1 gene had been cloned into pMNDRBBin6. This double right-border binary vector, named as pMNDRBBin6-Rxol, will play a role in breeding marker-free plants resistant to bacterial leaf streak of rice by genetic transformation. 展开更多
关键词 Rxo1 gene double right-border binary vector RICE bacterial leaf streak selectable marker-free plant resistance gene
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Review: Plant Binary Vectors of Ti Plasmid in <i>Agrobacterium tumefaciens</i>with a Broad Host-Range Replicon of pRK2, pRi, pSa or pVS1
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作者 Norimoto Murai 《American Journal of Plant Sciences》 2013年第4期932-939,共8页
This review chronicles the development of the plant binary vectors of Ti plasmid in Agrobacterium tumefaciens during the last 30 years. A binary vector strategy was designed in 1983 to separate the T-DNA region in a s... This review chronicles the development of the plant binary vectors of Ti plasmid in Agrobacterium tumefaciens during the last 30 years. A binary vector strategy was designed in 1983 to separate the T-DNA region in a small plasmid from the virulence genes in avirulent T-DNA-less Ti plasmid. The small plant vectors with the T-DNA region have been simply now called binary Ti vectors. A binary Ti vector consist of a broad host-range replicon for propagation in A. tumeraciens, an antibiotic resistance gene for bacterial selection and the T-DNA region that would be transferred to the plant genome via the bacterial virulence machinery. The T-DNA region delimited by the right and left border sequences contains an antibiotic resistance gene for plant selection, reporter gene, and/or any genes of interest. The ColEI replicon was also added to the plasmid backbone to enhance the propagation in Escherichia coli. A general trend in the binary vector development has been to increase the plasmid stability during a long co-cultivation period of A. tumefaciens with the target host plant tissues. A second trend is to understand the molecular mechanism of broad host-range replication, and to use it to reduce the size of plasmid for ease in cloning and for higher plasmid yield in E. coli. The broad host-range replicon of VS1 was shown to be a choice of replicon over those of pRK2, pRi and pSA because of the superior stability and of small well-defined replicon. Newly developed plant binary vectors pLSU has the small size of plasmid backbone (4566 bp) consisting of VS1 replicon (2654 bp), ColE1 replicon (715 bp), a bacterial kanamycin (999 bp) or tetracycline resistance gene, and the T-DNA region (152 bp). 展开更多
关键词 Agrobacterium TUMEFACIENS binary vectors pRK2 PRI PSA pVS1 T-DNA Ti Plasmid
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Tetracycline-Based Binary Ti Vectors pLSU with Efficient Cloning by the Gateway Technology for <i>Agrobacterium tumefaciens</i>-Mediated Transformation of Higher Plants
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作者 Seokhyun Lee Guiying Su +1 位作者 Eric Lasserre Norimoto Murai 《American Journal of Plant Sciences》 2013年第7期1418-1426,共9页
We constructed small high-yielding binary Ti vectors with a bacterial tetracycline resistance gene to facilitate efficient cloning afforded by the Gateway Technology (Invitrogen) for Agrobacterium tumefaciens-mediated... We constructed small high-yielding binary Ti vectors with a bacterial tetracycline resistance gene to facilitate efficient cloning afforded by the Gateway Technology (Invitrogen) for Agrobacterium tumefaciens-mediated transformation of higher plants. The Gateway Technology vectors are kanamycin-based, thus tetracycline-based destination and expression vectors are easily selected for the antibiotic resistance in the Escherichia coli media. We reduced the size of the tetracycline resistance gene TetC from pBR322 to 1468 bp containing 1191 bp of the coding region, 93 bp of 5’-upstream, and 184 bp 3’-downstream region. The final size of binary Ti vector skeleton pLSU11 is 5034 bp. pLSU12 and 13 have the kanamycin resistance NPTII gene as a plant-selectable marker. pLSU13?and 15 contain the hygromycin resistance HPH gene as a selection marker. pLSU13 and 15 also have the β-glucuronidase (GUS) reporter gene in addition to the plant selection marker. We also constructed a mobilizable version of tetracycline-based binary Ti vector pLSU16 in which the mob function of ColE1 replicon was maintained for mobilization of the binary vector from E. coli to A. tumefaciens by tri-parental mating. The final size of binary Ti vector skeleton pLSU16 is 5580 bp. New tetracycline- based binary Ti vectors pLSU12 were found as effective as kanamycin-based vector pLSU2 in promoting a 10-fold increase in fresh weight yield of kanamycin-resistant calli after A. tumefaciens-mediated transformation of tobacco leaf discs. Using the Gateway Technology we introduced the plant-expressible GUSgene to the T-DNA of binary Ti vector pLSU12. Expression of the β-glucuronidase enzyme activity was demonstrated by histochemical staining of the GUS activity in transformed tobacco leaf discs. 展开更多
