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基于改进YOLOv5s的储粮害虫检测方法研究
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作者 陈卫东 王莹 +1 位作者 丁俊丹 何为 《河南工业大学学报(自然科学版)》 CAS 北大核心 2024年第5期111-120,共10页
针对当前因检测背景复杂、粮虫个体较小等因素造成的储粮害虫检测准确率较低、漏检、误检的现状,提出一种改进YOLOv5s的检测方法。使用MobileNetv3作为YOLOv5s模型的主干特征提取网络,并将其SE注意力机制修改为ECA模块,减少计算量和参数... 针对当前因检测背景复杂、粮虫个体较小等因素造成的储粮害虫检测准确率较低、漏检、误检的现状,提出一种改进YOLOv5s的检测方法。使用MobileNetv3作为YOLOv5s模型的主干特征提取网络,并将其SE注意力机制修改为ECA模块,减少计算量和参数量;同时,调整PANet网络为加权双向特征金字塔BiFPN结构,增强特征融合能力;颈部网络部分引入Swin Transformer,解决全局提取特征不足的问题,提升识别精度;采用EIOU损失函数,提高模型的收敛速度。结果表明:改进后的模型mAP达到97.8%,FPS达到133.3,与主流目标检测模型比较,表现出较强的鲁棒性和泛化能力;改进的YOLOv5s检测模型能克服复杂环境的影响,显著提高储粮害虫在密集分布及遮挡条件下的检测效果。研究结果为移动设备上实现储粮害虫实时检测提供技术参考。 展开更多
关键词 储粮害虫 YOLOv5s MobileNetv3 BiFPN Swin transformer EIOU
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Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2)体系相平衡研究
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作者 陈昌 任国兴 +2 位作者 韩文生 冉孟杰 陈雯 《有色金属(冶炼部分)》 CAS 北大核心 2023年第10期55-63,共9页
为揭示Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2)多元含铌炉渣体系中的铌矿物的定向结晶规律,采用高温相平衡—冷淬—SEM-EDS/XRD/EMPA试验方法,考察了温度、钙硅比(CaO/SiO_(2))、Nb_(2)O_(5)含量等因素对炉渣相平衡关系的影响... 为揭示Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2)多元含铌炉渣体系中的铌矿物的定向结晶规律,采用高温相平衡—冷淬—SEM-EDS/XRD/EMPA试验方法,考察了温度、钙硅比(CaO/SiO_(2))、Nb_(2)O_(5)含量等因素对炉渣相平衡关系的影响,并构建了含铌矿物结晶析出的优势相图。结果表明:铌的结晶矿物主要有三种,分别为Ca_(2)Nb_(2)O_(7)、Ca_((14-x))Nb_((2+x))Si_(8)O_((35+1.5x))和3CaO·MgO·Nb_(2)O_(5);铌先富集于液相,相较于脉石组分,含铌固相为后析出相;CaO/SiO_(2)增加会使含铌固相优势区间发生从Ca_(2)Nb_(2)O_(7)相到Ca_((14-x))Nb_((2+x))Si_(8)O_((35+1.5x))相、再到3CaO·MgO·Nb_(2)O_(5)相的转变。Ca_(2)Nb_(2)O_(7)相的优势析晶区间为:温度1050~1200℃,C/S=0.8~1.2。Nb_(2)O_(5)在Ca_((14-x))Nb_((2+x))Si_(8)O_((35+1.5x))相中的嵌布质量浓度在18.5%~19.5%。 展开更多
关键词 铌资源 相平衡 矿相转化 Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2)
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MULTI-SPECTRAL AND HYPERSPECTRAL IMAGE FUSION USING 3-D WAVELET TRANSFORM 被引量:5
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作者 Zhang Yifan He Mingyi 《Journal of Electronics(China)》 2007年第2期218-224,共7页
Image fusion is performed between one band of multi-spectral image and two bands of hyperspectral image to produce fused image with the same spatial resolution as source multi-spectral image and the same spectral reso... Image fusion is performed between one band of multi-spectral image and two bands of hyperspectral image to produce fused image with the same spatial resolution as source multi-spectral image and the same spectral resolution as source hyperspeetral image. According to the characteristics and 3-Dimensional (3-D) feature analysis of multi-spectral and hyperspectral image data volume, the new fusion approach using 3-D wavelet based method is proposed. This approach is composed of four major procedures: Spatial and spectral resampling, 3-D wavelet transform, wavelet coefficient integration and 3-D inverse wavelet transform. Especially, a novel method, Ratio Image Based Spectral Resampling (RIBSR)method, is proposed to accomplish data resampling in spectral domain by utilizing the property of ratio image. And a new fusion rule, Average and Substitution (A&S) rule, is employed as the fusion rule to accomplish wavelet coefficient integration. Experimental results illustrate that the fusion approach using 3-D wavelet transform can utilize both spatial and spectral characteristics of source images more adequately and produce fused image with higher quality and fewer artifacts than fusion approach using 2-D wavelet transform. It is also revealed that RIBSR method is capable of interpolating the missing data more effectively and correctly, and A&S rule can integrate coefficients of source images in 3-D wavelet domain to preserve both spatial and spectral features of source images more properly. 展开更多
