期刊文献+
共找到14,154篇文章
< 1 2 250 >
每页显示 20 50 100
Curved Space-Time at the Planck Scale
1
作者 Lewis Nash 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期167-179,共13页
This paper presents a physically plausible and somewhat illuminating first step in extending the fundamental principles of mechanical stress and strain to space-time. Here the geometry of space-time, encoded in the me... This paper presents a physically plausible and somewhat illuminating first step in extending the fundamental principles of mechanical stress and strain to space-time. Here the geometry of space-time, encoded in the metric tensor, is considered to be made up of a dynamic lattice of extremely small, localized fields that form a perfectly elastic Lorentz symmetric space-time at the global (macroscopic) scale. This theoretical model of space-time at the Planck scale leads to a somewhat surprising result in which matter waves in curved space-time radiate thermal gravitational energy, as well as an equally intriguing relationship for the anomalous dispersion of light in a gravitational field. 展开更多
关键词 Schwarzschild space-time Continuum Mechanics Planck Lattice Gravitational Radiation
下载PDF
Multi-scale Incremental Analysis Update Scheme and Its Application to Typhoon Mangkhut(2018)Prediction
2
作者 Yan GAO Jiali FENG +4 位作者 Xin XIA Jian SUN Yulong MA Dongmei CHEN Qilin WAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第1期95-109,共15页
In the traditional incremental analysis update(IAU)process,all analysis increments are treated as constant forcing in a model’s prognostic equations over a certain time window.This approach effectively reduces high-f... In the traditional incremental analysis update(IAU)process,all analysis increments are treated as constant forcing in a model’s prognostic equations over a certain time window.This approach effectively reduces high-frequency oscillations introduced by data assimilation.However,as different scales of increments have unique evolutionary speeds and life histories in a numerical model,the traditional IAU scheme cannot fully meet the requirements of short-term forecasting for the damping of high-frequency noise and may even cause systematic drifts.Therefore,a multi-scale IAU scheme is proposed in this paper.Analysis increments were divided into different scale parts using a spatial filtering technique.For each scale increment,the optimal relaxation time in the IAU scheme was determined by the skill of the forecasting results.Finally,different scales of analysis increments were added to the model integration during their optimal relaxation time.The multi-scale IAU scheme can effectively reduce the noise and further improve the balance between large-scale and small-scale increments in the model initialization stage.To evaluate its performance,several numerical experiments were conducted to simulate the path and intensity of Typhoon Mangkhut(2018)and showed that:(1)the multi-scale IAU scheme had an obvious effect on noise control at the initial stage of data assimilation;(2)the optimal relaxation time for large-scale and small-scale increments was estimated as 6 h and 3 h,respectively;(3)the forecast performance of the multi-scale IAU scheme in the prediction of Typhoon Mangkhut(2018)was better than that of the traditional IAU scheme.The results demonstrate the superiority of the multi-scale IAU scheme. 展开更多
关键词 multi-scale incremental analysis updates optimal relaxation time 2-D discrete cosine transform GRAPES_MESO Typhoon Mangkhut(2018)
下载PDF
Performance Analysis for Orthogonal Time Frequency Space Modulation Systems with Generalized Waveform
3
作者 Shuo Li Lixia Xiao +3 位作者 Yangyang Liu Guanghua Liu Pei Xiao Tao Jiang 《China Communications》 SCIE CSCD 2023年第4期57-72,共16页
