Charge distribution in homonuclear bonds: A semiempirical modeling

Atoms characterized by nonequivalent electronegativities form chemical bonds by exchanging electrical charge. The fraction of charge exchanged is dictated by the electronegativity differences among the system atoms. In the electronegativity equalization method, the charge distribution is estimated by forcing the system to relax to a common chemical potential, which corresponds to its configuration of energy minimum. By definition, this method cannot be applied to homonuclear bonds. A model is proposed to estimate the charge shared in molecular orbitals of homonuclear molecules. The model expands upon the electronegativity equalization method by adding formalism to describe the spin coupling characteristic of homonuclear bonds. Results are in excellent agreement with other quantum mechanical estimations of the charge distributions. © 2013 Wiley Periodicals, Inc.     

Feed-forward control of SOA gain for power equalization in optical burst switching networks

We evaluate the performance of a novel technique to equalize power variation between optical bursts using feed-forward control of semiconductor optical amplifier gain. The technique enables large dynamic range power equalization of incoming optical bursts with up to 10 dB power difference. Moreover, the technique can remove SOA-induced waveform distortion. We achieve more than 4 dB sensitivity improvement with equalized burst power.     

有理数谐波锁模光纤激光器中脉冲幅度的均衡

提出了一种在有理数谐波锁模光纤激光器中实现脉冲幅度均衡的新方法，让脉冲在腔内循环-圈中往复通过调制器两次，使调制器在腔内既作为锁模器件又作为脉冲幅度均衡器件。用时域分析的方法证明这种结构在调制器工作在其特性曲线的线性区时可以实现5阶以下有理数谐波锁模的脉冲幅度均衡。实验中在调制频率约2GHz时验证了理论分析的结果。     

基于模拟退火算法的盲均衡器设计

盲均衡技术是不需要训练序列的自适应均衡技术.该项技术可以消除由于通信信道失真造成的码间干扰.本文的目的是对盲均衡技术作一介绍,包括对广泛应用的最大归一化累积量判据的介绍和讨论,并在此基础上提出了基于模拟退火技术的设计方法,最后,对这种盲均衡器骑行了仿真,并得出了相应的结论.     

Perceptual contrast enhancement with dynamic range adjustment

Recent years, although great efforts have been made to improve its performance, few Histogram equalization (HE) methods take human visual perception (HVP) into account explicitly. The human visual system (HVS) is more sensitive to edges than brightness. This paper proposes to take use of this nature intuitively and develops a perceptual contrast enhancement approach with dynamic range adjustment through histogram modification. The use of perceptual contrast connects the image enhancement problem with the HVS. To pre-condition the input image before the HE procedure is implemented, a perceptual contrast map (PCM) is constructed based on the modified Difference of Gaussian (DOG) algorithm. As a result, the contrast of the image is sharpened and high frequency noise is suppressed. A modified Clipped Histogram Equalization (CHE) is also developed which improves visual quality by automatically detecting the dynamic range of the image with improved perceptual contrast. Experimental results show that the new HE algorithm outperforms several state-of-the-art algorithms in improving perceptual contrast and enhancing details. In addition, the new algorithm is simple to implement, making it suitable for real-time applications.     

具有不完全信息的内部交易动态博弈

在Kyle模型中的线性均衡假设进行了修正的基础上,针对内部交易者只具有资产价值不完全信息情况,建立两期风险厌恶型内部交易均衡模型,并求得该模型的子博弈纳什均衡解.由此发现资产价值不完信息中噪音对市场干扰程度愈小(波动程度愈小),就愈有利于内部交易者的收益;内部交易者的交易就愈活跃;交易均衡价格包含资产价值信息就愈多.     

输出功率动态均衡的WDM模块的分析与研制

研究了以MEMS衰减器为核心的节点光功率均衡方案,在此基础上,研制出了输出功率动态均衡的WDM模块。并对模块进行了测试,其主要性能指标都达到了设计要求。适合在光通信系统评估、WDM系统功率均衡等场合使用。