A novel refined dynamic model of high-speed maglev train-bridge coupled system for random vibration and running safety assessment

Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can be well characterized based on various stochastic excitations.A three-dimensional refined spatial random vibration analysis model of high-speed maglev train-bridge coupled system is established in this paper,in which multi-source uncertainty excitation can be considered simultaneously,and the probability density evolution method(PDEM)is adopted to reveal the system-specific uncertainty dynamic characteristic.The motion equation of the maglev vehicle model is composed of multi-rigid bodies with a total 210-degrees of freedom for each vehicle,and a refined electromagnetic force-air gap model is used to account for the interaction and coupling effect between the moving train and track beam bridges,which are directly established by using finite element method.The model is proven to be applicable by comparing with Monte Carlo simulation.By applying the proposed stochastic framework to the high maglev line,the random dynamic responses of maglev vehicles running on the bridges are studied for running safety and stability assessment.Moreover,the effects of track irregularity wavelength range under different amplitude and running speeds on the coupled system are investigated.The results show that the augmentation of train speed will move backward the sensitive wavelength interval,and track irregularity amplitude influences the response remarkably in the sensitive interval.

Enhancement of motor functional recovery in thoracic spinal cord injury: voluntary wheel running versus forced treadmill exercise

Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery and morphological changes following thoracic contusive spinal cord injury. After a 7-day recovery period after spinal cord injury, mice were assigned to either a trained group(10 weeks of voluntary running wheel or forced treadmill exercise) or an untrained group. Bi-weekly assessments revealed that the exercise-trained group, particularly the voluntary wheel exercise subgroup, displayed significantly improved locomotor recovery, more plasticity of dopaminergic and serotonin modulation compared with the untrained group. Additionally, exercise interventions led to gait pattern restoration and enhanced transcranial magnetic motor-evoked potentials. Despite consistent injury areas across groups, exercise training promoted terminal innervation of descending axons. In summary, voluntary wheel exercise shows promise for enhancing outcomes after thoracic contusive spinal cord injury, emphasizing the role of exercise modality in promoting recovery and morphological changes in spinal cord injuries. Our findings will influence future strategies for rehabilitation exercises, restoring functional movement after spinal cord injury.

The Effect of Body Pitching on Leg-Spring Behavior in Quadruped Running

In this paper we investigated how the running speed would affect the dynamics of body pitching, and whether body inertiais important for animals. Passive trotting of spring-mass model and passive bounding of spring-beam model were studied atdifferent speeds for different sets of body parameters respectively. Furthermore, different body inertias were used in bounding.We found that running speed exerts effect on leg performance by means of centrifugal force. The centrifugal force can be understoodas an enhancement to the natural frequency of the spring-mass system. The disadvantage of body pitching may beoffset by the great increase in centrifugal force at high speed. The results also reveal that body mass distribution might not be themain reason for the difference in maximal running speeds of different animals.

Metabolic cost of level,uphill,and downhill running in highly cushioned shoes with carbon-fiber plates

Background:Compared to conventional racing shoes,Nike Vaporfly 4% running shoes reduce the metabolic cost of level treadmill running by4%.The reduction is attributed to their lightweight,highly compliant,and resilient midsole foam and a midsole-embedded curved carbon-fiber plate.We investigated whether these shoes also could reduce the metabolic cost of moderate uphill(+3°) and downhill(-3°) grades.We tested the null hypothesis that,compared to conventional racing shoes,highly cushioned shoes with carbon-fiber plates would impart the same ~4%metabolic power(W/kg) savings during uphill and downhill running as they do during level running.Methods:After familiarization,16 competitive male runners performed six 5-min trials(2 shoes × 3 grades) in 2 Nike marathon racing-shoe models(Streak 6 and Vaporfly 4%) on a level,uphill(+3°),and downhill(-3°) treadmill at 13 km/h(3.61 m/s).We measured submaximal oxygen uptake and carbon dioxide production during Minutes 4-5 and calculated metabolic power(W/kg) for each shoe model and grade combination.Results:Compared to the conventional shoes(Streak 6),the metabolic power in the Vaporfly 4% shoes was 3.83%(level),2.82%(uphill),and2.70%(downhill)less(all p <0.001).The percent of change in metabolic power for uphill running was less compared to level running(p=0.04;effect size(ES)=0.561) but was not statistically different between downhill and level running(p=0.17;ES=0.356).Conclusion:On a running course with uphill and downhill sections,the metabolic savings and hence performance enhancement provided by Vaporfly 4% shoes would likely be slightly less overall,compared to the savings on a perfectly level race course.

