This work investigates a multi-product parallel disassembly line balancing problem considering multi-skilled workers.A mathematical model for the parallel disassembly line is established to achieve maximized disassemb...This work investigates a multi-product parallel disassembly line balancing problem considering multi-skilled workers.A mathematical model for the parallel disassembly line is established to achieve maximized disassembly profit and minimized workstation cycle time.Based on a product’s AND/OR graph,matrices for task-skill,worker-skill,precedence relationships,and disassembly correlations are developed.A multi-objective discrete chemical reaction optimization algorithm is designed.To enhance solution diversity,improvements are made to four reactions:decomposition,synthesis,intermolecular ineffective collision,and wall invalid collision reaction,completing the evolution of molecular individuals.The established model and improved algorithm are applied to ball pen,flashlight,washing machine,and radio combinations,respectively.Introducing a Collaborative Resource Allocation(CRA)strategy based on a Decomposition-Based Multi-Objective Evolutionary Algorithm,the experimental results are compared with four classical algorithms:MOEA/D,MOEAD-CRA,Non-dominated Sorting Genetic Algorithm Ⅱ(NSGA-Ⅱ),and Non-dominated Sorting Genetic Algorithm Ⅲ(NSGA-Ⅲ).This validates the feasibility and superiority of the proposed algorithm in parallel disassembly production lines.展开更多
The human scalp harbors a diverse range of microbiome,much like other skin surfaces,where both beneficial and harmful microorganisms coexist.This study explores the possibility of balancing key scalp microorganisms,pa...The human scalp harbors a diverse range of microbiome,much like other skin surfaces,where both beneficial and harmful microorganisms coexist.This study explores the possibility of balancing key scalp microorganisms,particularly Staphylococcus epidermidis,Staphylococcus aureus and Malassezia species.While Staphylococcus epidermidis plays a beneficial role in maintaining scalp health by producing antimicrobial proteins and supporting the skin barrier,Staphylococcus aureus is identified as a pathogen linked to skin infections and dandruff formation.Malassezia fungi degrade triglycerides in sebum into unsaturated fatty acids,exacerbating scalp conditions like dandruff.In order to promote the beneficial microbe while inhibit the harmful ones,we investigated the combination of 1.0 mM pyrrolidone carboxylate-zinc(PCA-Zn),0.2%malt oligosaccharides(MT:corn-derived oligosaccharide mainly containing maltotetraose)and 0.05 mM Hinokitiol on its microbial activity,which significantly enhanced the growth of Staphylococcus epidermidis while inhibiting both Staphylococcus aureus and Malassezia,offering insights into promising strategies for scalp care.展开更多
With the continuous expansion of the data center network scale, changing network requirements, and increasing pressure on network bandwidth, the traditional network architecture can no longer meet people’s needs. The...With the continuous expansion of the data center network scale, changing network requirements, and increasing pressure on network bandwidth, the traditional network architecture can no longer meet people’s needs. The development of software defined networks has brought new opportunities and challenges to future networks. The data and control separation characteristics of SDN improve the performance of the entire network. Researchers have integrated SDN architecture into data centers to improve network resource utilization and performance. This paper first introduces the basic concepts of SDN and data center networks. Then it discusses SDN-based load balancing mechanisms for data centers from different perspectives. Finally, it summarizes and looks forward to the study on SDN-based load balancing mechanisms and its development trend.展开更多
Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have ...Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging population.Posture and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous mechanisms.To effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory signals.The mechanisms which underpin the integration of these multisensory signals are the principal topic of the present work.Existing multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older adults.Insufficient emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and balance.In the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s disease.We also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older adults.Lastly,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.展开更多
BACKGROUND Liver transplantation aims to increase the survival of patients with end-stage liver diseases and improve their quality of life.The number of organs available for transplantation is lower than the demand.To...BACKGROUND Liver transplantation aims to increase the survival of patients with end-stage liver diseases and improve their quality of life.The number of organs available for transplantation is lower than the demand.To provide fair organ distribution,predictive mortality scores have been developed.AIM To compare the Acute Physiology and Chronic Health Evaluation IV(APACHE IV),balance of risk(BAR),and model for end-stage liver disease(MELD)scores as predictors of mortality.METHODS Retrospective cohort study,which included 283 adult patients in the postoperative period of deceased donor liver transplantation from 2014 to 2018.RESULTS The transplant recipients were mainly male,with a mean age of 58.1 years.Donors were mostly male,with a mean age of 41.6 years.The median cold ischemia time was 3.1 hours,and the median intensive care unit stay was 5 days.For APACHE IV,a mean of 59.6 was found,BAR 10.7,and MELD 24.2.The 28-day mortality rate was 9.5%,and at 90 days,it was 3.5%.The 28-day mortality prediction for APACHE IV was very good[area under the curve(AUC):0.85,P<0.001,95%CI:0.76-0.94],P<0.001,BAR(AUC:0.70,P<0.001,95%CI:0.58–0.81),and MELD(AUC:0.66,P<0.006,95%CI:0.55-0.78),P<0.008.At 90 days,the data for APACHE IV were very good(AUC:0.80,P<0.001,95%CI:0.71–0.90)and moderate for BAR and MELD,respectively,(AUC:0.66,P<0.004,95%CI:0.55–0.77),(AUC:0.62,P<0.026,95%CI:0.51–0.72).All showed good discrimination between deaths and survivors.As for the best value for liver transplantation,it was significant only for APACHE IV(P<0.001).CONCLUSION The APACHE IV assessment score was more accurate than BAR and MELD in predicting mortality in deceased donor liver transplant recipients.展开更多
The Brief Interactive Optimism Scale (BIOS-G), recently published, was developed to measure optimism based on the interactive personality styles theory in the general population of Mexican adults. It has been validate...The Brief Interactive Optimism Scale (BIOS-G), recently published, was developed to measure optimism based on the interactive personality styles theory in the general population of Mexican adults. It has been validated in both the general population in Mexico and other Latin American countries. This study aims to further consolidate the validity of the BIOS-G in a specific population. The objectives are to assess the psychometric properties of its items, validate its unidimensional structure, describe its distribution, verify its internal consistency, and examine its direct relationship with affective balance and positive affect, as well as its inverse relationship with emotional exhaustion and negative affect among Mexican university teachers. The BIOS-G, the CESQT emotional exhaustion subscale, and Scale of Positive and Negative Experience (SPANE) were administered to a non-probability sample of 213 Mexican university teachers. All items demonstrated discriminative power and internal consistency. The scale showed internal consistency (Green-Yang ordinal ω = 0.74 and McDonald ordinal ω = 0.88). The one-factor model presented good to acceptable fit to the data, with an average variance extracted of 0.65. Its distribution was negatively skewed and mesokurtic. The BIOS-G correlated directly with SPANE’s affective balance and positive emotional experiences and inversely with negative emotional experiences and emotional exhaustion, with moderate strengths of association. Its mean score was higher in men than in women and correlated positively with age. It is concluded that the BIOS-G demonstrates internal consistency and validity evidence among Mexican university teachers, and its use in this specific population is recommended.展开更多