Orthogonal time-frequency space(OTFS),which exhibits beneficial advantages in high-mobility scenarios,has been considered as a promising technology in future wireless communication systems.In this paper,a universal mo... Orthogonal time-frequency space(OTFS),which exhibits beneficial advantages in high-mobility scenarios,has been considered as a promising technology in future wireless communication systems.In this paper,a universal model for OTFS systems with generalized waveform has been developed.Furthermore,the average bit error probability(ABEP)upper bounds of the optimal maximum likelihood(ML)detector are first derived for OTFS systems with generalized waveforms.Specifically,for OTFS systems with the ideal waveform,we elicit the ABEP bound by recombining the transmitted signal and the received signal.For OTFS systems with practical waveforms,a universal ABEP upper bound expression is derived using moment-generating function(MGF),which is further extended to MIMO-OTFS systems.Numerical results validate that our theoretical ABEP upper bounds are concur with the simulation performance achieved by ML detectors. 展开更多
关键词 orthogonal time frequency space(OTFS) average bite error rate(ABEP) maximum likelihood(ML) moment generating-function(MGF)
下载PDF
Heterogeneous information phase space reconstruction and stability prediction of filling body–surrounding rock combination
4
作者 Dapeng Chen Shenghua Yin +5 位作者 Weiguo Long Rongfu Yan Yufei Zhang Zepeng Yan Leiming Wang Wei Chen 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第7期1500-1511,共12页
Traditional research believes that the filling body can effectively control stress concentration while ignoring the problems of unknown stability and the complex and changeable stress distribution of the filling body... Traditional research believes that the filling body can effectively control stress concentration while ignoring the problems of unknown stability and the complex and changeable stress distribution of the filling body–surrounding rock combination under high-stress conditions.Current monitoring data processing methods cannot fully consider the complexity of monitoring objects,the diversity of monitoring methods,and the dynamics of monitoring data.To solve this problem,this paper proposes a phase space reconstruction and stability prediction method to process heterogeneous information of backfill–surrounding rock combinations.The three-dimensional monitoring system of a large-area filling body–surrounding rock combination in Longshou Mine was constructed by using drilling stress,multipoint displacement meter,and inclinometer.Varied information,such as the stress and displacement of the filling body–surrounding rock combination,was continuously obtained.Combined with the average mutual information method and the false nearest neighbor point method,the phase space of the heterogeneous information of the filling body–surrounding rock combination was then constructed.In this paper,the distance between the phase point and its nearest point was used as the index evaluation distance to evaluate the stability of the filling body–surrounding rock combination.The evaluated distances(ED)revealed a high sensitivity to the stability of the filling body–surrounding rock combination.The new method was then applied to calculate the time series of historically ED for 12 measuring points located at Longshou Mine.The moments of mutation in these time series were at least 3 months ahead of the roadway return dates.In the ED prediction experiments,the autoregressive integrated moving average model showed a higher prediction accuracy than the deep learning models(long short-term memory and Transformer).Furthermore,the root-mean-square error distribution of the prediction results peaked at 0.26,thus outperforming the no-prediction method in 70%of the cases. 展开更多
关键词 deep mining filling body–surrounding rock combination phase space reconstruction multiple time series stability prediction
下载PDF
Motion and Special Relativity in Complex Spaces
5
作者 Jerzy K. Filus 《Journal of Applied Mathematics and Physics》 2024年第1期330-361,共32页
