Contribution of glial cells to the neuroprotective effects triggered by repetitive magnetic stimulation:a systematic review

Repetitive transcranial magnetic stimulation has been increasingly studied in different neurological diseases,and although most studies focus on its effects on neuronal cells,the contribution of nonneuronal cells to the improvement trigge red by repetitive transcranial magnetic stimulation in these diseases has been increasingly suggested.To systematically review the effects of repetitive magnetic stimulation on non-neuronal cells two online databases.Web of Science and PubMed were searched fo r the effects of high-frequency-repetitive transcranial magnetic stimulation,low-frequencyrepetitive transcranial magnetic stimulation,intermittent theta-bu rst stimulation,continuous thetaburst stimulation,or repetitive magnetic stimulation on non-neuronal cells in models of disease and in unlesioned animals or cells.A total of 52 studies were included.The protocol more frequently used was high-frequency-repetitive magnetic stimulation,and in models of disease,most studies report that high-frequency-repetitive magnetic stimulation led to a decrease in astrocyte and mic roglial reactivity,a decrease in the release of pro-inflammatory cyto kines,and an increase of oligodendrocyte proliferation.The trend towards decreased microglial and astrocyte reactivity as well as increased oligodendrocyte proliferation occurred with intermittent theta-burst stimulation and continuous theta-burst stimulation.Few papers analyzed the low-frequency-repetitive transcranial magnetic stimulation protocol,and the parameters evaluated were restricted to the study of astrocyte reactivity and release of pro-inflammatory cytokines,repo rting the absence of effects on these paramete rs.In what concerns the use of magnetic stimulation in unlesioned animals or cells,most articles on all four types of stimulation reported a lack of effects.It is also important to point out that the studies were developed mostly in male rodents,not evaluating possible diffe rential effects of repetitive transcranial magnetic stimulation between sexes.This systematic review supports that thro ugh modulation of glial cells repetitive magnetic stimulation contributes to the neuroprotection or repair in various neurological disease models.Howeve r,it should be noted that there are still few articles focusing on the impact of repetitive magnetic stimulation on non-neuronal cells and most studies did not perform in-depth analyses of the effects,emphasizing the need for more studies in this field.

High-frequency repetitive transcranial magnetic stimulation promotes neural stem cell proliferation after ischemic stroke

Prolife ration of neural stem cells is crucial for promoting neuronal regeneration and repairing cerebral infarction damage.Transcranial magnetic stimulation(TMS)has recently emerged as a tool for inducing endogenous neural stem cell regeneration,but its underlying mechanisms remain unclea r In this study,we found that repetitive TMS effectively promotes the proliferation of oxygen-glucose deprived neural stem cells.Additionally,repetitive TMS reduced the volume of cerebral infa rction in a rat model of ischemic stro ke caused by middle cerebral artery occlusion,im p roved rat cognitive function,and promoted the proliferation of neural stem cells in the ischemic penumbra.RNA-sequencing found that repetitive TMS activated the Wnt signaling pathway in the ischemic penumbra of rats with cerebral ischemia.Furthermore,PCR analysis revealed that repetitive TMS promoted AKT phosphorylation,leading to an increase in mRNA levels of cell cycle-related proteins such as Cdk2 and Cdk4.This effect was also associated with activation of the glycogen synthase kinase 3β/β-catenin signaling pathway,which ultimately promotes the prolife ration of neural stem cells.Subsequently,we validated the effect of repetitive TMS on AKT phosphorylation.We found that repetitive TMS promoted Ca2+influx into neural stem cells by activating the P2 calcium channel/calmodulin pathway,thereby promoting AKT phosphorylation and activating the glycogen synthase kinase 3β/β-catenin pathway.These findings indicate that repetitive TMS can promote the proliferation of endogenous neural stem cells through a Ca2+influx-dependent phosphorylated AKT/glycogen synthase kinase 3β/β-catenin signaling pathway.This study has produced pioneering res ults on the intrinsic mechanism of repetitive TMS to promote neural function recove ry after ischemic stro ke.These results provide a stro ng scientific foundation for the clinical application of repetitive TMS.Moreover,repetitive TMS treatment may not only be an efficient and potential approach to support neurogenesis for further therapeutic applications,but also provide an effective platform for the expansion of neural stem cells.

