Optimal Weight Distribution Research Articles

INCREASING THE TRACTION AND TRACTION CHARACTERISTICS OF THE ENERGY VEHICLE WHEN CARRYING OUT COMBINED SOIL PROCESSING OPERATIONS

The article is devoted to the study of methods and means that help to improve traction and traction characteristics of power vehicles, in particular tractors, when performing combined operations of soil treatment. The article analyzes the impact of weight distribution, tire pressure, and the use of special devices on the quality of tillage operations. It was established that the efficiency of combined tillage operations depends on the level of traction and traction characteristics of the power tool. To increase traction characteristics of the tractor, it is proposed to use mathematical methods of increasing tire pressure and optimal weight distribution on the axle. The article also describes special devices for increasing traction resistance, which help to provide better traction and increase traction characteristics. This article examines the influence of soil parameters on traction and traction characteristics of an energy vehicle during combined soil treatment operations. It was found that soil indicators, such as moisture, density and fractional composition, have a significant impact on the quality of soil processing operations and traction characteristics of the tractor. To solve this problem, methods of increasing traction and traction characteristics are proposed, such as a mathematical method of increasing tire pressure and a method of optimal weight distribution on the suspension. The use of special devices to increase traction resistance, which help to ensure better traction and improve traction characteristics, is also considered. The research conducted by the authors can be useful for tillage and tractor maintenance specialists who are engaged in optimizing the operation of energy equipment at agricultural enterprises.

Fatigue Detection Algorithm Based on Eye Multifeature Fusion

Fatigue driving is a critical cause of traffic accidents. Different from a single feature-based fatigue detection algorithm, this article uses the Dlib toolkit to mark facial feature points and presents a novel fatigue detection algorithm considering the eye’s multifeature and giving an optimal weight distribution for this fusion model, which intends not only to improve the reliability and error tolerance rate of detection but also to address the issue that traditional algorithms cannot make a balance between real time and accuracy at the same time. The eye’s multifeature fusion algorithm simultaneously detects the eye aspect ratio (EAR), the percentage of eyelid closure over the pupil (PERCLOS), the blink frequency (BF), and the pupil occlusion rate (POR). Afterward, the results are normalized to judge the driver’s fatigue level and give a corresponding warning. The testing results show that the accuracy of our proposed algorithm reaches 95%, exhibiting a solid potential in fatigue detection applications.

EVALUATION ANALYSIS OF THE RUNNING SYSTEM SOIL INTERACTION OF WHEELED AGRICULTURAL TRACTORS

The article provides an evaluative analysis of the wheeled agricultural tractor’s running systems soil interaction. A sample of more than 600 MFWD tractors of the world's leading manufacturers was subject to analysis. To determine the parameters of the maximum soil pressure, the value of the footprint gross flat plate area is applied, assuming that the tires are operated under conditions characterized by the speed index A6 with a significant torque for a long time. It is obtained the calculated function of the probability distribution of the maximum pressure on the soil of a sample of modern wheeled tractors with a fixed location of the centre of gravity (weight distribution). The designed arrangement of the centre of gravity of tractors by groups with the corresponding rolling circumference indexes difference ΔRCI =4...9 was analysed. It was established that for general and universal purpose tractors with ΔRCI = 4...6 the most common weight distribution coefficient is 0.40 or 0.44. For special (utility) tractors with ΔRCI = 7...9, the most common weight distribution coefficient is 0.45...0.46. An analysis of the maximum soil pressure in a wide range of the traction force of the tractor while maintaining a constant optimal weight distribution, which depends on the ratio of the footprint gross flat plate area of the front and rear tires, was carried out. The analysis showed that maintaining a constant optimal weight distribution during traction operations makes it possible to reduce the maximum pressure on the soil by 8...40 kPa. This makes it possible to increase the part of the territory of Ukraine, where modern wheeled tractors with single tires can be operated without violating agro-ecological requirements, by 14%.

