According to the stationary principle of potential energy and the generalized coordinate method, a stiffness matrix of a beam element considering distortion effects is derived. Using the stiffness matrix of the beam e...According to the stationary principle of potential energy and the generalized coordinate method, a stiffness matrix of a beam element considering distortion effects is derived. Using the stiffness matrix of the beam element, a finite element program for computing thin-walled box steel beams is developed. And the program can take the section distortion and warping effects into account. The influences of diaphragm spacing on the mechanical behavior of thin-walled box beams are analyzed by the program. The numerical analysis shows that setting diaphragms have the greatest influence on the distortion normal stress, while there is very little influence on the bending normal stress. Only when the distance of adjacent diaphragms decreases to a certain value, will the distortion normal stress in the thin-walled box beam obviously reduce under the distortion load. Finally, a distortion-warping coefficient γ is introduced for simplifying the calculation of the longitudinal normal stress of thin-walled box beams. When the ratio of diaphragms adjacent space L to the maximum section dimension H is less than 2, the distortion-warping coefficient γ tends to one, which means that the distortion normal stress of the thin-walled box beam tends to zero, and the effect of the section distortion can be ignored.展开更多
Finding solutions of matrix equations in given set SR n×n is an active research field. Lots of investigation have done for these cases, where S are the sets of general or symmetric matrices and symmetric posit...Finding solutions of matrix equations in given set SR n×n is an active research field. Lots of investigation have done for these cases, where S are the sets of general or symmetric matrices and symmetric positive definite or sysmmetric semiposite definite matrices respectively . Recently, however, attentions are been paying to the situation for S to be the set of general(semi) positive definite matrices(called as semipositive subdefinite matrices below) . In this paper the necessary and sufficient conditions for the following two kinds of matrix equations having semipositive, subdefinite solutions are obtained. General solutions and symmetric solutions of the equations (Ⅰ) and (Ⅱ) have been considered in in detail.展开更多
In order to forecast projectile impact points quickly and accurately,aprojectile impact point prediction method based on generalized regression neural network（GRNN）is presented.Firstly,the model of GRNN forecasting ...In order to forecast projectile impact points quickly and accurately,aprojectile impact point prediction method based on generalized regression neural network（GRNN）is presented.Firstly,the model of GRNN forecasting impact point is established;secondly,the particle swarm algorithm（PSD）is used to optimize the smooth factor in the prediction model and then the optimal GRNN impact point prediction model is obtained.Finally,the numerical simulation of this prediction model is carried out.Simulation results show that the maximum range error is no more than 40 m,and the lateral deviation error is less than0.2m.The average time of impact point prediction is 6.645 ms,which is 1 300.623 ms less than that of numerical integration method.Therefore,it is feasible and effective for the proposed method to forecast projectile impact points,and thus it can provide a theoretical reference for practical engineering applications.展开更多
In order to narrow the semantic gap existing in content-based image retrieval （CBIR）,a novel retrieval technology called auto-extended multi query examples （AMQE） is proposed.It expands the single one query image ...In order to narrow the semantic gap existing in content-based image retrieval （CBIR）,a novel retrieval technology called auto-extended multi query examples （AMQE） is proposed.It expands the single one query image used in traditional image retrieval into multi query examples so as to include more image features related with semantics.Retrieving images for each of the multi query examples and integrating the retrieval results,more relevant images can be obtained.The property of the recall-precision curve of a general retrieval algorithm and the K-means clustering method are used to realize the expansion according to the distance of image features of the initially retrieved images.The experimental results demonstrate that the AMQE technology can greatly improve the recall and precision of the original algorithms.展开更多
To further enhance the efficiencies of search engines,achieving capabilities of searching,indexing and locating the information in the deep web,latent semantic analysis is a simple and effective way.Through the latent...To further enhance the efficiencies of search engines,achieving capabilities of searching,indexing and locating the information in the deep web,latent semantic analysis is a simple and effective way.Through the latent semantic analysis of the attributes in the query interfaces and the unique entrances of the deep web sites,the hidden semantic structure information can be retrieved and dimension reduction can be achieved to a certain extent.Using this semantic structure information,the contents in the site can be inferred and the similarity measures among sites in deep web can be revised.Experimental results show that latent semantic analysis revises and improves the semantic understanding of the query form in the deep web,which overcomes the shortcomings of the keyword-based methods.This approach can be used to effectively search the most similar site for any given site and to obtain a site list which conforms to the restrictions one specifies.展开更多
