Beta Ti−35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing(AM)to achieve a balance between light weight and high strength.The impact of reinforc...Beta Ti−35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing(AM)to achieve a balance between light weight and high strength.The impact of reinforcing layers on the compressive deformation behavior of porous composites was investigated through micro-computed tomography(Micro-CT)and finite element method(FEM)analyses.The results indicate that the addition of reinforcement layers to sandwich structures can significantly enhance the compressive yield strength and energy absorption capacity of porous metal structures;Micro-CT in-situ observation shows that the strain of the porous structure without the reinforcing layer is concentrated in the middle region,while the strain of the porous structure with the reinforcing layer is uniformly distributed;FEM analysis reveals that the reinforcing layers can alter stress distribution and reduce stress concentration,thereby promoting uniform deformation of the porous structure.The addition of reinforcing layer increases the compressive yield strength of sandwich-structured composite materials by 124%under the condition of limited reduction of porosity,and the yield strength increases from 4.6 to 10.3 MPa.展开更多
互联网的普及对计算范式的发展产生了重大影响。随着新一代信息技术基础设施的不断完善,学术界与工业界在持续探索新的计算范式,以实现对算力的充分挖掘。海量物联网(internet of things,IoT)设备产生的庞大数据逐渐超出了以云服务器为...互联网的普及对计算范式的发展产生了重大影响。随着新一代信息技术基础设施的不断完善,学术界与工业界在持续探索新的计算范式,以实现对算力的充分挖掘。海量物联网(internet of things,IoT)设备产生的庞大数据逐渐超出了以云服务器为代表的高性能后端的处理能力,边缘计算(edge computing)通过云边端协同缓解了这一问题,但仍存在算力利用率低、算/存容错性低,以及计算资源整合度低等困难与挑战。元计算(meta computing)是一种新型计算范式,旨在零信任基础上,打破算力藩篱,整合网络中所有的可用计算与存储资源,为各项任务提供高效、安全可靠、可容错的个性化服务,同时利用密码学技术保护敏感数据信息,确保用户数据的隐私性,保证任务结果的准确性与可靠性,最终实现“对任何一个人或者一项任务整个网络就是一台计算机”,即“网络即计算机(network-as-a-computer,NaaC)”,也称为“元计算机”(meta computer)。本文分析了元计算的三大功能目标,据此提出了一个包含云边端资源、设备管理与零信任计算管理模块的元计算机架构。在该架构中,设备管理模块将海量异构设备的资源抽象为可以自由操控的对象,零信任计算管理模块则根据用户任务需求直接调度计算资源,完成强容错的计算任务并输出可验证的计算结果,最后进行结算。本文在剖析元计算机架构与功能特性的基础上,分析了实现元计算机面临的技术挑战,给出了元计算“从局部过渡到整体”的发展思路,预测了元计算的未来应用场景,为未来元计算的落地与发展规划出合理的突破路线。展开更多
To estimate the geometric characteristics, especially wet areas and section areas, of three dimensional numerical conceptual aircraft models, a method based on surface elements is proposed. On the premise that numerou...To estimate the geometric characteristics, especially wet areas and section areas, of three dimensional numerical conceptual aircraft models, a method based on surface elements is proposed. On the premise that numerous surface elements are generated to represent each component surface, a component wet area of the surface is estimated by adding up the areas of such elements that are not covered by any other component surfaces. The elements are also used to get the section polygons of such composite surfaces as the whole aircraft at a given body station, then a section area is approximated with the sum of trapezoidal areas between such sides of polygons that are not covered by any other component and a reference axis. Practical application to a computer aided aircraft conceptual design system shows that the methed is applicable to different kinds of conceptual aircraft models and its precision is satisfying to the conceptual design.展开更多
The paper starts with a brief overview to the necessity of sheet metal forming simulation and the complexity of automobile panel forming, then leads to finite element analysis (FEA) which is a powerful simulation too...The paper starts with a brief overview to the necessity of sheet metal forming simulation and the complexity of automobile panel forming, then leads to finite element analysis (FEA) which is a powerful simulation tool for analyzing complex three-dimensional sheet metal forming problems. The theory and features of the dynamic explicit finite element methods are introduced and the available various commercial finite element method codes used for sheet metal forming simulation in the world are discussed,and the civil and international status quo of automobile panel simulation as well. The front door outer panel of one certain new automobile is regarded as one example that the dynamic explicit FEM code Dynaform is used for the simulation of the front door outer panel forming process. Process defects such as ruptures are predicted. The improving methods can be given according to the simulation results. Foreground of sheet metal forming simulation is outlined.展开更多
