An emerging time-varying distributed multi-energy management problem (MEMP) considering time-varying load and emission limitations for resisting time-varying external disturbances and communication time delays in the ...
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An emerging time-varying distributed multi-energy management problem (MEMP) considering time-varying load and emission limitations for resisting time-varying external disturbances and communication time delays in the multi-microgrid (MMG) system is investigated. Each microgrid (MG) contains some smaller microgrids (SMGs), which are connected by energy routers (ERs) of the system and can monitor energy in real-time with each other. In addition, a time-varying multi-energy management optimization model (MEMOM) is proposed in this paper in order to minimize the total cost of the MEMP which considers environmental cost, renewable energy cost and fuel cost. Furthermore, time-varying distributed neurodynamic optimization algorithms are proposed for solving the above MEMP based on consensus theory and sliding mode control technique. Compared with the optimization algorithms which consist of symbolic functions proposed in traditional energy management problems, algorithms consisting of hyperbolic tangent functions proposed in this paper can effectively reduce the oscillation of the algorithms and improve the stability of algorithms. Furthermore, the algorithm can converge the optimal trajectory of optimization problems with time-varying external disturbances and communication time delays. Meanwhile, the stability and convergence of the algorithms are proved theoretically by constructing appropriate Lyapunov functions. Finally, the performance evaluation re-sults of numerical simulations show that the proposed algorithms can efficiently handle energy trading under time-varying load and maintain excellent stability with time-varying external disturbances and communication time delays.(c) 2023 ISA. Published by Elsevier Ltd. All rights reserved.
Swarm intelligence is a research field that models the collective behavior in swarms of insects or animals. Recently, a kind of Drosophila (fruit fly) inspired optimization algorithm, called fruit fly optimization alg...
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Swarm intelligence is a research field that models the collective behavior in swarms of insects or animals. Recently, a kind of Drosophila (fruit fly) inspired optimization algorithm, called fruit fly optimization algorithm (FOA), has been developed. This paper presents a variation on original FOA technique, named multi-swarm fruit fly optimization algorithm (MFOA), employing multi-swarm behavior to significantly improve the performance. In the MFOA approach, several sub-swarms moving independently in the search space with the aim of simultaneously exploring global optimal at the same time, and local behavior between sub-swarms are also considered. In addition, several other improvements for original FOA technique is also considered, such as: shrunk exploring radius using osphresis, and a new distance function. Application of the proposed MFOA approach on several benchmark functions and parameter identification of synchronous generator shows an effective improvement in its performance over original FOA technique. (C) 2014 Elsevier Inc. All rights reserved.
Market analyzers use different parameters as features in the market data to analyze the market trends. The feature's values act as a signal to market fluctuations. Many studies have examined these features to pred...
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Market analyzers use different parameters as features in the market data to analyze the market trends. The feature's values act as a signal to market fluctuations. Many studies have examined these features to predict market movement more effectively. However, the method to minimize the uncertainties associated with the features is not available in the literature. This exploratory study introduces the uncertainty optimization based feature selection method for stock marketing. We introduce a notion of certainty region of the feature as the set of feature values, which signify particular happening with certainty. We use rough set theory to find the feature's certainty region and uncertainty region and measure each feature's significance. The feature whose certainty region is the maximum is the most significant in the feature space. Hence we group the features by minimizing the uncertainty region of the most informative features to get feature subsets for feature selection. We propose an algorithm based on uncertainty optimization to find subsets of the feature set for effectiveness and performance enhancement in the feature selection. We obtain the decision rules with comprehensive coverage and excellent support using the selected features. The accuracy of classification using the chosen parameters is up to 85.91%, which is higher than 79.54% of the complete feature set. The study provides an uncertainty optimization model for more efficient market movement prediction.
As technologies continue to be developed to enable the private and commercial use of super and hypersonic aerospace systems, one of the many issues that must be addressed is the optimization of supersonic flow paths t...
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ISBN:
(数字)9781624106095
ISBN:
(纸本)9781624106095
As technologies continue to be developed to enable the private and commercial use of super and hypersonic aerospace systems, one of the many issues that must be addressed is the optimization of supersonic flow paths that involve both area change and heat addition, such as those present in scramjets. The ever-expanding capability of computers to solve complex optimization problems can help decrease the development cost of propulsion systems by removing guesswork involved in early experimental design. This paper works to develop a novel approach for numerically computing flow properties along an arbitrary flow path with both area change and heat addition. Using the numerical approach as a performance metric, this paper will go on to implement a genetic algorithm that finds the optimal geometry and fuel addition profiles to maximize the thrust a propulsion device can generate. This tool is designed both for use as a computational rapid prototyping to inform early design choices for supersonic propulsion systems as well as a baseline metric for the performance of later iterations of design refinement, such as computational fluid dynamics models and experimental results. The presented approach is unique in the minimalistic nature of the code implementation and the lack of previous knowledge required of the solution space.