The parallel multisection method for solving algebraic eigenproblem has been presented in recent years with the development of the parallel computers, but all the research work is limited in standard eigenproblems of ...The parallel multisection method for solving algebraic eigenproblem has been presented in recent years with the development of the parallel computers, but all the research work is limited in standard eigenproblems of symmetric tridiagonal matrix. The multisection method for solving the generalized eigenproblem applied significantly in many science and engineering domains has not been studied. The parallel region preserving multisection method (PRM for short) for solving generalized eigenproblems of large sparse and real symmetric matrix is presented in this paper. This method not only retains the advantages of the conventional determinant search method (DS for short), but also overcomes its disadvantages such as leaking roots and disconvergence. We have tested the method on the YH 1 vector computer, and compared it with the parallel region preserving determinant search method the parallel region preserving bisection method (PRB for short). The numerical results show that PRM has a higher speed up, for instance, it attains the speed up of 7.7 when the scale of the problem is 2 114 and the eigenpair found is 3, and PRM is superior to PRB when the scale of the problem is large.展开更多
The practice of four-character Chinese idioms alteration used in the signboards by substituting character （s） with their homophonous words has grown into a general trend. Fifty-one altered idioms are collected. The ...The practice of four-character Chinese idioms alteration used in the signboards by substituting character （s） with their homophonous words has grown into a general trend. Fifty-one altered idioms are collected. The majority of the modifiers are medium-small store owners. Idiom alteration for specific purpose differs from the idiom misinterpretation. Speedy economic growth and material wealth pursuit social context stimulate the idiom alteration behavior which enforces the pragmatism value orientation. By modifying idioms into four-character structures of strong practical effect, the obvious pragamtic value of the businessmen and of Chinese are manifested. A causal analysis method is used.展开更多
By using fixed point theorems,we consider multiplicity of positive solutions for second-order generalized Sturm-Liouville boundary value problem,where the first order derivative is involved in the nonlinear term expli...By using fixed point theorems,we consider multiplicity of positive solutions for second-order generalized Sturm-Liouville boundary value problem,where the first order derivative is involved in the nonlinear term explicitly.We show the existence of multiple positive solutions for the problems.Example is given to illustrate the main results of the article.展开更多
Architectural heritage comprises one o the most important elements of mountain settlements in Greece. It holds high cultural value, represents the tangible continuation of the past and forms the unique character and i...Architectural heritage comprises one o the most important elements of mountain settlements in Greece. It holds high cultural value, represents the tangible continuation of the past and forms the unique character and identity of each mountain region. Yet, controversy regarding funding for its preservation often arises. In this paper, we used two Contingent Valuation surveys to estimate the socia benefit deriving from protecting the traditiona architecture in the mountainous village of Sirako and through it, to examine perceptions and attitudes o local residents and visitors. Research findings revealed a strong social will in favor of the good＇s protection followed by high percentages of positive willingness to pay（WTP）. However, WTP is significantly higher among residents. Cultura heritage value, of the good, appears to prevail, along with the environmental one. However, both residents and visitors pointed out that local heritage, if wellpreserved, will boost tourism development. Residents appeared to better recognize the true level o architectural decay, expressed higher apprehension for its protection and were willing to pay higher amount of money. Tourists, on the other side expressed high satisfaction for their visit, appreciated the beauty and serenity emerging from local built and natural environment and spent several days visiting the surrounding area. The longer they stayed and gotfamiliar with the village, the more willing they were to contribute to local heritage＇s protection. Percentages reflecting indifference for protecting architecture were extremely low. Yet, they were higher among tourists. Traditional architecture is considered as public good; an opinion resulting in an important percentage of visitors stating that national government should provide the necessary funding. In addition, the architecture appears to hold a high level of topicality. Those descending from Sirako or emotionally connected to it, of both social groups,turned out to be more concerned about the good and with a stronger sense of responsibility for it. Usevalue of the good holds high economic value, as well,while higher percentages of zero WTP appeared among non-users. Research findings revealed social attitudes and perceptions on what constitutes architectural heritage, in its cultural and economic frame. If taken under consideration, they may form useful drivers for local, heritage-based, sustainable展开更多
This paper is concerned with the generalzed global solution and its asymptotic properties for the initial value problem of the partial differential equationu t+u x 3 =F(u).
