An OpenFlow-Based Load Balancing Strategy in SDN

In today’s datacenter network,the quantity growth and complexity increment of traffic is unprecedented,which brings not only the booming of network development,but also the problem of network performance degradation,such as more chance of network congestion and serious load imbalance.Due to the dynamically changing traffic patterns,the state-of the-art approaches that do this all require forklift changes to data center networking gear.The root of problem is lack of distinct strategies for elephant and mice flows.Under this condition,it is essential to enforce accurate elephant flow detection and come up with a novel load balancing solution to alleviate the network congestion and achieve high bandwidth utilization.This paper proposed an OpenFlow-based load balancing strategy for datacenter networks that accurately detect elephant flows and enforce distinct routing schemes with different flow types so as to achieve high usage of network capacity.The prototype implemented in Mininet testbed with POX controller and verify the feasibility of our load-balancing strategy when dealing with flow confliction and network degradation.The results show the proposed strategy can adequately generate flow rules and significantly enhance the performance of the bandwidth usage compared against other solutions from the literature in terms of load balancing.

Upcycling of phosphogypsum waste for efficient zinc-ion batteries

Zinc metal is a promising anode material for next-generation aqueous batteries,but its practical application is limited by the formation of zinc dendrite.To prevent zinc dendrite growth,various Zn^(2+)-conducting but water-isolating solid-electrolyte interphase(SEI)films have been developed,however,the required high-purity chemical materials are extremely expensive.In this work,phosphogypsum(PG),an industrial byproduct produced from the phosphoric acid industry,is employed as a multifunctional protective layer to navigate uniform zinc deposition.Theoretical and experimental results demonstrate that PG-derived CaSO_(4)2H_(2)O can act as an artificial SEI layer to provide fast channels for Zn^(2+)transport.Moreover,CaSO_(4)2H_(2)O could release calcium ions(Ca^(2+))due to its relatively high Kspvalue,which have a higher binding energy than that of Zn^(2+)on the Zn surface,thus preferentially adsorbing to the tips of the protuberances to force zinc ions to nucleate at inert region.As a result,the Zn@PG anode achieves a high Coulombic efficiency of 99.5%during 500 cycles and long-time stability over 1000 hours at 1 m A cm^(-2).Our findings will not only construct a low-cost artificial SEI film for practical metal batteries,but also achieve a high-value utilization of phosphogypsum waste.

Effects of Three Nitrification Inhibitors on the Nitrogen Conversion in Purple Soil and Its Effect on the Nitrogen Uptake of Citrus Seedlings

Experiments were carried out to study the effects of nitrification inhibitors (NI) on the transformation of soil nitrogen (N) in purple soil and the effects on the N accumulation in different organs of citrus seedlings. In incubation and pot experiments, the rate of nitrification inhibitors 2-chloro-6-trichloro-methyl pyridine (Nitrapyrin), 3,4-dimethylpyrazole phosphate (DMPP) and dicyandiamide (DCD) was 2.4%, 1.0% and 5.0% of N rate, respectively. The trend of different nitrification inhibitors on ammonium nitrogen ( NH+4-N ), nitrate nitrogen ( NO-3-N ) content and pH was compared in incubation experiment;and the effect of different NI on the dry matter quality, N uptake of citrus seedling was studied in pot experiment. The results showed that NI could significantly inhibit soil nitrification in the early culture period (p DMPP > En (calculated as nitrogen application rate). Application of NI increased the height and dry matter accumulation, N accumulation of citrus seedling grown in pot experiment. Thus, application of NI would be helpful for improving N use efficiency in purple soil which is one of major soil types for citrus production in China.

