Based on the governing equations and the equivalent models, we propose an equivalent transformation relationships between a plane wave in a one-dimensional medium and a spherical wave in globular geometry with radiall...Based on the governing equations and the equivalent models, we propose an equivalent transformation relationships between a plane wave in a one-dimensional medium and a spherical wave in globular geometry with radially inhomogeneous properties. These equivalent relationships can help us to obtain the analytical solutions of the elastodynamic issues in an inhomogeneous medium. The physical essence of the presented equivalent transformations is the equivalent relationships between the geometry and the material properties. It indicates that the spherical wave problem in globular geometry can be transformed into the plane wave problem in the bar with variable property fields, and its inverse transformation is valid as well. Four different examples of wave motion problems in the inhomogeneous media are solved based on the presented equivalent relationships. We obtain two basic analytical solution forms in Examples I and II, investigate the reflection behavior of inhomogeneous half-space in Example III, and exhibit a special inhomogeneity in Example IV, which can keep the traveling spherical wave in constant amplitude. This study implies that our idea makes solving the associated problem easier.展开更多
In situ observation of electron backscattering diffraction technique was used to evaluate the orientation relationships between austenite and α′-martensite（α′-M） for high manganese transformation-induced plastic...In situ observation of electron backscattering diffraction technique was used to evaluate the orientation relationships between austenite and α′-martensite（α′-M） for high manganese transformation-induced plasticity steel.It was noted that different from the thermal martensite,which well obeyed K-S relationship with austenite,the orientation relationship between deformation-induced α′-M with austenite changed during deformation,namely K-S and N-W relations coexisted.No clear differences existed between α′-M variants with two kinds of relationships in terms of martensitic orientation,shape and the misorientation between α′-M variants.And this phenomenon happened in almost all austenitic grains with different orientations investigated in this study.An atom displacement mechanism through conjugate complex slips of partial dislocations in the distorted fcc lattice was applied in this article to interpret the coexistence of K-S and N-W relationships.展开更多
The orientation relationships（ORs）between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied s...The orientation relationships（ORs）between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction（SAED）as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_（bcc）.A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.展开更多
As the core component of the transformer model,the attention has been proved as all you need in artificial intelligence field in recent years.However,conventional electronic processors are unable to cope with the expo...As the core component of the transformer model,the attention has been proved as all you need in artificial intelligence field in recent years.However,conventional electronic processors are unable to cope with the exponentially increasing hardware costs and energy consumption of the computing-expensive attention.While the photonic neural network(NN)chips provide alternative energy-efficient solutions for accelerating the matrix multiplication(MM),existing photonic accelerators are primarily designed for weight-static NNs that involve MM between the learned weight matrix and input tensors and thus are inefficient in supporting attention mechanisms that require dynamic input operands.Here we propose an attention mechanism relying solely on the runtime-programable optical-interference.Through theoretical analyses,numerical simulations and experimental validations,we demonstrate the photonic“all-interference”attention with learning capability equivalent to classical self-attention,and implement the photonic transformer chip(PTC).Evaluation shows that the PTC is promising to exceed 200 pera-operations per second(POPS)with 1POPS/mm2 computation density and 0.5 POPS/W power efficiency,much better than prior photonic accelerators,and delivers over 200×energy reduction and 2 to 3 orders of magnitude higher computation capability compared to the electronic counterpart.The photonic transformer with“all-interference”attention proposed in this work highlights the immense potential of photonics to construct its own computing paradigm for general purpose machine learning.展开更多
In multiple attribute group decision making （MAGDM） problems based on linguistic information, the granularities of linguistic label sets are usually different due to the differences of thinking modes and habits amon...In multiple attribute group decision making （MAGDM） problems based on linguistic information, the granularities of linguistic label sets are usually different due to the differences of thinking modes and habits among decision makers. In order to deal with this inconvenience, the transformation relationships among multigranular linguistic labels （TRMLLs）, which are applied to unify linguistic labels with different granularities into a certain linguistic label set with fixed granularity, are presented in this paper. Furthermore, the reference tables are made according to TRMLLs so that the interrelated calculation will be less complicated, and the method of how to use them is explained in detail. At length, the TRMLLs are illustrated through an application example.展开更多
基金Scientific Research Fund of Institute of Engineering Mechanics,China Earthquake Administration under Grant No.2017QJGJ06the National Science and Technology Pillar Program under Grant No.2015BAK17B06+2 种基金the Earthquake Industry Special Science Research Foundation Project under Grant No.201508026-02the Fundamental Research Funds for the Central Universities under Grant No.HEUCF170202the program for Innovative Research Team in China Earthquake Administration
文摘Based on the governing equations and the equivalent models, we propose an equivalent transformation relationships between a plane wave in a one-dimensional medium and a spherical wave in globular geometry with radially inhomogeneous properties. These equivalent relationships can help us to obtain the analytical solutions of the elastodynamic issues in an inhomogeneous medium. The physical essence of the presented equivalent transformations is the equivalent relationships between the geometry and the material properties. It indicates that the spherical wave problem in globular geometry can be transformed into the plane wave problem in the bar with variable property fields, and its inverse transformation is valid as well. Four different examples of wave motion problems in the inhomogeneous media are solved based on the presented equivalent relationships. We obtain two basic analytical solution forms in Examples I and II, investigate the reflection behavior of inhomogeneous half-space in Example III, and exhibit a special inhomogeneity in Example IV, which can keep the traveling spherical wave in constant amplitude. This study implies that our idea makes solving the associated problem easier.
