Multi-objective service composition model based on cost-effective optimization

The widespread application of cloud computing results in the exuberant growth of services with the same functionality. Quality of service (QoS) is mostly applied to represent nonfunctional properties of services, and has become an important basis for service selection. The object of most existing optimization methods is to maximize the QoS, which restricts the diversity of users’ requirements. In this paper, instead of optimization for the single object, we take maximization of QoS and minimization of cost as two objects, and a novel multi-objective service composition model based on cost-effective optimization is designed according to the complicated QoS requirements of users. Furthermore, to solve this complex optimization problem, the Elite-guided Multi-objective Artificial Bee Colony (EMOABC) algorithm is proposed from the addition of fast nondominated sorting method, population selection strategy, elite-guided discrete solution generation strategy and multi-objective fitness calculation method into the original ABC algorithm. The experiments on two datasets demonstrate that EMOABC has an advantage both on the quality of solution and efficiency as compared to other algorithms. Therefore, the proposed method can be better applicable to the cloud services selection and composition.     

基于Stackelberg博弈的共享储能容量优化与商业模式研究

本文围绕我国能源结构转型面临的系能源大量投入使用所需规模化储能资源支撑的挑战,紧扣新时代战略发展方向,对新型储能商业模式进行研究。我国能源结构转型面临挑战——大量使用新型能源需要规模化储能资源的支撑,本文紧扣新时代战略发展方向,对新型储能商业模式进行了研究。研究了基于新能源互补的共享储能商业运营模式,实现了共享储能设备与新能源发电功率互济,并基于Stackelberg主从博弈方法对共享储能设备租赁进行定价,以实现了用户、储能商、电力公司多方利益的最大化。以用户侧储能为研究对象,建立了基于全寿命周期的储能容量优化配置模型,考虑具有短期用电需求的峰值型用户,提出了基于共享理念的储能合作社商业模式。最后通过算例及现场试验验证了所提出的共享储能商业模式的可行性。     

局部线性模型优化的灰度图像彩色化

提出一种有效的仅需要少量线条着色的灰度图像彩色化算法。该算法在Lab颜色空间实现,基于抠图拉普拉斯矩阵设计了一个局部线性优化模型,只需要少量的人工线条着色就能产生高质量的彩色化图像。该模型的彩色化效果总体上与现有方法相当,而在某些情况下,能降低在灰度图像彩色化过程中出现的色彩渗透问题。局部线性优化模型建立的代价函数最优解能通过求解稀疏线性方程组获得。在构建抠图拉普拉斯矩阵时,发现利用扩散距离来代替欧氏距离能对本文模型进一步改进。实验结果显示,用基于扩散距离的改进局部线性优化模型方法,和基于欧氏距离的局部线性优化模型算法相比较,在减少人工线条交互和彩色化效果方面都能有较好的改进。     

Efficient energy management of CO2 capture plant using control-based optimization approach under plant and market uncertainties

This paper employs a control-based optimization algorithm encompassing of an intelligence model predictive control (MPC) scheme and mixed integer non-linear programming (MINLP) for coal-fired power plant retrofitted with flexible solvent-based post combustion CO₂ capture (PCC) plant (integrated plant). The agility and robustness of the developed control algorithm (MPC) is demonstrated through the control response time and efficiency of energy requirement including the financial and operational benefits of the plant subjected to plant and market uncertainties. While, the MINLP is utilized to forecast plant operational modes by ensuring the operational fidelity of integrated plant. This involves utilization of historical (2011) and forecast (2020) market conditions (electricity tariff and carbon price) subject to maximum plant net operating revenue. The outcomes show that the future power plant will operate in mixed operation modes, for instance in unit turndown and load following modes, which contribute to a minimum capture energy penalty at 3.13 MJ_th/tonne CO₂. Moreover, under the same year (2020), MPC exhibits superior control performance by satisfactorily obtain 94% actual CO₂ capture from the ideal cumulative CO₂ capture. Additionally, the integrated plant is capable to resume approximately 96% actual revenue from the ideal net operating revenue projected by the control-based optimization algorithm. The algorithm demonstrates that the installation of control system package (MPC) into the flexible PCC plant associated with coal-power generator could contribute to efficient energy management subjects to unprecedented uncertainties.     

采用预测控制的地铁节能优化控制算法

本文针对地铁列车自动运行系统(automatic train operation,ATO)一般运行情况以及晚点延迟发车情况下的节能问题,基于预测控制算法设计了地铁节能优化控制算法.利用预测控制算法的在线滚动优化特性,通过设计含有能量消耗趋势优化项的控制目标函数,控制算法能够针对节能目标实现快速动态调整.通过调节目标函数中各优化项权重的相对大小,节能算法可以在满足列车时间与路程运行指标的同时,达到降低能耗的目的.在MATLAB平台上利用真实车辆模型对提出的节能优化控制算法进行了仿真,在列车不延迟与延迟的情况下,算法都很好地平衡了跟踪目标与节能目标,为地铁能耗动态优化控制提供了可行方案.     