关键词 Agrobacterium TUMEFACIENS binary TI vectorS Gateway Technology pLSU Tobacco Leaf Disk Transformation TETRACYCLINE Resistance
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Incorporation of Resistance Gene into Tomato using Binary Vector System
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作者 赵淑慧 薛国雄 《Developmental and Reproductive Biology》 1995年第1期36-39,T001,共5页
Exoplants of tomato(Lycopersicon esculentum) leaf were transformed with Ti plasmids using binary vector system.After screening.with selection culture, kanamycin-resistant seedling were obtained from callus. Molecular ... Exoplants of tomato(Lycopersicon esculentum) leaf were transformed with Ti plasmids using binary vector system.After screening.with selection culture, kanamycin-resistant seedling were obtained from callus. Molecular hybridization proved the integration of Km gene into plant cell genome via A.tumefaciens. Higher activity of Nos-NPTase was demonstrated in the transformed plant,thus confirming the successful expression of the resistance gene in recipient cells. 展开更多
关键词 Tomato (Lycopersicon esculentum) binary vector Resistance gene TRANSFORMATION
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Credit Card Fraud Detection Using Weighted Support Vector Machine 被引量:3
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作者 Dongfang Zhang Basu Bhandari Dennis Black 《Applied Mathematics》 2020年第12期1275-1291,共17页
Credit card fraudulent data is highly imbalanced, and it has presented an overwhelmingly large portion of nonfraudulent transactions and a small portion of fraudulent transactions. The measures used to judge the verac... Credit card fraudulent data is highly imbalanced, and it has presented an overwhelmingly large portion of nonfraudulent transactions and a small portion of fraudulent transactions. The measures used to judge the veracity of the detection algorithms become critical to the deployment of a model that accurately scores fraudulent transactions taking into account case imbalance, and the cost of identifying a case as genuine when, in fact, the case is a fraudulent transaction. In this paper, a new criterion to judge classification algorithms, which considers the cost of misclassification, is proposed, and several undersampling techniques are compared by this new criterion. At the same time, a weighted support vector machine (SVM) algorithm considering the financial cost of misclassification is introduced, proving to be more practical for credit card fraud detection than traditional methodologies. This weighted SVM uses transaction balances as weights for fraudulent transactions, and a uniformed weight for nonfraudulent transactions. The results show this strategy greatly improve performance of credit card fraud detection. 展开更多
关键词 Support vector Machine binary Classification Imbalanced Data UNDERSAMPLING Credit Card Fraud
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Binary Image Steganalysis Based on Distortion Level Co-Occurrence Matrix 被引量:2
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作者 Junjia Chen Wei Lu +4 位作者 Yuileong Yeung Yingjie Xue Xianjin Liu Cong Lin Yue Zhang 《Computers, Materials & Continua》 SCIE EI 2018年第5期201-211,共11页
In recent years,binary image steganography has developed so rapidly that the research of binary image steganalysis becomes more important for information security.In most state-of-the-art binary image steganographic s... In recent years,binary image steganography has developed so rapidly that the research of binary image steganalysis becomes more important for information security.In most state-of-the-art binary image steganographic schemes,they always find out the flippable pixels to minimize the embedding distortions.For this reason,the stego images generated by the previous schemes maintain visual quality and it is hard for steganalyzer to capture the embedding trace in spacial domain.However,the distortion maps can be calculated for cover and stego images and the difference between them is significant.In this paper,a novel binary image steganalytic scheme is proposed,which is based on distortion level co-occurrence matrix.The proposed scheme first generates the corresponding distortion maps for cover and stego images.Then the co-occurrence matrix is constructed on the distortion level maps to represent the features of cover and stego images.Finally,support vector machine,based on the gaussian kernel,is used to classify the features.Compared with the prior steganalytic methods,experimental results demonstrate that the proposed scheme can effectively detect stego images. 展开更多
关键词 binary image steganalysis informational security embedding distortion distortion level map co-occurrence matrix support vector machine.