关键词 Image fusion 3-Dimensional 3-D) wavelet transform MULTI-SPECTRAL HYPERSPECTRAL
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Multiple description scalable video coding based on 3D lifted wavelet transform 被引量:3
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作者 KIM Yong-deak 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第5期857-863,共7页
In this work, a new method to deal with the unconnected pixels in motion compensated temporal filtering (MCTF) is presented, which is designed to improve the performance of 3D lifted wavelet coding. Furthermore, multi... In this work, a new method to deal with the unconnected pixels in motion compensated temporal filtering (MCTF) is presented, which is designed to improve the performance of 3D lifted wavelet coding. Furthermore, multiple description scalable coding (MDSC) is investigated, and novel MDSC schemes based on 3D wavelet coding are proposed, using the lifting imple- mentation of temporal filtering. The proposed MDSC schemes can avoid the mismatch problem in multiple description video coding, and have high scalability and robustness of video transmission. Experimental results showed that the proposed schemes are feasible and adequately effective. 展开更多
关键词 Multiple description SCALABLE coding (MDSC) MOTION compensated temporal filtering (MCTF) Block-split bidi-rectional MOTION estimation 3D lifted wavelet transform
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AN EFFICIENT 3-DIMENSIONAL DISCRETE WAVELET TRANSFORM ARCHITECTURE FOR VIDEO PROCESSING APPLICATION 被引量:1
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作者 Ganapathi Hegde Pukhraj Vaya 《Journal of Electronics(China)》 2012年第6期534-540,共7页
This paper presents an optimized 3-D Discrete Wavelet Transform (3-DDWT) architecture. 1-DDWT employed for the design of 3-DDWT architecture uses reduced lifting scheme approach. Further the architecture is optimized ... This paper presents an optimized 3-D Discrete Wavelet Transform (3-DDWT) architecture. 1-DDWT employed for the design of 3-DDWT architecture uses reduced lifting scheme approach. Further the architecture is optimized by applying block enabling technique, scaling, and rounding of the filter coefficients. The proposed architecture uses biorthogonal (9/7) wavelet filter. The architecture is modeled using Verilog HDL, simulated using ModelSim, synthesized using Xilinx ISE and finally implemented on Virtex-5 FPGA. The proposed 3-DDWT architecture has slice register utilization of 5%, operating frequency of 396 MHz and a power consumption of 0.45 W. 展开更多
关键词 3-D Discrete wavelet transform (3-DDWT) Lifting scheme PIPELINING Video coding Low power
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Effect of hot deformation on α→β phase transformation in 47Zr-45Ti-5Al-3V alloy 被引量:1
