噪声诱导下单热敏神经元信号检测

利用热敏神经元动作电位发放图、ISI分叉图、功率谱密度(PSD)等,系统地研究了单热敏神经元在噪声诱导下的随机共振现象.通过对比分析发现分岔周期数为1或者2的情况下,存在一最优输入信号频率fopt,使得神经元输出信噪比(rSNR)最高.不同噪声强度D下,热敏神经元对输人信号检测能力各异,低噪声强度下检测能力较好.     

整体拓扑性质的视知觉与计算

提出了一个早期视觉的可能的计算模型，把几何特征分为局部特征与全局特征，认为早期视觉中感知局部几何性质和全局拓扑性质先天运动感知，先于形状感知。模型本质上虽然仍然是读物上，但已不是的传统的ｖｏｎ Ｎｅｕｍａｎｎ的顺序计算，而是非ｖｏｎ Ｎｅｕｍａｎｎ的平行计算，它为计算理论和拓扑性质检测问题之间的矛盾提供了一个可能的解决方法。     

Common Fixed Points for Multiplicative Contractions in Multiplicative Metric Spaces

The study delves into multiplicative contractions, exploring the existence and uniqueness of common fixed points for a weakly compatible pair of mappings. Those mappings adhere to specific multiplicative contraction conditions characterized by exponents expressed as fraction multiplicative metric spaces. It is noted that a metric can induce a multiplicative metric, and conversely, a multiplicative metric can give a rise to a metric on a nonempty set. As an application, another proof of the exist...     

具有乘性色噪声的线性振荡器的随机共振

研究了具有耦合的两个乘性色噪声的欠阻尼线性振荡器的随机共振现象.基于线性系统理论,得到了平均输出幅度增益的精确表达式.分析表明,系统的输出幅度增益及增益的峰值高度是耦合噪声强度、这两种色噪声的强度和相关速率以及外场驱动频率的非单调函数.     

Ultimate physical limits to computation

Computers are physical systems: the laws of physics dictate what they can and cannot do. In particular, the speed with which a physical device can process information is limited by its energy and the amount of information that it can process is limited by the number of degrees of freedom it possesses. Here I explore the physical limits of computation as determined by the speed of light c, the quantum scale h and the gravitational constant G. As an example, I put quantitative bounds to the computational power of an 'ultimate laptop' with a mass of one kilogram confined to a volume of one litre.     

一类多乘积问题的全局优化方法

给出一类多乘积问题(P)的全局优化方法.首先将(P)转化为其等价问题(Q),利用变量代换,把(Q)写成(EQ)形式,然后建立(EQ)松弛线性规划(RLEQ),通过求解一系列线性规划问题,不断更新最优值的上下界,证明了所给算法的收敛性,数值实验表明算法是可行的.     

一类多乘积优化问题求解的新方法

利用所考虑问题的结构特点,提出一种新的线性化方法.该方法利用函数的二阶导数信息,线性化过程更为直接.为改善算法收敛速度,提出一个新的区域缩减准则.理论上证明了算法的收敛性,数值算例表明算法是有效可行的.     

乘积季节模型在商品房市场中的应用研究

主要采用时间序列乘积季节模型(随机季节模型与ARIMA模型的结合式)及多元统计方法,对商品房市场的发展规律进行了研究.通过对合肥市2001年至2005年60个月份的月度商品房销售面积进行实证分析,建立了一个商品房市场销售规律的统计预测模型ARIMA(0,1,1)×(0,1,1)12,并对该模型进行适应性检验,得到较好的结果.最后,利用该模型对该市的房地产发展趋势进行了预测.     

Using evolutionary computation to solve problems in nonparametric regression

This paper studies evolutionary mechanism of parameter selection in the construction of weight function for Nearest Neighbour Estimate in nonparametric regression. Construct an algorithm which adaptively evolves fine weight and makes good prediction about unknown points. The numerical experiments indicate that this method is effective. It is a meaningful discussion about practicability of nonparametric regression and methodology of adaptive model-building. Supported by the National Natural Science Foundation and 863 High Technology Project of China Ding Lixin: born in 1967, Ph.D. graduate student     

Using evolutionary computation to solve problems in nonparametric regression

This paper studies evolutionary mechanism of parameter selection in the construction of weight function for Nearest Neighbour Estimate in nonparametric regression. Construct an algorithm which adaptively evolves fine weight and makes good prediction about unknown points. The numerical experiments indicate that this method is effective. It is a meaningful discussion about practicability of nonparametric regression and methodology of adaptive model-building. Supported by the National Natural Science Foundation and 863 High Technology Project of China Ding Lixin: born in 1967, Ph.D. graduate student     

