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From rectangle to parallelogram:an area-weighted method to make time-space diagrams incorporate traffic waves
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作者 Ning Wang Xingye Wang +1 位作者 Hai Yan Zhengbing He 《Digital Transportation and Safety》 2024年第1期1-7,共7页
A time-space(TS)traffic diagram is one of the most important tools for traffic visualization and analysis.Recently,it has been empirically shown that using parallelogram cells to construct a TS diagram outperforms usi... A time-space(TS)traffic diagram is one of the most important tools for traffic visualization and analysis.Recently,it has been empirically shown that using parallelogram cells to construct a TS diagram outperforms using rectangular cells due to its incorporation of traffic wave speed.However,it is not realistic to immediately change the fundamental method of TS diagram construction that has been well embedded in various systems.To quickly make the existing TS diagram incorporate traffic wave speed and exhibit more realistic traffic patterns,the paper proposes an area-weighted transformation method that directly transforms rectangular-cell-based TS(rTS)diagrams into parallelogram-cell-based TS(pTS)diagrams,avoiding tracing back the raw data of speed to make the transformation.Two five-hour trajectory datasets from Japanese highway segments are used to demonstrate the effectiveness of the proposed methods.The travel time-based comparison involves assessing the disparities between actual travel times and those computed using rTS diagrams,as well as travel times derived directly from pTS diagrams based on rTS diagrams.The results show that travel times calculated from pTS diagrams converted from rTS diagrams are closer to the actual values,especially in congested conditions,demonstrating superior performance in parallelogram representation.The proposed transformation method has promising prospects for practical applications,making the widely-existing TS diagrams show more realistic traffic patterns. 展开更多
关键词 Spatiotemporal speed contour diagram Vehicle trajectory Traffic wave Traffic state
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A time-space network-based model for transportation service optimization of China Railway Express
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作者 Weichuan Yin Wenhu Hu +2 位作者 Xueting Yan Bo Peng Xiaoling Yang 《High-Speed Railway》 2024年第3期153-163,共11页
This paper describes the development and optimization plans for the China Railway Express(CR Express).As a new type of international land transport organization,CR Express has emerged with the continuous expansion of ... This paper describes the development and optimization plans for the China Railway Express(CR Express).As a new type of international land transport organization,CR Express has emerged with the continuous expansion of China toward European investment and trade,and in particular,has expanded with the continuous progress of the One Belt and One Road(OBOR)initiative.In addition to improving the service quality of CR Express,the operating costs must be reduced for developing“smart railways”that serve“smart cities”.We propose a dualobjective-based function mathematical optimization model;the satisfaction of the cargo owner is considered,and the timeliness,transportation capacity,and goods category constraints of CR Express transportation are designed.Moreover,we present the normalized equivalent method of the two-objective function of the model.Finally,a case study is conducted against the background of certain trains in the western corridor of CR Express to validate the effectiveness of the model and research methods proposed in this study. 展开更多
关键词 One Belt and One Road China Railway Express Transportation service Mathematical optimization time-space network
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Finite Difference Schemes for Time-Space Fractional Diffusion Equations in One-and Two-Dimensions
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作者 Yu Wang Min Cai 《Communications on Applied Mathematics and Computation》 EI 2023年第4期1674-1696,共23页
In this paper,finite difference schemes for solving time-space fractional diffusion equations in one dimension and two dimensions are proposed.The temporal derivative is in the Caputo-Hadamard sense for both cases.The... In this paper,finite difference schemes for solving time-space fractional diffusion equations in one dimension and two dimensions are proposed.The temporal derivative is in the Caputo-Hadamard sense for both cases.The spatial derivative for the one-dimensional equation is of Riesz definition and the two-dimensional spatial derivative is given by the fractional Laplacian.The schemes are proved to be unconditionally stable and convergent.The numerical results are in line with the theoretical analysis. 展开更多
关键词 time-space fractional diffusion equation Caputo-Hadamard derivative Riesz derivative Fractional Laplacian Numerical analysis
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Properties of the phase diagram from the Nambu-Jona-Lasino model with a scalar-vector interaction
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作者 Yong-Hang Yang He Liu Peng-Cheng Chu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第10期168-179,共12页
