While spin-orbit interaction has been extensively studied,few investigations have reported on the interaction between orbital angular momenta(OAMs).In this work,we study a new type of orbit-orbit coupling between the ...
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While spin-orbit interaction has been extensively studied,few investigations have reported on the interaction between orbital angular momenta(OAMs).In this work,we study a new type of orbit-orbit coupling between the longitudinal OAM and the transverse OAM carried by a three-dimensional(3D)spatiotemporal optical vortex(STOV)in the process of tight *** 3D STOV possesses orthogonal OAMs in the x-y,t-x,and y-t planes,and is preconditioned to overcome the spatiotemporal astigmatism effect.x,y,and t are the axes in the spatiotemporal *** corresponding focused wavepacket is calculated by employing the Debye diffraction theory,showing that a phase singularity ring is generated by the interactions among the transverse and longitudinal vortices in the highly confined *** Fourier-transform decomposition of the Debye integral is employed to analyze the mechanism of the orbit-orbit *** is the first revelation of coupling between the longitudinal OAM and the transverse OAM,paving the way for potential applications in optical trapping,laser machining,nonlinear light-matter interactions,and more.
Experimental studies were conducted on two high-strength steel plate-frame structures with different truss spacings under various impact velocities to investigate the dynamic mechanical properties of hull plate-frame ...
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Experimental studies were conducted on two high-strength steel plate-frame structures with different truss spacings under various impact velocities to investigate the dynamic mechanical properties of hull plate-frame structures under drop weight *** results showed that decreasing the main beam spacing can effectively increase the structural stiffness,reduce the maximum deformation,and increase the damage ***,to simulate the impact tests accurately,static and dynamic tensile tests at different strain rates were carried out,and the Cowper-Symonds model parameters were fitted via experimental *** material properties obtained from the tensile tests were used as inputs for numerical simulations with the numerical results coincide with the experimental results.A systematic analysis and discussion were conducted on the effects of truss spacing and truss width on the dynamic response of the reinforced plates,and an optimal range for the ratio of truss spacing to truss width was *** addition,a mesh size sensitivity analysis for ship hull plate frame collision simulations was *** applicability of the EPS,MMC,and RTCL failure criteria in the simulation of plate-frame structures was investigated via finite element simulations of falling weight impact *** research findings provide a reference for ship hull structure design and resilience assessment.
The current study is defined by two main aims. An effective strategy for improving local search is to combine the Set Algebra-Based Heuristic Algorithm (SAHA) algorithm with the Nelder-Mead simplex method. The approac...
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This letter proposes a reliable transfer learning(RTL)method for pre-fault dynamic security assessment(DSA)in power systems to improve DSA performance in the presence of potentially related unknown *** takes individua...
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This letter proposes a reliable transfer learning(RTL)method for pre-fault dynamic security assessment(DSA)in power systems to improve DSA performance in the presence of potentially related unknown *** takes individual discrepancies into consideration and can handle unknown faults with incomplete *** experiment results demonstrate high DSA accuracy and computational efficiency of the proposed RTL *** analysis shows RTL can guarantee system performance.
Pinless friction stir spot welding(P-FSSW)was performed to manufacture Mg/steel lap *** tests for P-FSSW of Mg/steel were investigated,and the main factors affecting the properties of Mg/steel lap joints were *** shea...
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Pinless friction stir spot welding(P-FSSW)was performed to manufacture Mg/steel lap *** tests for P-FSSW of Mg/steel were investigated,and the main factors affecting the properties of Mg/steel lap joints were *** shear force of the Mg/steel lap joints gradually increased and then decreased as the welding time *** shear force was 5.3 ***-Al intermetallic compound(IMC)was formed at the Mg/steel interface near the steel side,and Mg-Al IMCs were formed at the Mg/steel interface near the Mg alloy ***/steel lap joint was transformed from an initial solid-state welding to fusion-brazing welding as the welding time *** hole defects were formed in Mg/steel solid-state welding joints,whereas hole defects appeared in Mg/steel fusion-brazing welding *** temperature field of Mg/steel lap joints was simulated to analyze hole defects generated during the welding *** defects can be eliminated by changing the spindle deflection angle,and the shear force *** spindle deflection can also lead to failure to form a stable *** defects were removed because the spindle deflection angle reduced the interfacial reaction temperature,and a solid-state welding joint was formed,which resulted in an absence of fusion-brazing welding hole formation.
Carbide dispersion reinforcing has been demonstrated to be an effective way of strengthening metal ma-trix ***,plagued by the nerve-wracking fact that the carbide particles tend to aggregate at the grain boundary of t...
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Carbide dispersion reinforcing has been demonstrated to be an effective way of strengthening metal ma-trix ***,plagued by the nerve-wracking fact that the carbide particles tend to aggregate at the grain boundary of the metal matrix,grow up,and form an incoherent interface with it,their im-provement in mechanical strength tends to be *** this study,spark plasma sintering(SPS)was used to prepare the bulk alloy Ni20Cr and its composites with different carbides including TiC,SiC,and *** leads to discharge and elevates temperature at the interface to melt the Ni20Cr alloy par-ticles *** cooled down,the alloy is heterogeneously solidified on the surface of the carbide and builds up a coherent interface with *** to the decomposition of Ti3SiC2 during sintering,it completely transformed into nanosized TiC particles,which are engulfed by the outer melted layer of Ni20Cr and well dispersed within the alloy *** comparison to the Ni20Cr alloy,the composite with merely 4 wt％Ti3SiC2 gains over three times enhancement in yield strength to 879 MPa,while keeping a moderate high elongation of 17.8％.Finite element analysis demonstrated that the combination of SPS and precursor MAX phase of Ti3SiC2,which results in the in-situ precipitation of coherent ultrafine TiC particles in alloy grains,plays the key role in getting a good balance between mechanical strength and ductility for the Ni20Cr matrix composites.