Organic material combined with inorganic fertilizer has been shown to greatly improve crop yield and maintain soil fertility globally. However, it remains unclear if crop yield and soil fertility can be sustained in t...Organic material combined with inorganic fertilizer has been shown to greatly improve crop yield and maintain soil fertility globally. However, it remains unclear if crop yield and soil fertility can be sustained in the long term under the combined application of organic and inorganic fertilizers. Three long-term field trials were conducted to investigate the effects of organic amendments on the grain sustainable yield index(SYI), soil fertility index(SFI)and nutrient balance in maize–wheat cropping systems of central and southern China during 1991–2019. Five treatments were included in the trials: 1) no fertilization(control);2) balanced mineral fertilization(NPK);3) NPK plus manure(NPKM);4) high dose of NPK plus manure(1.5NPKM);and 5) NPK plus crop straw(NPKS). Over time, the grain yields of wheat and maize showed an increasing trend in all four fertilization treatments at the Yangling(YL) and Zhengzhou(ZZ) locations, while they declined at Qiyang(QY). The grain yield in the NPKM and 1.5NPKM treatments gradually exceeded that of the NPK and NPKS treatments at the QY site. The largest SYI was recorded in the NPKM treatment across the three sites, suggesting that inorganic fertilizer combined with manure can effectively improve crop yield sustainability. Higher SYI values were recorded at the YL and ZZ sites than at the QY site, possibly because the soil was more acid at QY. The key factors affecting grain yield were soil available phosphorus(AP) and available potassium(AK) at the YL and ZZ sites, and pH and AP at the QY site.All fertilization treatments resulted in soil N and P surpluses at the three sites, but soil K surpluses were recorded only at the QY site. The SFI was greater in the 1.5NPKM, NPKM and NPKS treatments than in the NPK treatment by 13.3–40.0 and 16.4–63.6% at the YL and ZZ sites, respectively, and was significantly higher in the NPKM and 1.5NPKM treatments than in the NPK and NPKS treatments at the QY site. A significant, positive linear relationship was found between SFI and crop yield, and SYI and nutrient balance, indicating that grain yield and its sustainability significantly increased with increasing soil fertility. The apparent N, P and K balances positively affected SFI.This study suggests that the appropriate amount of manure mixed with mineral NPK fertilizer is beneficial to the development of sustainable agriculture, which effectively increases the crop yield and yield sustainability by improving soil fertility.展开更多
Objective: To investigate the effect of a self-developed balance rhythm dance program on the rehabilitation of motor function and the reduction of fall risk in elderly women with diminished balance function. Methods: ...Objective: To investigate the effect of a self-developed balance rhythm dance program on the rehabilitation of motor function and the reduction of fall risk in elderly women with diminished balance function. Methods: Fifty elderly women with reduced balance function, admitted to the Qingbar Elderly Care Center of Chongqing Medical University from December 2022 to December 2023, were randomly selected and divided into two groups. The aerobic exercise group (25 patients) received traditional treatment and rehabilitation nursing, while the balance rhythm dance intervention group (25 patients) received the balance rhythm dance intervention in addition to traditional treatment and rehabilitation nursing. The Unified Parkinson’s Disease Rating Scale (UPDRS) and Berg Balance Scale (BBS) were used as evaluation indicators to compare the intervention effects between the two groups. Results: The data revealed that the balance rhythm dance intervention significantly improved the motor ability and balance function of elderly women in the intervention group (P < 0.01), with statistically significant differences observed. Conclusion: The balance rhythm dance program plays a critical role in promoting the rehabilitation of motor function and balance ability in elderly women, effectively enhancing their quality of life.展开更多
Xiong'an New Area boasts abundant geothermal resources,with widespread Jixianian geother-mal reservoirs serving as key targets for exploration and development.Zoning geothermal resources helps characterize their d...Xiong'an New Area boasts abundant geothermal resources,with widespread Jixianian geother-mal reservoirs serving as key targets for exploration and development.Zoning geothermal resources helps characterize their distribution and attributes,offering critical guidance for their sustainable exploitation and utilization.This study integrates data from drilling and production tests across 21 geothermal wells to analyze the Jixianian strata,including depth,thickness,temperature,single-well water yield,Groundwater Level Depth(GWD),and Total Dissolved Solids(TDS).Employing fuzzy mathematics,a zoning analysis was performed,yielding quantitative evaluation scores and delineating favorable zones for development.Key findings include:(1)Geothermal reservoirs in the Rongcheng and Niutuozhen uplifts exhibit shallow burial depths,substantial thicknesses,high productivity,and relatively low temperatures,making them highly suitable for large-scale geothermal exploitation;(2)Zones with high resource potential but uncertain conditions require further exploration to mitigate development risks;(3)Areas near the Rongcheng fault or Jixianian strata buried deeper than 4,000 m are recommended for deferred exploitation;(4)Comprehensive evaluation reveals that the Jixianian carbonate geothermal reservoirs in Xiong'an New Area manifest 168 geothermal resources of 5,370.31×10 J,geothermal fluid reserves of 101.17×10 m3,and recoverable fluid 4 reserves of 93.41×10 m3/d under balanced extraction and reinjection.Recoverable geothermal heat 164 amounts to 9.36×10 J/a,equivalent to 319.4×10 t/a of standard coal.This study provides valuable insights into the exploration and sustainable exploitation of deep geothermal reservoirs in Xiong'an New Area,enhancing resource utilization and contributing to the development of a green and sustainable Xiong'an New Area.展开更多
Oxidation of self-stored carbohydrates and lipids provides the energy for the rapid morphogenetic transformation during asexual and infection-related development in Pyricularia oryzae,which results in intracellular ac...Oxidation of self-stored carbohydrates and lipids provides the energy for the rapid morphogenetic transformation during asexual and infection-related development in Pyricularia oryzae,which results in intracellular accumulation of reducing equivalents NADH and FADH_(2),requiring a cytosolic shuttling machinery towards mitochondria.Our previous studies identified the mitochondrial D-lactate dehydrogenase MoDld1 as a regulator to channel the metabolite flow in conjunction with redox homeostasis.However,the regulator(s)facilitating the cytosolic redox balance and the importance in propelling nutrient metabolite flow remain unknown.The G-3-P shuttle is a conserved machinery transporting the cytosolic reducing power to mitochondria.In P.oryzae,the mitochondrial G-3-P dehydrogenase Gpd2 was required for cellular NAD^(+)/NADH balance and fungal virulence.In this study,we relocate the mitochondrial G-3-P dehydrogenase Gpd2 to the cytosol for disturbing cytosolic redox status.Our results showed overexpression of cytosolic gpd2^(Δmts)without the mitochondrial targeted signal(MTS)driven by Ribosomal protein 27 promoter(PR27)exerted conflicting regulation of cellular oxidoreductase activities compared to theΔModld1 deletion mutant by RNA-seq and prevented the conidiation and pathogenicity of P.oryzae.Moreover,overexpression of gpd2^(Δmts)caused defects in glycogen and lipid mobilization underlying asexual and infectious structural development associated with decreased cellular NADH production and weakened anti-oxidation activities.RNA-seq and non-targeted metabolic profiling revealed down-regulated transcriptional activities of carbohydrate metabolism and lower abundance of fatty acids and secondary metabolites in RP27:gpd2^(Δmts).Thus,our studies indicate the essential role of cytosolic redox control in nutrient metabolism fueling the asexual and infection-related development in P.oryzae.展开更多