A natural extension of the Lorentz transformation to its complex version was constructed together with a parallel extension of the Minkowski M<sup>4</sup> model for special relativity (SR) to complex C<... A natural extension of the Lorentz transformation to its complex version was constructed together with a parallel extension of the Minkowski M<sup>4</sup> model for special relativity (SR) to complex C<sup>4</sup> space-time. As the [signed] absolute values of complex coordinates of the underlying motion’s characterization in C<sup>4</sup> one obtains a Newtonian-like type of motion whereas as the real parts of the complex motion’s description and of the complex Lorentz transformation, all the SR theory as modeled by M<sup>4</sup> real space-time can be recovered. This means all the SR theory is preserved in the real subspace M<sup>4</sup> of the space-time C<sup>4</sup> while becoming simpler and clearer in the new complex model’s framework. Since velocities in the complex model can be determined geometrically, with no primary use of time, time turns out to be definable within the equivalent theory of the reduced complex C<sup>4</sup> model to the C<sup>3</sup> “para-space” model. That procedure allows us to separate time from the (para)space and consider all the SR theory as a theory of C<sup>3</sup> alone. On the other hand, the complex time defined within the C<sup>3</sup> theory is interpreted and modeled by the single separate C<sup>1</sup> complex plane. The possibility for application of the C<sup>3</sup> model to quantum mechanics is suggested. As such, the model C<sup>3</sup> seems to have unifying abilities for application to different physical theories. 展开更多
关键词 Special Relativity Complex space and time Models and Dramatic SR Simplification Complex time and space Separation Complex time Interpretation
下载PDF
Physical Space Is Finite
6
作者 Youqi Wang 《Journal of Modern Physics》 2024年第5期550-595,共46页
Metrological analysis shows that any clock in inertial motion in infinite space shall not have time dilation, due to relativity of such motion in such space. On the other hand, atomic clock in inertial motion in finit... Metrological analysis shows that any clock in inertial motion in infinite space shall not have time dilation, due to relativity of such motion in such space. On the other hand, atomic clock in inertial motion in finite space shall exhibit time dilation, due to alteration of momentum of clock-defining particle caused by nonzero curvature of trajectory of such motion in such space. Therefore, time dilation experiment of atomic clock in inertial motion in physical space provides a direct and decisive way of determining geometry of physical space in real-time. Phenomenon of time dilation of atomic clock in inertial motion in physical space has long been observed and confirmed experimentally. Therefore, extent of physical space has to be finite, consistent with result of high precision experiment of free particle in high-speed motion conducted a decade ago.Keywords Geometry of Physical Space, Time Dilation, Atomic Clock, Special Relativity Theory. 展开更多
关键词 Geometry of Physical space time Dilation Atomic Clock Special Relativity Theory
下载PDF
Coulomb Force, Charge, and Electric Properties under Collision Space-Time
7
作者 Espen Gaarder Haug 《Journal of Applied Mathematics and Physics》 2023年第3期686-704,共19页
We have recently published a series of papers on a theory we call collision space-time, that seems to unify gravity and quantum mechanics. In this theory, mass and energy are redefined. We have not so far demonstrated... We have recently published a series of papers on a theory we call collision space-time, that seems to unify gravity and quantum mechanics. In this theory, mass and energy are redefined. We have not so far demonstrated how to make it compatible with electric properties such as charge and the Coulomb force. The aim of this paper is to show how electric properties can be reformulated to make it consistent with collision space-time. It is shown that we need to incorporate the Planck scale into the electric constants to do so. This is also fully possible from a practical point of view, as it has recently been shown how to measure the Planck length independent of other constants and without the need for dimensional analysis. 展开更多
关键词 Coulomb’s Law Elementary Charge Planck Charge Electric Units Collision space-time
下载PDF
基于CiteSpace的侦查思维研究进展与趋势分析
8
作者 王春梅 成晓忆 孟小泸 《警学研究》 2024年第1期82-97,共16页
为掌握侦查思维研究进展并预测研究趋势,以中国知网(CNKI)学术期刊库2003—2023年收录的侦查思维相关期刊论文为数据基础,运用CiteSpace软件对侦查思维研究进行可视化分析。分析结果显示,侦查思维领域研究进展从时间上看可分为四个时期... 为掌握侦查思维研究进展并预测研究趋势,以中国知网(CNKI)学术期刊库2003—2023年收录的侦查思维相关期刊论文为数据基础,运用CiteSpace软件对侦查思维研究进行可视化分析。分析结果显示,侦查思维领域研究进展从时间上看可分为四个时期,即初步探索期、推陈出新期、逐步深入期和持续深入期;从空间上看,刘洪波、马前进侧重研究侦查逻辑思维方法与基本模式,巩寒冰侧重证据法学理论视角下的侦查思维模式,研究热点有传统侦查思维方法、侦查思维变革及侦查思维模式等。反思当前研究现状可见,侦查思维领域的高质量研究成果较少,且现有成果较为分散。因此,未来侦查思维研究应从拓深理论深度、丰富实证研究、整合研究成果形成并完善研究体系等方面进行。 展开更多
