关键词： Land   americium   mathematical analysis   algorithms   Byways   iterative methods   Recursive   formula  

摘要： We present a detailed mathematical analysis of the original Retinex algorithm due to Land and McCann [J. Opt. Soc. Am. 61, 1 (1071)]. To this end, we propose an analytic formula that describes the algorithm behavior. More than one Retinex version (e.g., with and without threshold) is examined. The behavior of Retinex varying the number of paths is predicted, and its recursive iterations are mathematically analyzed using the formula. The mathematical setting presented serves as a common ground for the various Retinex implementations. Its validity is confirmed by the tests on images that we have performed. (c) 2005 Optical Society of America.

关键词： mathematical modeling   genetic algorithms   insulin secretion   insulin kinetics   pancreatic hormones  

摘要： Direct measurement of hormones secretion and kinetics in glucose metabolism is not feasible in the clinical practice, being highly invasive. As their knowledge is important in the diagnosis of metabolic disorders, thanks to mathematical models based on non-invasive tests, estimation of hormones behaviour is obtained. Unfortunately, traditional model estimation can suffer for convergence problems, and it can be strongly dependent on the parameters initial value. To overcome these limitations, Genetic algorithms (GAs) were tested on a group of 49 subjects. The stochastic nature of GAs allowed overcoming the initialization problem. Moreover, GAs significantly improved the accuracy of fit. (c) 2004 Elsevier Ltd. All rights reserved.

关键词： bacteriocin   Differential Evolution   Lactococcus lactis   temperature profile  

摘要： The effect of pH and temperature on cell growth and bacteriocin production in Lactococcus lactis C7 was investigated in order to optimize the production of bacteriocin. The study showed that the bacteriocin production was growth-associated, but declined after reaching the maximum titer. The decrease of bacteriocin was caused by a cell-bound protease. Maximum bacteriocin titer was obtained at pH 5.5 and at 22 degrees C. In order to obtain a global optimized solution for production of bacteriocin, the optimal temperature for bacteriocin production was further studied. Mathematical models were developed for cell growth, substrate consumption, lactic acid production and bacteriocin production. A Differential Evolution algorithm was used both to estimate the model parameters from the experimental data and to compute a temperature profile for maximizing the final bacteriocin titer and bacteriocin productivity. This simulation showed that maximum bacteriocin production was obtained at the optimal temperature profile, starting at 30 degrees C and terminating at 22 degrees C, which was validated by experiment. This temperature profile yielded 20% higher maximum bacteriocin productivity than that obtained at a constant temperature of 22 degrees C, although the total amount of bacteriocin obtained was slightly decreased.

关键词： MATHEMATICAL analysis   ALGORITHMS   MAGNETOSTATICS   INVERSION (Geophysics)   INTEGRAL equations   FUNCTIONAL equations   MAGNETIC susceptibility  

摘要： An algorithm for applying the method of integral equations to calculations of a 3D inverse problem of magnetostatic flaw detection is described.

关键词： coordinate transformation   Lagrange   Cartesian coordinates   geodetic coordinates  

摘要： The algorithm to transform from 3D Cartesian to geodetic coordinates is obtained by solving the equation of the Lagrange parameter. Numerical experiments show that geodetic height can be recovered to 0.5 mm precision over the range from -6 x 10(6) to 10(10) m.

关键词： 数据采集   统一数学模型   计算法   垂足计算法   正交内插法  

摘要： 总结数字测图数据采集中计算法的计算公式,建立一个统一的数据采集计算法的数学模型,以利于程序编制,也利于理解与记忆。

摘要： 本文讨论NP困难排序问题数学规划松弛算法，考虑的排序模型是工件可拒\n绝排序与工件加工时间可控排序。\n第一章总结了数学规划松弛方法设计排序问题近似算法的发展情况，其中包\n括线性规划松弛、凸二次规划松弛与半定规划松弛，所牵涉的排序问题有单台机\n器问题1|rj|∑wjCj、1|rj,pmtn|∑wjCj、1|prec|∑wjCj、1|rj,prec|∑WjCj、1|rj,prec,pmtn|\n∑WjCj，以及平行机问题R|rij|∑WjCj、R|rj,pmtn|∑WjCj、P|rj,prec|∑WjCj和加工时间\n可控问题R|cpt|∑WjCj。\n第二章我们研究工件可拒绝排序。第一节中我们对于工件具有优先关系、工\n件具有就绪时间的排序问题分别引入不同的表示工件是否被拒绝加工的0-1决策\n变量，应用线性规划松弛方法设计了求解排序问题1|rej|∑j∈-Sej+∑j∈SwjCj的\n3-近似算法、求解排序问题1|rej，prec|∑j∈-Sej+∑j∈SwjCj的4-近似算法与3.165-\n近似算法以及求解排序问题1|rej,prec,rj|∑j∈-Sej+∑j∈SwjCj的(3+√3)-近似算\n法。第二节中我们将排序问题1|rej|∑j∈-Sej+∑j∈SwjCj松弛为凸二次规划与凸\n规划，得到随机2-近似算法与随机3/2-近似算法，将工件具有就绪时间的排序问\n题1|rej，rj|∑j∈-Sej+∑j∈SwjCj松弛为凸二次规划，得到随机2-近似算法。\n第三章我们研究工件加工时间可控排序，工件加工时间的控制形式是\nPij=pij-tij。第一节中我们讨论工件加工时间是离散的可控排序问题\nP|dis_cpt,pmtn|n∑j=1cjtj+Cmax，应用线性规划松弛方法设计了求解这一排序问题\n的2-近似算法，以及应用随机化算法设计了求解这一排序问题的1.583-近似算\n法。在第一节中我们还讨论了工件具有优先关系的可控排序问题\n1|cpt,prec|n∑j=1cjtj+n∑j=1wjCj，应用线性规划松弛方法得到了求解这一排序问题的\n4-近似算法。在第二节中我们应用凸二次规划松弛方法讨论工件加工时间可控排\n序问题R|dis_cpt,ri,j |m∑i=1n∑j=1ci，jti,j+n∑j=1wjCj与R|cpt,ri,j|m∑i=1n∑j=1ci,jti,j+n∑j=1wjCj，分\n别得到随机2-近似算法与随机3-近似算法。\n关键词：排序，线性规划，凸二次规划，松弛，工件可拒绝，加工时间可控

关键词： HECKE ALGEBRAS   REPRESENTATIONS   BASES  

摘要： We give a purely combinatorial algorithm for the computation of the decomposition matrices for Ariki-Koike algebras when the parameters are powers of the same root of unity. (c) 2004 Elsevier Inc. All rights reserved.

关键词： 网络信息发布   层次化   PLCH二叉树模型  

摘要： 针对网络信息层次化的问题进行研究,建立了信息结构体的简化数学模型,并根据此简化模型的次优方案求解,得出了网络信息层次化的次优算法,同时对最优算法和次优算法就其在实际问题中的性能进行了比较。

关键词： trigonometrical fitting   exponential-fitting   P-C methods   Schrodinger equation  

摘要： The new scheme developed in this paper is a new trigonometrically-fitted predictor-corrector (P-C) scheme based on the Adams-Bashforth-Moulton P-C methods. In particular, our predictor is based on the fifth algebraic order Adams-Bashforth scheme and our corrector on the sixth algebraic order Adams-Moulton scheme. We compared the efficiency of this new scheme against well known methods and the numerical experimentations showed that our scheme is more efficient, even when compared to methods that have been specially designed for the solution of the radial Schrodinger equation. (c) 2005 Elsevier Ltd. All rights reserved.