Coupled Analysis Research Articles

Direct coupling analysis and the attention mechanism

Proteins are involved in nearly all cellular functions, encompassing roles in transport, signaling, enzymatic activity, and more. Their functionalities crucially depend on their complex three-dimensional arrangement. For this reason, being able to predict their structure from the amino acid sequence has been and still is a phenomenal computational challenge that the introduction of AlphaFold solved with unprecedented accuracy. However, the inherent complexity of AlphaFold’s architectures makes it challenging to understand the rules that ultimately shape the protein’s predicted structure. This study investigates a single-layer unsupervised model based on the attention mechanism. More precisely, we explore a Direct Coupling Analysis (DCA) method that mimics the attention mechanism of several popular Transformer architectures, such as AlphaFold itself. The model’s parameters, notably fewer than those in standard DCA-based algorithms, can be directly used for extracting structural determinants such as the contact map of the protein family under study. Additionally, the functional form of the energy function of the model enables us to deploy a multi-family learning strategy, allowing us to effectively integrate information across multiple protein families, whereas standard DCA algorithms are typically limited to single protein families. Finally, we implemented a generative version of the model using an autoregressive architecture, capable of efficiently generating new proteins in silico.

Probabilistic and FEM hydro-mechanical coupling analysis of rainfall-induced slope instability

The random field theory coupled with a FEM hydro-mechanical model was employed to analyse slope responses under rainfall, with a particular focus on post-rainfall behaviour. This study uniquely analysed the heterogeneity of soil strength and permeability through the application of random field theory, providing a novel perspective on its impact on slope stability. Numerical modelling under varying rainfall intensities revealed that the factor of safety (FoS) decreased with prolonged rainfall, particularly at higher intensities. Post-rainfall behaviour varied for different rainfall events, that gentle and moderate rainfalls led to a gradual decline in FoS due to water infiltration, while heavy rainfall allowed recovery through drainage, and extremely heavy rainfall triggered immediate failure. A novel finding is that post-rainfall water seepage can govern slope stability under extreme rainfall conditions. At failure, the surface layer of a fully saturated slope lost clay suction and exhibited concentrated plastic shear strain at its base. Weak zones with interconnected high-permeability channels significantly influenced slope stability by facilitating water infiltration. Probabilistic analysis further showed that the FoS at the end of simulations typically ranged from 1.1 to 1.4, with a recommended 5th percentile value of 1.1 for slope designs.

Magnon-magnon coupling in noncollinear synthetic antiferromagnets

Abstract We report a theoretical analysis of magnon-magnon coupling in a noncollinear magnetic sandwiched structure with interlayer exchange interaction, which consists of two ferromagnetic layers with perpendicular and in-plane magnetic anisotropy, respectively. Based on the Landau-Lifshitz equation, the spin wave dispersion is derived, and then the frequency gap is observed due to the magnon-magnon coupling effect induced by symmetry-breaking. The influence of saturation magnetization, exchange coupling interaction, perpendicular magnetic anisotropy, and wave vector on the coupling strength is studied in detail. We find that the coupling strength is strongly dependent on the saturation magnetization and a small saturation magnetization can lead to strong coupling strength. By selecting the appropriate magnetic materials, ultra-strong coupling regime can be achieved. The precession information in time-domain is solved and the alternate change of the precession components in two ferromagnetic layers implies the exchange of energy and information.

Cortical and subcortical activities during food rewards versus social interaction in rats

Balancing food foraging with social interaction is crucial for survival and reproduction in many species of mammals. We wanted to investigate the reward preferences in adult male rats by allowing them to lever-press for both food and social rewards (interaction with another rat), while their performance and electrophysiological activities were recorded. Local field potentials (LFPs) were analyzed across five neuroanatomical regions involved in reward processing, decision-making, and social behavior. Despite ad libitum food availability, rats consistently prioritized food. LFP analysis revealed a decrease in nucleus accumbens (NAc) spectral power following social interaction, accompanied by specific alterations in delta and theta bands within the medial prefrontal cortex (mPFC). The spectral power of LFPs delta and/or theta bands were different for the five selected regions following food reward vs. social interactions. Cross-frequency coupling analysis provided further insights, demonstrating dynamic changes in theta-to-gamma coupling during both food and social rewards, with distinct roles for slow- and fast-gamma frequencies. These findings shed light on the intricate neural processes underlying reward preferences and/or decision-making choices, highlighting the NAc’s potential role in social reward processing, and the mPFC’s involvement in modulating theta–gamma rhythms during reward-related decision-making.