关键词 侦查思维 CITEspace 时空演进 趋势预测
下载PDF
Viscoacoustic prestack reverse time migration based onthe optimal time-space domain high-order finite-difference method 被引量:7
9
作者 赵岩 刘洋 任志明 《Applied Geophysics》 SCIE CSCD 2014年第1期50-62,116,共14页
Prestack reverse time migration (RTM) is an accurate imaging method ofsubsurface media. The viscoacoustic prestack RTM is of practical significance because itconsiders the viscosity of the subsurface media. One of t... Prestack reverse time migration (RTM) is an accurate imaging method ofsubsurface media. The viscoacoustic prestack RTM is of practical significance because itconsiders the viscosity of the subsurface media. One of the steps of RTM is solving thewave equation and extrapolating the wave field forward and backward; therefore, solvingaccurately and efficiently the wave equation affects the imaging results and the efficiencyof RTM. In this study, we use the optimal time-space domain dispersion high-order finite-difference (FD) method to solve the viscoacoustic wave equation. Dispersion analysis andnumerical simulations show that the optimal time-space domain FD method is more accurateand suppresses the numerical dispersion. We use hybrid absorbing boundary conditions tohandle the boundary reflection. We also use source-normalized cross-correlation imagingconditions for migration and apply Laplace filtering to remove the low-frequency noise.Numerical modeling suggests that the viscoacoustic wave equation RTM has higher imagingresolution than the acoustic wave equation RTM when the viscosity of the subsurface isconsidered. In addition, for the wave field extrapolation, we use the adaptive variable-lengthFD operator to calculate the spatial derivatives and improve the computational efficiencywithout compromising the accuracy of the numerical solution. 展开更多
关键词 REVERSE time migration Viscoacoustic Optimization Adaptive time-spacedomain FINITE-DIFFERENCE
下载PDF
基于space-time的二叉树表示动态环境中的路径规划
10
作者 唐平 何卓华 杨宜民 《计算机工程》 CAS CSCD 北大核心 2002年第5期59-60,74,共3页
研究具有空间和时间的三维动态环境下的机器人路径规划分析了四叉树表示二维空间的搜索算法,在此基础上,提出采space-time,用二叉树表示二维空间的方法时间信息中增加加速度利用二叉树遍历方法和算法设计一个在动态障碍物环境下进行路... 研究具有空间和时间的三维动态环境下的机器人路径规划分析了四叉树表示二维空间的搜索算法,在此基础上,提出采space-time,用二叉树表示二维空间的方法时间信息中增加加速度利用二叉树遍历方法和算法设计一个在动态障碍物环境下进行路径规划的新算法并,,A*,,在足球机器人系统中进行仿真,实现了较好的路径规划。 展开更多
关键词 移动机器人 数据结构 space-time 二叉树 动态环境 路径规划
下载PDF
Mechanical properties of multi-scale germanium specimens from space solar cells under electron irradiation
11
作者 Jian QIU Maliya HEINI +5 位作者 Jusha MA Wenjia HAN Xunchun WANG Jun YIN Yan SHI Cunfa GAO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第1期173-185,共13页
During long-term service in space,Gallium Arsenide(GaAs)solar cells are directly exposed to electron irradiation which usually causes a dramatic decrease in their performance.In the multilayer structure of solar cells... During long-term service in space,Gallium Arsenide(GaAs)solar cells are directly exposed to electron irradiation which usually causes a dramatic decrease in their performance.In the multilayer structure of solar cells,the germanium(Ge)layer occupies the majority of the thickness as the substrate.Due to the intrinsic brittleness of semiconductor material,there exist various defects during the preparation and assembly of solar cells,the influences of which tend to be intensified by the irradiation effect.In this work,first,Ge specimens for mechanical tests were prepared at scales from microscopic to macroscopic.Then,after different doses of electron irradiation,the mechanical properties of the Ge specimens were investigated.The experimental results demonstrate that electron irradiation has an obvious effect on the mechanical property variation of Ge in diverse scales.The four-point bending test indicates that the elastic modulus,fracture strength,and maximum displacement of the Ge specimens all increase,and reach the maximum value at the irradiation dose of 1×10^(15)e/cm^(2).The micrometer scale cantilever and nanoindentation tests present similar trends for Ge specimens after irradiation.Atomic Force Microscope(AFM)also observed the change in surface roughness.Finally,a fitting model was established to characterize the relation between modulus change and electron irradiation dose. 展开更多
