Knowledge of the culture difference in inter-cultural communicative is of primary importance. It is so in Sino-American communication, especially in speech, one of the two means of communication through language, with...Knowledge of the culture difference in inter-cultural communicative is of primary importance. It is so in Sino-American communication, especially in speech, one of the two means of communication through language, with the other being writing. American and Chinese, brought up in different cultures, have different speech styles. Diversity in speech styles not only involves communication through verbal speech, but also through such non-verbal acts as kinesics, proxemics, and paralinguistic elements. Here the speech styles in the two cultures, American and Chinese, are contrasted with examples from a cultural perspective.展开更多
Based on our previously pulse-coupled integrate-and-fire neuron model in small world networks, we investigate the effects of different connectivity topologies on complex behavior of electroencephalographic-like signal...Based on our previously pulse-coupled integrate-and-fire neuron model in small world networks, we investigate the effects of different connectivity topologies on complex behavior of electroencephalographic-like signals produced by this model. We show that several times series analysis methods that are often used for analyzing complex behavior of electroencephalographic-like signals, such as reconstruction of the phase space, correlation dimension, fractal dimension, and the Hurst exponent within the rescaled range analysis (R/S). We lind that the different connectivity topologies lead to different dynamical behaviors in models of integrate-and-fire neurons.展开更多
The buckling behavior of single layer space structure is very sensitive. The joint rigidity, moreover, is one of the main factors of stability which may determine the entire failure behavior. Thus, the reasonable stif...The buckling behavior of single layer space structure is very sensitive. The joint rigidity, moreover, is one of the main factors of stability which may determine the entire failure behavior. Thus, the reasonable stiffness of joint system, which is neither total pin assumption nor perfect fix condition, is very important to apply to the real single layer space one. Therefore, the purpose of this work was to investigate the buckling behavior of single layer space structure, using the development of the upgraded stiffness matrix for the joint rigidity. To derive tangential stiffness matrix, a displacement function was assumed using translational and rotational displacement at the node. The geometrical nonlinear analysis was simulated not only with perfect model but also with imperfect one. As a result, the one and two free nodal numerical models were investigated using derived stiffness matrix. It was figured out that the buckling load increases in proportion to joint rigidity with rise-span ratio. The stability of numerical model is very sensitive with the initial imperfection, responding of bifurcation in the structure.展开更多
The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating condi...The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating conditions of space bearings. A traction coefficient calculation model was presented. The rheological property and rheological parameters of the lubricant at a low oil inlet temperature were analyzed based on the Tevaarwerk-Johnson model. The results showed that the lubricating oil No. 4116 was sensitive to the rolling speed and had lower sensitivity to the normal load. This lubricating oil is more suitable for applications under high speed when it is used below 0 ℃. It behaves as an elastic-plastic fluid operating below 0 ℃. Both the average limiting shear stress and the average elastic shear modulus have a negative correlation with the rolling speed and oil inlet temperature and have a positive correlation with the normal load.展开更多
The paper takes the relation between soundscapes and power struggles as its problem area and focuses on the role of music that is performed in public protests. It argues that music and street performances are conceive...The paper takes the relation between soundscapes and power struggles as its problem area and focuses on the role of music that is performed in public protests. It argues that music and street performances are conceived and therefore utilised as sonic acts of political struggle in urban realm. Starting with a general understanding of hearing mechanisms, the study elucidates the relationships among territoriality of soundscape, identity construction, social segregation and polarisation, and finally, power struggle. Within the framework of the intersection area of these concepts, the paper discusses the processes of politisation of soundscape through music as a form of protest event that is performed in public realm. Throughout the paper, it is focused on the significant cases of public protests as well as political events that occured in public space. The main emphasis is on the use of sound technologies to impose power on masses of people. The paper tackles the question of how the salient characteristics of soundscape are sonically adopted as means for counter-political acts in public realm.展开更多