Hewei Jiangni granule alleviates visceral hypersensitivity in a rat model of non-erosive reflux disease via transient receptor potential channel signaling

Objective:To uncover the underlying mechanism of Hewei Jiangni granule(HWJNG)on non-erosive reflux disease(NERD)treatment by examining histological changes,gastrointestinal neurochemicals release and visceral hypersensitivity-related receptor expression in NERD model rats.Methods:A NERD rat model was established via a combination of basal sensitization and acid perfusion.HWJNG treatments at different doses were then administered.Pathological changes to tissues,mast cell(MC)activation,serum levels of esophageal visceral hypersensitivity-related neurochemicals,and transient receptor potential(TRP)receptor mRNA and protein levels were investigated.Results:Compared with the control group,the expression of tryptase in MCs,the changes of intercellular space,and the serum levels of substance P(SP),calcitonin gene-related peptides(CGRP)and proteinaseactivated receptor 2(PAR2)increased in the model group(all P<.05).The expression of TRP vanilloid 1(Trpv1)mRNA decreased in esophagus and dorsal root ganglia(DRG)of the model group(P=.030&P=.013),and the expression of TRP melastatin channel subfamily member 8(Trpm8)mRNA decreased in the esophagus of model group(P<.01).The level of esophageal TRPV1 protein increased in the model group(P<.01)and the level of TRPM8 protein decreased in esophagus and DRG of the model group(both P<.05).Compared with the model group,the serum levels of SP,CGRP,and PAR2 in the mediumdose HWJNG group showed significant decreases(all P<.05).The expression of Trpv1 mRNA in esophagus and DRG of the HWJNG groups and the Omeprazole group remarkably decreased(all P<.05),as was the expression of Trpm8 mRNA in esophagus of the HWJNG groups(all P<.05).Conclusion:HWJNG alleviated visceral hypersensitivity in NERD model rats by regulating TRP-mediated signaling.Our results indicate that HWJNG has potential as a therapeutic agent for NERD.

Arbuscular Mycorrhizal Fungus Mediate Changes in Mycorrhizosphere Soil Aggregates

Many studies have shown that arbuscular mycorrhizal (AM) fungus has an important role in soil aggregate formation and stabilization. While most studies about the effects of AM fungus on soil aggregate have experimental set-ups in single pots or containers with two compartments, these studies cannot differentiate the effects of roots, mycorrhizal roots or hyphae. In this study we used containers with four compartments to split the roots and quantitatively compare the change of soil aggregate in the mycorrhizosphere soil, rhizosphere soil, hyphosphere soil and bulk soil. Our results demonstrate a significant positive correlation among hyphal length density, easily extractable glomalin (EEG) and aggregate mean weight diameter (MWD), geometric mean diameter (GMD) and percentage of soil macroaggregate with a diameter larger than 0.25 mm (R0.25). The GMD and MWD of R0.25 in the hyphal compartment were higher than those in the non-inoculated root compartment, but were lower than those in the mycorrhizal compartment. This suggests the mycorrhizal hyphae had a greater effect than the non-inoculated roots, but less of an effect than the mycorrhizal roots on the formation and stabilization of soil aggregate. The results reveal that plant roots, mycorrhizal roots and mycorrhizal hyphae contribute to aggregate stability in individual ways and that their effects are additive, creating a synergistic stabilizing effect.

Workload Allocation Based on User Mobility in Mobile Edge Computing

Mobile Edge Computing(MEC)has become the most possible network architecture to realize the vision of interconnection of all things.By offloading compute-intensive or latency-sensitive applications to nearby small cell base stations(sBSs),the execution latency and device power consumption can be reduced on resource-constrained mobile devices.However,computation delay of Mobile Edge Network(MEN)tasks are neglected while the unloading decision-making is studied in depth.In this paper,we propose a workload allocation scheme which combines the task allocation optimization of mobile edge network with the actual user behavior activities to predict the task allocation of single user.We obtain the next possible location through the user's past location information,and receive the next access server according to the grid matrix.Furthermore,the next time task sequence is calculated on the base of the historical time task sequence,and the server is chosen to preload the task.In the experiments,the results demonstrate a high accuracy of our proposed model.