Development of a high-repetition-rate lumped-inductance kicker magnet prototype for the beam switchyard of SHINE

The Shanghai high-repetition-rate X-ray free-electron laser and extreme light facility(SHINE)operates at a maximum repetition rate of 1 MHz.Kicker magnets are key components that distribute electron bunches into three different undulator lines in a bunch-by-bunch mode.The kicker field width must be less than the time interval between bunches.A lumpedinductance kicker prototype was developed using a vacuum chamber with a single-turn coil.The full magnetic field strength was 0.005 T.This paper presents the requirements,design considerations,design parameters,magnetic field calculations,and measurements of the kicker magnets.The relevant experimental results are also presented.The pulse width of the magnetic field was approximately 600 ns,and the maximum operation repetition rate was 1 MHz.The developed kicker satisfies the requirements for the SHINE project.Finally,numerous recommendations for the future optimization of kicker magnets are provided.

Evaluation of the coefficient of lateral stress at rest of granular materials under repetitive loading conditions

Although the internal stress state of soils can be affected by repetitive loading,there are few studies evaluating the lateral stress(or K_(0))of soils under repetitive loading.This study investigates the changes in K_(0) and directional shear wave velocity(V_(s))in samples of two granular materials with different particle shapes during repetitive loading.A modified oedometer cell equipped with bender elements and a diaphragm transducer was developed to measure the variations in the lateral stress and the shear wave velocity,under repetitive loading on the loading and unloading paths.The study produced the following results:(1)Repetitive loading on the loading path resulted in an increase in the K_(0) of test samples as a function of cyclic loading number(i),and(2)Repetitive loading on the unloading path resulted in a decrease in K_(0) according to i.The shear wave velocity ratio(i.e.V_(s)(HH)/V_(s)(VH),where the first and second letters in parentheses corresponds to the directions of wave propagation and particle motion,respectively,and V and H corresponds to the vertical and horizontal directions,respectively)according to i supports the experimental observations of this study.However,when the tested material was in lightly over-consolidated state,there was an increase in K_(0) during repetitive loading,indicating that it was the initial K_(0),rather than the loading path,which is responsible for the change in K_(0).The power model can capture the variation in the K_(0) of samples according to i.Notably,the K_(0)=1 line acts as the boundary between the increase and decrease in K_(0) under repetitive loading.

Repetitive transcranial magnetic stimulation in Alzheimer’s disease:effects on neural and synaptic rehabilitation

Alzheimer’s disease is a neurodegenerative disease resulting from deficits in synaptic transmission and homeostasis.The Alzheimer’s disease brain tends to be hyperexcitable and hypersynchronized,thereby causing neurodegeneration and ultimately disrupting the operational abilities in daily life,leaving patients incapacitated.Repetitive transcranial magnetic stimulation is a cost-effective,neuro-modulatory technique used for multiple neurological conditions.Over the past two decades,it has been widely used to predict cognitive decline;identify pathophysiological markers;promote neuroplasticity;and assess brain excitability,plasticity,and connectivity.It has also been applied to patients with dementia,because it can yield facilitatory effects on cognition and promote brain recovery after a neurological insult.However,its therapeutic effectiveness at the molecular and synaptic levels has not been elucidated because of a limited number of studies.This study aimed to characterize the neurobiological changes following repetitive transcranial magnetic stimulation treatment,evaluate its effects on synaptic plasticity,and identify the associated mechanisms.This review essentially focuses on changes in the pathology,amyloidogenesis,and clearance pathways,given that amyloid deposition is a major hypothesis in the pathogenesis of Alzheimer’s disease.Apoptotic mechanisms associated with repetitive transcranial magnetic stimulation procedures and different pathways mediating gene transcription,which are closely related to the neural regeneration process,are also highlighted.Finally,we discuss the outcomes of animal studies in which neuroplasticity is modulated and assessed at the structural and functional levels by using repetitive transcranial magnetic stimulation,with the aim to highlight future directions for better clinical translations.