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Smart Fraud Detection in E-Transactions Using Synthetic Minority Oversampling and Binary Harris Hawks Optimization 被引量:1
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作者 Chandana Gouri Tekkali Karthika Natarajan 《Computers, Materials & Continua》 SCIE EI 2023年第5期3171-3187,共17页
Fraud Transactions are haunting the economy of many individuals with several factors across the globe.This research focuses on developing a mechanism by integrating various optimized machine-learning algorithms to ens... Fraud Transactions are haunting the economy of many individuals with several factors across the globe.This research focuses on developing a mechanism by integrating various optimized machine-learning algorithms to ensure the security and integrity of digital transactions.This research proposes a novel methodology through three stages.Firstly,Synthetic Minority Oversampling Technique(SMOTE)is applied to get balanced data.Secondly,SMOTE is fed to the nature-inspired Meta Heuristic(MH)algorithm,namely Binary Harris Hawks Optimization(BinHHO),Binary Aquila Optimization(BAO),and Binary Grey Wolf Optimization(BGWO),for feature selection.BinHHO has performed well when compared with the other two.Thirdly,features from BinHHO are fed to the supervised learning algorithms to classify the transactions such as fraud and non-fraud.The efficiency of BinHHO is analyzed with other popular MH algorithms.The BinHHO has achieved the highest accuracy of 99.95%and demonstrates amore significant positive effect on the performance of the proposed model. 展开更多
关键词 Metaheuristic algorithms K-nearest-neighbour binary aquila optimization binary grey wolf optimization BinHHO optimization support vector machine
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Defocus Blur Segmentation Using Local Binary Patterns with Adaptive Threshold 被引量:1
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作者 Usman Ali Muhammad Tariq Mahmood 《Computers, Materials & Continua》 SCIE EI 2022年第4期1597-1611,共15页
Enormousmethods have been proposed for the detection and segmentation of blur and non-blur regions of the images.Due to the limited available information about blur type,scenario and the level of blurriness,detection ... Enormousmethods have been proposed for the detection and segmentation of blur and non-blur regions of the images.Due to the limited available information about blur type,scenario and the level of blurriness,detection and segmentation is a challenging task.Hence,the