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Structure and bonding in quaternary Ag-Au-Pd-Pt clusters

JOURNAL OF ALLOYS AND COMPOUNDS 2016年第0期687卷 115-120页

作者： Wu, Xia Wei, Zheng Liu, Qiman Pang, Tao Wu, Genhua Anqing Normal Univ Sch Chem & Chem Engn Anqing 246011 Peoples R China Anqing Normal Univ Anhui Prov Lab Optoelect & Magnetism Funct Mat Anqing 246011 Peoples R China

Structural optimization of quaternary Ag-Au-Pd-Pt clusters up to 38 atoms is performed using adaptive immunea* optimization algorithm, and the Gupta many-body potential is adopted to model interatomic interaction. By fixing the atomic number of three types and varying the number of one type in quaternary clusters, geometrical effects by different types of noble metals are investigated. Results show that most configurations present the growth pattern based on the 19-atom double icosahedra, however, the structural transition model induced by increasing the number of the fourth noble atom is found to be different. Furthermore, the order parameter indicates that in quaternary clusters Ag and Au atoms mainly occupy the surface sites, Pd atoms tend to be in the middle shell, and the inner shell is located by Pt atoms. The study of the number of bonds indicates that Ag and Au atoms prefer scattering and forming a circle on the surface, respectively. (C) 2016 Elsevier B.V. All rights reserved.

关键词： Ag-Au-Pd-Pt clusters Stable structures optimization algorithm Growth pattern

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Energy systems in cost-optimized design of nearly zero-energy buildings

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AUTOMATION IN CONSTRUCTION 2016年第Oct.期70卷 109-127页

作者： Ferrara, Maria Fabrizio, Enrico Virgone, Joseph Filippi, Marco Politecn Torino DENERG Corso Duca Abruzzi 24 I-10129 Turin Italy Univ Turin DISAFA Largo Paolo Braccini 2 I-10095 Grugliasco TO Italy Univ Lyon 1 INSA Lyon CETHIL UMR5008 9 Rue Phys F-69621 Villeurbanne France

Cost optimization is one of the key elements of the EU regulatory framework concerning the energy performance of buildings. From this economic point of view, the optimum occurs when the global cost over the lifecycle of a building is minimized, and the cost-optimal energy performance level is that related to the minimum global cost. To determine this cost-optimal level by evaluating a great number of design alternatives, it is necessary to exploit automated optimization search procedures. The work presented here concerns the application of cost optimal methodology, as defined by European regulation, to a low-consumption single-family house in France. The calculation is performed through an iterative input-output process in a computing environment that combines TRNSYS (R), transient system simulation tool, with GenOpt (R), generic optimization program. The methodology that was adopted allowed around ten thousand building configurations to be simulated in a reasonable computational time. The paper focuses on how the energy system affects the technical and economic optimal design solutions of the building in two different French climate conditions. (C) 2016 Elsevier B.V. All rights reserved.

关键词： EPBD recast Cost-optimal analysis Dynamic building simulation Automated optimization optimization algorithm Particle swarm optimization France Cost function Single family house Design parameters

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Social and Location Analysis for Similarity Assessment: Multiparameter Social Search Based on Social Preferences and User Movements

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INTERNATIONAL JOURNAL OF INTERDISCIPLINARY TELECOMMUNICATIONS AND NETWORKING 2016年第4期8卷 22-33页

作者： Asmaryan, Albert Levanov, Alexey Borovik, Irina Bauman Moscow State Tech Univ Moscow Russia

This article introduces the method to assess similarity based on Facebook Graph API and users' movements. All movements of users are collected and analyzed. This paper presents a two-step multiparameter algorithm that generates recommendations based on users' social activity and movements. A flexible mechanism for the calculations of time that one spends on a variety of social activities to more accurately identify the relationships between users is presented. To reduce the load on the application the algorithms of data analysis and transfer optimization are proposed. The ultimate result of the study is to build a platform based on the "client-server" model and includes a mobile app on the iOS platform and server, which would be set up on the "LAMP" platform. The given result can be used and applied in various spheres of our lives to identify different relationships between people.

关键词： Assessment Model Location Multiparamter Analysis optimization algorithm Similarity algorithm Social Graph Social Networks

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An Improved Gbest-guided Artificial Bee Colony algorithm Based on Dynamic Regulatory Factor 8

An Improved Gbest-guided Artificial Bee Colony Algorithm Bas...