Acute effect of foot strike patterns on in vivo tibiotalar and subtalar joint kinematics during barefoot running

Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics.However,technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns(RFS and FFS,respectively).This study uses a high-speed dual fluoroscopic imaging system(DFIS)to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics.Methods:Fifteen healthy male recreational runners underwent foot computed tomography scanning for the construction of 3-dimensional models.A high-speed DFIS(100 Hz)was used to collect 6 degrees of freedom kinematics for participants’tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition.Results:Compared with RFS,FFS exhibited greater internal rotation at 0%-20%of the stance phase in the tibiotalar joint.The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS(p<0.001,Cohen’s d=0.92).RFS showed more dorsiflexion at 0%-20%of the stance phase in the tibiotalar joint than FFS.RFS also presented a larger anterior translation(p<0.001,Cohen’s d=1.28)in the subtalar joint at i nitial contact than FFS.Conclusion:Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance.The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RF S and FFS during running.

Running Coupling Constants in N-N Interaction

The scalar and vector running coupling constants are derived using the renormalization group method in the σ-ω model. The numerical values of the two running coupling constants are obtained and the physical meaning of the result is discussed.

Analysis of the Diffractive Deep Inelastic Scattering Data with Running Coupling and Gluon Number Fluctuations

We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and gluon number fluctuations are included with x2/d.o.f. = 0.867, x2/d.o.f. = 0.923 and x2/d.o.f. = 0.878 for three different groups of experimental data. The values of diffusive coefficient subtracted from the fit are smaller than the ones obtained by considering only the gluon number fluctuations in our previous studies. The smaller values of the diffusive coefficient are in agreement with the theoretical predictions, where the gluon number fluctuations are suppressed by the running coupling which leads to smaller values of the diffusive coefficient.

Free running period affected by network structures of suprachiasmatic nucleus neurons exposed to constant light

Exposed to the natural light-dark cycle,24 h rhythms exist in behavioral and physiological processes of living beings.Interestingly,under constant darkness or constant light,living beings can maintain a robust endogenous rhythm with a free running period(FRP)close to 24 h.In mammals,the circadian rhythm is coordinated by a master clock located in the suprachiasmatic nucleus(SCN)of the brain,which is composed of about twenty thousand self-oscillating neurons.These SCN neurons form a heterogenous network to output a robust rhythm.Thus far,the exact network topology of the SCN neurons is unknown.In this article,we examine the effect of the SCN network structure on the FRP when exposed to constant light by a Poincare model.Four typical network structures are considered,including a nearest-neighbor coupled network,a Newman-Watts small world network,an Erd¨os-Renyi random network and a Barabasi-Albert(BA)scale free network.The results show that the FRP is longest in the BA network,because the BA network is characterized by the most heterogeneous structure among these four types of networks.These findings are not affected by the average node degree of the SCN network or the value of relaxation rate of the SCN neuronal oscillators.Our findings contribute to the understanding of how the network structure of the SCN neurons influences the FRP.

Stride length-velocity relationship during running with body weight support

Background： Lower body positive pressure （LBPP） treadmills can be used in rehabilitation programs and/or to supplement tun mileage in healthy runners by reducing the effective body weight and impact associated with running. The purpose of this study is to determine if body weight support influences the stride length （SL）-velocity as well as leg impact acceleration relationship during running. Methods： Subjects （n = 10, 21.4 ± 2.0 years, 72.4 ± 10.3 kg, 1.76 ± 0.09 m） completed 16 run conditions consisting of specific body weight support and velocity combinations. Velocities tested were 100%, 110%, 120%, and 130% of the preferred velocity （2.75± 0.36 m/s）. Body weight support conditions consisted of 0, 60%,5, 70%, and 80% body weight support. SL and leg impact accelerations were determined using a light-weight accelerometer mounted on the surface of the anterior-distal aspect of the tibia. A 4 × 4 （velocity x body weight support） repeated measures ANOVA was used for each dependent variable （a = 0.05）. Results： Neither SL nor leg impact acceleration were influenced by the interaction of body weight support and velocity （p 〉 0.05）. SL was least during no body weight support （p 〈 0.05） but not different between 60%, 70%, and 80% support （p 〉 0.05）. Leg impact acceleration was greatest during no body weight support （p 〈 0.05） but not different between 60%, 70%, and 80% support （p 〉 0.05）. SL and leg impact accelerations increased with velocity regardless of support （p 〈 0.05）. Conclusion： The relationships between SL and leg impact accelerations with velocity were not influenced by body weight support.

