Digital Twin for Human-Robot Interactive Welding and Welder Behavior Analysis

This paper presents an innovative investigation on prototyping a digital twin(DT)as the platform for human-robot interactive welding and welder behavior analysis.This humanrobot interaction(HRI)working style helps to enhance human users'operational productivity and comfort;while data-driven welder behavior analysis benefits to further novice welder training.This HRI system includes three modules:1)a human user who demonstrates the welding operations offsite with her/his operations recorded by the motion-tracked handles;2)a robot that executes the demonstrated welding operations to complete the physical welding tasks onsite;3)a DT system that is developed based on virtual reality(VR)as a digital replica of the physical human-robot interactive welding environment.The DT system bridges a human user and robot through a bi-directional information flow:a)transmitting demonstrated welding operations in VR to the robot in the physical environment;b)displaying the physical welding scenes to human users in VR.Compared to existing DT systems reported in the literatures,the developed one provides better capability in engaging human users in interacting with welding scenes,through an augmented VR.To verify the effectiveness,six welders,skilled with certain manual welding training and unskilled without any training,tested the system by completing the same welding job;three skilled welders produce satisfied welded workpieces,while the other three unskilled do not.A data-driven approach as a combination of fast Fourier transform(FFT),principal component analysis(PCA),and support vector machine(SVM)is developed to analyze their behaviors.Given an operation sequence,i.e.,motion speed sequence of the welding torch,frequency features are firstly extracted by FFT and then reduced in dimension through PCA,which are finally routed into SVM for classification.The trained model demonstrates a 94.44%classification accuracy in the testing dataset.The successful pattern recognition in skilled welder operations should benefit to accelerate novice welder training.

“Do Big Hands Guide Small Hands?”or“do Small Hands Guide Big Hands”:The intergenerational interactions in environmental behaviors and family influencing factors

Families'large pollution and energy consumption cannot be underestimated.In order to realize and internalize environmental awareness as a social consensus,it is imperative for every member of a household to be involved in transforming everyday behavior.Intergenerational interactions are of paramount importance.Accordingly,the focus of this study was on parent-adolescent interactions,their reciprocal impact on environmental behaviors,and the factors that have an influence on these processes.Questionnaires were employed to collect information of 684 families in 10 districts of Jinan,the capital of Shandong Province.Subsequently,interviews were conducted with 15 of these families to comprehend the tangible reasons underlying intergenerational interactions in environmental behaviors.First,a paired sample T-test was employed to compare the frequency of these interactions.The data showed that while the T values were positive in all eight compared groups,there were significant differences in seven of them.These results suggest that the impact of intergenerational interactions on environmental behaviors is not symmetrical:parents'instructions are far more frequent than adolescents'back-feeding of ecological notions.The interviews revealed that this phenomenon was generated primarily by unequal experiences between parents and adolescents because the latter do not participate in housework and family projects.Furthermore,the traditional concept of intergenerational order appears to be permanent.Second,two linear regression models,a Parent-to-Adolescent model and an Adolescent-to-Parent model that encompassed several factors including family structure,intergenerational relationships,living environment,and families'social class were developed.Among these factors,the intergenerational relationship variable played a particularly significant role:the more equal and open-minded dialogs are incorporated into parent-adolescent communication,the more favorable interactions may occur for development of their environmental behaviors.Thus,when an environmental education system with families is constructed,it is imperative to promote a parent's ecological awareness with the help of grass-roots organizations by means of reasonable rewards and punishments to redress their former behaviors so as to let Big Hands Guide Small Hands.It is also crucial to enhance a more equal intergenerational relationship through parents'schooling or other relevant services so as to create a favorable atmosphere for Small Hands Guide Big Hands.

