Multiobjective Differential Evolution for Higher-Dimensional Multimodal Multiobjective Optimization

In multimodal multiobjective optimization problems(MMOPs),there are several Pareto optimal solutions corre-sponding to the identical objective vector.This paper proposes a new differential evolution algorithm to solve MMOPs with higher-dimensional decision variables.Due to the increase in the dimensions of decision variables in real-world MMOPs,it is diffi-cult for current multimodal multiobjective optimization evolu-tionary algorithms(MMOEAs)to find multiple Pareto optimal solutions.The proposed algorithm adopts a dual-population framework and an improved environmental selection method.It utilizes a convergence archive to help the first population improve the quality of solutions.The improved environmental selection method enables the other population to search the remaining decision space and reserve more Pareto optimal solutions through the information of the first population.The combination of these two strategies helps to effectively balance and enhance conver-gence and diversity performance.In addition,to study the per-formance of the proposed algorithm,a novel set of multimodal multiobjective optimization test functions with extensible decision variables is designed.The proposed MMOEA is certified to be effective through comparison with six state-of-the-art MMOEAs on the test functions.

A Model for Helmet-Wearing Detection of Non-Motor Drivers Based on YOLOv5s

Detecting non-motor drivers’helmets has significant implications for traffic control.Currently,most helmet detection methods are susceptible to the complex background and need more accuracy and better robustness of small object detection,which are unsuitable for practical application scenar-ios.Therefore,this paper proposes a new helmet-wearing detection algorithm based on the You Only Look Once version 5(YOLOv5).First,the Dilated convolution In Coordinate Attention(DICA)layer is added to the backbone network.DICA combines the coordinated attention mechanism with atrous convolution to replace the original convolution layer,which can increase the perceptual field of the network to get more contextual information.Also,it can reduce the network’s learning of unnecessary features in the background and get attention to small objects.Second,the Rebuild Bidirectional Feature Pyramid Network(Re-BiFPN)is used as a feature extraction network.Re-BiFPN uses cross-scale feature fusion to combine the semantic information features at the high level with the spatial information features at the bottom level,which facilitates the model to learn object features at different scales.Verified on the proposed“Helmet Wearing dataset for Non-motor Drivers(HWND),”the results show that the proposed model is superior to the current detection algorithms,with the mean average precision(mAP)of 94.3%under complex background.

An evaluation model for smart grids in support of smart cities based on the Hierarchy of Needs Theory

Smart cities depend highly on an intelligent electrical networks to provide a reliable,safe,and clean power supplies.A smart grid achieves such aforementioned power supply by ensuring resilient energy delivery,which presents opportunities to improve the cost-effectiveness of power supply and minimize environmental impacts.A systematic evaluation of the comprehensive benefits brought by smart grid to smart cities can provide necessary theoretical fundamentals for urban planning and construction towards a sustainable energy future.However,most of the present methods of assessing smart cities do not fully take into account the benefits expected from the smart grid.To comprehensively evaluate the development levels of smart cities while revealing the supporting roles of smart grids,this article proposes a model of smart city development needs from the perspective of residents’needs based on Maslow’s Hierarchy of Needs theory,which serves the primary purpose of building a smart city.By classifying and reintegrating the needs,an evaluation index system of smart grids supporting smart cities was further constructed.A case analysis concluded that smart grids,as an essential foundation and objective requirement for smart cities,are important in promoting scientific urban management,intelligent infrastructure,refined public services,efficient energy utilization,and industrial development and modernization.Further optimization suggestions were given to the city analyzed in the case include strengthening urban management and infrastructure constructions,such as electric vehicle charging facilities and wireless coverage.

