A numerical model for steady state analysis and analytical expressions for the AM and FM modulation responses of DFB lasers are presented.The small signal modulation responses of 3 phase shift(PS) DFB is investigate...A numerical model for steady state analysis and analytical expressions for the AM and FM modulation responses of DFB lasers are presented.The small signal modulation responses of 3 phase shift(PS) DFB is investigated for the first time.A new method(Vector Newton method) to obtain multiple longitudinal mode of DFB lasers is used.It is demonstrated that this method is suitable for obtaining multiple solution of high nonlinear equations.Longitudinal photon density distribution and multiple longitudinal mode of 3PS DFB and simple DFB lasers are analyzed.The results show that modulation response characteristics of 3PS DFB laser is as good as that of DFB,and PS can weaken the longitudinal spatial hole burning (LHSB) effect and is in favor of single longitudinal mode operating of lasers.展开更多
In this paper, using the theory of L _fuzzy topological vector spaces [1]-[6] , we study some properties of L _fuzzy inductive topologies determined by a family of L _fuzzy linerar order_homomorphisms...In this paper, using the theory of L _fuzzy topological vector spaces [1]-[6] , we study some properties of L _fuzzy inductive topologies determined by a family of L _fuzzy linerar order_homomorphisms [2] of L _ftvs, and give a characterization of inductive topologies determined by a single FLOH. As an application of this results, we prove that the quotient space of L _ftvs is also L _ftvs.展开更多
This paper proposes a novel approach to comment spam identification based on content analysis. Three main features including the number of links, content repetitiveness, and text similarity are used for comment spam i...This paper proposes a novel approach to comment spam identification based on content analysis. Three main features including the number of links, content repetitiveness, and text similarity are used for comment spam identification. In practice, content repetitiveness is determined by the length and frequency of the longest common substring. Furthermore, text similarity is calculated using vector space model. The precisions of preliminary experiments on comment spam identification conducted on Chinese and English are as high as 93% and 82% respectively. The results show the validity and language independency of this approach. Compared with conventional spam filtering approaches, our method requires no training, no rule sets and no link relationships. The proposed approach can also deal with new comments as well as existing comments.展开更多
Since webpage classification is different from traditional text classification with its irregular words and phrases,massive and unlabeled features,which makes it harder for us to obtain effective feature.To cope with ...Since webpage classification is different from traditional text classification with its irregular words and phrases,massive and unlabeled features,which makes it harder for us to obtain effective feature.To cope with this problem,we propose two scenarios to extract meaningful strings based on document clustering and term clustering with multi-strategies to optimize a Vector Space Model(VSM) in order to improve webpage classification.The results show that document clustering work better than term clustering in coping with document content.However,a better overall performance is obtained by spectral clustering with document clustering.Moreover,owing to image existing in a same webpage with document content,the proposed method is also applied to extract image meaningful terms,and experiment results also show its effectiveness in improving webpage classification.展开更多
A syntactic and structural matching mechanism for service discovery was put forward, which tries to exploit the underlying semantics of web services to enhance tbe traditional syntactic service discovery. We commit WS...A syntactic and structural matching mechanism for service discovery was put forward, which tries to exploit the underlying semantics of web services to enhance tbe traditional syntactic service discovery. We commit WSDL （Web Service Description Language） as service description language. The syntactic matching mechanism is based on the textual similarity among WSDL documents using VSM （ Vector Space Model）. The structural information is extracted from WSDL document tree or the invocation sequence of a series of services which can be viewed as the problem of graph isomorphism. Then we combine the syntactic and structural similarity linearly to calculate the service similarity. Finally we provide a novel web services discovery framework named SG^＊ to find the exact services meeting the users＇ goals based on service similarity.展开更多
