检索结果-内蒙古大学图书馆

IEEE International Conference on Computational Intelligence and Computing Research

作者： Vaishali R Kulkarni Veena Desai Department of Computer Science Engineering KLS Gogte Institute of Technology Belagavi India Department of Electronics and Communication Engineering KLS Gogte Institute of Technology Belagavi India

ISBN: (纸本)9781509006137

Multidimensional optimization is critically important in engineering, economics and other disciplines. There are several deterministic approaches to optimization, each of which has its own pros and cons. Swarm intelligence-based optimization algorithms have been gained popularity for their effectiveness and resource efficiency. Two such popular algorithms, namely artificial bee colony (ABC) and particle swarm optimization (PSO) have been investigated in this paper. These algorithms have been implemented to minimize a few unimodal and multimodal benchmark functions. Results have been analyzed and the comparative analysis has been performed in terms of quality of solutions and computing time. Matlab simulation results show that the ABC algorithm delivers more accurate optimization than PSO does; but it suffers from delayed convergence. On the other hand, PSO is faster; but its accuracy is relatively inferior.

关键词： Swarm intelligence artificial bee colony particle swarm optimization benchmark functions Particle swarm optimization activity based costing parametric subharmonic oscillator bee colonies optimization algorithms

来源：评论

学校读者我要写书评

暂无评论

Density-Tapered Spiral Arrays for Ultrasound 3-D Imaging

引用

IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL 2015年第8期62卷 1580-1588页

作者： Ramalli, Alessandro Boni, Enrico Savoia, Alessandro Stuart Tortoli, Piero Univ Florence Dept Informat Engn I-50139 Florence Italy Univ Rome Dept Engn I-00146 Rome Italy

The current high interest in 3-D ultrasound imaging is pushing the development of 2-D probes with a challenging number of active elements. The most popular approach to limit this number is the sparse array technique, which designs the array layout by means of complex optimization algorithms. These algorithms are typically constrained by a few steering conditions, and, as such, cannot guarantee uniform side-lobe performance at all angles. The performance may be improved by the ungridded extensions of the sparse array technique, but this result is achieved at the expense of a further complication of the optimization process. In this paper, a method to design the layout of large circular arrays with a limited number of elements according to Fermat's spiral seeds and spatial density modulation is proposed and shown to be suitable for application to 3-D ultrasound imaging. This deterministic, aperiodic, and balanced positioning procedure attempts to guarantee uniform performance over a wide range of steering angles. The capabilities of the method are demonstrated by simulating and comparing the performance of spiral and dense arrays. A good trade-off for small vessel imaging is found, e.g., in the 60 lambda spiral array with 1.0 lambda elements and Blackman density tapering window. Here, the grating lobe level is -16 dB, the lateral resolution is lower than 6 lambda, the depth of field is 120 lambda and, the average contrast is 10.3 dB, while the sensitivity remains in a 5 dB range for a wide selection of steering angles. The simulation results may represent a reference guide to the design of spiral sparse array probes for different application fields.

关键词： Spiral Simulation results optimization Procedure Steering density modulation layouts Small vessel DEPTH OF FIELD optimization algorithms arrays Three dimensional imaging

来源：评论

学校读者我要写书评

暂无评论

Facial Expression Intensity Estimation Using Ordinal Information

Facial Expression Intensity Estimation Using Ordinal Informa...

引用

IEEE Conference on Computer Vision and Pattern Recognition

作者： Rui Zhao Quan Gan Shangfei Wang Qiang Ji Department of Electrical Computer & Systems Engineering Rensselaer Polytechnic Institute School of Computer Science and Technology University of Science and Technology of China

ISBN: (纸本)9781467388528

Previous studies on facial expression analysis have been focused on recognizing basic expression categories. There is limited amount of work on the continuous expression intensity estimation, which is important for detecting and tracking emotion change. Part of the reason is the lack of labeled data with annotated expression intensity since expression intensity annotation requires expertise and is time consuming. In this work, we treat the expression intensity estimation as a regression problem. By taking advantage of the natural onset-apex-offset evolution pattern of facial expression, the proposed method can handle different amounts of annotations to perform frame-level expression intensity estimation. In fully supervised case, all the frames are provided with intensity annotations. In weakly supervised case, only the annotations of selected key frames are used. While in unsupervised case, expression intensity can be estimated without any annotations. An efficient optimization algorithm based on Alternating Direction Method of Multipliers (ADMM) is developed for solving the optimization problem associated with parameter learning. We demonstrate the effectiveness of proposed method by comparing it against both fully supervised and unsupervised approaches on benchmark facial expression datasets.