Flexoelectric-induced voltage shift in a weak anchoring hybrid aligned nematic fiquid crystai cell is investigated theoretically. Based on the elastic theory of liquid crystal and the variation method, the equations f...Flexoelectric-induced voltage shift in a weak anchoring hybrid aligned nematic fiquid crystai cell is investigated theoretically. Based on the elastic theory of liquid crystal and the variation method, the equations for the bulk and the boundary of the cell are derived. By computer simulation, the dependence of the shift voltage on the sum of the ttexoelectric coefficients and the anchoring energy strength is obtained. As a result, a novel method to determine the sum of the flexoelectric coefficients by measuring the shift voltage is put forward.展开更多
A new approach of relation extraction is described in this paper. It adopts a bootstrap- ping model with a novel iteration strategy, which generates more precise examples of specific relation. Compared with previous m...A new approach of relation extraction is described in this paper. It adopts a bootstrap- ping model with a novel iteration strategy, which generates more precise examples of specific relation. Compared with previous methods, the proposed method has three main advantages: first, it needs less manual intervention; second, more abundant and reasonable information are introduced to represent a relation pattern; third, it reduces the risk of circular dependency occurrence in bootstrapping. Scalable evaluation methodology and metrics are developed for our task with comparable techniques over TianWang 100G corpus. The experimental results show that it can get 90% precision and have excellent expansibility.展开更多
A software component must be tested every time it is reused in order to assure quality of component itself and system in which it is to be integrated.So how to increase testability of component has become a key techno...A software component must be tested every time it is reused in order to assure quality of component itself and system in which it is to be integrated.So how to increase testability of component has become a key technology in the software engineering community.Here a method is introduced to increase component testability.And meanings of component testability and relative effective ways to increase testability are summarized.Then definitions of component coupling testing criterion,DU-I(Definition-Use Information) and OP-Vs(Observation-Point Values)are given.Base on these,a definition-use table is introduced,which includes DU-A and OP-Vs item,to help component testers to understand and observe interior details about component under test better.Then a framework of testable component based on above DU-table is given.These facilities provide ways to detect errors,observe state variables by observation-points based monitor mechanism.Moreover,above methods are applied to our application developed by ourselves before,and some test cases are generated.Then our method is compared with Orso method and Kan method using the same example,presenting the comparison results.The results illustrate the validity of our method,effectively generating test cases and killing more mutants.展开更多
Recently, solutions to inverse problems have been required in various engineering fields. The neural network inversion method has been studied as one of the neural network-based solutions. On the other hand, the exten...Recently, solutions to inverse problems have been required in various engineering fields. The neural network inversion method has been studied as one of the neural network-based solutions. On the other hand, the extension of the neural network to a higher-dimensional domain, e.g., complex-value or quaternion, has been proposed, and a number of higher-dimensional neural network models have been proposed. Using the quatemion, we have the advantage of expressing 3D (three-dimensional) object attitudes easily. In the quaternion domain, we can define inverse problems where the cause and the result are expressed by the quaternion. In this paper, we extend the neural network inversion method to the quatemion domain. Further, we provide the results of the computer experiments to demonstrate the process and effectiveness of our method.展开更多
Objective:To investigate the role of ^(99m)Tc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathicParkinson's disease(PD).Methods:Thirty-eight patients with primary,tentative diagnosis of PD and eighte...Objective:To investigate the role of ^(99m)Tc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathicParkinson's disease(PD).Methods:Thirty-eight patients with primary,tentative diagnosis of PD and eighteen age-matchednormal controls were studied with ^(99m)Tc-TRODAT-1 SPECT imaging.The regions of interests(ROIs)were drawn manually oncerebellum(CB),occipital cortex(OC)and three transverse plane slice-views of striatums,the semiquantitative BG(back-ground)/[(OC+CB)/2]were then calculated.Results:A lower uptake of ^(99m)Tc-TRODAT-1 in striatums were displayed