熔融沉积成型参数对改性聚乳酸冲击性能的影响

以聚乳酸(PLA)为基体、热塑性聚氨酯(TPU)和甲基丙烯酸甲酯-有机硅-苯乙烯共聚物(S-2001)为增韧剂,通过熔融共混法制备了改性PLA 3D打印线材,采用正交试验探索了底板温度、打印温度、沉积方式、打印层厚和打印速度等熔融沉积成型(FDM)参数对改性PLA冲击性能的影响。结果表明,当底板温度为90℃,喷嘴温度为190℃,沉积方式为45°/45°,打印层厚为0.4 mm和打印速度为45 mm/s时,FDM试样的冲击强度达到最大值,而且打印层厚和沉积方式对改性PLA FDM试样的冲击性能影响显著;扫描电镜分析表明增加打印层厚有利于材料吸收冲击功,奇数层与偶数层之间的不同沉积角度对试样冲击强度的提高影响不一,45°/45°为宜;同时,最优工艺的FDM试样的冲击强度比注塑试样低,为注塑试样的71.4%。

Innovative Practices of Project“Recall”:The Effect of Integration of Employment Big Data Analysis into the Classroom for the Training of Professional Talents

With the emphasis on using technological innovation and digital transformation to generate new development momentum,the Ministry of Education issued the“Code for the Construction of Digital Campuses in Colleges and Universities”in March 2021,which clarified the talent training path for innovative exploration of education mode under the informatization condition.In the process of exploring new methods of talent training models in the digital age,this article uses employment big data to enter the classroom,triggering changes in classroom teaching interaction methods,and then accumulates summary records of a series of research experience,in the hope that more research can extend on this result.

基于熔融沉积成型的聚乳酸/热塑性聚氨酯的制备与表征

通过熔融共混法制备了不同质量比的聚乳酸(PLA)/热塑性聚氨酯(TPU)共混物。采用旋转流变仪、扫描电镜、电子万能试验机及差示扫描量热仪等研究了共混物的动态流变行为、微观形貌、力学性能和热性能,并通过线材机牵引成直径为1.75 mm左右的线材进行熔融沉积成型(FDM)。结果表明,加入TPU后能提高材料的储能模量,使熔体弹性增强,利于熔融铺丝。TPU能改善材料的冲击韧性,且随着TPU含量的增加而增大。另外,PLA/TPU熔融共混后体系的结晶能力下降,对熔融沉积成型收缩翘曲具有抑制作用。当TPU质量分数为10%时,线材的熔融沉积成型效果最好。

The Life Cycle of Knowledge in Big Language Models:A Survey

Knowledge plays a critical role in artificial intelligence.Recently,the extensive success of pre-trained language models(PLMs)has raised significant attention about how knowledge can be acquired,maintained,updated and used by language models.Despite the enormous amount of related studies,there is still a lack of a unified view of how knowledge circulates within language models throughout the learning,tuning,and application processes,which may prevent us from further understanding the connections between current progress or realizing existing limitations.In this survey,we revisit PLMs as knowledge-based systems by dividing the life circle of knowledge in PLMs into five critical periods,and investigating how knowledge circulates when it is built,maintained and used.To this end,we systematically review existing studies of each period of the knowledge life cycle,summarize the main challenges and current limitations,and discuss future directions.

Multicolor^(19)F magnetic resonance imaging:A promising medical technique for in vivo visualization of multiple biological targets

Driven by the needs of precision medicine,current imaging techniques are under continuous development to offer more accurate and comprehensive information beyond traditional macroscopic anatomical images.Multispectral color-coded(multicolor)^(19)F magnetic resonance imaging(MRI)is receiving increasing attention owing to its capability for visualizing quantitative and multiplexed molecular information during various biological processes.The chemical design and preparation of^(19)F probes lie at the core of multicolor^(19)F MRI since their performance dominates the accomplishment of this technique.Herein,the working principles of multicolor^(19)F MRI are briefly introduced.Recent progress on multicolor^(19)F MRI probes for simultaneous in vivo visualization of multiple biological targets is summarized.Finally,current challenges and potential solutions in this fast-developing field are discussed.

Comment on “Acid-induced tunable white light emission based on triphenylamine derivatives”

We comment the recent paper which reported a series of TPA derivatives to show acid-induced tunable white light emission.