In this paper, an identification method to estimate the unbalances is introduced, which is based on the boundary element method (BEM). By using the vibration response measured at some points on the flexible rotor the ...In this paper, an identification method to estimate the unbalances is introduced, which is based on the boundary element method (BEM). By using the vibration response measured at some points on the flexible rotor the unbalances can be identified conveniently. Therefore, the rotor can be balanced without test runs.展开更多
The Internet of Vehicles(IoV)has been widely researched in recent years,and cloud computing has been one of the key technologies in the IoV.Although cloud computing provides high performance compute,storage and networ...The Internet of Vehicles(IoV)has been widely researched in recent years,and cloud computing has been one of the key technologies in the IoV.Although cloud computing provides high performance compute,storage and networking services,the IoV still suffers with high processing latency,less mobility support and location awareness.In this paper,we integrate fog computing and software defined networking(SDN) to address those problems.Fog computing extends computing and storing to the edge of the network,which could decrease latency remarkably in addition to enable mobility support and location awareness.Meanwhile,SDN provides flexible centralized control and global knowledge to the network.In order to apply the software defined cloud/fog networking(SDCFN) architecture in the IoV effectively,we propose a novel SDN-based modified constrained optimization particle swarm optimization(MPSO-CO) algorithm which uses the reverse of the flight of mutation particles and linear decrease inertia weight to enhance the performance of constrained optimization particle swarm optimization(PSO-CO).The simulation results indicate that the SDN-based MPSO-CO algorithm could effectively decrease the latency and improve the quality of service(QoS) in the SDCFN architecture.展开更多
Imbalance vibration is a typical failure mode of rotational machines and has significant negative effects on the efficiency,accuracy,and service life of equipment.To automatically reduce the imbalance vibration during...Imbalance vibration is a typical failure mode of rotational machines and has significant negative effects on the efficiency,accuracy,and service life of equipment.To automatically reduce the imbalance vibration during the operational process,different types of active balancing actuators have been designed and widely applied in actual production.However,the existing electromagnetic-ring active balancing actuator is designed based on an axial excitation structure which can cause structural instability and has low electromagnetic driving efficiency.In this paper,a novel radial excitation structure and the working principle of an electromagnetic-ring active balancing actuator with a combined driving strategy are presented in detail.Then,based on a finite element model,the performance parameters of the actuator are analyzed,and reasonable design parameters are obtained.Self-locking torque measurements and comparative static and dynamic experiments are performed to validate the self-locking torque and driving efficiency of the actuator.The results indicate that this novel active balancing actuator has sufficient self-locking torque,achieves normal step rotation at 2000 r/min,and reduces the driving voltage by 12.5%.The proposed novel balancing actuator using radial excitation and a combination of permanent magnets and soft-iron blocks has improved electromagnetic efficiency and a more stable and compact structure.展开更多
In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. T...In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. The objective of this work aims in reducing the number of workstations, work load index between stations and within each station. As manual contribution of workers in final assembly line is more, ergonomics is taken as an additional objective function. Ergonomic risk level of a workstation is evaluated using a parameter called accumulated risk posture(ARP), which is calculated using rapid upper limb assessment(RULA) check sheet. This work is based on the case study of an MMAL problem in Rane(Madras) Ltd.(India), in which a problem based genetic algorithm(GA) has been proposed to minimize the mentioned objectives. The working of the genetic operators such as selection, crossover and mutation has been modified with respect to the addressed MMAL problem. The results show that there is a significant impact over productivity and the process time of the final assembled product, i.e., the rate of production is increased by 39.5% and the assembly time for one particular model is reduced to 13 min from existing 18 min. Also, the space required using the proposed assembly line is only 200 m2 against existing 350 m2. Further, the algorithm helps in reducing workers fatigue(i.e., ergonomic friendly).展开更多
High level architecture(HLA) is the open standard in the collaborative simulation field. Scholars have been paying close attention to theoretical research on and engineering applications of collaborative simulation ba...High level architecture(HLA) is the open standard in the collaborative simulation field. Scholars have been paying close attention to theoretical research on and engineering applications of collaborative simulation based on HLA/RTI, which extends HLA in various aspects like functionality and efficiency. However, related study on the load balancing problem of HLA collaborative simulation is insufficient. Without load balancing, collaborative simulation under HLA/RTI may encounter performance reduction or even fatal errors. In this paper, load balancing is further divided into static problems and dynamic problems. A multi-objective model is established and the randomness of model parameters is taken into consideration for static load balancing, which makes the model more credible. The Monte Carlo based optimization algorithm(MCOA) is excogitated to gain static load balance. For dynamic load balancing, a new type of dynamic load balancing problem is put forward with regards to the variable-structured collaborative simulation under HLA/RTI. In order to minimize the influence against the running collaborative simulation, the ordinal optimization based algorithm(OOA) is devised to shorten the optimization time. Furthermore, the two algorithms are adopted in simulation experiments of different scenarios, which demonstrate their effectiveness and efficiency. An engineering experiment about collaborative simulation under HLA/RTI of high speed electricity multiple units(EMU) is also conducted to indentify credibility of the proposed models and supportive utility of MCOA and OOA to practical engineering systems. The proposed research ensures compatibility of traditional HLA, enhances the ability for assigning simulation loads onto computing units both statically and dynamically, improves the performance of collaborative simulation system and makes full use of the hardware resources.展开更多
