The performance of digital image correlation (DIC) method heavily depends on the quality of the speckle pattern. Extensive studies have been conducted to evaluate the speckle pattern, in order to reduce the errors of ...
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The performance of digital image correlation (DIC) method heavily depends on the quality of the speckle pattern. Extensive studies have been conducted to evaluate the speckle pattern, in order to reduce the errors of DIC. It is generally understood that the sum of square of subset intensity gradients (SSSIG) is the most relevant metric to the accuracy of the DIC;and the higher SSSIG indicates the better quality of the speckle pattern. However, there are few works on the optimization of the speckle pattern. In this work, we propose an integer programming method (IPM) to obtain the subset having the highest SSSIG. The speckle pattern derived from the proposed IPM has a relatively high SSSIG and has a strong anti-noise capability. The regular patterns (e.g. checkerboard-type) can also be avoided by the proposed method. Both the simulation and experiment have been conducted to validate the effectiveness of the proposed method. The simulation results show that the standard deviation (STD) of the displacements obtained by using the proposed speckle pattern in this study is reduced by 25.2% and 10.7%, respectively, comparing with the results obtained by the conventional random speckle pattern and the optimized speckle pattern in our earlier work. In addition, the experimental results from a tensile testing also agreed to the results from the simulation.
In this study, an optimal scheduling model is proposed to perform energy management in a microgrid (MG) including distributed energy resources in both grid-connected and islanded modes. To this end, a tri-level optimi...
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In this study, an optimal scheduling model is proposed to perform energy management in a microgrid (MG) including distributed energy resources in both grid-connected and islanded modes. To this end, a tri-level optimization model has been presented, in which Benders method decomposes the original problem into the main problem (the first level), sub-problem (SP) (the second level) and optimal SP (the third level). The first and second levels model the MG operation in grid-connected and islanded modes, respectively. Finally, the third level directs the obtained feasible solution of the second level to an optimal solution in the islanded mode. In the proposed model, the effect of an adjacent MG is also considered, and a call-option contract is used to model the transaction power between networked MG. While it is assumed that they are connected to each other, they only exchange power in the islanded mode to prevent the arbitrage state. The aim of the proposed model is to present a flexible and integrated operation of the MG, which has the ability to work in both grid connected and island modes. Uncertainties of the problem are modelled using the two-point estimation method (2 m+1).
In the process of economic construction, a variety of investment opportunities await the enterprises. And mostly, there are more than one opportunities under consideration in each project. These projects can be mutual...
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In the process of economic construction, a variety of investment opportunities await the enterprises. And mostly, there are more than one opportunities under consideration in each project. These projects can be mutually exclusive, independent , and they can also be a layer of mixed projects, where each independent project have several mutually exclusive alternatives. Whatever, in terms of selecting projects, our main purpose is to maximize the wealth of the enterprise. At the same time, the problem we face while selecting projects is the capital restriction. This article provides two methods, i.e., △PIR method and linear programmingmethod, for selecting beneficial, appropriate and optimal projects from the mixed projects with the capital restriction.
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