Alzheimer's disease with depressive symptoms: Clinical effect of intermittent theta burst stimulation repetitive transcranial magnetic stimulation

BACKGROUND Alzheimer's disease(AD),characterized by the ongoing deterioration of neural function,often presents alongside depressive features and greatly affects the quality of life of individuals living with the condition.Although several treatment methods exist,their efficacy is limited.In recent years,repetitive transcranial magnetic stimulation(rTMS)utilizing the theta burst stimulation(TBS)mode,specifically the intermittent TBS(iTBS),has demonstrated promising therapeutic potential in the management of neuropsychiatric disorders.AIM To examine the therapeutic efficacy of iTBS mode of rTMS for treating depressive symptoms in patients with AD.METHODS This retrospective study enrolled 105 individuals diagnosed with AD with depressive symptoms at Huzhou Third Municipal Hospital,affiliated with Huzhou University,between January 2020 and December 2023.Participants received standard pharmacological interventions and were categorized into control(n=53)and observation(n=52)groups based on treatment protocols.The observation group received iTBS mode of rTMS,while the control group received pseudo-stimulation.A comparative analysis evaluated psychological well-being,adverse events,and therapeutic at initiation of hospitalization(T0)and 15 days post-treatment(T1).RESULTS At T1,both groups exhibited a marked reduction in self-rating depression scale and Hamilton depression scale scores compared to T0.Furthermore,the observa-tion group showed a more pronounced decrease than the control group.By T1,the Mini-mental state examination scores for both groups had increased markedly from their initial T0 assessments.Importantly,the increase was particularly more substantial in the observation group than in the control group.Fourteen patients in the control group had ineffective treatment effects,while five patients in the observation group experienced the same.Additionally,the observation group experienced a substantially reduced incidence of ineffective treatment as compared to the control group(both P<0.05);there were no recorded serious adverse events in either group.CONCLUSION The iTBS model of rTMS effectively treated AD with depression,improving depressive symptoms and cognitive function in patients without serious adverse reactions,warranting clinical consideration.

Exosomes derived from microglia overexpressing miR-124-3p alleviate neuronal endoplasmic reticulum stress damage after repetitive mild traumatic brain injury

We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.

Analyzing the Combination Effects of Repetitive Transcranial Magnetic Stimulation and Motor Control Training on Balance Function and Gait in Patients with Stroke-Induced Hemiplegia

Objective:To analyze the effects of repetitive transcranial magnetic stimulation combined with motor control training on the treatment of stroke-induced hemiplegia,specifically focusing on the impact on patients’balance function and gait.Methods:Fifty-two cases of hemiplegic stroke patients were randomly divided into two groups,26 in the control group and 26 in the observation group,using computer-generated random grouping.All participants underwent conventional treatment and rehabilitation training.In addition to these,the control group received repetitive transcranial magnetic pseudo-stimulation therapy+motor control training,while the observation group received repetitive transcranial magnetic stimulation therapy+motor control training.The balance function and gait parameters of both groups were compared before and after the interventions and assessed the satisfaction of the interventions in both groups.Results:Before the invention,there were no significant differences in balance function scores and each gait parameter between the two groups(P>0.05).However,after the intervention,the observation group showed higher balance function scores compared to the control group(P<0.05).The observation group also exhibited higher step speed and step frequency,longer step length,and a higher overall satisfaction level with the intervention compared to the control group(P<0.05).Conclusion:The combination of repetitive transcranial magnetic stimulation and motor control training in the treatment of stroke-induced hemiplegia has demonstrated positive effects.It not only improves the patient’s balance function and gait but also contributes to overall physical rehabilitation.

Study on the Effect of Repetitive Peripheral Magnetic Stimulation Combined with Conventional Rehabilitation Measures on Shoulder Dysfunction in Early Stroke

Objective:To study the effect of repetitive peripheral magnetic stimulation(rPMS)combined with conventional rehabilitation measures on shoulder dysfunction in early stroke.Methods:60 patients with shoulder dysfunction in early stroke were selected,and all of them were admitted to our hospital from August 2021 to August 2023.The patients were randomly grouped into a control group(conventional rehabilitation measures intervention,30 cases)and an intervention group(rPMS and conventional rehabilitation measures intervention,30 cases)according to the lottery method.The pain scores,shoulder mobility,and motor function scores of the two groups were compared.Results:The pain score was lower in the intervention group,and the shoulder mobility and motor function scores were higher in the intervention group(P<0.05)as compared to that of the control group.Conclusion:The effect of combining rPMS and conventional rehabilitation measures in treating shoulder dysfunction in early stroke was remarkable and should be popularized.

