Handling multiple objectives with biogeography-based optimization

Biogeography-based optimization (BBO) is a new evolutionary optimization method inspired by biogeography. In this paper, BBO is extended to a multi-objective optimization, and a biogeography-based multi-objective optimization (BBMO) is introduced, which uses the cluster attribute of islands to naturally decompose the problem. The proposed algorithm makes use of nondominated sorting approach to improve the convergence ability effciently. It also combines the crowding distance to guarantee the diversity of Pareto optimal solutions. We compare the BBMO with two representative state-of-the-art evolutionary multi-objective optimization methods, non-dominated sorting genetic algorithm-II (NSGA-II) and archive-based micro genetic algorithm (AMGA) in terms of three metrics. Simulation results indicate that in most cases, the proposed BBMO is able to find much better spread of solutions and converge faster to true Pareto optimal fronts than NSGA-II and AMGA do.     

MapReduce Workload Modeling with Statistical Approach

Large-scale data-intensive cloud computing with the MapReduce framework is becoming pervasive for the core business of many academic, government, and industrial organizations. Hadoop, a state-of-the-art open source project, is by far the most successful realization of MapReduce framework. While MapReduce is easy- to-use, efficient and reliable for data-intensive computations, the excessive configuration parameters in Hadoop impose unexpected challenges on running various workloads with a Hadoop cluster effectively. Consequently, developers who have less experience with the Hadoop configuration system may devote a significant effort to write an application with poor performance, either because they have no idea how these configurations would influence the performance, or because they are not even aware that these configurations exist. There is a pressing need for comprehensive analysis and performance modeling to ease MapReduce application development and guide performance optimization under different Hadoop configurations. In this paper, we propose a statistical analysis approach to identify the relationships among workload characteristics, Hadoop configurations and workload performance. We apply principal component analysis and cluster analysis to 45 different metrics, which derive relationships between workload characteristics and corresponding performance under different Hadoop configurations. Regression models are also constructed that attempt to predict the performance of various workloads under different Hadoop configurations. Several non-intuitive relationships between workload characteristics and performance are revealed through our analysis and the experimental results demonstrate that our regression models accurately predict the performance of MapReduce workloads under different Hadoop configurations.     

Development of human-machine interface for teleoperation of a mobile manipulator

Human-robot control interfaces have received increased attention during the past decades for conveniently introducing robot into human daily life. In this paper, a novel Human-machine Interface (HMI) is developed, which contains two components. One is based on the surface electromyography (sEMG) signal, which is from the human upper limb, and the other is based on the Microsoft Kinect sensor. The proposed interface allows the user to control in real time a mobile humanoid robot arm in 3-D space, through upper limb motion estimation by sEMG recordings and Microsoft Kinect sensor. The effectiveness of the method is verified by experiments, including random arm motions in the 3-D space with variable hand speed profiles.     

珠江水源水厂臭氧-生物活性炭工艺对有机微污染物的去除效果

近年来,我国经济发展势头强劲的珠江流域的水质不断受到污染,珠海市给水厂的水源也受到污染.建议通过臭氧生物活性炭深度处理工艺进一步提高污染物的去除率.研究采用小试试验对臭氧生物活性炭深度处理工艺进行研究.重点考察了臭氧质量浓度为1.0 mg/L、活性炭柱空床时间为15 min和臭氧质量浓度为1.5 mg/L、活性炭空床时间为30 min这两个工况下,2-甲基异莰醇、土臭素、TOC、UV254、浑浊度的去除效果,以及对消毒副产物前体物的控制效果,并通过分子量分布和三维荧光对水中的溶解性有机物进行分析,发现臭氧-生物活性炭工艺可以很好地去除2-甲基异莰醇和土臭素.臭氧-生物活性炭工艺可以有效地去除水中的溶解性有机物,对三卤甲烷和含氮类消毒副产物的前体物也有一定的去除作用,但是对于HAAs卤乙酸类的DBPs消毒副产物前体物的去除效果不佳.同时,文中也给出了臭氧生物活性炭深度处理工艺运行工况的建议.     

考虑多元可控负荷协调的配网鲁棒优化经济调度模型

为有效应对大规模分布式可再生能源和可控负荷接入配网后在经济优化调度方面所带来的挑战,本文建立考虑多元可控负荷协调的配网鲁棒优化经济调度模型.首先考虑电池储能系统、电动汽车及可参与需求侧管理的电负荷的能量转移特性,建立多元可控负荷可调模型;进而考虑配网中多元可控负荷的调峰能力及动态约束以运行成本最低建立配网鲁棒经济优化调度模型;最后,以蒙东某配网实际数据为例,在改进IEEE 14节点配电系统上进行调度仿真分析,验证本文所提出模型可充分利用多元可控负荷的调节能力,有效提升配网运行经济性.     

TEMPERED BAINITE EMBRITTLEMENT IN SOME STRUCTURAL STEELS

The variations of microstructures and mechanical properties of steels 15CrMnMoV,18Mn2CrMoB,18Cr2Ni4W,30CrMnSi,30CrMnSiNi2 and 40CrMnSiMoV,which weretempered at different temperatures after austempering and continuous cooling at given rates,have been investigated.Based on the experimental results,the behaviour and mechanism oftempered bainite embrittlement(TBE)have been discussed.Finally,the theoretical and prac-tical basis for selecting the optimum tempering temperature of steels with bainite structure af-ter heat treatment are proposed.     

EXPERIMENTAL TESTING OF DRAW—BEAD RESTRAINING FORCE IN SHEET METAL FORMING

Due to complexities of draw-bead restraining force calculated according to theory and depending on sheet metal forming properties experiment testing system, a simplified method to calculate draw-bead restraining force is put forward by experimental method in cup-shaped drawing process. The experimental results were compared with numerical results and proved agreement. It shows the method is effective.     

板料成形优化技术进展与质量工程研究

板料成形过程的优化研究对于改进模具设计、提高产品质量具有重要意义。综述了板料成形工艺优化的研究现状。考虑到在有约束的设计优化中,最优结果常位于约束边界附近,随机因素的波动易导致产品质量不稳定甚至失效,难以保持产品的可靠性和稳健性。为此,本文应用质量工程学中的6σ理念,提出了基于数值模拟的板料成形6σ稳健设计优化方法。     

隔焰辊道窑碳化硅板的研究

本文主要对隔焰辊道窑碳化硅板的配方选择、热震损伤、抗氧化性能和结构形状进行探讨.     

聚铝溶液pH值及盐基度的相关性研究

为聚铝溶液进行了ＰＨ值和盐基度的分析和估算,给出了聚铝溶液的极限ＰＨ值和极限盐基度与总溶解铝浓度的关系曲线,最终计算结果表明：在平衡条件下,聚铝溶液的ＰＨ值和盐基度具有相关性,即当基中一个参数发生变化时。另一个参数必然要发生相应的改变。