关键词 Electron irradiation GERMANIUM Mechanical properties multi-scale space solar cells
原文传递
Formula for calculating spatial similarity degrees between point clouds on multi-scale maps taking map scale change as the only independent variable 被引量:5
12
作者 Yang Weifang Yan Haowen Li Jonathan 《Geodesy and Geodynamics》 2015年第2期113-125,共13页
The degree of spatial similarity plays an important role in map generalization, yet there has been no quantitative research into it. To fill this gap, this study first defines map scale change and spatial similarity d... The degree of spatial similarity plays an important role in map generalization, yet there has been no quantitative research into it. To fill this gap, this study first defines map scale change and spatial similarity degree/relation in multi-scale map spaces and then proposes a model for calculating the degree of spatial similarity between a point cloud at one scale and its gener- alized counterpart at another scale. After validation, the new model features 16 points with map scale change as the x coordinate and the degree of spatial similarity as the y coordinate. Finally, using an application for curve fitting, the model achieves an empirical formula that can calculate the degree of spatial similarity using map scale change as the sole independent variable, and vice versa. This formula can be used to automate algorithms for point feature generalization and to determine when to terminate them during the generalization. 展开更多
关键词 Spatial similarity degree Map generalization Map scale change Point clouds Quantitative description Spatial similarity relations multi-scale map spaces Curve fitting method
下载PDF
Space station short-term mission planning using ontology modelling and time iteration 被引量:5
13
作者 Huijiao Bu Jin Zhang Yazhong Luo 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第2期407-421,共15页
This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time ... This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time of the astronauts properly. A domain model is developed by using the ontology theory to describe the concepts, constraints and relations of the planning domain formally, abstractly and normatively. A method based on time iteration is adopted to solve the short-term planning problem. Meanwhile, the resolving strategies are proposed to resolve different kinds of conflicts induced by the constraints of power, heat, resource, astronaut and relationship. The proposed approach is evaluated in a test case with fifteen missions, thirteen resources and three astronauts. The results show that the developed domain ontology model is reasonable, and the time iteration method using the proposed resolving strategies can successfully obtain the plan satisfying all considered constraints. 展开更多
关键词 space station mission planning ontology modelling time iteration
下载PDF
A Method for Improving Power Distribution Characteristics of Space Time Block Codes 被引量:3
14
作者 Vahid Abbasi Mahrokh GShayesteh 《China Communications》 SCIE CSCD 2020年第6期223-234,共12页
Improving power distribution characteristics of space time block codes(STBCs),namely peak to average power ratio(PAPR),average to minimum power ratio(Ave/min),and probability of transmitting"zero"by antenna,... Improving power distribution characteristics of space time block codes(STBCs),namely peak to average power ratio(PAPR),average to minimum power ratio(Ave/min),and probability of transmitting"zero"by antenna,makes easier their practical implementation.To this end,this study proposes to multiply full diversity STB C with a non-singular matrix in multiple input multiple output(MIMO)or multiple input single output(MISO)systems with linear or maximum likelihood(ML)receivers.It is proved that the obtained code achieves full diversity and the order of detection complexity does not change.The proposed method is applied to different types of STBCs.The bit error rate(BER)and power distribution characteristics of the new codes demonstrate the superiority of the introduced method.Further,lower and upper bounds on the BER of the obtained STBCs are derived for all receivers.The proposed method provides trade-off among PAPR,spectral efficiency,energy efficiency,and BER. 展开更多
