Constraints Separation Based Evolutionary Multitasking for Constrained Multi-Objective Optimization Problems

Constrained multi-objective optimization problems(CMOPs)generally contain multiple constraints,which not only form multiple discrete feasible regions but also reduce the size of optimal feasible regions,thus they propose serious challenges for solvers.Among all constraints,some constraints are highly correlated with optimal feasible regions;thus they can provide effective help to find feasible Pareto front.However,most of the existing constrained multi-objective evolutionary algorithms tackle constraints by regarding all constraints as a whole or directly ignoring all constraints,and do not consider judging the relations among constraints and do not utilize the information from promising single constraints.Therefore,this paper attempts to identify promising single constraints and utilize them to help solve CMOPs.To be specific,a CMOP is transformed into a multitasking optimization problem,where multiple auxiliary tasks are created to search for the Pareto fronts that only consider a single constraint respectively.Besides,an auxiliary task priority method is designed to identify and retain some high-related auxiliary tasks according to the information of relative positions and dominance relationships.Moreover,an improved tentative method is designed to find and transfer useful knowledge among tasks.Experimental results on three benchmark test suites and 11 realworld problems with different numbers of constraints show better or competitive performance of the proposed method when compared with eight state-of-the-art peer methods.

A deep multimodal fusion and multitasking trajectory prediction model for typhoon trajectory prediction to reduce flight scheduling cancellation

Natural events have had a significant impact on overall flight activity,and the aviation industry plays a vital role in helping society cope with the impact of these events.As one of the most impactful weather typhoon seasons appears and continues,airlines operating in threatened areas and passengers having travel plans during this time period will pay close attention to the development of tropical storms.This paper proposes a deep multimodal fusion and multitasking trajectory prediction model that can improve the reliability of typhoon trajectory prediction and reduce the quantity of flight scheduling cancellation.The deep multimodal fusion module is formed by deep fusion of the feature output by multiple submodal fusion modules,and the multitask generation module uses longitude and latitude as two related tasks for simultaneous prediction.With more dependable data accuracy,problems can be analysed rapidly and more efficiently,enabling better decision-making with a proactive versus reactive posture.When multiple modalities coexist,features can be extracted from them simultaneously to supplement each other’s information.An actual case study,the typhoon Lichma that swept China in 2019,has demonstrated that the algorithm can effectively reduce the number of unnecessary flight cancellations compared to existing flight scheduling and assist the new generation of flight scheduling systems under extreme weather.

Evolutionary Multitasking With Global and Local Auxiliary Tasks for Constrained Multi-Objective Optimization

Constrained multi-objective optimization problems(CMOPs) include the optimization of objective functions and the satisfaction of constraint conditions, which challenge the solvers.To solve CMOPs, constrained multi-objective evolutionary algorithms(CMOEAs) have been developed. However, most of them tend to converge into local areas due to the loss of diversity. Evolutionary multitasking(EMT) is new model of solving complex optimization problems, through the knowledge transfer between the source task and other related tasks. Inspired by EMT, this paper develops a new EMT-based CMOEA to solve CMOPs, in which the main task, a global auxiliary task, and a local auxiliary task are created and optimized by one specific population respectively. The main task focuses on finding the feasible Pareto front(PF), and global and local auxiliary tasks are used to respectively enhance global and local diversity. Moreover, the global auxiliary task is used to implement the global search by ignoring constraints, so as to help the population of the main task pass through infeasible obstacles. The local auxiliary task is used to provide local diversity around the population of the main task, so as to exploit promising regions. Through the knowledge transfer among the three tasks, the search ability of the population of the main task will be significantly improved. Compared with other state-of-the-art CMOEAs, the experimental results on three benchmark test suites demonstrate the superior or competitive performance of the proposed CMOEA.