inthirty-six out of thirty-eight PD patients by visual inspection,compared to controls.In twenty-four PD cases with HYS(Hoehn andYahr scale)stage Ⅰ,a greater loss of DAT uptake was found in striatum and its subregions contralateral striatum to the affectedlimbs than in the same regions of the controls,although the striatal uptake was bilaterally reduced.Using Spearman correlationanalysis showed that the reduction of the uptake ratios significantly correlated with the UPDRS in striatum and all its subregions inthe PD group(P<0.05),a similar change was also found in the putamen by using the rating scale of Hoehn and Yahr (P<0.05).However,analysis of variance(ANOVA)did not show any relationship between the decreasing uptake of ^(99m)Tc-TRODAT-1 andincreasing severity of PD patients,although the specific uptake of ^(99m)Tc-TRODAT-1 was continuously decreased in the striatumby visual inspection with the progress of PD from HYS stage Ⅰ to Ⅲ.Conclusion:^(99m)Tc-TRODAT-1 SPECT imaging may serve asa useful method for improving the correct diagnosis of PD.In assessing the role of ^(99m)Tc-TRODAT-1 SPECT in disease severity ofPD,UPDRS can offer a comprehensive index,although the Hoehn and Yahr assessment may be available in part.展开更多
In order to realize the computer aided design of AT shifting element schemes, a mathematical model of shifting element schemes which can be easily identified by computers was built. Taking the transmission ratio seque...In order to realize the computer aided design of AT shifting element schemes, a mathematical model of shifting element schemes which can be easily identified by computers was built. Taking the transmission ratio sequence as an optimization objective and simple shifting logic between adjacent gears through operating only one shifting element as a constraint condition, a fitness function of shifting element schemes was proposed. ZF-8AT shifting element schemes were optimized based on GA work-box of MATLAB, and the feasibility of the optimization algorithm was verified.展开更多
Shape optimization of mechanical components is one of the issues that have been considered in recent years. Different methods were presented such as adaptive biological for reducing costs and increasing accuracy. The ...Shape optimization of mechanical components is one of the issues that have been considered in recent years. Different methods were presented such as adaptive biological for reducing costs and increasing accuracy. The effects of step factor, the number of control points and the definition way of control points coordinates in convergence rate were studied. A code was written using ANSYS Parametric Design Language (APDL) which receives the studied parameters as input and obtains the optimum shape for the components. The results show that for achieving successful optimization, step factor should be in a specific range. It is found that the use of any coordinate system in defining control points coordinates and selection of any direction for stimulus vector of algorithm will also result in optimum shape. Furthermore, by increasing the number of control points, some non-uniformities are created in the studied boundary. Achieving acceptable accuracy seems impossible due to the creation of saw form at the studied boundary which is called "saw position".展开更多
A proposal for smooth aggressive location restoration by forwarding pointer is given in this paper. A mobile communication system's robustness in case of a location-database failure is improved without the need for p...A proposal for smooth aggressive location restoration by forwarding pointer is given in this paper. A mobile communication system's robustness in case of a location-database failure is improved without the need for periodic location update operations. Radio resources would be saved at the cost of wire signal and operation of location databases. Meanwhile, a chain of forwarding location pointers has been used during the period of HLR failure. So mobile stations are unconscious of the failure of HLR, and mobile subscribers can always make outgoing call.展开更多
