A robust locating multi-optima approach for damage identification of plate-like structures

This paper proposes a robust optimization approach for multiple damage identification of plate-like structures. Different from traditional particle swarm optimizations (PSOs), a combined PSO and niche technique (NPSO) is proposed to solve multimodal optimization problems, with the full consideration of subswarm creation, merging and absorbing mechanism. As a hypersensitive parameter to damage, the curvature mode shape is adopted to construct the objective function. Case studies are conducted to investigate the effectiveness and robustness of the algorithm on multi-damage identification. Simulation results show that the proposed algorithm exhibits robust search performance on identifying damage locations accurately with good convergence behavior. It is hoped that this study can provide guidance on robust damage detection, especially when the structure is subject to multiple damages and external disturbances.     

基于生态位理论的城市空间优化策略研究——以增城市为例

土地利用担负着城市空间架构和空间优化的重要功能.从生态位的角度看,城市空间优化具有内在和外在两方面驱动力,分别是土地生态位扩充和土地生态位差.在内外两种驱动力的共同作用下,土地变化方向总是朝着效益最大化和生态适宜度最高的方向发展.根据土地生态位整体效益最大化原理,增城市城市空间优化应当采取以下策略:承接西南、充实中部、优化东部、平衡西部、联合南部、调控北部.     

从居民生活用能状况分析电力市场机会

本文根据对秦皇岛地区居民生活用能状况的调查 ,较全面地了解了居民目前生活用能品种、用能水平、用能结构、用能倾向等多方面的状况，在此基础上，认真分析了电力市场的机会，从而为制定开拓居民电力市场的策略提供参考性的依据。     

基于MaxEnt模型的怒江金丝猴潜在适生区预测

怒江金丝猴是最新发现的世界上第五种金丝猴,种群数量极少,为我国一级重点保护野生动物。为探究怒江金丝猴的适生状况,基于怒江金丝猴的现代地理分布使用MaxEnt模型预测其现代及未来气候条件下的潜在适生分布区,并使用ENMeval数据包对参数进行调整,采用受试者工作特征曲线和刀切法对预测结果进行检验。研究结果表明：在最优参数下,MaxEnt模型在预测怒江金丝猴的适生区时表现良好,AUC值达到0.9995。温度变化系数、最冷季度平均温度、最冷季度降水量和归一化植被指数是影响怒江金丝猴适生区分布的主导变量。现代气候条件下,怒江金丝猴的高适生区集中于怒江两岸的高黎贡山与怒山,面积为6207 km²;未来气候条件下,伴随全球变暖,怒江金丝猴在中国西南部的适生区向外扩散延伸至金沙江,各类型适生区面积均有所增加。     

城市发展的空间竞争机制

运用生态学研究的相关原理和城市地理学的成果，对城市形成和发展过程中的竞争机制作了初步研究，指出竞争发生于城市发展的全过程和各相关尺度，是系统有序性目标的调控手段。对竞争机制的认识和利用，有益于城市空间结构的优化和发展战略的确定     

Niche accumulation and hybridisation strategies in transition processes towards a sustainable energy system: An assessment of differences and pitfalls

This paper assesses two patterns in transition processes for using them as strategies towards a sustainable energy system, i.e., niche accumulation and hybridisation. Both play important but different roles in transitions. The expected success of these strategies depends on the innovation's history and the innovation context. The different strategies are illustrated with several examples from the energy domain.     

Prospects of fuel cell auxiliary power units in the civil markets

Auxiliary power units (APUs), i.e. devices designed to provide additional onboard power in vehicles, are believed to be an important entry point for fuel cell (FC) technology into commercial markets. Three technologies are under consideration for this market: solid oxide fuel cells (SOFCs), proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). By using the concept of total addressable, potential and capturable markets, this paper discusses the opportunities and challenges of fuel cell auxiliary power units (FC APUs). A number of conclusions can be drawn. As FC APUs do not offer increased fuel efficiency when meeting electrical demand while the main engine is used for propulsion (as opposed to idling), applications on board transit vehicles such as buses seem limited. Potential markets begin to open up in vehicles that either have a very large electricity demand due to many high-energy onboard functions, such as luxury limousines, or that require electrical power whilst stationary. Examples in the latter category include law enforcement vehicles, recreational vehicles, and most importantly heavy duty trucks. Volume and start-up time seem to be the major technical challenges hindering the market penetration of FC APUs. However, whilst the functional benefits of FC APUs over existing technologies are limited, the former must also be able to compete on a cost basis. The intense activities of APU manufacturers suggest a confidence either in the potential for cost reductions or in the consumers’ willingness to pay. Similarly, the involvement of a number of big truck manufacturers casts doubt on the extent to which incumbents are taken by surprise by competence-destroying, disruptive and radical technologies like FC APUs.     

基于量子遗传和核模糊聚类的低压台区户变关系识别

户变关系对于营配融合、线损分析等业务的开展具有重要作用。为了得到准确的户变关系,本文提出一种基于量子遗传和模糊聚类的户变关系识别方法。主要思想为：由于不同台区电能表的电压过零偏移特征不同,采用核模糊C均值聚类对电能表电压的过零偏移进行分类,通过与变压器端的过零偏移比较,实现户变关系识别。首先,为了提高聚类精度和效率,采用量子遗传算法对模糊C均值聚类的聚类中心和核参数进行优化,并提出一种基于类间距离和类内距离的适应度函数构造方法。另外,为了解决遗传算法易陷入局部极值的问题,分别引入小生境协同进化策略、动态调整策略、Hadamard门变异策略,提高算法寻优能力。其次,通过对benchmark函数和UCI数据集特征的仿真测试,验证了本文提出方法比标准核模糊C均值聚类具有更高的聚类精度和运算效率。最后,采用本文方法对实际的台区变压器和电能表数据进行归属识别,结果表明,本文提出方法得到的结果与真实户变关系一致,具有较好的应用效果。     

基于小生境粒子群优化的挖掘机器人自抗扰视觉伺服控制

为提高挖掘机器人的自主挖掘能力,设计一种基于图像的自抗扰视觉伺服控制器,对挖掘机器人的动臂、斗杆、铲斗组成的3节机械臂末端位置和姿态在x-z平面进行控制,实现自主挖掘目标任务。针对自抗扰控制器需要整定的参数较多,参数间相互影响,整定困难的特点,引入粒子群算法对控制器参数进行优化。由于原始粒子群算法存在后期易陷入局部最优的缺欠,采用小生境粒子群算法对自抗扰控制器参数进行整定优化。对粒子群及小生境粒子群算法的优化性能进行比较研究的基础上,设计了适合挖掘机器人的自抗扰视觉伺服控制器,采用小生境粒子群算法得到自抗扰控制器整定参数。搭建xPCTarget主机—目标机环境进行试验及仿真,表明小生境粒子群优化的自抗扰视觉伺服控制器控制精度高、鲁棒性强。     

当心新的"信息化陷阱"——合理规划、慎重选择"信息化"切入点

信息化巳成为当今的一大热点，文章以客观的角度分析了企业信息化应用的现状，阐述了如何合理规划、选择“信息化”切入点，对待实施信息化的企业具有重要的意义。