Measurement error of unbalance＇s vibration response plays a crucial role in calibration and on-line updating of influence coefficient（IC）. Focusing on the two problems that the moment estimator of data used in cali...Measurement error of unbalance＇s vibration response plays a crucial role in calibration and on-line updating of influence coefficient（IC）. Focusing on the two problems that the moment estimator of data used in calibration process cannot fulfill the accuracy requirement under small sample and the disturbance of measurement error cannot be effectively suppressed in updating process, an IC calibration and on-line updating method based on hierarchical Bayesian method for automatic dynamic balancing machine was proposed. During calibration process, for the repeatedly-measured data obtained from experiments with different trial weights, according to the fact that measurement error of each sensor had the same statistical characteristics, the joint posterior distribution model for the true values of the vibration response under all trial weights and measurement error was established. During the updating process, information obtained from calibration was regarded as prior information, which was utilized to update the posterior distribution of IC combined with the real-time reference information to implement online updating. Moreover, Gibbs sampling method of Markov Chain Monte Carlo（MCMC） was adopted to obtain the maximum posterior estimation of parameters to be estimated. On the independent developed dynamic balancing testbed, prediction was carried out for multiple groups of data through the proposed method and the traditional method respectively, the result indicated that estimator of influence coefficient obtained through the proposed method had higher accuracy; the proposed updating method more effectively guaranteed the measurement accuracy during the whole producing process, and meantime more reasonably compromised between the sensitivity of IC change and suppression of randomness of vibration response.展开更多
In order to balancing based on data achieve dynamic load flow level, in this paper, we apply SDN technology to the cloud data center, and propose a dynamic load balancing method of cloud center based on SDN. The appro...In order to balancing based on data achieve dynamic load flow level, in this paper, we apply SDN technology to the cloud data center, and propose a dynamic load balancing method of cloud center based on SDN. The approach of using the SDN technology in the current task scheduling flexibility, accomplish real-time monitoring of the service node flow and load condition by the OpenFlow protocol. When the load of system is imbalanced, the controller can allocate globally network resources. What＇s more, by using dynamic correction, the load of the system is not obvious tilt in the long run. The results of simulation show that this approach can realize and ensure that the load will not tilt over a long period of time, and improve the system throughput.展开更多
In Software-Dened Networks(SDN),the divergence of the control interface from the data plane provides a unique platform to develop a programmable and exible network.A single controller,due to heavy load trafc triggered...In Software-Dened Networks(SDN),the divergence of the control interface from the data plane provides a unique platform to develop a programmable and exible network.A single controller,due to heavy load trafc triggered by different intelligent devices can not handle due to it’s restricted capability.To manage this,it is necessary to implement multiple controllers on the control plane to achieve quality network performance and robustness.The ow of data through the multiple controllers also varies,resulting in an unequal distribution of load between different controllers.One major drawback of the multiple controllers is their constant conguration of the mapping of the switch-controller,quickly allowing unequal distribution of load between controllers.To overcome this drawback,Software-Dened Vehicular Networking(SDVN)has evolved as a congurable and scalable network,that has quickly achieved attraction in wireless communications from research groups,businesses,and industries administration.In this paper,we have proposed a load balancing algorithm based on latency for multiple SDN controllers.It acknowledges the evolving characteristics of real-time latency vs.controller loads.By choosing the required latency and resolving multiple overloads simultaneously,our proposed algorithm solves the loadbalancing problems with multiple overloaded controllers in the SDN control plane.In addition to the migration,our algorithm has improved 25%latency as compared to the existing algorithms.展开更多
An active balancing technology has been applied to solve the severe vibration caused by sudden unbalance in rotating machineries during their working process. First, based on the generation principle of sudden unbalan...An active balancing technology has been applied to solve the severe vibration caused by sudden unbalance in rotating machineries during their working process. First, based on the generation principle of sudden unbalance, a simulation test stand with a sudden unbalance generation device was set up. Then, the balancing planes were optimized by using the finite element method （FEM） to determine the position for balancing device installation. Finally, the active balancing experiments were carried out on the test stand. The experimental results indicate that the vibration response caused by sudden unbalance can be decreased from 77μm to 8μm by using the active balancing device, and the vibration amplitude reduction was up to 89.6%. From this example, it can be concluded that the active balancing device, which is installed on a proper position of the rotor, can effectively control the random transient synchronous vibration, demonstrating its high value in engineering practice.展开更多
Mass imbalance-induced vibration affects the rotating machinery very large,especially the highspeed types.Off-line balancing techniques have been widely developed for rejecting unbalance-induced vibration but do not e...Mass imbalance-induced vibration affects the rotating machinery very large,especially the highspeed types.Off-line balancing techniques have been widely developed for rejecting unbalance-induced vibration but do not eliminate unbalanced vibration in the working state.Moreover,multiple start-stops are required in off-line balancing techniques.Therefore,research on an efficient electromagnetically-driven auto-balancer is carried out in the present work,and an internal excitation actuator is designed in this balancer.The electromagnetic characteristics of the two copper coil bobbins in the internal excitation actuator are compared and analyzed.The permanent magnets inside the actuator are simulated and analyzed with different sections of round,rectangular,and elliptical.And the results show that the elliptic type has the largest self-locking force.Finally,the dynamic balance test is performed on a test bench equipped with a designed electromagnetic balancing actuator,and the unbalance vibration is reduced from 130.23 μm to 5.98 μm.展开更多
文摘This work investigates a multi-product parallel disassembly line balancing problem considering multi-skilled workers.A mathematical model for the parallel disassembly line is established to achieve maximized disassembly profit and minimized workstation cycle time.Based on a product’s AND/OR graph,matrices for task-skill,worker-skill,precedence relationships,and disassembly correlations are developed.A multi-objective discrete chemical reaction optimization algorithm is designed.To enhance solution diversity,improvements are made to four reactions:decomposition,synthesis,intermolecular ineffective collision,and wall invalid collision reaction,completing the evolution of molecular individuals.The established model and improved algorithm are applied to ball pen,flashlight,washing machine,and radio combinations,respectively.Introducing a Collaborative Resource Allocation(CRA)strategy based on a Decomposition-Based Multi-Objective Evolutionary Algorithm,the experimental results are compared with four classical algorithms:MOEA/D,MOEAD-CRA,Non-dominated Sorting Genetic Algorithm Ⅱ(NSGA-Ⅱ),and Non-dominated Sorting Genetic Algorithm Ⅲ(NSGA-Ⅲ).This validates the feasibility and superiority of the proposed algorithm in parallel disassembly production lines.
