A mathematical model of the heliostat field and the PSO-GA algorithm are developed in Matlab to optimize a heliostat field and determine the highest potential daily energy collection (DEC). The heliostat field in Lhas...
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A mathematical model of the heliostat field and the PSO-GA algorithm are developed in Matlab to optimize a heliostat field and determine the highest potential daily energy collection (DEC). The heliostat field in Lhasa, China is analyzed as an example. The energy collected per unit cost (ECUC) is then calculated to evaluate the economic performance of the heliostat field. Furthermore, the effects of several important factors on the heliostat field are also explored. Results indicate that, after optimization, the DEC during the spring equinox, summer solstice, autumnal equinox, and winter solstice increase by approximately 1.1 x 10(5), 1.8 x 10(5), 1.2 x 10(5), and 0.9 x 10(5) MJ, respectively. Studies on the key parameters show that as the number of heliostats in the first row of the field (Nhel(1)) increases, the ECUC first increases to its maximum value and then decreases. Additionally, ECUC increases with tower height but decreases as the cost of the heliostat mirror collector increases. (C) 2017 Elsevier Ltd. All rights reserved.
Considering the fault tolerance mechanism in the route optimization of the mobile wireless sensor network (MWSN), we analyze the routing fault tolerance between nodes and establish an intelligent fault-tolerant routin...
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Considering the fault tolerance mechanism in the route optimization of the mobile wireless sensor network (MWSN), we analyze the routing fault tolerance between nodes and establish an intelligent fault-tolerant routing model for MWSN. We also propose a novel fault-tolerant routing algorithm for an MWSN based on an artificial bee colony (ABC) optimized particle swarm optimization algorithm (ABC-PSO), and this optimizes the ABC-PSO algorithm is applied to study the optimal construction strategy of an alternate route. The proposed using of the path coding, the ABC algorithmoptimization, the collaborative updation, and the evolution of the principal and subordinate swarms, as well as particle selection, provide faster overall convergence performance and more accurate solutions for the network optimization. Analytical proofs and simulation experiments show that the route fault-tolerant strategy proposed in this paper can create a reliable transmission environment and an efficient route recovery mechanism for the MWSN. Moreover, it can lower the energy consumption of the network and increase the network's lifetime and improve the robustness and the reliability of MWSN.
The hybridization between conventional combined cooling heating and power (CCHP) systems and solar systems has been considered as a good solution to the urgent energy and environment issues. This study develops the ma...
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The hybridization between conventional combined cooling heating and power (CCHP) systems and solar systems has been considered as a good solution to the urgent energy and environment issues. This study develops the mathematical model of a CCHP system hybridized with PV panels and solar thermal collectors. The particleswarmoptimization (PSO) algorithm is adopted to find the optimum values of design parameters. Based on the energy output characteristic of the solar hybrid CCHP system, five operation strategies of the conventional CCHP system are adjusted and applied for the solar hybrid CCHP system. The simulation work of the hybrid CCHP systems based upon a hotel building in Atlanta is carried out to find an appropriate design scheme. The results show that the hybrid CCHP system under the FEL-ECR mode is the best choice. Besides, its PESR, CO2ERR and ATCSR can reach 36.15%, 53.73% and 4.16%, respectively. Compared with a conventional CCHP system, the hybrid CCHP system achieves better energy-saving and CO2 reduction performance. However, the hybrid CCHP system consumes more annual total costs because of its high initial investment.
Pricing American basket option is one of the essential problems in quantitative finance. The complexity of this type of option has motivated many practitioners and researchers to develop simulation-based methods. In t...
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Pricing American basket option is one of the essential problems in quantitative finance. The complexity of this type of option has motivated many practitioners and researchers to develop simulation-based methods. In this paper, we develop an optimized radial basis function neural network (RBFNN), which is optimally tuned by the particle swarm optimization algorithm to enhance the efficiency and accuracy of approximate dynamic programming (ADP) for pricing the American basket option. Additionally, for the scenario generation, a simulation-based technique using a copula-GARCH method and Extreme Value Theory is performed to tackle the nonlinearity of dependencies between variables. The prices obtained through the proposed approach compared with those ones achieved from pure RBFNN and ADP in different situations. This is also illustrated that the obtained prices of American basket option can outperform the results obtained through the RBFNN and ADP approaches in terms of the predefined fitness measures.
In this paper, we present a novel wavefront sensing method for diffraction optical system based on phase diversity. Based on the physical-imaging mechanism of diffractive optical system, the wavefront characteristics ...
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In this paper, we present a novel wavefront sensing method for diffraction optical system based on phase diversity. Based on the physical-imaging mechanism of diffractive optical system, the wavefront characteristics of the diffraction optical system are characterized by using diffraction efficiency. On this basis, a novel modified phase diversity (PD) wavefront sensing method is established based on the blocking idea. After that, the global optimization method of corresponding method based on particle swarm optimization algorithm is proposed. Finally, some experiment results are achieved with the experiment on a membrane diffraction optical system. Experimental results indicate that the proposed algorithm performs well on both wavefront reconstruction and image restoration and is far superior to traditional methods in diffraction optical systems. The accuracy of our proposed PD method is at least two orders of magnitude higher than the traditional method. Taking the 0.01 degrees field of view for example, our modified PD method can achieve the accuracy of 2.5 x 10(-4) wavelength when the diffraction efficiency is higher than 0.6. This proposed method can be applied to improve the image quality of the diffraction optical system and further support the on-orbit application of ultra-large aperture membrane imaging technology.
