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1.
This paper is a selective review of the regularization methods scattered in statistics literature. We introduce a general conceptual approach to regularization and fit most existing methods into it. We have tried to focus on the importance of regularization when dealing with today's high-dimensional objects: data and models. A wide range of examples are discussed, including nonparametric regression, boosting, covariance matrix estimation, principal component estimation, subsampling.  相似文献   
2.
This paper describes a 10 bit 30 Msample/s (MSPS) CMOS analog-to-digital converter (ADC) for high-speed signal processing, especially for subsampling applications, for example digital video broadcasting over cable (DVB-C), terrestrial (DVB-T) and handheld (DVB-H) systems. The proposed pipelined ADC shows a good figure-of-merit (FoM). It adopts a power efficient amplifier sharing technique, a symmetrical gate-bootstrapping technique with modified timing for the bottom-sampling switch of a wideband sample-and-hold (S/H) circuit, a proposed stable high-swing bias circuit for a wide-swing gain-boosting telescopic amplifier. The measured differential and integral nonlinearities of the prototype in a 0.25-μm CMOS technology show less than 0.4 least significant bit (LSB) and 0.85 LSB respectively at full sampling rate. The ADC exhibits higher than 9 effective number of bits (ENOB) for input frequencies up to about 60 MHz, which is the fourfold Nyquist rate (fs/2), at 30 MSPS. The ADC consumes 60 mW from a 3-V supply and occupies about 1.36 mm2. Jian Li received the Bachelor of Engineering (B.E.) degree in electronic engineering from Xi’an Jiaotong University, Xi’an, China, in 2003. He is currently working toward the Ph.D. degree at Microelectronics department, Fudan University, Shanghai, China. His current research interest is high-speed high resolution A/D converter design. Xiaoyang Zeng was born in Hunan Province, P.R. China on April 17, 1972. He received the B.S. degree from Xiangtan University, China in 1992, and the Ph.D. degree from Changchun Institute of Optics and Fine Mechanics, Chinese Academy of Sciences in 2001. From 2001 to 2003, he worked as a post-doctor researcher at the State-Key Lab of ASIC & System, Fudan University, P.R. China. Then he joined the faculty of Department of Micro-electronics at Fudan University as an associate professor. His research interests include information security chip design, VLSI signal processing, and communication systems. Prof. Zeng is the Chair of Design-Contest of ASP-DAC 2004 and 2005, also the TPC member of several international conferences such as ASCON 2005 and A-SSCC 2006, etc. Jianyun Zhang received the B.S., M.S. and Ph.D degree in electrical engineering from Fudan University, Shanghai, China in 1997, 2000 and 2006 respectively. From 2000 to 2002, he was with Alcatel microelectronics, Belgium, where he was involved in circuit design for GSM and GPRS. In 2002, he joined Trident microsystem, where he concentrated on the design of Video AFE including data converters and mixed signal circuits. In 2005, he joined Shihong microelectronics Corp., where he is now a director of mixed signal IC for video high speed interface. His research interests include data conversion, HDMI SerDes, and analog circuit design. Lei Xie received the Bachelor of Science (B.S.) degree in microelectronics from Nankai University, Tianjin, China, in 2005. He is currently working toward the M.S. degree at Fudan University, Shanghai, China. His current research interest is high-speed high resolution A/D converter. Huan Deng received the B.S. degree in microelectronics from Fudan University, Shanghai, P.R. China, in 2003. He is currently working toward the M.S. degree in microelectronics at the State Key Lab of ASIC & System, Fudan University. He is currently involved in the design of low-power, high-speed PLL’s. Yawei Guo received the B.S. and M.S. degree in electrical engineering from Fudan University in 1999 and 2002 respectively. From 2002 to August 2003, he was with Philips Semiconductors in Shanghai. Since August 2003, he has been with Shanghai MicroScience Integrated Circuits Co., Ltd., based in Shanghai, P. R. China. He has been leading a group and developing analog and mixed signal circuits. His research interests include high-speed data communication, data converters, and phase locked loops.  相似文献   
3.
基于灰色理论的机电系统全寿命小子样系统研究   总被引:1,自引:0,他引:1  
描述了以机电系统全寿命序列为代表的时间序列混沌特性,分析了灰关联分析和GM模型在产品可靠性预测中可开拓贫信息的可行性,阐述了GM和BP方法在机电系统全寿命预测时的特长及缺陷,介绍了将灰色理论用于机电系统全寿命小子样系统研究取得的进展,并以3个工程实例进一步验证。旨在应用灰色理论对重大机电产品全寿命预测中的小样本开发有所突破。  相似文献   
4.