文摘The human scalp harbors a diverse range of microbiome,much like other skin surfaces,where both beneficial and harmful microorganisms coexist.This study explores the possibility of balancing key scalp microorganisms,particularly Staphylococcus epidermidis,Staphylococcus aureus and Malassezia species.While Staphylococcus epidermidis plays a beneficial role in maintaining scalp health by producing antimicrobial proteins and supporting the skin barrier,Staphylococcus aureus is identified as a pathogen linked to skin infections and dandruff formation.Malassezia fungi degrade triglycerides in sebum into unsaturated fatty acids,exacerbating scalp conditions like dandruff.In order to promote the beneficial microbe while inhibit the harmful ones,we investigated the combination of 1.0 mM pyrrolidone carboxylate-zinc(PCA-Zn),0.2%malt oligosaccharides(MT:corn-derived oligosaccharide mainly containing maltotetraose)and 0.05 mM Hinokitiol on its microbial activity,which significantly enhanced the growth of Staphylococcus epidermidis while inhibiting both Staphylococcus aureus and Malassezia,offering insights into promising strategies for scalp care.
文摘With the continuous expansion of the data center network scale, changing network requirements, and increasing pressure on network bandwidth, the traditional network architecture can no longer meet people’s needs. The development of software defined networks has brought new opportunities and challenges to future networks. The data and control separation characteristics of SDN improve the performance of the entire network. Researchers have integrated SDN architecture into data centers to improve network resource utilization and performance. This paper first introduces the basic concepts of SDN and data center networks. Then it discusses SDN-based load balancing mechanisms for data centers from different perspectives. Finally, it summarizes and looks forward to the study on SDN-based load balancing mechanisms and its development trend.
文摘Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging population.Posture and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous mechanisms.To effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory signals.The mechanisms which underpin the integration of these multisensory signals are the principal topic of the present work.Existing multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older adults.Insufficient emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and balance.In the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s disease.We also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older adults.Lastly,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.
文摘BACKGROUND Liver transplantation aims to increase the survival of patients with end-stage liver diseases and improve their quality of life.The number of organs available for transplantation is lower than the demand.To provide fair organ distribution,predictive mortality scores have been developed.AIM To compare the Acute Physiology and Chronic Health Evaluation IV(APACHE IV),balance of risk(BAR),and model for end-stage liver disease(MELD)scores as predictors of mortality.METHODS Retrospective cohort study,which included 283 adult patients in the postoperative period of deceased donor liver transplantation from 2014 to 2018.RESULTS The transplant recipients were mainly male,with a mean age of 58.1 years.Donors were mostly male,with a mean age of 41.6 years.The median cold ischemia time was 3.1 hours,and the median intensive care unit stay was 5 days.For APACHE IV,a mean of 59.6 was found,BAR 10.7,and MELD 24.2.The 28-day mortality rate was 9.5%,and at 90 days,it was 3.5%.The 28-day mortality prediction for APACHE IV was very good[area under the curve(AUC):0.85,P<0.001,95%CI:0.76-0.94],P<0.001,BAR(AUC:0.70,P<0.001,95%CI:0.58–0.81),and MELD(AUC:0.66,P<0.006,95%CI:0.55-0.78),P<0.008.At 90 days,the data for APACHE IV were very good(AUC:0.80,P<0.001,95%CI:0.71–0.90)and moderate for BAR and MELD,respectively,(AUC:0.66,P<0.004,95%CI:0.55–0.77),(AUC:0.62,P<0.026,95%CI:0.51–0.72).All showed good discrimination between deaths and survivors.As for the best value for liver transplantation,it was significant only for APACHE IV(P<0.001).CONCLUSION The APACHE IV assessment score was more accurate than BAR and MELD in predicting mortality in deceased donor liver transplant recipients.
文摘The Brief Interactive Optimism Scale (BIOS-G), recently published, was developed to measure optimism based on the interactive personality styles theory in the general population of Mexican adults. It has been validated in both the general population in Mexico and other Latin American countries. This study aims to further consolidate the validity of the BIOS-G in a specific population. The objectives are to assess the psychometric properties of its items, validate its unidimensional structure, describe its distribution, verify its internal consistency, and examine its direct relationship with affective balance and positive affect, as well as its inverse relationship with emotional exhaustion and negative affect among Mexican university teachers. The BIOS-G, the CESQT emotional exhaustion subscale, and Scale of Positive and Negative Experience (SPANE) were administered to a non-probability sample of 213 Mexican university teachers. All items demonstrated discriminative power and internal consistency. The scale showed internal consistency (Green-Yang ordinal ω = 0.74 and McDonald ordinal ω = 0.88). The one-factor model presented good to acceptable fit to the data, with an average variance extracted of 0.65. Its distribution was negatively skewed and mesokurtic. The BIOS-G correlated directly with SPANE’s affective balance and positive emotional experiences and inversely with negative emotional experiences and emotional exhaustion, with moderate strengths of association. Its mean score was higher in men than in women and correlated positively with age. It is concluded that the BIOS-G demonstrates internal consistency and validity evidence among Mexican university teachers, and its use in this specific population is recommended.
