Focused crawlers are important tools to support applications such as specialized Web portals, online searching, and Web search engines. A topic driven crawler chooses the best URLs and relevant pages to pursue during ...Focused crawlers are important tools to support applications such as specialized Web portals, online searching, and Web search engines. A topic driven crawler chooses the best URLs and relevant pages to pursue during Web crawling. It is difficult to deal with irrelevant pages. This paper presents a novel focused crawler framework. In our focused crawler, we propose a method to overcome some of the limitations of dealing with the irrelevant pages. We also introduce the implementation of our focused crawler and present some important metrics and an evaluation function for ranking pages relevance. The experimental result shows that our crawler can obtain more ＂important＂ pages and has a high precision and recall value.展开更多
Rank reversals appearing in AHP are discussed. It is proved with examples that they are in certain degree universal in the process of decision making. The mechanism of rank reversal is expounded. It is believed that...Rank reversals appearing in AHP are discussed. It is proved with examples that they are in certain degree universal in the process of decision making. The mechanism of rank reversal is expounded. It is believed that rank reversal can not deny the reasonableness of AHP and the axioms of independences of irrelevant alternatives.展开更多
Confounding of three binary-variable counterfactual model with directed acyclic graph (DAG) is discussed in this paper. According to the effect between the control variable and the covariate variable, we investigate t...Confounding of three binary-variable counterfactual model with directed acyclic graph (DAG) is discussed in this paper. According to the effect between the control variable and the covariate variable, we investigate three causal counterfactual models: the control variable is independent of the covariate variable, the control variable has the effect on the covariate variable and the covariate variable affects the control variable. Using the ancillary information based on conditional independence hypotheses and ignorability, the sufficient conditions to determine whether the covariate variable is an irrelevant factor or whether there is no confounding in each counterfactual model are obtained.展开更多
Multinomial logistic regression (MNL) is an attractive statistical approach in modeling the vehicle crash severity as it does not require the assumption of normality, linearity, or homoscedasticity compared to other a...Multinomial logistic regression (MNL) is an attractive statistical approach in modeling the vehicle crash severity as it does not require the assumption of normality, linearity, or homoscedasticity compared to other approaches, such as the discriminant analysis which requires these assumptions to be met. Moreover, it produces sound estimates by changing the probability range between 0.0 and 1.0 to log odds ranging from negative infinity to positive infinity, as it applies transformation of the dependent variable to a continuous variable. The estimates are asymptotically consistent with the requirements of the nonlinear regression process. The results of MNL can be interpreted by both the regression coefficient estimates and/or the odd ratios (the exponentiated coefficients) as well. In addition, the MNL can be used to improve the fitted model by comparing the full model that includes all predictors to a chosen restricted model by excluding the non-significant predictors. As such, this paper presents a detailed step by step overview of incorporating the MNL in crash severity modeling, using vehicle crash data of the Interstate I70 in the State of Missouri, USA for the years (2013-2015).展开更多
In this paper, we propose a dynamic multi-descriptor fusion （DMDF） approach to improving the retrieval accuracy of 3-dimensional （3D） model retrieval systems. First, an independent retrieval list is generated by u...In this paper, we propose a dynamic multi-descriptor fusion （DMDF） approach to improving the retrieval accuracy of 3-dimensional （3D） model retrieval systems. First, an independent retrieval list is generated by using each individual descriptor. Second, we propose an automatic relevant/irrelevant models selection （ARMS） approach to selecting the relevant and irrelevant 3D models automatically without any user interaction. A weighted distance, in which the weight associated with each individual descriptor is learnt by using the selected relevant and irrelevant models, is used to measure the similarity between two 3D models. Furthermore, a descriptor-dependent adaptive query point movement （AQPM） approach is employed to update every feature vector. This set of new feature vectors is used to index 3D models in the next search process. Four 3D model databases are used to compare the retrieval accuracy of our proposed DMDF approach with several descriptors as well as some well-known information fusion methods. Experimental results have shown that our proposed DMDF approach provides a promising retrieval result and always yields the best retrieval accuracy.展开更多
