应用程序属性感知的Yarn资源调度模型研究

Hadoop应用程序存在计算密集属性和调度时间属性,但是Hadoop大数据平台集成的第二代资源管理器Yarn内置的三种资源调度器无法将相同属性的应用程序均衡分配到计算节点上,导致部分节点负载过高,出现严重的计算任务长尾效应。文中提出了一种应用程序属性感知的Yarn负载均衡调度模型——APB Scheduler。APB Scheduler自动感知应用程序属性,将相同属性应用程序的Container按照动态资源计划均衡分配到集群计算节点上,并使用NSGA-Ⅲ算法完成最优分配方案计算。实验结果表明,APB Scheduler解决了相同属性应用程序的Container分配倾斜问题,大幅提升了集群的性能和稳定性。

Analysis on the Characterization of the Twist Insertion Level and Its Effect of the Compact and Ring Spun Yarns

In this paper, the difference of the twist insertion levels of the compact and ring spun yarns of the same count is analyzed based on the relationship of the yarn twist factor to the twist angle and the bulk density. It is proposed that the relationship of the twist angle, twist level, and the yarn diameter should be synthetically considered when evaluating the twist insertion level of the compact yarn. The twist angle of the compact yarn is smaller than that of the ring yarn with the same twist insertion level. This results from the ordered fiber arrangement and compact structure of the compact yarn. Experiment was conducted to verify the conclusions. It is also discovered that the selection of the twist factor of the compact yarn, which can be usually lower than that of the ring yarn by 10%-15%, can be determined based on the yarn tensile strength.

Study on the Bending Properties of Woven Fabrics and Its Yarns

A theoretical analysis on the two extreme cases of yarn bending rigidity as well as the relationship between them is proposed. The significant influence of fiber-to-fiber interaction on yarn bending rigidity is revealed.Experimental observation on the relationship between fabric/yarn bending property and fiber fineness, yarn structure, fabric structure is given as we ll. Three problems are discussed and the following conclusion is thus obtained. There exists, similar t0 a rigid engineering rod, a linear relationship between yarn bending rigidity and the square of yarn fineness (expressed as yarn count in tex), but the increasing speed is much lower. Yarn bending rigidity in the fabric also to a great extent depends on the fabric density and yarn twist factor, and so on. Fabric's bending hysteresis primarily depends on its bending rigidity.

Multi-objective Optimal Trajectory and Placement of a Robot for Cotton Yarns Handling

This study deals with a robot manipulator for yarn bobbin handling in the cotton yarns lattice distortion modification system.The aim is to achieve an operation of yarn bobbin handling with minimal execution time,energy consumption and jerk in motion together.The placement of the robot,in relation to the yarn bobbin stations,is also optimized in conjunction of trajectory optimization.Three possible techniques for building the handling traj'ectory were considered:the quaternion spherical linear interpolation in Cartesian space,the quintic polynomial spline and quintic B-spline in joint space.The genetic algorithm(GA) was used to optimize the trajectories of the robot,with a penalty function to handle nonlinear constraints associated in the robot motion.Two simulations of the optimal trajectory in joint space and the placement of robot were carried out and the results obtained were presented and discussed.It is concluded that the quintic polynomial spline constructs a better trajectory in joint space and the proper placement of robot makes better performance.

Bendable tube-shaped supercapacitor based on reduced graphene oxide and Prussian blue coated carbon fiber yarns for energy storage

Carbon fiber yarns（CFY） are promising as a new type of flexible building blocks for the construction of flexible architectures for the energy storage applications. The main hurdle with CFY is how to make them high energy and power capable by using economically and environmentally viable materials. Here,we report reduced graphene oxide（r GO） and Prussian blue（PB） coated CFY, derived from a facile electrochemical process at room temperature for supercapacitor electrodes. The PB coated CFY and r GO coated CFY electrodes exhibit the excellent gravimetric capacitance of 339 F/g and 160.2 F/g, respectively, in aqueous KCl electrolyte in three-electrode cell configuration. When we coupled these electrodes inside the flexible plastic tube and separated by the electrolyte wet filter paper in order to construct flexible architecture, the resulting device delivers excellent specific energy of 52.1 Wh/kg and 26.5 Wh/kg with offering specific power of 3100 W/kg and 14400 W/kg respectively, under a wide operating potential of1.8 V with excellent rate capability. The device shows high tolerance towards bending, and retained its efficiency to the capacitance after being bent at an angle of 360° for 200 bending cycles.