基于Multitask⁃YOLO网络的卫星帆板ISAR图像快速分割

随着空间技术的飞速发展,空间态势感知能力需求不断增加。与传统光学传感器相比,逆合成孔径雷达(Inverse synthetic aperture radar,ISAR)具有全天候、远距离高分辨率成像的能力,且成像不受光照条件的影响。此外,空间态势感知系统需要对周围航天器进行准确的评估,因此对空间目标部件识别能力的需求日益迫切。本文提出了一种基于YOLOv5结构的Multitask⁃YOLO网络,用于卫星ISAR图像中卫星帆板的识别和分割。首先,本文添加了分割解耦头来实现网络的分割功能。然后用空间金字塔池快速算法(Spatial pyramid pooling fast,SPPF)和距离交并比算法(Distance intersection over union,DIoU)代替原有结构,避免图像失真,加快收敛速度。通过在通道中引入注意机制,提高了分割和识别的准确性。最后使用模拟卫星的ISAR图像进行实验。结果表明,所提出的Multitask⁃YOLO网络高效、准确地实现了部件的识别和分割。与其他的识别和分割网络相比,该网络的平均精度(mean Average precision,mAP)和平均交并比(mean Intersection over union,mIoU)提高了约5%。此外,该网络的运行速度高达16.4 GFLOP,优于传统的多任务网络的性能。

The Application of Multitasking Mechanism in Single Chip Computer System

Developed a new program structure using in single chip computer system, which based on multitasking mechanism. Discussed the specific method for realization of the new structure. The applied sample is also provided.

Performance Analysis of Robotic Arm Manipulators Control System under Multitasking Environment

This work is to observe the performance of PC based robot manipulator under general purpose （Windows）, Soft （Linux） and Hard （RT Linux） Real Time Operating Systems （OS）. The same open loop control system is observed in different operating systems with and without multitasking environment. The Data Acquisition （DAQ, PLC-812PG） card is used as a hardware interface. From the experiment, it could be seen that in the non real time operating system （Windows）, the delay of the control system is larger than the Soft Real Time OS （Linux）. Further, the authors observed the same control system under Hard Real Time OS （RT-Linux）. At this point, the experiment showed that the real time error （jitter） is minimum in RT-Linux OS than the both of the previous OS. It is because the RT-Linux OS kernel can set the priority level and the control system was given the highest priority. The same experiment was observed under multitasking environment and the comparison of delay was similar to the preceding evaluation.

An improved adaptive differential evolution algorithm for single unmanned aerial vehicle multitasking

Single unmanned aerial vehicle(UAV)multitasking plays an important role in multiple UAVs cooperative control,which is as well as the most complicated and hardest part.This paper establishes a threedimensional topographical map,and an improved adaptive differential evolution(IADE)algorithm is proposed for single UAV multitasking.As an optimized problem,the efficiency of using standard differential evolution to obtain the global optimal solution is very low to avoid this problem.Therefore,the algorithm adopts the mutation factor and crossover factor into dynamic adaptive functions,which makes the crossover factor and variation factor can be adjusted with the number of population iteration and individual fitness value,letting the algorithm exploration and development more reasonable.The experimental results implicate that the IADE algorithm has better performance,higher convergence and efficiency to solve the multitasking problem compared with other algorithms.

From Rubbish to a Large Scale Industry： A Simple Fabrication of Superfiber with Multitasking Applications

In the whole earth, people increased dramatically from generation to generation which had created a large scale of broken environment so that people are facing more various types of garbage. Most of garbages are not useful and as a matter of fact, they are used to be neglected. Furthermore, many efforts have been conducted to change it by many types of recycled methods. Here, a simple technique is proposed with and without using fires to transform the useless natural or man-made rubbish things to be a superfiber as well as thin film with multitasking applications in human daily life. Since most of earth environment is covered by oceans, here the authors show how the ocean related garbage such as the crab skins, broken coral reefs and beach stones were changed to be superfiber and a multitasking device prototype.