What is the mental realization of our knowledge of the meaning of words？ Does the lexical side of our semantic competence depend on the fact that we have dedicated representations of the semantic properties of lexeme...What is the mental realization of our knowledge of the meaning of words？ Does the lexical side of our semantic competence depend on the fact that we have dedicated representations of the semantic properties of lexemes or does it arise from world knowledge, encyclopedic information, and non-linguistic categorization？ According to meaning eliminativism, lexical concepts have no robust psychological reality and our ability to use the words of a language should not be explained in terms of knowledge of their conventional semantic value, conceived as their array of possible senses. To start, I will briefly explain what meaning eliminativism is and illustrate the key arguments that have been offered in its defense. Then, I will argue that such arguments are not as persuasive as they wish, and I will show that there are convincing theoretical and empirical reasons to maintain that meaning eliminativism is not a plausible claim about the nature of our lexical skills.展开更多
基金Specialized Research Fund for the Doctoral Program of Higher Education (No.20070247002)
文摘According to the stationary principle of potential energy and the generalized coordinate method, a stiffness matrix of a beam element considering distortion effects is derived. Using the stiffness matrix of the beam element, a finite element program for computing thin-walled box steel beams is developed. And the program can take the section distortion and warping effects into account. The influences of diaphragm spacing on the mechanical behavior of thin-walled box beams are analyzed by the program. The numerical analysis shows that setting diaphragms have the greatest influence on the distortion normal stress, while there is very little influence on the bending normal stress. Only when the distance of adjacent diaphragms decreases to a certain value, will the distortion normal stress in the thin-walled box beam obviously reduce under the distortion load. Finally, a distortion-warping coefficient γ is introduced for simplifying the calculation of the longitudinal normal stress of thin-walled box beams. When the ratio of diaphragms adjacent space L to the maximum section dimension H is less than 2, the distortion-warping coefficient γ tends to one, which means that the distortion normal stress of the thin-walled box beam tends to zero, and the effect of the section distortion can be ignored.
文摘Finding solutions of matrix equations in given set SR n×n is an active research field. Lots of investigation have done for these cases, where S are the sets of general or symmetric matrices and symmetric positive definite or sysmmetric semiposite definite matrices respectively . Recently, however, attentions are been paying to the situation for S to be the set of general(semi) positive definite matrices(called as semipositive subdefinite matrices below) . In this paper the necessary and sufficient conditions for the following two kinds of matrix equations having semipositive, subdefinite solutions are obtained. General solutions and symmetric solutions of the equations (Ⅰ) and (Ⅱ) have been considered in in detail.
基金Project Funded by Chongqing Changjiang Electrical Appliances Industries Group Co.,Ltd
文摘In order to forecast projectile impact points quickly and accurately,aprojectile impact point prediction method based on generalized regression neural network（GRNN）is presented.Firstly,the model of GRNN forecasting impact point is established;secondly,the particle swarm algorithm（PSD）is used to optimize the smooth factor in the prediction model and then the optimal GRNN impact point prediction model is obtained.Finally,the numerical simulation of this prediction model is carried out.Simulation results show that the maximum range error is no more than 40 m,and the lateral deviation error is less than0.2m.The average time of impact point prediction is 6.645 ms,which is 1 300.623 ms less than that of numerical integration method.Therefore,it is feasible and effective for the proposed method to forecast projectile impact points,and thus it can provide a theoretical reference for practical engineering applications.
基金The National High Technology Research and Develop-ment Program of China (863 Program) (No.2002AA413420).
文摘In order to narrow the semantic gap existing in content-based image retrieval （CBIR）,a novel retrieval technology called auto-extended multi query examples （AMQE） is proposed.It expands the single one query image used in traditional image retrieval into multi query examples so as to include more image features related with semantics.Retrieving images for each of the multi query examples and integrating the retrieval results,more relevant images can be obtained.The property of the recall-precision curve of a general retrieval algorithm and the K-means clustering method are used to realize the expansion according to the distance of image features of the initially retrieved images.The experimental results demonstrate that the AMQE technology can greatly improve the recall and precision of the original algorithms.
文摘To further enhance the efficiencies of search engines,achieving capabilities of searching,indexing and locating the information in the deep web,latent semantic analysis is a simple and effective way.Through the latent semantic analysis of the attributes in the query interfaces and the unique entrances of the deep web sites,the hidden semantic structure information can be retrieved and dimension reduction can be achieved to a certain extent.Using this semantic structure information,the contents in the site can be inferred and the similarity measures among sites in deep web can be revised.Experimental results show that latent semantic analysis revises and improves the semantic understanding of the query form in the deep web,which overcomes the shortcomings of the keyword-based methods.This approach can be used to effectively search the most similar site for any given site and to obtain a site list which conforms to the restrictions one specifies.