The Influence of Interactive Control on Subsidiary Performance: A Mediating Role of Subsidiary Managers’ Strategic Behavior

Under the principal-agent relationship, there are two major factors that directly affect subsidiary strategy’s implementation and performance—enterprise groups’ internal interactive control and subsidiary managers’ strategic behavior. Prior research showed that the parent companies hope their subsidiary managers to be obedient and active, i.e. to keep a high degree of strategic identity and subsidiary initiative. We build and analyze a model to test the mediating role of strategic identity and subsidiary initiative based on data collected from Chinese groups. The results show that interactive control, strategic identity and subsidiary initiative all could improve subsidiary performance, furthermore, subsidiary initiative is a mediator between decision-making decentralization and subsidiary performance, and also a mediator between horizontal communication and subsidiary performance, the mediating role of strategic identity is not tested, but vertical communication can improve strategic identity. In the conclusions, we provide guidance on how parent companies to choose excellent subsidiary managers, and then how to develop a suite interactive control system.

High-Order Soliton Solutions and Hybrid Behavior for the (2 + 1)-Dimensional Konopelchenko-Dubrovsky Equations

In this paper, the evolutionary behavior of N-solitons for a (2 + 1)-dimensional Konopelchenko-Dubrovsky equations is studied by using the Hirota bilinear method and the long wave limit method. Based on the N-soliton solution, we first study the evolution from N-soliton to T-order (T=1,2) breather wave solutions via the paired-complexification of parameters, and then we get the N-order rational solutions, M-order (M=1,2) lump solutions, and the hybrid behavior between a variety of different types of solitons combined with the parameter limit technique and the paired-complexification of parameters. Meanwhile, we also provide a large number of three-dimensional figures in order to better show the degeneration of the N-soliton and the interaction behavior between different N-solitons.

Elastic Behaviors of Adsorbed Protein-like Chains

Elastic behaviors of protein-like chains are investigated by Pruned-Enriched-Rosenbluth method and modified orientation-dependent monomer-monomer interactions model. The protein-like chain is pulled away from the attractive surface slowly with elastic force acting on it. Strong adsorption interaction and no adsorption interaction are both considered. We calculate the characteristic ratio and shape factor of protein-like chains in the process of elongation. The conformation change of the protein-like chain is well depicted. The shape of chain changes from “rod” to “sphere” at the beginning of elongation. Then, the shape changes from “sphere” to “rod”. In the end, the shape becomes a “sphere” as the chain leaves away from the surface. In the meantime, we discuss average Helmoholtz free energy per bond, average energy per bond, average adsorbed energy per bond, average α-helical energy per bond, average β-sheet energy per bond and average contact energy per bond. On the other hand, elastic force is also studied. It is found that elastic force has a long plateau during the tensile elongation when there exists adsorption interaction. This result is consistent with SMFS experiment of general polymers. Energy contribution to elastic force and contact energy contribution to elastic force are both discussed. These investigations can provide some insights into the elastic behaviors of adsorbed protein chains.

Environment and Human Behaviors——Taking “The Acorn Gatherer” as a Case Study

Human living environment interacts with human behaviors.Environment to some degree determines human behaviors which in return reshape and sustain the dynamic environment.Taking Richard Jefferies' The Acorn Gatherer as a case study,this paper makes an argument that the behaviors of the villagers in the story can be more adequately interpreted in view of the backward countryside environment,and the same is true with the author Richard Jefferies' non-interference in the omniscient third-person point of view in writing the story.It is Richard Jefferies' family environment that makes up his viewpoint of writing,reflecting his critical loving of the countryside,where lives boom and conventions are extremely followed.

