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Thermodynamics of charged AdS black hole surrounded by quintessence in restricted phase space
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作者 Siyu Jian Siying Long +1 位作者 Juhua Chen Yongjiu Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期205-212,共8页
We study thermodynamics of charged AdS black hole surrounded by quintessence in a new formalism which is called the restricted phase space thermodynamics.This context is based on Visser’s holographic thermodynamics w... We study thermodynamics of charged AdS black hole surrounded by quintessence in a new formalism which is called the restricted phase space thermodynamics.This context is based on Visser’s holographic thermodynamics with a fixed antide Sitter radius and a variable Newton constant.The conjugate variables,central charge C and the chemical potential m,are introduced as a new pair of thermodynamic variables.We find that the iso-e-charge T-S curve becomes non-monotonic when Q<Q_(c).Correspondingly,the F-T curve exhibits a swallow tail structure.This behavior is considered as a van der Waals-like phase transition.As the value of b related to the energy density of Kiselev’s fluid becomes larger,the critical temperature T_(c)will decrease.Thus,the van derWaals-like phase transition will occur at lower temperature.There is always a non-quilibrium transition from a small unstable black hole to a large stable black hole state in the isocoltage T-S process.There exist a maximum and a Hawking-Page phase transition points in theμ-C plane.As the value of b related to Kiselev’s fluid becomes larger,the Hawking-Page phase transition will occur at lower temperature in the isovoltageμ-T process.For other values of the state parameterω,there also exists van der Waals-like phase transition. 展开更多
关键词 Reissner-Nordstrom qAdS black hole restricted phase space variable Newton constant
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Heterogeneous information phase space reconstruction and stability prediction of filling body–surrounding rock combination
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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
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Prediction of seawater pH by bidirectional gated recurrent neural network with attention under phase space reconstruction:case study of the coastal waters of Beihai,China
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作者 Chongxuan Xu Ying Chen +2 位作者 Xueliang Zhao Wenyang Song Xiao Li 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第10期97-107,共11页
Marine life is very sensitive to changes in pH.Even slight changes can cause ecosystems to collapse.Therefore,understanding the future pH of seawater is of great significance for the protection of the marine environme... Marine life is very sensitive to changes in pH.Even slight changes can cause ecosystems to collapse.Therefore,understanding the future pH of seawater is of great significance for the protection of the marine environment.At present,the monitoring method of seawater pH has been matured.However,how to accurately predict future changes has been lacking effective solutions.Based on this,the model of bidirectional gated recurrent neural network with multi-headed self-attention based on improved complete ensemble empirical mode decomposition with adaptive noise combined with phase space reconstruction(ICPBGA)is proposed to achieve seawater pH prediction.To verify the validity of this model,pH data of two monitoring sites in the coastal sea area of Beihai,China are selected to verify the effect.At the same time,the ICPBGA model is compared with other excellent models for predicting chaotic time series,and root mean square error(RMSE),mean absolute error(MAE),mean absolute percentage error(MAPE),and coefficient of determination(R2)are used as performance evaluation indicators.The R2 of the ICPBGA model at Sites 1 and 2 are above 0.9,and the prediction errors are also the smallest.The results show that the ICPBGA model has a wide range of applicability and the most satisfactory prediction effect.The prediction method in this paper can be further expanded and used to predict other marine environmental indicators. 展开更多
关键词 seawater pH prediction Bi-gated recurrent neural(GRU)model phase space reconstruction attention mechanism improved complete ensemble empirical mode decomposition with adaptive noise
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Explanation of Relation between Wave Function and Probability Density Based on Quantum Mechanics in Phase Space
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作者 Chol Jong Jin-Sim Kim +1 位作者 Shin-Hyok Jon Son-Il Jo 《World Journal of Mechanics》 2023年第1期20-72,共53页
