模糊理论在系统故障诊断中的应用

论文简单介绍了系统模糊故障诊断的基本原理,对模糊理论在系统故障诊断领域中的应用进行了分类介绍,并进一步分析了模糊故障诊断现存的一些问题,最后对它的发展作了展望.     

车辆智能悬挂发展现状与研究思路探讨

在分析车辆各类智能悬挂系统实现方案及技术特点的基础上,提出了基于路面预瞄的电磁混合悬挂技术是未来车辆智能悬挂技术的发展方向与研究主线,而路面不平度预瞄技术-电磁混合悬挂技术-复合控制方法与高效算法是车辆智能悬挂走向实用必须克服的3个关键技术.     

固定化复合酵母生产黍米黄酒的新工艺

以黍米为原料 ,采用固定化复合酵母细胞技术发酵生产黄酒 ,确定了最佳工艺条件 :固定化复合酵母细胞接种配比为酿酒酵母∶产酯酵母 =3∶2 ;固定化复合酵母载体填充率 8% ;发酵温度2 0℃ ;发酵时间 96h ;起始 pH4 0。在该条件下发酵生产的黄酒 ,口感风味较好 ,在缩短了发酵时间的同时总氨基氮和总酯含量较传统工艺都有了较大的提高。     

混合C=9制备壬基酚的研究

研究了以强酸性阳离子交换树脂为催化剂，以混合C9^=为原料制备壬基酚的工艺条件及树脂的再生方法，并考察了催化剂及再生剂的使用寿命。结果表明，混合C9^=可用于制备壬基酚，在110℃、苯酚与C9^=物质的量比为2．5、催化剂与C9^=质量比为30％的条件下连续反应64h，C9^=平均转化率达到85．9％，催化剂可反复多次再生使用，并具有较长的使用寿命。     

一类混合延迟混沌神经网络的同步

时滞混沌神经网络系统是解空间为无穷维系统,可生成多个正向Lyapunov指数,产生具有高度随机性和不可预测性的混沌甚至超混沌序列,这种特性使得时滞混沌神经网络系统特别适用于保密通信中,混沌同步是保密通信中的关键技术。基于Lyapunov稳定性理论和线性矩阵不等式(LMI)方法,研究了一类具有时变延迟和分布式延迟的混沌神经网络系统的同步问题,考虑系统的内部参数不确定性和外部干扰及混合时滞等因素,将系统时滞项加入所设计的控制器中,给出了保证误差系统的全局均方渐近稳定的充分条件和控制律,实现驱动系统和响应系统的同步。与其它方法相比,所设计的含有时滞项的控制器提高了系统误差精度及反应速率。最后,通过仿真实例,验证了所提方法的有效性。     

实时机模型及时间语义指令集研究

混合关键系统中,具有不同安全和时间关键度的应用程序共享计算资源.由于系统中存在多种不确定性,设计者需要能同时满足功能行为确定性、时间行为可预测性和高计算性能等多重设计约束的紧致时间设计方法,对现有计算机体系结构及编程语言的理论和方法提出了新的挑战.提出支持时间语义的实时机模型RTM和时间触发指令集TTI,作为构建多层次...     

Use of grape by‐product as a source of dietary fibre and phenolic compounds in sourdough mixed rye bread

The study evaluated the effect of grape by‐products (GP) on the chemical composition, soluble (SDF) and insoluble (IDF) dietary fibre, phenolic compounds and antioxidant activity (AA) and organoleptic characteristics of sourdough mixed rye bread. The following samples of sourdough mixed rye bread were prepared: control bread (BC) and breads with GP at four different levels: 4%, 6%, 8% and 10%. Addition of GP significantly improves dietary fraction contents, as bread with a 10% addition of GP accounts for 39% and 37% higher contents of IDF and SDF than BC. The assay of radical‐scavenging activity and reducing ability showed that GP addition greatly enhanced antioxidant properties of mixed rye breads. Profiles of phenolic compounds of supplemented breads were dominated by procyanidin B1 and B2, catechin, epicatechin, caffeic acid and myricetin. With an increase in the level of GP, the hardness and gumminess of the bread significantly increase. Although both BC and supplemented breads showed common volatile compound profiles, there were slight differences in the concentrations of those components. Sensory evaluation of GP‐enhanced breads revealed that a maximum of 6% GP could be incorporated to prepare acceptable products.     

Effects of pulse flow and leading edge sweep on mixed flow turbines for engine exhaust heat recovery

Recovery of heat energy from internal combustion engine exhaust will achieve significant road transportation CO2 reduction. Turbocharging and turbogenerating are most commonly used technologies to recover engine exhaust heat energy.Engine exhaust pulse flow can significantly affect the turbine performance of turbocharging and turbogenerating systems,and it is necessary to consider the pulse flow effects in turbine design and performance analysis.An investigation was carried out by numerical simulation on th...     

酪氨酸-溴酸钾-硫酸铈-丙酮-硫酸振荡体系的量热研究

采用量热法研究了封闭体系中酪氨酸-溴酸钾-硫酸铈-丙酮在酸性介质中的振荡行为。考察了各反应物初始浓度和温度对振荡周期tp,诱导期tind,诱导期放热Qind的影响。基于可逆的Oregonator模型和溴水解控制（BHC）模型,提出了一个包含17个动力学步骤和10个中间变量的混合模型,数值模拟的结果与实验结果具有较好的一致性。     

Markowitz-based portfolio selection with cardinality constraints using improved particle swarm optimization

This work presents particle swarm optimization (PSO), a collaborative population-based meta-heuristic algorithm for solving the Cardinality Constraints Markowitz Portfolio Optimization problem (CCMPO problem). To our knowledge, an efficient algorithmic solution for this nonlinear mixed quadratic programming problem has not been proposed until now. Using heuristic algorithms in this case is imperative. To solve the CCMPO problem, the proposed improved PSO increases exploration in the initial search steps and improves convergence speed in the final search steps. Numerical solutions are obtained for five analyses of weekly price data for the following indices for the period March, 1992 to September, 1997: Hang Seng 31 in Hong Kong, DAX 100 in Germany, FTSE 100 in UK, S&P 100 in USA and Nikkei 225 in Japan. The test results indicate that the proposed PSO is much more robust and effective than existing PSO algorithms, especially for low-risk investment portfolios. In most cases, the PSO outperformed genetic algorithm (GA), simulated annealing (SA), and tabu search (TS).