Unsteady Flow and Structural Behaviors of Centrifugal Pump under Cavitation Conditions

Cavitation has a significant e ect on the flow fields and structural behaviors of a centrifugal pump. In this study, the unsteady flow and structural behaviors of a centrifugal pump are investigated numerically under di erent cavitation conditions. A strong two-way coupling fluid-structure interaction simulation is applied to obtain interior views of the e ects of cavitating bubbles on the flow and structural dynamics of a pump. The renormalization-group k-ε turbulence model and the Zwart–Gerbe–Belamri cavitation model are solved for the fluid side, while a transient structural dynamic analysis is employed for the structure side. The di erent cavitation states are mapped in the head-net positive suction head(H-NPSH) curves and flow field features inside the impeller are fully revealed. Results indicate that cavitating bubbles grow and expand rapidly with decreasing NPSH. In addition, the pressure fluctuations, both in the impeller and volute, are quantitatively analyzed and associated with the cavitation states. It is shown that influence of the cavitation on the flow field is critical, specifically in the super-cavitation state. The e ect of cavitation on the unsteady radial force and blade loads is also discussed. The results indicate that the averaged radial force increased from 8.5 N to 54.4 N in the transition progress from an onset cavitation state to a super-cavitation state. Furthermore, the structural behaviors, including blade deformation, stress, and natural frequencies, corresponding to the cavitation states are discussed. A large volume of cavitating bubbles weakens the fluid forces on the blade and decreases the natural frequencies of the rotor system. This study could enhance the understanding of the e ects of cavitation on pump flow and structural behaviors.

Simulation study on cooperation behaviors and crowd dynamics in pedestrian evacuation

Pedestrian evacuation is actually a process of behavioral evolution. Interaction behaviors between pedestrians affect not only the evolution of their cooperation strategy, but also their evacuation paths-scheduling and dynamics features. The existence of interaction behaviors and cooperation evolution is therefore critical for pedestrian evacuation. To address this issue, an extended cellular automaton(CA) evacuation model considering the effects of interaction behaviors and cooperation evolution is proposed here. The influence mechanism of the environment factor and interaction behaviors between neighbors on the decision-making of one pedestrian to path scheduling is focused. Average payoffs interacting with neighbors are used to represent the competitive ability of one pedestrian, aiming to solve the conflicts when more than one pedestrian competes for the same position based on a new method. Influences of interaction behaviors, the panic degree and the conflict cost on the evacuation dynamics and cooperation evolution of pedestrians are discussed. Simulation results of the room evacuation show that the interaction behaviors between pedestrians to a certain extent are beneficial to the evacuation efficiency and the formation of cooperation behaviors as well. The increase of conflict cost prolongs the evacuation time. Panic emotions of pedestrians are bad for cooperation behaviors of the crowd and have complex effects on evacuation time. A new self-organization effect is also presented.

Study of Cell Behaviors on Anodized TiO_2 Nanotube Arrays with Coexisting Multi-Size Diameters

It has been revealed that the different morphologies of anodized TiO_2 nanotubes, especially nanotube diameters, triggered different cell behaviors. However, the influence of TiO_2 nanotubes with coexisting multi-size diameters on cell behaviors is seldom reported. In this work, coexisting four-diameter TiO_2 nanotube samples, namely,one single substrate with the integration of four different nanotube diameters(60, 150, 250, and 350 nm), were prepared by repeated anodization. The boundaries between two different diameter regions show well-organized structure without obvious difference in height. The adhesion behaviors of MC3T3-E1 cells on the coexisting fourdiameter TiO_2 nanotube arrays were investigated. The results exhibit a significant difference of cell density between smaller diameters(60 and 150 nm) and larger diameters(250 and 350 nm) within 24 h incubation with the coexistence of different diameters, which is totally different from that on the single-diameter TiO_2 nanotube arrays. The coexistence of four different diameters does not change greatly the cell morphologies compared with the singlediameter nanotubes. The findings in this work are expected to offer further understanding of the interaction between cells and materials.