MoTransFrame:Model Transfer Framework for CNNs on Low-Resource Edge Computing Node

Deep learning technology has been widely used in computer vision,speech recognition,natural language processing,and other related fields.The deep learning algorithm has high precision and high reliability.However,the lack of resources in the edge terminal equipment makes it difficult to run deep learning algorithms that require more memory and computing power.In this paper,we propose MoTransFrame,a general model processing framework for deep learning models.Instead of designing a model compression algorithm with a high compression ratio,MoTransFrame can transplant popular convolutional neural networks models to resources-starved edge devices promptly and accurately.By the integration method,Deep learning models can be converted into portable projects for Arduino,a typical edge device with limited resources.Our experiments show that MoTransFrame has good adaptability in edge devices with limited memories.It is more flexible than other model transplantation methods.It can keep a small loss of model accuracy when the number of parameters is compressed by tens of times.At the same time,the computational resources needed in the reasoning process are less than what the edge node could handle.

A Tabu Search Algorithm for Fast Restoration of Large Area Breakdown in Distribution Systems

To restore the distribution systems in emergency states with the minimum load shedding, a novel Tabu search approach is put forward. The set of tripped switches is used as candidate solution. Some virtual tripped nodes are defined at the ends of the terminal nodes and by the source nodes. The neighborhood searching is committed by moving a tripped switch to the adjacent node of its upper stream and down stream, respectively. A Tabu list is formed for the tripped switches. The index is to energize as much as possible loads with as less as possible operated times. The electrical limitations and the voltage criterions are used as constrictions. The global aspiration criterion is adopted. An example is given, which shows that the proposed approach is feasible and can deal with complicated indexes.

Greenhouse gas emissions mitigation and economic viability of sugar crops in China

Climate change mitigation is a major challenge of human society.Currently,to this end,many countries including China are committed to achieving carbon neutrality within a few decades.China is a major sugarcane and sugar beet producing country and has one of the largest carbon footprint for sugarcane and sugar beet production globally.A comprehensive study was conducted on sugarcane and sugar beet crops grown in China for greenhouse gas(GHG)emissions mitigation potential,economic crop production from a sustainable sugar production perspective.Long-term trend analysis showed that yield and GHG emissions of sugarcane and sugar beet crops increased but the ratio of income to cost declined.Structural equation model analysis revealed nitrogen fertilizer and labor as the major drivers of GHG emissions for both sugarcane and sugar beet.For sugarcane and sugar beet,the path coefficient of N fertilizer were‒0.964 and‒0.835 and that of labor were 0.771 and 0.589,respectively.By transitioning the current cropping system to an improved model with optimized labor,N input and machinery use,the GHG emissions and total annual cost of sugarcane and sugar beet production can be reduced by 32%and 24%,respectively,by 2030,compared to a business-as-usual scenario.This is the first integrated and comparative study of environmental and economic sustainability of sugarcane and sugar beet production in China.These findings will enable all stakeholders of Chinese sugarcane and sugar beet industries to transform them into environmentally and economically sustainable sugar production.

Survey of Pedestrian Action Recognition Techniques for Autonomous Driving

The development of autonomous driving has brought with it requirements for intelligence,safety,and stability.One example of this is the need to construct effective forms of interactive cognition between pedestrians and vehicles in dynamic,complex,and uncertain environments.Pedestrian action detection is a form of interactive cognition that is fundamental to the success of autonomous driving technologies.Specifically,vehicles need to detect pedestrians,recognize their limb movements,and understand the meaning of their actions before making appropriate decisions in response.In this survey,we present a detailed description of the architecture for pedestrian action recognition in autonomous driving,and compare the existing mainstream pedestrian action recognition techniques.We also introduce several commonly used datasets used in pedestrian motion recognition.Finally,we present several suggestions for future research directions.

