Showing papers by "Nanjing University of Science and Technology published in 2005"
TL;DR: A two-phase KFD framework is developed, i.e., kernel principal component analysis (KPCA) plus Fisher linear discriminant analysis (LDA), which provides novel insights into the nature of KFD.
Abstract: This paper examines the theory of kernel Fisher discriminant analysis (KFD) in a Hilbert space and develops a two-phase KFD framework, i.e., kernel principal component analysis (KPCA) plus Fisher linear discriminant analysis (LDA). This framework provides novel insights into the nature of KFD. Based on this framework, the authors propose a complete kernel Fisher discriminant analysis (CKFD) algorithm. CKFD can be used to carry out discriminant analysis in "double discriminant subspaces." The fact that, it can make full use of two kinds of discriminant information, regular and irregular, makes CKFD a more powerful discriminator. The proposed algorithm was tested and evaluated using the FERET face database and the CENPARMI handwritten numeral database. The experimental results show that CKFD outperforms other KFD algorithms.
856 citations
TL;DR: This note provides an improved asymptotic stability condition for time-delay systems in terms of a strict linear matrix inequality that avoids bounding certain cross terms which often leads to conservatism.
Abstract: This note provides an improved asymptotic stability condition for time-delay systems in terms of a strict linear matrix inequality. Unlike previous methods, the mathematical development avoids bounding certain cross terms which often leads to conservatism. When time-varying norm-bounded uncertainties appear in a delay system, an improved robust delay-dependent stability condition is also given. Examples are provided to demonstrate the reduced conservatism of the proposed conditions.
536 citations
TL;DR: Experimental results on Concordia University CENPARMI database of handwritten Arabic numerals and Yale face database show that recognition rate is far higher than that of the algorithm adopting single feature or the existing fusion algorithm.
469 citations
TL;DR: Experimental results show that the new block cipher based on the chaotic standard map has satisfactory security with a low cost, which makes it a potential candidate for encryption of multimedia data such as images, audios and even videos.
Abstract: Due to their features of ergodicity, sensitivity to initial conditions and sensitivity to control parameters, etc., chaotic maps have good potential for information encryption. In this paper, a block cipher based on the chaotic standard map is proposed, which is composed of three parts: a confusion process based on chaotic standard map, a diffusion function, and a key generator. The parameter sensitivity of the standard map is analyzed, and the confusion process based on it is proposed. A diffusion function with high diffusion speed is designed, and a key generator based on the chaotic skew tent map is derived. Some cryptanalysis on the security of the designed cipher is carried out, and its computational complexity is analyzed. Experimental results show that the new cipher has satisfactory security with a low cost, which makes it a potential candidate for encryption of multimedia data such as images, audios and even videos.
417 citations
TL;DR: In this article, the effect of the aspect ratio of the plate and the volume fractions of the constituents on the centroidal deflection were scrutinized and the computed results were found to agree well with the solution of the problem.
386 citations
TL;DR: 2DLDA provides a sequentially optimal image compression mechanism, making the discriminant information compact into the up-left corner of the image, and suggests a feature selection strategy to select the most discriminative features from the corner.
309 citations
TL;DR: In this paper, NiO nanoparticles with an average size of 10nm were prepared by a solid-state reaction using nickel acetate and sodium hydroxide as the raw materials and the Tween 80 as dispersant.
296 citations
TL;DR: In this paper, the effects of the volume fraction of the suspended magnetic particles, concentration of surfactants and the external magnetic field strength as well as its orientation on the transport properties of the magnetic fluid are analyzed.
261 citations
TL;DR: The purpose is the design of a full-order fuzzy dynamic output feedback controller which ensures the robust asymptotic stability of the closed-loop system and guarantees an H/sub /spl infin// norm bound constraint on disturbance attenuation for all admissible uncertainties.
Abstract: This work investigates the problem of robust output feedback H/sub /spl infin// control for a class of uncertain discrete-time fuzzy systems with time delays. The state-space Takagi-Sugeno fuzzy model with time delays and norm-bounded parameter uncertainties is adopted. The purpose is the design of a full-order fuzzy dynamic output feedback controller which ensures the robust asymptotic stability of the closed-loop system and guarantees an H/sub /spl infin// norm bound constraint on disturbance attenuation for all admissible uncertainties. In terms of linear matrix inequalities (LMIs), a sufficient condition for the solvability of this problem is presented. Explicit expressions of a desired output feedback controller are proposed when the given LMIs are feasible. The effectiveness and the applicability of the proposed design approach are demonstrated by applying this to the problem of robust H/sub /spl infin// control for a class of uncertain nonlinear discrete delay systems.
258 citations
TL;DR: Improved conditions for the existence of a unique equilibrium point and its global asymptotic stability of cellular neural networks with time delay are provided by using more general Lyapunov-Krasovskii functionals.
Abstract: This brief provides improved conditions for the existence of a unique equilibrium point and its global asymptotic stability of cellular neural networks with time delay. Both delay-dependent and delay-independent conditions are obtained by using more general Lyapunov-Krasovskii functionals. These conditions are expressed in terms of linear matrix inequalities, which can be checked easily by recently developed standard algorithms. Examples are provided to demonstrate the reduced conservatism of the proposed criteria by numerically comparing with those reported recently in the literature.