Host-guest supramolecular interaction behavior at the interface between anode and electrolyte for long life Zn anode

The hydrogen evolution reaction (HER) and dendrite growth associated with Zn anode have become the main bottlenecks for the further development of zinc ion batteries (ZIBs).In this work,the electrochemical activity of H_(3)O^(+) is inhibited by the supramolecular host–guest complex composed of H_(3)O^(+) as guest and 18-crown-6 as host.The even Zn plating is induced by the host–guest complex electrostatic shielding layer on Zn anode,as detected by in-situ optical microscopy.The lamellar Zn is plated which profits from the improved Zn plating behavior.Density functional theory (DFT) calculation presents the stable structure of complex.The less produced H_(2) content is monitored online by a mass spectrometer during Zn plating/stripping,which indicates HER can be hampered by the host–guest behavior.Thus,the ZIBs with long life and high Coulombic efficiency are achieved via introducing 18-crown-6.The proposed host–guest supramolecular interaction is expected to facilitate the furthermore development of Zn batteries.

Nanoindentation Characterization of Creep-fatigue Interaction on Local Creep Behavior of P92 Steel Welded Joint

In modern fossil and nuclear power plants,the components are subjected to creep,fatigue,and creep-fatigue(CF)due to frequent start-up and shut-down operations at high temperatures.The CF interaction on the in-service P92 steel welded joint was investigated by strain-controlled CF tests with different dwell times of 30,120,300,600 and 900 s at 650℃.Based on the observations of the fracture surface by scanning electron microscope(SEM),the character-istic microstructure of fatigue-induced damage was found for the CF specimens with short dwell times(30 and 120 s).The hardness,elastic modulus and creep deformation near the fracture edges of four typical CF specimens with 30,120,600 and 900 s dwell times were measured by nanoindentation.Compared to specimens with post-weld heat treatment(PWHT),lower hardness and creep strength were found for all CF specimens.In addition,significant reduc-tions in hardness,elastic modulus,and creep strength were measured near the fracture edges for the CF specimens with short dwell times compared to the PWHT specimens.Compared to PWHT specimens(0.007),the increased strain rate sensitivities(SRS)of 0.010 to 0.17 were estimated from secondary creep.The increased values of SRS indicate that the room temperature creeps behavior is strongly affected by the decrease in dislocation density after the CF tests.

Modelling of vehicle interaction behavior during discretionary lane-changing preparation process on freeway

In order to increase the accuracy of microscopic traffic flow simulation,two acceleration models are presented to simulate car-following behaviors of the lane-changing vehicle and following putative vehicle during the discretionary lanechanging preparation( DLCP) process, respectively. The proposed acceleration models can reflect vehicle interaction characteristics. Samples used for describing the starting point and the ending point of DLCP are extracted from a real NGSIM vehicle trajectory data set. The acceleration model for a lanechanging vehicle is supposed to be a linear acceleration model.The acceleration model for the following putative vehicle is constructed by referring to the optimal velocity model,in which optimal velocity is defined as a linear function of the velocity of putative leading vehicle. Similar calibration,a hypothesis test and parameter sensitivity analysis were conducted on the acceleration model of the lane-changing vehicle and following putative vehicle,respectively. The validation results of the two proposed models suggest that the training and testing errors are acceptable compared with similar works on calibrations for car following models. The parameter sensitivity analysis shows that the subtle observed error does not lead to severe variations of car-following behaviors of the lane-changing vehicle and following putative vehicle.

Effect of Substrate-Water Interaction on the Wetting Behavior in Water-Oil and Substrate-Water-Oil Systems

The effects of the substrate-water interaction on the wetting behavior in water-oil and surfactant-water-oil systems confined by one substrate which has the preferential interaction to one species of particles have been investigated by using the free energy analysis and discontinuous molecular dynamic simulations. As the preferential interaction between the substrate and water particles varies from small repulsion to large attraction, the partial drying, partial wetting and complete wetting state are observed in sequence. In addition, the wetting behavior of surfactant aqueous solution on the substrate is not only dependent on the interaction, but also limited by the maximum equilibrium concentration of surfactants at the interface.