Integrating biochar and bacteria for sustainable remediation of metal-contaminated soils

Due to anthropogenic activities,heavy metal(HM)pollution in soils has increased,resulting in severe ecological problems and posing a constant threat to human health.Among various remediation methods,bacterial remediation is a relatively clean,efficient,and minimally negative approach.However,bacterial agents face multiple environmental stresses,making them challenging to achieve long-lasting and stable restoration effects.To address this issue,supportive organic substances such as biochar can be added to the soil with bacteria.According to bibliometric studies,integrating biochar and bacteria is extensively researched and widely used for HM-contaminated soil remediation.By integrating biochar and bacteria,heavy metals in the soil can be remediated,and soil conditions can be improved over time.Bacteria can also better promote plant growth or contribute effectively to phytoremediation processes when assisted by biochar.However,the remediation agents integrating biochar and bacteria are still some distance away from large-scale use because of their high cost and possible environmental problems.Therefore,further discussion on the interaction between biochar and bacteria and the integration approach,along with their remediation efficiency and environmental friendliness,is needed to achieve sustainable remediation of HM-contaminated soils by integrating biochar and bacteria.This paper discusses the potential mechanisms of biochar-bacteria-metal interactions,current advancements in biochar-bacteria combinations for HM-contaminated soil treatment,and their application in sustainable remediation,analyzes the interaction between biochar and bacteria and compares the remediation effect of different ways and feedstocks to integrate biochar and bacteria.Finally,future directions of biochar-bacteria combinations are presented,along with evidence and strategies for improving their commercialization and implementation.

Dynamics,stability,and control of a four-cable mount system for wind tunnel test

A four-cable mount system is proposed for full-model wind tunnel flutter tests,which may adjust the pitch and roll attitude of the aircraft scaled model and ensure that the model is not subjected to cable tension.The system provides sufficient support to simulate the free flight of the aircraft by applying appropriate spring stiffness and cable tensions.The proposed fourcable mount system is modeled based on Lagrange mechanics,and its dynamics equations consider aerodynamic effects.The singularity of the system and its bifurcation characteristics under flow conditions are analysed to determine the supercritical bifurcation phenomenon for different tension levels and distances from the front suspension point to the mass centre of the model.The mathematical expressions of the longitudinal flight stability of the cable mount system are derived by linearising the system dynamics equations using small perturbations.The influence of the cable tension,spring stiffness,suspension point position,and other factors on the flight stability of the aircraft are analysed.A feedforward control algorithm is proposed to minimize the total elastic potential energy of the system.The results show that the model is in the level flight state when the elastic potential energy of the four-cable mount system is minimized.A feedback control design method is proposed based on the Lyapunov stability theory to derive the closed-loop stability conditions.The system dynamics model that includes the aircraft rigid body model,flexible cables,pulleys,springs,aerodynamic model,and servo motor control is established using the flexible multibody dynamics method.A multibody dynamics solver and Simulink are used to simulate the attitude adjustment of the model in the wind tunnel and verify the supercritical bifurcation characteristics of the system and the effectiveness of the feedback and feedforward control.

PRICING OF LIBOR FUTURES BY MARTINGALE METHOD IN COX-INGERSOLL-ROSS MODEL

This paper considers the pricing of LIBOR futures in the Cox-Ingersoll-Ross(CIR)modelunder Pozdnyakov and Steele(2004)'s martingale framework for futures prices.Under the CIR modelfor short term interest rate,we prove that there exists a unique futures price process associated withthe terminal value and the standard financial market,and that this unique futures price process has amartingale representation.Moreover,a general closed-form pricing formula for LIBOR futures contractsis obtained in the CIR model.

Effects of tranexamic acid on vascular occlusive events and perioperative resuscitation in patients with atrial fibrillation undergoing total joint arthroplasty

To the Editor:Tranexamic acid(TXA)has recently become popular for use in orthopedic surgeries owing to its efficacy in reducing blood loss,transfusion rates,and mortality without increasing the risk of deep venous thrombosis.ll Although the ideal dosage and route for TXA administration remain unclear,it has become one of the most important parts of the perioperative blood conservation strategy.However,it remains controversial to prescribe TXA to patients with cardiovascular diseases,because of prothrombotic and proconvulsant effects,which potentially increases cardiovascular risk.