In this paper, Henri Lefebvre's theorizations about representational space and representations of space will be employed to examine Hart Crane's imagination of them in The Bridge. First, according to Lefebvre, repre...In this paper, Henri Lefebvre's theorizations about representational space and representations of space will be employed to examine Hart Crane's imagination of them in The Bridge. First, according to Lefebvre, representations of space are created with violence for the purpose of accumulating capital. On the other hand, representational space is directly lived or affectively felt, opened up by inhabitants' imagination. In addition, Lefebvre points out that in abstract space, representational space will be invaded by representations of space. In The Bridge, Crane's affective experience with the Brooklyn Bridge or the subway indicates that he treats New York as a representational space. Besides, Crane expresses his concern for how capitalism has encroached on it. It would seem that Crane has followed Lefebvre's line of thinking in The Bridge. However, it is actually a specious analysis because both the Brooklyn Bridge and the subway are representations of space. And in this long poem, Crane feels the urban space through history, which plays a key role in creating representations of space. Thus, we can conclude that Crane is actually taking "a walk in between" in The Bridge. With his imagination, Crane has combined representations of space and representational space into his own poetic vision.展开更多
The spin-one Duffin-Kemmer-Petiau (DKP) oscillator under a magnetic field in the presence of Ihe minimal length in the noncommutative coordinate space is studied by using the momentum space representation. The expli...The spin-one Duffin-Kemmer-Petiau (DKP) oscillator under a magnetic field in the presence of Ihe minimal length in the noncommutative coordinate space is studied by using the momentum space representation. The explicit form of energy eigenvalues is found, and the eigenfunctions are obtained in terms of the Jacobi polynomials. It shows that for the same azimuthal quantum number, the energy E increases monotonically with respect to the noncomnmtative parameter and the minimal length parameter. Additionally, we also report some special cases aiming to discuss the effect of the noncommutative coordinate space and the minimal length in the energy spectrum.展开更多
The goal of ecopsychology is to awaken the inherent sense of environmental reciprocity that lies within the ecological unconsciousness. Proclaiming the spirit of ecopsychology, Theodore Roszak argues that psychotherap...The goal of ecopsychology is to awaken the inherent sense of environmental reciprocity that lies within the ecological unconsciousness. Proclaiming the spirit of ecopsychology, Theodore Roszak argues that psychotherapy is an urban movement, but human beings can never heal themselves until they reconnect with nature. Other therapies aim at healing the alienation between person and person, person and family, person and society; ecopsychology intends to heal the more primary alienation between the person and the natural environment. Henri Lefebvre's work has revitalized urban studies, geography and planning via concepts like the social production of space. Lefebvre claims that space is not an inert, neutral, and pre-existing given, but rather, an on-going production of spatial relations. According to Lefebvre, space is produced by three types of practice: spatial practices of physical transformation of the environment, practices of representation of space, and everyday practices of representational space. Lefebvre further presents a "differential space," named as such for its dialectical resistance to the forces of homogenization present in "abstract space." The aim of this paper is to trace the ecological voice from Roszak's The Voice of the Earth in Henri Lefebvre's "differential space." Roszak's ecopsychology has formed a differential space, acknowledging that the boundaries of dualism and separations such as mind and body, man and nature should be finally dissolved in terms of ecological sustainability. Within this space, a holistic approach and thinking are created and required to take into account perception of the inextricable relationship between all life and all phenomena.展开更多
The external stability of fractional-order continuous linear control systems described by both fractional-order state space representation and fractional-order transfer function is mainly investigated in this paper. I...The external stability of fractional-order continuous linear control systems described by both fractional-order state space representation and fractional-order transfer function is mainly investigated in this paper. In terms of Lyapunov’s stability theory and the stability analysis of the integer-order linear control systems, the definitions of external stability for fractional-order control systems are presented. By using the theorems of the Mittag-Leffler function in two parameters, the necessary and sufficient conditions of external stability are directly derived. The illustrative examples and simulation results are also given.展开更多
