As smart contracts,represented by Solidity,become deeply integrated into the manufacturing industry,blockchain-based Digital Twins(DT)has gained momentum in recent years.Most of the blockchain infrastructures in wides...As smart contracts,represented by Solidity,become deeply integrated into the manufacturing industry,blockchain-based Digital Twins(DT)has gained momentum in recent years.Most of the blockchain infrastructures in widespread use today are based on the Proof-of-Work(PoW)mechanism,and the process of creating blocks is known as“mining”.Mining becomes increasingly difficult as the blockchain grows in size and the number of on-chain business systems increases.To lower the threshold of participation in the mining process,“mining pools”have been created.Miners can cooperate and share the mining rewards according to the hashrate they contributed to the pool.Stratum is the most widely used communication protocol between miners and mining pools.Its security is essential for the participants.In this paper,we propose two novel Man-In-The-Middle(MITM)attack schemes against Stratum,which allow attackers to steal miners'hashrate to any mining pool using hijacked TCP connections.Compared with existing attacks,our work is more secretive,more suitable for the real-world environment,and more harmful.The Proof-of-Concept(PoC)shows that our schemes work perfectly on most mining softwares and pools.Furthermore,we present a lightweight AI-driven approach based on protocol-level feature analysis to detect Stratum MITM for blockchain-based DTs.Its detection model consists of three layers:feature extraction layer,vectorization layer,and detection layer.Experiments prove that our detection approach can effectively detect Stratum MITM traffic with 98%accuracy.Our work alerts the communities and provides possible mitigation against these more hidden and profitable attack schemes.展开更多
The ascent of the metaverse signifies a profound transformation in our digital landscape, ushering in a complex network of interlinked virtual domains and digital spaces. In this burgeoning metaverse, a paradigm shift...The ascent of the metaverse signifies a profound transformation in our digital landscape, ushering in a complex network of interlinked virtual domains and digital spaces. In this burgeoning metaverse, a paradigm shift is seen in how people engage, collaborate, and become immersed in digital environments. An especially intriguing concept taking root within this metaverse landscape is that of digital twins. Initially rooted in industrial and Internet of Things(IoT) contexts, digital twins are now making their mark in the metaverse, presenting opportunities to elevate user experiences, introduce novel dimensions of interaction, and seamlessly bridge the divide between the virtual and physical realms. Digital twins, conceived initially to replicate physical entities in real-time, have transcended their industrial origins in this new metaverse context. They no longer solely replicate physical objects but extend their domain to encompass digital entities, avatars, virtual environments, and users. Despite the vital contributions of digital twins in the metaverse, there has been no research that has explored the applications and scope of digital twins in the metaverse comprehensively. However, there are a few papers focusing on some particular applications. Addressing this research gap, we present an in-depth review of the pivotal role of application digital twins in the metaverse. We present 15 digital twin applications in the metaverse, ranging from simulation and training to emergency preparedness. This study outlines the critical limitations of integrating digital twins and metaverse and several future research directions.展开更多
Digital twins(DTs)are rapidly emerging as transformative tools in materials science and engineering,enabling real-time data integration,predictive modeling,and virtual testing.This study presents a systematic bibliome...Digital twins(DTs)are rapidly emerging as transformative tools in materials science and engineering,enabling real-time data integration,predictive modeling,and virtual testing.This study presents a systematic bibliometric review of 1106 peer-reviewed articles published in the last decade in Scopus and Web of Science.Using a five-stage methodology,the review examines publication trends,thematic areas,citation metrics,and keyword patterns.The results reveal exponential growth in scientific output,with Materials Theory,Computation,and Data Science as the most represented area.A thematic analysis of the most cited documents identifies four major research streams:foundational frameworks,DTs in additive manufacturing,sector-specific applications,and intelligent production systems.Keyword co-occurrence and strategic mapping show a strong foundation in modeling,simulation,and optimization,with growing links to machine learning and sustainability.The review highlights current challenges and proposes future research directions for advancing DTs in materials science.展开更多
Integrating mobile edge computing (MEC) and digital twin (DT) technologies to enhance network performance through predictive, adaptive control for energy-efficient and low-latency communication is a significant challe...Integrating mobile edge computing (MEC) and digital twin (DT) technologies to enhance network performance through predictive, adaptive control for energy-efficient and low-latency communication is a significant challenge. This paper presents the EcoEdgeTwin model, an innovative framework that harnesses the harmony between MEC and DT technologies to ensure an efficient network operation. We optimise the utility function to balance enhancing users' quality of experience (QoE) and minimising latency and energy consumption at edge servers. This approach ensures efficient and adaptable network operations, utilising DT to synchronise and integrate real-time data seamlessly. Our framework implements robust mechanisms for task offloading, service caching and cost-effective service migration. Additionally, it manages energy consumption related to task processing, communication and the influence of DT predictions, all essential for optimising latency and minimising energy usage. Through the utility model, we also prioritise QoE, fostering a user-centric approach to network management that balances network efficiency with user satisfaction. A cornerstone of our approach is integrating the advantage actor-critic algorithm, marking a pioneering use of deep reinforcement learning for dynamic network management. This strategy addresses challenges in service mobility and network variability, ensuring optimal network performance matrices. Our extensive simulations demonstrate that compared to benchmark models, the EcoEdgeTwin framework significantly reduces energy usage and latency while enhancing QoE.展开更多