文摘The parallel multisection method for solving algebraic eigenproblem has been presented in recent years with the development of the parallel computers, but all the research work is limited in standard eigenproblems of symmetric tridiagonal matrix. The multisection method for solving the generalized eigenproblem applied significantly in many science and engineering domains has not been studied. The parallel region preserving multisection method (PRM for short) for solving generalized eigenproblems of large sparse and real symmetric matrix is presented in this paper. This method not only retains the advantages of the conventional determinant search method (DS for short), but also overcomes its disadvantages such as leaking roots and disconvergence. We have tested the method on the YH 1 vector computer, and compared it with the parallel region preserving determinant search method the parallel region preserving bisection method (PRB for short). The numerical results show that PRM has a higher speed up, for instance, it attains the speed up of 7.7 when the scale of the problem is 2 114 and the eigenpair found is 3, and PRM is superior to PRB when the scale of the problem is large.
文摘The practice of four-character Chinese idioms alteration used in the signboards by substituting character （s） with their homophonous words has grown into a general trend. Fifty-one altered idioms are collected. The majority of the modifiers are medium-small store owners. Idiom alteration for specific purpose differs from the idiom misinterpretation. Speedy economic growth and material wealth pursuit social context stimulate the idiom alteration behavior which enforces the pragmatism value orientation. By modifying idioms into four-character structures of strong practical effect, the obvious pragamtic value of the businessmen and of Chinese are manifested. A causal analysis method is used.
基金Supported by the University Foundation of Natural Science of Anhui Province(KJ2007B055)
文摘By using fixed point theorems,we consider multiplicity of positive solutions for second-order generalized Sturm-Liouville boundary value problem,where the first order derivative is involved in the nonlinear term explicitly.We show the existence of multiple positive solutions for the problems.Example is given to illustrate the main results of the article.
基金supported by Scientific Research Foundation for Youth Scholars, IGSNRR, CAS, entitled “Evaluation on the conservation and development of agricultural heritage systems in China”
文摘Architectural heritage comprises one o the most important elements of mountain settlements in Greece. It holds high cultural value, represents the tangible continuation of the past and forms the unique character and identity of each mountain region. Yet, controversy regarding funding for its preservation often arises. In this paper, we used two Contingent Valuation surveys to estimate the socia benefit deriving from protecting the traditiona architecture in the mountainous village of Sirako and through it, to examine perceptions and attitudes o local residents and visitors. Research findings revealed a strong social will in favor of the good＇s protection followed by high percentages of positive willingness to pay（WTP）. However, WTP is significantly higher among residents. Cultura heritage value, of the good, appears to prevail, along with the environmental one. However, both residents and visitors pointed out that local heritage, if wellpreserved, will boost tourism development. Residents appeared to better recognize the true level o architectural decay, expressed higher apprehension for its protection and were willing to pay higher amount of money. Tourists, on the other side expressed high satisfaction for their visit, appreciated the beauty and serenity emerging from local built and natural environment and spent several days visiting the surrounding area. The longer they stayed and gotfamiliar with the village, the more willing they were to contribute to local heritage＇s protection. Percentages reflecting indifference for protecting architecture were extremely low. Yet, they were higher among tourists. Traditional architecture is considered as public good; an opinion resulting in an important percentage of visitors stating that national government should provide the necessary funding. In addition, the architecture appears to hold a high level of topicality. Those descending from Sirako or emotionally connected to it, of both social groups,turned out to be more concerned about the good and with a stronger sense of responsibility for it. Usevalue of the good holds high economic value, as well,while higher percentages of zero WTP appeared among non-users. Research findings revealed social attitudes and perceptions on what constitutes architectural heritage, in its cultural and economic frame. If taken under consideration, they may form useful drivers for local, heritage-based, sustainable
文摘This paper is concerned with the generalzed global solution and its asymptotic properties for the initial value problem of the partial differential equationu t+u x 3 =F(u).
文摘What is the mental realization of our knowledge of the meaning of words？ Does the lexical side of our semantic competence depend on the fact that we have dedicated representations of the semantic properties of lexemes or does it arise from world knowledge, encyclopedic information, and non-linguistic categorization？ According to meaning eliminativism, lexical concepts have no robust psychological reality and our ability to use the words of a language should not be explained in terms of knowledge of their conventional semantic value, conceived as their array of possible senses. To start, I will briefly explain what meaning eliminativism is and illustrate the key arguments that have been offered in its defense. Then, I will argue that such arguments are not as persuasive as they wish, and I will show that there are convincing theoretical and empirical reasons to maintain that meaning eliminativism is not a plausible claim about the nature of our lexical skills.