Horizontal wind measured by wind profiling radar(WPR) is based on uniform wind assumption in volume of lateral beam. However, this assumption cannot completely meet in the real atmosphere. The subject of this work is ...Horizontal wind measured by wind profiling radar(WPR) is based on uniform wind assumption in volume of lateral beam. However, this assumption cannot completely meet in the real atmosphere. The subject of this work is to analyze the influence of atmospheric inhomogeneities for wind measurement. Five-beam WPR can measure two groups of horizontal wind components U and V independently, using the difference of horizontal wind components U and V can evaluate the influence of the inhomogeneity of the atmospheric motion on wind measurement. The influences can be divided into both inhomogeneous distribution of horizontal motion and vertical motion. Based on wind measurements and meteorological background information, a new means of coordinate rotation the two kinds of inhomogeneous factor was separated, and the impact in different weather background was discussed. From analysis of the wind measured by type of PB-II WPR(445MHz) during 2012 at Yanqing of Beijing, it is shown that the inhomogeneity of horizontal motion is nearly the same in U and V direction. Both the inhomogeneities of horizontal motion and vertical motion have influence on wind measurement, and the degrees of both influences are associated with changes of wind speed. In clear air, inhomogeneity of horizontal motion is the main influence on wind measurement because of small vertical velocity.In precipitation, the two influences are larger than that in clear air.展开更多
Assume that B is a separable real Banach space and X(t) is a diffusion process on B. In thispaper, we will establish the representation theorem of martingale additive functionals of X(t).
Let B be a separable real Banach space and X(t) be a symmetric conservative diffusionprocess taking values in B. In this paper, we decompose the functional u(X(t),t) into a sumof a square integrable martingale and a r...Let B be a separable real Banach space and X(t) be a symmetric conservative diffusionprocess taking values in B. In this paper, we decompose the functional u(X(t),t) into a sumof a square integrable martingale and a regular 0-quadratic variation process. On this basis, weestablish the predictable representation theorem of X(t).展开更多
This paper presents a new and simple scheme to describe the convex hull in R^d,which only uses three kinds of the faces of the convex hull,i.e.,the d-1-faces,d-2-faces and 0-faces.Thus,we develop an efficient new algo...This paper presents a new and simple scheme to describe the convex hull in R^d,which only uses three kinds of the faces of the convex hull,i.e.,the d-1-faces,d-2-faces and 0-faces.Thus,we develop an efficient new algorithm for constructing the convex hull of a finite set of points incrementally. This algorithm employs much less storage and time than that of the previously-existing approaches.The analysis of the running time as well as the storage for the new algorithm is also theoretically made.The algorithm is optimal in the worst case for even d.展开更多
We present a twisted version of the Alexander polynomial associated with a matrix rep- resentation of the knot group.Examples of two knots with the same Alexander module but different twisted Alexander polynomials are...We present a twisted version of the Alexander polynomial associated with a matrix rep- resentation of the knot group.Examples of two knots with the same Alexander module but different twisted Alexander polynomials are given.展开更多
The concept of a consistent approximation representation space is introduced. Many types of information systems can be treated and unified as consistent approximation representation spaces. At the same time, under the...The concept of a consistent approximation representation space is introduced. Many types of information systems can be treated and unified as consistent approximation representation spaces. At the same time, under the framework of this space, the judgment theorem for determining consistent attribute set is established, from which we can obtain the approach to attribute reductions in information systems. Also, the characterizations of three important types of attribute sets (the core attribute set, the relative necessary attribute set and the unnecessary attribute set) are examined.展开更多
