The exact solutions for the propagation of Love waves in one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)nanoplates with surface effects are derived.An electro-elastic model is developed to investigate the...The exact solutions for the propagation of Love waves in one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)nanoplates with surface effects are derived.An electro-elastic model is developed to investigate the anti-plane strain problem of Love wave propagation.By introducing three shape functions,the wave equations and electric balance equations are decoupled into three uncorrelated problems.Satisfying the boundary conditions of the top surface on the covering layer,the interlayer interface,and the matrix,a dispersive equation with the influence of multi-physical field coupling is provided.A surface PQC model is developed to investigate the surface effects on the propagation behaviors of Love waves in quasicrystal(QC)multilayered structures with nanoscale thicknesses.A novel dispersion relation for the PQC structure is derived in an explicit closed form according to the non-classical mechanical and electric boundary conditions.Numerical examples are given to reveal the effects of the boundary conditions,stacking sequence,characteristic scale,and phason fluctuation characteristics on the dispersion curves of Love waves propagating in PQC nanoplates with surface effects.展开更多
In this paper,we obtain Green’s functions of two-dimensional(2D)piezoelectric quasicrystal(PQC)in half-space and bimaterials.Based on the elastic theory of QCs,the Stroh formalism is used to derive the general soluti...In this paper,we obtain Green’s functions of two-dimensional(2D)piezoelectric quasicrystal(PQC)in half-space and bimaterials.Based on the elastic theory of QCs,the Stroh formalism is used to derive the general solutions of displacements and stresses.Then,we obtain the analytical solutions of half-space and bimaterial Green’s functions.Besides,the interfacial Green’s function for bimaterials is also obtained in the analytical form.Before numerical studies,a comparative study is carried out to validate the present solutions.Typical numerical examples are performed to investigate the effects of multi-physics loadings such as the line force,the line dislocation,the line charge,and the phason line force.As a result,the coupling effect among the phonon field,the phason field,and the electric field is prominent,and the butterfly-shaped contours are characteristic in 2D PQCs.In addition,the changes of material parameters cause variations in physical quantities to a certain degree.展开更多
With the rapid development of quantum computers capable of realizing Shor’s algorithm,existing public key-based algorithms face a significant security risk.Crystals-Kyber has been selected as the only key encapsulati...With the rapid development of quantum computers capable of realizing Shor’s algorithm,existing public key-based algorithms face a significant security risk.Crystals-Kyber has been selected as the only key encapsulation mechanism(KEM)algorithm in the National Institute of Standards and Technology(NIST)Post-Quantum Cryptography(PQC)competition.In this study,we present a portable and efficient implementation of a Crystals-Kyber post-quantum KEM based on WebAssembly(Wasm),a recently released portable execution framework for high-performance web applications.Until now,most Kyber implementations have been developed with native programming languages such as C and Assembly.Although there are a few previous Kyber implementations based on JavaScript for portability,their performance is significantly lower than that of implementations based on native programming languages.Therefore,it is necessary to develop a portable and efficient Kyber implementation to secure web applications in the quantum computing era.Our Kyber software is based on JavaScript and Wasm to provide portability and efficiency while ensuring quantum security.Namely,the overall software is written in JavaScript,and the performance core parts(secure hash algorithm-3-based operations and polynomial multiplication)are written in Wasm.Furthermore,we parallelize the number theoretic transform(NTT)-based polynomial multiplication using single instruction multiple data(SIMD)functionality,which is available in Wasm.The three steps in the NTT-based polynomial multiplication have been parallelized with Wasm SIMD intrinsic functions.Our software outperforms the latest reference implementation of Kyber developed in JavaScript by×4.02(resp.×4.32 and×4.1),×3.42(resp.×3.52 and×3.44),and×3.41(resp.×3.44 and×3.38)in terms of key generation,encapsulation,and decapsulation on Google Chrome(resp.Firefox,and Microsoft Edge).As far as we know,this is the first software implementation of Kyber with Wasm technology in the web environment.展开更多
This research paper analyzes the urgent topic of quantum cybersecurity and the current federal quantum-cyber landscape. Quantum-safe implementations within existing and future Internet of Things infrastructure are dis...This research paper analyzes the urgent topic of quantum cybersecurity and the current federal quantum-cyber landscape. Quantum-safe implementations within existing and future Internet of Things infrastructure are discussed, along with quantum vulnerabilities in public key infrastructure and symmetric cryptographic algorithms. Other relevant non-encryption-specific areas within cybersecurity are similarly raised. The evolution and expansion of cyberwarfare as well as new developments in cyber defense beyond post-quantum cryptography and quantum key distribution are subsequently explored, with an emphasis on public and private sector awareness and vigilance in maintaining strong security posture.展开更多