The effect of Batroxobin on spatial memory disorder of left temporal ischemic rats and the expression of HSP32 and HSP70 were investigated with Morri`s water maze and immunohistochemistry methods. The results show... The effect of Batroxobin on spatial memory disorder of left temporal ischemic rats and the expression of HSP32 and HSP70 were investigated with Morri`s water maze and immunohistochemistry methods. The results showed that the mean reaction time and distance of temporal ischemic rats in searching a goal were significantly longer than those of the sham-operated rats and at the same time HSP32 and HSP70 expression of left temporal ischemic region in rats was significantly increased as compared with the sham-operated rats. However, the mean reaction time and distance of the Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of HSP32 and HSP70 immune reactive cells of Batroxobin-treated rats was also less than that of the ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats; and the down-regulation of the expression of HSP32 and HSP70 is probably related to the attenuation of ischemic injury.展开更多
Traditionally, microclimate, behavior and space design are characterized by a separation among climatologists, behavior researchers and designers. It is also unrealizable to apply the research results to the space des...Traditionally, microclimate, behavior and space design are characterized by a separation among climatologists, behavior researchers and designers. It is also unrealizable to apply the research results to the space design because of the gap created by the interdisciplinarity. In addition, although the relationships among space form, urban microclimate and people are intuitively understood, there are still not reasonable predictions on how a space affects the microclimate, and how the microclimate and space will affect people's sensation and behavior. By recording the microclimate and people's responses, this paper discusses the relationship between people's sensation and microclimate as well as people's behavior and open space in a busy downtown pedestrian street during hot summer. The research finds that shade plays a crucial role in outdoor comfort. All of the other objectively comfortable and acceptable microclimates differ significantly different shade situation. Simultaneously, space contradiction can be considered an essential factor for spatial utilization. This paper also provides proposal on canyon open space design based on this case study.展开更多
The novel Ragtime, written by the contemporary American writer Edgar Lawrence Doctorow, imaginatively reconstructs the urban space in the Progressive Era. In the period of social transformation and change, all kinds o...The novel Ragtime, written by the contemporary American writer Edgar Lawrence Doctorow, imaginatively reconstructs the urban space in the Progressive Era. In the period of social transformation and change, all kinds of contradictions in New York City are becoming increasingly acute. The division of space reflects the power discourse of different classes, races, and genders. The connection, extension and expansion of space promote the features of urban modernity and open up new patterns of social behavior and opportunities for survival, but cannot fundamentally alleviate the capitalist crisis. Spatial layout and distribution of the city are not only the reflection of social relations, but also the "time capsule", bearing the history of the city, and the writing of space offers a mirror for the author's emotion and value judgment.展开更多
This paper addresses new trends in quantitative geography research. Modern social science research--including economic and social geography--has in the past decades shown an increasing interest in micro-oriented behav...This paper addresses new trends in quantitative geography research. Modern social science research--including economic and social geography--has in the past decades shown an increasing interest in micro-oriented behaviour of actors. This is inter alia clearly reflected in SIMs (spatial interaction models), where discrete choice approaches have assumed a powerful position. This paper aims to provide in particular a concise review of micro-based research, with the aim to review the potential--but also the caveats---of micro models to map out human behaviour. In particular, attention will be devoted to interactive learning principles that shape individual decisions. Lessons from cognitive sciences will be put forward and illustrated, amongst others on the basis of computational neural networks or spatial econometric approaches. Particular attention will be paid to non-linear dynamic spatial models, amongst others, in the context of chaos theory and complexity science. The methodology of deductive reasoning under conditions of large data bases in studying human mobility will be questioned as well. In this context more extensive attention is given to ceteris paribus conditions and evolutionary thinking. The relevance of the paper will be illustrated by referring to various spatial applications in different disciplines and different application areas, e.g. in geography, regional science or urban economics.展开更多
