Multi‐objective particle swarm optimisation of complex product change plan considering service performance

Design change is an inevitable part of the product development process.This study proposes an improved binary multi‐objective PSO algorithm guided by problem char-acteristics(P‐BMOPSO)to solve the optimisation problem of complex product change plan considering service performance.Firstly,a complex product multi‐layer network with service performance is established for the first time to reveal the impact of change effect propagation on the product service performance.Secondly,the concept of service performance impact(SPI)is defined by decoupling the impact of strongly associated nodes on the service performance in the process of change affect propagation.Then,a triple‐objective selection model of change nodes is established,which includes the three indicators:SPI degree,change cost,and change time.Furthermore,an integer multi‐objective particle swarm optimisation algorithm guided by problem characteristics is developed to solve the model above.Experimental results on the design change problem of a certain type of Skyworth TV verify the effectiveness of the established optimisation model and the proposed P‐BMOPSO algorithm.

Enhancing pain modulation: the efficacy of synchronous combination of virtual reality and transcutaneous electrical nerve stimulation

Introduction Virtual reality(VR)and transcutaneous electrical nerve stimulation(TENS)have emerged as effective interventions for pain reduction.However,their standalone applications often yield limited analgesic effects,particularly in certain painful conditions.Aims Our hypothesis was that the combination of VR with TENS in a synchronous manner could produce the best analgesic effect among the four experimental conditions.Methods To address this challenge,we proposed a novel pain modulation strategy that synchronously combines VR and TENS,aiming to capitalise on both techniques'complementary pain modulation mechanisms.Thirty-two healthy subjects participated in the study and underwent three types of interventions:VR alone,a combination of VR with conventional TENS,and a combination of VR with synchronous TENS.Additionally,a control condition with no intervention was included.Perceived pain intensity,pain unpleasantness,positive and negativeaffect scores,and electroencephalographic(EEG)data were collected before and after the interventions.To delve into the potential moderating role of pain intensity on the analgesic efficacy of VR combined with synchronous TENS,we incorporated two distinct levels of painful stimuli:one representing mild to moderate pain(ie,low pain)and the other representing moderate to severe pain(ie,high pain).Results Our findings revealed that both combination interventions exhibited superior analgesic effects compared with the VR-alone intervention when exposed to low and high pain stimuli.Notably,the combination of VR with synchronous TENS demonstrated greater analgesic efficacy than the combination of VR with conventional TENS.EEG data further supported these results,indicating that both combination interventions elicited a greater reduction in event-related potential magnitude compared with the VR-alone intervention during exposure to low and high pain stimuli.Moreover,the synchronous combination intervention induced a more significant reduction in N2 amplitude than the VR-alone intervention during exposure to low pain stimuli.No significant differences in EEG response changes were detected between the two combination interventions.Both combination interventions resulted in a greater reduction in negative affect compared with the VR-alone intervention.Conclusions Altogether,our study highlights the effectiveness of the synchronous combination of VR and TENS in enhancing pain modulation.These findings offer valuable insights for developing innovative pain treatments,emphasising the importance of tailored and multifaceted therapeutic approaches for various painful conditions.

Modulatory effects of transcutaneous auricular vagus nerve stimulation (taVNS) on attentional processes

Background The modulatory effect of transcutaneous auricular vagus nerve stimulation(taVNS)on attention has varied in previous studies.This inconsistency might be attributed to the combined influence of the modulation effect on the different attentional functions,including alerting,orienting and executive control.Aims We aimed to preliminarily examine the modulatory effectsoftaVNS on differentattentionalfunctions.Methods Fifty-nine healthy participants were recruited and were randomly assigned to taVNS(receiving taVNS for 20 minutes)or control(receiving taVNS for 30 seconds)groups.All participants underwent a dot-probe task before and after the taVNS/control intervention.Their behavioural performance and electroencephalographic signals during pre-and post-tests were recorded,and different observed variables were extracted and analysed to characterise different attentional systems.Results We observed that active taVNS applied at the left ear significantly improved the overall behavioural performance,that is,shorter reaction time(RT)and lower intra-individual reaction time variability(lIRTV)for right-hand responses when compared with the control condition.In addition,active taVNS resulted in larger P3 and movement-related cortical potential(MRCP)amplitudes associated with right-hand reactions than the control condition.Active taVNS also decreased the difference between the pre-and post-tests in the power spectral density of spontaneous high-αband oscillations at C4 electrode.Importantly,parallel mediation models for right-hand responses showed that the change of P3 amplitude mediated the effects of taVNS on RT and lIRTV.In contrast,the change of MRCP amplitude suppressed the effect of taVNS on the lIRTV.Conclusions Our results provided behavioural and brain evidence supporting the effects of taVNS on different attentional systems,and their interaction further shaped behavioural performance,suggesting a promising role of taVNS in cognitive enhancement.