Real-Time Precise Point Positioning(RT-PPP)has been one of the research hotspots in GNSS(Global Navigation Satellite System)community for decades.Real-time precise products of satellite orbits and clocks are the prere...Real-Time Precise Point Positioning(RT-PPP)has been one of the research hotspots in GNSS(Global Navigation Satellite System)community for decades.Real-time precise products of satellite orbits and clocks are the prerequisite for RT-PPP.Thus,it is of great importance to investigate the current multi-GNSS real-time precise products in State Space Representation(SSR)from diferent analysis centers.In this article,SSR products from 10 analysis centers are comprehensively evaluated by comparing them with the fnal products and performing the kinematic PPP.The results show that analysis centers CNES(Centre National D’Etudes Spatiales)and WHU(GNSS Research Center of Wuhan University)provide the most complete products with the best quality.Concerning the accuracy of real-time products for the GNSSs,the accuracies of orbit and clock products are better than 5 cm and 0.15 ns,respectively,for Global Positioning System(GPS),followed by Galileo navigation satellite system(Galileo),BeiDou-3 Navigation Satellite System(BDS-3),GLObal NAvigation Satellite System(GLONASS),and BeiDou-2 Navigation Satellite System(BDS-2).Meanwhile,the results of the RT-PPP with quad-system show that the positioning accuracies are 1.76,1.12 and 2.68 cm in east,north,and up directions,respectively,and the convergence time to 0.1,0.1,0.2 m for corresponding directions is 15.35 min.展开更多
This paper studies the state/output synchronization of switched Boolean networks (SBNs) with impulsive effects via the algebraic state space representation (ASSR) approach. First, an algebraic form is established ...This paper studies the state/output synchronization of switched Boolean networks (SBNs) with impulsive effects via the algebraic state space representation (ASSR) approach. First, an algebraic form is established for SBNs with impulsive effects via ASSR. Second, based on the algebraic form, some necessary and sufficient conditions are presented for the state/output synchronization of SBNs with impulsive effects under arbitrary switching signals. Third, two special kinds of switching signals, that is, free switching signal and feedback switching signal, are considered for the state synchroniza-tion of SBNs with impulsive effects. Finally, two illustrative examples are worked out to show the effectiveness of the obtained results.展开更多
Satellite Based Augmentation System(SBAS)is one of the services provided by the BeiDou Navigation Satellite System(BDS).It broadcasts four types of diferential corrections to improve user application performance.These...Satellite Based Augmentation System(SBAS)is one of the services provided by the BeiDou Navigation Satellite System(BDS).It broadcasts four types of diferential corrections to improve user application performance.These corrections include the State Space Representation(SSR)based satellite orbit/clock corrections and ionospheric grid corrections,and the Observation Space Representation(OSR)based partition comprehensive corrections.The algorithms generating these SBAS corrections are not introduced in previous researches,and the user SBAS positioning performance with the contribution of BDS-3 has not been evaluated.In this paper,we present the BDS SBAS algorithms for these diferential corrections in detail.Four types of Precise Point Positioning(PPP)function models for BDS Dual-Frequency(DF)and Single-Frequency(SF)users using the OSR and SSR parameters are also proposed.One week of data in 2020 is collected at 20 reference stations including the observations of both BeiDou-2 Navigation Satellite System(BDS-2)and BeiDou-3 Navigation Satellite System(BDS-3)satellites,and the PPP under various scenarios are performed using all the datasets and the BDS SBAS broadcast corrections.The results show that the performance of BDS-2/BDS-3 combination is superior to that of BDS-2 only constellation.The positioning errors in Root Mean Square(RMS)for the static DF PPP are better than 8 cm/15 cm in horizontal/vertical directions,while for the static SF PPP are 11 cm/24 cm.In the scenarios of simulated kinematic PPP,three Dimension(3D)positioning errors can reach 0.5 m in less than 10 min for the DF PPP and 30 min for the SF PPP,and the RMSs of the DF and SF PPP are better than 17 cm/21 cm and 20 cm/32 cm in horizontal/vertical directions.In a real-time single-and dual-frequency kinematic positioning test,the positioning errors of all three components can reach 0.5 m within 30 min,and the positioning accuracy after solution convergence in the N,E and U directions is better than 0.3 m.展开更多
Image-based breast tumor classification is an active and challenging problem.In this paper,a robust breast tumor classification framework is presented based on deep feature representation learning and exploiting avail...Image-based breast tumor classification is an active and challenging problem.In this paper,a robust breast tumor classification framework is presented based on deep feature representation learning and exploiting available information in existing samples.Feature representation learning of mammograms is fulfilled by a modified nonnegative matrix factorization model called LPML-LRNMF,which is motivated by hierarchical learning and layer-wise pre-training(LP)strategy in deep learning.Low-rank(LR)constraint is integrated into the feature representation learning model by considering the intrinsic characteristics of mammograms.Moreover,the proposed LPML-LRNMF model is optimized via alternating direction method of multipliers and the corresponding convergence is analyzed.For completing classification,an inverse projection sparse representation model is introduced to exploit information embedded in existing samples,especially in test ones.Experiments on the public dataset and actual clinical dataset show that the classification accuracy,specificity and sensitivity achieve the clinical acceptance level.展开更多