The texture analysis is often discussed in image processing domain, but most methods are limited within gray-level image or color image, and the present conception of texture is defined mainly based on gray-level imag...The texture analysis is often discussed in image processing domain, but most methods are limited within gray-level image or color image, and the present conception of texture is defined mainly based on gray-level image of single band. One of the essential characters of remote sensing image is multidimensional or even high-dimensional, and the traditional texture conception cannot contain enough information for these. Therefore, it is necessary to pursuit a proper texture definition based on remote sensing images, which is the first discussion in this paper. This paper describes the mapping model of spectral vector in two-dimensional image space using Markov random field (MRF), establishes a texture model of multiband remote sensing image based on MRF, and analyzes the calculations of Gibbs potential energy and Gibbs parameters. Further, this paper also analyzes the limitations of the traditional Gibbs model, prefers a new Gibbs model avoiding estimation of parameters, and presents a new texture segmentation algorithm for hy-perspectral remote sensing image later.展开更多
In this paper, I continue the study of the mathematical models presented in [J. C. Larsen, Models of cancer growth, J. Appl. Math. Comput. 53（1-2） （2015） 613-645] and [J. C. Larsen, The bistability theorem in a mo...In this paper, I continue the study of the mathematical models presented in [J. C. Larsen, Models of cancer growth, J. Appl. Math. Comput. 53（1-2） （2015） 613-645] and [J. C. Larsen, The bistability theorem in a model of metastatic cancer, to appear in Appl. Math.]. I shall prove the bistability theorem for the ODE model from [Larsen, 2015]. It is a mass action kinetic system in the variables C cancer, GF growth factor and GI growth inhibitor. This theorem says that for some values of the parameters, there exist two positive singular points c＊＋ = （C＊＋, GF＊., GI＊＋）, c＊2- = （C＊-, GF＊, GI＊-） of the vector field. Here C＊- 〈 C＊＋ and e. is stable and c＊＋ is unstable, see Sec. 2. There is also a discrete model in [Larsen, 2015], it is a linear map （T） on three-dimensional Euclidean vector space with variables （C, GF, GI）, where these variables have the same meaning as in the ODE model above. In [Larsen, 2015], I showed that one can sometimes find attine vector fields on three-dimensional Euclidean vector space whose time one map is T. I shall also show this in the present paper in a more general setting than in [Larsen, 2015]. This enables me to find an expression for the rate of change of cancer growth on the coordinate hyperplane C = 0 in Euclidean vector space. I also present an ODE model of cancer metastasis with variables C, CM, CF,GI, where C is primary cancer and CM is metastatic cancer and GF, GI are growth factors and growth inhibitors, respectively.展开更多
文摘A numerical model for steady state analysis and analytical expressions for the AM and FM modulation responses of DFB lasers are presented.The small signal modulation responses of 3 phase shift(PS) DFB is investigated for the first time.A new method(Vector Newton method) to obtain multiple longitudinal mode of DFB lasers is used.It is demonstrated that this method is suitable for obtaining multiple solution of high nonlinear equations.Longitudinal photon density distribution and multiple longitudinal mode of 3PS DFB and simple DFB lasers are analyzed.The results show that modulation response characteristics of 3PS DFB laser is as good as that of DFB,and PS can weaken the longitudinal spatial hole burning (LHSB) effect and is in favor of single longitudinal mode operating of lasers.
文摘In this paper, using the theory of L _fuzzy topological vector spaces [1]-[6] , we study some properties of L _fuzzy inductive topologies determined by a family of L _fuzzy linerar order_homomorphisms [2] of L _ftvs, and give a characterization of inductive topologies determined by a single FLOH. As an application of this results, we prove that the quotient space of L _ftvs is also L _ftvs.
基金Supported by the National Natural Science Foundation of China (No.60736044, 60803094)
文摘This paper proposes a novel approach to comment spam identification based on content analysis. Three main features including the number of links, content repetitiveness, and text similarity are used for comment spam identification. In practice, content repetitiveness is determined by the length and frequency of the longest common substring. Furthermore, text similarity is calculated using vector space model. The precisions of preliminary experiments on comment spam identification conducted on Chinese and English are as high as 93% and 82% respectively. The results show the validity and language independency of this approach. Compared with conventional spam filtering approaches, our method requires no training, no rule sets and no link relationships. The proposed approach can also deal with new comments as well as existing comments.
