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11.
Two-dimensional (2-D) adaptive filtering is a technique that can be applied to many image processing applications. This paper will focus on the development of an improved 2-D adaptive lattice algorithm (2-D AL) and its application to the removal of correlated clutter to enhance the detectability of small objects in images. The two improvements proposed here are increased flexibility in the calculation of the reflection coefficients and a 2-D method to update the correlations used in the 2-D AL algorithm. The 2-D AL algorithm is shown to predict correlated clutter in image data and the resulting filter is compared with an ideal Wiener-Hopf filter. The results of the clutter removal will be compared to previously published ones for a 2-D least mean square (LMS) algorithm. 2-D AL is better able to predict spatially varying clutter than the 2-D LMS algorithm, since it converges faster to new image properties. Examples of these improvements are shown for a spatially varying 2-D sinusoid in white noise and simulated clouds. The 2-D LMS and 2-D AL algorithms are also shown to enhance a mammogram image for the detection of small microcalcifications and stellate lesions.  相似文献   
12.
Kong  S.K. Ku  W.H. 《Electronics letters》1996,32(12):1052-1054
A chopper stabilised ΠΔΣ ADC architecture is proposed. A chopper stabilised version of ΠΔΣ ADC, which has identical performances to the regular ΠΔΣ ADC but is immune to low frequency noises such as DC offsets, can be obtained without adding hardware complexities  相似文献   
13.
This paper investigates the impact of source/drain impedance, gate-to-bulk capacitance, and gate resistance on device properties from 0 to 50 GHz for 0.13-/spl mu/m MOSFETs. Better device characteristics (g/sub m/ and C/sub gg/) can be found on MOSFETs with lower metal (or source/drain) resistance. But the best frequency characteristics (f/sub T/ and f/sub max/) occurred on MOSFETs with medium metal (or source/drain) resistance due to the increased interconnection capacitances. For radio frequency MOSFETs with finger-gate structure, better high-frequency behavior occurred on devices with medium finger-gate width W/sub f/ because of the tradeoff between gate (or source/drain) resistance and parasitic capacitance.  相似文献   
14.
Thermoacoustic tomography (TAT) is an emerging imaging technique with great potential for a wide range of biomedical imaging applications. In this paper, we propose and investigate reconstruction approaches for TAT that are based on the half-time reflectivity tomography paradigm. We reveal that half-time reconstruction approaches permit for the explicit control of statistically complementary information that can result in the optimal reduction of image variances. We also show that half-time reconstruction approaches can mitigate image artifacts due to heterogeneous acoustic properties of an object. Reconstructed images and numerical results produced from simulated and experimental TAT measurement data are employed to demonstrate these effects.  相似文献   
15.
This letter introduces an analytical model to represent line-edge roughness (LER) effects on both off-state leakage and drive current for sub-100-nm devices. The model partitions a given device into small unit cells along its width, each unit cell assumes a constant gate length (i.e., cell's width is small compared to LER spatial frequency). An analytical model is used to represent saturated threshold voltage dependency on the unit cell's gate length. Using this technique, an efficient and accurate model for LER effects (through Vts variations) on off-state leakage and drive current is proposed and experimentally validated using 193 and 248 nm lithography for devices with 80-nm nominal gate lengths. Assuming that the deviation from the ideal 0-LER case remains constant from generation to generation, the model predicts that 3 nm or less LER is required for 50-60-nm state-of-the-art devices in the 0.1-μm technology node. Based on data presented, we suggest that the LER requirement for this technology node is attainable with an alternated phase-shift type of patterning process  相似文献   
16.
在柔性变焦系统中的压力变焦镜   总被引:1,自引:1,他引:1  
张耀宁  库耕  程祖海  杜泽明  李锋 《中国激光》1998,25(11):998-1002
从理论上和实验上对水冷镜的镜面曲率半径随压力变化的规律作了研究。对压力变形后镜面相对于球面作了波像差分析,分析表明压力变焦镜用于中红外激光系统是合适的  相似文献   
17.
《EDA技术》作为电子信息类专业方向一门重要的专业基础课程,对培养大学生的创新实践能力具有重要的作用。分析了当前《EDA技术》课程的现状以及存在的教学弊端,提出以电子设计竞赛理念为主导,在教学理念、教学方法以及考核方法等方面提出了具体的改革措施。经过课堂教学实践证明,改革方法对于提高大学生学习的主动性和创造性,以及增强实践动手能力具有良好作用,对于提高电子设计竞赛的成绩具有明显的效果。  相似文献   
18.
The exotic photophysical properties of organic–inorganic hybrid perovskite with long exciton lifetimes and small binding energy have appeared as promising front‐runners for next‐generation non‐volatile flash photomemory. However, the long photo‐programming time of photomemory limits its application on light‐fidelity (Li‐Fi), which requires high storage capacity and short programming times. Herein, the spatially addressable perovskite in polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO)/perovskite composite film as an photoactive floating gate is demonstrated to elucidate the effect of morphology on the photo‐responsive characteristics of photomemory. The chelation between lead ion and PEO segment promotes the anti‐solvent functionalities of the perovskite/PS‐b‐PEO composite film, thus allowing the solution‐processable poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) to act as the active channel. Through manipulating the interfacial area between perovskite and P3HT, fast photo‐induced charge transfer rate of 0.056 ns?1, high charge transfer efficiency of 89%, ON/OFF current ratio of 104, and extremely low programming time of 5 ms can be achieved. This solution‐processable and fast photo‐programmable non‐volatile flash photomemory can trigger the practical application on Li‐Fi.  相似文献   
19.
Performance of different estimators describing propagation of electroencephalogram (EEG) activity, namely: Granger causality, directed transfer function (DTF), direct DTF (dDTF), short-time DTF (SDTF), bivariate coherence, and partial directed coherence are compared by means of simulations and on the examples of experimental signals. In particular, the differences between pair-wise and multichannel estimates are studied. The results show unequivocally that in most cases, the pair-wise estimates are incorrect and a complete set of signals involved in a given process has to be used to obtain the correct pattern of EEG flows. Different performance of multivariate estimators of propagation depending on their normalization is discussed. Advantages of multivariate autoregressive model are pointed out.  相似文献   
20.
本文以一个四十八台摄象机和四台监视器的系统为例,介绍一种由MCS-51系列单片机组成的光纤监控电视系统中心监控装置部件的设计考虑。  相似文献   
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