基金financially supported by the National Natural Science Foundation of China(No.51271028)
文摘In situ observation of electron backscattering diffraction technique was used to evaluate the orientation relationships between austenite and α′-martensite（α′-M） for high manganese transformation-induced plasticity steel.It was noted that different from the thermal martensite,which well obeyed K-S relationship with austenite,the orientation relationship between deformation-induced α′-M with austenite changed during deformation,namely K-S and N-W relations coexisted.No clear differences existed between α′-M variants with two kinds of relationships in terms of martensitic orientation,shape and the misorientation between α′-M variants.And this phenomenon happened in almost all austenitic grains with different orientations investigated in this study.An atom displacement mechanism through conjugate complex slips of partial dislocations in the distorted fcc lattice was applied in this article to interpret the coexistence of K-S and N-W relationships.
基金financially supported by the National Natural Science Foundation of China (Nos. 51301106 and 51471110)
文摘The orientation relationships（ORs）between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction（SAED）as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_（bcc）.A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.
基金supported by the National Key Research and Development Program of China(2021YFB2801900,2021YFB2801901,2021YFB2801902,2021YFB2801904)National Natural Science Foundation of China(No.61974177)+1 种基金National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(62022062)The Fundamental Research Funds for the Central Universities(QTZX23041).
文摘As the core component of the transformer model,the attention has been proved as all you need in artificial intelligence field in recent years.However,conventional electronic processors are unable to cope with the exponentially increasing hardware costs and energy consumption of the computing-expensive attention.While the photonic neural network(NN)chips provide alternative energy-efficient solutions for accelerating the matrix multiplication(MM),existing photonic accelerators are primarily designed for weight-static NNs that involve MM between the learned weight matrix and input tensors and thus are inefficient in supporting attention mechanisms that require dynamic input operands.Here we propose an attention mechanism relying solely on the runtime-programable optical-interference.Through theoretical analyses,numerical simulations and experimental validations,we demonstrate the photonic“all-interference”attention with learning capability equivalent to classical self-attention,and implement the photonic transformer chip(PTC).Evaluation shows that the PTC is promising to exceed 200 pera-operations per second(POPS)with 1POPS/mm2 computation density and 0.5 POPS/W power efficiency,much better than prior photonic accelerators,and delivers over 200×energy reduction and 2 to 3 orders of magnitude higher computation capability compared to the electronic counterpart.The photonic transformer with“all-interference”attention proposed in this work highlights the immense potential of photonics to construct its own computing paradigm for general purpose machine learning.
基金supported by the National Science Fund for Distinguished Young Scholars of China (No.70625005)
文摘In multiple attribute group decision making （MAGDM） problems based on linguistic information, the granularities of linguistic label sets are usually different due to the differences of thinking modes and habits among decision makers. In order to deal with this inconvenience, the transformation relationships among multigranular linguistic labels （TRMLLs）, which are applied to unify linguistic labels with different granularities into a certain linguistic label set with fixed granularity, are presented in this paper. Furthermore, the reference tables are made according to TRMLLs so that the interrelated calculation will be less complicated, and the method of how to use them is explained in detail. At length, the TRMLLs are illustrated through an application example.