This paper proposed a novel feature selection method LUIFS （ latent utility of irrelevant feature selection） that not only selects the relevant features, but also targets at discovering the latent useful irrelevant ...This paper proposed a novel feature selection method LUIFS （ latent utility of irrelevant feature selection） that not only selects the relevant features, but also targets at discovering the latent useful irrelevant attributes by measuring their supportive importance to other attributes. The method minimizes the information lost and simultaneously maximizes the final classification accuracy. The classification error rates of the LUIFS method on 16 real-life datasets from UCI machine learning repository were evaluated using the ID3, Na^ve-Bayes, and IB （instance-based classifier） learning algorithms, respectively; and compared with those of the same algorithms with no feature selection （NoFS）, feature subset selection （FSS）, and correlation-based feature selection （CFS）. The empirical results demonstrate that the LUIFS can improve the performance of learning algorithms by taking the latent relevance for irrelevant attributes into consideration, and hence including those potentially important attributes into the optimal feature subset for classification.展开更多
Introduction. Secondary alterations of executive functions occur in brain injuries together with the primary neuropsychological symptoms, irrespective of the location of the damage and the affected neural networks. Su...Introduction. Secondary alterations of executive functions occur in brain injuries together with the primary neuropsychological symptoms, irrespective of the location of the damage and the affected neural networks. Such secondary alterations of executive functions in the presence of language alterations, which is the most frequent primary neuropsychological alteration, in addition to exacerbating the linguistic processing deficit, may be associated to multiple factors inherent to the brain injury or the injured patient. Purpose. To describe the secondary neuropsychological alterations of executive functions in elderly patients with low education levels with acquired language disorders and determine general factors of the injury and of the injured patient (etiology, location, time of recovery from the injury, age, education level), associated to such secondary alterations of the Attentional Control System. Patients and Methods. The study was conducted on 68 elderly patients with a low education level with language acquired disorders, of both sexes, ranging between 60 and 80 years of age. The executive functions explored included cognitive flexibility, impulsivity control and inhibition of irrelevant automatisms, with the Trail Making Test, the Porteus Maze Test and series of loops. Statistical processing involved a Distribution of Frequencies and Multiple Ordinal Regression. Results and Conclusions. The statistical analysis found secondary neuropsychological alterations of the executive functioning in the elderly patients with language disorders of the study that are associated to the location and the time of recovery from the injury and are irrespective of age, education level and etiology of the injury.展开更多
This paper has used the Arbitrage Theorem (Gordan Theorem) to show that first, all securities are derivatives for each other, and they are priced by the same risk neutral probability measure. Second, after the firm ch...This paper has used the Arbitrage Theorem (Gordan Theorem) to show that first, all securities are derivatives for each other, and they are priced by the same risk neutral probability measure. Second, after the firm changes its debt-equity ratio, the equityholders can always combine the new equity with other existing securities to create a home-made equity which will give exactly the same time-1 payoff of the old equity. That is, we have a capital structure irrelevancy proposition: changes in firms’ debt-equity ratios will not affect equityholders’ wealth (welfare), and equityholders’ preferences toward variance are irrelevant. Third, when the firm moves from a more certain project to a more uncertain one, the time-0 price of equity will increase, but (because the time-1 payoff of common bond has an upper bound) the time-0 price of common bond will decrease. Fourth, different labor contractual arrangements will not affect the time-0 price of labor input. When the firm moves from a more certain project to a more uncertain one, the time-0 price of labor input will increase if it is under the share or the mixed contract.展开更多
Employing a 4-form ansatz of 11-dimensional supergravity over a non-dynamical AdS_(4)×S^(7)/Z_(k)background and setting the internal space as an S1 Hopf fibration on CP3,we obtain a consistent truncation.The(pseu...Employing a 4-form ansatz of 11-dimensional supergravity over a non-dynamical AdS_(4)×S^(7)/Z_(k)background and setting the internal space as an S1 Hopf fibration on CP3,we obtain a consistent truncation.The(pseudo)scalars,in the resulting scalar equations in Euclidean AdS_(4)space,may be considered to arise from(anti)M-branes wrapping around the internal directions in the(Wick-rotated)skew-whiffed M2-brane background(as the resulting theory is for anti-M2-branes),thus realizing the modes after swapping the three fundamental representations 8_(s),8_(c),and 8_(v) of SO(8).Taking the backreaction on the external and internal spaces,we obtain the massless and massive modes,corresponding to exactly marginal and marginally irrelevant deformations on the boundary CFT3,respectively.Subsequently,we obtain a closed solution for the bulk equation and compute its correction with respect to the background action.Next,considering the Higgs-like(breathing)mode m^(2)=18,having all supersymmetries as well as parity and scale-invariance broken,solving the associated bulk equation with mathematical methods,specifically the Adomian decomposition method,and analyzing the behavior near the boundary of the solutions,we realize the boundary duals in the SU(4)×U(1)-singlet sectors of the ABJM model.Then,introducing the new dual deformationΔ_(+)=3,6 operators made of bi-fundamental scalars,fermions,and U(1)gauge fields,we obtain the SO(4)-invariant solutions as small instantons on a three-sphere with the radius at infinity,which correspond to collapsing bulk bubbles leading to big-crunch singularities.展开更多