Optimal Design of a Ship Multitasking Cabin Layout Based on the Interval Optimization Method

Searching for the optimal cabin layout plan is an efective way to improve the efciency of the overall design and reduce a ship’s operation costs.The multitasking states of a ship involve several statuses when facing diferent missions during a voyage,such as the status of the marine supply and emergency escape.The human fow and logistics between cabins will change as the state changes.An ideal cabin layout plan,which is directly impacted by the above-mentioned factors,can meet the diferent requirements of several statuses to a higher degree.Inevitable deviations exist in the quantifcation of human fow and logistics.Moreover,uncontrollability is present in the fow situation during actual operations.The coupling of these deviations and uncontrollability shows typical uncertainties,which must be considered in the design process.Thus,it is important to integrate the demands of the human fow and logistics in multiple states into an uncertainty parameter scheme.This research considers the uncertainties of adjacent and circulating strengths obtained after quantifying the human fow and logistics.Interval numbers are used to integrate them,a two-layer nested system of interval optimization is introduced,and diferent optimization algorithms are substituted for solving calculations.The comparison and analysis of the calculation results with deterministic optimization show that the conclusions obtained can provide feasible guidance for cabin layout scheme.

Multitasking Behavior and Perceptions of Academic Performance in University Business Students in Mexico during the COVID-19 Pandemic

The current study measures the influence of multitasking behavior and self-efficacy for self-regulated learning(SESRL)on perceptions of academic performance and views in university students during the COVID-19 pan-demic in Mexico.264 university students fulfilled an online questionnaire.It was observed that multitasking beha-vior negatively influences SESRL(-0.203),while SESRL showed a positive influence of 0.537 on perceptions of academic performance,and multitasking behavior had an influence of-0.097 on the perception of academic per-formance.Cronbach’s alpha and Average Variance Extracted values were 0.809 and 0.577(multitasking behavior),0.819 and 0.626(SESRL),0.873 and 0.725(perceptions of academic performance),respectively.The results of the bootstrapping test showed that the path coefficients were significant.The study outcomes can support new plans in universities to ensure the best academic outcomes.Our study showed evidence of the COVID-19 impact on education behavior.This study’s novelty is based on using the partial least square structural equation modeling(PLS-SEM)technique to evaluate these variables.

Evolutionary Multitask Optimization in Real-World Applications: A Survey

Because of its strong ability to solve problems,evolutionary multitask optimization(EMTO)algorithms have been widely studied recently.Evolutionary algorithms have the advantage of fast searching for the optimal solution,but it is easy to fall into local optimum and difficult to generalize.Combining evolutionary multitask algorithms with evolutionary optimization algorithms can be an effective method for solving these problems.Through the implicit parallelism of tasks themselves and the knowledge transfer between tasks,more promising individual algorithms can be generated in the evolution process,which can jump out of the local optimum.How to better combine the two has also been studied more and more.This paper explores the existing evolutionary multitasking theory and improvement scheme in detail.Then,it summarizes the application of EMTO in different scenarios.Finally,according to the existing research,the future research trends and potential exploration directions are revealed.

BIM Supporting the Development of Multitasks Related with the Structural Project

Building Information Modelling (BIM) is a methodology focused on the centralization and sharing of the project information among all professionals involved, supported on the generation and manipulation of a three-dimensional (3D) digital BIM model. This methodology allows a close collaboration between the architect and the structural engineer and an adequate manipulation of the structural BIM model database, on the definition of multitasks. The collaboration allowed between all disciplines, avoid the detection of conflicts and data omission after in the construction place. Two BIM structural design cases were developed, using Revit as the modelling system and Robot as the structural software. Concerning the structural project the interoperability capacity between the software is still a limitation that engineers must be warned of. In the present study, the benefits and limitations identified within the communication and integration of distinct disciplines and on the development of most frequent multitasks normally related with a structural project, were considered.