Face-centered cubic(FCC)-structured multicomponent alloys typically exhibit good ductility but low strength.To simultaneously improve strength and ductility,a multicomponent alloy,Ni_(43.9)Co_(22.4)Fe_(8.8)Al_(10.7)Ti...Face-centered cubic(FCC)-structured multicomponent alloys typically exhibit good ductility but low strength.To simultaneously improve strength and ductility,a multicomponent alloy,Ni_(43.9)Co_(22.4)Fe_(8.8)Al_(10.7)Ti_(11.7)B_(2.5)(at%)with a unique microstructure was developed in this work.The microstructure,which includes 17.8%nanosized L12 precipitates and 26.6%micron-sized annealing twins distributed within~8μm fine FCC grains,was achieved through cryogenic rolling and subsequent annealing.The alloy exhibits a yield strength(YS)of 1063 MPa,ultimate tensile strength(UTS)of 1696 MPa,and excellent elongation of~26%.The L1_(2) precipitates and high-density grain boundaries act as a barrier to the dislocation movement,resulting in a substantial strengthening effect.In addition,the dislocations can cut through the L1_(2) precipitates that are coherent with the FCC matrix,whereas the twin boundaries can effectively absorb and store dislocations,leading to a high work-hardening rate.Furthermore,the stacking faults,Lomer-Cottrell locks,and 9-layer rhombohedral stacking sequence(9R)structures formed during tensile deformation significantly enhance strain hardening by blocking dislocation movement and accumulating dislocations,resulting in excellent comprehensive tensile properties.Theoretical calculations reveal that the grain boundaries,L1_(2)precipitates,and twin boundaries contribute the strengths of 263.8,412.6,and 68.7 MPa,respectively,accounting for 71.9%of the YS.This study introduces a promising strategy for developing multicomponent alloys with significant strength-ductility synergies.展开更多
Context: The presence of conjoined twins is a rare occurrence during pregnancy. Today, early diagnosis is possible thanks to advances in imaging, particularly three-dimensional ultrasound, and the intervention of a tr...Context: The presence of conjoined twins is a rare occurrence during pregnancy. Today, early diagnosis is possible thanks to advances in imaging, particularly three-dimensional ultrasound, and the intervention of a trained operator. This antenatal diagnosis can be used to decide whether or not to continue the pregnancy. Cases presentation: Based on the authors’ experience, five (05) cases of conjoined twins were collected over a period of six years (01 January 2018-01 January 2023) in the maternity wards of the Angre’s Teaching Hospital (study location), whose diagnosis was sometimes unexpected in the delivery room. Among the five cases, we described three (03) thoraco-omphalopages and two (02) parapages, with a female predominance of 4/5. None were candidates for separation because they were stillborn or died on the first day of life. Conclusion: This series of cases highlights the different characteristics of conjoined twins and the poor fetal prognosis due to diagnostic difficulties and therapeutic possibilities that are practically non-existent in the African environment.展开更多
It is difficult to generate coherent twin boundaries in bulk Al alloys due to their high intrinsic stacking fault energy. Here, we report a strategy to induce high-density growth twins in aluminum alloys through the h...It is difficult to generate coherent twin boundaries in bulk Al alloys due to their high intrinsic stacking fault energy. Here, we report a strategy to induce high-density growth twins in aluminum alloys through the heterogeneous nucleation of twinned Al grains on twin-structured TiC nucleants and the preferred growth of twinned dendrites by laser surface remelting of bulk metals. The solidification structure at the surface shows a mixture of lamellar twinned dendrites with ultra-fine twin boundary spacing (∼2 µm), isolated twinned dendrites, and regular dendrites. EBSD analysis and finite element method (FEM) simulations have been used to understand the competitive growth between twinned and regular dendrites, and the solidification conditions for the preferred growth of twinned dendrites during laser remelting and subsequent rapid solidification are established. It is shown that the reduction in the ratio of temperature gradient G to solidification rate V promotes the formation of lamellar twinned dendrites. The primary trunk spacing of lamellar twinned dendrites is refined by the high thermal gradient and solidification rate. The present work paves a new way to generate high-density growth twins in additive-manufactured Al alloys.展开更多
Twinning is a deformation mechanism that creates three-dimensional(3D)twin domains through the migration of twin facets.This occurs via the nucleation and glide of twinning disconnections(TDs),which can pile up to cre...Twinning is a deformation mechanism that creates three-dimensional(3D)twin domains through the migration of twin facets.This occurs via the nucleation and glide of twinning disconnections(TDs),which can pile up to create twin facets.A comprehensive under-standing of twin facets associated with 3D twins,including their atomic structures and energies,is crucial for understanding deformation twinning.In this study,we propose a molecular statics/dynamics(MS/MD)approach to determine characteristic twin facets enclosing 3D non-equilibrium/equilibrium{1011}twin domains,which has been much less studied than the counterpart{1012}twin domains.The stability of different TD pile-up arrangement with varying line senses informs the morphology of 3D non-equilibrium twins,which are bounded by{1010}_(T)||{1013}_(M),{1011}_(T)||{0002}_(M)and{1013}_(T)||{1013}_(M)coherent facets associated with pile-up of edge TDs,and discrete non-edge TDs aligned along CTBs with their line senses parallel to<4513>,<1101>,<5416><2113>or<1012>axes.Formation of semi-coherent facets of equilibrium twins is accompanied by rearrangement of TDs around misfit dislocations.3D equilibrium{1011}twins may comprise{1011}_(T)||{0002}_(M),{1457}_(T)||{3419}_(M),{1657}_(T)||{5617}_(M),{1433}_(T)||{3413}_(M),{0110}_(T)||{0111}_(M)and{0221}_(T)||{0221}_(M)semi-coherent facets in<1210>,<4513>,<1101>,<5416>,<2113>and<1012>axes,respectively.展开更多
A high-purity Ti sheet with dense preexisting twins(introduced by 10%cold rolling)was subjected to isochronal annealing at 500–800°C for 1 h and isothermal annealing at 600°C for 0.17–100 h,respectively.By...A high-purity Ti sheet with dense preexisting twins(introduced by 10%cold rolling)was subjected to isochronal annealing at 500–800°C for 1 h and isothermal annealing at 600°C for 0.17–100 h,respectively.By mainly utilizing electron backscatter diffraction(EBSD)and electron channel contrast(ECC)imaging techniques,the microstructure and texture evolution during the isochronal and isothermal annealing were investigated systematically.Results show that recrystallization nuclei appear in the specimen annealed at 600°C for 1 h.In contrast,recrystallization cannot be initiated for those annealed at lower temperatures or for a shorter time.With the increase in temperature or time,the fraction of the recrystallized structure increases with gradual grain coarsening.Nearly complete recrystallization is reached after 800°C-1 h or 600°C-100 h annealing.Due to the distribution heterogeneity of microstructure and stored energy induced by the dense preexisting twins,recrystallization nucleation preferentially occurs in some specific regions(twin-twin or twin-grain boundary junctions).Then,they selectively consume twin lamellar structures,leading to non-uniform grain growth.It is demonstrated that the recrystallization nucleation is dominated by the strain-induced boundary migration mechanism,allowing scattered texture components corresponding to the twin lamellar structures to be gradually encroached by those untwinned structures with the initial bimodal basal texture(BBT).Eventually,a strong BBT is always obtained after sufficient recrystallization.展开更多