In recent years, mental health issues have profoundly impacted individuals’ well-being, necessitating prompt identification and intervention. Existing approaches grapple with the complex nature of mental health, faci...
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In recent years, mental health issues have profoundly impacted individuals’ well-being, necessitating prompt identification and intervention. Existing approaches grapple with the complex nature of mental health, facing challenges like task interference, limited adaptability, and difficulty in capturing nuanced linguistic expressions indicative of various conditions. In response to these challenges, our research presents three novel models employing multi-task learning (MTL) to understand mental health behaviors comprehensively. These models encompass soft-parameter sharing-based long short-term memory with attention mechanism (SPS-LSTM-AM), SPS-based bidirectional gated neural networks with self-head attention mechanism (SPS-BiGRU-SAM), and SPS-based bidirectional neural network with multi-head attention mechanism (SPS-BNN-MHAM). Our models address diverse tasks, including detecting disorders such as bipolar disorder, insomnia, obsessive-compulsive disorder, and panic in psychiatric texts, alongside classifying suicide or non-suicide-related texts on social media as auxiliary tasks. Emotion detection in suicide notes, covering emotions of abuse, blame, and sorrow, serves as the main task. We observe significant performance enhancement in the primary task by incorporating auxiliary tasks. Advanced encoder-building techniques, including auto-regressive-based permutation and enhanced permutation language modeling, are recommended for effectively capturing mental health contexts’ subtleties, semantic nuances, and syntactic structures. We present the shared feature extractor called shared auto-regressive for language modeling (S-ARLM) to capture high-level representations that are useful across tasks. Additionally, we recommend soft-parameter sharing (SPS) subtypes-fully sharing, partial sharing, and independent layer-to minimize tight coupling and enhance adaptability. Our models exhibit outstanding performance across various datasets, achieving accuracies of 96.9%, 97.
Carbon nanotubes(CNTs)reinforced copper(CNTs/Cu)is one of the most promising and extensively researched materials for replacing traditional Cu-based materials in high-load and high-current applications,particularly wi...
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Carbon nanotubes(CNTs)reinforced copper(CNTs/Cu)is one of the most promising and extensively researched materials for replacing traditional Cu-based materials in high-load and high-current applications,particularly within the aerospace *** carbon nanotubes(aCNTs)are a type of carbon nanotubes characterized by the presence of mesopores distributed across their amorphous sidewalls,facilitating connectivity between the hollow core and the external ***,we propose utilizing aCNTs as a reinforcing agent for *** mesoporous structure of aCNTs facilitates the interpenetration of Cu into the aCNTs,thereby maintaining the continuity of the matrix *** results demonstrate that Cu effectively penetrates the mesoporous sidewalls of *** pure Cu and aCNTs-reinforced Cu exhibit comparable electrical conductivity,while the hardness of the aCNTs/Cu composite is significantly ***,both the density and porosity of aCNTs/Cu are lower than those of pure Cu,and the introduction of aCNTs helps to reduce the sintering temperature.
In this study, we utilize a recently proposed non-parametric metaheuristic algorithm known as geometric mean optimization (GMO) to adjust the hidden layer input weights and bias of six ANN variants, namely PSNN, SPNN,...
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Communication between people with disabilities and people who do not understand sign language is a growing social need and can be a tedious *** of the main functions of sign language is to communicate with each other ...
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Communication between people with disabilities and people who do not understand sign language is a growing social need and can be a tedious *** of the main functions of sign language is to communicate with each other through hand *** of hand gestures has become an important challenge for the recognition of sign *** are many existing models that can produce a good accuracy,but if the model test with rotated or translated images,they may face some difficulties to make good performance *** resolve these challenges of hand gesture recognition,we proposed a Rotation,Translation and Scale-invariant sign word recognition system using a convolu-tional neural network(CNN).We have followed three steps in our work:rotated,translated and scaled(RTS)version dataset generation,gesture segmentation,and sign word ***,we have enlarged a benchmark dataset of 20 sign words by making different amounts of Rotation,Translation and Scale of the ori-ginal images to create the RTS version *** we have applied the gesture segmentation *** segmentation consists of three levels,i)Otsu Thresholding with YCbCr,ii)Morphological analysis:dilation through opening morphology and iii)Watershed ***,our designed CNN model has been trained to classify the hand gesture as well as the sign *** model has been evaluated using the twenty sign word dataset,five sign word dataset and the RTS version of these *** achieved 99.30%accuracy from the twenty sign word dataset evaluation,99.10%accuracy from the RTS version of the twenty sign word evolution,100%accuracy from thefive sign word dataset evaluation,and 98.00%accuracy from the RTS versionfive sign word dataset ***,the influence of our model exists in competitive results with state-of-the-art methods in sign word recognition.
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