If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation.Abstract In this paper, a new density-stiffness interpolation scheme for topology optimization of continuum structures is proposed. Based on this new scheme, not only the so-called checkerboard pattern can be eliminated from the final optimal topology, but also the boundary-smooth effect associated with the traditional sensitivity averaging approach can also be overcome. A proof of the existence of the solution of the optimization problem is also given, therefore mesh independent optimization results can be obtained. Numerical examples illustrate the effectiveness and the advantage of the proposed interpolation scheme. IntroductionTopology optimization is one of the most challenging research topics in the field of structural optimization. It has received more and more research attentions recently because of its great potential of application in many industrial areas. Topology optimization aims at determining the optimum number, positions and mutual connectivity of the structural members. Its importance lies in the fact that the appropriate topology is generally the most decisive factor for the efficiency of a product. For topology optimization of continuum structures, homogenization or variable density based approaches are often employed. In homogenization (or microstructure) based approach, the well-posedness of the topology optimization is achieved by introducing the porous materials with microstructure into the optimization model. The effective macroscopic properties of the porous materials are computed by applying some smear-out techniques. These effective properties are closely related to the microscopic geometry parameters, thus we can optimize the structural topology by adjusting these parameters. In variable density approach, a density

The miscoordination and malfunctioning of directional overcurrent relays (DOCR) may occur due to a significant change in the fault current level (FCL) and a change in the network topology, from a radial to ring topology, caused by renewable energy resource-based distributed generation (RES-DG). In this paper, a hybrid time–current–voltage (TCV)-based protection scheme is proposed to eliminate the DOCR miscoordination and to reduce the overall operation time of DOCRs. The DOCR coordination problem is solved with alpha Harris Hawks optimization (α-HHO). Detailed numerical studies are carried out, and to show the performance of the proposed scheme, the results are compared with the existing protection schemes in the recent literature.

In recent years, with the global recognition of the concept of sustainable development, the international market attaches great importance to the Environment, Society, and Governance (ESG) investment performance of enterprises. The “carbon peaking and carbon neutrality” goal puts forward requirements for Chinese enterprises to carry out ESG investment. As a large state-owned enterprise in China, power grid companies need to take the lead in ESG investment. Based on the System Dynamics (SD) theory, this paper establishes the simulation model of ESG-responsible investment of power grid companies, including the environmental investment sub-module, social investment sub-module, and governance investment sub-module. Taking a provincial Power Grid Company as an example, the numerical simulation of ESG investment of power grid companies is carried out. The actual input-output efficiency of ESG investment of power grid companies is reflected through the mapping relationship between key indicators and investment amount, and the ESG investment scale and investment weight of the Power Company in the coming years are predicted. Compared with the traditional static analysis method, this model can provide a theoretical basis for power grid companies to carry out ESG investment decisions.

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