Cold-rolling was conducted on AZ31 magnesium alloy with fine and coarse grains to produce plates with high density of shear bands and{101^(-)1}twins,respectively.Then,these two kinds of plates are subjected to isother...Cold-rolling was conducted on AZ31 magnesium alloy with fine and coarse grains to produce plates with high density of shear bands and{101^(-)1}twins,respectively.Then,these two kinds of plates are subjected to isothermal annealing to reveal the effect of shear bands and{101^(-)1}twins on recrystallization behavior.During annealing,static recrystallization occurs firstly in shear band zones and{101^(-)1}twin zones,which has different effect on texture and mechanical properties.With the increase of annealing temperature,strong basal texture remains in annealed SG-17%while the basal texture is weakened gradually in annealed LG-15%.Recrystallized grains from twin zones have a random orientation which is responsible for the weakened basal texture in annealed LG-15%.In addition,microhardness decreases gradually with the prolonged annealing time due to static recrystallization.LG-15%has a lower recrystallization activation energy because{101^(-)1}twins are in favor of the nucleation and growth of recrystallized grains.After 500℃annealing,the yield strength decreases significantly with a significant improvement in failure strain.The annealed LG-15%has a much higher compressive strain than the annealed SG-17%due to texture weakening effect.展开更多
The paper considers the poor state of the construction industry in UK and ways in which it might improve for all stakeholders.The transition from present state to a desirable future is mapped using the“three horizons...The paper considers the poor state of the construction industry in UK and ways in which it might improve for all stakeholders.The transition from present state to a desirable future is mapped using the“three horizons”and“four capitals”concepts.Servitisation is suggested as a key innovation for engineering systems in buildings,the dominant lifecycle cost area.Digital twinning facilitates this method of provision and blockchain technology can support its commercialisation,enabling payments for service delivered and keeping safe records.展开更多
The Internet of Medical Things(IoMT)is transforming healthcare by enabling real-time data collection,analysis,and personalized treatment through interconnected devices such as sensors and wearables.The integration of ...The Internet of Medical Things(IoMT)is transforming healthcare by enabling real-time data collection,analysis,and personalized treatment through interconnected devices such as sensors and wearables.The integration of Digital Twins(DTs),the virtual replicas of physical components and processes,has also been found to be a game changer for the ever-evolving IoMT.However,these advancements in the healthcare domain come with significant cybersecurity challenges,exposing it to malicious attacks and several security threats.Intrusion Detection Systems(IDSs)serve as a critical defense mechanism,yet traditional IDS approaches often struggle with the complexity and scale of IoMT networks.With this context,this paper follows a systematic approach to analyze the existing literature and highlight the current trends and challenges related to IDS in the IoMT domain.We leveraged techniques like bibliographic and keyword analysis to collect 832 research works published from 2007 to 2025,aligned with the theme“Digital Twins and IDS in IoMT.”It was found that by simulating device behaviours and network interactions in IoMT,DTs not only provide a proactive platform for early threat detection,but also offer a scalable and adaptive approach to mitigating evolving security threats in IoMT.Overall,this review provides a closer look into the role of IDS and DT in securing IoMT systems and sheds light on the possible research directions for developers and the research community.展开更多
Cyber-Physical Systems(CPS)represent an integration of computational and physical elements,revolutionizing industries by enabling real-time monitoring,control,and optimization.A complementary technology,Digital Twin(D...Cyber-Physical Systems(CPS)represent an integration of computational and physical elements,revolutionizing industries by enabling real-time monitoring,control,and optimization.A complementary technology,Digital Twin(DT),acts as a virtual replica of physical assets or processes,facilitating better decision making through simulations and predictive analytics.CPS and DT underpin the evolution of Industry 4.0 by bridging the physical and digital domains.This survey explores their synergy,highlighting how DT enriches CPS with dynamic modeling,realtime data integration,and advanced simulation capabilities.The layered architecture of DTs within CPS is examined,showcasing the enabling technologies and tools vital for seamless integration.The study addresses key challenges in CPS modeling,such as concurrency and communication,and underscores the importance of DT in overcoming these obstacles.Applications in various sectors are analyzed,including smart manufacturing,healthcare,and urban planning,emphasizing the transformative potential of CPS-DT integration.In addition,the review identifies gaps in existing methodologies and proposes future research directions to develop comprehensive,scalable,and secure CPSDT systems.By synthesizing insights fromthe current literature and presenting a taxonomy of CPS and DT,this survey serves as a foundational reference for academics and practitioners.The findings stress the need for unified frameworks that align CPS and DT with emerging technologies,fostering innovation and efficiency in the digital transformation era.展开更多
The management of large-scale architectural engineering projects(e.g.,airports,hospitals)is plagued by information silos,cost overruns,and scheduling delays.While building information modeling(BIM)has improved 3D desi...The management of large-scale architectural engineering projects(e.g.,airports,hospitals)is plagued by information silos,cost overruns,and scheduling delays.While building information modeling(BIM)has improved 3D design coordination,its static nature limits its utility in real-time construction management and operational phases.This paper proposes a novel synergistic framework that integrates the static,deep data of BIM with the dynamic,real-time capabilities of digital twin(DT)technology.The framework establishes a closed-loop data flow from design(BIM)to construction(IoT,drones,BIM 360)to operation(DT platform).We detail the technological stack required,including IoT sensors,cloud computing,and AI-driven analytics.The application of this framework is illustrated through a simulated case study of a mega-terminal airport construction project,demonstrating potential reductions in rework by 15%,improvement in labor productivity by 10%,and enhanced predictive maintenance capabilities.This research contributes to the field of construction engineering by providing a practical model for achieving full lifecycle digitalization and intelligent project management.展开更多