performance of the blur measure operator is an essential factor and needs improvement to attain perfection.In this paper,we propose an effective blur measure based on local binary pattern(LBP)with adaptive threshold for blur detection.The sharpness metric developed based on LBP used a fixed threshold irrespective of the type and level of blur,that may not be suitable for images with variations in imaging conditions,blur amount and type.Contrarily,the proposed measure uses an adaptive threshold for each input image based on the image and blur properties to generate improved sharpness metric.The adaptive threshold is computed based on the model learned through support vector machine(SVM).The performance of the proposed method is evaluated using two different datasets and is compared with five state-of-the-art methods.Comparative analysis reveals that the proposed method performs significantly better qualitatively and quantitatively against all of the compared methods. 展开更多
关键词 Adaptive threshold blur measure defocus blur segmentation local binary pattern support vector machine
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An Improved Hybrid Space Vector PWM Technique for IM Drives
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作者 P. Muthukumar P. Melba Mary S. Jeevananthan 《Circuits and Systems》 2016年第9期2120-2131,共13页
In this paper, an improved hybrid space vector pulse width modulation (HSVPWM) technique is proposed for IM (induction motor) drives. The basic principle involved in the proposed random pulse width modulation (RPWM) c... In this paper, an improved hybrid space vector pulse width modulation (HSVPWM) technique is proposed for IM (induction motor) drives. The basic principle involved in the proposed random pulse width modulation (RPWM) cuddled SVPWM is amalgamating the pre-calculated switching timings for various sections of hexagonal space vector boundary and the random selection of carrier between two triangular signals, in order to disband acoustic switching noise spectrum with improved fundamental component. The arbitrary selection between triangular carriers, which is decided by digital signal states (Low or High) of the linear feedback shift register (LFSR) based pseudo random binary sequence (PRBS) generator. The SVPWM offers a control degree of freedom in terms of positioning of vectors inside every sampling interval and hence it has six possible variants of the voltage vectors arrangements in each sector. The developed HSVPWM is thoroughly analyzed in using the