Novel and Self-Consistency Analysis of the QCD Running Coupling α_(s)(Q) in Both the Perturbative and Nonperturbative Domains

The quantum chromodynamics(QCD) coupling αs is the most important parameter for achieving precise QCD predictions. By using the well measured effective coupling α_(s)^(g)1)(Q) defined from the Bjorken sum rules as a basis, we suggest a novel self-consistency way to fix the αs at all scales: The QCD light-front holographic model is adopted for its infrared behavior, and the fixed-order p QCD prediction under the principle of maximum conformality(PMC) is used for its high-energy behavior. Using the PMC scheme-and-scale independent perturbative series,and by transforming it into the one under the physical V scheme, we observe that a precise αs running behavior in both the perturbative and nonperturbative domains with a smooth transition from small to large scales can be achieved.

Voluntary wheel running ameliorated the deleterious effects of high-fat diet on glucose metabolism,gut microbiota and microbial-associated metabolites

Exercise training is critical for the early prevention and treatment of obesity and diabetes mellitus.However,the mechanism with gut microbiota and fecal metabolites underlying the effects of voluntary wheel running on high-fat diet induced abnormal glucose metabolism has not been fully elaborated.C57BL/6 male mice were randomly assigned to 4 groups according to diets(fed with normal chow diet or high-fat diet)and running paradigm(housed in static cage or with voluntary running wheel).An integrative 16S rDNA sequencing and metabolites profiling was synchronously performed to characterize the effects of voluntary wheel running on gut microbiota and metabolites.It showed that voluntary wheel running prevented the detrimental effects of high-fat feeding on glucose metabolism 16S rDNA sequencing showed remarkable changes in Rikenella and Marvinbryantia genera.Metabolic profiling indicated multiple altered metabolites,which were enriched in secondary bile acid biosynthesis signaling.In conclusion,our study indicated that voluntary wheel running significantly improved glucose metabolism and counteracted the deleterious effects of high-fat feeding on body weight and glucose intolerance.We further found that voluntary wheel running could integratively program gut microbiota composition and fecal metabolites changes,and may regulate muricholic acid metabolism and secondary bile acid biosynthesis in high-fat fed mice.

Influence of pier height on the safety of trains running on high-speed railway bridges during earthquakes

Sudden earthquakes pose a threat to the running safety of trains on high-speed railway bridges,and the stiffness of piers is one of the factors affecting the dynamic response of train-track-bridge system.In this paper,a experiment of a train running on a high-speed railway bridge is performed based on a dynamic experiment system,and the corresponding numerical model is established.The reliability of the numerical model is verified by experiments.Then,the experiment and numerical data are analyzed to reveal the pier height effects on the running safety of trains on bridges.The results show that when the pier height changes,the frequency of the bridge below the 30 m pier height changes greater;the increase of pier height causes the transverse fundamental frequency of the bridge close to that of the train,and the shaking angle and lateral displacement of the train are the largest for bridge with 50 m pier,which increases the risk of derailment;with the pier height increases from 8 m to 50 m,the derailment coefficient obtained by numerical simulations increases by 75% on average,and the spectral intensity obtained by experiments increases by 120% on average,two indicators exhibit logarithmic variation.

Running safety assessment method of trains under seismic conditions based on the derailment risk domain

The accurate assessment of running safety during earthquakes is of significant importance for ensuring the safety of railway lines.Currently,assessment methods based on a single index suffer from issues such as misjudgment of operational safety and difficulty in evaluating operational margin,making them unsuitable for assessing train safety during earthquakes.Therefore,in order to propose an effective evaluation method for the running safety of trains during earthquakes,this study employs three indexes,namely lateral displacement of the wheel–rail contact point,wheel unloading rate,and wheel lift,to describe the lateral and vertical contact states between the wheel and rail.The corresponding evolution characteristics of the wheel–rail contact states are determined,and the derailment forms under different frequency components of seismic motion are identified through dynamic numerical simulations of the train–track coupled system under sine excitation.The variations in the wheel–rail contact states during the transition from a safe state to the critical state of derailment are analyzed,thereby constructing the evolutionary path of train derailment and seismic derailment risk domain.Lastly,the wheel–rail contact and derailment states under seismic conditions are analyzed,thus verifying the effectiveness of the evaluation method for assessing running safety under earthquakes proposed in this study.The results indicate that the assessment method based on the derailment risk domain accurately and comprehensively reflects the wheel–rail contact states under seismic conditions.It successfully determines the forms of train derailment,the risk levels of derailment,and the evolutionary paths of derailment risk.

SmartMicro Grid Energy System Management Based on Optimum Running Cost for Rural Communities in Rwanda

The governmental electric utility and the private sector are joining hands to meet the target of electrifying all households by 2024.However,the aforementioned goal is challenged by households that are scattered in remote areas.So far,Solar Home Systems(SHS)have mostly been applied to increase electricity access in rural areas.SHSs have continuous constraints to meet electricity demands and cannot run income-generating activities.The current research presents the feasibility study of electrifying Remera village with the smart microgrid as a case study.The renewable energy resources available in Remera are the key sources of electricity in that village.The generation capacity is estimated based on the load profile.The microgrid configurations are simulated with HOMER,and the genetic algorithm is used to analyze the optimum cost.By analyzing the impact of operation and maintenance costs,the results show that the absence of subsidies increases the levelized cost of electricity(COE)five times greater than the electricity price from the public utility.The microgrid made up of PV,diesel generator,and batteries proved to be the most viable solution and ensured continuous power supply to customers.By considering the subsidies,COE reaches 0.186$/kWh,a competitive price with electricity from public utilities in Rwanda.