New optimization method based on energy management in microgrids based on energy storage systems and combined heat and power

Microgrids can be assumed as a solution model for green energy sources, energy storage systems, and combined heat and power (CHP) systems. In this work, the cost and emission minimization based on a demand response (DR) program is considered an optimization problem. To solve the mentioned problem a new multiobjective optimization algorithm (improved particle swarm optimization) is proposed based on a fuzzy mechanism to select the optimal value. The microgrid system includes two CHP units, fuel cell and battery systems, and the heat buffer tank. In this problem, two different feasible operating regions have been assumed in CHPs. Accordingly, to decrease the operational cost, time-of-use, and real-time pricing DR programs have been simulated, and the impacts of the mentioned models are evaluated overload profiles. The effectiveness of proposed models has been applied on different cases studies by different scenarios. The proposed model solved the DR program, time of use-DR and real-time pricing-DR problems. The proposed model could reduce the cost about 10%.     

Design optimization of mid-frequency vibro-acoustic systems using a statistical modal energy distribution analysis model

Structural and Multidisciplinary Optimization - In the past decades, many researches have been done on the design optimization of low- and high-frequency vibro-acoustic systems. However, the work...     

基于QoS的D2D能效优化

为解决基站数十亿通信设备的通信能耗和D2D通信过程中复用频谱资源对蜂窝用户造成的干扰问题,建立一种优化模型系统,解决用户通信服务质量(quality of service,QoS)和系统能效的权衡问题。针对优化问题中遇到的NP难题,提出一种启发式资源分配算法1-search,降低用户搜索范围以及匹配用户的搜索时间;利用松弛的方法忽略次要干扰的影响,降低算法复杂度。仿真结果表明,1-search算法可以提高系统能效,具有较好的收敛性。     

基于威布尔分布的云计算能耗优化模型研究

针对云计算环境中复杂的虚拟机正常运行状态,提出将虚拟机运行看成由硬软件串联的可修复系统,用威布尔分布描述虚拟机硬软件正常运行的方法来建模缓解云计算高能耗问题。运用半马尔科夫过程刻画虚拟机运行过程、Laplace-Stielties变换简化数值计算、Bayesian定理去除限制条件,构建处理器利用率与能耗、性能的关系模型。再结合可修复系统寿命分布理论,调整虚拟机正常运行的威布尔分布函数,得到不同形状参数下处理器运行能耗以及给定任务完成时间,最终分析形状参数、处理器利用率与能耗-性能隐含关系并给出有效降低处理器运行能耗的合理化建议。数值分析表明：增大形状参数比提高利用率更显著降低处理器运行能耗;优化虚拟机配置使得形状参数变大,可以明显降低处理器运行能耗,同时避免云系统性能过度损耗。     

Label relaxation using a linear mixture model

Abstract

A label relaxation method with a proportional estimation of mixed pixels (mixels) which is based on inversion problem solving techniques with a previously estimated proportion of neighbouring mixels is proposed. The method allows us to check the connectivity of separated road segments which arc observed frequently in the remote sensing satellite imagery. The experimental results with simulation data including observation noise show 73·5-98·8 per cent of improvement in terms of proportional estimation accuracy (RMS error), compared to the results from the previously proposed method with a generalized inverse matrix. Also the usefulness of the proposed label relaxation method with the proposed proportional estimation was confirmed for the investigation of the connectivity of the roads in the remote sensing satellite imagery.     

TRANSMax II: Designing a flexible model for transit route optimization

Covering path problems date from the pioneering work of Current et al. (1984, 1985). Two basic forms were defined in their work: the shortest covering path problem and the maximal covering shortest path problem. These two problems differ in that one requires complete coverage by the defined path and the other involves determining path alternatives which cover as much as possible while keeping the path length as short as possible. The latter of these two problems, the maximal covering shortest path problem, embodies the two major goals in transit planning: that is, finding efficient paths which serve as many people as possible. Often transit routes are restricted to major road segments, and when that occurs, routes do not compete with one another unless they overlap along a street segment or at an intersection. In addition, coverage distances can be quite small, barely extending to other streets. Given this type of situation, Curtin and Biba (2011) developed a model called TRANSMax (Transit Route Arc-Node Service Maximization), which maximizes node and arc service, where service coverage is defined for only those street and node segments that are part of a route. They based their model on a structure first proposed by Vajda (1961) in formulating and solving the traveling salesman problem. Because of this structure, we demonstrate that it is possible that a route generated by their original TRANSMax model may not be Pareto optimal with respect to both distance and access. In this paper, we develop a flexible TRANSMax model formulation that finds Pareto Optimal solutions when the original form does not. We also present computational experience in solving this new model on the same street network of Curtin and Biba involving Richardson, Texas. This application allows us to make comparisons between this work and the original work of Curtin and Biba. Overall, we show that this new model can identify new, improved routes over the existing TRANSMax model.     