The main problem of quantum mechanics is to elucidate why the probability density is the modulus square of wave function. For the purpose of solving this problem, we explored the possibility of deducing the fundamenta... The main problem of quantum mechanics is to elucidate why the probability density is the modulus square of wave function. For the purpose of solving this problem, we explored the possibility of deducing the fundamental equation of quantum mechanics by starting with the probability density. To do so, it is necessary to formulate a new theory of quantum mechanics distinguished from the previous ones. Our investigation shows that it is possible to construct quantum mechanics in phase space as an alternative autonomous formulation and such a possibility enables us to study quantum mechanics by starting with the probability density rather than the wave function. This direction of research is contrary to configuration-space formulation of quantum mechanics starting with the wave function. Our work leads to a full understanding of the wave function as the both mathematically and physically sufficient representation of quantum-mechanical state which supplements information on quantum state given solely by the probability density with phase information on quantum state. The final result of our work is that quantum mechanics in phase space satisfactorily elucidates the relation between the wave function and the probability density by using the consistent procedure starting with the probability density, thus corroborating the ontological interpretation of the wave function and withdrawing a main assumption of quantum mechanics. 展开更多
关键词 Quantum Ensemble Theory Quantum Mechanics In phase space Wave Function Probability Density Schrödinger Equation
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ON A UNIVERSAL INEQUALITY FOR APPROXIMATE PHASE ISOMETRIES
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作者 戴端旭 阙海新 +1 位作者 孙龙发 郑本拓 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期823-838,共16页
Let X and Y be two normed spaces.Let U be a non-principal ultrafilter on N.Let g:X→Y be a standard ε-phase isometry for someε≥ 0,i.e.,g(0)=0,and for all u.v ∈ X,||‖g(u)+g(v)‖±‖g(u)-g(v)‖|-|‖u+v‖±... Let X and Y be two normed spaces.Let U be a non-principal ultrafilter on N.Let g:X→Y be a standard ε-phase isometry for someε≥ 0,i.e.,g(0)=0,and for all u.v ∈ X,||‖g(u)+g(v)‖±‖g(u)-g(v)‖|-|‖u+v‖±‖u-v‖| |≤ε.The mapping g is said to be a phase isometry provided that ε=0.In this paper,we show the following universal inequality of g:for each u^(*) ∈ w^(*)-exp ‖u^(*)‖B_(x^(*)),there exist a phase function σ_(u^(*)):X→{-1,1} and φ ∈ Y^(*) with ‖φ‖=‖u^(*)‖≡α satisfying that|(u^(*),u)-σ_(u^(*))(u)<φ,g(u)>)|≤5/2εα,for all u ∈ X.In particular,let X be a smooth Banach space.Then we show the following:(1) the universal inequality holds for all u^(*) ∈ X^(*);(2) the constant 5/2 can be reduced to 3/2 provided that Y~*is strictly convex;(3) the existence of such a g implies the existence of a phase isometryΘ:X→Y such that■ provided that Y^(**) has the w^(*)-Kadec-Klee property(for example,Y is both reflexive and locally uniformly convex). 展开更多
关键词 ε-phase isometry phase isometry Banach space
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Microwave-Assisted Au and Ag Nanoparticle Synthesis: An Energy Phase-Space Projection Analysis
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作者 Victor J. Law Denis P. Dowling 《American Journal of Analytical Chemistry》 CAS 2023年第4期149-174,共26页
Microwave-assisted synthesis of gold and silver nanoparticles, as a function of Green Chemistry, non Green Chemistry, and four applicator types are reported. The applicator types are Domestic microwave ovens, commerci... Microwave-assisted synthesis of gold and silver nanoparticles, as a function of Green Chemistry, non Green Chemistry, and four applicator types are reported. The applicator types are Domestic microwave ovens, commercial temperature controlled microwave chemistry ovens (TCMC), digesters, and axial field helical antennae. For each of these microwave applicators the process energy budget where estimated (Watts multiplied by process time = kJ) and energy density (applied energy divided by suspension volume = kJ·ml<sup>-1</sup>) range between 180 ± 176.8 kJ, and 79.5 ± 79 kJ·ml<sup>-1</sup>, respectively. The axial field helical field an-tenna applicator is found to be the most energy efficient (0.253 kJ·m<sup>-1</sup> per kJ, at 36 W). Followed by microwave ovens (4.47 ± 3.9 kJ·ml<sup>-1</sup> per 76.83 ± 39 kJ), and TCMC ovens (2.86 ± 2.3 kJ·m<sup>-1</sup> per 343 ± 321.5 kJ). The digester applicators have the least energy efficiency (36.2 ± 50.7 kJ·m<sup>-1</sup> per 1010 ± 620 kJ). A comparison with reconstructed ‘non-thermal’ microwave oven inactivation microorganism experiments yields a power-law signature of n = 0.846 (R<sup>2</sup> = 0.7923) four orders of magnitude. The paper provides a discussion on the Au and Ag nanoparticle chemistry and bio-chemistry synthesis aspects of the microwave applicator energy datasets and variation within each dataset. The visual and analytical approach within the energy phase-space projection enables a nanoparticle synthesis route to be systematically characterized, and where changes to the synthesis are to be mapped and compared directly with historical datasets. In order to help identify lower cost nanoparticle synthesis, in addition to potentially reduce synthesis energy to routes informed changes to potentially reduce synthesis energy budget, along with nanoparticle morphology and yield. 展开更多