225 citations
25 Nov 2005-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, equal channel angular pressing (ECAP) was applied to a wrought magnesium alloy AZ31 for up to 8 passes at temperatures as low as 100 ˚ C. The application of a back pressure was critical in deforming Mg alloys at lower temperatures.
Abstract: Equal channel angular pressing (ECAP) was applied to a wrought magnesium alloy AZ31 for up to 8 passes at temperatures as low as 100 °C. The application of a back pressure was critical in deforming Mg alloys at lower temperatures. Room temperature mechanical properties were obtained by tensile and hardness tests. With increasing ECAP strain, the initial coarse grained structure was transformed into a submicrometer-grained microstructure. In general, hardness increased with decreasing grain size although the changes in tensile strength and ductility were more complicated.
TL;DR: In this paper, a sufficient condition guaranteeing the existence, uniqueness and global exponential stability of an equilibrium point of such a kind of delayed neural networks is proposed, which is dependent on the size of the time delay.
TL;DR: In this paper, the effects of carbon fiber content on hardness and tribological properties of composite materials were studied with a Scanning Electron Microscope (SEM) and the results showed that the hardness and wear resistance of CF-reinforced UHMWPE composites increased with CF content.
TL;DR: An H∞ control design approach is developed using basis-dependent Lyapunov function for a class of discrete-time fuzzy systems with uncertainty that leads to some sufficient results in the form of strict linear matrix inequalities (LMIs).
TL;DR: The security of Fridrich's algorithm against brute-force attack, statistical attack, known-plain text attack and select-plaintext attack is analyzed by investigating the properties of the involved chaotic maps and diffusion functions.
Abstract: The security of Fridrich's algorithm against brute-force attack, statistical attack, known-plaintext attack and select-plaintext attack is analyzed by investigating the properties of the involved chaotic maps and diffusion functions. Based on the given analyses, some means are proposed to strengthen the overall performance of the focused cryptosystem.
TL;DR: This paper investigates the stabilizability of linear systems with closed-loop positivity by determining a necessary and sufficient condition for the existence of desired state-feedback controllers guaranteeing the resultant closed- loop system to be asymptotically stable and positive.
Abstract: This paper investigates the stabilizability of linear systems with closed-loop positivity. A necessary and sufficient condition for the existence of desired state-feedback controllers guaranteeing the resultant closed-loop system to be asymptotically stable and positive is obtained. Both continuous and discrete-time cases are considered, and all of the conditions are expressed as linear matrix inequalities which can be easily verified by using standard numerical software. Numerical examples are provided to illustrate the proposed conditions.
01 Jan 2005
TL;DR: In this paper, the robust stability analysis for interval neural networks with multiple time-varying delays and parameter uncertainties is studied, and a sufficient condition is obtained by means of Lyapunov functionals, which guarantees the existence, uniqueness and global asymptotic stability of the delayed neural network.
TL;DR: Nanosized ZSM-5 zeolite was successively synthesized in the absence of organic template by hydrothermal method as discussed by the authors, which was synthesized at 180 °C for 24 h after stirring at high speed and aging in the synthesis mixture with the molar composition of 12Na2O:100SiO2:2Al2O3:2500 H2O.
TL;DR: To look for high energy density materials (HEDM), the relationships between the structures and the performances of polynitroadamantanes (PNAs) were studied and PNA (1,2,3,4,5,6,7,8,9,10-) is recommended as the target of HEDM with insensitivity.
Abstract: To look for high energy density materials (HEDM), the relationships between the structures and the performances of polynitroadamantanes (PNAs) were studied. The assigned infrared spectra of PNAs obtained at the density functional theory (DFT) B3LYP/6-31G* level were used to compute the thermodynamic properties on the basis of the principle of statistical thermodynamics. The thermodynamic properties are linearly related with the number of nitro groups as well as with the temperatures. Detonation properties of PNAs were evaluated by using the Kamlet-Jacobs equation based on the calculated densities and heats of formation for titled compounds, and it is found that only when the number of nitro groups of PNA is equal to or more than eight can it be possible for PNAs to be used as HEDMs. The relative stabilities of PNAs were studied by the pyrolysis mechanism using the UHF-PM3 method. The homolysis of the C-NO 2 bond is predicted to be the initial step of thermal decomposition. The activation energies (E a ) for the homolysis decrease with the number of nitro groups being increased on the whole. The stability order of dinitroadamantane isomers derived from the interactions among nitro groups is consistent with what is determined by E a . The relations between the E a 's and the electronic structure parameters were discussed. In combination with the stability, PNA (1,2,3,4,5,6,7,8,9,10-) is recommended as the target of HEDM with insensitivity.
TL;DR: In this article, a design algorithm for a state feedback controller which guarantees that the closed-loop dynamics will be regular, impulse free, and stochastically stable is proposed in terms of the solutions to linear matrix inequalities.