Repetitive transcranial magnetic stimulation promotes neurological functional recovery in rats with traumatic brain injury by upregulating synaptic plasticity-related proteins

Studies have shown that repetitive transcra nial magnetic stimulation(rTMS)can enhance synaptic plasticity and improve neurological dysfunction.Howeve r,the mechanism through which rTMS can improve moderate traumatic brain injury remains poorly understood.In this study,we established rat models of moderate traumatic brain injury using Feeney's weight-dropping method and treated them using rTMS.To help determine the mechanism of action,we measured levels of seve ral impo rtant brain activity-related proteins and their mRNA.On the injured side of the brain,we found that rTMS increased the protein levels and mRNA expression of brain-derived neurotrophic factor,tropomyosin receptor kinase B,N-methyl-D-aspartic acid receptor 1,and phosphorylated cAMP response element binding protein,which are closely associated with the occurrence of long-term potentiation.rTMS also partially reve rsed the loss of synaptophysin after injury and promoted the remodeling of synaptic ultrastructure.These findings suggest that upregulation of synaptic plasticity-related protein expression is the mechanism through which rTMS promotes neurological function recovery after moderate traumatic brain injury.

Repetitive transcranial magnetic stimulation combined with olanzapine and amisulpride for treatment-refractory schizophrenia

BACKGROUND Treatment-refractory schizophrenia(TRS),accounting for approximately 30%of all schizophrenia cases,has poor treatment response and prognosis despite treatment with antipsychotic drugs.AIM To analyze the therapeutic effectiveness of repetitive transcranial magnetic stimulation(rTMS)combined with olanzapine(OLZ)and amisulpride(AMI)for TRS and its influence on the patient’s cognitive function.METHODS This study enrolled 114 TRS patients who received treatment at the First Affiliated Hospital of Zhengzhou University between July 2019 and July 2022.In addition to the basic OLZ+AMI therapy,54 cases of the control group(Con group)received modified electroconvulsive therapy,while 60 cases of the research group(Res group)received rTMS.Data on therapeutic effectiveness,safety(incidence of drowsiness,headache,nausea,vomiting,or memory impairment),Positive and Negative Symptom Scale,Montreal Cognitive Assessment Scale,and Schizophrenia Quality of Life Scale were collected from both cohorts for comparative analyses.RESULTS The Res group elicited a higher overall response rate and better safety profile when compared with the Con group.Additionally,a significant reduction was observed in the post-treatment Positive and Negative Symptom Scale and Schizophrenia Quality of Life Scale scores of the Res group,presenting lower scores than those of the Con group.Furthermore,a significant increase in the Montreal Cognitive Assessment Scale score was reported in the Res group,with higher scores than those of the Con group.CONCLUSION The treatment of TRS with rTMS and OLZ+AMI is effective and safe.Moreover,it can alleviate the patients’mental symptoms,improve their cognitive function and quality of life,and has a high clinical application value.

Quantitative proteomic and phosphoproteomic analyses of the hippocampus reveal the involvement of NMDAR1 signaling in repetitive mild traumatic brain injury

The cumulative damage caused by repetitive mild traumatic brain injury can cause long-term neurodegeneration leading to cognitive impairment.This cognitive impairment is thought to result specifically from damage to the hippocampus.In this study,we detected cognitive impairment in mice 6 weeks after repetitive mild traumatic brain injury using the novel object recognition test and the Morris water maze test.Immunofluorescence staining showed that p-tau expression was increased in the hippocampus after repetitive mild traumatic brain injury.Golgi staining showed a significant decrease in the total density of neuronal dendritic spines in the hippocampus,as well as in the density of mature dendritic spines.To investigate the specific molecular mechanisms underlying cognitive impairment due to hippocampal damage,we performed proteomic and phosphoproteomic analyses of the hippocampus with and without repetitive mild traumatic brain injury.The differentially expressed proteins were mainly enriched in inflammation,immunity,and coagulation,suggesting that non-neuronal cells are involved in the pathological changes that occur in the hippocampus in the chronic stage after repetitive mild traumatic brain injury.In contrast,differentially expressed phosphorylated proteins were mainly enriched in pathways related to neuronal function and structure,which is more consistent with neurodegeneration.We identified N-methyl-D-aspartate receptor 1 as a hub molecule involved in the response to repetitive mild traumatic brain injury,and western blotting showed that,while N-methyl-D-aspartate receptor 1 expression was not altered in the hippocampus after repetitive mild traumatic brain injury,its phosphorylation level was significantly increased,which is consistent with the omics results.Administration of GRP78608,an N-methyl-D-aspartate receptor 1 antagonist,to the hippocampus markedly improved repetitive mild traumatic brain injury-induced cognitive impairment.In conclusion,our findings suggest that N-methyl-D-aspartate receptor 1 signaling in the hippocampus is involved in cognitive impairment in the chronic stage after repetitive mild traumatic brain injury and may be a potential target for intervention and treatment.