关键词： ANNOTATIONS EXPRESSION ANALYSIS Facial Expression Parameter Learning optimization algorithms

来源：评论

学校读者我要写书评

暂无评论

Memory Architecture Design for Nano Satellites

Memory Architecture Design for Nano Satellites

引用

IEEE Aerospace Conference

作者： Nikhil Gupta Bhavya Shahi Manipal Institute of Technology Manipal Karnataka 576104 India

ISBN: (纸本)9781467376778

This paper describes the memory architecture to improve the data transfer and storage in a small satellite. The main *** during the design stage of the architecture is to find a good balance between power consumption, cost, reliability and data processing capability. These variables directly impact each other, and it is important to achieve a suitable balance. For this, a low power flash memory is selected in conjunction with a faster static random access memory to improve the performance of the on-board computer on the satellite. In-built buffers of flash are suitably used to improve system performance. An extensive study of timing requirements to store data in memory is done. A comparison of performance at different voltage levels above the required minimum is done to get a balance between the required speed of programming the memory and power consumption. A highly modular and optimized algorithm is proposed for data transfer and storage which can be easily incorporated into a real time operating system. A method to further save the power is proposed by switching the flash memory to the power saving mode when its usage is not required.

关键词： buffer flash memory memory architecture nanosatellites real time operating systems static random access memory Memory architecture nano satellites Static random access storage flash memories data transmission buffers optimization algorithms

来源：评论

学校读者我要写书评

暂无评论

Microstructure of vapor deposited coatings on curved substrates

引用

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A 2015年第5期33卷

作者： Rodgers, Theron M. Zhao, Hengbei Wadley, Haydn N. G. Univ Virginia Dept Mat Sci & Engn Charlottesville VA 22904 USA

Thermal barrier coating systems consisting of a metallic bond coat and ceramic over layer are widely used to extend the life of gas turbine engine components. They are applied using either high-vacuum physical vapor deposition techniques in which vapor atoms rarely experience scattering collisions during propagation to a substrate, or by gas jet assisted (low-vacuum) vapor deposition techniques that utilize scattering from streamlines to enable non-line-of-sight deposition. Both approaches require substrate motion to coat a substrate of complex shape. Here, direct simulation Monte Carlo and kinetic Monte Carlo simulation methods are combined to simulate the deposition of a nickel coating over the concave and convex surfaces of a model airfoil, and the simulation results are compared with those from experimental depositions. The simulation method successfully predicted variations in coating thickness, columnar growth angle, and porosity during both stationary and substrate rotated deposition. It was then used to investigate a wide range of vapor deposition conditions spanning high-vacuum physical vapor deposition to low-vacuum gas jet assisted vapor deposition. The average coating thickness was found to increase initially with gas pressure reaching a maximum at a chamber pressure of 8-10 Pa, but the best coating thickness uniformity was achieved under high vacuum deposition conditions. However, high vacuum conditions increased the variation in the coatings pore volume fraction over the surface of the airfoil. The simulation approach was combined with an optimization algorithm and used to investigate novel deposition concepts to tailor the local coating thickness. (C) 2015 American Vacuum Society.

关键词： analog approach high vacuum Nickel plating low vacuum coating film thickness CONCAVE gas pressure Physical vapor deposition Gas turbine engines Vacuum deposition Simulation results Monte Carlo technique Substrates optimization algorithms BOND COATS

来源：评论

学校读者我要写书评

暂无评论

Energy-Efficient Hybrid Precoding for Millimeter Wave Systems In MIMO Interference Channels

Energy-Efficient Hybrid Precoding for Millimeter Wave System...

引用

IEEE Vehicular Technology Conference

作者： Chunhua Ma Jianfeng Shi Nuo Huang Ming Chen National Mobile Communications Research Laboratory Southeast University

ISBN: (纸本)9781509016990

In this paper, we investigate energy-efficient hybrid precoding which consists of baseband precoding and radio frequency (RF) precoding for Millimeter Wave (mmWave) systems over multi-input multi-output (MIMO) interference channels. The considered optimization problem is intractable because both the object function and the constraint are non-convex. Instead of solving the multivariate optimization problem directly, we propose a near-optimal algorithm which includes two steps. First, the original problem is reformulated into an equivalent univariate optimization problem. Second, a near-optimal hybrid precoder is obtained via an orthogonal matching pursuit (OMP) based algorithm. Numerical results verify that the proposed hybrid precoding algorithm achieves a near-optimal EE performance. Moreover, the energy efficiency (EE) maximization algorithm outperforms the sum rate maximization algorithm in terms of the EE performance, especially at high transmit power.

关键词： Objective function prediction coding Interference channels Energy efficiency millimeter wave Transmitter power optimization algorithms multiple input multiple output systems HYBRID Hybrid electric vehicles algorithms

来源：评论

学校读者我要写书评

暂无评论

Efficiencies and Objectives in Short Term Hydro Scheduling

Efficiencies and Objectives in Short Term Hydro Scheduling

引用

IEEE Power and Energy Society General Meeting

作者： Egill Benedikt Hreinsson School of Engineering and Natural Sciences University of Iceland

ISBN: (纸本)9781509041695

In short term hydro scheduling and optimization in a pure hydro system, a viable objective function is to minimize the water drawdown from a long term reservoir, thereby utilizing the characteristics and shape of efficiency curves for individual units, waterways and stations. This paper addresses the representation of key concepts related to these efficiencies, as represented by the generation and production functions in hydroelectric stations. To illustrate different aspects, data have been collected and analyzed for actual stations in the Icelandic hydro dominated power system and graphical results are presented for key concepts. These key results of the paper include marginal and average cost or objective function curves and definitions. The underlying objective could be to minimize water usage for all stations, as part of different possible objectives in short term hydro system optimization. The results should be helpful when designing optimization algorithms and interpreting their outputs, and in casting a light on what are important aspects in solving such practical optimization problems.