基于移动agent的B2B系统模型的设计与实现

文章介绍了移动agent技术特点及B2B商务活动过程,提出了一个基于移动agent的B2B商务模式系统模型,分析了系统组成部件的功能及应用的实现。     

Edge detection and linear feature extraction using a 2-D randomfield model

The edge-detection problem is posed as one of detecting step discontinuities in the observed correlated image, using directional derivatives estimated with a random field model. Specifically, the method consists of representing the pixels in a local window by a 2-D causal autoregressive (AR) model, whose parameters are adaptively estimated using a recursive least-squares algorithm. The directional derivatives are functions of parameter estimates. An edge is detected if the second derivative in the direction of the estimated maximum gradient is negatively sloped and the first directional derivative and a local estimate of variance satisfy some conditions. Because the ordered edge detector may not detect edges of all orientations well, the image scanned in four different directions, and the union of the four edge images is taken as the final output. The performance of the edge detector is illustrated using synthetic and real images. Comparisons to other edge detectors are given. A linear feature extractor that operates on the edges produced by the AR model is presented     

Designing a family of reconfigurable vehicles using multilevel multidisciplinary design optimization

Continuous advancements in technology have resulted in customers expecting enhanced performance across multiple operating conditions. In this paper, the desire to meet a variety of objectives after the system has been deployed is accomplished through the design of reconfigurable systems. However, permitting a system to adapt increases both complexity and cost. If this increase is too large, only a subset of design variables can be made adaptable. A multilevel multidisciplinary design optimization (MDO) approach is presented to determine the core architecture for a family of three reconfigurable vehicles when accommodating a changing number of adaptable design variables. To illustrate this approach, a case study involving a three-driver racing team is introduced. A common architecture is determined for the three vehicle variants, resulting in lap-time performance increases of 2.08%, 3.27%, and 3.67% when compared to the static, optimized baseline vehicle. The results of this study demonstrate the effectiveness of combining reconfigurability with product platforming and MDO. This paper is based on AIAA paper AIAA-2007-1880 that was reviewed for, and presented at, the 48th AIAA/ASMR/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference.     

Enhancement of vibration based piezoelectric energy harvester using hybrid optimization techniques

Microsystem Technologies - MEMS unimorph piezoelectric vibration energy harvester is designed and optimized based on Hybrid Optimization techniques [genetic algorithm (GA), bat algorithm (BA), grey...     

Minimum energy control for general model of 2-D linear systems

A new definition of the straight line controllability for the general model of 2-D linear systems is presented. Necessary and sufficient conditions for the straight line controllability of the general model are established. The minimum energy control problem for the general model of 2-D systems with constant coefficients is formulated and solved.     

A model for China's energy requirements and CO2 emissions analysis

This paper introduces a model and corresponding software for modeling China's Energy Requirements and the CO₂ Emissions Analysis System (CErCmA). Based on the input–output approach, CErCmA was designed for scenario analysis of energy requirements and CO₂ emissions to support policymakers, planners and others strategically plan for energy demands and environmental protection in China. In the system, major drivers of energy consumption are identified as technology, population, economy and urbanization; scenarios are based on the major driving forces that represent various growth paths. The input–output approach is employed to compute energy requirements and CO₂ emissions under each scenario. The development of CErCmA is described in a case study: China's energy requirements and CO₂ emissions in 2010 and 2020 are computed based on the input–output table of 1997. The results show that China's energy needs and related CO₂ emissions will grow exponentially even with many energy efficiency improvements, and that it will be hard for China to maintain its advantage of low per capita emissions in the next 20 years. China's manufacturing and transportation sectors should be the two major sectors to implement energy efficiency improvements. Options for improving this model are also presented in this paper.     

认知网络能量感知及伽玛统计模型能量优化算法

为了提升分簇无线传感器网络的能量效率并均衡节点的能量负载,提出了一种认知网络能量感知及伽玛统计模型能量优化算法。首先,该算法提出基于认知无线电的信道能量感知模型,可以得到网络休眠模式和运作模式下网络的能量分布方程。接着,在多个中继网络场景中采用伽玛函数进行网络总能耗分析,并基于次级网络跳数与簇头总能耗关系提出能量优化策略,在均衡簇头能量负载的同时最小化网络总能耗量。实验仿真结果表明,在网络总能量消耗上,所提出的能量优化算法相比基于节能路由方案的认知无线电网络和基于多能量探测器的认知网络,节能效果分别提高了37.6%和12.2%,并且算法采用伽玛函数对网络能量分布的分析具有一定的准确性。     

基于线性模型跟随的风力发电功率解耦控制

本文首先对包括风力机、无刷双馈发电机的风力发电系统进行建模, 并通过同步坐标变换分解为两个解耦子系统. 在此基础上, 采用双环控制使系统跟随参考模型的特性. 由功率特性曲线可知, 某一风速对应特定的最大功率. 针对无刷双馈发电机的复杂结构, 在控制系统的内环采用自抗扰控制, 可以很好的实现功率解耦控制; 外环采用线性模型跟随控制, 使得发电机能够很好的跟随模型特性. 仿真结果表明, 双环控制器可以使系统的输出功率快速的跟踪给定的功率, 实现完全模型跟踪, 证明了控制算法的有效性.     

Topology optimization using a continuous-time high-cycle fatigue model

Structural and Multidisciplinary Optimization - We propose a topology optimization method that includes high-cycle fatigue as a constraint. The fatigue model is based on a continuous-time approach...