Deep level donor's ionization behavior of passive film formed on the surface of stainless steel was investigated by Mott-Schottky plots. It is indicated that transformation process of deep level donors' ionization b...Deep level donor's ionization behavior of passive film formed on the surface of stainless steel was investigated by Mott-Schottky plots. It is indicated that transformation process of deep level donors' ionization behavior of passive film on surface of stainless steel can be divided into 4 stages with rising immersion time. At the initial immersion stage (10 min), Fe(II) located in the octahedral sites of the unit cell is not ionized and the deep level does not appear in Mott-Schottky plots. At the second stage (9-38 h), Fe(II) located in the octahedral sites starts to be ionized, which results in deep level donors' generation and density of deep level donors almost is constant with augmenting immersion time but the thickness of space charge layer is more and more thicker with rising immersion time. At the third stage (48 h-12 d), density of deep level donors rises with increasing immersion time and the thickness of passive films space charge layer decreases. At last stage (above 23 d), both the space charge layer's thickness and density of deep level donors are no longer changed with increasing immersion time. In the overall immersion stage, the shallow level donors' density is invariable all the time. The mechanism of deep level donor's ionization can be the generation of metal vacancies, which results in crystal lattice's aberration and the aberration energy urges the ionization of Fe( II ) in octahedral sites.展开更多
The end windings of generators are excited to vibrations due to electromagnetic forces which can cause severe damage (especially in case of resonance) and noise. To avoid this, it is important to predict the natural...The end windings of generators are excited to vibrations due to electromagnetic forces which can cause severe damage (especially in case of resonance) and noise. To avoid this, it is important to predict the natural frequencies and modes of the end windings with finite elements during the design process. Hence, a material model of the complete stator bar is necessary. This paper shows the development of such a material model. The composite structure of a stator bar is quite complex and makes it impossible to provide a quick calculation of the eigenvalues. That is the reason for using a suitable, homogeneously, geometry based solid model. Special attention was paid to the experimental determination of the material characteristics of the orthotropic composite space brackets. The numerical results have been evaluated against measurements. Eigenvalues, Young's modulus, and shear modulus have been experimentally investigated.展开更多
It is known that certain one parameter families of unimodal maps of the interval have a topological universality with regard to their dynamic behavior [ 1, 2]. As a parameter is smoothly increased, a fascinating varie...It is known that certain one parameter families of unimodal maps of the interval have a topological universality with regard to their dynamic behavior [ 1, 2]. As a parameter is smoothly increased, a fascinating variety of dynamic behaviors are produced. For some families the behaviors are monotonic in the parameter, while in others they are not [3]. The question is what sort of conditions on a one parameter family will ensure this monotonicity of the behavior with the parameter? The answer is unknown and will not be given here. What we do instead is to investigate certain geometric-dynamic-combinatorial consequences of assuming that the family has this monotonicity. Specifically, using tools of symbolic dynamics, state space is "course grained" with a finite alphabet. We decompose a non-invertible map into nonlinear but invertible pieces. From these invertible pieces, we form inverse maps via composition along words. Equations of motion are developed for both forward and inverse orbits (in both the variables of state space and the parameter), and an equation relating forward and inverse motions at fix-points is exhibited. Finally, we deduce a list of conditions, each of which is equivalent to monotone behavior. One of these conditions states that simple parity characteristics of words correspond to definite dynamics near fixed-points and vice versa.展开更多
The rational design of urban public space has more and more attention of the community; in the end, people need public spaces of an active exploration and attempt. Through human experience of urban public space, the d...The rational design of urban public space has more and more attention of the community; in the end, people need public spaces of an active exploration and attempt. Through human experience of urban public space, the design of public space in the city questioned the rationality, emphasized the human behavior activities on public space design requirements, and emphasized the place of people, human behavior activities, and the activities of the Trinity design ideas. By comparing the two public spaces Analysis of Chongqing, it further emphasized the left of human activity, human stories and spirit; public space has lost its significance.展开更多