To effectively reduce the field concentration around a hole or crack,an anti-plane shear problem of a nano-elliptical hole or a nano-crack pasting a reinforcement layer in a one-dimensional(1D)hexagonal piezoelectric ...To effectively reduce the field concentration around a hole or crack,an anti-plane shear problem of a nano-elliptical hole or a nano-crack pasting a reinforcement layer in a one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)is investigated subject to remotely mechanical and electrical loadings.The surface effect and dielectric characteristics inside the hole are considered for actuality.By utilizing the technique of conformal mapping and the complex variable method,the phonon stresses,phason stresses,and electric displacements in the matrix and reinforcement layer are exactly derived under both electrically permeable and impermeable boundary conditions.Three size-dependent field intensity factors near the nano-crack tip are further obtained when the nano-elliptical hole is reduced to the nano-crack.Numerical examples are illustrated to show the effects of material properties of the surface layer and reinforced layer,the aspect ratio of the hole,and the thickness of the reinforcing layer on the field concentration of the nano-elliptical hole and the field intensity factors near the nano-crack tip.The results indicate that the properties of the surface layer and reinforcement layer and the electrical boundary conditions have great effects on the field concentration of the nano-hole and nano-crack,which are useful for optimizing and designing the microdevices by PQC nanocomposites in engineering practice.展开更多
The response-spectrum mode superposition method is widely used for seismic response analyses of linear systems. In using this method, the complete quadratic combination (CQC) is adopted for classically damped linear...The response-spectrum mode superposition method is widely used for seismic response analyses of linear systems. In using this method, the complete quadratic combination (CQC) is adopted for classically damped linear systems and the complex complete quadratic combination (CCQC) formula is adopted for non-classically damped linear systems. However, in both cases, the calculation of seismic response analyses is very time consuming. In this paper, the variation of the modal correlation coefficients of displacement, velocity and displacement-velocity with frequency and damping ratios of two modes of interest are studied, Moreover, the calculation errors generated by using CQC and square-root-of-the-sum-of-thesquares (SRSS) methods (or CCQC and CSRSS methods) for different damping combinations are compared. In these analyses, some boundary lines for classically and non-classically damped systems are plotted to distinguish the allowed minimum frequency ratio at given geometric mean of the damping ratios of both modes if their relativity is neglected. Furthermore, the simplified method, which is a special mode quadratic combination method considering only relativity of adjacent modes in CQC method and named simplified CQC or partial quadratic combination (PQC) method for classically damped linear system, is proposed to improve computational efficiency, and the criterion for determination of how many correlated modes should be adopted is proposed. Similarly, the simplified CCQC or complex partial quadratic combination (CPQC) method for the non-classically damped linear system and the corresponding criterion are also deduced. Finally, a numerical example is given to illustrate the applicability, computational accuracy and efficiency of the PQC and CPQC methods.展开更多
A three-phase confocal elliptical cylinder model is proposed to analyze micromechanics of one-dimensional hexagonal piezoelectric quasicrystal (PQC) compos- ites. Exact solutions of the phonon, phason, and electric ...A three-phase confocal elliptical cylinder model is proposed to analyze micromechanics of one-dimensional hexagonal piezoelectric quasicrystal (PQC) compos- ites. Exact solutions of the phonon, phason, and electric fields are obtained by using the conformal mapping combined with the Laurent expansion technique when the model is subject to far-field anti-plane mechanical and in-plane electric loadings. The effective elec- troelastic constants of several different composites made up of PQC, quasicrystal (QC), and piezoelectric (PE) materials are predicted by the generalized self-consistent method. Numerical examples are conducted to show the effects of the volume fraction and the cross-sectional shape of inclusion (or fiber) on the effective electroelastic constants of these composites. Compared with other micromechanical methods, the generalized self- consistent and Mori-Tanaka methods can predict the effective electroelastic constants of the composites consistently.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.12272402 and11972365)the China Agricultural University Education Foundation(No.1101-2412001)。
文摘The exact solutions for the propagation of Love waves in one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)nanoplates with surface effects are derived.An electro-elastic model is developed to investigate the anti-plane strain problem of Love wave propagation.By introducing three shape functions,the wave equations and electric balance equations are decoupled into three uncorrelated problems.Satisfying the boundary conditions of the top surface on the covering layer,the interlayer interface,and the matrix,a dispersive equation with the influence of multi-physical field coupling is provided.A surface PQC model is developed to investigate the surface effects on the propagation behaviors of Love waves in quasicrystal(QC)multilayered structures with nanoscale thicknesses.A novel dispersion relation for the PQC structure is derived in an explicit closed form according to the non-classical mechanical and electric boundary conditions.Numerical examples are given to reveal the effects of the boundary conditions,stacking sequence,characteristic scale,and phason fluctuation characteristics on the dispersion curves of Love waves propagating in PQC nanoplates with surface effects.