基金supported by the National Natural Science Foundation of China(42177341)the Natural Science Basic Research Program of Shanxi,China(202203021222138).
文摘Organic material combined with inorganic fertilizer has been shown to greatly improve crop yield and maintain soil fertility globally. However, it remains unclear if crop yield and soil fertility can be sustained in the long term under the combined application of organic and inorganic fertilizers. Three long-term field trials were conducted to investigate the effects of organic amendments on the grain sustainable yield index(SYI), soil fertility index(SFI)and nutrient balance in maize–wheat cropping systems of central and southern China during 1991–2019. Five treatments were included in the trials: 1) no fertilization(control);2) balanced mineral fertilization(NPK);3) NPK plus manure(NPKM);4) high dose of NPK plus manure(1.5NPKM);and 5) NPK plus crop straw(NPKS). Over time, the grain yields of wheat and maize showed an increasing trend in all four fertilization treatments at the Yangling(YL) and Zhengzhou(ZZ) locations, while they declined at Qiyang(QY). The grain yield in the NPKM and 1.5NPKM treatments gradually exceeded that of the NPK and NPKS treatments at the QY site. The largest SYI was recorded in the NPKM treatment across the three sites, suggesting that inorganic fertilizer combined with manure can effectively improve crop yield sustainability. Higher SYI values were recorded at the YL and ZZ sites than at the QY site, possibly because the soil was more acid at QY. The key factors affecting grain yield were soil available phosphorus(AP) and available potassium(AK) at the YL and ZZ sites, and pH and AP at the QY site.All fertilization treatments resulted in soil N and P surpluses at the three sites, but soil K surpluses were recorded only at the QY site. The SFI was greater in the 1.5NPKM, NPKM and NPKS treatments than in the NPK treatment by 13.3–40.0 and 16.4–63.6% at the YL and ZZ sites, respectively, and was significantly higher in the NPKM and 1.5NPKM treatments than in the NPK and NPKS treatments at the QY site. A significant, positive linear relationship was found between SFI and crop yield, and SYI and nutrient balance, indicating that grain yield and its sustainability significantly increased with increasing soil fertility. The apparent N, P and K balances positively affected SFI.This study suggests that the appropriate amount of manure mixed with mineral NPK fertilizer is beneficial to the development of sustainable agriculture, which effectively increases the crop yield and yield sustainability by improving soil fertility.
基金Chongqing Sports Scientific Research Project“Research and Development of Balance Rhythm Dance and Its Application in Reducing Fall Risk in Older Women”(Project No.D202209)Chongqing Nursing Vocational College College-level Project“Research on the Talent Training Model of Field Engineers in the Intelligent Health Care Sector Based on Rehabilitation Assistive Devices under the‘Integration of Science and Education’Approach”(Project No.Y202307)+1 种基金Chongqing Science and Technology Bureau Research Project“Investigating the Impact of Electro-acupuncture Applied to Antagonist Muscles on Walking Ability in Stroke Patients with Hemiplegia Based on the Principle of Reciprocal Inhibition”(Project No.CSTC2019JXJL130019)Chongqing Traditional Chinese Medicine Hospital Research Project“The Alterations in the Pelvic Floor Muscle Group Following Acupuncture Treatment for Postpartum Stress Urinary Incontinence Were Evaluated Using SWE Technology”(Project No.jxyn2021-2-23)。
文摘Objective: To investigate the effect of a self-developed balance rhythm dance program on the rehabilitation of motor function and the reduction of fall risk in elderly women with diminished balance function. Methods: Fifty elderly women with reduced balance function, admitted to the Qingbar Elderly Care Center of Chongqing Medical University from December 2022 to December 2023, were randomly selected and divided into two groups. The aerobic exercise group (25 patients) received traditional treatment and rehabilitation nursing, while the balance rhythm dance intervention group (25 patients) received the balance rhythm dance intervention in addition to traditional treatment and rehabilitation nursing. The Unified Parkinson’s Disease Rating Scale (UPDRS) and Berg Balance Scale (BBS) were used as evaluation indicators to compare the intervention effects between the two groups. Results: The data revealed that the balance rhythm dance intervention significantly improved the motor ability and balance function of elderly women in the intervention group (P < 0.01), with statistically significant differences observed. Conclusion: The balance rhythm dance program plays a critical role in promoting the rehabilitation of motor function and balance ability in elderly women, effectively enhancing their quality of life.
基金funded by the Study on enhanced heat transfer mechanism of low-permeability carbonate rocks under in-situ conditions under Grant number YK202305the National Natural Science Foundation of China under Grant number 42272350the Geothermal Survey Project of the China Geological Survey under Grant number DD20221676.
文摘Xiong'an New Area boasts abundant geothermal resources,with widespread Jixianian geother-mal reservoirs serving as key targets for exploration and development.Zoning geothermal resources helps characterize their distribution and attributes,offering critical guidance for their sustainable exploitation and utilization.This study integrates data from drilling and production tests across 21 geothermal wells to analyze the Jixianian strata,including depth,thickness,temperature,single-well water yield,Groundwater Level Depth(GWD),and Total Dissolved Solids(TDS).Employing fuzzy mathematics,a zoning analysis was performed,yielding quantitative evaluation scores and delineating favorable zones for development.Key findings include:(1)Geothermal reservoirs in the Rongcheng and Niutuozhen uplifts exhibit shallow burial depths,substantial thicknesses,high productivity,and relatively low temperatures,making them highly suitable for large-scale geothermal exploitation;(2)Zones with high resource potential but uncertain conditions require further exploration to mitigate development risks;(3)Areas near the Rongcheng fault or Jixianian strata buried deeper than 4,000 m are recommended for deferred exploitation;(4)Comprehensive evaluation reveals that the Jixianian carbonate geothermal reservoirs in Xiong'an New Area manifest 168 geothermal resources of 5,370.31×10 J,geothermal fluid reserves of 101.17×10 m3,and recoverable fluid 4 reserves of 93.41×10 m3/d under balanced extraction and reinjection.Recoverable geothermal heat 164 amounts to 9.36×10 J/a,equivalent to 319.4×10 t/a of standard coal.This study provides valuable insights into the exploration and sustainable exploitation of deep geothermal reservoirs in Xiong'an New Area,enhancing resource utilization and contributing to the development of a green and sustainable Xiong'an New Area.