Topological entropy can be an indicator of complicated behavior in dynamical systems. It is first introduce by Adler, Konheim and McAndrew by using open covers in 1965. After that it is still an active research by man...Topological entropy can be an indicator of complicated behavior in dynamical systems. It is first introduce by Adler, Konheim and McAndrew by using open covers in 1965. After that it is still an active research by many researchers to produce more properties and applications up to nowadays. The purpose of this paper is to review and explain most important concepts and results of topological entropies of continuous self-maps for dynamical systems on compact and non-compact topological and metric spaces. We give proofs for some of its elementary properties of the topological entropy. Slight modification on Adler's topological entropy is also presented.展开更多
Based on the time-delayed embedding method of phase space reconstruction, a new method to compute the approximate entropy (ApEn) of electroencephalogram (EEG) is proposed. The computational results show that there...Based on the time-delayed embedding method of phase space reconstruction, a new method to compute the approximate entropy (ApEn) of electroencephalogram (EEG) is proposed. The computational results show that there are signiticant differences between epileptic: EEG and normal EEG in the approximate entropy with the variance of embedding dimension. This conclusion is helpful to analyze the dynamical behavior of difibrent EEGs by entropy.展开更多
As the ultra high DC voltage grid comes into an important stage in the ‘Twelfth Five-year Plan’ of China, the requirement on the operation safety of power equipment needs to be improved. Oil-paper insulation plays a...As the ultra high DC voltage grid comes into an important stage in the ‘Twelfth Five-year Plan’ of China, the requirement on the operation safety of power equipment needs to be improved. Oil-paper insulation plays a significant role as the main insulation material of many key power equipments. The space charge behaviors of oil-paper insulation not only affect the dielectric strength, but also relate to the stability and security of power transmission facilities. Until now, the research on the space charge behaviors of oil-paper insulation remains on the stage of objective description and phenomenon explanation, thus it is very urgent to make some feature extractions on the test results in order to further investigate the DC space charge behaviors of oil-paper insulation. In this paper, based on the large numbers of test data in the first stage, data mining and feature extractions were performed on the DC space charge behavior of oil-paper insulation. The variation laws of some key characteristic parameters obtained in different experiment conditions such as the total charge injection amount, apparent charge mobility, and trap energy distribution were analyzed. In addition, the distribution of trapping level inside oil-paper was calculated by using the PEA test results based on the mechanism of the isothermal decay current, which realized the approximate calculation of trap depth by charge decay characteristics. What’s more, the exponential injection and decay equations of DC space charge changing with time were acquired for the first time, and the physical meanings of related parameters were defined. This has laid a foundation for the prediction and simulation of space charge in the oil-paper insulation.展开更多
The m-th order detrended Brownian motion is defined as the orthogonal component of projection of the standard Brownian motion onto the subspace spanned by polynomials of degree up to m. We obtain the Karhunen-Loeve ex...The m-th order detrended Brownian motion is defined as the orthogonal component of projection of the standard Brownian motion onto the subspace spanned by polynomials of degree up to m. We obtain the Karhunen-Loeve expansion for the process and establish a connection with the generalized (m-th order) Brownian bridge developed by MacNeill (1978) in the study of distributions of polynomial regression. The resulting distribution identity is also verified by a stochastic Fubini approach. As applications, large and small deviation asymptotic behaviors for the L2 norm are given.展开更多
In this paper,we consider a localized problem with free boundary for the heat equation in higher space dimensions and heterogeneous environment.For simplicity,we assume that the environment and solution are radially s...In this paper,we consider a localized problem with free boundary for the heat equation in higher space dimensions and heterogeneous environment.For simplicity,we assume that the environment and solution are radially symmetric.First,by using the contraction mapping theorem,we prove that the local solution exists and is unique.Then,some sufficient conditions are given under which the solution will blow up in finite time.Our results indicate that the blowup occurs if the initial data are sufficiently large.Finally,the long time behavior of the global solution is discussed.It is shown that the global fast solution does exist if the initial data are sufficiently small,while the global slow solution is possible if the initial data are suitably large.展开更多