文摘In this paper, Henri Lefebvre's theorizations about representational space and representations of space will be employed to examine Hart Crane's imagination of them in The Bridge. First, according to Lefebvre, representations of space are created with violence for the purpose of accumulating capital. On the other hand, representational space is directly lived or affectively felt, opened up by inhabitants' imagination. In addition, Lefebvre points out that in abstract space, representational space will be invaded by representations of space. In The Bridge, Crane's affective experience with the Brooklyn Bridge or the subway indicates that he treats New York as a representational space. Besides, Crane expresses his concern for how capitalism has encroached on it. It would seem that Crane has followed Lefebvre's line of thinking in The Bridge. However, it is actually a specious analysis because both the Brooklyn Bridge and the subway are representations of space. And in this long poem, Crane feels the urban space through history, which plays a key role in creating representations of space. Thus, we can conclude that Crane is actually taking "a walk in between" in The Bridge. With his imagination, Crane has combined representations of space and representational space into his own poetic vision.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11465006 and 11565009)the Project of Research Foundation for Graduate Students in Guizhou Province,China(Grant No.(2017)11108)
文摘The spin-one Duffin-Kemmer-Petiau (DKP) oscillator under a magnetic field in the presence of Ihe minimal length in the noncommutative coordinate space is studied by using the momentum space representation. The explicit form of energy eigenvalues is found, and the eigenfunctions are obtained in terms of the Jacobi polynomials. It shows that for the same azimuthal quantum number, the energy E increases monotonically with respect to the noncomnmtative parameter and the minimal length parameter. Additionally, we also report some special cases aiming to discuss the effect of the noncommutative coordinate space and the minimal length in the energy spectrum.
文摘The goal of ecopsychology is to awaken the inherent sense of environmental reciprocity that lies within the ecological unconsciousness. Proclaiming the spirit of ecopsychology, Theodore Roszak argues that psychotherapy is an urban movement, but human beings can never heal themselves until they reconnect with nature. Other therapies aim at healing the alienation between person and person, person and family, person and society; ecopsychology intends to heal the more primary alienation between the person and the natural environment. Henri Lefebvre's work has revitalized urban studies, geography and planning via concepts like the social production of space. Lefebvre claims that space is not an inert, neutral, and pre-existing given, but rather, an on-going production of spatial relations. According to Lefebvre, space is produced by three types of practice: spatial practices of physical transformation of the environment, practices of representation of space, and everyday practices of representational space. Lefebvre further presents a "differential space," named as such for its dialectical resistance to the forces of homogenization present in "abstract space." The aim of this paper is to trace the ecological voice from Roszak's The Voice of the Earth in Henri Lefebvre's "differential space." Roszak's ecopsychology has formed a differential space, acknowledging that the boundaries of dualism and separations such as mind and body, man and nature should be finally dissolved in terms of ecological sustainability. Within this space, a holistic approach and thinking are created and required to take into account perception of the inextricable relationship between all life and all phenomena.
文摘The external stability of fractional-order continuous linear control systems described by both fractional-order state space representation and fractional-order transfer function is mainly investigated in this paper. In terms of Lyapunov’s stability theory and the stability analysis of the integer-order linear control systems, the definitions of external stability for fractional-order control systems are presented. By using the theorems of the Mittag-Leffler function in two parameters, the necessary and sufficient conditions of external stability are directly derived. The illustrative examples and simulation results are also given.