VARIATION OF WOVEN FABRIC GEOMETRY——Non-uniform Flattening of Yarns

In previous research much effort has been devoted to the geometry of woven fabrics and relat-ed problems under the assumption of constant yarn configuration in fabric.This paper will first re-port that image crimp (yarn crimp measured by an image analysis method) seems larger than actualvalue.From the explanation of this result,the variation of yarn configuration in woven fabric dueto the non-uniform flattening is revealed.The significance of this actual structure of woven fabricsis discussed.It is believed that the variation of yarn configuration is very important for fabric per-formance,and may be an advantage for fabric quality.

Advances in Electrospun Nanofiber Yarns

In order to increase the application area of nanofibers,electrospun nanofiber yarns have drawn attention of many researchers around the globe.Once the production method of nanofiber yarn is mature enough to be universally accepted,many new gates of applications will open to the world.In this review,different electrospinning techniques of electrospun nanofiber yarns are divided into needle electrospinning and needleless electrospinning.Considering yarn twist as an important mechanism,needle electrospinning technique is further categorized into mechanical,electrical and field flow twisting methods.Moreover,parameters influencing the mechanical properties of electrospun nanofiber yarns are investigated.Methods of improving mechanical properties of nanofiber yarns are addressed,including hot-water-bath treatment,addition of carbon nanotubes(CNTs)and introducing regulators.Finally,applications of electrospun nanofiber yarns in different fields of smart textile and bioengineering are summed-up.In summary,challenges encountered in the industrialization of nanofiber yarns and future prospects are anticipated.

STRUCTURAL VARIATIONS OF HOLLOW SPINDLE WRAP SPUN YARNS

The structure of a hollow spindle wrap spun yarn depends greatly on the steadiness of bindertension and of balloon rotation.The two commonly used binder bobbin forms,the cop type andthe flanged type,both as sources of spinning condition fluctuation,are examined in order to revealtheir effects on the wrap spun yarn structure.False twist is introduced on hollow spindle spinningmachines in order to avoid strand breaks before it is tightly wrapped up.However,an investigationof the false twisti g-wrapping process shows that this inevitably causes irregular yarn tortuosity.

Relationship between Abrasiveness and Structure of Rotor and Ring Yarns

The friction and abrasion characters of yarn play veryimportant roles in the downstream processing and theend-use of products.With the development of rotoryarn and its application in the knitted products,theproblem of abrasion on the machine components causedby the processed rotor yarn has been paid more andmore attentions.This paper deals with the factors effectthe abrasiveness of rotor yarn and the comparison ofabrasive character between rotor yarn and ring yarn.

Studying the Mechanical Properties of Jute/Cotton Blended Yarns Using the Weibull Model

The phenomenon of a material failure varies with its gauge length in use. In the present study,the breaking strengths of J30/C70 and J55/C45 blended yarns spun by the ring spinning technology were investigated with the employment of the equations derived from the Weibull theory. The four probability estimators of the Weibull distribution were also evaluated. The results showed that the estimator (2a) was acceptable for calculating the Weibull modulus of the jute/cotton blended yarns. With the exception of breaking strength of the J30/C70 at the gauge length of 200 mm, the breaking strengths of both blended yarn could be predicted accurately by the Eqs.(9) or (10) in this paper.

BALANCING TORQUE OF SINGLES COTTON ROTOR YARNS

This paper reports a recent development of a yarn modification process to produce torque balanced singles spun yarns. Taking advantages of the core-sheath structure of unconventional spun yarns, we have developed a yarn modification process and applied it to singles yarns spun by rotor spinning. Torque free singles yarns have been produced from 100% cotton fibers. The spirality of resultant single jersey knit fabrics has been greatly reduced or, in some cases, completely eliminated. Properties and performance characteristics of both parent and modified yarns as well as their resultant fabrics have been evaluated including the yarn tensile properties, surface properties, handle, air permeability, burst strength, and pilling resistance of the fabrics.