We investigated the properties of the phase diagram of high-order susceptibilities,speed of sound,and polytropic index based on an extended Nambu-Jona-Lasinio model with an eight-quark scalar-vector interaction.Non-mo... We investigated the properties of the phase diagram of high-order susceptibilities,speed of sound,and polytropic index based on an extended Nambu-Jona-Lasinio model with an eight-quark scalar-vector interaction.Non-monotonic behavior was observed in all these quantities around the phase transition boundary,which also revealed the properties of the critical point.Further,this study indicated that the chiral phase transition boundary and critical point could vary depending on the scalarvector coupling constant G_(SV).At finite densities and temperatures,the negative G_(SV)term exhibited attractive interactions,which enhanced the critical point temperature and reduced the chemical potential.The G_(SV)term also affected the properties of the high-order susceptibilities,speed of sound,and polytropic index near the critical point.The non-monotonic(peak or dip)structures of these quantities shifted to a low baryon chemical potential(and high temperature)with a negative G_(SV).G_(SV)also changed the amplitude and range of the nonmonotonic regions.Therefore,the scalar-vector interaction was useful for locating the phase boundary and critical point in QCD phase diagram by comparing the experimental data.The study of the non-monotonic behavior of high-order susceptibilities,speed of sound,and polytropic index is of great interest,and further observations related to high-order susceptibilities,speed of sound,and polytropic index being found and applied to the search for critical points in heavy-ion collisions and the study of compact stars are eagerly awaited. 展开更多
关键词 QCD phase diagram High-order susceptibilities Speed of sound Polytropic index NJL model
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Curved Spine:The Shape of Spine in Taoist Body Diagrams and Its Influence on Medical Body Diagrams
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作者 ZHANG Xinyue ZHANG Shujian 《Chinese Medicine and Culture》 2024年第3期251-261,共11页
From the early Taoist diagrams of the human body to the end of the Qing dynasty and the beginning of the Republic of China,Taoists exaggerated and deformed the human spine in a shape-shifting manner.It is likely that ... From the early Taoist diagrams of the human body to the end of the Qing dynasty and the beginning of the Republic of China,Taoists exaggerated and deformed the human spine in a shape-shifting manner.It is likely that medical practitioners were influenced by this style of representation,and there are also numerous diagrams of the human body with the curved spine in the lateral-view diagrams of viscera and Ming Tang Tu(明堂图Acupuncture and Moxibustion Chart),which constantly show the human torso in an elliptical“egg shape”.No later than the Ming dynasty,medical practitioners began to depict the actual physiological spinal curve of the human body.By the Qing dynasty,the depiction of the spinal curve in medical diagrams of the human figure showed a tendency to part ways with the Taoist freehand style of the previous generation.Although the representation of the curve of the spine was very crude,later medical images of the human body at least gradually straightened the spine and no longer depicted it in a shape-shifting manner.However,the curved spine in Taoist diagrams of the human body continued to exist,and the presentation of the curved spine never changed.This way of depicting its appearance,which is very different from reality,is shaped by Taoism's special way of perceiving and viewing the body,and may also contain another form of truth. 展开更多
关键词 SPINE diagrams of human body Taoists Traditional Chinese medical practitioners
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Recension of boron nitride phase diagram based on high-pressure and high-temperature experiments
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作者 Ruike Zhang Ruiang Guo +3 位作者 Qian Li Shuaiqi Li Haidong Long Duanwei He 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期450-457,共8页
Cubic boron nitride and hexagonal boron nitride are the two predominant crystalline structures of boron nitride.They can interconvert under varying pressure and temperature conditions.However,this transformation requi... Cubic boron nitride and hexagonal boron nitride are the two predominant crystalline structures of boron nitride.They can interconvert under varying pressure and temperature conditions.However,this transformation requires overcoming significant potential barriers in dynamics,which poses great difficulty in determining the c-BN/h-BN phase boundary.This study used high-pressure in situ differential thermal measurements to ascertain the temperature of h-BN/c-BN conversion within the commonly used pressure range(3-6 GPa)for the industrial synthesis of c-BN to constrain the P-T phase boundary of h-BN/c-BN in the pressure-temperature range as much as possible.Based on the analysis of the experimental data,it is determined that the relationship between pressure and temperature conforms to the following equation:P=a+1/bT.Here,P denotes the pressure(GPa)and T is the temperature(K).The coefficients are a=-3.8±0.8 GPa and b=229.8±17.1 GPa/K.These findings call into question existing high-pressure and high-temperature phase diagrams of boron nitride,which seem to overstate the phase boundary temperature between c-BN and h-BN.The BN phase diagram obtained from this study can provide critical temperature and pressure condition guidance for the industrial synthesis of c-BN,thus optimizing synthesis efficiency and product performance. 展开更多