Quantitative Assessment for the Impact of Novel Coronavirus Pneumonia Epidemic on Economic Viability in A Domestic Area

To combine the economic viability of urban areas with a quantitative condition that can characterize “epidemic” and “Pandemic” diseases, we use the factor analysis method to achieve index dimensionality reduction and subjective and objective integration method to achieve optimal weight distribution. We develop a judgment model by taking into account broad factors such as the epidemic situation, population, medical care, economy, and policy. On this basis, we chose 15 common infectious diseases as detection data and used the judgment model to obtain the specific quantitative judgment conditions of “spread, outbreak, epidemic, and pandemic.” The threshold for defining epidemics is between 3 and 5, and the threshold for defining pandemics is greater than 5.

On a Dirichlet Process Mixture Representation of Phase-Type Distributions

An explicit representation of phase-type distributions as an infinite mixture of Erlang distributions is introduced. The representation unveils a novel and useful connection between a class of Bayesian nonparametric mixture models and phase-type distributions. In particular, this sheds some light on two hot topics, estimation techniques for phase-type distributions, and the availability of closed-form expressions for some functionals related to Dirichlet process mixture models. The power of this connection is illustrated via a posterior inference algorithm to estimate phase-type distributions, avoiding some difficulties with the simulation of latent Markov jump processes, commonly encountered in phase-type Bayesian inference. On the other hand, closed-form expressions for functionals of Dirichlet process mixture models are illustrated with density and renewal function estimation, related to the optimal salmon weight distribution of an aquaculture study.

An Ensemble Classification Algorithm of Micro-Blog Sentiment Based on Feature Selection and Differential Evolution

In the face of massive texts, dimensionality reduction algorithm and efficient classification model have become the key steps for sentiment classification of microblogs. X2 statistics and TF-IDF statistics are commonly used dimension reduction methods. When applied to micro-blog sentiment analysis, traditional X2 statistics do not consider the probability of a certain sentiment word in a micro-blog text. TF-IDF weight measure ignores the synonyms in the text of micro-blog. Therefore, this paper proposes a NewChi-TF-IDF feature selection method combining form and semantics. In the classification stage, the generalization performance of single classifier is low. To enhance the generalization performance of Weibo sentiment classification, based on the existing ensemble strategy, differential evolution algorithm is introduced to assign different excitation functions to multiple weak classifiers to train the optimal weight distribution. Thus, the problem that the weight of weak classifier is difficult to determine is solved. Experimental results show that NewChi-TF-IDF feature selection method reduces the dimension, and the generalization ability of the proposed algorithm is enhanced, and the average F-score of the proposed algorithm is improved to a higher degree than that of Ada-All and Vote-All classifiers.

Further Investigation of Solvent Synergists for Improved Performance of Poly(N-vinylcaprolactam)-Based Kinetic Hydrate Inhibitors

Poly(N-vinylcaprolactam) (PVCap) and related copolymers have been used as kinetic hydrate inhibitors (KHIs) to combat gas hydrate formation in oil and gas field production flow lines. It is known that the addition of certain solvents to the KHI polymer can enhance its ability to hinder gas hydrate formation. In an earlier study, a wide range of alcohols, glycol ethers, and ketones were investigated as synergetic solvents with PVCap. In that study, an outstanding synergetic effect was achieved by 4-methyl-1-pentanol (iHexOl). This report builds on that study by investigating iHexOl in more detail as well as some newly synthesized solvents predicted by the first study to have good synergism. Both slow constant cooling (SCC) and isothermal KHI experiments were conducted in high-pressure steel rocking cells using a structure II-forming natural gas mixture. The KHI polymer concentration, solvent concentration, and mixed solvent systems were investigated. The solvent synergist water solubility, also in brines, and partitioning to the liquid hydrocarbon phase are shown to be important factors to consider for optimizing KHI performance. Further, it was observed that the optimal molecular weight distribution for the KHI polymer when used with a solvent synergist is not the same as the optimum distribution when using the polymer alone.