基金funded by the National Natural Science Foundation of China(32272513 and 31770156)the Natural Sciences and Engineering Research Council of Canada(Discovery Grant,RGPIN-2016-05356)the Canadian Foundation for Innovation(Discovery Grant,227398-2011)。
文摘Oxidation of self-stored carbohydrates and lipids provides the energy for the rapid morphogenetic transformation during asexual and infection-related development in Pyricularia oryzae,which results in intracellular accumulation of reducing equivalents NADH and FADH_(2),requiring a cytosolic shuttling machinery towards mitochondria.Our previous studies identified the mitochondrial D-lactate dehydrogenase MoDld1 as a regulator to channel the metabolite flow in conjunction with redox homeostasis.However,the regulator(s)facilitating the cytosolic redox balance and the importance in propelling nutrient metabolite flow remain unknown.The G-3-P shuttle is a conserved machinery transporting the cytosolic reducing power to mitochondria.In P.oryzae,the mitochondrial G-3-P dehydrogenase Gpd2 was required for cellular NAD^(+)/NADH balance and fungal virulence.In this study,we relocate the mitochondrial G-3-P dehydrogenase Gpd2 to the cytosol for disturbing cytosolic redox status.Our results showed overexpression of cytosolic gpd2^(Δmts)without the mitochondrial targeted signal(MTS)driven by Ribosomal protein 27 promoter(PR27)exerted conflicting regulation of cellular oxidoreductase activities compared to theΔModld1 deletion mutant by RNA-seq and prevented the conidiation and pathogenicity of P.oryzae.Moreover,overexpression of gpd2^(Δmts)caused defects in glycogen and lipid mobilization underlying asexual and infectious structural development associated with decreased cellular NADH production and weakened anti-oxidation activities.RNA-seq and non-targeted metabolic profiling revealed down-regulated transcriptional activities of carbohydrate metabolism and lower abundance of fatty acids and secondary metabolites in RP27:gpd2^(Δmts).Thus,our studies indicate the essential role of cytosolic redox control in nutrient metabolism fueling the asexual and infection-related development in P.oryzae.
文摘In this paper, an identification method to estimate the unbalances is introduced, which is based on the boundary element method (BEM). By using the vibration response measured at some points on the flexible rotor the unbalances can be identified conveniently. Therefore, the rotor can be balanced without test runs.
基金supported in part by National Natural Science Foundation of China (No.61401331,No.61401328)111 Project in Xidian University of China(B08038)+2 种基金Hong Kong,Macao and Taiwan Science and Technology Cooperation Special Project (2014DFT10320,2015DFT10160)The National Science and Technology Major Project of the Ministry of Science and Technology of China(2015zx03002006-003)FundamentalResearch Funds for the Central Universities (20101155739)
文摘The Internet of Vehicles(IoV)has been widely researched in recent years,and cloud computing has been one of the key technologies in the IoV.Although cloud computing provides high performance compute,storage and networking services,the IoV still suffers with high processing latency,less mobility support and location awareness.In this paper,we integrate fog computing and software defined networking(SDN) to address those problems.Fog computing extends computing and storing to the edge of the network,which could decrease latency remarkably in addition to enable mobility support and location awareness.Meanwhile,SDN provides flexible centralized control and global knowledge to the network.In order to apply the software defined cloud/fog networking(SDCFN) architecture in the IoV effectively,we propose a novel SDN-based modified constrained optimization particle swarm optimization(MPSO-CO) algorithm which uses the reverse of the flight of mutation particles and linear decrease inertia weight to enhance the performance of constrained optimization particle swarm optimization(PSO-CO).The simulation results indicate that the SDN-based MPSO-CO algorithm could effectively decrease the latency and improve the quality of service(QoS) in the SDCFN architecture.
基金Supported by National Natural Scie nce Foun dation of China(Grant No.51875031)Youth Backb one Personal Project of Beijing(Grant No.2017000020124G018).
文摘Imbalance vibration is a typical failure mode of rotational machines and has significant negative effects on the efficiency,accuracy,and service life of equipment.To automatically reduce the imbalance vibration during the operational process,different types of active balancing actuators have been designed and widely applied in actual production.However,the existing electromagnetic-ring active balancing actuator is designed based on an axial excitation structure which can cause structural instability and has low electromagnetic driving efficiency.In this paper,a novel radial excitation structure and the working principle of an electromagnetic-ring active balancing actuator with a combined driving strategy are presented in detail.Then,based on a finite element model,the performance parameters of the actuator are analyzed,and reasonable design parameters are obtained.Self-locking torque measurements and comparative static and dynamic experiments are performed to validate the self-locking torque and driving efficiency of the actuator.The results indicate that this novel active balancing actuator has sufficient self-locking torque,achieves normal step rotation at 2000 r/min,and reduces the driving voltage by 12.5%.The proposed novel balancing actuator using radial excitation and a combination of permanent magnets and soft-iron blocks has improved electromagnetic efficiency and a more stable and compact structure.
基金support and help of many individuals in the SASTRA University
文摘In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. The objective of this work aims in reducing the number of workstations, work load index between stations and within each station. As manual contribution of workers in final assembly line is more, ergonomics is taken as an additional objective function. Ergonomic risk level of a workstation is evaluated using a parameter called accumulated risk posture(ARP), which is calculated using rapid upper limb assessment(RULA) check sheet. This work is based on the case study of an MMAL problem in Rane(Madras) Ltd.(India), in which a problem based genetic algorithm(GA) has been proposed to minimize the mentioned objectives. The working of the genetic operators such as selection, crossover and mutation has been modified with respect to the addressed MMAL problem. The results show that there is a significant impact over productivity and the process time of the final assembled product, i.e., the rate of production is increased by 39.5% and the assembly time for one particular model is reduced to 13 min from existing 18 min. Also, the space required using the proposed assembly line is only 200 m2 against existing 350 m2. Further, the algorithm helps in reducing workers fatigue(i.e., ergonomic friendly).