关键词 hexagonal boron nitride phase diagram high temperature and high pressure cubic boron nitride phase transition differential thermal analysis
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A Future Life of Binary Phase Diagrams
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作者 Yuri Ustinovshikov 《Advances in Materials Physics and Chemistry》 CAS 2024年第8期123-136,共14页
The article raises the question of what to do with one of the main achievements of metal science in recent years—binary phase diagrams. These diagrams play a key role in the science of alloys and therefore their reli... The article raises the question of what to do with one of the main achievements of metal science in recent years—binary phase diagrams. These diagrams play a key role in the science of alloys and therefore their reliability must be complete. However, the discovery of the “ordering-separation” phase transition, which showed that in binary alloys at certain temperatures the sign of the chemical interatomic interaction changes (and, consequently, the microstructure changes), forces us to reconsider our ideas about those areas. Currently, these areas are designated on diagrams as areas of a “disordered solid solution.” This article proposes, using transmission electron microscopy, to study all the so-called solid solution regions, and apply the results obtained to the studied regions of the phase diagram. 展开更多
关键词 Phase Transformation “Ordering-Separation” Electronic Transition “Ionic Bond Covalent Bond” Binary Phase diagrams Transmission Electron Microscopy
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TIME-SPACE CONCEPT FOR PRECISION MEASUREMENT 被引量:4
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作者 LIU Xiaokang PENG Donglin ZHU Ge WANG Xianquan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第3期112-115,共4页
The transformation between time and space is discussed. To improve real-time response speed of intelligent measuring system, the concept of exchanging program execution time with more circuitry is presented working in... The transformation between time and space is discussed. To improve real-time response speed of intelligent measuring system, the concept of exchanging program execution time with more circuitry is presented working in cycle mode. Displacement measuring by magnification is achieved with period measurement by magnification. To change the condition that traditional precision measurement depends on machining precision greatly, the concept of measuring space with time and theory of time-space coordinate transformation are proposed. Guided by the idea of measuring space with time, differential frequency measurement system and time grating displacement sensor are developed based on the proposed novel methods. And high-precision measurement is achieved without high-precision manufacture, which embeds the remarkable characteristics of low cost but high precision to the devices. Experiment and test results conform the validity of the proposed time-space concept. 展开更多
关键词 time-space Precision measurement Control flow Differential frequency Time grating
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Adaptive time-space resource and waveform control for collocated MIMO radar with simultaneous multi-beam 被引量:4
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作者 CHENG Ting LI Xi +1 位作者 TAN Qianqian SU Yang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第1期47-59,共13页
Collocated multiple input multiple output(MIMO)radar,which has agile multi-beam working mode,can offer enhanced multiple targets tracking(MTT)ability.In detail,it can illuminate different targets simultaneously with m... Collocated multiple input multiple output(MIMO)radar,which has agile multi-beam working mode,can offer enhanced multiple targets tracking(MTT)ability.In detail,it can illuminate different targets simultaneously with multi-beam or one wide beam among multi-beam,providing greater degree of freedom in system resource control.An adaptive time-space resource and waveform control optimization model for the collocated MIMO radar with simultaneous multi-beam is proposed in this paper.The aim of the proposed scheme is to improve the overall tracking accuracy and meanwhile minimize the resource consumption under the guarantee of effective targets detection.A resource and waveform control algorithm which integrates the genetic algorithm(GA)is proposed to solve the optimization problem.The optimal transmitting waveform parameters,system sampling period,sub-array number,binary radar tracking parameterχ_i(t_k),transmitting energy and multi-beam direction vector combination are chosen adaptively,where the first one realizes the waveform control and the latter five realize the timespace resource allocation.Simulation results demonstrate the effectiveness of the proposed control method. 展开更多