Coupled analysis of ocean-atmosphere interaction using A2CDOSE and SCHISM for radioactive dispersion following a north pacific nuclear incident

Abstract The Fukushima disaster highlighted the critical importance of a comprehensive emergency response plan for severe nuclear power plant (NPP) accidents. In response to this need, Taiwan’s National Atomic Research Institute (NARI) collaborated with the Central Weather Administration (CWA) to develop an urgent radiological dose evaluation system known as “A2CDOSE.” This system is designed to assess projected radiation doses over eight days following a nuclear incident, aiding in informed decision-making. Considering enhancing the multi-consequence analysis via nuclear material transport, this study connects the settings of ocean radiation contribution in series to develop a multi-sequence, multi-batch method called the ocean-atmosphere coupled analysis of radioactive substances with ocean dispersion code SCHISM. This Year’s (2024) hypothetical cesium-137 release case from the nuclear power plant was used to conduct a technical feasibility test. This method can serve as a reference for evaluating the optimal radiation detection routes for the affected maritime areas during future nuclear safety events, simulating the short-to mid-term effects of radioactive substance releases.

Evolution of takaful research: a bibliometric analysis

Purpose The purpose of this paper is to present a bibliometric overview of research published in takaful by identifying the most relevant research in this field and the newest trends according to the information in the Scopus database. Several classifications are made, including analyzing the most productive authors, the most influential journals, the collaboration between countries and the highly cited articles. Design/methodology/approach This paper collected data from Scopus databases from 1989 to 2023. The Bibliometrics, R-Studio, VOSviewer and Excel software were used to analyze the collected data. Bibliographic analysis was applied, consisting of co-authorship, cartographic, co-citation and coupling analyses. Findings This paper found that the publication and citation of takaful are increasing over time, contributing to significant progress in impact and visibility. Salman, Ghazali, Hassan and Mamat are the most productive authors. Malaysia is the most cited country, followed by the UK, while institutions from Malaysia are leading the publication of takaful literature. In terms of collaboration between countries, network collaboration was found between countries in Asia (Malaysia and Indonesia), Central Asia (Pakistan and Bangladesh), the Middle East (the United Arab Emirates and Bahrain), Europe (the UK) and North America (the USA). Originality/value This paper examines the evolution of takaful literature using bibliometric analysis. The findings and potential applications of this research could be very beneficial to scholars and researchers in creating more dynamic improvements in the scientific development of takaful.

Multiphysical Field Coupling Model for Simulating Thermal Stress and Deformation in Ferronickel Submerged Arc Furnace

To address the issue of thermal expansion and stress concentration in furnace body, a 3D multiphysical field coupling model of electromagnetics, fluid flow, and temperature is developed to predict the interaction mechanisms between temperature, thermal stress, and deformation during submerged arc furnace operation. This model integrates electromagnetism, electrothermal conversion, mass and heat transfer, and multiphase flow within a unified computational framework using user‐defined functions. Additionally, it conducts thermal mechanical coupling analyses to describe the thermal deformation and stress concentration behavior in the furnace body. The results indicate that the multiphysical field exhibits strong coupling and nonuniformity. Due to the high thermal resistance of the furnace body material, the temperature between the inner wall of the furnace lining and furnace shell decreases from 1212 to 467 K. When the electrode insertion depth increases from 1.8 to 2.2 m, the maximum temperature of furnace shell increases from 456 to 498 K, and the maximum deformation of furnace shell gradually increases from 28.0 to 30.1 mm. The maximum deformation position occurs at the height of z = 2.45 m. As the electrode insertion depth increases, the stress concentration phenomena in the rib plates, the bottom of furnace shell, and the central area of furnace bottom are enhanced.

Loss Research and Thermal Analysis of BLDC Hollow-Cup Motor Under Reactor Suppression

In order to avoid overheating of a BLDC permanent magnet (PM) motor at high speeds, this paper focuses on the loss reduction of a 90 W 47,000 r/min BLDC hollow-cup motor. It is proposed to provide an optimizing method for the series reactors and the parameterization of reactors in the motor system. The finite element method (FEM) is used to calculate and analyze the time harmonic of air-gap magnetic flux density, stator core loss, and rotor eddy current loss in two cases: with a series reactor and without a reactor. By parameterizing the inductance value, the optimal resistance value is determined to minimize motor loss. In addition, an electromagnetic–thermal coupling analysis is conducted, and the results show that the temperature distribution of the stator core, winding, and rotor are improved under reactor suppression. Finally, an experimental platform is built to verify the temperature increase and the efficiency of the motor load operation. A clear reference for the research and optimization analysis of motor loss reduction is provided.

Design and analysis of a novel high TC-superconducting coupling for high torque transmission and speed regulation: A Comparative study with slotted eddy current coupling

Design and analysis of a novel high TC-superconducting coupling for high torque transmission and speed regulation: A Comparative study with slotted eddy current coupling

Assessment of sleep quality using cardiopulmonary coupling and its predictive value for delirium in ICU patients.