基金National Natural Science Foundation of China(41475029)China Meteorological Administration Special Public Welfare Research Fund(GYHY201306004)Meteorological Key Technology Integration and Application of the China Meteorological Administration(CMAGJ2013M74)
文摘Horizontal wind measured by wind profiling radar(WPR) is based on uniform wind assumption in volume of lateral beam. However, this assumption cannot completely meet in the real atmosphere. The subject of this work is to analyze the influence of atmospheric inhomogeneities for wind measurement. Five-beam WPR can measure two groups of horizontal wind components U and V independently, using the difference of horizontal wind components U and V can evaluate the influence of the inhomogeneity of the atmospheric motion on wind measurement. The influences can be divided into both inhomogeneous distribution of horizontal motion and vertical motion. Based on wind measurements and meteorological background information, a new means of coordinate rotation the two kinds of inhomogeneous factor was separated, and the impact in different weather background was discussed. From analysis of the wind measured by type of PB-II WPR(445MHz) during 2012 at Yanqing of Beijing, it is shown that the inhomogeneity of horizontal motion is nearly the same in U and V direction. Both the inhomogeneities of horizontal motion and vertical motion have influence on wind measurement, and the degrees of both influences are associated with changes of wind speed. In clear air, inhomogeneity of horizontal motion is the main influence on wind measurement because of small vertical velocity.In precipitation, the two influences are larger than that in clear air.
文摘Assume that B is a separable real Banach space and X(t) is a diffusion process on B. In thispaper, we will establish the representation theorem of martingale additive functionals of X(t).
基金This project is supported by the National Natural Science Foundation of China
文摘Let B be a separable real Banach space and X(t) be a symmetric conservative diffusionprocess taking values in B. In this paper, we decompose the functional u(X(t),t) into a sumof a square integrable martingale and a regular 0-quadratic variation process. On this basis, weestablish the predictable representation theorem of X(t).
基金This work is supported by the National Natural Science Foundation of China.
文摘This paper presents a new and simple scheme to describe the convex hull in R^d,which only uses three kinds of the faces of the convex hull,i.e.,the d-1-faces,d-2-faces and 0-faces.Thus,we develop an efficient new algorithm for constructing the convex hull of a finite set of points incrementally. This algorithm employs much less storage and time than that of the previously-existing approaches.The analysis of the running time as well as the storage for the new algorithm is also theoretically made.The algorithm is optimal in the worst case for even d.
文摘We present a twisted version of the Alexander polynomial associated with a matrix rep- resentation of the knot group.Examples of two knots with the same Alexander module but different twisted Alexander polynomials are given.
基金Major State Basic Research Development Program of China (973 Program) (Grant No. 2002CB312200)the National Natu-ral Science Foundation of China (Grant Nos. 60673096 and 60373078)
文摘The concept of a consistent approximation representation space is introduced. Many types of information systems can be treated and unified as consistent approximation representation spaces. At the same time, under the framework of this space, the judgment theorem for determining consistent attribute set is established, from which we can obtain the approach to attribute reductions in information systems. Also, the characterizations of three important types of attribute sets (the core attribute set, the relative necessary attribute set and the unnecessary attribute set) are examined.
基金supported by the National Natural Science Funds of China(41874030,42074026,42104013)Natural Science Fund of Shanghai(21ZR1465600)+3 种基金the Program of Shanghai Academic Research Leader(20XD1423800)the Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-07-E00095)the“Shuguang Program”supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(20SG18)the Scientifc and Technological Innovation Plan from Shanghai Science and Technology Committee(20511103302,20511103402 and 20511103702).
文摘Real-Time Precise Point Positioning(RT-PPP)has been one of the research hotspots in GNSS(Global Navigation Satellite System)community for decades.Real-time precise products of satellite orbits and clocks are the prerequisite for RT-PPP.Thus,it is of great importance to investigate the current multi-GNSS real-time precise products in State Space Representation(SSR)from diferent analysis centers.In this article,SSR products from 10 analysis centers are comprehensively evaluated by comparing them with the fnal products and performing the kinematic PPP.The results show that analysis centers CNES(Centre National D’Etudes Spatiales)and WHU(GNSS Research Center of Wuhan University)provide the most complete products with the best quality.Concerning the accuracy of real-time products for the GNSSs,the accuracies of orbit and clock products are better than 5 cm and 0.15 ns,respectively,for Global Positioning System(GPS),followed by Galileo navigation satellite system(Galileo),BeiDou-3 Navigation Satellite System(BDS-3),GLObal NAvigation Satellite System(GLONASS),and BeiDou-2 Navigation Satellite System(BDS-2).Meanwhile,the results of the RT-PPP with quad-system show that the positioning accuracies are 1.76,1.12 and 2.68 cm in east,north,and up directions,respectively,and the convergence time to 0.1,0.1,0.2 m for corresponding directions is 15.35 min.