关键词 multiple targets tracking(MTT) collocated multiple input multiple output(MIMO)radar time-space resource allocation waveform control
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Adaptive resource management for multi-target tracking in co-located MIMO radar based on time-space joint allocation 被引量:1
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作者 SU Yang CHENG Ting +2 位作者 HE Zishu LI Xi LU Yanxi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第5期916-927,共12页
Compared with the traditional phased array radar, the co-located multiple-input multiple-output(MIMO) radar is able to transmit orthogonal waveforms to form different illuminating modes, providing a larger freedom deg... Compared with the traditional phased array radar, the co-located multiple-input multiple-output(MIMO) radar is able to transmit orthogonal waveforms to form different illuminating modes, providing a larger freedom degree in radar resource management. In order to implement the effective resource management for the co-located MIMO radar in multi-target tracking,this paper proposes a resource management optimization model,where the system resource consumption and the tracking accuracy requirements are considered comprehensively. An adaptive resource management algorithm for the co-located MIMO radar is obtained based on the proposed model, where the sub-array number, sampling period, transmitting energy, beam direction and working mode are adaptively controlled to realize the time-space resource joint allocation. Simulation results demonstrate the superiority of the proposed algorithm. Furthermore, the co-located MIMO radar using the proposed algorithm can satisfy the predetermined tracking accuracy requirements with less comprehensive cost compared with the phased array radar. 展开更多
关键词 co-located multiple-input multiple-output(MIMO)radar adaptive resource management multi-target tracking sub-array division time-space joint allocation
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A Time-Space Optimal Parallel Sorting on a Hypercube
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作者 QI JIANXIAN (Beijing Institute of System Engineering P. O.Box 9702-19, Beijing, People ’s Repuslic of China) 《Wuhan University Journal of Natural Sciences》 CAS 1996年第Z1期465-469,共5页
In this paper we discuss a parallel sorting algorithm on a hypercube. Its time complexity is O(n logn/p) +O(n). Here, P is the number of processors available and n, the amount of items to be sorted. Take the problem o... In this paper we discuss a parallel sorting algorithm on a hypercube. Its time complexity is O(n logn/p) +O(n). Here, P is the number of processors available and n, the amount of items to be sorted. Take the problem of time-space optimization into consideration, when P≤ O(log n), this algorithm is both timespace optimal and cost optimization. But this means only speedup is O(P) and it is not linear speedup. Therefore, we further discuss relevant parallel efficiency problems. 展开更多
关键词 HYPERCUBE Parallel Sorting time-space Optimal EFFICIENCY COST Operations.
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A "TIME-SPACE" RELATED DESIGN METHOD OF FREEZING WALL
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作者 陈湘生 《Journal of Coal Science & Engineering(China)》 1996年第2期63-66,共4页
Artificially ground freezing (AGF) is one of the main methods to establish temporary support for shaft sinking in unstable water bearing strata. Domde (1915) formula based on frozen soil strength has widely been used ... Artificially ground freezing (AGF) is one of the main methods to establish temporary support for shaft sinking in unstable water bearing strata. Domde (1915) formula based on frozen soil strength has widely been used for designing freezing wall thickness. However, it can not ensure the stability of freezing wall, nor guarantee the safety of shaft construction as frozen depth increases in unstable water bearing strata. F A. Auld (1985, 1988)[1,2] presented a design method of freezing wall, which is on the basis of strength and stability, together with deformation of freezing wall. This paper, according to the practice in China, describes a "time -space" related design method for deep freezing wall. The method is based on "time-space" concept, which includes influence of excavation rate of advance, unsupported length of freezing wall and the sump state on inward deformation of freezing wall, and the allowable pipe deformation caused by inward deformation of freezing wall. Finally, successful application of this method to the large scale coal mine-Jining No. 2 Mine[3] in Shandong Province of China is presented. It saved much investment compared with F. A. Auld’s design for the same mine. 展开更多
关键词 ground freezing freezing wall DESIGN time-space concept
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A traffic model of optical networks based on time-space complexity and traffic grooming
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作者 赵永利 《High Technology Letters》 EI CAS 2009年第2期198-202,共5页