In this paper,we explore the ever-changing field ofDigital Twins(DT)in the Industrial Internet of Things(IIoT)context,emphasizing their critical role in advancing Industry 4.0 toward the frontiers of Industry 5.0.The ...In this paper,we explore the ever-changing field ofDigital Twins(DT)in the Industrial Internet of Things(IIoT)context,emphasizing their critical role in advancing Industry 4.0 toward the frontiers of Industry 5.0.The article explores the applications of DT in several industrial sectors and their smooth integration into the IIoT,focusing on the fundamentals of digital twins and emphasizing the importance of virtual-real integration.It discusses the emergence of DT,contextualizing its evolution within the framework of IIoT.The study categorizes the different types of DT,including prototypes and instances,and provides an in-depth analysis of the enabling technologies such as IoT,Artificial Intelligence(AI),Extended Reality(XR),cloud computing,and the Application Programming Interface(API).The paper demonstrates theDT advantages through the practical integration of real-world case studies,which highlights the technology’s exceptional capacity to improve traceability and fault detection within the context of the IIoT.This paper offers a focused,application-driven perspective on DTs in IIoT,specifically highlighting their role in key production phases such as designing,intelligent manufacturing,maintenance,resource management,automation,security,and safety.By emphasizing their potential to support human-centric,sustainable advancements in Industry 5.0,this study distinguishes itself from existing literature.It provides valuable insights that connect theoretical advancements with practical implementation,making it a crucial resource for researchers,practitioners,and industry professionals.展开更多
Predictive maintenance is essential for the implementation of an innovative and efficient structural health monitoring strategy.Models capable of accurately interpreting new data automatically collected by suitably pl...Predictive maintenance is essential for the implementation of an innovative and efficient structural health monitoring strategy.Models capable of accurately interpreting new data automatically collected by suitably placed sensors to assess the state of the infrastructure represent a fundamental step,particularly for the railway sector,whose safe and continuous operation plays a strategic role in the well-being and development of nations.In this scenario,the benefits of a digital twin of a bonded insu-lated rail joint(IRJ)with the predictive capabilities of advanced classification algorithms based on artificial intelligence have been explored.The digital model provides an accurate mechanical response of the infrastructure as a pair of wheels passes over the joint.As bolt preload conditions vary,four structural health classes were identified for the joint.Two parameters,i.e.gap value and vertical displacement,which are strongly correlated with bolt preload,are used in different combinations to train and test five predictive classifiers.Their classification effectiveness was assessed using several performance indica-tors.Finally,we compared the IRJ condition predictions of two trained classifiers with the available data,confirming their high accuracy.The approach presented provides an interesting solution for future predictive tools in SHM especially in the case of complex systems such as railways where the vehicle-infrastructure interaction is complex and always time varying.展开更多
To understand the tensile deformation of electro-deposited Cu with nano-scale twins, a numerical study was carried out based on a conventional theory of mechanism-based strain gradient plasticity （CMSG）. The concept...To understand the tensile deformation of electro-deposited Cu with nano-scale twins, a numerical study was carried out based on a conventional theory of mechanism-based strain gradient plasticity （CMSG）. The concept of twin lamella strengthening zone was used in terms of the cohesive interface model to simulate grain-boundary sliding and separation. The model included a number of material parameters, such as grain size, elastic modulus, plastic strain hardening exponent, initial yield stress, as well as twin lamellar distribution, which may contribute to size effects of twin layers in Cu polycrystalline. The results provide information to understand the mechanical behaviors of Cu with nano-scale growth twins.展开更多
In order to investigate the dependence of microstructure and mechanical properties on the rolling process parameters, AZ31 magnesium alloy sheets with different grain sizes, basal texture intensities and twinning type...In order to investigate the dependence of microstructure and mechanical properties on the rolling process parameters, AZ31 magnesium alloy sheets with different grain sizes, basal texture intensities and twinning types were obtained using hot rolling at various temperatures and reductions. The volume fractions of the extension, contraction and secondary twins in the as-rolled sheets depend on the grain size. The highest volume fractions of three types of twins are obtained at 523 K under the reduction of 10% when the average grain size value is the maximum. The critical reductions for complete dynamic recrystallization are 30% at 523 K and 40% at 473 K. The increase of yield strength is ascribed to both grain-refinement strengthening and basal texture strengthening at the first stage. When the grain size does not decrease with increasing the reduction, the yield strength is mainly influenced by the texture weakening.展开更多
