求矩阵最小多项式的初等变换方法

分别给出计算矩阵的最小多项式和向量关于矩阵的最小多项式的初等变换方法 .     

期货套期保值最大概率与最小风险分析

研究套期保值的最大概率和最小风险问题 ,导出最大概率的套期比和最小风险的套期比 ,并且说明它们是一致的 .因此 ,所得到的套期比具有最大概率和最小风险这两大优点 .使投资者用这样的套期比进行套期保值 ,就可以最大概率保证其收益 ,并且使其风险最小 .     

服务员假期中以概率p进入的M/G/1排队系统的随机分解

该文研究M/G/1多重休假排队系统，其中在服务员休假中到达顾客以概率p(0≤p≤1)进入。通过引进“服务员忙期”和使用拉普拉斯变换或拉普拉斯— —司梯阶变换，我们获得队长瞬态分布的拉普拉斯变换和稳态分布的递推表达式，进一步得到稳态队长分布的随机分解和在特殊情况下相应的一些结果。     

Characterization of the Performance of Micro-Scanning Infrared Imager

According to the working mechanisms of micro-scanning imagery, an application-oriented analytical method of micro-scanning imager is proposed. Firstly, the sensitivity and resolution of infrared imaging system based on the micro-scanning are characterized respectively, and the modification of Minimum Resolvable Temperature Difference (MRTD) model due to the micro-scanning is implemented. A comparison of MRTD curve between the staring and micro-scanning imaging system is performed. Finally, the field performance of micro-scanning based infrared imaging system is predicted and discussed with the target acquisition model. The simulated results show whether micro-scanning improve the infrared imaging system performance depends on the other imaging system parameters, and working conditions.     

Theoretical analysis of crosstalk between oxygenated and deoxygenated haemoglobin in focal brain-activation measurements by near-infrared topography

The crosstalk between concentration changes in oxygenated haemoglobin and deoxygenated haemoglobin calculated by the modified Lambert-Beer law in near-infrared topography is theoretically investigated. The changes in intensity detected with probe pairs on the scalp caused by the concentration change in either oxygenated or deoxygenated haemoglobin induced by the focal brain activation is predicted by Monte Carlo simulation. The topographic images of the changes in oxygenated and deoxygenated haemoglobin are obtained from the changes in the intensity of light at two wavelengths detected by probe pairs to evaluate the crosstalk. The crosstalk slightly depends on the positional relationship between the probe arrangement and the focal brain activation and is minimised when the focal brain activation is located below a measurement point that is the midpoint between a probe pair. The 690-/830-nm wavelength pair is practically effective for reducing the crosstalk, especially the crosstalk from oxygenated haemoglobin to deoxygenated haemoglobin, in the NIR topography.     

Predicting PH vibrations of gas phase molecules and surface‐adsorbed species using bond length‐frequency correlations

The high frequency XH (e.g., X = C, Si) stretching modes in small molecules are only slightly perturbed by other vibrational modes present in the system. The isolated frequencies, in these cases, exhibit a linear relationship with the corresponding bond lengths. Here, we study such a bond length‐frequency correlation in the case of PH stretching vibrations for molecules in the gas phase as well as for surface‐adsorbed species. Although a high degree of linear correlation is found, there is a small dependence on the local coordination around P, leading to significant deviations in some cases. By a careful analysis, we show that such correlations can be used to predict new surface frequencies without computing the Hessian matrix explicitly. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009     

Study of the sodium dodecyl sulphate–protein complexes: evidence of their wormlike conformation by treating them as random coil polymers

The Kuhn statistical segment length, A, was determined for the sodium dodecyl sulphate (SDS)–protein complexes in two binding levels of SDS adsorbed onto the protein. These complexes are treated as random coil polymers. For the SDS–protein complex of binding level 1.4 g SDS per gram of protein, the value of A was found equal to 76 and 37 Å in 0.01 and 0.1 M ionic strength, correspondingly. For the complex of binding level 0.4 g SDS per gram of protein, the value of A was found equal to 30 Å. The calculation was based mainly on two equations (Eqs. 4 and 5; Dondos and Benoît, Polymer 18:1161, 1977; Dondos and Staikos, Colloid Polym Sci 273:623, 1995, correspondingly). Our findings are supported by gel permeation chromatography results, drawn according to the “modified universal calibration” and suggest that these complexes should be considered as wormlike polymers presenting a considerable draining effect.     

A markov-modulated M/M/1 queue with group arrivals

We study anM/M/1 group arrival queue in which the arrival rate, service time distributions and the size of each group arrival depend on the state of an underlying finite-state Markov chain. Using Laplace transforms and matrix analysis, we derive the results for the queue length process, its limit distribution and the departure process. In some special cases, explicit results are obtained which are analogous to known classic results.     

Analysis of the asymmetric shortest queue problem

In this paper we study a system consisting of two parallel servers withdifferent service rates. Jobs arrive according to a Poisson stream and generate an exponentially distributed workload. On arrival a job joins the shortest queue and in case both queues have equal lengths, he joins the first queue with probabilityq and the second one with probability 1 −q, whereq is an arbitrary number between 0 and 1. In a previous paper we showed for the symmetric problem, that is for equal service rates andq = 1/2, that the equilibrium distribution of the lengths of the two queues can be exactly represented by an infinite sum of product form solutions by using an elementary compensation procedure. The main purpose of the present paper is to prove a similar product form result for the asymmetric problem by using a generalization of the compensation procedure. Furthermore, it is shown that the product form representation leads to a numerically efficient algorithm. Essentially, the method exploits the convergence properties of the series of product forms. Because of the fast convergence an efficient method is obtained with upper and lower bounds for the exact solution. For states further away from the origin the convergence is faster. This aspect is also exploited in the paper.     

液体闪烁体衰减长度和光产额的测量

简要介绍了用于反应堆中微子实验的液体闪烁体的成分, 描述了液闪衰减长度和光产额的测量原理、方法、装置及过程, 给出了不同配比的液闪的光产额和衰减长度的测量结果, 并对液闪光产额和衰减长度的性能及影响因素进行了研究. 测量结果表明, 这些液闪可以满足中微子实验的需求.