This paper researched the traffic of optical networks in time-space complexity,proposed a novel traf-fic model for complex optical networks based on traffic grooming,designed a traffic generator GTS(gener-ator based o... This paper researched the traffic of optical networks in time-space complexity,proposed a novel traf-fic model for complex optical networks based on traffic grooming,designed a traffic generator GTS(gener-ator based on time and space)with 'centralized+distributed' idea,and then made a simulation in Clanguage.Experiments results show that GTS can produce the virtual network topology which can changedynamically with the characteristic of scaling-free network.GTS can also groom the different traffic andtrigger them under real-time or scheduling mechanisms,generating different optical connections.Thistraffic model is convenient for the simulation of optical networks considering the traffic complexity. 展开更多
关键词 optical networks traffic model time-space complexity scaling-free SELF-SIMILARITY traffic grooming
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Petrochemical eigenvalues and diagrams for the identification of metamorphic rocks'protolith,taking the host rocks of Dashuigou tellurium deposit in China as an example 被引量:1
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作者 Jianzhao Yin Shoupu Xiang +2 位作者 Yuhong Chao Yuhan Yin Hongyun Shi 《Acta Geochimica》 EI CAS CSCD 2023年第1期103-124,共22页
The Dashuigou tellurium deposit is the world’s only known independent tellurium deposit.By restoring metamorphic rocks’protolith,we seek to understand not only the development and evolution trajectory of the region ... The Dashuigou tellurium deposit is the world’s only known independent tellurium deposit.By restoring metamorphic rocks’protolith,we seek to understand not only the development and evolution trajectory of the region but also the origin of the relevant deposits.While there are many ways to restore metamorphic rocks’protolith,we take the host metamorphic rocks of Dashuigou tellurium deposit and leverage various petrochemical eigenvalues and related diagrams previously proposed to reveal the deposit’s host metamorphic rocks’protolith.The petrochemical eigenvalues include molecular number,Niggli’s value,REE parity ratio,CaO/Al_(2)O_(3)ratio,Fe^(3+) /(Fe^(3+) -+Fe^(2+) )ratio,chondrite-normalized REE value,logarithmic REE value,various REE eigenvalues including scandium,Eu/Sm ratio,total REE amount,light and heavy REEs,δEu,Eu anomaly,Sm/Nd ratio,and silicon isotope δ^(30) SiNBS-29‰,etc.The petrochemical plots include ACMs,100 mg-c-(al+alk),SiO_(2)-(Na_(2)O+K_(2)O),(al+fm)-(c+alk)versus Si,FeO+Fe_(2)O^(3+) TiO)-Al_(2)O_(3)-MgO,c-mg,Al_(2)O_(3)-(Na_(2)O+K_(2)O),chondrite-normalized REE model,La/Yb-REE,and Sm/Nd ratio,etc.On the basis of these comprehensive analyses,the following conclusions are drawn,starting from the many mantle-derived types of basalt developed in the study area of different geological ages,combined with the previously published research results on the deposit s fluid inclusions and sulfur and lead isotopes.The deposit is formed by mantle degassing in the form of a mantle plume in the late Yanshanian orogeny.The degassed fluids are rich in nano-sc ale substances including Fe,Te,S,As,Bi,Au,Se,H_(2),CO_(2),N_(2),H_(2)O,and CH_(4),which are enriched by nano-effect,and then rise to a certain part of the crust in the form of mantle plume along the lithospheric fault to form the deposit.The ultimate power for tellurium mineralization was from H_(2)flow with high energy,which was produced through radiation from the melted iron of the Earth’s outer core.The H,flow results in the Earth’s degassing,as well as the mantle and crust’s uplift. 展开更多
关键词 Petrochemical diagrams and eigenvalue PROTOLITH Metamorphic rock Independent tellurium deposit Host rock The mantle plume
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A reasoning diagram based method for fault diagnosis of railway point system 被引量:1
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作者 Feng Wang Yuan Cao +4 位作者 Clive Roberts Tao Wen Lei Tan Shuai Su Tao Tang 《High-Speed Railway》 2023年第2期110-119,共10页
Railway Point System(RPS)is an important infrastructure in railway industry and its faults may have significant impacts on the safety and efficiency of train operations.For the fault diagnosis of RPS,most existing met... Railway Point System(RPS)is an important infrastructure in railway industry and its faults may have significant impacts on the safety and efficiency of train operations.For the fault diagnosis of RPS,most existing methods assume that sufficient samples of each failure mode are available,which may be unrealistic,especially for those modes of low occurrence frequency but with high risk.To address this issue,this work proposes a novel fault diagnosis method that only requires the power signals generated under normal RPS operations in the training stage.Specifically,the failure modes of RPS are distinguished through constructing a reasoning diagram,whose nodes are either binary logic problems or those that can be decomposed into the problems of the binary logic.Then,an unsupervised method for the signal segmentation and a fault detection method are combined to make decisions for each binary logic problem.Based on the results of decisions,the diagnostic rules are established to identify the failure modes.Finally,the data collected from multiple real-world RPSs are used for validation and the results demonstrate that the proposed method outperforms the benchmark in identifying the faults of RPSs. 展开更多