The probability of long-range connection among neurons could be changeable in biological neuronal networks. In this paper, the probability of long-range connection between neurons is not fixed at a constant but varies...The probability of long-range connection among neurons could be changeable in biological neuronal networks. In this paper, the probability of long-range connection between neurons is not fixed at a constant but varies in a numerical region (≤p0 ), and then the collective behaviors of neurons are detected. A statistical factor in the two-dimensional space is used to detect the phase transition and robustness of spiral wave in the active network of neurons. It is found that the development of spatiotem-poral pattern depends on the numerical region (≤p0 ) for the probability of long-range connection. Coherence resonance-like behavior is observed due to the fluctuation in the long-range probability. Spiral waves emerge to occupy the network of neurons under an optimized probability of long-range connection, and it shows certain robustness in weak channel noise.展开更多
文摘Knowledge of the culture difference in inter-cultural communicative is of primary importance. It is so in Sino-American communication, especially in speech, one of the two means of communication through language, with the other being writing. American and Chinese, brought up in different cultures, have different speech styles. Diversity in speech styles not only involves communication through verbal speech, but also through such non-verbal acts as kinesics, proxemics, and paralinguistic elements. Here the speech styles in the two cultures, American and Chinese, are contrasted with examples from a cultural perspective.
基金*The project supported by National Natural Science Foundation of China under Grant No. 90203008 and the Doctoral Foundation of the Ministry of Education of China
文摘Based on our previously pulse-coupled integrate-and-fire neuron model in small world networks, we investigate the effects of different connectivity topologies on complex behavior of electroencephalographic-like signals produced by this model. We show that several times series analysis methods that are often used for analyzing complex behavior of electroencephalographic-like signals, such as reconstruction of the phase space, correlation dimension, fractal dimension, and the Hurst exponent within the rescaled range analysis (R/S). We lind that the different connectivity topologies lead to different dynamical behaviors in models of integrate-and-fire neurons.
基金Project(12 High-tech Urban C11) supported by High-tech Urban Development Program of Ministry of Land,Transport and Maritime Affairs,Korea
文摘The buckling behavior of single layer space structure is very sensitive. The joint rigidity, moreover, is one of the main factors of stability which may determine the entire failure behavior. Thus, the reasonable stiffness of joint system, which is neither total pin assumption nor perfect fix condition, is very important to apply to the real single layer space one. Therefore, the purpose of this work was to investigate the buckling behavior of single layer space structure, using the development of the upgraded stiffness matrix for the joint rigidity. To derive tangential stiffness matrix, a displacement function was assumed using translational and rotational displacement at the node. The geometrical nonlinear analysis was simulated not only with perfect model but also with imperfect one. As a result, the one and two free nodal numerical models were investigated using derived stiffness matrix. It was figured out that the buckling load increases in proportion to joint rigidity with rise-span ratio. The stability of numerical model is very sensitive with the initial imperfection, responding of bifurcation in the structure.
基金supported by the National Science Foundation of China (Nos. 51105131 and 51475143)the Henan Provincial Key Scientific and Technological Project (No. 142102210110)the Tianjin Science and Technology Support Program
文摘The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating conditions of space bearings. A traction coefficient calculation model was presented. The rheological property and rheological parameters of the lubricant at a low oil inlet temperature were analyzed based on the Tevaarwerk-Johnson model. The results showed that the lubricating oil No. 4116 was sensitive to the rolling speed and had lower sensitivity to the normal load. This lubricating oil is more suitable for applications under high speed when it is used below 0 ℃. It behaves as an elastic-plastic fluid operating below 0 ℃. Both the average limiting shear stress and the average elastic shear modulus have a negative correlation with the rolling speed and oil inlet temperature and have a positive correlation with the normal load.