Study on Wet Permeability Models of Yarns and Knitted Fabrics

Water transport through the pore structure of the knitted fabric can occur only in place where the fiber-water surface attraction force is greater than the water weight in the capillary. To investigate wet permeability of the knitted yarn in the fabric, a liquid transport model is established. The main factors which have significant influences on the liquid transport have been analyzed. It is derived from the argument that the optimal design for the knitted fabric with quick sweat transport property can be obtained.

TENSILE BEHAVIOUR OF ROTOR SPUN YARNS

This paper deals with the tensile behaviour of rotor spun yarns. Having regard to the spe-cial construction of rotor spun yarn, some modifications for Hearle’s theory have been made inorder to apply Hearle’ s theory to rotor spun yarn. The paper then goes into calculating thetensile curve and investigating the effect of main parameters and spinning conditions on thetensile behaviour of rotor spun yarn. It was found that the following facts are noteworthy forimproving the mechanical properties of rotor spun yarn: (1) Selecting suitable navel so as tocontrol the P. T. E. length within a reasonable range. (2) Improving the design of single fibresupply device to decrease the amount of spoiled fibre and hence increase the effective fibrelength. (3) Increasing spinning yarn tension without yarn break to enhance the fibre migrationratio. (4) For the rotor spun yarn of industrial use, it is the way to increase the yarn strengththat the rotor groove should be designed with the groove angle beneficial to decrease the yarnspecific volume.

The Effect of Gauge Length on Tenacity of Cotton Yarns

The tensile properties of cotton yarns are studied. A lot of data are gotten and analyzed. It indicates that the breaking strength of the yarns follows Weibull distribution. Then the effect of sample length on strength is analyzed using Weibull's statistics. The Weibull parameters are calculated through regression method.The breaking strength of the yarn at different sample length is predicted. Theoretical prediction conforms the experimental results very well.

SOME END-USES OF PURE RAMIE NOIL ROTOR YARNS

In the previous studies, the optimum technological combination has been obtained for producing coarse pure ramie noil yarns on rotor spinning system currently. Because of no yarn properties standard available at present for suchlike yarns, it is considered necessary to analyse the acceptability of coarse pure ramie noil rotor-spun yarns in terms of yarn properties before their products being developed. By the aid of a hypothetical concept "pure ramie noil ring-spun yarn", this paper draws the conclusion that the coarse pure ramie noil rotor-spun yarns are condsidered acceptable to a great extent; furthermore, it introduces 5 kinds of woven fabrics and 3 kinds of knitted fabrics successfully designed and developed from those yarns.

Dual-Ion Co-Regulation System Enabling High-Performance Electrochemical Artificial Yarn Muscles with Energy-Free Catch States

Artificial yarn muscles show great potential in applications requiring low-energy consumption while maintaining high performance. However, conventional designs have been limited by weak ion-yarn muscle interactions and inefficient “rocking-chair” ion migration. To address these limitations, we present an electrochemical artificial yarn muscle design driven by a dual-ion co-regulation system. By utilizing two reaction channels, this system shortens ion migration pathways, leading to faster and more efficient actuation. During the charging/discharging process, PF_6~- ions react with carbon nanotube yarn, while Li~+ ions react with an Al foil. The intercalation reaction between PF_6~- and collapsed carbon nanotubes allows the yarn muscle to achieve an energy-free high-tension catch state. The dual-ion coordinated yarn muscles exhibit superior contractile stroke, maximum contractile rate, and maximum power densities, exceeding those of “rocking-chair” type ion migration yarn muscles. The dual-ion co-regulation system enhances the ion migration rate during actuation, resulting in improved performance. Moreover, the yarn muscles can withstand high levels of isometric stress, displaying a stress of 61 times that of skeletal muscles and 8 times that of “rocking-chair” type yarn muscles at higher frequencies. This technology holds significant potential for various applications, including prosthetics and robotics.