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作者 Yuan-biao TAN Li-yuan Ji +3 位作者 Wen-chang LIU Song XIANG Fei ZHAO Yi-long LIANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第10期1947-1957,共11页
The effect of strain rate and deformation temperature on theα→βphase transformation in 47Zr-45Ti-5Al-3V alloy with an initial widmanstattenαstructure was investigated.At the deformation temperature of 550°C,t... The effect of strain rate and deformation temperature on theα→βphase transformation in 47Zr-45Ti-5Al-3V alloy with an initial widmanstattenαstructure was investigated.At the deformation temperature of 550°C,the volume fraction ofαphase decreased with increasing strain rate.At 600 and 650°C,the volume fraction ofαphase firstly increased to a maximum value with increasing strain rate from 1×10-3 to 1×10-2 s-1,and then decreased.At 700°C,the microstructure consisted of singleβphase.At a given strain rate,the volume fraction ofαphase decreased with increasing deformation temperature.With decreasing strain rate and increasing deformation temperature,the volume fraction and size of globularαphase increased.At 650°C and 1×10-3 s-1,the lamellarαphase was fully globularized.The variation in the volume fraction and morphology ofαphase with strain rate and deformation temperature significantly affected the hardness of 47Zr-45Ti-5Al-3V alloy. 展开更多
关键词 47Zr-45Ti-5Al-3V alloy hot deformation phase transformation Vickers hardness microstructure
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AN ALGORITHM FOR CODING VIDEO SIGNAL BASED ON 3-D WAVELET TRANSFORMATION
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作者 Wu Peng Zhang Miaolan Li Xianglin (Dept. of Electrical Eng., Graduate School, Uni. of Sci. and Tech. of China, Beijing 100039) 《Journal of Electronics(China)》 2000年第2期97-107,共11页
This paper presents an algorithm for coding video signal based on 3-D wavelet transformation. When the frame order t of a video signal is replaced by order 2, the video signal can be looked as a block in 3-D space. Af... This paper presents an algorithm for coding video signal based on 3-D wavelet transformation. When the frame order t of a video signal is replaced by order 2, the video signal can be looked as a block in 3-D space. After splitting the block into smaller sub-blocks, imitate the method of 2-D wavelet transformation for images, we can transform the sub-blocks with 3-D wavelet. Most of video signal energy is in the decomposed low-frequency sub-bands. These sub-bands affect the visual quality of the video signal most. Quantizing different sub-bands with different precision and then entropy encoding each sub-band, we can eliminate inter- and intra-frame redundancy of the video signal and compress data. Our simulation experiments show that this algorithm can achieve very good result. 展开更多
关键词 waveletS 3-D wavelet transformATION VIDEO signal CODING
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Synchronization of two 3-scroll hyperchaotic attractors using wavelet transform
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作者 Li Jian Zhou Jiliu Wang Yong Zhi Yong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第2期387-389,共3页