文摘The paper takes the relation between soundscapes and power struggles as its problem area and focuses on the role of music that is performed in public protests. It argues that music and street performances are conceived and therefore utilised as sonic acts of political struggle in urban realm. Starting with a general understanding of hearing mechanisms, the study elucidates the relationships among territoriality of soundscape, identity construction, social segregation and polarisation, and finally, power struggle. Within the framework of the intersection area of these concepts, the paper discusses the processes of politisation of soundscape through music as a form of protest event that is performed in public realm. Throughout the paper, it is focused on the significant cases of public protests as well as political events that occured in public space. The main emphasis is on the use of sound technologies to impose power on masses of people. The paper tackles the question of how the salient characteristics of soundscape are sonically adopted as means for counter-political acts in public realm.
文摘 The effect of Batroxobin on spatial memory disorder of left temporal ischemic rats and the expression of HSP32 and HSP70 were investigated with Morri`s water maze and immunohistochemistry methods. The results showed that the mean reaction time and distance of temporal ischemic rats in searching a goal were significantly longer than those of the sham-operated rats and at the same time HSP32 and HSP70 expression of left temporal ischemic region in rats was significantly increased as compared with the sham-operated rats. However, the mean reaction time and distance of the Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of HSP32 and HSP70 immune reactive cells of Batroxobin-treated rats was also less than that of the ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats; and the down-regulation of the expression of HSP32 and HSP70 is probably related to the attenuation of ischemic injury.
文摘Traditionally, microclimate, behavior and space design are characterized by a separation among climatologists, behavior researchers and designers. It is also unrealizable to apply the research results to the space design because of the gap created by the interdisciplinarity. In addition, although the relationships among space form, urban microclimate and people are intuitively understood, there are still not reasonable predictions on how a space affects the microclimate, and how the microclimate and space will affect people's sensation and behavior. By recording the microclimate and people's responses, this paper discusses the relationship between people's sensation and microclimate as well as people's behavior and open space in a busy downtown pedestrian street during hot summer. The research finds that shade plays a crucial role in outdoor comfort. All of the other objectively comfortable and acceptable microclimates differ significantly different shade situation. Simultaneously, space contradiction can be considered an essential factor for spatial utilization. This paper also provides proposal on canyon open space design based on this case study.
文摘The novel Ragtime, written by the contemporary American writer Edgar Lawrence Doctorow, imaginatively reconstructs the urban space in the Progressive Era. In the period of social transformation and change, all kinds of contradictions in New York City are becoming increasingly acute. The division of space reflects the power discourse of different classes, races, and genders. The connection, extension and expansion of space promote the features of urban modernity and open up new patterns of social behavior and opportunities for survival, but cannot fundamentally alleviate the capitalist crisis. Spatial layout and distribution of the city are not only the reflection of social relations, but also the "time capsule", bearing the history of the city, and the writing of space offers a mirror for the author's emotion and value judgment.
文摘This paper addresses new trends in quantitative geography research. Modern social science research--including economic and social geography--has in the past decades shown an increasing interest in micro-oriented behaviour of actors. This is inter alia clearly reflected in SIMs (spatial interaction models), where discrete choice approaches have assumed a powerful position. This paper aims to provide in particular a concise review of micro-based research, with the aim to review the potential--but also the caveats---of micro models to map out human behaviour. In particular, attention will be devoted to interactive learning principles that shape individual decisions. Lessons from cognitive sciences will be put forward and illustrated, amongst others on the basis of computational neural networks or spatial econometric approaches. Particular attention will be paid to non-linear dynamic spatial models, amongst others, in the context of chaos theory and complexity science. The methodology of deductive reasoning under conditions of large data bases in studying human mobility will be questioned as well. In this context more extensive attention is given to ceteris paribus conditions and evolutionary thinking. The relevance of the paper will be illustrated by referring to various spatial applications in different disciplines and different application areas, e.g. in geography, regional science or urban economics.