The Effect of Different Rest Intervals on the Sustainability of Squat and Bench Press Repetitions in Karate Men

The purpose of this study was to compare the effect of three different rest intervals on the sustainability of squat and bench press on consecutive sets at 90% with 1RM （1 repetition maximum）-loads. Design and methods： Fifteen karate men were chosen to participate in this study （age of 22/3 ± 2/1 years; height 172/6 ± 3/6 cm; weight 67/8 ± 5/2 kg）. All subjects performed 7 sessions of squat ＆ bench press with 48 h intervals. At the first session, IRM was measured. During the rest 6 sessions, athletes performed 4 times squat ＆ bench press with 90% （IRM） at each session, one of three different rest intervals （60, 180, 225 seconds） were used randomly between sets. Number of repetitions performed ＆ repetition sustainability between different rest intervals were recorded. Results with Boneferoni method showed that each three different rest intervals caused decline in repetitions in squat ＆bench press. The repetition decline was significant in the bench press and squat. Repetition sustainability in 225 s in compare to 60 ＆ 180 s was more significant. Repetition sustainability also was higher in 180 s in compare to 60 s. On basis of findings from this study, we can recommend for best performance in bench press ＆ squat, rest intervals of 225 s, to maintain consecutive repetitions.

A Study of Repetitions in Harold Pinter’s The Dumb Waiter

Harold Pinter is one of the most influential modern British playwrights.Repetition is a frequent and noticeable phenome-non in his plays.In this paper,different kinds of repetition-the repetition of language,actions,silence and pause-in Pinter's TheDumb Waiter will be discussed to show both Ben and Gus'struggle for power and their useless efforts under the control of an dominant force.

A Fractional Order Fast Repetitive Control Paradigm of Vienna Rectifier for Power Quality Improvement

Due to attractive features,including high efficiency,low device stress,and ability to boost voltage,a Vienna rectifier is commonly employed as a battery charger in an electric vehicle(EV).However,the 6k±1 harmonics in the acside current of the Vienna rectifier deteriorate theTHDof the ac current,thus lowering the power factor.Therefore,the current closed-loop for suppressing 6k±1 harmonics is essential tomeet the desired total harmonic distortion(THD).Fast repetitive control(FRC)is generally adopted;however,the deviation of power grid frequency causes delay link in the six frequency fast repetitive control to become non-integer and the tracking performance to deteriorate.This paper presents the detailed parameter design and calculation of fractional order fast repetitive controller(FOFRC)for the non-integer delay link.The finite polynomial approximates the non-integer delay link through the Lagrange interpolation method.By comparing the frequency characteristics of traditional repetitive control,the effectiveness of the FOFRC strategy is verified.Finally,simulation and experiment validate the steadystate performance and harmonics suppression ability of FOFRC.

Development of miniaturized SAF-LIBS with high repetition rate acousto-optic gating for quantitative analysis

The self-absorption effect in laser-induced breakdown spectroscopy(LIBS)reduces the accuracy of quantitative measurement results.The self-absorption-free LIBS(SAF-LIBS)has been proved to directly capture the optically thin plasma spectra by setting an appropriate exposure time.In this work,a novel SAF-LIBS technique with high repetition rate acousto-optic gating is developed,in which an acousto-optic modulator is used as the shutter to diffract the optically thin fluorescence,and a high repetition rate laser is used to produce quasi-continuous plasmas to enhance the integral spectral intensity,so that the CCD spectrometer can replace an intensified CCD(ICCD)and echelle spectrometer in SAF-LIBS.Experimental results show that the average absolute prediction error of aluminum is reduced to 0.18%,which is equivalent to that of traditional SAF-LIBS.This technique not only effectively shields continuous background radiation and broadened spectral lines in optically thick plasma,but also has advantages of miniaturization,low cost,convenience and reliability.