Facial micro-expressions as a soft biometric for person recognition

• Micro-expressions contain information pertinent to person recognition. • LBP-TOP is well suited to model appearance and motion changes in micro-expression. • Optimal weight distribution is important for traditional and soft biometric fusion. Soft biometrics, although not discriminant enough for person recognition provides additional information that aids traditional person recognition. Initially, attempts were made to integrate appearance-based facial soft biometrics, such as facial marks, skin color, and hair color/style, but more recently behavior-based facial soft biometrics, such as head dynamics, visual speech, and facial expressions have also been studied. Facial expressions are further classified as macro and micro-expressions and most of the existing studies using facial expressions as a soft biometric have focused on macro-expressions. Therefore, in this study, we investigate the utility of micro-expressions as a soft biometric for person recognition. The proposed system is based on the fusion of traditional facial features that model the facial appearance with soft biometric features that model the micro-expressions in an image sequence. We tested a texture-based traditional feature extraction technique, two motion-based soft biometric techniques, and several fusion methods at feature, rank, and decision level. The experiments were conducted on three commonly used micro-expression databases and exhibit an improvement of around 5% identification rate when soft biometric traits are fused with traditional face recognition at decision level.

Mechanical Devices for Mass Distribution Adjustment: Are They Really Convenient?

Since the introduction of four-wheel drive (4WD) and especially front wheel assist (FWA), many studies have been conducted on the optimal weight distribution between tractor front and rear axles because this influences traction efficiency. The aim of this paper is to evaluate the traction and efficiency advantages in the adoption of mechanical ballast position adjustment devices. The tested device is an extendable ballast holder mounted on the front three-point hitch of the tractor, able to displace the ballast up to 1 m away from its original position. An estimation of the fuel consumption during ploughing with the extendable ballast holder in different configurations was performed. Tractive performance was evaluated through drawbar tests, performed on loam soil with a 4WD tractor having a maximum engine power of 191 kW and a ballasted mass of 9590 kg. Results show that changing the tractor weight distribution over the range allowed by the extendable ballast holder produces limited effects in terms of tractive performance and fuel saving. The adoption of such devices is thus ineffective if other fundamental factors such as tyre pressure, choice of the front-to-rear wheel combination and lead of the front wheels are not considered during tractor setup.

Fragmental weight-conservation combining scheme for statistical signal transmissions under fast time-varying channels

Statistical Signal Transmission (SST) is a technique based on orthogonal frequency-division multiplexing (OFDM) and adopts cyclostationary features, which can transmit extra information without additional bandwidth. However, the more complicated environment in 5G communication systems, especially the fast time-varying scenarios, will dramatically degrade the performance of the SST. In this paper, we propose a fragmental weight-conservation combining (FWCC) scheme for SST, to overcome its performance degradation under fast time-varying channels. The proposed FWCC scheme consists of three phases: 1) incise the received OFDM stream into pieces; 2) endue different weights for fine and contaminated pieces, respectively; 3) combine cyclic autocorrelation function energies of all the pieces; and 4) compute the final feature and demodulate data of SST. Through these procedures above, the detection accuracy of SST will be theoretically refined under fast time-varying channels. Such an inference is confirmed through numerical results in this paper. It is demonstrated that the BER performance of proposed scheme outperforms that of the original scheme both in ideal channel estimation conditions and in imperfect channel estimation conditions. In addition, we also find the experiential optimal weight distribution strategy for the proposed FWCC scheme, which facilitates practical applications.

Exploring the formaldehyde reactivity of tannins with different molecular weight distributions: bayberry tannins and larch tannins

Abstract In recent years, tannin degradation has been used to obtain tannin materials with an optimal molecular weight distribution (MWD) for synthesizing tannin-formaldehyde (TF) resin with high performance, but the optimal MWD of tannins is still unknown. The excellent formaldehyde reactivity of tannins is the basis for the synthesis of high-performance TF resin. Based on the formaldehyde reactivity of tannins, bayberry tannins and larch tannins were used to explore the optimal MWD of tannins for TF resin synthesis. Progressive solvent precipitation (PSP) was used to obtain tannin fractions with different MWDs. The formaldehyde reactivity of tannins was determined using the modified Stiansy method combined with the standard curve method (GB/T 17657-2013). The bayberry tannin fraction [weight-average molecular weight (Mw) of acetylated tannin: 4115, mean degree of polymerization (mDP): 6.64] and the larch tannin fraction (Mw of acetylated tannin: 3906, mDP: 5.84) had the best formaldehyde reactivity. Furthermore, significant differences in the formaldehyde reactivity of condensed tannins (CTs) with different MWDs were observed. The obtained results can be used to purposefully degrade tannins to achieve an optimal MWD, which is beneficial for the production of TF adhesives with high performance.