基金Foundation item: Projects(50571059, 50615024 ) supported by the National Natural Science Foundation of ChinaProject(NCET-07-0536) supported by Program for New Century Excellent Talents in UniversityProject(IRT0739) supported by Program for Innovative Research Team in University
文摘Deep level donor's ionization behavior of passive film formed on the surface of stainless steel was investigated by Mott-Schottky plots. It is indicated that transformation process of deep level donors' ionization behavior of passive film on surface of stainless steel can be divided into 4 stages with rising immersion time. At the initial immersion stage (10 min), Fe(II) located in the octahedral sites of the unit cell is not ionized and the deep level does not appear in Mott-Schottky plots. At the second stage (9-38 h), Fe(II) located in the octahedral sites starts to be ionized, which results in deep level donors' generation and density of deep level donors almost is constant with augmenting immersion time but the thickness of space charge layer is more and more thicker with rising immersion time. At the third stage (48 h-12 d), density of deep level donors rises with increasing immersion time and the thickness of passive films space charge layer decreases. At last stage (above 23 d), both the space charge layer's thickness and density of deep level donors are no longer changed with increasing immersion time. In the overall immersion stage, the shallow level donors' density is invariable all the time. The mechanism of deep level donor's ionization can be the generation of metal vacancies, which results in crystal lattice's aberration and the aberration energy urges the ionization of Fe( II ) in octahedral sites.
文摘The end windings of generators are excited to vibrations due to electromagnetic forces which can cause severe damage (especially in case of resonance) and noise. To avoid this, it is important to predict the natural frequencies and modes of the end windings with finite elements during the design process. Hence, a material model of the complete stator bar is necessary. This paper shows the development of such a material model. The composite structure of a stator bar is quite complex and makes it impossible to provide a quick calculation of the eigenvalues. That is the reason for using a suitable, homogeneously, geometry based solid model. Special attention was paid to the experimental determination of the material characteristics of the orthotropic composite space brackets. The numerical results have been evaluated against measurements. Eigenvalues, Young's modulus, and shear modulus have been experimentally investigated.
文摘It is known that certain one parameter families of unimodal maps of the interval have a topological universality with regard to their dynamic behavior [ 1, 2]. As a parameter is smoothly increased, a fascinating variety of dynamic behaviors are produced. For some families the behaviors are monotonic in the parameter, while in others they are not [3]. The question is what sort of conditions on a one parameter family will ensure this monotonicity of the behavior with the parameter? The answer is unknown and will not be given here. What we do instead is to investigate certain geometric-dynamic-combinatorial consequences of assuming that the family has this monotonicity. Specifically, using tools of symbolic dynamics, state space is "course grained" with a finite alphabet. We decompose a non-invertible map into nonlinear but invertible pieces. From these invertible pieces, we form inverse maps via composition along words. Equations of motion are developed for both forward and inverse orbits (in both the variables of state space and the parameter), and an equation relating forward and inverse motions at fix-points is exhibited. Finally, we deduce a list of conditions, each of which is equivalent to monotone behavior. One of these conditions states that simple parity characteristics of words correspond to definite dynamics near fixed-points and vice versa.
文摘The rational design of urban public space has more and more attention of the community; in the end, people need public spaces of an active exploration and attempt. Through human experience of urban public space, the design of public space in the city questioned the rationality, emphasized the human behavior activities on public space design requirements, and emphasized the place of people, human behavior activities, and the activities of the Trinity design ideas. By comparing the two public spaces Analysis of Chongqing, it further emphasized the left of human activity, human stories and spirit; public space has lost its significance.
文摘Topological entropy can be an indicator of complicated behavior in dynamical systems. It is first introduce by Adler, Konheim and McAndrew by using open covers in 1965. After that it is still an active research by many researchers to produce more properties and applications up to nowadays. The purpose of this paper is to review and explain most important concepts and results of topological entropies of continuous self-maps for dynamical systems on compact and non-compact topological and metric spaces. We give proofs for some of its elementary properties of the topological entropy. Slight modification on Adler's topological entropy is also presented.
