基于混合双种群差分进化的电力系统经济负荷分配

针对电力系统经济负荷分配本质上的非线性约束优化问题,提出一种双种群混合差分进化算法.采用两个种群且以较小的计算量实现目标函数的寻优并保持解的可行性,同时引入单纯型法来提高算法的局部搜索能力.基于典型算例对该算法的进化行为进行测试,并通过仿真和比较验证了所提出算法的有效性.     

Gray编码对族群进化算法性能的改进

族群进化算法（EGEA）利用族群机制进行群体结构调控。在基于二进制编码的群体中,个体间编码的差异性被作为族群聚类的标准。由于自然二进制编码所存在的Hamming悬崖问题易影响族群聚类的准确性,从而降低EGEA的搜索效率,因此提出利用Gray编码连续个体间编码只有一位不同的特点来改进族群聚类的精度。针对典型多维函数的仿真实验表明,基于Gray编码的族群聚类过程可显著提高EGEA的收敛速度和解的精度。     

四腿机器人步态参数自动进化研究与实现

采用进化算法和基于自主视觉的适应度评估方法,实现了四腿机器人在RoboCup机器人足球比赛现场的行走步态在线自动进化．我们引入内推法作为交叉方法,利用PC基站进行进化算法计算和流程主控,并采用了一些学习时间缩减策略．实现了进化学习的连续性和可扩展性,使得学习过程可以在4060min内完成,这样就能在比赛现场对ERS-7四足机器人进行行走再学习,提高了行走控制的适应性．算法最终结果使ERS-7型四足机器人的行走速度从27cm/s提升到43cm/s．     

缺陷需求分析与管理模型

需求管理是软件过程改进的重要活动,需求缺陷管理是需求管理的重要组成部分,其目的在于检测、分析、解决和预防需求缺陷.从社会因素和技术因素两大方面分析了需求工程阶段缺陷产生的原因,对缺陷进行了分类.建立了需求(模型)缺陷列表、缺陷需求分析模型和基于需求缺陷管理的需求过程模型.指出需求缺陷列表所反映的需求分析过程的数量特征,能够为评估需求工程师能力、准确和全面地定义需求成熟度、研究需求演化波及效应、研究需求模型复杂度和需求缺陷分布规律提供必要数据和有益启示.     

An efficient multiobjective differential evolution algorithm for engineering design

Solving engineering design and resources optimization via multiobjective evolutionary algorithms (MOEAs) has attracted much attention in the last few years. In this paper, an efficient multiobjective differential evolution algorithm is presented for engineering design. Our proposed approach adopts the orthogonal design method with quantization technique to generate the initial archive and evolutionary population. An archive (or secondary population) is employed to keep the nondominated solutions found and it is updated by a new relaxed form of Pareto dominance, called Pareto-adaptive ϵ-dominance (paϵ-dominance), at each generation. In addition, in order to guarantee to be the best performance produced, we propose a new hybrid selection mechanism to allow the archive solutions to take part in the generating process. To handle the constraints, a new constraint-handling method is employed, which does not need any parameters to be tuned for constraint handling. The proposed approach is tested on seven benchmark constrained problems to illustrate the capabilities of the algorithm in handling mathematically complex problems. Furthermore, four well-studied engineering design optimization problems are solved to illustrate the efficiency and applicability of the algorithm for multiobjective design optimization. Compared with Nondominated Sorting Genetic Algorithm II, one of the best MOEAs available at present, the results demonstrate that our approach is found to be statistically competitive. Moreover, the proposed approach is very efficient and is capable of yielding a wide spread of solutions with good coverage and convergence to true Pareto-optimal fronts.     