Abstract: This paper deals with the class of continuous-time singular linear systems with Markovian jump parameters and time delays. Sufficient conditions on the stochastic stability and stochastic stabilizability are developed. A design algorithm for a state feedback controller which guarantees that the closed-loop dynamics will be regular, impulse free, and stochastically stable is proposed in terms of the solutions to linear matrix inequalities.
TL;DR: The experiment using a subset of FERET database indicates that the proposed kernel ICA method significantly outperform ICA, PCA and KPCA in terms of the total recognition rate.
TL;DR: In this article, an improved delay-dependent asymptotic stability criterion is developed without using bounding techniques on the related cross product terms, which significantly improves the allowed upper bounds of the delay size over some existing ones in the literature.
Abstract: This paper deals with the problem of robust stability analysis for uncertain neutral systems. In terms of a linear matrix inequality (LMI), an improved delay-dependent asymptotic stability criterion is developed without using bounding techniques on the related cross product terms. Based on this, a new delay-dependent LMI condition for robust stability is obtained. Numerical examples are provided to show that the proposed results significantly improve the allowed upper bounds of the delay size over some existing ones in the literature. Copyright © 2005 John Wiley & Sons, Ltd.
Journal Article•
TL;DR: The outstanding advantage of Tent map is discussed to compare with the hybrid algorithms based on chaotic map, and a hybrid optimization algorithm with higher search speed is constructed.
Abstract: The outstanding advantage of Tent map is discussed to compare with the hybrid algorithms based on chaotic map. Combined with the pattern search algorithm, a hybrid optimization algorithm with higher search speed is constructed. Examples show the feasibility of the algorithm, as well as the practicability of Tent map.
TL;DR: This paper tries an opposite direction to extract features for any vector pattern by first matrixizing it into a matrix pattern and then applying the matrixized versions of PCA and FLDA, MatPCA and MatFLDA, to the pattern.
04 Mar 2005
TL;DR: Simplified delay-dependent asymptotic stability conditions are provided for time-delay systems in terms of linear matrix inequalities and it is shown that the bounding technique does not have to be used in the derivation of these results.
Abstract: Simplified delay-dependent asymptotic stability conditions are provided for time-delay systems in terms of linear matrix inequalities. The redundant variables in the previous results derived by the so-called 'descriptor system approach' together with recently proposed bounding techniques are removed. Thus, the newly proposed conditions are equivalent to these obtained by the descriptor system approach but with reduced complexity. It is shown that the bounding technique does not have to be used in the derivation of our results. By the proposed method, delay-dependent results on H/sub /spl infin// performance analysis for time delay systems are also presented.
TL;DR: In this paper, a delay-dependent condition for the existence of robust H/sub/spl infin// filters is proposed, which is less conservative than existing ones in the literature.
Abstract: This paper is concerned with the problem of robust H/sub /spl infin// filtering for linear systems with both discrete and distributed delays, which are subject to norm-bounded time-varying parameter uncertainties. Both the state and measurement equations are assumed to have discrete and distributed delays. A delay-dependent condition for the existence of H/sub /spl infin// filters is proposed, which is less conservative than existing ones in the literature. Via solutions to certain linear matrix inequalities, general full-order filters are designed that ensure asymptotic stability and a prescribed H/sub /spl infin// performance level, irrespective of the parameter uncertainties. An illustrative example is provided to demonstrate the effectiveness and the reduced conservatism of the proposed method.
TL;DR: In this paper, a QSAR study on N-containing corrosion inhibitors has been made using quantum chemical approach assisted by a novel topological index (Xv#2) and two models were obtained and their efficiency was examined using statistics.
Abstract: In this paper, QSAR study on N-containing corrosion inhibitors has been made using quantum chemical approach assisted by a novel topological index (Xv#2). Two models were obtained and their efficiency was examined using statistics. The results indicate that inhibition efficiencies relate to some parameters of corrosion inhibitors, such as Ehomo, polarizability, Dipole, frontier orbital charge density, the interaction mode between inhibitors and metal surface (feedback donor–acceptor coordination bonds), Xv#2 (steric hindrance of molecules). Predicted values are consistent with the experimental ones on the whole. The residuals range within the experimental error. So the models can be used to predict inhibition efficiencies of the same type molecules.
TL;DR: This method, named as discrete time transfer matrix method of multibody system (MS-DT-TMM), combines and expands the advantages of the transfer matrix methods, and provides a powerful tool for the study of multi-rigid-body system dynamics.
Abstract: A new method for multibody system dynamics is proposed in this paper This method, named as discrete time transfer matrix method of multibody system (MS-DT-TMM), combines and expands the advantages of the transfer matrix method (TMM), transfer matrix method of vibration of multibody system (MS-TMM), discrete time transfer matrix method (DT-TMM) and the numerical integration procedure It does not need the global dynamics equations for the study of multibody system dynamics It has the modeling flexibility and a small size of matrices, and can be applied to a wide range of problems including multi-rigid-body system dynamics and multi-flexible-body system dynamics This method is simple, straightforward, practical, and provides a powerful tool for the study of multibody system dynamics Formulations of the method as well as some numerical examples of multi-rigid-body system dynamics and multi-flexible-body system dynamics to validate the method are given