To assess sleep quality in intensive care unit (ICU) patients using cardiopulmonary coupling (CPC) analysis and explore its predictive value for delirium. ICU patients (n=135) were divided into the delirium group (n=44) and control group (n=91) based on the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). CPC analysis was used to evaluate the sleep quality of all participants. Intergroup comparisons showed that total sleep time, stable sleep time, and sleep efficiency were significantly lower in the delirium group than in the control group, whereas unstable sleep time, rapid eye movement sleep time, wake-up time, stable sleep latency, and apnea-hypopnea index (AHI) were significantly higher in the delirium group than in the control group. Logistic regression analysis showed that advanced age and AHI were risk factors for delirium, whereas stable sleep time was a protective factor for delirium. Receiver operating characteristic (ROC) analysis showed that stable sleep time and stable sleep latency had a certain predictive value for delirium; the area under the ROC curve (AUC) for stable sleep time was higher (0.888 vs. 0.704). The cut-off value for stable sleep time was 0.65h, with a sensitivity of 84.1% and specificity of 81.3%. ICU patients with delirium have poorer sleep quality than patients without delirium. Stable sleep time derived from the CPC has a high predictive value for delirium and may serve as an objective indicator for its diagnosis.

Coupled dynamic analysis of moored floating structures by a hybrid Laplace-time domain method

The coupled dynamic analysis of moored floating structures has often been conducted in the time domain by iteratively solving the Cummins equation, treating the mooring effects as an additional nonlinear load. However, the time domain (TD) method requires performing a convolution integral at each time step, which is costly in computational time. This paper innovatively develops an efficient hybrid Laplace-time domain method (HLTD) on implementing the coupled dynamic analysis of moored floating structures. The proposed method divides the external load into a number of segments and models the mooring system by the catenary theory. Under each segment, while the iterative operations used in the TD method is borrowed to handle the coupled behavior, the HLTD method computes the motions of the floating structure under each iteration by the pole-residue operations in the Laplace domain (LD). As the complicated convolutional integral computation required in the TD method is replaced by simple algebraic pole-residue calculations in the complex plane, the HLTD method is more efficient. Additionally, the HLTD method derives analytical response solutions for the moored floating system. Its efficiency and accuracy are demonstrated by comparing with the TD method through a moored float-over barge to irregular waves.

Neutronic and thermal-hydraulic coupling analysis of the dynamic unfolding process of the LOTUS reactor

Neutronic and thermal-hydraulic coupling analysis of the dynamic unfolding process of the LOTUS reactor

Vibration transmission in lubricated piston-liner systems: Experimental and multi-physics coupled analysis

Vibration transmission in lubricated piston-liner systems: Experimental and multi-physics coupled analysis

Coupled analysis in magneto-electro-elastic material for moving semipermeable crack based on EMPS model using singular integral equation

Coupled analysis in magneto-electro-elastic material for moving semipermeable crack based on EMPS model using singular integral equation

Research on Evolutionary Path of Land Development System Towards Carbon Neutrality

Based on complex system theory and multi-dimensional coupling analysis paradigm, this study constructs a dynamic model covering land use, real estate development, and carbon emissions, and deeply explores the internal mechanism and evolution law of land development system in the process of moving toward a low-carbon path. Firstly, through nonlinear dynamics and bifurcation analysis, this study identifies three typical transformation paths that the system may experience: gradual, transitional, and hybrid, emphasizing the nonlinear, phased, and highly context-dependent characteristics of the transformation process. On this basis, early warning indicators and robustness analysis methods are introduced, which provide operational tools for identifying critical turning points in the system and improving the effectiveness and resilience of regulatory strategies. Furthermore, this paper proposes a multi-level regulation mechanism design framework, which combines the immediate feedback with the historical cumulative effect to achieve the refined guidance of land development patterns and carbon emission paths. The results provide a scientific basis and practical enlightenment for land use optimization, green infrastructure construction, and industrial structure adjustment under the background of realizing the “3060” dual carbon goal and the reform of territorial spatial planning in China. In the future, it is necessary to strengthen the empirical calibration of parameters, data-driven optimization, and collaborative research of multiple policy tools to further improve the applicability and decision-making reference value of the model.

E-commerce and the metaverse: present and future trends of consumers’ adoption

ABSTRACT The aim of this study is to evaluate the knowledge structure of e-commerce in the Metaverse, which comprises virtual reality, augmented reality, extended reality and mixed reality. The consumer shopping experience has changed with the advent of this metaverse technology in the e-commerce platform. Utilizing a science mapping approach through bibliometric analysis, two analyses of bibliographic coupling and co-word analysis were applied to uncover the current and future trends of e-commerce and the Metaverse. 211 journal publications were retrieved from the Web of Science (WoS), and VOSviewer was utilized to present the network structure of the research streams. Current and emerging themes suggest that most clusters are related to consumers’ interactivity and experience using metaverse technologies. The future trends are converged on the following consumer research streams: customer experience, acceptance interactivity and trust in Metaverse. Metaverse will inevitably be the future of e-commerce, and everyone must embrace and adapt to its evolution. Business owners and policymakers will benefit from the findings of this review to plan and design the most significant user-friendly metaverse service despite its sophisticated and complex technology. This study presents the gap in the literature of Metaverse from e-commerce by revealing the knowledge structure through science mapping of bibliometric technique.