关键词 Railway point system Fault diagnosis Reasoning diagram SEGMENTATION Detection method
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Modeling of Surface Waves in a Fluid Saturated Poro-Elastic Medium under Initial Stress Using Time-Space Domain Higher Order Finite Difference Method
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作者 Anjana P. Ghorai R. Tiwary 《Applied Mathematics》 2013年第3期469-476,共8页
In this present context, mathematical modeling of the propagation of surface waves in a fluid saturated poro-elastic medium under the influence of initial stress has been considered using time dependent higher order f... In this present context, mathematical modeling of the propagation of surface waves in a fluid saturated poro-elastic medium under the influence of initial stress has been considered using time dependent higher order finite difference method (FDM). We have proved that the accuracy of this finite-difference scheme is 2M when we use 2nd order time domain finite-difference and 2M-th order space domain finite-difference. It also has been shown that the dispersion curves of Love waves are less dispersed for higher order FDM than of lower order FDM. The effect of initial stress, porosity and anisotropy of the layer in the propagation of Love waves has been studied here. The numerical results have been shown graphically. As a particular case, the phase velocity in a non porous elastic solid layer derived in this paper is in perfect agreement with that of Liu et al. (2009). 展开更多
关键词 LOVE WAVES FLUID Saturated Initially Stressed POROUS Layer time-space Domain Finite DIFFERENCE Scheme Accuracy Dispersion Analysis Phase Velocity
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Earthquake-Affected Time-Space Domain, Recurrence Interval and Effective Preparation Time of Earthquakes
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作者 Wang Shengzu and Zhang ZongchunInstitute of Geology & Laboratory of Tectonophysics, China Seismological Bureau, Beijing 100029, China 《Earthquake Research in China》 2002年第4期380-395,共16页
The study shows that earthquake-affected time-space domain (ETSD), i.e. a time-space range in which strong earthquakes are unable to occur owing to the influence of a prior earthquake occurring, shows a hyperbolic mar... The study shows that earthquake-affected time-space domain (ETSD), i.e. a time-space range in which strong earthquakes are unable to occur owing to the influence of a prior earthquake occurring, shows a hyperbolic margin curve in the t(time)-r(distance) coordinate plane, which has a maximum affected radius r 0 at t=0 and a maximum influence time t 0 (i.e. the in-situ recurrence interval of earthquakes) at r=0. Based on the time-distance distributions of posterior earthquakes relative to prior ones in the regions of North China, Northwest China, Qinghai-Xizang (Tibet) plateau and Southwest China, the optimized and 90%-confidence margin curves are estimated using optimization and statistical analysis methods. This indicates that the concept and method of ETSD with 3-dimension (time-distance-magnitudes) instead of those of “recurrence interval" with 1-dimension (time) or 2-dimension (time-magnitude) provides a new approach to understanding the fluctuation of seismic activities, estimating the effective earthquake-preparation time of potential hypocenters, and therefore improving the medium- and long-term prediction of strong earthquakes. 展开更多
关键词 Earthquake-affected time-space domain Recurrence interval Affected radius Effective earthquake-preparation time
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SLC Method and Earthquakes' Clustering Features in Time-Space in the Top Area of the Kunlun-Altun-Arc
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作者 Zhou Huilan,Liu Zhen,and Gao YuanGraduate School,University of Sciences and Technology of China,Beijing 100039,China 《Earthquake Research in China》 1998年第1期3-12,共10页
By using the SLC(Single-Link Cluster)method,this study worked in three respects:(a)set up three-dimensional(3-D)SLC software that can deal with a large catalogue of earthquakes and analyze the characteristics of earth... By using the SLC(Single-Link Cluster)method,this study worked in three respects:(a)set up three-dimensional(3-D)SLC software that can deal with a large catalogue of earthquakes and analyze the characteristics of earthquakes’ clustering and scattering in time-space:(b)defined several parameters to describe the distinguishing feature for the SLC frame and developed a technique to calculate the 3-D SLC frames and these parameters with gradual time-sliding,and inspected their variations with time,especially before large events; and(c)by using these means,treated the earthquake catalogue in the top area of the Kunlun-Altun-Arc as well as some valuable results that had been obtained. 展开更多
关键词 SLC clustering in time-space characteristic link length SEISMICITY Kunlun-Altun Mountains.