The synchronization of two 3-scroll hyperchaotie attractors is realized based on wavelet transform and single variables' feedstock. In the transmitter, one signal is decomposed by wavelet transform and the detailed i... The synchronization of two 3-scroll hyperchaotie attractors is realized based on wavelet transform and single variables' feedstock. In the transmitter, one signal is decomposed by wavelet transform and the detailed information is removed, then the component with low frequency is reconstructed and sent into the channel In the receiver, the received signal is used as the feedback signal to realize the synchronization of two chaotic systems. Using this synchronous method, the transmitting signal is transported in compressible way, the system resource is saved, furthermore, because the transported signal is not a whole chaotic signal, the performance of security of the system is improved. 展开更多
关键词 wavelet transform 3-scroll hyperehaotie attractor SYNCHRONIZATION single variable's feedback.
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3-D Wavelet Transform for Very Low Bit-Rate Video Coding
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作者 Hou Weidong Mo Yulong Zhu Qiuyu Wei Chunlong (Shool of Communication and Information Engineering, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第2期48-51,共4页
A new improved Goh's 3 D wavelet transform(WT) coding scheme is presented in this paper. The new scheme has great advantages including a simple code structure, low computation cost and good performance in PSNR, c... A new improved Goh's 3 D wavelet transform(WT) coding scheme is presented in this paper. The new scheme has great advantages including a simple code structure, low computation cost and good performance in PSNR, compression ratios and visual quality of reconstructions, when compared to the other existing 3 D WT coding methods and the 2 D WT based coding methods. The new 3 D WT coding scheme is suitable for very low bit rate video coding. 展开更多
关键词 video coding video compression very low bit rate 3 D wavelet transform
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Very Low Bit Rate Video Coding Using Motion Compensated 3 D Wavelet Transform
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作者 HOU Wei dong MO Yu long (School of Communication and Information Engineering, Shanghai University) HU Hai ping (School of Sciences, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第4期342-344,共3页
A new motion compensated 3 D wavelet transform (MC 3DWT) video coding scheme is presented in this paper. The new coding scheme has a good performance in average PSNR, compression ratio and visual quality of reconst... A new motion compensated 3 D wavelet transform (MC 3DWT) video coding scheme is presented in this paper. The new coding scheme has a good performance in average PSNR, compression ratio and visual quality of reconstructions compared with the existing 3 D wavelet transform (3DWT) coding methods and motion compensated 2 D wavelet transform (MC WT) coding method. The new MC 3DWT coding scheme is suitable for very low bit rate video coding. 展开更多
关键词 video coding very low bit rate 3 D wavelet transform motion compensation
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Defects Recognition of 3D Braided Composite Based on Dual-Tree Complex Wavelet Packet Transform
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作者 贺晓丽 王瑞 《Journal of Donghua University(English Edition)》 EI CAS 2015年第5期749-752,共4页