Coupled modelling and analysis of lubrication-wear evolution of textured piston/cylinder pair in high-pressure common rail pumps

Abstract Surface texturing is an important approach to enhance fluid lubrication performance and reduce friction and wear. Research on the surface texturing of the piston/cylinder pair considering various characteristics such as multi-physical fields and the evolution of friction and wear is still insufficient. The novelty of this work aims to establish a coupled numerical simulation model considering the coupling effect of multiple physical fields, wear of the cylinder bore and surface texture, and determine the effective surface texture parameters to improve the friction performance of the mechanical components of high-pressure common rail pump. The influence of surface texture on friction and wear characteristics and the evolution of lubrication-wear under different geometric cases were in-depth investigated, and the action mechanism of surface texture on lubrication and wear was revealed. Through numerical analysis, optimal parameters were identified that significantly reduce the friction coefficient and wear amount, offering practical insights for mitigating friction and wear in mechanical systems.

Ovarian Endometrioma Disrupts Oocyte-Cumulus Communication and Mitochondrial Function, With Melatonin Mitigating the Effects.

Ovarian endometrioma (OEM), a particularly severe form of endometriosis, is an oestrogen-dependent condition often associated with pain and infertility. The mechanisms by which OEM impairs fertility, particularly through its direct impact on oocyte-cumulus cell (CC) communication and related pathways, remain poorly understood. This study investigates the impact of OEM on oocyte-CC communication and explores melatonin's therapeutic potential. We used a mouse model of OEM and employed ovarian transcriptome and gene set enrichment analyses to identify disrupted gene pathways, alongside phalloidin staining for cytoskeletal analysis, gap junction coupling analysis for intercellular communication, and mitochondrial function assessments for cellular metabolism. Our results showed that OEM significantly impairs steroidogenesis and cumulus cell function, leading to increased apoptosis, disrupted transzonal projections (TZPs), and impaired antioxidant transfer to oocytes. This culminates in oxidative stress, mitochondrial dysfunction, and compromised ATP production. OEM oocytes also exhibited severe abnormalities, including DNA damage, maturation defects, spindle assembly disruptions, and increased aneuploidy. This study identifies disrupted TZPs as a key pathological feature in OEM and highlights melatonin's potential to restore intercellular communication, mitigate oxidative damage, and improve reproductive outcomes.

Ecological Management Zoning Identification by Coupling Blue-Green and Gray Infrastructure Networks: A Case Study of Guizhou Province, China

Ecological management zoning is crucial for maintaining regional ecological security and realizing differentiated urban ecological governance. However, the existing zoning methods are overly focused on ecological functional attributes and fail to adequately consider the impacts of human activities, resulting in an insufficiently rational allocation of resources. Taking Guizhou Province as an example, using multi-source data and spatial analysis tools, this study proposed an ecological management zoning framework based on the coupling analysis of the blue-green infrastructure (BGI) network and gray infrastructure (GI) network. The results indicated that (1) the BGI network in the study area included 179 sources, with a total area of 54,228.80 km2, and 232 corridors. (2) There were 53 sources in the GI network, totaling 709.19 km2, and the corridors of the first, second, and third levels were 11,469.31 km, 6703.54 km, and 5341.30 km, respectively. (3) There were 606 barrier points identified, mainly distributed in the central part of the study area, and the total area of the disturbance zone was 1132.50 km2, which had the largest distribution in Qiandongnan, followed by Qiannan. (4) At the county scale, five ecological management zones were identified in the study area based on four indicators, namely, the source area ratio of BGI network, corridor density of BGI network disturbance zone area ratio, and density of barrier point. Then, we proposed targeted optimizations and restorations for each zone. This study organically linked ecological functional attributes and anthropogenic impacts to identify ecological management zones, which will provide new perspectives on synergies between ecological protection and economic development.

Three-Dimensional Aeroelastic Investigation of a Novel Convex Bladed H-Darrieus Wind Turbine Based on a Two-Way Coupled Computational Fluid Dynamics and Finite Element Analysis Approach

Three-Dimensional Aeroelastic Investigation of a Novel Convex Bladed H-Darrieus Wind Turbine Based on a Two-Way Coupled Computational Fluid Dynamics and Finite Element Analysis Approach