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Solving Algebraic Problems with Geometry Diagrams Using Syntax-Semantics Diagram Understanding
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作者 Litian Huang Xinguo Yu +1 位作者 Lei Niu Zihan Feng 《Computers, Materials & Continua》 SCIE EI 2023年第10期517-539,共23页
Solving Algebraic Problems with Geometry Diagrams(APGDs)poses a significant challenge in artificial intelligence due to the complex and diverse geometric relations among geometric objects.Problems typically involve bo... Solving Algebraic Problems with Geometry Diagrams(APGDs)poses a significant challenge in artificial intelligence due to the complex and diverse geometric relations among geometric objects.Problems typically involve both textual descriptions and geometry diagrams,requiring a joint understanding of these modalities.Although considerable progress has been made in solving math word problems,research on solving APGDs still cannot discover implicit geometry knowledge for solving APGDs,which limits their ability to effectively solve problems.In this study,a systematic and modular three-phase scheme is proposed to design an algorithm for solving APGDs that involve textual and diagrammatic information.The three-phase scheme begins with the application of the statetransformer paradigm,modeling the problem-solving process and effectively representing the intermediate states and transformations during the process.Next,a generalized APGD-solving approach is introduced to effectively extract geometric knowledge from the problem’s textual descriptions and diagrams.Finally,a specific algorithm is designed focusing on diagram understanding,which utilizes the vectorized syntax-semantics model to extract basic geometric relations from the diagram.A method for generating derived relations,which are essential for solving APGDs,is also introduced.Experiments on real-world datasets,including geometry calculation problems and shaded area problems,demonstrate that the proposed diagram understanding method significantly improves problem-solving accuracy compared to methods relying solely on simple diagram parsing. 展开更多
关键词 Algebraic problems with geometry diagrams problem-solving geometry diagram understanding state-transformer paradigm syntax-semantics model
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Prediction and Verifcation of Forming Limit Diagrams Based on a Modifed Shear Failure Criterion
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作者 Haibo Wang Zipeng Wang +1 位作者 Yu Yan Yuanhui Xu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第5期364-373,共10页
The forming limit diagram plays an important role in predicting the forming limit of sheet metals.Previous studies have shown that,the method to construct the forming limit diagram based on instability theory of the o... The forming limit diagram plays an important role in predicting the forming limit of sheet metals.Previous studies have shown that,the method to construct the forming limit diagram based on instability theory of the original shear failure criterion is efective and simple.The original shear instability criterion can accurately predict the left area of the forming limit diagram but not the right area.In this study,in order to improve the accuracy of the original shear failure criterion,a modifed shear failure criterion was proposed based on in-depth analysis of the original shear failure criterion.The detailed improvement strategies of the shear failure criterion and the complete calculation process are given.Based on the modifed shear failure criterion and diferent constitutive equations,the theoretical forming limit of TRIP780 steel and 5754O aluminum alloy sheet metals are calculated.By comparing the theoretical and experimental results,it is shown that proposed modifed shear failure criterion can predict the right area of forming limit more reasonably than the original shear failure criterion.The efect of the pre-strain and constitutive equation on the forming limits are also analyzed in depth.The modifed shear failure criterion proposed in this study provides an alternative and reliable method to predict forming limit of sheet metals. 展开更多
关键词 Modifed shear failure criterion Sheet metal forming Forming limit diagram Loading path
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