基金This work is partly financed via National Key Research and Development Program of China(2020AAA0107700)National Natural Science Foundation of China(62227805,62072398)+6 种基金SUTD-ZJU IDEA Grant for visiting professors(SUTD-ZJUVP201901)Alibaba-Zhejiang University Joint Institute of Frontier TechnologiesNational Key Laboratory of Science and Technology on Information System Security(6142111210301)State Key Laboratory of Mathematical Engineering and Advanced ComputingKey Laboratory of Cyberspace Situation Awareness of Henan Province(HNTS2022001)RISQ(http://risq.fr/)PIA ProjectBRAINE Project from European Union’s Horizon 2020/ECSEL research and innovation program(N◦876967)。
基金the National Natural Science Foundation of China(Nos.11972365 and 12102458)。
文摘In this paper,we obtain Green’s functions of two-dimensional(2D)piezoelectric quasicrystal(PQC)in half-space and bimaterials.Based on the elastic theory of QCs,the Stroh formalism is used to derive the general solutions of displacements and stresses.Then,we obtain the analytical solutions of half-space and bimaterial Green’s functions.Besides,the interfacial Green’s function for bimaterials is also obtained in the analytical form.Before numerical studies,a comparative study is carried out to validate the present solutions.Typical numerical examples are performed to investigate the effects of multi-physics loadings such as the line force,the line dislocation,the line charge,and the phason line force.As a result,the coupling effect among the phonon field,the phason field,and the electric field is prominent,and the butterfly-shaped contours are characteristic in 2D PQCs.In addition,the changes of material parameters cause variations in physical quantities to a certain degree.
基金This work was supported by Institute of Information&communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(No.2022-0-01019,Development of eSIM security platform technology for edge devices to expand the eSIM ecosystem)This was partly supported by the MSIT(Ministry of Science and ICT)Korea,under the ITRC(Information Technology Research Center)support program(IITP-2022-RS-2022-00164800)supervised by the IITP(Institute for Information&Communications Technology Planning&Evaluation).
文摘With the rapid development of quantum computers capable of realizing Shor’s algorithm,existing public key-based algorithms face a significant security risk.Crystals-Kyber has been selected as the only key encapsulation mechanism(KEM)algorithm in the National Institute of Standards and Technology(NIST)Post-Quantum Cryptography(PQC)competition.In this study,we present a portable and efficient implementation of a Crystals-Kyber post-quantum KEM based on WebAssembly(Wasm),a recently released portable execution framework for high-performance web applications.Until now,most Kyber implementations have been developed with native programming languages such as C and Assembly.Although there are a few previous Kyber implementations based on JavaScript for portability,their performance is significantly lower than that of implementations based on native programming languages.Therefore,it is necessary to develop a portable and efficient Kyber implementation to secure web applications in the quantum computing era.Our Kyber software is based on JavaScript and Wasm to provide portability and efficiency while ensuring quantum security.Namely,the overall software is written in JavaScript,and the performance core parts(secure hash algorithm-3-based operations and polynomial multiplication)are written in Wasm.Furthermore,we parallelize the number theoretic transform(NTT)-based polynomial multiplication using single instruction multiple data(SIMD)functionality,which is available in Wasm.The three steps in the NTT-based polynomial multiplication have been parallelized with Wasm SIMD intrinsic functions.Our software outperforms the latest reference implementation of Kyber developed in JavaScript by×4.02(resp.×4.32 and×4.1),×3.42(resp.×3.52 and×3.44),and×3.41(resp.×3.44 and×3.38)in terms of key generation,encapsulation,and decapsulation on Google Chrome(resp.Firefox,and Microsoft Edge).As far as we know,this is the first software implementation of Kyber with Wasm technology in the web environment.