MATLAB? based simulation for all SVPWM variants. From the simulation and experimental results viz. harmonic spectrum, harmonic spread factor (HSF), total harmonic distortion (THD) etc., and the superiority of the proposed scheme such as better utilization of DC bus and the randomization of the harmonic power are evidenced. For the practical implementation, Xilinx XC3S500E FPGA device has been used. 展开更多
关键词 Harmonic Spread Factor Hybrid Space vector Pulse Width Modulation Pseudo Random binary Sequence Random Pulse Width Modulation
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基于自适应反馈机制的小差异化图像纹理特征信息数据检索
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作者 刘洋 毛克明 《江苏大学学报(自然科学版)》 CAS 北大核心 2025年第1期73-81,共9页
针对小差异化图像纹理相似度和噪声等因素导致纹理特征挖掘效果较差的问题,设计一种自适应反馈结合局部二值机制的小差异化图像纹理特征挖掘方法.使用规范割策略将图像数据各点拟作节点,使用节点间的连接线权重计算2点的相似度,采用支... 针对小差异化图像纹理相似度和噪声等因素导致纹理特征挖掘效果较差的问题,设计一种自适应反馈结合局部二值机制的小差异化图像纹理特征挖掘方法.使用规范割策略将图像数据各点拟作节点,使用节点间的连接线权重计算2点的相似度,采用支持向量机训练图像属性参数分类图像属性,进一步归纳图像类别.运用跳跃连接方法传输图像数据,将数据引入卷积神经网络剔除图像噪声.将中心点像素值当作反馈因子,创建自适应反馈判定条件,利用局部二值模式实现小差异化图像纹理特征挖掘.在MATLAB平台进行试验,从卷积神经网络收敛性、图像频谱纹理单元数、平均准确率、图像数据匹配度等方面进行了分析,分析结果表明:随着迭代次数不断增加,精度损失逐渐降低,基本收敛到稳定值,达到了预期训练效果;所提出方法挖掘的图像频谱纹理单元数3800个以上,更贴合人眼视觉信息;平均准确率为0.87,准确率@1、准确率@5和准确率@10的平均值分别为0.90、0.84和0.85;挖掘耗时低于5 s,图像数据匹配度高于90.3%,验证了所提出方法可在图像纹理特征识别操作中发挥应有作用. 展开更多
关键词 小差异化图像 纹理特征 数据挖掘 自适应反馈 属性分类 跳跃连接 局部二值模式 支持向量机
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改进MSE和BTSVM的往复压缩机轴承智能诊断研究
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作者 闫旭辉 武文革 邓诗俊 《机械设计与制造》 北大核心 2025年第12期277-282,共6页
针对往复压缩机轴承故障诊断识别准确率不高,故障特征信息耦合等问题,提出了基于改进MSE和优化BTSVM的故障诊断新方法。鉴于多尺度样本熵算法在冗余计算与特征提取效率方面存在的局限性,本研究深入剖析其多尺度处理策略与样本熵计算流程... 针对往复压缩机轴承故障诊断识别准确率不高,故障特征信息耦合等问题,提出了基于改进MSE和优化BTSVM的故障诊断新方法。鉴于多尺度样本熵算法在冗余计算与特征提取效率方面存在的局限性,本研究深入剖析其多尺度处理策略与样本熵计算流程,针对性地实施了优化措施。由此,本文提出了改进多尺度样本熵算法(IMSE),旨在显著提升算法的计算效率与特征提取精度。其次,针对传统纠错码无法确定码长及最优排列顺序这两方面的不足,将Hadamard矩阵应用于纠错码,提出一种基于Hadamard纠错码结合二叉树支持向量机(BTSVM)的故障识别方法。最后,将两种改进方法进行混合应用于往复压缩机故障诊断中,结果表明,本方法不但提高了故障诊断的准确率,还极大地加快了故障诊断的计算速度。 展开更多
关键词 往复压缩机 改进多尺度样本熵算法 纠错码 二叉树支持向量机 故障诊断
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乡村景观改造高度集聚特征提取算法
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作者 杨志勇 郭宗平 《计算机仿真》 2025年第3期145-149,共5页
在乡村景观改造中,空间数据往往会受到噪声的影响,导致高度集聚特征的提取受到干扰或误差,使得对景观改造高度集聚特征提取精度降低。为了准确提取景观改造高度集聚特征,提出一种乡村景观改造高度集聚特征提取算法。使用遥感数据采集景... 在乡村景观改造中,空间数据往往会受到噪声的影响,导致高度集聚特征的提取受到干扰或误差,使得对景观改造高度集聚特征提取精度降低。为了准确提取景观改造高度集聚特征,提出一种乡村景观改造高度集聚特征提取算法。使用遥感数据采集景观改造图像,通过非下采样Contourlet变换(Nonsubsampled contourlet transform,NSCT)提取图像不同方向的NSCT域系数,并通过改进BayesShrink阈值处理方法以去除噪声。应用模糊理论构建模糊阈值函数,处理NSCT域系数,得到去噪后的景观改造图像。引入局部二值模式算法(Local Binary Patterns,LBP)生成景观改造低密度特征图,利用旋转不变原则对特征图展开转换。通过滑动窗口遍历每个对象,统计各个对象在不同模式下的量级,得到LBP特征。将不同特征组成多维特征向量,并输入到支持向量机以提取景观改造的高度集聚特征。实验结果表明,所提方法可以得到高精度和高效率的乡村景观改造高度集聚特征提取结果。 展开更多