Safety of the express freight train running over a long-span bridge

Purpose-Express freight transportation is in rapid development currently.Owing to the higher speed of express freight train,the deformation of the bridge deck worsens the railway line condition under the action of wind and train moving load when the train runs over a long-span bridge.Besides,the blunt car body of vehicle has poor aerodynamic characteristics,bringing a greater challenge on the running stability in the crosswind.Design/methodology/approach-In this study,the aerodynamic force coefficients of express freight vehicles on the bridge are measured by scale model wind tunnel test.The dynamic model of the train-long-span steel truss bridge coupling system is established,and the dynamic response as well as the running safety of vehicle are evaluated.Findings-The results show that wind speed has a significant influence on running safety,which is mainly reflected in the over-limitation of wheel unloading rate.The wind speed limit decreases with train speed,and it reduces to 18.83 m/s when the train speed is 160 km/h.Originality/value-This study deepens the theoretical understanding of the interaction between vehicles and bridges and proposes new methods for analyzing similar engineering problems.It also provides a new theoretical basis for the safety assessment of express freight trains.

Review of Research on English Translation of Chinese Running Sentences

In order to convey complete meanings,there is a phenomenon in Chinese of using multiple running sentences.Xu Jingning(2023,p.66)states,“In communication,a complete expression of meaning often requires more than one clause,which is common in human languages.”Domestic research on running sentences includes discussions on defining the concept and structural features of running sentences,sentence properties,sentence pattern classifications and their criteria,as well as issues related to translating running sentences into English.This article primarily focuses on scholarly research into the English translation of running sentences in China,highlighting recent achievements and identifying existing issues in the study of running sentence translation.However,by reviewing literature on the translation of running sentences,it is found that current research in the academic community on non-core running sentences is limited.Therefore,this paper proposes relevant strategies to address this issue.

Tactical planning and optimization of a milk run system of parts pickup for an engine manufacturer

A real-life milk run system designing problem of an engine manufacturer adopted JIT(just-in-time)production is studied.In the process of milk run system planning and design,the supply base is identified and a supplier site map is plotted for an arrangement of routes on which parts are periodically collected in a JIT manner from many scattered suppliers.With unit load designing,vehicle choosing and fleet sizing,pickup routing,vehicle assigning and scheduling problems are studied.Among these problems,a CVRP problem is identified and formulated as the key optimization in designing this milk run system,and it is solved through an optimization process.This tactical planning and optimization process gives a good solution to the real problem,and may shed light on the planning of similar systems.

韩国综艺节目《Running man》的跨文化传播特色及启示

《Running man》是韩国SBS电视台于2010年7月11日开播的全新游戏类综艺节目,节目播出已有3年。新颖的节目形式、趣味的游戏内容以及主持人的精彩演出等因素使得节目收视率节节攀升,不仅在韩国备受瞩目,而且在亚洲集聚了不少人气。本文拟探讨作为载体的《Running man》是如何传播韩国文化的,在传播的过程中又形成了哪些特色,让受众尤其是海外国家的受众乐于接受这种不同文化,以期对我国综艺节目甚至文化传播活动带来一些启发。

简析《奔跑吧,兄弟》和《Running Man》的异同

近来，国内娱乐节目引进与模仿的方向从欧美转向了韩国。湖南卫视的《我是歌手》、《爸爸去哪儿》，四川卫视的《两天一夜》，浙江卫视的《奔跑吧，兄弟》，都是从韩国引进的节目。中韩两国文化的亲缘性和地理位置的接近性，使得引进自韩国的节目更适合本土化生存。《奔跑吧，兄弟》的播出，标志着国内电视节目版权引进模式从单纯地购买版权进入了“联合开发”的新时期。《奔跑吧，兄弟》和《Running Man》的异同之处显示出了当今优秀娱乐节目的走向。

电视真人秀节目《Running Man》的叙事策略

本文以《奔跑吧兄弟》的母版节目——《Running Man》作为研究对象,从人物、情节和游戏三个篇章对其叙事上的技巧和策略进行分析。登峰造极的无主角叙事策略、别开生面的情节化叙事和形神俱佳的游戏都是其叙事魅力的来源,也是值得我国同类节目参考和学习的诀窍所在。