文摘This research paper analyzes the urgent topic of quantum cybersecurity and the current federal quantum-cyber landscape. Quantum-safe implementations within existing and future Internet of Things infrastructure are discussed, along with quantum vulnerabilities in public key infrastructure and symmetric cryptographic algorithms. Other relevant non-encryption-specific areas within cybersecurity are similarly raised. The evolution and expansion of cyberwarfare as well as new developments in cyber defense beyond post-quantum cryptography and quantum key distribution are subsequently explored, with an emphasis on public and private sector awareness and vigilance in maintaining strong security posture.
基金supported by the National Natural Science Foundation of China(Nos.12072166,11862021)the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(No.NJYT-19-A06)the Natural Science Foundation of Inner Mongolia Autonomous Region of China(No.2020MS01006)。
文摘To effectively reduce the field concentration around a hole or crack,an anti-plane shear problem of a nano-elliptical hole or a nano-crack pasting a reinforcement layer in a one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)is investigated subject to remotely mechanical and electrical loadings.The surface effect and dielectric characteristics inside the hole are considered for actuality.By utilizing the technique of conformal mapping and the complex variable method,the phonon stresses,phason stresses,and electric displacements in the matrix and reinforcement layer are exactly derived under both electrically permeable and impermeable boundary conditions.Three size-dependent field intensity factors near the nano-crack tip are further obtained when the nano-elliptical hole is reduced to the nano-crack.Numerical examples are illustrated to show the effects of material properties of the surface layer and reinforced layer,the aspect ratio of the hole,and the thickness of the reinforcing layer on the field concentration of the nano-elliptical hole and the field intensity factors near the nano-crack tip.The results indicate that the properties of the surface layer and reinforcement layer and the electrical boundary conditions have great effects on the field concentration of the nano-hole and nano-crack,which are useful for optimizing and designing the microdevices by PQC nanocomposites in engineering practice.
基金National Natural science Foundation of China Under Grant No. 50178007 and No.50408005
文摘The response-spectrum mode superposition method is widely used for seismic response analyses of linear systems. In using this method, the complete quadratic combination (CQC) is adopted for classically damped linear systems and the complex complete quadratic combination (CCQC) formula is adopted for non-classically damped linear systems. However, in both cases, the calculation of seismic response analyses is very time consuming. In this paper, the variation of the modal correlation coefficients of displacement, velocity and displacement-velocity with frequency and damping ratios of two modes of interest are studied, Moreover, the calculation errors generated by using CQC and square-root-of-the-sum-of-thesquares (SRSS) methods (or CCQC and CSRSS methods) for different damping combinations are compared. In these analyses, some boundary lines for classically and non-classically damped systems are plotted to distinguish the allowed minimum frequency ratio at given geometric mean of the damping ratios of both modes if their relativity is neglected. Furthermore, the simplified method, which is a special mode quadratic combination method considering only relativity of adjacent modes in CQC method and named simplified CQC or partial quadratic combination (PQC) method for classically damped linear system, is proposed to improve computational efficiency, and the criterion for determination of how many correlated modes should be adopted is proposed. Similarly, the simplified CCQC or complex partial quadratic combination (CPQC) method for the non-classically damped linear system and the corresponding criterion are also deduced. Finally, a numerical example is given to illustrate the applicability, computational accuracy and efficiency of the PQC and CPQC methods.
基金Projected supported by the National Natural Science Foundation of China(Nos.11502123 and11262012)the Natural Science Foundation of Inner Mongolia Autonomous Region of China(No.2015JQ01)
文摘A three-phase confocal elliptical cylinder model is proposed to analyze micromechanics of one-dimensional hexagonal piezoelectric quasicrystal (PQC) compos- ites. Exact solutions of the phonon, phason, and electric fields are obtained by using the conformal mapping combined with the Laurent expansion technique when the model is subject to far-field anti-plane mechanical and in-plane electric loadings. The effective elec- troelastic constants of several different composites made up of PQC, quasicrystal (QC), and piezoelectric (PE) materials are predicted by the generalized self-consistent method. Numerical examples are conducted to show the effects of the volume fraction and the cross-sectional shape of inclusion (or fiber) on the effective electroelastic constants of these composites. Compared with other micromechanical methods, the generalized self- consistent and Mori-Tanaka methods can predict the effective electroelastic constants of the composites consistently.