A comparison was made between dry milling and slurry mixing as a comminuting step preceding mycotoxin analysis. Sample schemes of up to 30 kg are mandated by European Commission legislation. Cocoa, green coffee, almonds and pistachio samples of 10 kg were milled by a Romer analytical sampling mill and all three subsamples were analysed for aflatoxin B1 or ochratoxin A content. The homogenization process was evaluated in terms of the analytical results, coefficients of variation for different mills and particle size distributions. Coefficients of variation for the comminuting step were higher for dry milling than for slurry mixing. This difference was explained based on measured particle size distributions for both milling types. Measurements also showed slight differences in mycotoxin content of samples based on milling procedures. This might lead to lots being wrongly accepted or rejected based on an erroneous subsample result. It was concluded that sample comminution was best performed by slurry mixing, which produced smaller particles and, consequently, homogeneous samples with lowest coefficients of variation. Additional data are given on analytical results in 10-kg subsamples that originate from the aggregate 30-kg sample as described in Commission Directive 98/53/EC.  相似文献   
5.
动态图象运动矢量多重跟踪搜索算法及实现   总被引:1,自引:0,他引:1  
针对动态图象运动矢量搜索过程中,使用普通的对数搜索方法有可能无法搜索到真实最优运动矢量的问题,分析了产生该问题的原因,并提出使用运动矢量多重跟踪方法进行运动矢量搜索。在图象匹配的过程中应用亚采样模板有效地降低了该方法的计算量。对大量数据的分析试验证实,该方法具有很好地适应多极点匹配图象的特点,能准确搜索到真实最优运动矢量点。  相似文献   
6.
计算机系统中的YUV   总被引:6,自引:2,他引:4  
简要介绍YUV色彩空间、取样原理、YUV格式以及与RGB的关系。  相似文献   
7.
在彩色图象传输、采集、存贮过程中,一般都采用对色度通道进行压缩的技术来减少图象占用的系统资源,在重建中,采用大面积着色的方法来重建图象。但这种方法会在图象的细节部分引入较大的误差,为了在实际应用中得到最佳的重建彩色图象,就需要研究在色度通道亚采样的情况下,如何利用了完备的数据有效地重建图象。针对CCD彩色图象的空间量化特点,提出了一种利用自然图象的约象条件和人眼视觉生理学特点重建CCD彩色图象的方法。该方法利用高分辩率的通道数据来获得图象的细节信息,并且利用图象各通道间的细节相似性(同变性)来获得低分辩率通道的图象细节。通过实验证明,该方法有效地提高了图象的清晰渡,消除了CCD图象重建中常见的伪彩和图象模糊等现象,可以用于数码相机或多光谱遥感图象处理等方面。  相似文献   
8.
This work presents an investigation of the bias error introduced in time of flight estimation realized by subsample interpolation in digital domain. The time of flight estimation is accomplished based on the evaluation of the peak position of the cross correlation function. In order to cope with the discrete nature of the cross-correlation function, subsample estimation exploits three time domain interpolation techniques: parabolic, cosine, Gaussian and frequency domain interpolation using phase angle. An empirical equation relating the maximum value of the bias error to sampling frequency and signal parameters (center frequency and envelope bandwidth) has been derived. It is found that the maximum value of the bias error is in inverse cubic relation to sampling frequency and in quadratic relation envelope bandwidth for cosine interpolation. The maximum value of the bias error is in inverse cubic relation to sampling frequency and in quadratic relation to center frequency and envelope bandwidth for parabolic interpolation. The coefficients related to the approximation technique are given. Results can be applied for bias errors estimation or correction when fast subsample interpolation is used and application of phase domain interpolation is unacceptable due to processing speed limitations. The equations for minimum required sampling frequency are derived by balancing the interpolation error against Cramer–Rao lower bound.  相似文献   
9.
针对多聚焦图像融合存在的问题,提出一种基于非下采样Contourlet变换(NSCT)的多聚焦图像融合新方法。首先,采用NSCT对多聚焦图像进行分解;然后,对低频系数采用基于改进拉普拉斯能量和(SML)的视觉特征对比度进行融合,对高频系数采用基于二维Log-Gabor能量进行融合;最后,对得到的融合系数进行重构得到融合图像。实验结果表明,无论是运用视觉的主观评价,还是基于互信息、边缘信息保留值等客观评价标准,该文所提方法都优于传统的离散小波变换、平移不变离散小波变换、NSCT等融合方法。  相似文献   
10.
林攀  陈健美  王远朋 《计算机工程》2014,(3):175-179,183
随着电子病历记录(EMR)系统在诸多医院的广泛使用,医生可以利用计算机云交互和共享医学数据,并通过下一代临床决策支持系统提取医学记录信息,从而做出精确诊断。为解决EMR系统传输过程中的医学信息泄露或纂改问题,将EMR系统中经过B++编码后的医学数据嵌入到病人的指纹中,通过基于非下采样Contourlet变换的数字水印算法,提取含有特征结构信息和注册密钥的指纹,并将其嵌入到病人的医学图像中,提高EMR系统医学信息的安全性。实验结果表明,该方法实现的医学水印图像具有较高的鲁棒性,并且由于允许高容量的医学信息嵌入,保证了医学数据的完整性。  相似文献   
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