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8th International Conference on Advanced Computational Intelligence (ICACI)

作者： Huo, Jiuyuan Meng, Fanming Lanzhou Jiaotong Univ Sch Elect & Informat Engn Lanzhou Peoples R China

ISBN: (纸本)9781467377829

To address the problems of Gbest-guided artificial bee colony (GABC) algorithm that the low speed in the searching process and the solution is easy to fall into the local optimal, we presented an improved artificial algorithm with the dynamic regulatory factor (DRF-GABC). The dynamic regulatory factor was introduced into GABC algorithm to dynamically regulate the global optimization process and local optimal process of the algorithm. The improved algorithm was used for optimizing a set of numerical test functions and compared with the original ABC algorithm and the GABC algorithm. The experiments results show that the convergence performance of DRF-GABC algorithm is better than ABC algorithm and GABC algorithm, and it is suitable for solving optimization problems of complex function.

关键词： Artificial bee colony algorithm gbest-guided artificial bee colony algorithm dynamic regulatory factor optimization algorithm

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A Comparative Study on Optimal Transient Control of Aircraft Engines

A Comparative Study on Optimal Transient Control of Aircraft...

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Chinese Intelligent Systems Conference (CISC)

作者： Gao, Yang Wang, Jiqiang Wu, Xin Ye, Zhifeng Hu, Zhongzhi Dimirovski, Georgi Nanjing Univ Aeronaut & Astronaut Jiangsu Prov Key Lab Aerosp Power Syst Nanjing 210016 Jiangsu Peoples R China AVIC Shenyang Engine Design & Res Inst Shenyang 110015 Peoples R China Dogus Univ Istanbul TR-34722 Istanbul Turkey

ISBN: (纸本)9783662483862;9783662483848

Sequential quadratic programming has been widely used in the optimization of transient control of aircraft engine. On the other hand, the study of nonlinear optimization theory and method has been made great advance in recent years, of which active set method is one of the effective measures. In this article, the two algorithms are used to optimize the inputs based on one turbofan engine model. Results from the simulation comparisons of the two algorithms, advantages and disadvantages are given.

关键词： optimization algorithm SQP ASM Turbofan engine model

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Research on the route optimization for fresh air processing of air handling unit in spacecraft launching site

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APPLIED THERMAL ENGINEERING 2015年 86卷 292-300页

作者： Yang, Yongli Jiang, Pengcheng Cong, Hua Feng, Fuzhou Zhang, Hongxing Acad Armored Forces Engn Dept Mech Engn Beijing 100072 Peoples R China Taiyuan Satellite Launch Ctr Taiyuan 036304 Peoples R China

The existing control methods for Air handling units (AHUs) in spacecraft launching site (SLS) are comparatively dated, the air processing routes are usually arbitrarily determined in line with experience, which fails to cope with the coupling and function redundancy of air condition system and the diversity of outdoor environment, therefore resulting in tremendous energy waste. This paper proposes a new route optimization strategy for fresh air processing-Firstly analyzing the possibly processing routes for fresh air based on psychrometric chart, then proposing ana* optimization algorithm AFSA-GA to optimize the possibly processing routes, eventually obtaining the best route that requires the least energy consumption. By adopting the strategy proposed to optimize air processing route for High-Temperature and High-Humidity working conditions, it can be proved that the proposed strategy can decrease considerable amount of energy consumption, and the proposeda* optimization algorithm AFSA-GA has the advantages of faster convergence speed and avoiding premature. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： AHU Fresh air processing Psychrometric chart Route optimization optimization algorithm

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New optimization Strategy for Design of Active Twist Rotor

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AIAA JOURNAL 2015年第2期53卷 436-448页

作者： Kumar, Devesh Cesnik, Carlos E. S. Univ Michigan Dept Aerosp Engn Ann Arbor MI 48105 USA

This paper presents the development of a mixed-variable optimization framework for the aeroelastic analysis and design of active twist rotors. Proper tailoring of the blade properties can lead to the maximization of the active twist and the control authority for vibration reduction under operating conditions. Thus, using mathematical optimization, the cross-sectional layout is designed using continuous and discrete design variables for an active composite rotor blade to maximize the dynamic active twist while satisfying a series of constraints on blade cross-section parameters, stiffness, and strength. The optimization framework developed includes the Intelligent Cross-Section Generator as the cross-section and mesh generator, University of Michigan/Variational Asymptotic Beam Sectional analysis code for active cross-sectional analysis, and Rotorcraft Comprehensive Analysis Software for aeroelastic analysis of the active twist rotor blade. The optimization problem is solved using a surrogate-based approach in combination with the Efficient Globala* optimization algorithm. In this paper, the results with mixed design variables are obtained with three different techniques and are compared with the results obtained using continuous design variables.