基金The research was supported by the National Natural Science Foundation of China under grant 61503225, the Natural Science Fund for Distinguished Young Scholars of Shandong Province under grant JQ201613, and the Natural Science Foundation of Shandong Province under grant ZR2015FQ003.
文摘This paper studies the state/output synchronization of switched Boolean networks (SBNs) with impulsive effects via the algebraic state space representation (ASSR) approach. First, an algebraic form is established for SBNs with impulsive effects via ASSR. Second, based on the algebraic form, some necessary and sufficient conditions are presented for the state/output synchronization of SBNs with impulsive effects under arbitrary switching signals. Third, two special kinds of switching signals, that is, free switching signal and feedback switching signal, are considered for the state synchroniza-tion of SBNs with impulsive effects. Finally, two illustrative examples are worked out to show the effectiveness of the obtained results.
基金supported by the Program of Shanghai Academic/Technology Research LeaderNational Natural Science Foundation of China(No.11673050)+2 种基金the Key Program of Special Development funds of Zhangjiang National Innovation Demonstration Zone(Grant No.ZJ2018-ZD-009)National Key R&D Program of China(No.2018YFB0504300)the Key R&D Program of Guangdong province(No.2018B030325001).
文摘Satellite Based Augmentation System(SBAS)is one of the services provided by the BeiDou Navigation Satellite System(BDS).It broadcasts four types of diferential corrections to improve user application performance.These corrections include the State Space Representation(SSR)based satellite orbit/clock corrections and ionospheric grid corrections,and the Observation Space Representation(OSR)based partition comprehensive corrections.The algorithms generating these SBAS corrections are not introduced in previous researches,and the user SBAS positioning performance with the contribution of BDS-3 has not been evaluated.In this paper,we present the BDS SBAS algorithms for these diferential corrections in detail.Four types of Precise Point Positioning(PPP)function models for BDS Dual-Frequency(DF)and Single-Frequency(SF)users using the OSR and SSR parameters are also proposed.One week of data in 2020 is collected at 20 reference stations including the observations of both BeiDou-2 Navigation Satellite System(BDS-2)and BeiDou-3 Navigation Satellite System(BDS-3)satellites,and the PPP under various scenarios are performed using all the datasets and the BDS SBAS broadcast corrections.The results show that the performance of BDS-2/BDS-3 combination is superior to that of BDS-2 only constellation.The positioning errors in Root Mean Square(RMS)for the static DF PPP are better than 8 cm/15 cm in horizontal/vertical directions,while for the static SF PPP are 11 cm/24 cm.In the scenarios of simulated kinematic PPP,three Dimension(3D)positioning errors can reach 0.5 m in less than 10 min for the DF PPP and 30 min for the SF PPP,and the RMSs of the DF and SF PPP are better than 17 cm/21 cm and 20 cm/32 cm in horizontal/vertical directions.In a real-time single-and dual-frequency kinematic positioning test,the positioning errors of all three components can reach 0.5 m within 30 min,and the positioning accuracy after solution convergence in the N,E and U directions is better than 0.3 m.
基金This work was supported in part by the National Natural Science Foundation of China(No.11701144)National Science Foundation of US(No.DMS1719932)+1 种基金Natural Science Foundation of Henan Province(No.162300410061)Project of Emerging Interdisciplinary(No.xxjc20170003).
文摘Image-based breast tumor classification is an active and challenging problem.In this paper,a robust breast tumor classification framework is presented based on deep feature representation learning and exploiting available information in existing samples.Feature representation learning of mammograms is fulfilled by a modified nonnegative matrix factorization model called LPML-LRNMF,which is motivated by hierarchical learning and layer-wise pre-training(LP)strategy in deep learning.Low-rank(LR)constraint is integrated into the feature representation learning model by considering the intrinsic characteristics of mammograms.Moreover,the proposed LPML-LRNMF model is optimized via alternating direction method of multipliers and the corresponding convergence is analyzed.For completing classification,an inverse projection sparse representation model is introduced to exploit information embedded in existing samples,especially in test ones.Experiments on the public dataset and actual clinical dataset show that the classification accuracy,specificity and sensitivity achieve the clinical acceptance level.