Due to lattice reorientation,grain segmentation,induced recrystallization,twins play a very important role in regulating texture,refining grains,improving mechanical properties and corrosion resistance,and has receive...Due to lattice reorientation,grain segmentation,induced recrystallization,twins play a very important role in regulating texture,refining grains,improving mechanical properties and corrosion resistance,and has received more extensive attention.Numerous studies have shown that{10-12}<10-11>tensile twins(TTWs)are easily activated in large quantities due to the lower critical resolve shear stresses(CRSS).Introduction of TTWs under uniaxial compression improved the strength,ductility,and formability of magnesium(Mg)alloys.Moreover,TTWs produced by multi-directional impact forging(MDIF)can optimize the microstructure by dividing grains and promoting recrystallization,resulting in significant improvement of mechanical properties.Although{10-11}<10-12>compressive twins(CTWs)and{10-11}-{10-12}double twins(DTWs)can promote dynamic recrystallization(DRX),they are also favorable nucleation sites for cracks.In addition,the type and volume fraction of twins can affect the corrosion resistance,and they also play different roles in the corrosion process of different Mg alloys.Twins have shown great potential for improving structure and properties,but a comprehensive and critical discussion of twins in Mg alloys is still lacking.Therefore,based on previous studies,this article reviews the common types and variants of twins in Mg alloys,influencing factors,and their effects on the microstructure,mechanical properties and corrosion resistance.In addition,some interesting ideas are being proposed for further research.展开更多
文摘As smart contracts,represented by Solidity,become deeply integrated into the manufacturing industry,blockchain-based Digital Twins(DT)has gained momentum in recent years.Most of the blockchain infrastructures in widespread use today are based on the Proof-of-Work(PoW)mechanism,and the process of creating blocks is known as“mining”.Mining becomes increasingly difficult as the blockchain grows in size and the number of on-chain business systems increases.To lower the threshold of participation in the mining process,“mining pools”have been created.Miners can cooperate and share the mining rewards according to the hashrate they contributed to the pool.Stratum is the most widely used communication protocol between miners and mining pools.Its security is essential for the participants.In this paper,we propose two novel Man-In-The-Middle(MITM)attack schemes against Stratum,which allow attackers to steal miners'hashrate to any mining pool using hijacked TCP connections.Compared with existing attacks,our work is more secretive,more suitable for the real-world environment,and more harmful.The Proof-of-Concept(PoC)shows that our schemes work perfectly on most mining softwares and pools.Furthermore,we present a lightweight AI-driven approach based on protocol-level feature analysis to detect Stratum MITM for blockchain-based DTs.Its detection model consists of three layers:feature extraction layer,vectorization layer,and detection layer.Experiments prove that our detection approach can effectively detect Stratum MITM traffic with 98%accuracy.Our work alerts the communities and provides possible mitigation against these more hidden and profitable attack schemes.
文摘The ascent of the metaverse signifies a profound transformation in our digital landscape, ushering in a complex network of interlinked virtual domains and digital spaces. In this burgeoning metaverse, a paradigm shift is seen in how people engage, collaborate, and become immersed in digital environments. An especially intriguing concept taking root within this metaverse landscape is that of digital twins. Initially rooted in industrial and Internet of Things(IoT) contexts, digital twins are now making their mark in the metaverse, presenting opportunities to elevate user experiences, introduce novel dimensions of interaction, and seamlessly bridge the divide between the virtual and physical realms. Digital twins, conceived initially to replicate physical entities in real-time, have transcended their industrial origins in this new metaverse context. They no longer solely replicate physical objects but extend their domain to encompass digital entities, avatars, virtual environments, and users. Despite the vital contributions of digital twins in the metaverse, there has been no research that has explored the applications and scope of digital twins in the metaverse comprehensively. However, there are a few papers focusing on some particular applications. Addressing this research gap, we present an in-depth review of the pivotal role of application digital twins in the metaverse. We present 15 digital twin applications in the metaverse, ranging from simulation and training to emergency preparedness. This study outlines the critical limitations of integrating digital twins and metaverse and several future research directions.
文摘Digital twins(DTs)are rapidly emerging as transformative tools in materials science and engineering,enabling real-time data integration,predictive modeling,and virtual testing.This study presents a systematic bibliometric review of 1106 peer-reviewed articles published in the last decade in Scopus and Web of Science.Using a five-stage methodology,the review examines publication trends,thematic areas,citation metrics,and keyword patterns.The results reveal exponential growth in scientific output,with Materials Theory,Computation,and Data Science as the most represented area.A thematic analysis of the most cited documents identifies four major research streams:foundational frameworks,DTs in additive manufacturing,sector-specific applications,and intelligent production systems.Keyword co-occurrence and strategic mapping show a strong foundation in modeling,simulation,and optimization,with growing links to machine learning and sustainability.The review highlights current challenges and proposes future research directions for advancing DTs in materials science.
文摘Integrating mobile edge computing (MEC) and digital twin (DT) technologies to enhance network performance through predictive, adaptive control for energy-efficient and low-latency communication is a significant challenge. This paper presents the EcoEdgeTwin model, an innovative framework that harnesses the harmony between MEC and DT technologies to ensure an efficient network operation. We optimise the utility function to balance enhancing users' quality of experience (QoE) and minimising latency and energy consumption at edge servers. This approach ensures efficient and adaptable network operations, utilising DT to synchronise and integrate real-time data seamlessly. Our framework implements robust mechanisms for task offloading, service caching and cost-effective service migration. Additionally, it manages energy consumption related to task processing, communication and the influence of DT predictions, all essential for optimising latency and minimising energy usage. Through the utility model, we also prioritise QoE, fostering a user-centric approach to network management that balances network efficiency with user satisfaction. A cornerstone of our approach is integrating the advantage actor-critic algorithm, marking a pioneering use of deep reinforcement learning for dynamic network management. This strategy addresses challenges in service mobility and network variability, ensuring optimal network performance matrices. Our extensive simulations demonstrate that compared to benchmark models, the EcoEdgeTwin framework significantly reduces energy usage and latency while enhancing QoE.
基金supported by the Major Science and Technology Project of Gansu Province(Nos.23ZDGA010 and 22ZD6GA008)the National Natural Science Foundation of China(No.51564035).