关键词 乡村景观改造 高度集聚特征 多维特征向量 局部二值模式算法
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基于深度学习的电力电缆故障诊断与定位策略研究
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作者 张羽翔 胡雨时 +1 位作者 张宏志 鞠杨 《微型电脑应用》 2025年第6期20-25,共6页
电力电缆内部绝缘失效或外部损坏时,会导致所在的配电区域发生不对称故障,进而引发局部停电。为了快速且准确地对电缆故障进行诊断和分类,采用一维卷积神经网络(1D-CNN)分类器和二进制支持向量机(BSVM)分类器,提出一种基于深度学习的电... 电力电缆内部绝缘失效或外部损坏时,会导致所在的配电区域发生不对称故障,进而引发局部停电。为了快速且准确地对电缆故障进行诊断和分类,采用一维卷积神经网络(1D-CNN)分类器和二进制支持向量机(BSVM)分类器,提出一种基于深度学习的电力电缆故障诊断与定位策略。采用ATP-EMTP程序模拟并采集地下电缆发送的端信号,利用分数离散余弦变换(FrDCT)和奇异值分解(SVD)实现数据特征提取和化简,采用BSVM分类器进行电缆故障检测,采用1D-CNN分类器进行电缆故障的分类和定位。仿真结果表明,当分数因子α=0.8时,故障定位准确率为99.6%,最低执行时间为0.15 s,最大错误率为0.0789%,所提策略可以有效实现电缆的故障诊断与定位。 展开更多
关键词 电力电缆 深度学习 故障诊断与定位 一维卷积神经网络 二进制支持向量机
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基于BPSO-PSO-LSSVM算法的上肢sEMG分类
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作者 贠今天 苗冠 +1 位作者 李帅 耿梓敬 《科学技术与工程》 北大核心 2025年第18期7686-7692,共7页
作为与人体运动密切相关的生理信号,表面肌电(surface electromyography, sEMG)信号的解析在人机交互领域具有重要的作用。针对肌电信号分类效率和精度难以兼顾的问题,提出了一种特征筛选与分类器超参数优化相结合的上肢sEMG分类方法,... 作为与人体运动密切相关的生理信号,表面肌电(surface electromyography, sEMG)信号的解析在人机交互领域具有重要的作用。针对肌电信号分类效率和精度难以兼顾的问题,提出了一种特征筛选与分类器超参数优化相结合的上肢sEMG分类方法,该方法采用二进制粒子群优化(binary particle swarm optimization, BPSO)算法对特征进行筛选后,进一步采用粒子群优化(particle swarm optimization, PSO)算法调整最小二乘支持向量机(least squares support vector machine, LSSVM)的超参数。通过采集人上体4个部位的表面肌电信号并提取其中48维特征,对上肢常见的4种动作进行分类实验,结果表明,BPSO-PSO-LSSVM算法仅保留肌电数据的21维特征,得到的平均分类准确率达到97.54%,证明该方法可以有效筛选出用于上肢动作分类的最佳特征组合,并且提高运动分类的准确率。 展开更多
关键词 表面肌电信号 特征选择 二进制粒子群优化 粒子群优化 动作分类 最小二乘支持向量机
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基于改进的LBP和Gabor滤波器的纹理特征提取方法 被引量:1
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作者 陈佳明 陈旭 +1 位作者 任硕 邸宏伟 《南京信息工程大学学报》 北大核心 2025年第2期227-234,共8页
纹理提取是计算机视觉领域的一项重要任务,纹理提取的质量对纹理分类的准确性具有关键影响.传统单一的纹理提取方法难以准确描述各类纹理的特征.本文提出一种基于改进的位置局部二值模式(IPLBP)和Gabor滤波器的纹理提取算法,其中,改进... 纹理提取是计算机视觉领域的一项重要任务,纹理提取的质量对纹理分类的准确性具有关键影响.传统单一的纹理提取方法难以准确描述各类纹理的特征.本文提出一种基于改进的位置局部二值模式(IPLBP)和Gabor滤波器的纹理提取算法,其中,改进算法在局部二值模式(LBP)的基础上通过提取纹理位置信息来提高纹理描述能力.利用改进后的LBP算法提取局部纹理信息,Gabor滤波器提取全局纹理信息,将两种特征信息进行融合后使用支持向量机(SVM)进行分类.实验结果表明,所提出的算法在纹理材质分类任务上展现出了良好的性能.相比传统的LBP算法,该算法能够更准确地捕捉不同纹理特征之间的差异. 展开更多
关键词 纹理提取 局部二值模式 GABOR滤波器 支持向量机
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SIMD-to-RVV动态二进制翻译中的跨架构编程模型适配优化
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作者 赖远明 李亚龙 +3 位作者 胡瀚之 谢梦瑶 王喆 武成岗 《计算机研究与发展》 北大核心 2025年第6期1469-1491,共23页