关键词： STATIONS Water utilization short duration optimization algorithms power systems Hydroelectric Power Plants Objective function

来源：评论

学校读者我要写书评

暂无评论

Coevolutionary Latent Feature Processes for Continuous-Time User-Item Interactions 16

Coevolutionary Latent Feature Processes for Continuous-Time ...

引用

Annual Conference on Neural Information Processing Systems

作者： Yichen Wang Nan Du Rakshit Trivedi Le Song College of Computing Georgia Institute of Technology Google Research

ISBN: (纸本)9781510838819

Matching users to the right items at the right time is a fundamental task in recommendation systems. As users interact with different items over time, users' and items' feature may evolve and co-evolve over time. Traditional models based on static latent features or discretizing time into epochs can become ineffective for capturing the fine-grained temporal dynamics in the user-item interactions. We propose a coevolutionary latent feature process model that accurately captures the coevolving nature of users' and items' feature. To learn parameters, we design an efficient convex optimization algorithm with a novel low rank space sharing constraints. Extensive experiments on diverse real-world datasets demonstrate significant improvements in user behavior prediction compared to state-of-the-arts.

关键词： Consumers Recommender systems EPOCH space-sharing behavior prediction Arts optimization algorithms procedural model

来源：评论

学校读者我要写书评

暂无评论

Towards Optimal algorithms for Prediction with Expert Advice 16

Towards Optimal Algorithms for Prediction with Expert Advice

引用

Annual ACM-Society for Industrial and Applied Mathmatics Symposium on Discrete algorithms

作者： Nick Gravin Yuval Peres Balasubramanian Sivan Microsoft Research

ISBN: (纸本)9781510819672

We study the classical problem of prediction with expert advice in the adversarial setting with a geometric stopping time. In 1965, Cover gave the optimal algorithm for the case of 2 experts. In this paper, we design the optimal algorithm, adversary and regret for the case of 3 experts. Further, we show that the optimal algorithm for 2 and 3 experts is a probability matching algorithm (analogous to Thompson sampling) against a particular randomized adversary. Remarkably, our proof shows that the probability matching algorithm is not only optimal against this particular randomized adversary, but also minimax optimal. Our analysis develops upper and lower bounds simultaneously, analogous to the primal-dual method. Our analysis of the optimal adversary goes through delicate asymptotics of the random walk of a particle between multiple walls. We use the connection we develop to random walks to derive an improved algorithm and regret bound for the case of 4 experts, and, provide a general framework for designing the optimal algorithm and adversary for an arbitrary number of experts.

关键词： optimization algorithms Professional personnel Regret Random walk overall design

来源：评论

学校读者我要写书评

暂无评论

Inverse Analysis of Deep Excavation Using Differential Evolution Algorithm

引用

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS 2015年第2期39卷 115-134页

作者： Zhao, B. D. Zhang, L. L. Jeng, D. S. Wang, J. H. Chen, J. J. City Univ Hong Kong Dept Civil & Architectural Engn Hong Kong Hong Kong Peoples R China Shanghai Jiao Tong Univ Dept Civil Engn State Key Lab Ocean Engn Shanghai 200240 Peoples R China Griffith Univ Gold Coast Campus Griffith Sch Engn Brisbane Qld 4222 Australia

This paper presents the applications of the differential evolution (DE) algorithm in back analysis of soil parameters for deep excavation problems. A computer code, named Python-based DE, is developed and incorporated into the commercial finite element software ABAQUS, with a parallel computing technique to run an FE analysis for all trail vectors of one generation in DE in multiple cores of a cluster, which dramatically reduces the computational time. A synthetic case and a well-instrumented real case, that is, the Taipei National Enterprise Center (TNEC) project, are used to demonstrate the capability of the proposed back-analysis procedure. Results show that multiple soil parameters are well identified by back analysis using a DE optimization algorithm for highly nonlinear problems. For the synthetic excavation case, the back-analyzed parameters are basically identical to the input parameters that are used to generate synthetic response of wall deflection. For the TNEC case with a total of nine parameters to be back analyzed, the relative errors of wall deflection for the last three stages are 2.2, 1.1, and 1.0%, respectively. Robustness of the back-estimated parameters is further illustrated by a forward prediction. The wall deflection in the subsequent stages can be satisfactorily predicted using the back-analyzed soil parameters at early stages. Copyright (c) 2014 John Wiley & Sons, Ltd.

关键词： excavations inverse analysis differential evolution optimization algorithms deflection Cam-clay model

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：