Accurate acceleration acquisition is a critical issue in the robotic exoskeleton system,but it is difficult to directly obtain the acceleration via the existing sensing systems.The existing algorithm-based acceleratio...Accurate acceleration acquisition is a critical issue in the robotic exoskeleton system,but it is difficult to directly obtain the acceleration via the existing sensing systems.The existing algorithm-based acceleration acquisition methods put more attention on finite-time convergence and disturbance suppression but ignore the error constraint and initial state irrelevant techniques.To this end,a novel radical bias function neural network(RBFNN)based fixed-time reconstruction scheme with error constraints is designed to realize high-performance acceleration estimation.In this scheme,a novel exponential-type barrier Lyapunov function is proposed to handle the error constraints.It also provides a unified and concise Lyapunov stability-proof template for constrained and non-constrained systems.Moreover,a fractional power sliding mode control law is designed to realize fixed-time convergence,where the convergence time is irrelevant to initial states or external disturbance,and depends only on the chosen parameters.To further enhance observer robustness,an RBFNN with the adaptive weight matrix is proposed to approximate and attenuate the completely unknown disturbances.Numerical simulation and human sub ject experimental results validate the unique properties and practical robustness.展开更多
This is a pedagogical review on TT^(-)deformation of two dimensional quantum field theories.It is based on three lectures which the author gave at ITP-CAS in December 2018.This review consists of four parts.The first ...This is a pedagogical review on TT^(-)deformation of two dimensional quantum field theories.It is based on three lectures which the author gave at ITP-CAS in December 2018.This review consists of four parts.The first part is a general introduction to TT^(-)deformation.Special emphasises are put on the deformed classical Lagrangian and the exact solvability of the spectrum.The second part focuses on the torus partition sum of the TT^(-)/JT^(-)deformed conformal field theories and modular invariance/covariance.In the third part,different perspectives of TT^(-)deformation are presented,including its relation to random geometry,2D topological gravity and holography.We summarize more recent developments until January 2021 in the last part.展开更多
[Purpose/significance]Interdisciplinary knowledge fusion plays a key role in promoting the development of interdisciplinary integration and providing new ideas for interdisciplinary cooperative research.This study set...[Purpose/significance]Interdisciplinary knowledge fusion plays a key role in promoting the development of interdisciplinary integration and providing new ideas for interdisciplinary cooperative research.This study sets out to identify potential interdisciplinary cooperative topics between Library and Information Science(LIS)and Computer Science.[Method/Process]We built an interdisciplinary co-word network to identify potential interdisciplinary cooperative topics by closed and opened irrelevant knowledge discovery methods.We also constructed the topic interdisciplinary cooperation potential index(TICPI)to calculate the interdisciplinary cooperation potential of the topic and found the best contact path of the cooperation topic by constructing the practicable value(PV)of the contact patch.[Result/Conclusion]The experimental data suggested that both methods can identify the same potential interdisciplinary cooperative topics,such as knowledge service&matrix decomposition,online comments&social media processing,academic text&generative adversarial network,network public opinion&smart home.Exploiting the cooperation potential of these topics can help the knowledge fusion between disciplines.展开更多
基金Supported by the National Natural Science Foun-dation of China (60373099)
文摘Focused crawlers are important tools to support applications such as specialized Web portals, online searching, and Web search engines. A topic driven crawler chooses the best URLs and relevant pages to pursue during Web crawling. It is difficult to deal with irrelevant pages. This paper presents a novel focused crawler framework. In our focused crawler, we propose a method to overcome some of the limitations of dealing with the irrelevant pages. We also introduce the implementation of our focused crawler and present some important metrics and an evaluation function for ranking pages relevance. The experimental result shows that our crawler can obtain more ＂important＂ pages and has a high precision and recall value.
