Study on the Stock Price Index Forecasting Model Based on Optimized Neural Network

从19世纪建立以后，股票市场的涨跌已经成为反映一个国家国民经济的重要指标。它的作用不仅被政府部门所重视，也成为了广大投资者的关注对象。股票价格的变化和未来发展趋势对投资者来说是非常重要的。对股价预测越准确，投资者就能在风险较小的情况下获得较大的利润。股票市场的变化对于国家的国民经济发展和现代化建设也具有举足轻重的作用。因此对股票价格的预测研究，不仅有利于投资者掌握科学的投资方法，帮助投资者进行科学理性的投资，使投资者在风险最小的情况下获得最大的收益，而且在宏观层面上也具有重大的理论意义和诱人的应用前景。 本文以股票价格预测分析为研究的出发点，以广泛应用于预测实践的BP神经网络技术为基础，探讨...Since it was established in the 19th century, the stock market has become an important index of national economy. Its effect is not only valued by the government, but also by the majority of the investors. For stock investors, the more accurate of the trend of the future stock price forecasts, the safer of access to the profit and risk aversion; as for the national economic development and financi...学位：管理学硕士院系专业：管理学院管理科学系_管理科学与工程学号：1772009115093

碳纳米管的Ames试验研究

目的应用Ames试验系统观察多壁碳纳米管的诱变活性。方法选用TA97、TA98、TA100、TA102标准测试菌株,采用标准平板掺入法检测多壁碳纳米管的诱变活性。加S9混合液作为体外代谢活化系统。结果多壁碳纳米管在S9活化和非活化两种测试条件下,1～500μg/皿浓度范围,诱发TA98、TA100两种测试菌株回变菌落数与阴性对照组相比无明显增加,在1～10μg/皿浓度范围,诱发TA97和TA102产生的回变菌落数与阴性对照相比无明显增加,在10～500μg/皿测试浓度范围,对TA97和TA102产生的回变菌落数与阴性对照相比均达到阴性对照两倍以上。结论多壁碳纳米管具有碱基置换及移码型的直接诱变特性和间接诱变特性

Optimization Design of the Muffler Based on GT-power

为了寻求一种更简单有效的消声器设计方法,以某一型号发动机为例,将传统的消声器设计理论与gT-POWEr仿真软件相结合,构建了基于gT-POWEr的消声器优化设计流程.利用gT-POWEr软件的声学和流体仿真功能对各消声器结构方案进行仿真分析,通过比较消声器的插入损失和压力损失,得出较优方案,然后再对特定方案进行正交试验以获取最优参数组合,并以试验进行验证.结果表明,优化后的消声器的消声量增加了约12db.In order to seek a simpler and more effective muffler design method,take an engine as an example,the design optimization process based on GT-power was built by combining the traditional muffler design theory with GT-power simulation software.First,the simulation analysis about the structure of each muffler was carried out by using acoustic and fluid simulation function of the GT-power.Then,the optimal solution was obtained by comparing muffler insertion loss and pressure loss.Last,conduct orthogonal experiment for specific schemes to obtain the optimal parameters,which were verified by the test.The result showed that noise elimination quantity of the optimized muffler increased about 12 dB.国家科技支撑计划项目(2013BAF07B04); 科技部创新方法工作专项(2011IM020400); 福建省高校产学研合作科技重大项目(2011H6024