基金supported by the National Natural Science Foundation of China under Grants No.61100205,No.60873001the HiTech Research and Development Program of China under Grant No.2011AA010705the Fundamental Research Funds for the Central Universities under Grant No.2009RC0212
文摘Since webpage classification is different from traditional text classification with its irregular words and phrases,massive and unlabeled features,which makes it harder for us to obtain effective feature.To cope with this problem,we propose two scenarios to extract meaningful strings based on document clustering and term clustering with multi-strategies to optimize a Vector Space Model(VSM) in order to improve webpage classification.The results show that document clustering work better than term clustering in coping with document content.However,a better overall performance is obtained by spectral clustering with document clustering.Moreover,owing to image existing in a same webpage with document content,the proposed method is also applied to extract image meaningful terms,and experiment results also show its effectiveness in improving webpage classification.
文摘A syntactic and structural matching mechanism for service discovery was put forward, which tries to exploit the underlying semantics of web services to enhance tbe traditional syntactic service discovery. We commit WSDL （Web Service Description Language） as service description language. The syntactic matching mechanism is based on the textual similarity among WSDL documents using VSM （ Vector Space Model）. The structural information is extracted from WSDL document tree or the invocation sequence of a series of services which can be viewed as the problem of graph isomorphism. Then we combine the syntactic and structural similarity linearly to calculate the service similarity. Finally we provide a novel web services discovery framework named SG^＊ to find the exact services meeting the users＇ goals based on service similarity.
基金Supported by the National Key Basic Research and Development Program(No.2006CB701303, No. 2004CB318206)
文摘The texture analysis is often discussed in image processing domain, but most methods are limited within gray-level image or color image, and the present conception of texture is defined mainly based on gray-level image of single band. One of the essential characters of remote sensing image is multidimensional or even high-dimensional, and the traditional texture conception cannot contain enough information for these. Therefore, it is necessary to pursuit a proper texture definition based on remote sensing images, which is the first discussion in this paper. This paper describes the mapping model of spectral vector in two-dimensional image space using Markov random field (MRF), establishes a texture model of multiband remote sensing image based on MRF, and analyzes the calculations of Gibbs potential energy and Gibbs parameters. Further, this paper also analyzes the limitations of the traditional Gibbs model, prefers a new Gibbs model avoiding estimation of parameters, and presents a new texture segmentation algorithm for hy-perspectral remote sensing image later.
文摘In this paper, I continue the study of the mathematical models presented in [J. C. Larsen, Models of cancer growth, J. Appl. Math. Comput. 53（1-2） （2015） 613-645] and [J. C. Larsen, The bistability theorem in a model of metastatic cancer, to appear in Appl. Math.]. I shall prove the bistability theorem for the ODE model from [Larsen, 2015]. It is a mass action kinetic system in the variables C cancer, GF growth factor and GI growth inhibitor. This theorem says that for some values of the parameters, there exist two positive singular points c＊＋ = （C＊＋, GF＊., GI＊＋）, c＊2- = （C＊-, GF＊, GI＊-） of the vector field. Here C＊- 〈 C＊＋ and e. is stable and c＊＋ is unstable, see Sec. 2. There is also a discrete model in [Larsen, 2015], it is a linear map （T） on three-dimensional Euclidean vector space with variables （C, GF, GI）, where these variables have the same meaning as in the ODE model above. In [Larsen, 2015], I showed that one can sometimes find attine vector fields on three-dimensional Euclidean vector space whose time one map is T. I shall also show this in the present paper in a more general setting than in [Larsen, 2015]. This enables me to find an expression for the rate of change of cancer growth on the coordinate hyperplane C = 0 in Euclidean vector space. I also present an ODE model of cancer metastasis with variables C, CM, CF,GI, where C is primary cancer and CM is metastatic cancer and GF, GI are growth factors and growth inhibitors, respectively.