面向合同信息抽取的动态多任务学习方法

对于合同文本中要素和条款两类信息的准确提取,可以有效提升合同的审查效率,为贸易各方提供便利化服务.然而当前的合同信息抽取方法一般训练单任务模型对要素和条款分别进行抽取,并没有深挖合同文本的特征,忽略了不同任务间的关联性.因此,采用深度神经网络结构对要素抽取和条款抽取两个任务间的相关性进行研究,并提出多任务学习方法.所提方法首先将上述两种任务进行融合,构建一种应用于合同信息抽取的基本多任务学习模型;然后对其进行优化,利用Attention机制进一步挖掘其相关性,形成基于Attention机制的动态多任务学习模型;最后针对篇章级合同文本中复杂的语义环境,在前两者的基础上提出一种融合词汇知识的动态多任务学习模型.实验结果表明,所提方法可以充分捕捉任务间的共享特征,不仅取得了比单任务模型更好的信息抽取结果,而且能够有效解决合同文本中要素与条款间实体嵌套的问题,实现合同要素与条款的信息联合抽取.此外,为了验证该方法的鲁棒性,在多个领域的公开数据集上进行实验,结果表明该方法的效果均优于基线方法.

“三心二意”胜过“一心一意”:媒体多任务提升低工作记忆容量者创造力

数字时代,媒体多任务已然渗透人类生活方方面面。但以往研究主要探讨其消极影响,忽视媒体多任务暗藏激发创造力的可能。基于创造力的坚持−灵活双通道理论,通过3个仿真行为实验,考察了媒体多任务对创造力的促进作用以及心智游移与工作记忆容量在其中的中介和调节作用。结果发现:相比非媒体多任务,个体进行媒体多任务时表现出更高的创造力(实验1),其心理机制是媒体多任务诱发更高的心智游移频率,进而提升创造力(实验1和实验2),且这一提升效应只存在于低工作记忆容量组,高工作记忆容量组中则表现为消极影响(实验3)。研究结果对揭示媒体多任务的积极功能,拓展坚持−灵活交互视角以弥补双通道理论平行视角缺陷,帮助不同特质个体有效利用媒体多任务提升创造力均有重要的启示价值。

融合RoBERTa-GCN-Attention的隐喻识别与情感分类模型

在隐喻识别与隐喻情感分类任务的联合研究中,现有多任务学习模型存在对隐喻语料中的上下文语义信息和句法结构信息提取不够准确,并且缺乏对粗细两种粒度信息同时捕捉的问题.针对第1个问题,首先改进了传统的RoBERTa模型,在原有的自注意力机制中引入上下文信息,以此提取上下文中重要的隐喻语义特征;其次在句法依存树上使用图卷积网络提取隐喻句中的句法结构信息.针对第2个问题,使用双层注意力机制,分别聚焦于单词和句子层面中对隐喻识别和情感分类有贡献的特征信息.在两类任务6个数据集上的对比实验结果表明,该模型相比基线模型性能均有提升.

基于多特征重构的三维目标反演算法

为了解决基于深度学习的三维反演方法中存在的内存占用大、训练耗时久的问题,提出基于多特征重构的三维目标反演算法.通过特征分解提取目标的水平区域、中心深度、垂直厚度和剩余密度4类特征,实现对三维模型的压缩,降低内存占用.设计多特征重构反演网络(MRNet),通过不同的Decoder实现对目标4类特征的预测,利用4类特征重构三维模型,实现对三维目标的反演.在网络输入端引入梯度联合实现对目标边界信息的增强.在跨层连接处引入CA注意力机制,实现对Decoder预测功能的分化,优化反演效果.模拟实验结果显示,MRNet的局部相对准确度相对于3D U-Net提升了30%以上,达到88.91%,每轮训练时间仅为3D U-Net的1/13.将MRNet应用于Vinton盐丘地区,较准确地得到了盖岩的分布情况,验证了MRNet具备一定的泛化性.

