Multitasking Evolutionary Algorithm Based on Adaptive Seed Transfer for Combinatorial Problem

Evolutionary computing (EC) is widely used in dealing with combinatorial optimization problems (COP). Traditional EC methods can only solve a single task in a single run, while real-life scenarios often need to solve multiple COPs simultaneously. In recent years, evolutionary multitasking optimization (EMTO) has become an emerging topic in the EC community. And many methods have been designed to deal with multiple COPs concurrently through exchanging knowledge. However, many-task optimization, cross-domain knowledge transfer, and negative transfer are still significant challenges in this field. A new evolutionary multitasking algorithm based on adaptive seed transfer (MTEA-AST) is developed for multitasking COPs in this work. First, a dimension unification strategy is proposed to unify the dimensions of different tasks. And then, an adaptive task selection strategy is designed to capture the similarity between the target task and other online optimization tasks. The calculated similarity is exploited to select suitable source tasks for the target one and determine the transfer strength. Next, a task transfer strategy is established to select seeds from source tasks and correct unsuitable knowledge in seeds to suppress negative transfer. Finally, the experimental results indicate that MTEA-AST can adaptively transfer knowledge in both same-domain and cross-domain many-task environments. And the proposed method shows competitive performance compared to other state-of-the-art EMTOs in experiments consisting of four COPs

The Low-Carbon City Pilot Policy and Urban Land Use Efficiency:A Policy Assessment from China

Against the backdrop of severe global warming, the low-carbon city pilot policy, with carbon emission reduction as its main objective, is an important initiative for China to fulfil its international commitment to carbon emission reduction and promote a green and low-carbon development strategy. However, none of the literature has yet evaluated whether the pilot low-carbon city policy promotes urban land use efficiency as a policy effect. In view of this, this paper measures urban land use efficiency from a low-carbon perspective using a global reference super-efficiency SBM model based on data from 186 prefecture-level cities in China from 2005–2017, and subsequently constructs a difference-in-differences method to test the true impact of low-carbon city pilot policies on urban land use efficiency and carbon emissions, and uses a propensity score matching method to test its robustness. It is found that: (1) the average level of urban land use efficiency in China is low and on a downward trend; (2) overall, cities are predominantly low-efficiency cities, with only the high-efficiency cities in Guangdong Province showing spatial agglomeration; and (3) the low-carbon city pilot policy reduces carbon emissions while also negatively affecting urban land use efficiency. Accordingly, this paper puts forward corresponding policy recommendations

Impact of hyper-elasticity on cyclic sand modelling: A numerical study based on SANISAND-MS

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Accounting for effects of cyclic loading in design of offshore wind turbine foundations

In the design of foundations for offshore structures, it is generally important and required to consider the effects of cyclic loading caused by waves and wind. Therefore, NGI has developed a framework since the early 1970s that has been utilized in the design of various offshore structures. However, there are currently no accepted guidelines on how to account for this effect in design of monopile foundations. With the introduction of large-diameter monopile foundations for offshore wind turbines, it has become necessary to revisit and modify our existing procedure. The primary difference between monopile foundations for offshore wind turbines and those for the oil and gas industry is that the design of the former is typically not governed by a global failure mechanism during extreme storm loading because of their rather ductile response. Additionally, offshore wind parks often consist of over one hundred turbines, which necessitates more efficient design methods to optimise each individual foundation within a huge field with varying soil stratigraphy. This paper presents an efficient procedure using the finite element method to account for the effects of cyclic loading in design of monopile foundations. Furthermore, it provides recommendations for further improvements.publishedVersio

VKIE: The Application of Key Information Extraction on Video Text

Extracting structured information from videos is critical for numerous downstream applications in the industry. In this paper, we define a significant task of extracting hierarchical key information from visual texts on videos. To fulfill this task, we decouples it into four subtasks and introduce two implementation solutions called PipVKIE and UniVKIE. PipVKIE sequentially completes the four subtasks in continuous stages, while UniVKIE is improved by unifying all the subtasks into one backbone. Both PipVKIE and UniVKIE leverage multimodal information from vision, text, and coordinates for feature representation. Extensive experiments on one well-defined dataset demonstrate that our solutions can achieve remarkable performance and efficient inference speed. The code and dataset will be publicly available

Load history idealization effects for design of monopiles in clay

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