磁刺激翳风穴联合针灸治疗面瘫的临床研究

目的 观察翳风穴体表重复磁刺激联合针灸治疗面瘫的临床疗效。方法 选取瑞金医院康复科门诊收治的80例首发中重度面瘫患者,分为治疗组和对照组,每组40例。治疗组给予翳风穴重复磁刺激联合针灸治疗,对照组则仅给予针灸治疗,观察其临床疗效。治疗前后选用肌电图及House-Brackmann(H-B)分级量表、Sunnybrook面部评分系统(SFGS)评价面神经功能恢复情况。结果 治疗组的治疗有效率为85.00%,明显优于对照组60.00%。干预后两组的面神经功能均较前改善(P<0.05),且治疗组的面神经功能及H-B、SFGS评分优于对照组(P<0.05)。结论 重复磁刺激翳风穴联合针灸是治疗中重度面瘫的一种安全有效的治疗方法,可加快面神经功能恢复,为进一步改善面瘫患者预后提供了新的治疗思路。

rTMS联合综合康复干预对孤独症谱系障碍患儿临床症状及语言功能康复的影响

目的探究重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)联合综合康复干预对孤独症谱系障碍(autism spectrum disorder,ASD)患儿临床症状及语言功能康复的影响。方法选取2021年8月~2023年5月在湖南省儿童医院康复中心接受治疗的141例ASD儿童,采用随机数表法分为观察组(72例)和对照组(69例)。对照组患儿给予常规综合康复治疗,观察组患儿在对照组基础上给予rTMS治疗,并对所有患儿进行5个月跟踪随访。对比相关参数及量表评分。结果治疗后,观察组孤独症行为量表(autism behavior checklist,ABC)和儿童孤独症评定量表(childhood autism rating s cale,CARS)评分均显著低于对照组(P<0.05),对比0~6岁小儿神经心理发育检查表得分,观察组治疗后适应能力、社交能力及语言功能得分均显著高于对照组(P<0.05),两组粗大动作、精细动作得分无显著差异(P>0.05)。末次随访时,观察组患儿的言语行为里程碑评估和安置计划(verbal behavior milestones assessment and placement program,VB-MAPP)得分显著高于对照组(P<0.05)。结论rTMS联合综合康复干预可显著改善ASD症状,提高患儿神经、语言、社交及感知等能力。

重复性项目前摄性调度优化方法研究

为应对重复性项目在建设过程中遇到的不确定性干扰,需对重复性项目进行前摄性调度优化研究,以增加项目进度计划容纳不确定性因素干扰的能力。本文首先分析基于线性计划法下,重复性项目中线状、条状、块状活动之间的时差关系,通过时差大小确定缓冲区间的选择范围。然后以工期、成本、鲁棒性为目标,构建多目标前摄性优化调度模型。并针对其NP-hard属性,设计改进粒子群优化算法:通过引入模拟退火算法,避免粒子群容易陷入局部最优的问题,算法测试表明改进算法具有较快的运算速度和较好的寻优能力。最后,通过一个重复性工程的案例,验证本文提出的前摄性调度优化模型的可行性和有效性;并通过仿真模拟发现,本文提出方法消耗更少缓冲就可以保证项目按时完工。通过研究分析得到以下结论:在编制进度计划时,可以通过在一定范围内增加资源量的方式,获得更优的进度计划。

用于并网逆变器的频率自适应复合重复控制

针对电网频率波动时重复控制(repeat control,RC)难以准确跟踪谐波分量和周期性干扰的问题,提出一种频率自适应复合重复控制策略(frequency adaptive PRC,FAPRC)。采用基于幂级数的滤波器实现分数延时。电网频率发生波动时,只需要输入频率比值的小数部分就能在基频和各次谐波频率处产生高增益,对实际电网频率进行准确跟踪,从而增强了系统在频率波动时的无静差跟踪能力和谐波抑制能力,实现频率自适应。在电网频率变化情况下对该控制策略进行仿真分析,与复合重复控制策略相比,所提策略更具优越性。