文摘Rank reversals appearing in AHP are discussed. It is proved with examples that they are in certain degree universal in the process of decision making. The mechanism of rank reversal is expounded. It is believed that rank reversal can not deny the reasonableness of AHP and the axioms of independences of irrelevant alternatives.
文摘Confounding of three binary-variable counterfactual model with directed acyclic graph (DAG) is discussed in this paper. According to the effect between the control variable and the covariate variable, we investigate three causal counterfactual models: the control variable is independent of the covariate variable, the control variable has the effect on the covariate variable and the covariate variable affects the control variable. Using the ancillary information based on conditional independence hypotheses and ignorability, the sufficient conditions to determine whether the covariate variable is an irrelevant factor or whether there is no confounding in each counterfactual model are obtained.
文摘Multinomial logistic regression (MNL) is an attractive statistical approach in modeling the vehicle crash severity as it does not require the assumption of normality, linearity, or homoscedasticity compared to other approaches, such as the discriminant analysis which requires these assumptions to be met. Moreover, it produces sound estimates by changing the probability range between 0.0 and 1.0 to log odds ranging from negative infinity to positive infinity, as it applies transformation of the dependent variable to a continuous variable. The estimates are asymptotically consistent with the requirements of the nonlinear regression process. The results of MNL can be interpreted by both the regression coefficient estimates and/or the odd ratios (the exponentiated coefficients) as well. In addition, the MNL can be used to improve the fitted model by comparing the full model that includes all predictors to a chosen restricted model by excluding the non-significant predictors. As such, this paper presents a detailed step by step overview of incorporating the MNL in crash severity modeling, using vehicle crash data of the Interstate I70 in the State of Missouri, USA for the years (2013-2015).
基金supported in part by“MOST”under Grants No.102-2632-E-216-001-MY3 and No.104-2221-E-216-010-MY2
文摘In this paper, we propose a dynamic multi-descriptor fusion （DMDF） approach to improving the retrieval accuracy of 3-dimensional （3D） model retrieval systems. First, an independent retrieval list is generated by using each individual descriptor. Second, we propose an automatic relevant/irrelevant models selection （ARMS） approach to selecting the relevant and irrelevant 3D models automatically without any user interaction. A weighted distance, in which the weight associated with each individual descriptor is learnt by using the selected relevant and irrelevant models, is used to measure the similarity between two 3D models. Furthermore, a descriptor-dependent adaptive query point movement （AQPM） approach is employed to update every feature vector. This set of new feature vectors is used to index 3D models in the next search process. Four 3D model databases are used to compare the retrieval accuracy of our proposed DMDF approach with several descriptors as well as some well-known information fusion methods. Experimental results have shown that our proposed DMDF approach provides a promising retrieval result and always yields the best retrieval accuracy.