AUV near-wall-following control based on adaptive disturbance observer

When detecting the wall crack, interferences caused by wall effect will significantly increase the difficulty of controlling AUV. This paper focuses on observing and compensating for interferences in the design of the controller. The optimal weight distribution algorithm is proposed to obtain the desired real-time optimal heading, which ensures that the AUV can achieve autonomous following of the wall by adjusting the heading. The backstepping sliding mode controller based on a slow time-varying adaptive disturbance observer (ADO) is proposed, which can effectively observe and compensate for the interference during AUV near-wall following. Results show that the tracking error of the proposed controller can be greatly reduced compared with the PID controller, and the tracking error is significantly reduced compared with the conventional sliding mode controller. The proposed controller can converge fast with small overshoot and stable control effect. The ADO provides strong robustness against interference, such as wall effect. Thus, AUVs can stably perform near-wall-following tasks and capture clear videos.

Neural network for prediction of hardness profiles for steel alloys after plasma nitriding

Plasma nitriding is a state-of-the-art thermochemical treatment, which is used by the processing industry for hardening of the surface-near material volumes of tools and components. An artificial neural network, particularly backpropagation neural network, has been developed to investigate the hardness behavior of different steel types according to various process parameters. Therefor eleven steels with different chemical compositions were plasma nitrated with different concentrations of nitrogen at various temperatures. The hardness profiles were studied with indentation measurement. The experimental data were used to train the neural network with the Levenberg-Marquardt algorithm. For an optimal training, weight distribution, hidden neurons and gradients of neuron activation functions were varied, to allow simulations of hardness profiles for the different types of steel with deviant nitriding parameters.

Collagen Hydrolysates of Skin Shavings Prepared by Enzymatic Hydrolysis as a Natural Flocculant and Their Flocculating Property.

A series of collagen hydrolysates (CHs) were prepared from pigskin shavings by using pepsin (PCH), trypsin (TCH), Alcalase (ACH), HCl (HCH), and NaOH (NCH). Their physicochemical properties, including degree of collagen hydrolysis, molecular weight distribution, electric charge, and microstructure, were investigated, and their flocculation performance was evaluated in a kaolin suspension, at varied pHs and concentrations. PCH exhibited high flocculation capability under acidic and neutral conditions, and its efficiency for removing suspended particles was approximately 80% at a concentration of 0.05g/L. TCH, ACH, HCH, and NCH showed almost no flocculation capability. The flocculation capability of PCH could be mainly due to a combination of optimal molecular weight distribution and electric charge. This study could provide an environment-friendly natural flocculant and also proposes a promising approach for the reuse of collagen wastes. Graphical Abstract ᅟ.

Winning Approach: Selection Criteria for Competitive Battery Powered Racing Vehicles

This paper presents a systematic approach for optimal selection of race discipline and race format to develop a battery powered racing vehicle that is competitive with internal combustion vehicles. The main limitation for battery powered vehicles is the mass of the battery that grows directly with race duration, and the break-even point is currently around 10 minutes. However, battery powered vehicles have other advantages such as indifference to altitude, superior traction control, and moldability of the drivetrain for aerodynamic advantage or for optimal weight distribution, making them highly competitive in certain disciplines such as land speed racing and hill climb.

Maximizing algebraic connectivity in interconnected networks.

Algebraic connectivity, the second eigenvalue of the Laplacian matrix, is a measure of node and link connectivity on networks. When studying interconnected networks it is useful to consider a multiplex model, where the component networks operate together with interlayer links among them. In order to have a well-connected multilayer structure, it is necessary to optimally design these interlayer links considering realistic constraints. In this work, we solve the problem of finding an optimal weight distribution for one-to-one interlayer links under budget constraint. We show that for the special multiplex configurations with identical layers, the uniform weight distribution is always optimal. On the other hand, when the two layers are arbitrary, increasing the budget reveals the existence of two different regimes. Up to a certain threshold budget, the second eigenvalue of the supra-Laplacian is simple, the optimal weight distribution is uniform, and the Fiedler vector is constant on each layer. Increasing the budget past the threshold, the optimal weight distribution can be nonuniform. The interesting consequence of this result is that there is no need to solve the optimization problem when the available budget is less than the threshold, which can be easily found analytically.