基金Natural Science Foundation of Fujian Province of China grant number: 2010J01210 and T0750008
文摘Based on the time-delayed embedding method of phase space reconstruction, a new method to compute the approximate entropy (ApEn) of electroencephalogram (EEG) is proposed. The computational results show that there are signiticant differences between epileptic: EEG and normal EEG in the approximate entropy with the variance of embedding dimension. This conclusion is helpful to analyze the dynamical behavior of difibrent EEGs by entropy.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2009CB724505-1)the Doctor Foundation of Southwest University (Grant No. SWU110038)the Fundamental Research Funds for the Central Universities of Southwest University (Grant No. XDJK2010C020)
文摘As the ultra high DC voltage grid comes into an important stage in the ‘Twelfth Five-year Plan’ of China, the requirement on the operation safety of power equipment needs to be improved. Oil-paper insulation plays a significant role as the main insulation material of many key power equipments. The space charge behaviors of oil-paper insulation not only affect the dielectric strength, but also relate to the stability and security of power transmission facilities. Until now, the research on the space charge behaviors of oil-paper insulation remains on the stage of objective description and phenomenon explanation, thus it is very urgent to make some feature extractions on the test results in order to further investigate the DC space charge behaviors of oil-paper insulation. In this paper, based on the large numbers of test data in the first stage, data mining and feature extractions were performed on the DC space charge behavior of oil-paper insulation. The variation laws of some key characteristic parameters obtained in different experiment conditions such as the total charge injection amount, apparent charge mobility, and trap energy distribution were analyzed. In addition, the distribution of trapping level inside oil-paper was calculated by using the PEA test results based on the mechanism of the isothermal decay current, which realized the approximate calculation of trap depth by charge decay characteristics. What’s more, the exponential injection and decay equations of DC space charge changing with time were acquired for the first time, and the physical meanings of related parameters were defined. This has laid a foundation for the prediction and simulation of space charge in the oil-paper insulation.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.DL13BBX10)
文摘The m-th order detrended Brownian motion is defined as the orthogonal component of projection of the standard Brownian motion onto the subspace spanned by polynomials of degree up to m. We obtain the Karhunen-Loeve expansion for the process and establish a connection with the generalized (m-th order) Brownian bridge developed by MacNeill (1978) in the study of distributions of polynomial regression. The resulting distribution identity is also verified by a stochastic Fubini approach. As applications, large and small deviation asymptotic behaviors for the L2 norm are given.
基金supported by National Natural Science Foundation of China (Grant Nos.11071209 and 10801115)the PhD Programs Foundation of Ministry of Education of China (Grant No.20113250110005)
文摘In this paper,we consider a localized problem with free boundary for the heat equation in higher space dimensions and heterogeneous environment.For simplicity,we assume that the environment and solution are radially symmetric.First,by using the contraction mapping theorem,we prove that the local solution exists and is unique.Then,some sufficient conditions are given under which the solution will blow up in finite time.Our results indicate that the blowup occurs if the initial data are sufficiently large.Finally,the long time behavior of the global solution is discussed.It is shown that the global fast solution does exist if the initial data are sufficiently small,while the global slow solution is possible if the initial data are suitably large.
基金supported by the National Nature Science Foundation of China (Grant Nos.11265008 and 10972179)
文摘The probability of long-range connection among neurons could be changeable in biological neuronal networks. In this paper, the probability of long-range connection between neurons is not fixed at a constant but varies in a numerical region (≤p0 ), and then the collective behaviors of neurons are detected. A statistical factor in the two-dimensional space is used to detect the phase transition and robustness of spiral wave in the active network of neurons. It is found that the development of spatiotem-poral pattern depends on the numerical region (≤p0 ) for the probability of long-range connection. Coherence resonance-like behavior is observed due to the fluctuation in the long-range probability. Spiral waves emerge to occupy the network of neurons under an optimized probability of long-range connection, and it shows certain robustness in weak channel noise.