基于PSO的二级倒立摆LQR最优控制器设计

根据微粒群算法的随机性、快速性、易于实现性等优点,针对LQR在二级倒立摆最优控制设计过程中对加权矩阵Q、R选择的盲目性,研究了基于PSO的LQR最优控制器的设计方法,该方法利用PSO算法的启发式全局优化特点对Q、R阵进行寻优,然后得到状态反馈控制律K。并设计了基于该方法的二级倒立摆的最优控制器,通过和基于遗传算法的LQR最优控制器比较,仿真结果表明：该方法所设计的最优控制器能使系统的响应时间更快,超调量更小,对二级倒立摆的控制效果更理想。     

Genome-Wide Identification and Characterization of Soybean GmLOR Gene Family and Expression Analysis in Response to Abiotic Stresses

The LOR (LURP-one related) family genes encode proteins containing a conserved LOR domain. Several members of the LOR family genes are required for defense against Hyaloperonospora parasitica (Hpa) in Arabidopsis. However, there are few reports of LOR genes in response to abiotic stresses in plants. In this study, a genome-wide survey and expression levels in response to abiotic stresses of 36 LOR genes from Glycine max were conducted. The results indicated that the GmLOR gene family was divided into eight subgroups, distributed on 14 chromosomes. A majority of members contained three extremely conservative motifs. There were four pairs of tandem duplicated GmLORs and nineteen pairs of segmental duplicated genes identified, which led to the expansion of the number of GmLOR genes. The expansion patterns of the GmLOR family were mainly segmental duplication. A heatmap of soybean LOR family genes showed that 36 GmLOR genes exhibited various expression patterns in different tissues. The cis-acting elements in promoter regions of GmLORs include abiotic stress-responsive elements, such as dehydration-responsive elements and drought-inducible elements. Real-time quantitative PCR was used to detect the expression level of GmLOR genes, and most of them were expressed in the leaf or root except that GmLOR6 was induced by osmotic and salt stresses. Moreover, GmLOR4/10/14/19 were significantly upregulated after PEG and salt treatments, indicating important roles in the improvement of plant tolerance to abiotic stress. Overall, our study provides a foundation for future investigations of GmLOR gene functions in soybean.     

学习资源库知识服务模型研究

学习资源库是基于Web学习环境中的重要组成部分,针对现有学习资源库服务的不足,文章提出了学习资源库知识服务模型,系统的论述了学习资源库知识服务的类型、服务提供方式、构成要素、工作机制以及服务过程等,提出了以Agent为主要实现技术的学习资源库知识服务系统框架,为验证此模型与框架的有效性与可行性,构建了实验系统。实验结果表明知识服务的提供能够有效的提高学习资源库的利用率、教与学效果以及学习资源管理效率。     

数据库技术在学习资源库系统开发中的应用

本文以一个初步完成的计算机专业部分课程学习资源库设计为例,对于学习资源库建设中的数据库技术的应用进行了探讨。首先概述学习资源库的基本组成,然后详尽分析学习资源库的设计、开发、使用、维护的基本过程。     

Energy saving potential and strategies for electric lighting in future North European, low energy office buildings: A literature review

This article presents key energy use figures and explores the energy saving potential for electric lighting in office buildings based on a review of relevant literature, with special emphasis on a North European context. The review reveals that theoretical calculations, measurements in full-scale rooms and simulations with validated lighting programs indicate that an energy intensity of around 10 kWh/m² yr is a realistic target for office electric lighting in future low energy office buildings. This target would yield a significant reduction in energy intensity of at least 50% compared to the actual average electricity use for lighting (21 kWh/m² yr in Sweden). Strategies for reducing energy use for electric lighting are presented and discussed, which include: improvements in lamp, ballast and luminaire technology, use of task/ambient lighting, improvement in maintenance and utilization factor, reduction of maintained illuminance levels and total switch-on time, use of manual dimming and switch-off occupancy sensors. Strategies based on daylight harvesting are also presented and the relevant design aspects such as effects of window characteristics, properties of shading devices, reflectance of inner surfaces, ceiling and partition height are discussed.