The main objective of this work was the construction of a Multidisciplinary Learning Object as a tool for teaching, enabling the use of information and communication technologies for use by teachers acting in elementa...The main objective of this work was the construction of a Multidisciplinary Learning Object as a tool for teaching, enabling the use of information and communication technologies for use by teachers acting in elementary school, based on Discourse Analysis, Theory Cybernetic-systemic, the Multiple Intelligences and Collaborative Learning. All of them are informed by Foucault, Pecheux, Bakhtin, Gardner, Levy, and others. The theoretical contribution is justified to the extent that the student is above all a being inserted into a user company tool created by it over time, to act on the world. Theoretical principles underlying the construction of learning objects as tools for teaching are related to teaching and learning. The developed learning object establishes the link between the fields of pedagogy and usability, the step by step construction of each of them and their purposes, characteristics, and all detailed in the development of research. The construction of the learning object follows the steps of a methodological construction for the development of a computerized product, followed by a systematic planning and the design and construction.展开更多
In this paper, used BSO(Bi12SiO(20)) crystal as a hologram recording material,TV-camera as a detector, and a holographic setup controlled by a computer, automatically calculating hologram of 3-interferograms method ...In this paper, used BSO(Bi12SiO(20)) crystal as a hologram recording material,TV-camera as a detector, and a holographic setup controlled by a computer, automatically calculating hologram of 3-interferograms method is theoretically and experimentally studied. This new holographic recording material and automatically calculating hologram make it possible to use real-time holography in an industry. As a practical example, the shrinking of 2-components adhesive in 4 h is measured.展开更多
基金the Hunan Young Scientific Innovative Talents Program,China(No.2020RC3040)Outstanding Youth Fund of Hunan Natural Science Foundation,China(Nos.2021JJ20011,2021JJ40600,2021JJ40590)the National Natural Science Foundation of China(Nos.52001030,52204371)..
文摘Beta Ti−35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing(AM)to achieve a balance between light weight and high strength.The impact of reinforcing layers on the compressive deformation behavior of porous composites was investigated through micro-computed tomography(Micro-CT)and finite element method(FEM)analyses.The results indicate that the addition of reinforcement layers to sandwich structures can significantly enhance the compressive yield strength and energy absorption capacity of porous metal structures;Micro-CT in-situ observation shows that the strain of the porous structure without the reinforcing layer is concentrated in the middle region,while the strain of the porous structure with the reinforcing layer is uniformly distributed;FEM analysis reveals that the reinforcing layers can alter stress distribution and reduce stress concentration,thereby promoting uniform deformation of the porous structure.The addition of reinforcing layer increases the compressive yield strength of sandwich-structured composite materials by 124%under the condition of limited reduction of porosity,and the yield strength increases from 4.6 to 10.3 MPa.
文摘To estimate the geometric characteristics, especially wet areas and section areas, of three dimensional numerical conceptual aircraft models, a method based on surface elements is proposed. On the premise that numerous surface elements are generated to represent each component surface, a component wet area of the surface is estimated by adding up the areas of such elements that are not covered by any other component surfaces. The elements are also used to get the section polygons of such composite surfaces as the whole aircraft at a given body station, then a section area is approximated with the sum of trapezoidal areas between such sides of polygons that are not covered by any other component and a reference axis. Practical application to a computer aided aircraft conceptual design system shows that the methed is applicable to different kinds of conceptual aircraft models and its precision is satisfying to the conceptual design.
文摘The paper starts with a brief overview to the necessity of sheet metal forming simulation and the complexity of automobile panel forming, then leads to finite element analysis (FEA) which is a powerful simulation tool for analyzing complex three-dimensional sheet metal forming problems. The theory and features of the dynamic explicit finite element methods are introduced and the available various commercial finite element method codes used for sheet metal forming simulation in the world are discussed,and the civil and international status quo of automobile panel simulation as well. The front door outer panel of one certain new automobile is regarded as one example that the dynamic explicit FEM code Dynaform is used for the simulation of the front door outer panel forming process. Process defects such as ruptures are predicted. The improving methods can be given according to the simulation results. Foreground of sheet metal forming simulation is outlined.