基于Go/No-Go范式的多任务操作实验评估军校学员的反应抑制能力

目的探索军校学员在多任务操作情境中的反应抑制能力特点。方法选择127名军校学员作为被试,采用Go/No-Go范式进行测试,通过重复测量方差分析和分布检验等方法探索模拟驾驶任务的干扰对被试Go/No-Go测试表现的影响。结果对127名被试的测试结果显示,在击中率和虚报率上存在干扰任务和Go试次比例的交互作用,即在没有干扰任务时60%试次比例与40%试次比例条件下被试的击中率和虚报率差异无统计学意义(均P>0.05),而在有干扰任务时60%试次比例条件下被试的击中率和虚报率大于40%试次比例条件(均P<0.01)。在击中率、虚报率和辨别力指标d’上干扰任务的主效应显著(均P<0.01),即干扰任务降低了被试的击中率和辨别力、增大了虚报率。不同被试在有无干扰任务时辨别力的变化不同,根据无干扰任务与有干扰任务时辨别力指标d’的差值的平均数加减1个标准差,可将被试分为易受干扰组23人(18.11%)、不易受干扰组20人(15.75%)和中间组84人(66.14%)。结论干扰任务增加了军校学员在多任务操作时的心理负荷,降低了其反应抑制能力,且军校学员的反应抑制能力存在个体差异。

面向类不均衡数据的多任务博弈概率分类向量机

在工程实际中获取的故障样本往往会呈现不均衡特点,同时传统的分类模型也会存在局限性。针对这些问题,基于稀疏贝叶斯理论、模糊隶属度等理论,提出了一种多任务博弈概率分类向量机(MGPCVM)分类方法。首先,在MGPCVM的目标函数中,设计了博弈因子,将不同类样本质心间的博弈信息赋予每个样本特定的样本质心敏感值,以解决传统分类器对不平衡数据集分类表现较差的问题;然后,在贝叶斯框架理论下,采用截断高斯先验分布的方法,使样本参数的正负与对应的标签信息相一致,且使样本质心敏感值产生了稀疏估计;最后,将MGPCVM方法应用于两种不同实验平台采集的滚动轴承实验数据处理,进行了故障诊断有效性验证。研究结果表明:在不同的不平衡比(IR)下,MGPCVM方法的准确率均保持在95%以上,相对于支持向量机(SVM)、概率分类向量机(PCVM)等方法提升了4%~8%;与典型向量式分类方法相比,MGPCVM方法可以在不平衡数据条件下表现出优越的分类性能,适用于实际工况中数据失衡的分类问题。

多任务快速切换工业机器人实训平台技术研究

为了提高现有工业机器人实训平台的教学效率,实现多个教学任务快速切换,提出一种基于模块化可重构设计思想的工业机器人实训平台,首先利用模块划分和模糊聚类相关理论对实训系统进行模块划分,确定最佳划分方案;其次,分别从机械、硬件、控制等层次进行模块化可重构设计,实现底层硬件快速重构;编写上位机软件并对实训系统及进行运行测试,实现对各个模块的控制,在多个实训任务环境下,控制硬件模块实现快速重构,提高教学效率。

多任务优化算法及应用研究综述

进化多任务优化(EMTO)是进化计算中一种新型方法,它可以同时解决多个相关的优化任务,并通过任务之间的知识转移增强每个任务的优化。近年来,越来越多的进化多任务优化相关研究致力于利用它强大的并行搜索能力和降低计算成本的潜力优化各种问题,并且EMTO已应用于各种各样的实际场景当中。从EMTO的原理、核心设计、应用以及挑战四个方面对EMTO的算法及应用进行了讨论。首先介绍了EMTO的大致分类,分别从两个层次、四个方面介绍,包括单种群多任务、多种群多任务、辅助任务形式以及多形式任务形式;其次介绍EMTO的核心组件设计,包括任务构建以及知识转移;最后对它的各种应用场景进行介绍,并对今后研究做了总结与展望。