Scalable Core–Sheath Yarn for Boosting Solar Interfacial Desalination Through Engineering Controllable Water Supply

Tailoring water supply to achieve confined heating has proven to be an effective strategy for boosting solar interfacial evaporation rates.However,because of salt clogging during desalination,a critical point of constriction occurs when controlling the water rate for confined heating.In this study,we demonstrate a facile and scalable weaving technique for fabricating core-sheath photothermal yarns that facilitate controlled water supply for stable and efficient interracial solar desalination.The core-sheath yarn comprises modal fibers as the core and carbon fibers as the sheaths.Because of the core-sheath design,remarkable liquid pumping can be enabled in the carbon fiber bundle of the dispersed superhydrophilic modal fibers.Our woven fabrics absorb a high proportion(92%)of the electromagnetic radiation in the solar spectrum because of the weaving structure and the carbon fiber sheath.Under one-sun(1 kW·m^(-2))illumination,our woven fabric device can achieve the highest evaporation rate(of 2.12kg·m^(-2)·h^(-1) with energy conversion efficiency:93.7%)by regulating the number of core-sheath yarns.Practical application tests demonstrate that our device can maintain high and stable desalination performance in a 5 wt%NaCl solution.

Design and Characterization of Electrical Connections for Conductive Yarns

The development of flexible and stretchable electronics has attracted much attention.As an important part of wearable electronic systems,the connection between conductive yarns and electronic components affects the stability and accuracy of their electrical reliability.In this paper,three different connections were attempted to electrically and mechanically link two conductive yarns,including soldering followed by waterborne polyurethane(WPU)encapsulation,coating of conductive silver adhesive with WPU encapsulation,as well as coating of conductive silver adhesive with polydimethylsiloxane(PDMS)encapsulation.The surface morphologies and electro-mechanical behaviors of the three created connected conductive yarns were characterized.Compared with their electro-mechanical behaviors of the established three connections,the connection with soldering remained electrically conductive to around 200%,which mainly came from the stress concentration between the stiff soldering and soft conductive yarns.However,the coating of conductive silver adhesive and encapsulated protection of PDMS can make the connected conductive yarns stretchable up to 300%with almost constant electrical resistance.

Yarn Quality Prediction for Small Samples Based on AdaBoost Algorithm

In order to solve the problems of weak prediction stability and generalization ability of a neural network algorithm model in the yarn quality prediction research for small samples,a prediction model based on an AdaBoost algorithm(AdaBoost model) was established.A prediction model based on a linear regression algorithm(LR model) and a prediction model based on a multi-layer perceptron neural network algorithm(MLP model) were established for comparison.The prediction experiments of the yarn evenness and the yarn strength were implemented.Determination coefficients and prediction errors were used to evaluate the prediction accuracy of these models,and the K-fold cross validation was used to evaluate the generalization ability of these models.In the prediction experiments,the determination coefficient of the yarn evenness prediction result of the AdaBoost model is 76% and 87% higher than that of the LR model and the MLP model,respectively.The determination coefficient of the yarn strength prediction result of the AdaBoost model is slightly higher than that of the other two models.Considering that the yarn evenness dataset has a weaker linear relationship with the cotton dataset than that of the yarn strength dataset in this paper,the AdaBoost model has the best adaptability for the nonlinear dataset among the three models.In addition,the AdaBoost model shows generally better results in the cross-validation experiments and the series of prediction experiments at eight different training set sample sizes.It is proved that the AdaBoost model not only has good prediction accuracy but also has good prediction stability and generalization ability for small samples.

Comparison of the Vortex and Ring Spun Cotton Yarns and Their Knitted Fabric Properties

Vortex spinning is an innovative air-jet spinning technology with promising features.A comparison of the vortex and ring spun cotton yarns and their knitted fabric properties was provided to evaluate the latent capability of the vortex spinning technology.The results show that the vortex yarn has better elongation,evenness and much less hairiness than the ring yarn.The vortex fabric is found to have better air permeability,bursting properties,and pilling resistance than the ring fabric,while the drapeability and abrasion resistance of the ring fabric are better than the vortex fabric.