基金Supported by the Natural Science Foundation of Hebei Province under Grant No. A2010000004the National Natural Science Foundation of China under Grant No. 60736042+1 种基金the Key Subject Construction Project of Hebei Province Universitythe Research Project of Hebei Education Department under Grant No. Z2011133
文摘Flexoelectric-induced voltage shift in a weak anchoring hybrid aligned nematic fiquid crystai cell is investigated theoretically. Based on the elastic theory of liquid crystal and the variation method, the equations for the bulk and the boundary of the cell are derived. By computer simulation, the dependence of the shift voltage on the sum of the ttexoelectric coefficients and the anchoring energy strength is obtained. As a result, a novel method to determine the sum of the flexoelectric coefficients by measuring the shift voltage is put forward.
基金Supported by the National Natural Science Foundation of China (No.60503072, No.60575042 and No.60435020).
文摘A new approach of relation extraction is described in this paper. It adopts a bootstrap- ping model with a novel iteration strategy, which generates more precise examples of specific relation. Compared with previous methods, the proposed method has three main advantages: first, it needs less manual intervention; second, more abundant and reasonable information are introduced to represent a relation pattern; third, it reduces the risk of circular dependency occurrence in bootstrapping. Scalable evaluation methodology and metrics are developed for our task with comparable techniques over TianWang 100G corpus. The experimental results show that it can get 90% precision and have excellent expansibility.
基金Natural Science Fund of Hubei Province (No2005ABA266)
文摘A software component must be tested every time it is reused in order to assure quality of component itself and system in which it is to be integrated.So how to increase testability of component has become a key technology in the software engineering community.Here a method is introduced to increase component testability.And meanings of component testability and relative effective ways to increase testability are summarized.Then definitions of component coupling testing criterion,DU-I(Definition-Use Information) and OP-Vs(Observation-Point Values)are given.Base on these,a definition-use table is introduced,which includes DU-A and OP-Vs item,to help component testers to understand and observe interior details about component under test better.Then a framework of testable component based on above DU-table is given.These facilities provide ways to detect errors,observe state variables by observation-points based monitor mechanism.Moreover,above methods are applied to our application developed by ourselves before,and some test cases are generated.Then our method is compared with Orso method and Kan method using the same example,presenting the comparison results.The results illustrate the validity of our method,effectively generating test cases and killing more mutants.
文摘Recently, solutions to inverse problems have been required in various engineering fields. The neural network inversion method has been studied as one of the neural network-based solutions. On the other hand, the extension of the neural network to a higher-dimensional domain, e.g., complex-value or quaternion, has been proposed, and a number of higher-dimensional neural network models have been proposed. Using the quatemion, we have the advantage of expressing 3D (three-dimensional) object attitudes easily. In the quaternion domain, we can define inverse problems where the cause and the result are expressed by the quaternion. In this paper, we extend the neural network inversion method to the quatemion domain. Further, we provide the results of the computer experiments to demonstrate the process and effectiveness of our method.