We have proposed a novel control method that in which proportional-integral (PI) control and optimized control are combined to stabilize permanent-magnet synchronous motors (PMSMs) for electric vehicles (EVs). The inv...
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ISBN:
(纸本)9781728163444
We have proposed a novel control method that in which proportional-integral (PI) control and optimized control are combined to stabilize permanent-magnet synchronous motors (PMSMs) for electric vehicles (EVs). The inverter current, which maximizes the torque and minimizes power, is calculated by the optimized control method. The simulations and experiments were performed to verify the effectiveness of the control. The experiment was carried out using the RX62T micromputer, which is an IC for automobile control, and a digital control system (PE-Expert4). Compared with the conventional speed PI control, the optimized control suppresses the decrease in motor speed and shortens the recovery time. As a result, we confirmed that the responsiveness was improved by 3 3 %. From this result, the optimized control method. which simultaneously controls and monitor speed, was shown to be effective in solving the problems of the conventional method.
Variable-angle-tow (VAT) composite laminates can eventually improve the mechanical performance of lightweight structures by taking advantage of a larger design space compared to straight-fiber counterparts. Here, we p...
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Variable-angle-tow (VAT) composite laminates can eventually improve the mechanical performance of lightweight structures by taking advantage of a larger design space compared to straight-fiber counterparts. Here, we provide a scalable low- to high-fidelity methodology to retrieve the tow angles that maximize the buckling load and the fundamental frequency of VAT plates. A genetic algorithm is used to solve the optimization problem in which the objective function is mimicked using a surrogate model. Both unconstrained and manufactured-constrained problems are solved. The surrogates are built with outcomes from numerical models generated by means of the Carrera unified formulation, which enables to obtain straightforwardly different degrees of accuracy by selecting the order of the structural theory employed. The results show both the validity and flexibility of the proposed design approach. It is shown that, although the optimal design fiber angle orientations are consistently similar, discrepancies in the prediction of the buckling load or fundamental frequency can be found between high-fidelity layerwise and low-to-refined equivalent-single-layer models, of which classical laminated plate or first-shear deformation theories are degenerate examples.
We present a novel approach to solving a specific type of quasilinear boundary value problem with p-Laplacian that can be considered an alternative to the classic approach based on the mountain pass theorem. We introd...
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We present a novel approach to solving a specific type of quasilinear boundary value problem with p-Laplacian that can be considered an alternative to the classic approach based on the mountain pass theorem. We introduce a new way of proving the existence of nontrivial weak solutions. We show that the nontrivial solutions of the problem are related to critical points of a certain functional different from the energy functional, and some solutions correspond to its minimum. This idea is new even for p = 2. We present an algorithm based on the introduced theory and apply it to the given problem. The algorithm is illustrated by numerical experiments and compared with the classic approach.
The paper uses parallel computation of grid and data grid as theoretical basis. The isomerism of each node and difference of communication rate under grid environment, and massive data query makes query operations of ...
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ISBN:
(纸本)9781479932795
The paper uses parallel computation of grid and data grid as theoretical basis. The isomerism of each node and difference of communication rate under grid environment, and massive data query makes query operations of database difficult. For the new structural characteristic, the paper proposes a parallel JOIN algorithm based on massive data, it fully uses parallelism and reduces transmission volume to shorten response time. The paper includes implementation and optimization of JOIN algorithm, fault-tolerant mechanism, RDMM, partition and transmission of massive data.
With the development of globalization and artificial intelligence,as well as the outbreak of COVID-19,unmanned vehicles have played an important role in cargo *** order to better analyze the research directions of unm...
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With the development of globalization and artificial intelligence,as well as the outbreak of COVID-19,unmanned vehicles have played an important role in cargo *** order to better analyze the research directions of unmanned vehicle distribution,this paper summarizes the models and algorithms of unmanned vehicle distribution *** research results show that most of the studies have established the goal of optimizing the total costs or travel *** researchers have begun to study multi-objective optimization problems,but there are certain limitations,so some studies convert these problems into single-objective optimization for solving,such as converting time and energy consumption into cost,waiting time into distance,and time delay into penalty *** the development of unmanned vehicle distribution technology,in future research,a multi-objective model with the lowest cost,the shortest distance and the best security should be established and *** studies have proposed heuristic algorithms for solving the unmanned vehicle distribution problem,and improved optimization solutions have been *** order to ensure the diversity of solution methods,and give consideration to solution time and solution quality,hybrid methods with other algorithms will be a future research direction,for example,the combination of heuristic algorithm and exact *** the gradual deepening of research,integrated distribution of multiple types of unmanned equipment will become the focus of future research.
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