关键词 Turkevich Microwave-Assisted Synthesis Ag AU HYDROXYAPATITE Nanoparticle FUNCTIONALIZATION Energy phase-space Projection
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Neural network forecasting model based on phase space re-construction in water yield of mine
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作者 刘卫林 董增川 +1 位作者 陈南祥 曹连海 《Journal of Coal Science & Engineering(China)》 2007年第2期175-178,共4页
The neutral network forecasting model based on the phase space reconstruction was proposed. First, through reconstructing the phase space, the time series of single variable was done excursion and expanded into multi-... The neutral network forecasting model based on the phase space reconstruction was proposed. First, through reconstructing the phase space, the time series of single variable was done excursion and expanded into multi- dimension series which included the ergodic information and more rich information could be excavated. Then, on the basis of the embedding dimension of the time series, the structure form of neutral network was constructed, of which the node number in input layer was the embedding dimension of the time series minus 1, and the node number in output layers was 1. Finally, as an example, the model was applied for water yield of mine forecasting. The result shows that the model has good fitting accuracy and forecasting precision. 展开更多
关键词 neural network forecasting model phase space reconstruction water yield ofmine CHAOS
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Spacem占位器专用骨水泥联合敏感抗生素在全膝关节置换术后感染二期翻修中的应用效果
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作者 宋维 杨武镠 +1 位作者 刘泉 李洋 《世界复合医学(中英文)》 2024年第9期120-123,共4页
目的探讨全膝关节置换术后感染二期翻修中应用敏感抗生素联合Spacem占位器专用骨水泥治疗的效果。方法选择2022年1月—2023年12月黔西市人民医院收治的60例全膝关节置换术后感染患者作为研究对象,根据治疗方法的不同将其分为对照组和观... 目的探讨全膝关节置换术后感染二期翻修中应用敏感抗生素联合Spacem占位器专用骨水泥治疗的效果。方法选择2022年1月—2023年12月黔西市人民医院收治的60例全膝关节置换术后感染患者作为研究对象,根据治疗方法的不同将其分为对照组和观察组,各30例。对照组采用传统方法治疗,观察组采用Spacem占位器专用骨水泥联合敏感抗生素治疗。比较两组炎症指标、临床疗效和术后并发症总发生率。结果治疗前,两组患者白细胞计数、中性粒细胞比例对比,差异无统计学意义(P均>0.05)。治疗后,观察组患者白细胞计数为(5.74±0.83)×10~9/L,中性粒细胞比例为(42.34±2.05)%,低于对照组的(12.01±1.26)×10~9/L、(68.11±2.27)%,差异有统计学意义(t=8.254、9.361,P均<0.05)。观察组治疗总有效率高于对照组,术后并发症总发生率低于对照组,差异有统计学意义(P均<0.05)。结论Spacem占位器专用骨水泥联合敏感抗生素在全膝关节置换术后感染二期翻修中的应用效果显著,且安全性高。 展开更多
关键词 全膝关节置换术后感染 spacem占位器 骨水泥 敏感抗生素 二期翻修
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INTERNET TRAFFIC DATA FLOW FORECAST BY RBF NEURAL NETWORK BASED ON PHASE SPACE RECONSTRUCTION 被引量:4
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作者 陆锦军 王执铨 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第4期316-322,共7页
Characteristics of the Internet traffic data flow are studied based on the chaos theory. A phase space that is isometric with the network dynamic system is reconstructed by using the single variable time series of a n... Characteristics of the Internet traffic data flow are studied based on the chaos theory. A phase space that is isometric with the network dynamic system is reconstructed by using the single variable time series of a network flow. Some parameters, such as the correlative dimension and the Lyapunov exponent are calculated, and the chaos characteristic is proved to exist in Internet traffic data flows. A neural network model is construct- ed based on radial basis function (RBF) to forecast actual Internet traffic data flow. Simulation results show that, compared with other forecasts of the forward-feedback neural network, the forecast of the RBF neural network based on the chaos theory has faster learning capacity and higher forecasting accuracy. 展开更多
关键词 chaos theory phase space reeonstruction Lyapunov exponent tnternet data flow radial basis function neural network
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New conserved quantities of Noether-Mei symmetry of mechanical system in phase space 被引量:4
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作者 方建会 刘仰魁 张小妮 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第6期1962-1966,共5页