文摘Objective:To investigate the role of ^(99m)Tc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathicParkinson's disease(PD).Methods:Thirty-eight patients with primary,tentative diagnosis of PD and eighteen age-matchednormal controls were studied with ^(99m)Tc-TRODAT-1 SPECT imaging.The regions of interests(ROIs)were drawn manually oncerebellum(CB),occipital cortex(OC)and three transverse plane slice-views of striatums,the semiquantitative BG(back-ground)/[(OC+CB)/2]were then calculated.Results:A lower uptake of ^(99m)Tc-TRODAT-1 in striatums were displayed inthirty-six out of thirty-eight PD patients by visual inspection,compared to controls.In twenty-four PD cases with HYS(Hoehn andYahr scale)stage Ⅰ,a greater loss of DAT uptake was found in striatum and its subregions contralateral striatum to the affectedlimbs than in the same regions of the controls,although the striatal uptake was bilaterally reduced.Using Spearman correlationanalysis showed that the reduction of the uptake ratios significantly correlated with the UPDRS in striatum and all its subregions inthe PD group(P<0.05),a similar change was also found in the putamen by using the rating scale of Hoehn and Yahr (P<0.05).However,analysis of variance(ANOVA)did not show any relationship between the decreasing uptake of ^(99m)Tc-TRODAT-1 andincreasing severity of PD patients,although the specific uptake of ^(99m)Tc-TRODAT-1 was continuously decreased in the striatumby visual inspection with the progress of PD from HYS stage Ⅰ to Ⅲ.Conclusion:^(99m)Tc-TRODAT-1 SPECT imaging may serve asa useful method for improving the correct diagnosis of PD.In assessing the role of ^(99m)Tc-TRODAT-1 SPECT in disease severity ofPD,UPDRS can offer a comprehensive index,although the Hoehn and Yahr assessment may be available in part.
基金Project(2011BAG09B00)supported by the National Science and Technology Support Program,China
文摘In order to realize the computer aided design of AT shifting element schemes, a mathematical model of shifting element schemes which can be easily identified by computers was built. Taking the transmission ratio sequence as an optimization objective and simple shifting logic between adjacent gears through operating only one shifting element as a constraint condition, a fitness function of shifting element schemes was proposed. ZF-8AT shifting element schemes were optimized based on GA work-box of MATLAB, and the feasibility of the optimization algorithm was verified.
文摘Shape optimization of mechanical components is one of the issues that have been considered in recent years. Different methods were presented such as adaptive biological for reducing costs and increasing accuracy. The effects of step factor, the number of control points and the definition way of control points coordinates in convergence rate were studied. A code was written using ANSYS Parametric Design Language (APDL) which receives the studied parameters as input and obtains the optimum shape for the components. The results show that for achieving successful optimization, step factor should be in a specific range. It is found that the use of any coordinate system in defining control points coordinates and selection of any direction for stimulus vector of algorithm will also result in optimum shape. Furthermore, by increasing the number of control points, some non-uniformities are created in the studied boundary. Achieving acceptable accuracy seems impossible due to the creation of saw form at the studied boundary which is called "saw position".
文摘A proposal for smooth aggressive location restoration by forwarding pointer is given in this paper. A mobile communication system's robustness in case of a location-database failure is improved without the need for periodic location update operations. Radio resources would be saved at the cost of wire signal and operation of location databases. Meanwhile, a chain of forwarding location pointers has been used during the period of HLR failure. So mobile stations are unconscious of the failure of HLR, and mobile subscribers can always make outgoing call.
文摘The main objective of this work was the construction of a Multidisciplinary Learning Object as a tool for teaching, enabling the use of information and communication technologies for use by teachers acting in elementary school, based on Discourse Analysis, Theory Cybernetic-systemic, the Multiple Intelligences and Collaborative Learning. All of them are informed by Foucault, Pecheux, Bakhtin, Gardner, Levy, and others. The theoretical contribution is justified to the extent that the student is above all a being inserted into a user company tool created by it over time, to act on the world. Theoretical principles underlying the construction of learning objects as tools for teaching are related to teaching and learning. The developed learning object establishes the link between the fields of pedagogy and usability, the step by step construction of each of them and their purposes, characteristics, and all detailed in the development of research. The construction of the learning object follows the steps of a methodological construction for the development of a computerized product, followed by a systematic planning and the design and construction.
文摘In this paper, used BSO(Bi12SiO(20)) crystal as a hologram recording material,TV-camera as a detector, and a holographic setup controlled by a computer, automatically calculating hologram of 3-interferograms method is theoretically and experimentally studied. This new holographic recording material and automatically calculating hologram make it possible to use real-time holography in an industry. As a practical example, the shrinking of 2-components adhesive in 4 h is measured.