文摘Face-centered cubic(FCC)-structured multicomponent alloys typically exhibit good ductility but low strength.To simultaneously improve strength and ductility,a multicomponent alloy,Ni_(43.9)Co_(22.4)Fe_(8.8)Al_(10.7)Ti_(11.7)B_(2.5)(at%)with a unique microstructure was developed in this work.The microstructure,which includes 17.8%nanosized L12 precipitates and 26.6%micron-sized annealing twins distributed within~8μm fine FCC grains,was achieved through cryogenic rolling and subsequent annealing.The alloy exhibits a yield strength(YS)of 1063 MPa,ultimate tensile strength(UTS)of 1696 MPa,and excellent elongation of~26%.The L1_(2) precipitates and high-density grain boundaries act as a barrier to the dislocation movement,resulting in a substantial strengthening effect.In addition,the dislocations can cut through the L1_(2) precipitates that are coherent with the FCC matrix,whereas the twin boundaries can effectively absorb and store dislocations,leading to a high work-hardening rate.Furthermore,the stacking faults,Lomer-Cottrell locks,and 9-layer rhombohedral stacking sequence(9R)structures formed during tensile deformation significantly enhance strain hardening by blocking dislocation movement and accumulating dislocations,resulting in excellent comprehensive tensile properties.Theoretical calculations reveal that the grain boundaries,L1_(2)precipitates,and twin boundaries contribute the strengths of 263.8,412.6,and 68.7 MPa,respectively,accounting for 71.9%of the YS.This study introduces a promising strategy for developing multicomponent alloys with significant strength-ductility synergies.
文摘Context: The presence of conjoined twins is a rare occurrence during pregnancy. Today, early diagnosis is possible thanks to advances in imaging, particularly three-dimensional ultrasound, and the intervention of a trained operator. This antenatal diagnosis can be used to decide whether or not to continue the pregnancy. Cases presentation: Based on the authors’ experience, five (05) cases of conjoined twins were collected over a period of six years (01 January 2018-01 January 2023) in the maternity wards of the Angre’s Teaching Hospital (study location), whose diagnosis was sometimes unexpected in the delivery room. Among the five cases, we described three (03) thoraco-omphalopages and two (02) parapages, with a female predominance of 4/5. None were candidates for separation because they were stillborn or died on the first day of life. Conclusion: This series of cases highlights the different characteristics of conjoined twins and the poor fetal prognosis due to diagnostic difficulties and therapeutic possibilities that are practically non-existent in the African environment.
基金supported by the National Natural Science Foundation of China(grant no.52371029)the Science and Technology Development Program of Jilin Province,China(grant no.20210402083GH).
文摘It is difficult to generate coherent twin boundaries in bulk Al alloys due to their high intrinsic stacking fault energy. Here, we report a strategy to induce high-density growth twins in aluminum alloys through the heterogeneous nucleation of twinned Al grains on twin-structured TiC nucleants and the preferred growth of twinned dendrites by laser surface remelting of bulk metals. The solidification structure at the surface shows a mixture of lamellar twinned dendrites with ultra-fine twin boundary spacing (∼2 µm), isolated twinned dendrites, and regular dendrites. EBSD analysis and finite element method (FEM) simulations have been used to understand the competitive growth between twinned and regular dendrites, and the solidification conditions for the preferred growth of twinned dendrites during laser remelting and subsequent rapid solidification are established. It is shown that the reduction in the ratio of temperature gradient G to solidification rate V promotes the formation of lamellar twinned dendrites. The primary trunk spacing of lamellar twinned dendrites is refined by the high thermal gradient and solidification rate. The present work paves a new way to generate high-density growth twins in additive-manufactured Al alloys.
基金supports by the National Key R&D Program of China(No.2022YFB3708900).
文摘Twinning is a deformation mechanism that creates three-dimensional(3D)twin domains through the migration of twin facets.This occurs via the nucleation and glide of twinning disconnections(TDs),which can pile up to create twin facets.A comprehensive under-standing of twin facets associated with 3D twins,including their atomic structures and energies,is crucial for understanding deformation twinning.In this study,we propose a molecular statics/dynamics(MS/MD)approach to determine characteristic twin facets enclosing 3D non-equilibrium/equilibrium{1011}twin domains,which has been much less studied than the counterpart{1012}twin domains.The stability of different TD pile-up arrangement with varying line senses informs the morphology of 3D non-equilibrium twins,which are bounded by{1010}_(T)||{1013}_(M),{1011}_(T)||{0002}_(M)and{1013}_(T)||{1013}_(M)coherent facets associated with pile-up of edge TDs,and discrete non-edge TDs aligned along CTBs with their line senses parallel to<4513>,<1101>,<5416><2113>or<1012>axes.Formation of semi-coherent facets of equilibrium twins is accompanied by rearrangement of TDs around misfit dislocations.3D equilibrium{1011}twins may comprise{1011}_(T)||{0002}_(M),{1457}_(T)||{3419}_(M),{1657}_(T)||{5617}_(M),{1433}_(T)||{3413}_(M),{0110}_(T)||{0111}_(M)and{0221}_(T)||{0221}_(M)semi-coherent facets in<1210>,<4513>,<1101>,<5416>,<2113>and<1012>axes,respectively.
基金financially supported by the Cultivation Project of CQUT for Research and Innovation Group(No.2023TDZ006)the Graduate Student Innovation Program of CQUT(No.CYS23648)the Postdoctoral Science Foundation of China(No.2021M690174)。
文摘A high-purity Ti sheet with dense preexisting twins(introduced by 10%cold rolling)was subjected to isochronal annealing at 500–800°C for 1 h and isothermal annealing at 600°C for 0.17–100 h,respectively.By mainly utilizing electron backscatter diffraction(EBSD)and electron channel contrast(ECC)imaging techniques,the microstructure and texture evolution during the isochronal and isothermal annealing were investigated systematically.Results show that recrystallization nuclei appear in the specimen annealed at 600°C for 1 h.In contrast,recrystallization cannot be initiated for those annealed at lower temperatures or for a shorter time.With the increase in temperature or time,the fraction of the recrystallized structure increases with gradual grain coarsening.Nearly complete recrystallization is reached after 800°C-1 h or 600°C-100 h annealing.Due to the distribution heterogeneity of microstructure and stored energy induced by the dense preexisting twins,recrystallization nucleation preferentially occurs in some specific regions(twin-twin or twin-grain boundary junctions).Then,they selectively consume twin lamellar structures,leading to non-uniform grain growth.It is demonstrated that the recrystallization nucleation is dominated by the strain-induced boundary migration mechanism,allowing scattered texture components corresponding to the twin lamellar structures to be gradually encroached by those untwinned structures with the initial bimodal basal texture(BBT).Eventually,a strong BBT is always obtained after sufficient recrystallization.