This paper studies two new types of conserved quantities deduced by Noether Mei symmetry of mechanical system in phase space. The definition and criterion of Noether Mei symmetry for the system are given. A coordinati... This paper studies two new types of conserved quantities deduced by Noether Mei symmetry of mechanical system in phase space. The definition and criterion of Noether Mei symmetry for the system are given. A coordination function is introduced, and the conditions under which the Noether- Mei symmetry leads to the two types of conserved quantities and the forms of the two types of conserved quantities are obtained. An illustrative example is given. The coordination function can be selected according to the demand for finding the gauge function, and the choice of the coordination function has multiformity, so more conserved quantities deduced from Noether Mei symmetry of mechanical system can be obtained. 展开更多
关键词 mechanical system phase space Noether-Mei symmetry new conserved quantity
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Prediction of elevator traffic flow based on SVM and phase space reconstruction 被引量:4
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作者 唐海燕 齐维贵 丁宝 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第3期111-114,共4页
To make elevator group control system better follow the change of elevator traffic flow (ETF) in order to adjust the control strategy,the prediction method of support vector machine (SVM) in combination with phase spa... To make elevator group control system better follow the change of elevator traffic flow (ETF) in order to adjust the control strategy,the prediction method of support vector machine (SVM) in combination with phase space reconstruction has been proposed for ETF.Firstly,the phase space reconstruction for elevator traffic flow time series (ETFTS) is processed.Secondly,the small data set method is applied to calculate the largest Lyapunov exponent to judge the chaotic property of ETF.Then prediction model of ETFTS based on SVM is founded.Finally,the method is applied to predict the time series for the incoming and outgoing passenger flow respectively using ETF data collected in some building.Meanwhile,it is compared with RBF neural network model.Simulation results show that the trend of factual traffic flow is better followed by predictive traffic flow.SVM algorithm has much better prediction performance.The fitting and prediction of ETF with better effect are realized. 展开更多
关键词 support vector machine phase space reconstruction prediction of elevator traffic flow RBF neural network
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Noether-Mei Symmetry of Mechanical System in Phase Space 被引量:4
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作者 FANG Jian-Hui WANG Peng DING Ning 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第5期882-884,共3页
In this paper, a new kind of symmetry and its conserved quantities of a mechanical system in phase space are studied. The definition of this new symmetry, i,e., a Noether-Mei symmetry, is presented, and the criterion ... In this paper, a new kind of symmetry and its conserved quantities of a mechanical system in phase space are studied. The definition of this new symmetry, i,e., a Noether-Mei symmetry, is presented, and the criterion of this symmetry is also given. The Noether conserved quantity and the Mei conserved quantity deduced from the Noether-Mei symmetry of the system are obtained. Finally, two examples are given to illustrate the Bpplication of the results. 展开更多
关键词 Noether-Mei symmetry conserved quantity mechanical system phase space
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Phase space reconstruction of chaotic dynamical system based on wavelet decomposition 被引量:2
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作者 游荣义 黄晓菁 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第2期114-118,共5页
In view of the disadvantages of the traditional phase space reconstruction method, this paper presents the method of phase space reconstruction based on the wavelet decomposition and indicates that the wavelet decompo... In view of the disadvantages of the traditional phase space reconstruction method, this paper presents the method of phase space reconstruction based on the wavelet decomposition and indicates that the wavelet decomposition of chaotic dynamical system is essentially a projection of chaotic attractor on the axes of space opened by the wavelet filter vectors, which corresponds to the time-delayed embedding method of phase space reconstruction proposed by Packard and Takens. The experimental results show that, the structure of dynamical trajectory of chaotic system on the wavelet space is much similar to the original system, and the nonlinear invariants such as correlation dimension, Lyapunov exponent and Kolmogorov entropy are still reserved. It demonstrates that wavelet decomposition is effective for characterizing chaotic dynamical system. 展开更多
关键词 chaotic dynamical system phase space reconstruction wavelet decomposition
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Degradation Process of Coated Tinplate by Phase Space Reconstruction Theory 被引量:5
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作者 石江波 夏大海 +2 位作者 王吉会 周超 刘彦宏 《Transactions of Tianjin University》 EI CAS 2013年第2期92-97,共6页