传统工笔花鸟画中线条的发展与演变

线条是中国画的精髓和命脉,更是工笔花鸟画的灵魂。本文主要从线条作为中国画基本语言的层面,从正视传统的角度去研究工笔花鸟画线条。以古人工笔花鸟画典范之为切入点,梳理出工笔花鸟画线条的发展脉络。通过大量的名作赏析,加深人们对古人用线的认识和理解,从中受到启迪,获得灵感。从而更好的指导现代工笔花鸟画创作。     

Developable polynomial surface approximation to smooth surfaces for fabrication parameters of a large curved shell plate by Differential Evolution

This paper presents a simple and efficient method to approximate a developable surface to a compound design surface by a polynomial. It is required to predict a final shape of roll bending in the fabrication of a curved shell plate. The roll bending process usually makes the cylindrical or conical curvature from an initial flat plate. It means that the final shape is developable or the surface representation has zero Gaussian curvature. The fabrication shape is important in order to estimate process parameters of roller bending.An optimization problem is formulated to determine the polynomial surface which is in the closest proximity to the design surface or the given shell plate, which is subjected to developability. The results and the efficiency of this algorithm are verified and evaluated by applying it to some shell plates which are obtained from a real ship model. The predicted bending shape becomes fundamental information in determining more process parameters for the fabrication of a compound curved shell plate.     

Introduction to the 100th anniversary issue of the Psychological Review..

Discusses the evolution of the Psychological Review from its inception in 1894 as a general journal to its current status as a forum for theoretical discussion. A historical overview of Psychological Review is presented, and its 2 main subfields, cognition and perception, are outlined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amine Coordinated Electron-Rich Palladium Nanoparticles for Electrochemical Hydrogenation of Benzaldehyde

Electrocatalytic hydrogenation (ECH) is a burgeoning strategy for the sustainable utilization of hydrogen. However, how to effectively suppress the competitive hydrogen evolution reaction (HER) is a big challenge to ECH catalysis. In this study, amine (NH₂ R)-coordinated Pd nanoparticles loaded on carbon felt (Pd@CF) as a catalyst is successfully synthesized by a one-step solvothermal reduction method using oleylamine as the reducing agent. An exceptional ECH reactivity on benzaldehyde is achieved on the optimal Pd@CF catalyst in terms of a high conversion (89.7%) and selectivity toward benzyl alcohol (89.8%) at −0.4 V in 60 min. Notably, the Faradaic efficiency for producing benzyl alcohol is up to 90.2%, much higher than that catalyzed by Pd@CF-without N-group (41.1%) and thecommercial Pd/C (20.9%). The excellent ECH performance of Pd@CF can be attributed to the enriched electrons on Pd surface resulted from the introduction of NH₂ R groups, which strengthens both the adsorption of benzaldehyde and the adsorbed hydrogen (H_ads) on Pd, preventing the combination of H_ads to form H₂, that is, inhibiting the HER. This study gives a new insight into design principles of highly efficient electrocatalysts for the hydrogenation of unsaturated aldehydes molecules.     

Rational Design and Synthesis of Extremely Efficient Macroporous CoSe2–CNT Composite Microspheres for Hydrogen Evolution Reaction

Uniquely structured CoSe₂–carbon nanotube (CNT) composite microspheres with optimized morphology for the hydrogen‐evolution reaction (HER) are prepared by spray pyrolysis and subsequent selenization. The ultrafine CoSe₂ nanocrystals uniformly decorate the entire macroporous CNT backbone in CoSe₂–CNT composite microspheres. The macroporous CNT backbone strongly improves the electrocatalytic activity of CoSe₂ by improving the electrical conductivity and minimizing the growth of CoSe₂ nanocrystals during the synthesis process. In addition, the macroporous structure resulting from the CNT backbone improves the electrocatalytic activity of the CoSe₂–CNT microspheres by increasing the removal rate of generated H₂ and minimizing the polarization of the electrode during HER. The CoSe₂–CNT composite microspheres demonstrate excellent catalytic activity for HER in an acidic medium (10 mA cm^?2 at an overpotential of ≈174 mV). The bare CoSe₂ powders exhibit moderate HER activity, with an overpotential of 226 mV at 10 mA cm^?2. The Tafel slopes for the CoSe₂–CNT composite and bare CoSe₂ powders are 37.8 and 58.9 mV dec^?1, respectively. The CoSe₂–CNT composite microspheres have a slightly larger Tafel slope than that of commercial carbon‐supported platinum nanoparticles, which is 30.2 mV dec^–1.