Textile-reinforced composites,due to their excellent highstrength-to-low-mass ratio, provide promising alternatives to conventional structural materials in many high-tech sectors. 3D braided composites are a kind of a... Textile-reinforced composites,due to their excellent highstrength-to-low-mass ratio, provide promising alternatives to conventional structural materials in many high-tech sectors. 3D braided composites are a kind of advanced composites reinforced with 3D braided fabrics; the complex nature of 3D braided composites makes the evaluation of the quality of the product very difficult. In this investigation,a defect recognition platform for 3D braided composites evaluation was constructed based on dual-tree complex wavelet packet transform( DT-CWPT) and backpropagation( BP) neural networks. The defects in 3D braided composite materials were probed and detected by an ultrasonic sensing system. DT-CWPT method was used to analyze the ultrasonic scanning pulse signals,and the feature vectors of these signals were extracted into the BP neural networks as samples. The type of defects was identified and recognized with the characteristic ultrasonic wave spectra. The position of defects for the test samples can be determined at the same time. This method would have great potential to evaluate the quality of 3D braided composites. 展开更多
关键词 3D braided composite dual-tree complex wavelet packet transform(DT-CWPT) ultrasonic wave
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纯二维5/3小波变换及其在CT图像无损压缩中的应用 被引量:3
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作者 徐妮妮 张明明 汪剑鸣 《电信科学》 北大核心 2016年第6期73-82,共10页
小波变换在数字图像处理领域有着广泛的应用,其对图像的处理常采用行列分离处理方式,这种方式不能完全吻合人眼视觉特性。针对这一情况,构造了一种与人眼视觉特性更加吻合的纯二维小波变换处理方式。首先,由一维5/3小波滤波器组通过Mc C... 小波变换在数字图像处理领域有着广泛的应用,其对图像的处理常采用行列分离处理方式,这种方式不能完全吻合人眼视觉特性。针对这一情况,构造了一种与人眼视觉特性更加吻合的纯二维小波变换处理方式。首先,由一维5/3小波滤波器组通过Mc Clellan变换构造纯二维5/3小波滤波器组,并用提升格式实现;然后,用该提升格式与纯二维Lazy小波滤波器组相嵌套的形式实现图像的纯二维5/3小波变换。为了便于工程应用,给出了其变换规程。将纯二维5/3小波变换用于CT图像的无损压缩,实验证明:对于512 dpi×512 dpi尺寸的CT图像,纯二维5/3小波变换无损压缩效果高于二维可分离5/3小波变换,每幅图像可平均节省1 989.9 byte。 展开更多
关键词 人眼视觉系统 McClellan变换 提升格式 纯二维5/3小波变换 无损压缩
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3,5-二甲基吡唑对尿素氮转化及NO_3^--N淋溶的影响 被引量:19
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作者 孙志梅 武志杰 +1 位作者 陈利军 于德清 《环境科学》 EI CAS CSCD 北大核心 2007年第1期176-181,共6页
采用室内培养和田间试验相结合的方法,探讨了新型硝化抑制剂3,5-二甲基吡唑(DMP)对尿素氮转化及玉米田硝酸盐淋溶损失的影响.结果表明,DMP对尿素水解仅起短暂的抑制作用,但可在较长时间内显著抑制土壤铵的氧化,且随DMP用量的增加,抑制... 采用室内培养和田间试验相结合的方法,探讨了新型硝化抑制剂3,5-二甲基吡唑(DMP)对尿素氮转化及玉米田硝酸盐淋溶损失的影响.结果表明,DMP对尿素水解仅起短暂的抑制作用,但可在较长时间内显著抑制土壤铵的氧化,且随DMP用量的增加,抑制效应显著增强.培养第10 d时,DMP各处理(0.002 5、0.01及0.025 g/kg)的土壤NH4+-N累积量分别比CK提高了5.17、9.36和11.04倍,而NO3--N累积量于培养第14 d时差异最大,与CK相比分别降低了33.30%、61.19%和73.72%(p<0.01).土壤NO2--N只在尿素施用前期有少量累积,但第3 d DMP各处理土壤NO2--N含量降低幅度达95.77%~96.13%;土壤矿质氮总量于10 d以后,随DMP用量的增加,显著降低,而DMP1处理的土壤微生物量N在培养14~56 d期间显著提高.连续2 a的玉米田间试验原位取土测定结果表明,2004和2005年,DMP的施用使作物根系密集层以下(40~100 cm)土层的NO3--N累积总量分别比CK降低了28.77%和44.70%.因此,硝化抑制剂DMP与尿素配合施用是调控氮素转化、缓解氮肥污染的有效措施. 展开更多
关键词 3 5-二甲基吡唑 尿素氮 转化 硝酸盐氮 淋溶
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F3′5′H基因的克隆、表达载体构建与矮牵牛遗传转化 被引量:10
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作者 司爱君 祝建波 +1 位作者 李吉莲 邓福军 《西北农业学报》 CAS CSCD 北大核心 2008年第5期306-309,329,共5页