Transcriptome Profile Based on Protein-Protein Interaction Networks Provides a Set of Core Genes for Understanding the Metabolic Mechanisms of the Egg-Protecting Behavior in Amphioctopus fangsiao

Marine organisms cannot grow and reproduce without proper metabolic regulation.Within a metabolic network,problems with a given link will affect the normal life activities of the organism.Many metabolic mechanisms associated with behaviors of Am-phioctopus fangsiao are still unclear.Moreover,as a factor affecting the normal growth of A.fangsiao,egg protection has rarely been considered in previous behavioral studies.In this research,we analyzed the transcriptome profile of gene expression in A.fangsiao egg-unprotected larvae and egg-protected larvae,and identified 818 differentially expressed genes(DEGs).We used GO and KEGG enrichment analyses to search for metabolism-related DEGs.Protein-protein interaction networks were constructed to examine the interactions between metabolism-related genes.Twenty hub genes with multiple protein-protein interaction relationships or that were involved in multiple KEGG signaling pathways were obtained and verified by quantitative RT-PCR.We first studied the effects of egg protection on the metabolism of A.fangsiao larvae by means of protein-protein interaction networks,and the results provide va-luable gene resources for understanding the metabolism of invertebrate larvae.The data serve as a foundation for further research on the egg-protecting behavior of invertebrates.

Click-Through Rate Prediction Network Based on User Behavior Sequences and Feature Interactions

In recent years,deep learning has been widely applied in the fields of recommendation systems and click-through rate(CTR)prediction,and thus recommendation models incorporating deep learning have emerged.In addition,the design and implementation of recommendation models using information related to user behavior sequences is an important direction of current research in recommendation systems,and models calculate the likelihood of users clicking on target items based on their behavior sequence information.In order to explore the relationship between features,this paper improves and optimizes on the basis of deep interest network(DIN)proposed by Ali’s team.Based on the user behavioral sequences information,the attentional factorization machine(AFM)is integrated to obtain richer and more accurate behavioral sequence information.In addition,this paper designs a new way of calculating attention weights,which uses the relationship between the cosine similarity of any two vectors and the absolute value of their modal length difference to measure their relevance degree.Thus,a novel deep learning CTR prediction mode is proposed,that is,the CTR prediction network based on user behavior sequence and feature interactions deep interest and machines network(DIMN).We conduct extensive comparison experiments on three public datasets and one private music dataset,which are more recognized in the industry,and the results show that the DIMN obtains a better performance compared with the classical CTR prediction model.

Dynamic magnetic behavior of the mixed spin (2, 5/2) Ising system with antiferromagnetic/antiferromagnetic interactions on a bilayer square lattice

Using the mean-field theory and Glauber-type stochastic dynamics, we study the dynamic magnetic properties of the mixed spin （2, 5/2） Ising system for the antiferromagnetic/antiferromagnetic （AFM/AFM） interactions on the bilayer square lattice under a time varying （sinusoidal） magnetic field. The time dependence of average magnetizations and the thermal variation of the dynamic magnetizations are examined to calculate the dynamic phase diagrams. The dynamic phase diagrams are presented in the reduced temperature and magnetic field amplitude plane and the effects of interlayer coupling interaction on the critical behavior of the system are investigated. We also investigate the influence of the frequency and find that the system displays richer dynamic critical behavior for higher values of frequency than that of the lower values of it. We perform a comparison with the ferromagnetic/ferromagnetic （FM/FM） and AFM/FM interactions in order to see the effects of AFM/AFM interaction and observe that the system displays richer and more interesting dynamic critical behaviors for the AFM/AFM interaction than those for the FM/FM and AFM/FM interactions.