基金The Science and Technology Development Fund from Macao Government (No007/2006/A)
文摘This paper proposed a novel feature selection method LUIFS （ latent utility of irrelevant feature selection） that not only selects the relevant features, but also targets at discovering the latent useful irrelevant attributes by measuring their supportive importance to other attributes. The method minimizes the information lost and simultaneously maximizes the final classification accuracy. The classification error rates of the LUIFS method on 16 real-life datasets from UCI machine learning repository were evaluated using the ID3, Na^ve-Bayes, and IB （instance-based classifier） learning algorithms, respectively; and compared with those of the same algorithms with no feature selection （NoFS）, feature subset selection （FSS）, and correlation-based feature selection （CFS）. The empirical results demonstrate that the LUIFS can improve the performance of learning algorithms by taking the latent relevance for irrelevant attributes into consideration, and hence including those potentially important attributes into the optimal feature subset for classification.
文摘Introduction. Secondary alterations of executive functions occur in brain injuries together with the primary neuropsychological symptoms, irrespective of the location of the damage and the affected neural networks. Such secondary alterations of executive functions in the presence of language alterations, which is the most frequent primary neuropsychological alteration, in addition to exacerbating the linguistic processing deficit, may be associated to multiple factors inherent to the brain injury or the injured patient. Purpose. To describe the secondary neuropsychological alterations of executive functions in elderly patients with low education levels with acquired language disorders and determine general factors of the injury and of the injured patient (etiology, location, time of recovery from the injury, age, education level), associated to such secondary alterations of the Attentional Control System. Patients and Methods. The study was conducted on 68 elderly patients with a low education level with language acquired disorders, of both sexes, ranging between 60 and 80 years of age. The executive functions explored included cognitive flexibility, impulsivity control and inhibition of irrelevant automatisms, with the Trail Making Test, the Porteus Maze Test and series of loops. Statistical processing involved a Distribution of Frequencies and Multiple Ordinal Regression. Results and Conclusions. The statistical analysis found secondary neuropsychological alterations of the executive functioning in the elderly patients with language disorders of the study that are associated to the location and the time of recovery from the injury and are irrespective of age, education level and etiology of the injury.
文摘This paper has used the Arbitrage Theorem (Gordan Theorem) to show that first, all securities are derivatives for each other, and they are priced by the same risk neutral probability measure. Second, after the firm changes its debt-equity ratio, the equityholders can always combine the new equity with other existing securities to create a home-made equity which will give exactly the same time-1 payoff of the old equity. That is, we have a capital structure irrelevancy proposition: changes in firms’ debt-equity ratios will not affect equityholders’ wealth (welfare), and equityholders’ preferences toward variance are irrelevant. Third, when the firm moves from a more certain project to a more uncertain one, the time-0 price of equity will increase, but (because the time-1 payoff of common bond has an upper bound) the time-0 price of common bond will decrease. Fourth, different labor contractual arrangements will not affect the time-0 price of labor input. When the firm moves from a more certain project to a more uncertain one, the time-0 price of labor input will increase if it is under the share or the mixed contract.
文摘Employing a 4-form ansatz of 11-dimensional supergravity over a non-dynamical AdS_(4)×S^(7)/Z_(k)background and setting the internal space as an S1 Hopf fibration on CP3,we obtain a consistent truncation.The(pseudo)scalars,in the resulting scalar equations in Euclidean AdS_(4)space,may be considered to arise from(anti)M-branes wrapping around the internal directions in the(Wick-rotated)skew-whiffed M2-brane background(as the resulting theory is for anti-M2-branes),thus realizing the modes after swapping the three fundamental representations 8_(s),8_(c),and 8_(v) of SO(8).Taking the backreaction on the external and internal spaces,we obtain the massless and massive modes,corresponding to exactly marginal and marginally irrelevant deformations on the boundary CFT3,respectively.Subsequently,we obtain a closed solution for the bulk equation and compute its correction with respect to the background action.Next,considering the Higgs-like(breathing)mode m^(2)=18,having all supersymmetries as well as parity and scale-invariance broken,solving the associated bulk equation with mathematical methods,specifically the Adomian decomposition method,and analyzing the behavior near the boundary of the solutions,we realize the boundary duals in the SU(4)×U(1)-singlet sectors of the ABJM model.Then,introducing the new dual deformationΔ_(+)=3,6 operators made of bi-fundamental scalars,fermions,and U(1)gauge fields,we obtain the SO(4)-invariant solutions as small instantons on a three-sphere with the radius at infinity,which correspond to collapsing bulk bubbles leading to big-crunch singularities.