类黄酮3′5′羟基化酶(Flavonoid-3’,5-’hydroxylase;F3′5′H)是花色素苷代谢途径中的一个关键性酶,能使花色素的合成趋向于形成蓝色的飞燕草色素。从蓝紫色矮牵牛的花瓣中提取总RNA,利用RT-PCR技术克隆得到了约1.7kb的F3′5′H片段... 类黄酮3′5′羟基化酶(Flavonoid-3’,5-’hydroxylase;F3′5′H)是花色素苷代谢途径中的一个关键性酶,能使花色素的合成趋向于形成蓝色的飞燕草色素。从蓝紫色矮牵牛的花瓣中提取总RNA,利用RT-PCR技术克隆得到了约1.7kb的F3′5′H片段。F3′5′H的cDNA序列分析结果表明,克隆得到的序列与原序列同源性达到99.34%,开放读码框为1 521 bp,编码507个氨基酸。将推算的氨基酸序列与NCBI登录的氨基酸序列进行分析比较,发现与文献报道的存在2个氨基酸差异,氨基酸同源率为99.6%。将此基因构建到含有35S启动子的植物表达载体PBI-F3′5′H上,并通过农杆菌介导法对粉红色矮牵牛进行了遗传转化,初步鉴定获得了转基因植株。 展开更多
关键词 矮牵牛 类黄酮35′羟基化酶基因 转化
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基于FPGA的La Gell5/3小波变换的硬件电路设计 被引量:2
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作者 侯宏录 姚恩源 《兵工自动化》 2013年第2期59-62,70,共5页
为了对冗余的图像数据进行有效的压缩,提出一种基于FPGA的快速小波变换的方案。介绍了La Gell 5/3提升小波变换的原理,设计了适用于高帧频CMOS相机的La Gell 5/3提升小波变换硬件结构,采用Verilog硬件语言在QuartusII软件平台下对设计... 为了对冗余的图像数据进行有效的压缩,提出一种基于FPGA的快速小波变换的方案。介绍了La Gell 5/3提升小波变换的原理,设计了适用于高帧频CMOS相机的La Gell 5/3提升小波变换硬件结构,采用Verilog硬件语言在QuartusII软件平台下对设计方案进行了实验,利用Matlab语言对图像进行反变换,并通过变换前与反变换后图像的比对,验证了算法的可行性。实验结果证明:该方案成功实现了基于FPGA的La Gell 5/3提升小波变换系统对给定图像的三级快速小波变换,相比较于DSP等硬件电路,更适合于高速图像实时处理的应用。 展开更多
关键词 LA Gell 5 3 FPGA 提升小波变换 高帧频相机
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5/3提升小波的FPGA动态RAM结构设计及其应用 被引量:3
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作者 宁永慧 郭永飞 +1 位作者 马天波 薛旭成 《液晶与显示》 CAS CSCD 北大核心 2013年第6期927-932,共6页
为了改善高分辨率TDICCD成像系统图像数据的高速传输特性,设计了FPGA内部实现5/3提升小波的动态RAM结构。该结构通过循环利用同一RAM资源进行图像数据的同时读写,解决了5/3提升小波在FPGA实现过程中的RAM不足问题,提高了RAM资源利用的... 为了改善高分辨率TDICCD成像系统图像数据的高速传输特性,设计了FPGA内部实现5/3提升小波的动态RAM结构。该结构通过循环利用同一RAM资源进行图像数据的同时读写,解决了5/3提升小波在FPGA实现过程中的RAM不足问题,提高了RAM资源利用的有效性。试验表明,5/3提升小波在FPGA内部的动态RAM实现过程,具有实时性高、可靠性好、占用资源较小等优点。该方法在图像预压缩、图像去噪、图像实时传输等方面有重要的意义。5/3提升小波在FPGA中的动态实现,完成了5行数据存储的提升小波处理过程,增强了星上实时数据的处理能力,为后续程序的开发奠定了基础。 展开更多
关键词 动态RAM 5 3提升小波 FPGA 时间延迟积分CCD
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类黄酮3',5'羟基化酶基因的克隆及转化铁炮百合 被引量:10
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作者 徐碧玉 刘菊华 金志强 《园艺学报》 CAS CSCD 北大核心 2005年第6期1051-1055,共5页
利用RT-PCR技术从矮牵牛的紫色花瓣中克隆了两个控制花色的类黄酮3,5羟基化酶基因Hf1和Hf2,并构建了植物表达载体,利用农杆菌介导法对铁炮百合进行了遗传转化,获得了转基因植株。
关键词 铁炮百合 类黄酮3 5’羟基化酶基因 转化
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二维离散5/3小波变换并行VLSI结构设计 被引量:1
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作者 杜会斌 周旭 +1 位作者 张学庆 吴晓娟 《无线电通信技术》 2006年第6期39-41,共3页
提出了一种基于提升算法的二维离散5/3小波变换(DWT)高效并行VLSI结构设计方法。该方法使得行和列滤波器同时进行滤波,采用流水线设计方法处理,在保证同样的精度下,大大减少了运算量,提高了变换速度,节约了硬件资源。该方法已通过了Veri... 提出了一种基于提升算法的二维离散5/3小波变换(DWT)高效并行VLSI结构设计方法。该方法使得行和列滤波器同时进行滤波,采用流水线设计方法处理,在保证同样的精度下,大大减少了运算量,提高了变换速度,节约了硬件资源。该方法已通过了VerilogHDL行为级仿真验证,可作为单独的IP核应用在JPEG2000图像编、解码芯片中。该结构可推广到9/7小波提升结构。 展开更多
关键词 二维离散5/3小波变换 VLSI 并行结构 提升方法
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5/3小波提升方法的FPGA仿真
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作者 董文辉 刘明业 《计算机工程》 CAS CSCD 北大核心 2004年第15期24-25,96,共3页
离散小波变换是当今许多图像处理和压缩技术的基础,并被最新的ISO/IEC静态图像压缩标准JPEG2000所采用。5/3小波提升方法在JPEG2000中主要用于无损图像压缩,该文为该算法提出一种硬件结构,并在FPGA上仿真实现。
关键词 小波变换 提升方法 5/3小波 流水线 FPGA
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天然产物5,6,7,3′,4′-五甲氧基异黄酮的合成(英文)
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作者 任宛莉 陈睿 +2 位作者 金叶 张韬 李洪启 《天然产物研究与开发》 CAS CSCD 2010年第6期956-960,共5页
以3,4-二甲氧基苯乙酸和3,4,5-三甲氧基苯酚为原料,通过一条包括酯化反应、Fries重排、以及Vilsmeier-Haack反应等5步反应的路线合成了天然产物5,6,7,3′,4′-五甲氧基异黄酮。根据3,4,5-三甲氧基苯酚计算目标产物的总收率为76%,利用NM... 以3,4-二甲氧基苯乙酸和3,4,5-三甲氧基苯酚为原料,通过一条包括酯化反应、Fries重排、以及Vilsmeier-Haack反应等5步反应的路线合成了天然产物5,6,7,3′,4′-五甲氧基异黄酮。根据3,4,5-三甲氧基苯酚计算目标产物的总收率为76%,利用NMR及元素分析确证了化合物的结构。 展开更多
关键词 5 6 7 3 4′-五甲氧基异黄酮 3 4 5-三甲氧基苯酚 FRIES重排 Vilsmeier-Haack反应 合成
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