Strength calculations and optimal weight design of multilayer shell-shaped composite products under a set of loads

The stress-strain state of axisymmetric multilayer shells is analyzed using kinematic and static hypotheses that allow for the transverse shear stresses satisfying the necessary equations of state, continuity conditions at the boundaries between the layers and given boundary conditions. A numerical solution of the problem of the stress-strain state for a multilayer bar is compared with the Lekhnitskii solution (for a cantilever beam loaded by a concentrated force and moment) to asses the applicability of the employed bending equations of multilayer shells. It is shown that these solutions are in good agreement. The problem of the initial fracture of the shells considered is formulated using phenomenological strength criteria for each layer. A coordinate-wise descent method in the unit interval is proposed to solve weight optimization problems for multilayer shells of composite materials under combined loading. Regions of safe operating loads and the optimal weight distribution of layer thicknesses are determined for a multilayer bar acted upon by a uniformly distributed load and concentrated force.

DISSIPATIVE PARTICLE DYNAMICS SIMULATION STUDY ON CONTROLLING MOLECULAR WEIGHT DISTRIBUTION IN EMULSION POLYMERIZATION

The controlling factors on molecular weight distribution in emulsion polymerization are investigated using dissipative particle dynamics simulations. The propagation and bi-radical termination kinetic steps are taken into account in the simulations by coupling a Monte Carlo type reaction model. We find that monomer concentration can be very efficient on controlling molecular weight distribution and plays a decisive role on the formation of high molecular weight polymers. Increasing initiator concentration can effectively reduce the polymer molecular weight while increasing the polydispersity index. Moreover, increasing polymerization rate can slightly narrow the molecular weight distribution. We also find that, by suitably tuning the surfactant chain length, it may be possible to obtain an optimal molecular weight distribution in emulsion polymerization.

Random Weighting Method for Multisensor Data Fusion

This paper presents a new data fusion method by adopting random weighting estimation for optimal weighted fusion of multisensor observation data. This method adjusts in real time the weights of individual sensors according to variations in estimated sensor variances to obtain optimal weight distribution. Theories of random weighting estimation are established for optimal data fusion through optimal weighting distribution. Algorithms of random weighting estimation are developed to calculate sensor variances for determination of optimal random weighting factors. The fusion result in least mean square error is achieved directly from multisensor observation data, without requirement of any prior knowledge on unknown parameters. The mean square error estimated by the proposed method is not only smaller than from each individual sensor, but also smaller than by the mean of multisensor observation data.

Effect of the front and rear weight distribution ratio of a Formula car during maximum-speed cornering on a circuit

Because Formula cars are lighter than ordinary cars, the optimal settings for this type of car are thought to be different from those of a ordinary car. The front and rear weight distribution ratio of a vehicle is an important parameter that exerts a significant influence on critical cornering. The tendency of a ordinary car to under-steer during critical cornering is determined by the front and rear weight distribution ratio of the vehicle. Specifically, when the front of an ordinary FR (front-engine, rear wheel drive) vehicle is slightly heavier than the rear, the car tends to understeer during critical cornering. However, the optimal weight distribution ratio for critical cornering is not obvious for a formula car because of its lightness. This observation was investigated using a driving course similar to a real driving course to perform a maximum speed cornering simulations. It was found that a front to rear weight distribution ratio of 40:60 resulted in the fastest lap time. This ratio also gave the best results in the maximum-speed driving experiment performed using a driving simulator. Moreover, the maximum lateral acceleration during turning, the driving force, and the load movement of the inside and outside wheels was calculated using experimental driving force data and the concept of a tire friction circle. As a result, driving mechanics have been determined for a vehicle having a front/rear weight distribution ratio of 40:60 while traveling at maximum speed.