The degradation process of organosol coated tinplate in beverage was investigated by electrochemical noise (EN) technique combined with morphology characterization.EN data were analyzed using phase space reconstructio... The degradation process of organosol coated tinplate in beverage was investigated by electrochemical noise (EN) technique combined with morphology characterization.EN data were analyzed using phase space reconstruction theory.With the correlation dimensions obtained from the phase space reconstruction,the chaotic behavior of EN was quantitatively evaluated.The results show that both electrochemical potential noise (EPN) and electrochemical current noise (ECN) have chaotic properties.The correlation dimensions of EPN increase with corrosion extent,while those of ECN seem nearly unchanged.The increased correlation dimensions of EPN during the degradation process are associated with the increased susceptibility to local corrosion. 展开更多
关键词 phase space reconstruction CHAOS electrochemical potential noise electrochemical current noise correlation dimension organic coating
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Transverse phase space reconstruction study in Shanghai soft X-ray FEL facility 被引量:1
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作者 Qing-Lin Yu Duan Gu +1 位作者 Meng Zhang Ming-Hua Zhao 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第1期9-15,共7页
Phase space is one of the most important parameters used to describe beam properties. Computer tomography, as a method for reconstructing phase space and measuring beam emittance, has been used in many accelerators ov... Phase space is one of the most important parameters used to describe beam properties. Computer tomography, as a method for reconstructing phase space and measuring beam emittance, has been used in many accelerators over the past few decades. In this paper, we demonstrate a transverse phase space reconstruction study in the Shanghai soft X-ray free electron laser facility. First,we discuss the basic principles of phase space reconstruction and the advantage of reconstructing beam distribution in normalized phase space. Then, the phase space reconstruction results by different computer tomography methods based on the maximum entropy(MENT) algorithm and the filtered back projection algorithm in normalized phase space are presented. The simulation results indicate that,with proper configuration of the phase advance between adjacent screens, the MENT algorithm is feasible and has good efficiency. The beam emittance and Twiss parameters are also calculated using the reconstructed phase space. 展开更多
关键词 EMITTANCE phase space RECONSTRUCTION MENT algorithm SXFEL
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A New Kind of Two-Fold Integration Transformation in Phase Space and Its Uses in Weyl Ordering of Operators 被引量:3
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作者 FAN Hong-Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第10期935-937,共3页
We propose a new two-fold integration transformation in p-q phase space∫∫^∞-∞dpdq/π e^2i(p-x)(q-y)f(p,q)≡G(x,y),which possesses some well-behaved transformation properties. We apply this transformation t... We propose a new two-fold integration transformation in p-q phase space∫∫^∞-∞dpdq/π e^2i(p-x)(q-y)f(p,q)≡G(x,y),which possesses some well-behaved transformation properties. We apply this transformation to the Weyl ordering of operators, especially those Q-P ordered and P-Q ordered operators. 展开更多
关键词 new two-fold integration transform phase space Weyl ordering of operators
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Study on resource quantity of surface water based on phase space reconstruction and neural network 被引量:5
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作者 曹连海 郝仕龙 陈南祥 《Journal of Coal Science & Engineering(China)》 2006年第1期39-42,共4页
Proposed a new method to disclose the complicated non-linearity structure of the water-resource system, introducing chaos theory into the hydrology and water resources field, and combined with the chaos theory and art... Proposed a new method to disclose the complicated non-linearity structure of the water-resource system, introducing chaos theory into the hydrology and water resources field, and combined with the chaos theory and artificial neural networks. Training data construction and networks structure were determined by the phase space reconstruction, and establishing nonlinear relationship of phase points with neural networks, the forecasting model of the resource quantity of the surface water was brought forward. The keystone of the way and the detailed arithmetic of the network training were given. The example shows that the model has highly forecasting precision. 展开更多
关键词 phase space reconstruction neural network resource quantity of the surface water forecasting model