基金Project supported by the Move Robotics Technology Co.,Ltd.the National Natural Science Foundation of China(No.51705163)。
文摘Accurate acceleration acquisition is a critical issue in the robotic exoskeleton system,but it is difficult to directly obtain the acceleration via the existing sensing systems.The existing algorithm-based acceleration acquisition methods put more attention on finite-time convergence and disturbance suppression but ignore the error constraint and initial state irrelevant techniques.To this end,a novel radical bias function neural network(RBFNN)based fixed-time reconstruction scheme with error constraints is designed to realize high-performance acceleration estimation.In this scheme,a novel exponential-type barrier Lyapunov function is proposed to handle the error constraints.It also provides a unified and concise Lyapunov stability-proof template for constrained and non-constrained systems.Moreover,a fractional power sliding mode control law is designed to realize fixed-time convergence,where the convergence time is irrelevant to initial states or external disturbance,and depends only on the chosen parameters.To further enhance observer robustness,an RBFNN with the adaptive weight matrix is proposed to approximate and attenuate the completely unknown disturbances.Numerical simulation and human sub ject experimental results validate the unique properties and practical robustness.
基金It is a pleasure to thank Ofer Aharony,Shouvik Datta,Amit Giveon and David Kutasov for collaborations on the relevant projects that lead to this review.I thank Gang Yang for kind invitation and hospitality at ITP-CAS.Tm also indebted to Luis Apolo,Wei Li,Pujian Mao,Wei Song,Junbao Wu and Gang Yang for various helpful discussions.Many thanks to Alex Belin,Shouvik Datta,Amit Giveon,Madalena Lemos,Kostas Siampos,Wei Song,Roberto Tateo,Junbao Wu and Gang Yang for valuable feedbacks.
文摘This is a pedagogical review on TT^(-)deformation of two dimensional quantum field theories.It is based on three lectures which the author gave at ITP-CAS in December 2018.This review consists of four parts.The first part is a general introduction to TT^(-)deformation.Special emphasises are put on the deformed classical Lagrangian and the exact solvability of the spectrum.The second part focuses on the torus partition sum of the TT^(-)/JT^(-)deformed conformal field theories and modular invariance/covariance.In the third part,different perspectives of TT^(-)deformation are presented,including its relation to random geometry,2D topological gravity and holography.We summarize more recent developments until January 2021 in the last part.
基金National Social Science Foundation of China,Research on Identification of Interdisciplinary Potential Knowledge Growth Point and Innovation Trend Forecast(No.19ATQ006)。
文摘[Purpose/significance]Interdisciplinary knowledge fusion plays a key role in promoting the development of interdisciplinary integration and providing new ideas for interdisciplinary cooperative research.This study sets out to identify potential interdisciplinary cooperative topics between Library and Information Science(LIS)and Computer Science.[Method/Process]We built an interdisciplinary co-word network to identify potential interdisciplinary cooperative topics by closed and opened irrelevant knowledge discovery methods.We also constructed the topic interdisciplinary cooperation potential index(TICPI)to calculate the interdisciplinary cooperation potential of the topic and found the best contact path of the cooperation topic by constructing the practicable value(PV)of the contact patch.[Result/Conclusion]The experimental data suggested that both methods can identify the same potential interdisciplinary cooperative topics,such as knowledge service&matrix decomposition,online comments&social media processing,academic text&generative adversarial network,network public opinion&smart home.Exploiting the cooperation potential of these topics can help the knowledge fusion between disciplines.