Means of Choice for Interactive Management of Dynamic Geometry Problems Based on Instrumented Behaviour

Our paper presents a project that involves two research questions: does the choice of a related problem by the tutorial system allow the problem solving process which is blocked for the student to be restarted? What information about learning do related problems returned by the system provide us? We answer the first question according to the didactic engineering, whose mode of validation is internal and based on the confrontation between an a priori analysis and an a posteriori analysis that relies on data from experiments in schools. We consider the student as a subject whose adaptation processes are conditioned by the problem and the possible interactions with the computer environment, and also by his knowledge, usually implicit, of the institutional norms that condition his relationship with geometry. Choosing a set of good problems within the system is therefore an essential element of the learning model. Since the source of a problem depends on the student’s actions with the computer tool, it is necessary to wait and see what are the related to problems that are returned to him before being able to identify patterns and assess the learning. With the simultaneity of collecting and analysing interactions in each class, we answer the second question according to a grounded theory analysis. By approaching the problems posed by the system and the designs in play at learning blockages, our analysis links the characteristics of problems to the design components in order to theorize on the decisional, epistemological, representational, didactic and instrumental aspects of the subject-milieu system in interaction.

A Study on the Path Mechanism of Para-social Interaction and Place Attachment on Film-Induced Tourists’Behavioral Intention

Under the influence of celebrity effect and para-social interaction,film is increasingly able to induce viewers’willingness to travel.Based on the theory of para-social interaction and the factors of place attachment,this study constructs a model of the influence mechanism of film-induced tourists’behavioral intention and puts relevant hypotheses.Taking the film A Little Red Flower as an example,the empirical test is carried out by using structural equation model(SEM).The results show that:(1)Film-induced tourists’emotional involvement has a significant positive impact on tourism behavioral involvement,but has no direct and significant impact on place dependence and place identity.(2)Film-induced tourists’behavioral involvement has a significant positive impact on place dependence and place identity.(3)Both place dependence and place identity of film-induced tourists have significant positive impact on tourism behavioral intention.Therefore,film tourism destinations should show the unique local conditions and customs according to the preference of fans and audiences,with the help of the popularity of film,so as to improve their tourism behavior intention.

A Simplified Method for Estimating the Initial Stiffness of Monopile-Soil Interaction Under Lateral Loads in Offshore Wind Turbine Systems

The interface mechanical behavior of a monopile is an important component of the overall offshore wind turbine structure design.Understanding the soil-structure interaction,particularly the initial soil-structure stiffness,has a significant impact on the study of natural frequency and dynamic response of the monopile.In this paper,a simplified method for estimating the interface mechanical behavior of monopiles under initial lateral loads is proposed.Depending on the principle of minimum potential energy and virtual work theory,the functions of soil reaction components at the interface of monopiles are derived;MATLAB programming has been used to simplify the functions of the initial stiffness by fitting a large number of examples;then the functions are validated against the field test data and FDM results.This method can modify the modulus of the subgrade reaction in the p-y curve method for the monopile-supported offshore wind turbine system.

Behavior of Delivery Robot in Human-Robot Collaborative Spaces During Navigation

Navigation is an essential skill for robots.It becomes a cumbersome task for the robot in a human-populated environment,and Industry 5.0 is an emerging trend that focuses on the interaction between humans and robots.Robot behavior in a social setting is the key to human acceptance while ensuring human comfort and safety.With the advancement in robotics technology,the true use cases of robots in the tourism and hospitality industry are expanding in number.There are very few experimental studies focusing on how people perceive the navigation behavior of a delivery robot.A robotic platform named“PI”has been designed,which incorporates proximity and vision sensors.The robot utilizes a real-time object recognition algorithm based on the You Only Look Once(YOLO)algorithm to detect objects and humans during navigation.This study is aimed towards evaluating human experience,for which we conducted a study among 36 participants to explore the perceived social presence,role,and perception of a delivery robot exhibiting different behavior conditions while navigating in a hotel corridor.The participants’responses were collected and compared for different behavior conditions demonstrated by the robot and results show that humans prefer an assistant role of a robot enabled with audio and visual aids exhibiting social behavior.Further,this study can be useful for developers to gain insight into the expected behavior of a delivery robot.