RISC-V因其开源和模块化设计等特性,已在嵌入式领域取得显著成功,并逐步向高性能计算(HPC)领域拓展.面向HPC的RISC-V硬件(如Sophon SG2042多核处理器)已展现出与x86/ARM同类型产品相当的性能水平,但不完善的软件生态是阻碍其发展的最大... RISC-V因其开源和模块化设计等特性,已在嵌入式领域取得显著成功,并逐步向高性能计算(HPC)领域拓展.面向HPC的RISC-V硬件(如Sophon SG2042多核处理器)已展现出与x86/ARM同类型产品相当的性能水平,但不完善的软件生态是阻碍其发展的最大障碍之一.开发了面向RISC-V的进程级动态二进制翻译(DBT)器RVBT,用于将成熟的x86软件生态移植到RISC-V平台,加速RISC-V在HPC领域的应用进程.针对HPC程序广泛依赖SIMD指令的特性,聚焦于解决SIMD与RVV间显著的编程模型差异导致的翻译性能瓶颈问题,提出了3项创新的优化方案.x86SIMD将数据类型硬编码于操作码,而RVV需动态配置vtype和掩码寄存器,这导致直接翻译产生了大量冗余操作,严重拉低了翻译运行的效率.通过充分利用程序数据类型的局部性,优化方案可删除跨架构适配编程模型导致的冗余设置,混合使用浮点扩展和向量扩展翻译SIMD指令并按需同步数据,大幅提升了SIMD指令的翻译运行效率.3项优化方案具备通用性,也适用于ARM平台的SIMD到RVV的翻译.实验表明,以SPECCPU2006作为测试集,优化方案对csrr,vsetvl,vsetvli指令的平均动态消除率分别达到了100%,100%和56.31%,在浮点测试集上,掩码设置操作的平均动态消除率达到了74.66%,数据的平均动态同步率为67.35%.优化后的RVBT在整点和浮点测试集上的平均运行效率达到了本地执行的47.39%和40.06%,相比优化前的加速比分别为1.21和8.31,并远超QEMU18.84%和4.81%,展现出了应用于部分HPC场景的潜力. 展开更多
关键词 二进制翻译 RISC-V向量扩展 x86SIMD 跨架构编程模型适配 浮点计算 冗余设置消除 混合翻译
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基于机器学习的富硒土壤预测模型的构建与比较——以江西省信丰县油山地区为例
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作者 杨兰 王运 +4 位作者 邹勇军 胡宝群 李满根 张安 朱满怀 《吉林大学学报(地球科学版)》 北大核心 2025年第5期1629-1643,共15页
利用未知硒数据快速、高效、精准地圈定富硒土壤,需构建预测富硒土壤的最佳模型。从1 277个1∶5万表层土壤的地球化学数据中选取502个数据组成数据集,以w(Zn)、w(K_(2)O)、w(P)、w(Mo)、w(Mn)、w(Cr)、pH、D(泥盆系)为自变量,以是否富S... 利用未知硒数据快速、高效、精准地圈定富硒土壤,需构建预测富硒土壤的最佳模型。从1 277个1∶5万表层土壤的地球化学数据中选取502个数据组成数据集,以w(Zn)、w(K_(2)O)、w(P)、w(Mo)、w(Mn)、w(Cr)、pH、D(泥盆系)为自变量,以是否富Se为因变量,运用SPSS Modeler 18软件构建二元Logistic回归模型、多层感知器神经网络模型、随机森林模型及支持向量机模型(包括线性、多项式、径向基和Sigmoid核函数),并通过35组土壤样品实测数据进行验证。结果表明:二元Logistic回归模型、多层感知器神经网络模型、随机森林模型及(线性、多项式、径向基、Sigmoid)支持向量机模型的预测准确率和验证总体准确率分别为88.8%和94.3%、91.0%和97.1%、96.6%和97.1%、87.9%和97.1%、86.1%和94.3%、86.9%和94.3%、80.3%和91.4%;以上模型的曲线下面积(AUC)值分别为0.948、0.950、0.993、0.937、0.945、0.928和0.873,随机森林模型的准确率和稳定性最佳。同时,本次研究发现了清洁富硒土壤及绿色富硒山稻,表明该方法在富硒土壤预测中具有可行性,且可进一步拓展到地质找矿及环境监测等领域。 展开更多
关键词 富硒土壤 机器学习 二元Logistic回归模型 多层感知器神经网络模型 随机森林模型 支持向量机模型
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基于约束图的鲁棒半监督不相关岭回归聚类
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作者 朱建勇 王敬文 +1 位作者 杨辉 聂飞平 《控制与决策》 北大核心 2025年第4期1321-1330,共10页
岭回归由于简单高效被用于处理各种机器学习任务,并取得令人称赞的结果.然而,当岭回归直接应用于聚类时,易触发平凡解.为解决此问题,提出基于约束图的鲁棒不相关岭回归方法(RURCG).首先,利用广义不相关约束使得岭回归嵌入流形结构,保证... 岭回归由于简单高效被用于处理各种机器学习任务,并取得令人称赞的结果.然而,当岭回归直接应用于聚类时,易触发平凡解.为解决此问题,提出基于约束图的鲁棒不相关岭回归方法(RURCG).首先,利用广义不相关约束使得岭回归嵌入流形结构,保证其聚类时存在闭式解;然后,为了避免异常数据对聚类的影响,对岭回归的误差项施加二值向量,该向量的元素具有明确的物理意义,若数据正常,则其值为1,否则为0;接着,对岭回归嵌入拉普拉斯构造来获取数据的局部几何结构,使得聚类结构更为充分,其中涉及的图矩阵包含成对约束和标签信息;最后,运用迭代优化策略求解目标函数,通过在8个基准数据集上的仿真实验验证所提出方法的有效性. 展开更多