基金Project(52405369) supported by National Natural Science Foundation of ChinaProject(BK20210891) supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(BX2022030) supported by the Special Project of Introducing Foreign Talents of Jiangsu Province,China。
文摘Cold-rolling was conducted on AZ31 magnesium alloy with fine and coarse grains to produce plates with high density of shear bands and{101^(-)1}twins,respectively.Then,these two kinds of plates are subjected to isothermal annealing to reveal the effect of shear bands and{101^(-)1}twins on recrystallization behavior.During annealing,static recrystallization occurs firstly in shear band zones and{101^(-)1}twin zones,which has different effect on texture and mechanical properties.With the increase of annealing temperature,strong basal texture remains in annealed SG-17%while the basal texture is weakened gradually in annealed LG-15%.Recrystallized grains from twin zones have a random orientation which is responsible for the weakened basal texture in annealed LG-15%.In addition,microhardness decreases gradually with the prolonged annealing time due to static recrystallization.LG-15%has a lower recrystallization activation energy because{101^(-)1}twins are in favor of the nucleation and growth of recrystallized grains.After 500℃annealing,the yield strength decreases significantly with a significant improvement in failure strain.The annealed LG-15%has a much higher compressive strain than the annealed SG-17%due to texture weakening effect.
文摘The paper considers the poor state of the construction industry in UK and ways in which it might improve for all stakeholders.The transition from present state to a desirable future is mapped using the“three horizons”and“four capitals”concepts.Servitisation is suggested as a key innovation for engineering systems in buildings,the dominant lifecycle cost area.Digital twinning facilitates this method of provision and blockchain technology can support its commercialisation,enabling payments for service delivered and keeping safe records.
基金This research is conducted as part of the project titled“Digital Twin-based Intrusion Detection System Using Federated Learning for IoMT”(2024-2027),supported by C3iHub,IIT Kanpur,India,under Sanction Order No.:IHUB-NTIHAC/2024/01/3.
文摘The Internet of Medical Things(IoMT)is transforming healthcare by enabling real-time data collection,analysis,and personalized treatment through interconnected devices such as sensors and wearables.The integration of Digital Twins(DTs),the virtual replicas of physical components and processes,has also been found to be a game changer for the ever-evolving IoMT.However,these advancements in the healthcare domain come with significant cybersecurity challenges,exposing it to malicious attacks and several security threats.Intrusion Detection Systems(IDSs)serve as a critical defense mechanism,yet traditional IDS approaches often struggle with the complexity and scale of IoMT networks.With this context,this paper follows a systematic approach to analyze the existing literature and highlight the current trends and challenges related to IDS in the IoMT domain.We leveraged techniques like bibliographic and keyword analysis to collect 832 research works published from 2007 to 2025,aligned with the theme“Digital Twins and IDS in IoMT.”It was found that by simulating device behaviours and network interactions in IoMT,DTs not only provide a proactive platform for early threat detection,but also offer a scalable and adaptive approach to mitigating evolving security threats in IoMT.Overall,this review provides a closer look into the role of IDS and DT in securing IoMT systems and sheds light on the possible research directions for developers and the research community.
文摘Cyber-Physical Systems(CPS)represent an integration of computational and physical elements,revolutionizing industries by enabling real-time monitoring,control,and optimization.A complementary technology,Digital Twin(DT),acts as a virtual replica of physical assets or processes,facilitating better decision making through simulations and predictive analytics.CPS and DT underpin the evolution of Industry 4.0 by bridging the physical and digital domains.This survey explores their synergy,highlighting how DT enriches CPS with dynamic modeling,realtime data integration,and advanced simulation capabilities.The layered architecture of DTs within CPS is examined,showcasing the enabling technologies and tools vital for seamless integration.The study addresses key challenges in CPS modeling,such as concurrency and communication,and underscores the importance of DT in overcoming these obstacles.Applications in various sectors are analyzed,including smart manufacturing,healthcare,and urban planning,emphasizing the transformative potential of CPS-DT integration.In addition,the review identifies gaps in existing methodologies and proposes future research directions to develop comprehensive,scalable,and secure CPSDT systems.By synthesizing insights fromthe current literature and presenting a taxonomy of CPS and DT,this survey serves as a foundational reference for academics and practitioners.The findings stress the need for unified frameworks that align CPS and DT with emerging technologies,fostering innovation and efficiency in the digital transformation era.
文摘The management of large-scale architectural engineering projects(e.g.,airports,hospitals)is plagued by information silos,cost overruns,and scheduling delays.While building information modeling(BIM)has improved 3D design coordination,its static nature limits its utility in real-time construction management and operational phases.This paper proposes a novel synergistic framework that integrates the static,deep data of BIM with the dynamic,real-time capabilities of digital twin(DT)technology.The framework establishes a closed-loop data flow from design(BIM)to construction(IoT,drones,BIM 360)to operation(DT platform).We detail the technological stack required,including IoT sensors,cloud computing,and AI-driven analytics.The application of this framework is illustrated through a simulated case study of a mega-terminal airport construction project,demonstrating potential reductions in rework by 15%,improvement in labor productivity by 10%,and enhanced predictive maintenance capabilities.This research contributes to the field of construction engineering by providing a practical model for achieving full lifecycle digitalization and intelligent project management.