关键词 full diversity linear receiver maximum likelihood peak to average power ratio power distribution space time block codes
下载PDF
Physics of Clocks in Absolute Space-Time 被引量:3
15
作者 Edwin Eugene Klingman 《Journal of Modern Physics》 2020年第12期1950-1968,共19页
20th century physics experimentally established beyond doubt the fact that moving clocks read differently from “static” clocks. This fact is typically interpreted as support for special relativity. On the other hand... 20th century physics experimentally established beyond doubt the fact that moving clocks read differently from “static” clocks. This fact is typically interpreted as support for special relativity. On the other hand, the same century produced proof that clocks at various locations in the gravitational field also read differently, and this fact is explained by general relativity, which is, in general, not Lorentz transformable. This paper establishes a common framework for the physics of clocks in these different situations. 展开更多
关键词 RELATIVITY time Dilation space-time Ontology Clock Slowdown Inertial Clocks Absolute space and time Inertial Mass Covariance Principle Ideal Clocks
下载PDF
Benchmarking of two three-dimensional numerical models in time/space domain to predict railway-induced ground vibrations 被引量:2
16
作者 Jesus Fernandez-Ruiz Luis E.Medina Rodriguez +1 位作者 Pedro Alves Costa Margarita Martinez-Diaz 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第1期245-256,共12页
In the last 30 years,the scientific community has developed and proposed different models and numerical approaches for the study of vibrations induced by railway traffic.Most of them are formulated in the frequency/wa... In the last 30 years,the scientific community has developed and proposed different models and numerical approaches for the study of vibrations induced by railway traffic.Most of them are formulated in the frequency/wave number domain and with a 2.5D approach.Three-dimensional numerical models formulated in the time/space domain are less frequently used,mainly due to their high computational cost.Notwithstanding,these models present very attractive characteristics,such as the possibility of considering nonlinear behaviors or the modelling of excess pore pressure and non-homogeneous and non-periodic geometries in the longitudinal direction of the track.In this study,two 3D numerical approaches formulated in the time/space domain are compared and experimentally validated.The first one consists of a finite element approach and the second one of a finite difference approach.The experimental validation in an actual case situated in Carregado(Portugal)shows an acceptable fitting between the numerical results and the actual measurements for both models.However,there are some differences among them.This study therefore includes some recommendations for their use in practical soil dynamics and geotechnical engineering. 展开更多
关键词 railway vibrations time/space domain 3D numerical model finite difference method implicit finite element method
下载PDF
Design and Analysis of Spatial Modulation Based Orthogonal Time Frequency Space System 被引量:3
17
作者 Yingchao Yang Zhiquan Bai +4 位作者 Ke Pang Piming Ma Haixia Zhang Xinghai Yang Dongfeng Yuan 《China Communications》 SCIE CSCD 2021年第8期209-223,共15页
In this paper,we design a spatial modulation based orthogonal time frequency space(SMOTFS)system to achieve improved transmission reliability and meet the high transmission rate and highspeed demands of future mobile ... In this paper,we design a spatial modulation based orthogonal time frequency space(SMOTFS)system to achieve improved transmission reliability and meet the high transmission rate and highspeed demands of future mobile communications,which fully utilizes the characteristics of spatial modulation(SM)and orthogonal time frequency space(OTFS)transmission.The detailed system design and signal processing of the SM-OTFS system have been presented.The closed-form expressions of the average symbol error rate(ASER)and average bit error rate(ABER)of the SM-OTFS system have been derived over the delay-Doppler channel with the help of the union bounding technique and moment-generating function(MGF).Meanwhile,the system complexity has been evaluated.Numerical results verify the correctness of the theoretical ASER and ABER analysis of the SM-OTFS system in the high signal-to-noise ratio(SNR)regions and also show that the SM-OTFS system outperforms the traditional SM based orthogonal frequency division multiplexing(SM-OFDM)system with limited complexity increase under mobile conditions,especially in high mobility scenarios. 展开更多
