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991.
Nasser Yousefi 《Complexity》2016,21(6):299-308
This article presents the design and application of an efficient hybrid heuristic search method to solve the practical economic dispatch problem considering many nonlinear characteristics of power generators, and their operational constraints, such as transmission losses, valve‐point effects, multi‐fuel options, prohibited operating zones, ramp rate limits and spinning reserve. These practical operation constraints which can usually be found at the same time in realistic power system operations make the economic load dispatch (ELD) problem a nonsmooth optimization problem having complex and nonconvex features with heavy equality and inequality constraints. A particle swarm optimization with time varying acceleration coefficients is proposed to determine optimal ELD problem in this paper. The proposed methodology easily takes care of solving nonconvex ELD problems along with different constraints like transmission losses, dynamic operation constraints, and prohibited operating zones. The proposed approach has been implemented on the 3‐machines 6‐bus, IEEE 5‐machines 14‐bus, IEEE 6‐machines 30‐bus systems and 13 thermal units power system. The proposed technique is compared with solve the ELD problem with hybrid approach by using the valve‐point effect. The comparison results prove the capability of the proposed method give significant improvements in the generation cost for the ELD problem. © 2015 Wiley Periodicals, Inc. Complexity 21: 299–308, 2016  相似文献   
992.
This article focus on optimal economic load dispatch based on an intelligent method of shark smell optimization (SSO). In this problem, the risk constrains has been considered which has root in uncertainity and unpredictable behavior of wind power. Regarding to increasing of this clean energy in power systems and un‐dispatchable behavior of wind power, its conditional value at risk index considered in this article which consists of loss from load and "spilling" wind energy connected with unpredictable imbalances among generation and load. This problem has been considered as an optimization problem based on SSO that evaluate the balance between cost and risk. This algorithm is based on distinct shark smell abilities for localizing the prey. In sharks' movement, the concentration of the odor is an important factor to guide the shark to the prey. In other words, the shark moves in the way with higher odor concentration. This characteristic is used in the proposed SSO algorithm to find the solution of an optimization problem. Effectiveness of the proposed method has been applied over 30‐bus power system in comparison with other techniques. © 2016 Wiley Periodicals, Inc. Complexity 21: 494–506, 2016  相似文献   
993.
Smart transportation technologies require real‐time traffic prediction to be both fast and scalable to full urban networks. We discuss a method that is able to meet this challenge while accounting for nonlinear traffic dynamics and space‐time dependencies of traffic variables. Nonlinearity is taken into account by a union of non‐overlapping linear regimes characterized by a sequence of temporal thresholds. In each regime, for each measurement location, a penalized estimation scheme, namely the adaptive absolute shrinkage and selection operator (LASSO), is implemented to perform model selection and coefficient estimation simultaneously. Both the robust to outliers least absolute deviation estimates and conventional LASSO estimates are considered. The methodology is illustrated on 5‐minute average speed data from three highway networks. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
994.
《Optimization》2012,61(3):377-394
The existence of short-term monetary equilibrium in a frictionless economy with suboptimal agents is proved for any (reasonable) given interest rate. Money is distinguished from monetary assets. Separability ideas (as defined in decision theory) are applied. Two financial markets are in operation: for bank contracts (deposits and credits) and for shares.  相似文献   
995.
As an active participant of a competitive energy market, the generator (the energy supplier) challenges new management decisions being exposed to the financial risk environment. There is a strong need for the decision support models and tools for energy market participants. This paper shows that the stochastic short-term planning model can be effectively used as a key analytical tool within the decision support process for relatively small energy suppliers (price-takers). A self-scheduling method for the thermal units on the energy market is addressed. A schedule acquired for given preferences can be used as a desired pattern for bidding process. The uncertainty of the market prices is modeled by a set of possible scenarios with assigned probabilities. Several risk criteria are introduced leading to a multiple criteria optimization problem. The risk criteria are well appealing and easily computable (by means of linear programming) but they meet the formal risk aversion standards. The aspiration/reservation based interactive analysis applied to the multiple criteria problem allows us to find an efficient solution (generation scheme) well adjusted to the generator preferences (risk attitude).  相似文献   
996.
财务危机预警中财务比率的选择研究   总被引:3,自引:0,他引:3  
本文采用定性与定量相结合的方法对财务危机预警中财务比率的选择进行了研究 .首先根据初选原则对财务比率进行了初步选择 ,然后提出了一种基于神经网络的变量选择方法 ,对初选的财务比率进行定量筛选并进行了实证研究 ,结果表明 ,这是一种科学、通用的变量选择方法  相似文献   
997.
如何对地区公民旅游消费总额进行预测 ,是经济工作者及相关行业关注的问题 .本文用模糊系统分析的方法 ,建立一个地区的 L.R— L.P模型 ,利用模型的参数进行预测 ,提供一种辅助方法 .  相似文献   
998.
In deregulated electrical systems, production schedule for power plants is the result of an auction process. In the Spanish case, this schedule includes two main concepts: energy production (to be actually produced) and secondary reserve (to maintain available). The generation company faces the problem of converting energy schedule into a power schedule, respecting the reserve schedule as well as technical constraints, and trying to accomplish different goals: to minimise the production costs, to obtain smooth shapes for the power schedules and to optimise eventual compensation in schedules. A weighted goal mixed integer programming model with a real-size application to deal with this problem is presented.  相似文献   
999.
吴艳蕾 《大学数学》2007,23(1):133-135
在极限理论及其前人对非负权重最优组合算法研究的基础之上,提出了一种求解非负权重近似最优解的简明算法,并进行了实例分析,结果令人满意,验证了该方法的实用性和有效性.  相似文献   
1000.
我国专利申请量的支持向量机预测模型研究   总被引:3,自引:0,他引:3  
运用支持向量机(support vector machine,SVM)和浮点遗传算法相结合的方法对我国专利申请量进行预测。数据仿真显示支持向量机预测方法比人工神经网络和逻辑回归方法有更高的预测精度,结果显示运用浮点遗传算法参数选取的支持向量机方法对我国专利申请量进行预测是可行和有效的。  相似文献   
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