关键词： Rotor Blades Aeroelastic Stability Twisted Rotor Blade Rotorcrafts Mathematical optimization optimization algorithm Finite Element Analysis Aerodynamic Characteristics Surrogate Model Genetic algorithm

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Combining Shaping and Flow Control for Aerodynamic optimization

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AIAA JOURNAL 2015年第4期53卷 888-901页

作者： Zhang, M. He, L. Univ Oxford Dept Engn Sci Parks Rd Oxford OX1 3PJ England Univ Oxford Dept Engn Sci Computat Aerothermal Engn Oxford OX1 3PJ England

Shape optimization and flow control have been extensively studied in the past to improve the performance of wings and blades. However, they are commonly applied as two separate disciplines, with their interactions being rarely studied. The present work aims to examine and identify the potential to explore the interactions between the two disciplines and is chiefly concerned about two related issues: 1) how much more performance improvement can be obtained by combining the shape optimization with the flow control optimization, and 2) the effects of the sequencing of the disciplines when the optimizations are combined. To address these issues, five optimization approaches have been studied, representing the shaping only, the flow control optimization only, and three different sequencings of the disciplines in the combined optimizations. All the optimization approaches are applied consistently by using the same optimization system developed in this research. The system uses the Kriging surrogate method as thea* optimization algorithm, and it incorporates a standard computational fluid dynamics solver for which the validity and numerical sensitivities have been assessed. The developed methodology is applied to two optimization cases of practical interest: a compressor blade and a circulation controlled airfoil. The results of both cases show that, when shaping and flow control optimizations are combined, the performance enhancement is considerably higher than when the two disciplines are applied separately. Furthermore, in the combined optimizations for the airfoil, it is observed that the concurrent optimization leads to the highest performance, whereas the sequential optimizations tend to be stuck at less optimal solutions.

关键词： Circulation Controlled Airfoil Shape optimization Control optimization Design of Compressor CFD optimization algorithm Flow Conditions Aerodynamic Efficiency Freestream Mach Number Reynolds Averaged Navier Stokes

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Automatic image annotation using feature selection based on improving quantum particle swarm optimization

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SIGNAL PROCESSING 2015年 109卷 172-181页

作者： Jin, Cong Jin, Shu-Wei Cent China Normal Univ Sch Comp Sci Wuhan 430079 Peoples R China Ecole Normale Super Dept Phys F-75231 Paris 5 France

Automatic image annotation (AIA) is a task of assigning one or more semantic concepts to a given image and a promising way to achieve more effective image retrieval and analysis. It is a typical classification problem. Due to the semantic gap between low-level visual features and high-level image semantic, the performances of many existing image annotation algorithms are not satisfactory. This paper presents a novel AIA scheme based on improved quantum particle swarm optimization (IQPSO) algorithm for visual features selection (VFS) and an ensemble stratagem based on boosting technique to improve performance of image annotation approach. To maintain the population diversity, the measure method of population diversity and improvement operation are proposed. To achieve better performance of ALA scheme, the measure of population diversity is as a control condition of VFS process. The classification result of an ensemble classifier is as the final annotation result rather than individual classifier. The experimental results confirm that the proposed AIA scheme is very effectiveness. When using proposed AIA scheme over three image datasets respectively, the annotation results are satisfactory. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Automatic image annotation Visual feature selection optimization algorithm Improvement operation Ensemble stratagem

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Surrogate-Based Shape optimization of Stall Margin and Efficiency of a Centrifugal Compressor

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JOURNAL OF PROPULSION AND POWER 2015年第6期31卷 1607-1620页

作者： Khalfallah, Smail Ghenaiet, Adel Benini, Ernesto Bedon, Gabriele Ecole Mil Polytech Appl Mech Lab Thermal Power Syst Algiers 16046 Algeria Univ Sci & Technol Houari Boumediene Fac Mech Engn Algiers 16111 Algeria Univ Padua Dept Ind Engn I-35131 Padua Italy

Centrifugal compressors are required to increase their operating range and efficiency, which are limited at low mass flow rates by the rotating stall and surge. This paper presents a surrogate-based multi-objective optimization of a centrifugal compressor to improve its efficiency and stall margin. Curvatures of the blade, the impeller shroud, and the diffuser hub are selected as optimization parameters since they influence highly both the efficiency and the stall limit. The implemented optimization procedure starts by the construction of a metamodel, which is the radial basis function that uses a database composed of a well-selected set of geometries and their corresponding computational fluid dynamics predicted objectives using the Ansys-CFX 12 code. The NSGA-IIa* optimization algorithm is used afterward to search the Pareto front based on radial basis function approximations. To improve the accuracy of the radial basis function and subsequently the Pareto front, a database refinement is sequentially achieved, using the leave-one-out-cross-validation uncertainty to select infill points. The present procedure is tested on the NASA low-speed centrifugal compressor, showing its ability to increase both the compressor operating range and efficiency. Furthermore, the flow pattern analysis confirms the suppression of separations that lead to instability in the optimized compressor at the stall point of the baseline design.

关键词： Centrifugal Compressor Shape optimization CFD Simulation Mass Flow Rate optimization algorithm Flow Patterns ANSYS Rotating Stall Aerodynamic Design Boundary Layer Thickness

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