To cope with the approaching POST-2020 scenario, the national CO2 emission in the building sector, which accounts for 25.5% of the total CO2 emissions, should be managed effectively and efficiently. To do this, it is ...
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To cope with the approaching POST-2020 scenario, the national CO2 emission in the building sector, which accounts for 25.5% of the total CO2 emissions, should be managed effectively and efficiently. To do this, it is essential to forecast the national CO2 emissions in the building sector by region. As the South Korean government does not currently do this by region, regional characteristics are rarely taken into consideration when managing the national CO2 emissions in the building sector. Towards this end, this study developed an optimized gene expression programming model for forecasting the national CO2 emissions in 2030 using the metaheuristic algorithms. Compared to the forecasting performance of the gene expression programming model, the forecasting performance of the optimized gene expression programming harmony search optimization model has improved by 7.11, 2.05, and 2.06% in terms of the mean absolute error, root mean square error, and mean absolute percentage error, respectively. Various national CO2 emissions scenarios in the building sector were established in order to better analyze the variation range of the national CO2 emissions in the building sector. Compared to the national CO2 emissions in 2016 (i.e., scenario 1: 41,337 ktCO(2);scenario 2: 45,373 ktCO(2);scenario 3: 46,024 ktCO(2)) in multi-family housing complexes, the national CO2 emissions in 2030 (i.e., scenario 1: 37,579 ktCO(2);scenario 2: 37,736 ktCO(2);scenario 3: 37,754 ktCO(2)) in multi-family housing complexes are forecasted to increase by 10.00-21.91%. The developed optimized gene expression programming harmony search optimization model will potentially be able to assist policymakers in central and local governments forecast the national CO2 emissions in 2030. Through this, national CO2 emission management that more closely reflects the characteristics at the regional or national level can be supported.
An order scheduling problem arises in numerous production scheduling environments. Makespan, mean flow time, and mean tardiness are the most commonly discussed and studied measurable criteria in the research community...
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An order scheduling problem arises in numerous production scheduling environments. Makespan, mean flow time, and mean tardiness are the most commonly discussed and studied measurable criteria in the research community. Although the order scheduling model with a single objective has been widely studied, it is at odds with real-life scheduling practices. In practice, a typical manager must optimize multiple objectives. A search of the literature revealed that no articles had addressed the issue of optimizing an order scheduling problem with multiple objectives. Therefore, an order scheduling model to minimize the linear sum of the total flowtime and the maximum tardiness is introduced in this study. Specifically, several dominance relations and a lower bound are derived to expedite the search for the optimal solution. Three modified heuristics are proposed for finding near-optimal solutions. A hybrid iterated greedy algorithm and a particleswarm colony algorithm are proposed to solve this problem. Finally, a computational experiment is conducted to evaluate the performances of all proposed algorithms.
We study a partner selection problem for virtual manufacturing enterprises facing an uncertain environment. We propose a new method of using the grey system theory to account for uncertainties in a project's start...
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We study a partner selection problem for virtual manufacturing enterprises facing an uncertain environment. We propose a new method of using the grey system theory to account for uncertainties in a project's start time, completion time, transportation time, as well as cost. We first develop the concepts of delivery time agreement index and cost agreement index, and then formulate a multi-objective partner selection problem that maximizes the minimum delivery time agreement index, the average delivery time agreement index and the cost agreement index. A chaotic particleswarmoptimization (CPSO) algorithm is developed. Extensive computational results show that the proposed CPSO method outperforms the standard PSO in providing quality solutions more reliably.
Wireless location network combines data communication,contextual data collection and *** purpose of this network is to determine the positions of agents based on measurements between nodes and *** order to improve the...
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Wireless location network combines data communication,contextual data collection and *** purpose of this network is to determine the positions of agents based on measurements between nodes and *** order to improve the positioning accuracy of wireless location network,the usual method is to increase the density of nodes,especially the density of anchor nodes,so as to optimize the topology of the ***,the wireless location network node power is limited,especially the wireless sensor *** is necessary to increase power consumption to meet the needs of a large number of ***,it is required that a certain level of power consumption should be set in the wireless location network,and even require further reduction in power consumption in daily *** the same time,we need to maintain a certain positioning accuracy,which requires the optimization of power allocation in the network,to make sure that power and positioning accuracy of the network can meet the needs of the actual *** this paper,an optimization of power allocation based on particleswarmoptimization in wireless location network is proposed to optimize the power *** square position error bound is introduced as the evaluation standard of the network positioning *** the power optimization,the positioning accuracy of the network is improved.
The Grey Wolf Optimizer (GWO) algorithm is a novel meta-heuristic, inspired from the social hunting behavior of grey wolves. This paper introduces the chaos theory into the GWO algorithm with the aim of accelerating i...
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The Grey Wolf Optimizer (GWO) algorithm is a novel meta-heuristic, inspired from the social hunting behavior of grey wolves. This paper introduces the chaos theory into the GWO algorithm with the aim of accelerating its global convergence speed. Firstly, detailed studies are carried out on thirteen standard constrained benchmark problems with ten different chaotic maps to find out the most efficient one. Then, the chaotic GWO is compared with the traditional GWO and some other popular meta-heuristics viz. Firefly algorithm, Flower Pollination algorithm and particle swarm optimization algorithm. The performance of the CGWO algorithm is also validated using five constrained engineering design problems. The results showed that with an appropriate chaotic map, CGWO can clearly outperform standard GWO, with very good performance in comparison with other algorithms and in application to constrained optimization problems. (C) 2017 Society for Computational Design and Engineering. Publishing Services by Elsevier.
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