一种磁控管用扼流线圈仿真设计

采用电路仿真软件仿真滤波组件S参数曲线,观察曲线随器件参数的变化;介绍利用三维全波电磁仿真软件HFSS简化设计流程的方法,并与测试结果对比。结果表明:利用3D仿真软件在满足器件设计精度的同时可以简化线圈的设计流程。     

Influencer-defaulter mutation-based optimization algorithms for predicting electricity prices

Efficient electricity price forecasting plays a significant role in our society. In this paper, a novel influencer-defaulter mutation (IDM) mutation operator has been proposed. The IDM operator has been combined with six well-known optimization algorithms to create mutated optimization algorithms whose performance has been tested on twenty-four standard benchmark functions. Further, the artificial neural network is integrated with mutated optimization algorithms to solve the electricity price prediction problem. The policymakers can identify appropriate variables based on the predicted prices to help future market planning. The statistical results prove the efficacy of the IDM operator on the recent optimization algorithms.     

A constrained portfolio selection model at considering risk-adjusted measure by using hybrid meta-heuristic algorithms

Portfolio selection is a key issue in the business world and financial fields. This article presents a new decision making method of portfolio optimization (PO) issues in different risk measures by using new evolutionary computing method and cardinality constrains which is mentioned as hybrid meta-heuristic algorithms. Based on mean–variance (MV) Method by Markowitz we collected three risk levels; mean absolute deviation (MAD), semi variance (SV) and variance with skewness (VWS). The developed algorithms are Electromagnetism-like algorithm (EM), particle swarm optimization (PSO), genetic algorithm (GA), genetic network programming (GNP) and simulated annealing (SA). Also a diversification mechanism strategy is implemented and hybridized with the developed algorithms to increase the diversity and overcome local optimality. The sustainability of this proposed model is verified by 50 factories on the Iranian stock exchange. Finally, experimental results of proposed algorithms with cardinality constraint are compared with each other by four effective metrics in which the algorithms performance for achieving the optimal solution discussed. In addition, we have done the analysis of variance technique to confirm the validity and accurately analyze of the results which the success of this method was proved.     

Diagnosis of the surface morphology of laser-ablated materials using the weighted- DCT approach in laser speckle interferometry for application to plasma facing materials

To implement on-line, real-time monitoring for the surface morphology of Plasma-Facing Materials (PFMs) in tokamak, we developed a Laser Speckle Interferometry measurement approach. A laser ablation method was used to simulate the erosion process during Plasma-Wall Interactions in a tokamak. In the present investigation, we evaluated the results of laser ablation morphology changes on the surface of Mo material reconstructed by four different approaches (Flood-fill, Quality-guided, Discrete Cosine Transform (DCT) and Weighted-DCT). The morphology results measured by the weighted-DCT approach are very close to the measurement results from confocal microscopy with an average error rate within 7%. It is verified that the weighted-DCT algorithm has high accuracy and can efficiently reduce the influence of noise pollution coming from laser ablation, which is used as a proxy for erosion from plasma wall interaction. Additionally, the CPU computer time has been shortened. This is of great significance for the real-time monitoring of PFMs’ morphology in the Experimental Advanced Superconducting Tokamak (EAST) in the future.     

国内农用拖拉机自动转向系统研究现状

作为精准农业的重要组成部分,农用拖拉机自动转向系统的研究也越来越多。通过对相关文献进行梳理和分析,分别从自动转向系统的两个组成部分(自动转向执行机构和自动转向控制系统)阐述国内农用拖拉机自动转向系统的研究成果,为设计合理的自动转向执行机构和稳定准确的自动转向控制系统提供建议和参考。     

Decreasing Filter Cake Resistance by Using Packing Structures

Packed beds used in absorption columns are evaluated to determine whether they can also be beneficial for cake‐forming filtrations. To assess this, model systems are characterized and separated by using a dead‐end filter cell. Filtrations are conducted with different packings; the filtrate amount over time and resulting turbidity are evaluated. Packings increase the filter cake resistance and the separation time of the cakes formed with approximately incompressible solids. However, they exhibit a positive effect on the filtration of a more complex, compressible substance; the process is not only accelerated, but also the quality of the obtained filtrate is not compromised. These results demonstrate potential in the use of packed beds for the filtration of complex biogenic suspensions.     

Interface reactions between rutile coatings and molten aluminium or AlSi7Mg0.6 alloy

Rutile coatings deposited on corundum substrates are considered as promising functional elements improving the efficiency of the filtration of oxide inclusions out of aluminium melts. This contribution describes the reactions between rutile and two kinds of the aluminium melts and discusses the consequences of these reactions for the filtration process. It was found that the contact of rutile coatings with molten aluminium leads to the formation of a corundum layer at the solid/liquid interface. The exposure of the rutile coatings to molten AlSi7Mg0.6 alloy produces an interface layer of MgTiO₃. The interface layers possess defined orientation relationship to rutile which is characteristic for locally heteroepitaxial growth. The density functional theory calculations revealed that the TiO₂/α-Al₂O₃ and TiO₂/MgTiO₃ interfaces with the orientation relationships observed experimentally have low interface energies. The mechanisms of the interface layer formation and the impact of these layers on the degradation of the rutile coatings are discussed.     

Cost-based holistic twig joins

An evaluation of XML queries such as XQuery or XPath expressions represents a challenging task due to its complexity. Many algorithms have been introduced to cope with this problem. Some of them, called binary joins, evaluate separated parts of a query and subsequently merge intermediate results, while the others, called holistic twig joins, evaluate a query as a whole. Moreover, these algorithms also differ in what index data structure they use to handle XML data. There exist cost-based approaches utilizing binary joins and various index data structures; however, they share a limitation. The limitation is that they cannot perform a join between query nodes not having a direct XPath relationship. Such a join can be advantageous especially if their joint selectivity is high. Since holistic joins work with all query nodes they overcome this limitation. In this article, we introduce such a holistic twig join called CostTwigJoin. To the best of our knowledge, CostTwigJoin is the first holistic join capable of combining various index data structures during an evaluation of an XML query. Usage of the holistic join has yet another advantage for cost-based approaches: an optimizer does not have to resolve the order of binary joins; therefore, the search space is reduced. In this article, we perform thorough experiments on hundreds of queries to evaluate our approach and demonstrate its advantages.     

Quantum computation based bundling optimization for combinatorial auction in freight service procurements

Combinatorial auction is a useful trade manner for transportation service procurements in e-marketplaces. To enhance the competition of combinatorial auction, a novel auction mechanism of two-round bidding with bundling optimization is proposed. As the recommended the auction mechanism, the shipper/auctioneer integrates the objects into several bundles based on the bidding results of first round auction. Then, carriers/bidders bid for the object bundles in second round. The bundling optimization is described as a multi-objective model with two criteria on price complementation and combination consistency. A Quantum Evolutionary Algorithm (QEA) with β-based rotation gate and the encoding scheme based on non-zero elements in complementary coefficient matrix is developed for the model solution. Comparing with a Contrast Genetic Algorithm, QEA can achieve better computational performances for small and middle size problems.