基金supported by National Science and Technology Support Program of China (Grant No. 2012BAF15G00)
文摘High level architecture(HLA) is the open standard in the collaborative simulation field. Scholars have been paying close attention to theoretical research on and engineering applications of collaborative simulation based on HLA/RTI, which extends HLA in various aspects like functionality and efficiency. However, related study on the load balancing problem of HLA collaborative simulation is insufficient. Without load balancing, collaborative simulation under HLA/RTI may encounter performance reduction or even fatal errors. In this paper, load balancing is further divided into static problems and dynamic problems. A multi-objective model is established and the randomness of model parameters is taken into consideration for static load balancing, which makes the model more credible. The Monte Carlo based optimization algorithm(MCOA) is excogitated to gain static load balance. For dynamic load balancing, a new type of dynamic load balancing problem is put forward with regards to the variable-structured collaborative simulation under HLA/RTI. In order to minimize the influence against the running collaborative simulation, the ordinal optimization based algorithm(OOA) is devised to shorten the optimization time. Furthermore, the two algorithms are adopted in simulation experiments of different scenarios, which demonstrate their effectiveness and efficiency. An engineering experiment about collaborative simulation under HLA/RTI of high speed electricity multiple units(EMU) is also conducted to indentify credibility of the proposed models and supportive utility of MCOA and OOA to practical engineering systems. The proposed research ensures compatibility of traditional HLA, enhances the ability for assigning simulation loads onto computing units both statically and dynamically, improves the performance of collaborative simulation system and makes full use of the hardware resources.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2008 AA04Z114)
文摘Measurement error of unbalance＇s vibration response plays a crucial role in calibration and on-line updating of influence coefficient（IC）. Focusing on the two problems that the moment estimator of data used in calibration process cannot fulfill the accuracy requirement under small sample and the disturbance of measurement error cannot be effectively suppressed in updating process, an IC calibration and on-line updating method based on hierarchical Bayesian method for automatic dynamic balancing machine was proposed. During calibration process, for the repeatedly-measured data obtained from experiments with different trial weights, according to the fact that measurement error of each sensor had the same statistical characteristics, the joint posterior distribution model for the true values of the vibration response under all trial weights and measurement error was established. During the updating process, information obtained from calibration was regarded as prior information, which was utilized to update the posterior distribution of IC combined with the real-time reference information to implement online updating. Moreover, Gibbs sampling method of Markov Chain Monte Carlo（MCMC） was adopted to obtain the maximum posterior estimation of parameters to be estimated. On the independent developed dynamic balancing testbed, prediction was carried out for multiple groups of data through the proposed method and the traditional method respectively, the result indicated that estimator of influence coefficient obtained through the proposed method had higher accuracy; the proposed updating method more effectively guaranteed the measurement accuracy during the whole producing process, and meantime more reasonably compromised between the sensitivity of IC change and suppression of randomness of vibration response.
基金supported by the National Natural Science Foundation of China(No.61163058No.61201250 and No.61363006)Guangxi Key Laboratory of Trusted Software(No.KX201306)
文摘In order to balancing based on data achieve dynamic load flow level, in this paper, we apply SDN technology to the cloud data center, and propose a dynamic load balancing method of cloud center based on SDN. The approach of using the SDN technology in the current task scheduling flexibility, accomplish real-time monitoring of the service node flow and load condition by the OpenFlow protocol. When the load of system is imbalanced, the controller can allocate globally network resources. What＇s more, by using dynamic correction, the load of the system is not obvious tilt in the long run. The results of simulation show that this approach can realize and ensure that the load will not tilt over a long period of time, and improve the system throughput.
基金The authors are thankful for the support of Taif University Researchers Supporting Project No.(TURSP-2020/10),Taif University,Taif,Saudi Arabia.Taif University Researchers Supporting Project No.(TURSP-2020/10),Taif University,Taif,Saudi Arabia.
文摘In Software-Dened Networks(SDN),the divergence of the control interface from the data plane provides a unique platform to develop a programmable and exible network.A single controller,due to heavy load trafc triggered by different intelligent devices can not handle due to it’s restricted capability.To manage this,it is necessary to implement multiple controllers on the control plane to achieve quality network performance and robustness.The ow of data through the multiple controllers also varies,resulting in an unequal distribution of load between different controllers.One major drawback of the multiple controllers is their constant conguration of the mapping of the switch-controller,quickly allowing unequal distribution of load between controllers.To overcome this drawback,Software-Dened Vehicular Networking(SDVN)has evolved as a congurable and scalable network,that has quickly achieved attraction in wireless communications from research groups,businesses,and industries administration.In this paper,we have proposed a load balancing algorithm based on latency for multiple SDN controllers.It acknowledges the evolving characteristics of real-time latency vs.controller loads.By choosing the required latency and resolving multiple overloads simultaneously,our proposed algorithm solves the loadbalancing problems with multiple overloaded controllers in the SDN control plane.In addition to the migration,our algorithm has improved 25%latency as compared to the existing algorithms.
基金Supported by the National Natural Science Foundation of China （No. 50635010） and the National High Technology Research and Development Program of China （ No. 2007AA04Z422 ）.
文摘An active balancing technology has been applied to solve the severe vibration caused by sudden unbalance in rotating machineries during their working process. First, based on the generation principle of sudden unbalance, a simulation test stand with a sudden unbalance generation device was set up. Then, the balancing planes were optimized by using the finite element method （FEM） to determine the position for balancing device installation. Finally, the active balancing experiments were carried out on the test stand. The experimental results indicate that the vibration response caused by sudden unbalance can be decreased from 77μm to 8μm by using the active balancing device, and the vibration amplitude reduction was up to 89.6%. From this example, it can be concluded that the active balancing device, which is installed on a proper position of the rotor, can effectively control the random transient synchronous vibration, demonstrating its high value in engineering practice.
基金Supported by the National Natural Suience Foundation of China(No.51775030,91860126).
文摘Mass imbalance-induced vibration affects the rotating machinery very large,especially the highspeed types.Off-line balancing techniques have been widely developed for rejecting unbalance-induced vibration but do not eliminate unbalanced vibration in the working state.Moreover,multiple start-stops are required in off-line balancing techniques.Therefore,research on an efficient electromagnetically-driven auto-balancer is carried out in the present work,and an internal excitation actuator is designed in this balancer.The electromagnetic characteristics of the two copper coil bobbins in the internal excitation actuator are compared and analyzed.The permanent magnets inside the actuator are simulated and analyzed with different sections of round,rectangular,and elliptical.And the results show that the elliptic type has the largest self-locking force.Finally,the dynamic balance test is performed on a test bench equipped with a designed electromagnetic balancing actuator,and the unbalance vibration is reduced from 130.23 μm to 5.98 μm.