区间值度量空间的可乘性和连通性

给出了区间值度量空间的概念,根据一般拓扑学中积拓扑的定义,证明了可数多个区间值度量空间具有可乘性,讨论了区间值度量空间中的连通性。     

乘性与信号调制噪声在线性模型中的随机共振

研究了乘性噪声和信号调制噪声作用下一阶线性模型的随机共振现象.根据线性系统理论,利用噪声的统计特性,得到了系统输出幅度增益的解析表达式.研究发现,输出幅度增益是激励信号频率和系统参数的非单调函数,即出现了"真实的"随机共振和广义的随机共振现象;另外,输出幅度增益是噪声强度和噪声相关率的单调函数:随噪声强度的增大而增大,随噪声相关率的增大而减小.     

乘性噪声中的谐波恢复

研究在乘性噪声均值先验知识未知情况下的谐波恢复问题.提出了基于一阶、二阶循环统计量的混合方法(FSCSH)和基于一阶、三阶统计量的混合方法(FTCSH),即先利用一阶循环统计量得到对应非零均值乘性噪声的谐波频率,再求出与谐波频率对应的乘性噪声均值,最后用二阶或三阶循环统计量来恢复谐波.仿真结果证实了该方法的有效性.     

基于腔场中氮空穴色心的几何量子计算（英文）

利用纯几何操作,提出腔场中的氮空穴色心作为量子比特实现几何量子计算的方案.在暗态子空间中,选取合适的闭合演化回路,可以构造出单比特和双比特控制相位门.因此,该文提出了一种很有前景的实现容错量子计算的方案.     

Long-lasting sensitization to a given colour after visual search

Visual attention enables an observer to select specific visual information for processing. In an ambiguous motion task in which a coloured grating can be perceived as moving in either of two opposite directions depending on the relative salience of two colours in the display, attending to one of the colours influences the direction in which the grating appears to move. Here, we use this secondary effect of attention in a motion task to measure the effect of attending to a specific colour in a search task. Observers performed a search task in which they searched for a target letter in a 4 x 4 coloured matrix. Each of the 16 squares within a matrix was assigned one of four colours, and observers knew that the target letter would appear on only one of these colours throughout the experiment. Observers performed the ambiguous motion task before and after the search task. Attending to a particular colour for a brief period in the search task profoundly influenced the perceived direction of motion. This effect lasted for up to one month and in some cases had to be reversed by practising searches for the complementary colour, indicating a much longer-persisting effect of attention than has been observed previously.     

利用相关函数估计在图象光流计算中的误差

从光流来决定照相机与它所见的场景之间的相对运动，是一个困难的问题。不少人希望计算的误差能在一种可接受的范围内。然而，大部分光流研究用的是基于亮度不变假设的模型，而这种假设在不少情况下并不适用。当使用允许图象亮度改变的模型时，误差或者说偏差在图象光流计算中的性质，并利用一个各向同性的图象亮度的空间相关函数，估计在图象光流计算里的误差（偏差）。研究结果是：１）当亮度改变时，除非运动为零，在图象光流中存在误差；２）对较随机的图象来讲，图象光流中的误差比光滑图象中的误差更大；３）利用定义的相关函数，可能定量地估计在图象光流计算中的误差。     

带指数的多乘积约束下多项式函数的全局最优解

对广泛应用于金融、证券投资等实际问题中的带指数的多项式函数的极小值问题(P1)提出了一种有效的全局优化算法.从理论上证明了本算法的收敛性,数值实验表明提出的方法是可行和有效的.     

一类多乘积分式规划问题的全局优化算法

首先利用对数函数和指数函数的凹凸性构造目标函数的线性下界函数,从而建立问题(P)的松弛线性规划,然后给出求解问题(P)的分支定界算法。最后数值算例表明算法是可行的。     

具有乘法噪声的单模激光模型的系统消去程序

用Schner和Haken建立的系统消去法和系统绝热近似法对两种具有乘法噪声的单模激光模型进行研究,分别得出了其Ito形式和Stratonovich形式的序参量方程,并对随机序列z_t~(v)的统计性质进行了计算.最后,定性地分析了Ito形式和Stratonovich形式不等价的原因.     

相关乘性和加性噪声背景下的二维谐波恢复

针对乘性噪声和加性噪声均为零均值,且乘性噪声之间相关,乘性噪声和加性噪声之间也相关,这种复杂噪声背景下的二维谐波恢复问题,利用二维循环统计量方法进行了研究.提出了二维噪声互可混的概念,用来体现多个二维噪声之间的相关关系;定义了特殊的二维四阶时间平均多矩谱来估计信号频率.仿真实验证明了算法的有效性.