一种求解非线性方程组的混沌优化算法

本文针对非线性方程组的求解问题提出一种混合算法,将方程组转换成一个优化问题。利用优化问题的非线性共轭梯度法与混沌优化方法相结合,提出了一种新的混合优化算法。该算法能使非线性共轭梯度法跳出局部最优,最终获得全局最优。算法的收敛性也进行了证明,数值结果表明该算法是有效的。     

Study on the submerged fermentation (SMF) of termitomyces eurrhizus

The influence of KH\-2PO\-4, peptone and brown sugar on Termitomyces fuliginosu's mycelium formation was studied with the application of the design of quadratic rotation general combination based on determining the growth curve. A quadratic regression model of biomass to the doses of the above three factors was established. The model fit well and therefore the optimum fermentation condition was obtained. Responses of biomass to the three single factors and to their interactions were discussed. Thus, the highest level of biomass, 21.1 g/L, appeared under the optimized conditions when the initial KH\-2PO\-4, peptone and brown sugar were 1 g/L, 4 g/L and 72 g/L respectively.     

免疫算法与遗传算法的比较

免疫算法与遗传算法二者有不同点，通过仿真实验表明它们之间在功能和应用方面有区别．     

政府网站建设的影响因素分析及优化措施

通过对国内外政府网站的比较，提出了影响政府网站绩效优化的25个主要影响因素，并利用DEMATEL方法计算获得的原因度和中心度的数值辨识得到影响政府网站的主要因素为在线咨询、网站维护、信息服务、采购公开、财政公开、信息整合等，并根据主要因素提出了政府网站绩效优化的措施和建议。     

构建我国科学规范的公共财政支出体系的思考

本文从财政支出规模和结构两方面进行实证分析,揭示财政支出的"越位"与"缺位"现象依然大量存在,在此基础上提出,在公共财政的框架下,加大改革力度,增加财源,优化财政支出结构,重新构建适应公共财政要求的科学规范的支出体系。     

Application of response surface methodology in medium optimization for pyruvic acid production of <Emphasis Type="Italic">Torulopsis glabrata</Emphasis> TP19 in batch fermentation

Response surface methodology （RSM） was used to optimize the fermentation medium for enhancing pyruvic acid production by Torulopsis glabrata TP19. In the first step of optimization, with Plackett-Burman design, ammonium sulfate, glucose and nicotinic acid were found to be the important factors affecting pyruvic acid production significantly. In the second step, a 23 full factorial central composite design and RSM were applied to determine the optimal concentration of each significant variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. The optimum values for the critical components were obtained as follows： ammonium sulfate 0.7498 （10.75 g/L）, glucose 0.9383 （109.38 g/L） and nicotinic acid 0.3633 （7.86 mg/L） with a predicted value of maximum pyruvic acid production of 42.2 g/L. Under the optimal conditions, the practical pyruvic acid production was 42.4 g/L. The determination coefficient （R^2） was 0.9483, which ensures adequate credibility of the model. By scaling up fermentation from flask to jar fermentor, we obtained promising results.     

基于水平集方法的连续体结构拓扑优化方法研究

采用水平集方法描述结构的拓扑及其变化,使用紧支径向基函数对计算区域的水平集进行插值以得到参数化的水平集方法。针对给定体积约束下结构最小柔度的拓扑优化问题,推导了目标函数对插值系数的灵敏度及拓扑优化的迭代格式,数值计算表明,使用该方法进行结构拓扑优化得到的结果边界形状光滑连续且计算稳定性较好。     

理工类院校英语专业课程设置优化研究

通过对英语专业学生进行问卷调查、访谈和跟踪访问等形式,发现了理工类院校英语专业在课程设置上存在诸多问题,如课程设置缺少特色,各学期课程缺乏合理安排,专业英语课程师资不足,教材缺乏特色,社会实践环节薄弱等,并提出相应的对策,以优化课程设置,满足就业市场对复合型英语专业人才的需求。     

损失规避下的指数跟踪问题及其粒子群算法求解

随着指数衍生产品日益受到重视,指数化投资组合常被传统的消极基金管理者或机构所采用,而用有限的资金按指数构成比例进行投资显然是不现实的,所以指数的最优误差追踪就显得更加重要。将追踪误差定义为证券投资组合收益率与所追踪的指数基准收益率之差的均值平方和的平方根,建立了基数约束（即总资产数不超过某个特定整数K）下考虑投资者损失规避决策偏好的跟踪误差最小化模型,并设计了一个粒子群算法求解模型。实际算例表明,所构建的模型和算法是有效的。     

数学建模优化程序设计与数学原理的综合运用

从符号与数值的转化、同余映射中的周期长度及分阶段执行程序等3个方面,以实际例子研究了如何在实践中运用数学原理来优化程序设计、节约运行时间,达到利于解决数学建模问题的目标。