关键词 半监督聚类 岭回归 不相关约束 二值向量 辅助信息 图正则化
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An efficient Agrobacterium-mediated transient expression system in tomato leaflets
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作者 Ge Wang Jiucheng Zhang +6 位作者 Xuemei Zhang Di Ma Minyu Tian Chunyan Chen Jiapin He Zhilong Bao Fangfang Ma 《Horticultural Plant Journal》 2025年第4期1703-1706,共4页
The Agrobacterium-mediated transient expression system with conventional binary vectors is well established in tobacco leaves,while the same system applied to tomato leaflets has relatively low expression efficiency.H... The Agrobacterium-mediated transient expression system with conventional binary vectors is well established in tobacco leaves,while the same system applied to tomato leaflets has relatively low expression efficiency.However,impacts of the leaf age,inoculation method and incubation condition after Agrobacterium infiltration on transient protein expression efficiency are seldom investigated.In this study,we optimize Agrobacterium-mediated transient expression system using conventional binary vectors to achieve the high efficiency of target gene expression in tomato leaflets.We transiently express GFP and a nucleus-localized gene SlUVI4 fused with GFP in detached 10-,20-,and 30-day-old leaflets.The cutting points of leaflets are embedded in MS medium after the Agrobacterium-mediated vacuum infiltration,and all leaflets are kept in the dark before use.The 10-and 30-day-old leaflets have more damage than 20-day-old leaflets after the infiltration. 展开更多
关键词 agrobacterium infiltration leaf age tobacco leaveswhile incubation condition conventional binary vectors agrobacterium mediated transient expression inoculation method tomato leaflets
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基于局部自适应明暗模式的图像纹理特征提取方法
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作者 李江美 陈熙 《激光杂志》 北大核心 2025年第7期101-110,共10页
局部二值模式(LBP)只考虑中心像素与不同方向上相邻像素间的明暗趋势,并不能精确提取不同方向上的明暗强度信息。此外,不同的图像结构处于相同的明暗区域时,也可能被编码为同一种模式。因此,为解决以上问题,提出一种基于局部明暗强度的... 局部二值模式(LBP)只考虑中心像素与不同方向上相邻像素间的明暗趋势,并不能精确提取不同方向上的明暗强度信息。此外,不同的图像结构处于相同的明暗区域时,也可能被编码为同一种模式。因此,为解决以上问题,提出一种基于局部明暗强度的图像局部纹理算法,即局部自适应明暗强度矢量二值模式,该算法由局部自适应明暗矢量模式和局部明暗强度模式两个特征分量组成。局部自适应明暗矢量模式在MxN窗口内计算不同方向上的正负平均矢量阈值,以此精确地提取每个中心像素周围不同方向上不同明暗强度特征;而局部明暗强度模式根据中心像素与相邻像素之间明暗程度进行排序编码,对于提取相同明暗区域的不同纹理特征更加有效。另外,为提高低分辨纹理图像的识别性能,建立多尺度纹理高斯金字塔进行特征融合。最后,使用随机森林和最近邻分类器在5个图像数据集上进行分类实验,实验验证了该算法的有效性。 展开更多
关键词 图像局部特征 局部自适应明暗强度矢量二值模式 多尺度高斯金字塔 图像特征融合 随机森林
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