基金funded by Big Data Analytics Centre(BIDAC)of United Arab Emirates University under the grant numbers G00003679 and G00004526。
文摘In this paper,we explore the ever-changing field ofDigital Twins(DT)in the Industrial Internet of Things(IIoT)context,emphasizing their critical role in advancing Industry 4.0 toward the frontiers of Industry 5.0.The article explores the applications of DT in several industrial sectors and their smooth integration into the IIoT,focusing on the fundamentals of digital twins and emphasizing the importance of virtual-real integration.It discusses the emergence of DT,contextualizing its evolution within the framework of IIoT.The study categorizes the different types of DT,including prototypes and instances,and provides an in-depth analysis of the enabling technologies such as IoT,Artificial Intelligence(AI),Extended Reality(XR),cloud computing,and the Application Programming Interface(API).The paper demonstrates theDT advantages through the practical integration of real-world case studies,which highlights the technology’s exceptional capacity to improve traceability and fault detection within the context of the IIoT.This paper offers a focused,application-driven perspective on DTs in IIoT,specifically highlighting their role in key production phases such as designing,intelligent manufacturing,maintenance,resource management,automation,security,and safety.By emphasizing their potential to support human-centric,sustainable advancements in Industry 5.0,this study distinguishes itself from existing literature.It provides valuable insights that connect theoretical advancements with practical implementation,making it a crucial resource for researchers,practitioners,and industry professionals.
基金the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.4-Call for tender No. 3138 of 16/12/2021 of Italian Ministry of University and Research funded by the European Union-Next Generation EU. Award Number: Project code CN00000023Concession Decree No. 1033 of 17/06/2022 adopted by the Italian Ministry of University and Research, CUP D93C22000400001, “Sustainable Mobility Center” (CNMS). Spoke 4-Rail Transportation
文摘Predictive maintenance is essential for the implementation of an innovative and efficient structural health monitoring strategy.Models capable of accurately interpreting new data automatically collected by suitably placed sensors to assess the state of the infrastructure represent a fundamental step,particularly for the railway sector,whose safe and continuous operation plays a strategic role in the well-being and development of nations.In this scenario,the benefits of a digital twin of a bonded insu-lated rail joint(IRJ)with the predictive capabilities of advanced classification algorithms based on artificial intelligence have been explored.The digital model provides an accurate mechanical response of the infrastructure as a pair of wheels passes over the joint.As bolt preload conditions vary,four structural health classes were identified for the joint.Two parameters,i.e.gap value and vertical displacement,which are strongly correlated with bolt preload,are used in different combinations to train and test five predictive classifiers.Their classification effectiveness was assessed using several performance indica-tors.Finally,we compared the IRJ condition predictions of two trained classifiers with the available data,confirming their high accuracy.The approach presented provides an interesting solution for future predictive tools in SHM especially in the case of complex systems such as railways where the vehicle-infrastructure interaction is complex and always time varying.
文摘To understand the tensile deformation of electro-deposited Cu with nano-scale twins, a numerical study was carried out based on a conventional theory of mechanism-based strain gradient plasticity （CMSG）. The concept of twin lamella strengthening zone was used in terms of the cohesive interface model to simulate grain-boundary sliding and separation. The model included a number of material parameters, such as grain size, elastic modulus, plastic strain hardening exponent, initial yield stress, as well as twin lamellar distribution, which may contribute to size effects of twin layers in Cu polycrystalline. The results provide information to understand the mechanical behaviors of Cu with nano-scale growth twins.
文摘In order to investigate the dependence of microstructure and mechanical properties on the rolling process parameters, AZ31 magnesium alloy sheets with different grain sizes, basal texture intensities and twinning types were obtained using hot rolling at various temperatures and reductions. The volume fractions of the extension, contraction and secondary twins in the as-rolled sheets depend on the grain size. The highest volume fractions of three types of twins are obtained at 523 K under the reduction of 10% when the average grain size value is the maximum. The critical reductions for complete dynamic recrystallization are 30% at 523 K and 40% at 473 K. The increase of yield strength is ascribed to both grain-refinement strengthening and basal texture strengthening at the first stage. When the grain size does not decrease with increasing the reduction, the yield strength is mainly influenced by the texture weakening.
基金financially supported by the National Key Research and Development Program of China(Grant No.2021YFB3701004)the National Natural Science Foundation of China(Grant Nos.51971054 and 52171055)the Fundamental Research Funds for the Central Universities(N2009006 and N2107007)。
文摘Due to lattice reorientation,grain segmentation,induced recrystallization,twins play a very important role in regulating texture,refining grains,improving mechanical properties and corrosion resistance,and has received more extensive attention.Numerous studies have shown that{10-12}<10-11>tensile twins(TTWs)are easily activated in large quantities due to the lower critical resolve shear stresses(CRSS).Introduction of TTWs under uniaxial compression improved the strength,ductility,and formability of magnesium(Mg)alloys.Moreover,TTWs produced by multi-directional impact forging(MDIF)can optimize the microstructure by dividing grains and promoting recrystallization,resulting in significant improvement of mechanical properties.Although{10-11}<10-12>compressive twins(CTWs)and{10-11}-{10-12}double twins(DTWs)can promote dynamic recrystallization(DRX),they are also favorable nucleation sites for cracks.In addition,the type and volume fraction of twins can affect the corrosion resistance,and they also play different roles in the corrosion process of different Mg alloys.Twins have shown great potential for improving structure and properties,but a comprehensive and critical discussion of twins in Mg alloys is still lacking.Therefore,based on previous studies,this article reviews the common types and variants of twins in Mg alloys,influencing factors,and their effects on the microstructure,mechanical properties and corrosion resistance.In addition,some interesting ideas are being proposed for further research.