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A Forecasting Model of Vector Similarity in Phase Space for Flood and Drought over the Huanghe-Huaihe-Haihe Plain in China 被引量:1
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作者 周家斌 王允宽 +1 位作者 杨桂英 吴津生 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1994年第2期224-229,共6页
To represent well the characteristics of temporal and spatial distributions, chart of 3-dekad moving total precipitation is proposed in this paper first. Then this kind of chart is expanded in terms of Chebyshev polyn... To represent well the characteristics of temporal and spatial distributions, chart of 3-dekad moving total precipitation is proposed in this paper first. Then this kind of chart is expanded in terms of Chebyshev polynomial at irregular grids, and the quantitative representation of precipitation is got. Finally the Chebyshev coefficients are forecasted by using the forecasting method of vector similarity in phase space proposed by Zhou (1992). Using above mentioned procedures temporal and spatial distributions of precipitation over the Huanghe-- Huaihe-- H aihe Plain in China are forecasted. 展开更多
关键词 3-dekad moving total precipitation Chebyshev expansion Forecasting method phase space
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Analysis of dynamic of two-phase flow in small channel based on phase space reconstruction combined with data reduction sub-frequency band wavelet 被引量:3
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作者 李洪伟 刘君鹏 +2 位作者 李涛 周云龙 孙斌 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第6期1017-1026,共10页
A new method of nonlinear analysis is established by combining phase space reconstruction and data reduction sub-frequency band wavelet. This method is applied to two types of chaotic dynamic systems(Lorenz and Rssler... A new method of nonlinear analysis is established by combining phase space reconstruction and data reduction sub-frequency band wavelet. This method is applied to two types of chaotic dynamic systems(Lorenz and Rssler) to examine the anti-noise ability for complex systems. Results show that the nonlinear dynamic system analysis method resists noise and reveals the internal dynamics of a weak signal from noise pollution. On this basis, the vertical upward gas–liquid two-phase flow in a 2 mm × 0.81 mm small rectangular channel is investigated. The frequency and energy distributions of the main oscillation mode are revealed by analyzing the time–frequency spectra of the pressure signals of different flow patterns. The positive power spectral density of singular-value frequency entropy and the damping ratio are extracted to characterize the evolution of flow patterns and achieve accurate recognition of different vertical upward gas–liquid flow patterns(bubbly flow:100%, slug flow: 92%, churn flow: 96%, annular flow: 100%). The proposed analysis method will enrich the dynamics theory of multi-phase flow in small channel. 展开更多
关键词 Small channel two-phase flow Flow pattern dynamics phase space reconstruction Data reduction sub-frequency band wavelet
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Classification of power quality combined disturbances based on phase space reconstruction and support vector machines 被引量:3
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作者 Zhi-yong LI Wei-lin WU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第2期173-181,共9页
Power Quality (PQ) combined disturbances become common along with ubiquity of voltage flickers and harmonics. This paper presents a novel approach to classify the different patterns of PQ combined disturbances. The cl... Power Quality (PQ) combined disturbances become common along with ubiquity of voltage flickers and harmonics. This paper presents a novel approach to classify the different patterns of PQ combined disturbances. The classification system consists of two parts, namely the feature extraction and the automatic recognition. In the feature extraction stage, Phase Space Reconstruction (PSR), a time series analysis tool, is utilized to construct disturbance signal trajectories. For these trajectories, several indices are proposed to form the feature vectors. Support Vector Machines (SVMs) are then implemented to recognize the different patterns and to evaluate the efficiencies. The types of disturbances discussed include a combination of short-term dis-turbances (voltage sags, swells) and long-term disturbances (flickers, harmonics), as well as their homologous single ones. The feasibilities of the proposed approach are verified by simulation with thousands of PQ events. Comparison studies based on Wavelet Transform (WT) and Artificial Neural Network (ANN) are also reported to show its advantages. 展开更多
关键词 Power Quality (PQ) Combined disturbance CLASSIFICATION phase space Reconstruction (PSR) Support Vector Machines (SVMs)
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