关键词 orthogonal time frequency space(OTFS) spatial modulation based OTFS(SM-OTFS) delay-Doppler domain average symbol error rate(ASER) average bit error rate(ABER)
下载PDF
E-Infinity Dualities, Discontinuous Spacetimes, Xonic Quantum Physics and the Decisive Experiment 被引量:2
18
作者 Jean-Paul Auffray 《Journal of Modern Physics》 2014年第15期1427-1436,共10页
Using powerful concepts and tools borrowed from the seminal arsenal connecting physics fundamentals with esoteric set theoretical operations developed in recent years by Alexandria E-infinity theoretician M. S. El Nas... Using powerful concepts and tools borrowed from the seminal arsenal connecting physics fundamentals with esoteric set theoretical operations developed in recent years by Alexandria E-infinity theoretician M. S. El Naschie, this paper explores the deep implications of some of the dualities Dr El Naschie has identified and analyzed in his exposes, connecting them with our own Xonic Quantum Physics (XQP) which places dynamical action rather than spacetime and energy at the core of the System of the World. 展开更多
关键词 E-INFINITY El Naschie space time spacetime Topology CANTOR Sets Energy Xon Xonic Quantum Physics PLANCK Scale Dirac Electron
下载PDF
Euclidean Model of Space and Time 被引量:1
19
作者 Radovan Machotka 《Journal of Modern Physics》 2018年第6期1215-1249,共35页
The aim of this work is to show that the currently widely accepted geometrical model of space and time based on the works of Einstein and Minkowski is not unique. The work presents an alternative geometrical model of ... The aim of this work is to show that the currently widely accepted geometrical model of space and time based on the works of Einstein and Minkowski is not unique. The work presents an alternative geometrical model of space and time, a model which, unlike the current one, is based solely on Euclidean geometry. In the new model, the pseudo-Euclidean spacetime is replaced with a specific subset of four-dimensional Euclidean space. The work shows that four-dimensional Euclidean space allows explanation of known relativistic effects that are now explained in pseudo-Euclidean spacetime by Einstein’s Special Theory of Relativity (STR). It also shows simple geometric-kinematical nature of known relativistic phenomena and among others explains why we cannot travel backward in time. The new solution is named the Euclidean Model of Space and Time (EMST). 展开更多
关键词 SPECIAL Theory of RELATIVITY Euclidean space Four-Dimensional space time DILATION LENGTH CONTRACTION
下载PDF
ON MARKOV CHAINS IN SPACE-TIME RANDOM ENVIRONMENTS 被引量:7
20
作者 胡迪鹤 胡晓予 《Acta Mathematica Scientia》 SCIE CSCD 2009年第1期1-10,共10页
In Section 1, the authors establish the models of two kinds of Markov chains in space-time random environments (MCSTRE and MCSTRE(+)) with abstract state space. In Section 2, the authors construct a MCSTRE and a MCSTR... In Section 1, the authors establish the models of two kinds of Markov chains in space-time random environments (MCSTRE and MCSTRE(+)) with abstract state space. In Section 2, the authors construct a MCSTRE and a MCSTRE(+) by an initial distribution Φ and a random Markov kernel (RMK) p(γ). In Section 3, the authors es-tablish several equivalence theorems on MCSTRE and MCSTRE(+). Finally, the authors give two very important examples of MCMSTRE, the random walk in spce-time random environment and the Markov br... 展开更多
关键词 Random Markov kernel Markov chain in space-time random environemnt random walk in space-time random environment Markov branching chain in space-time random environment
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部