2007 No. 1
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2007, (1): 1-6.
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Abstract:
This paper proved Vukman's conjecture concerning the image of a linear derivation on a Banach algebra, gave some sufficient conditions that the image of a linear derivation on complex Banach algebra was in the Jacobson radical, and also discussed the simpleorm of a linear derivation on an annihilator Banach algebra.
This paper proved Vukman's conjecture concerning the image of a linear derivation on a Banach algebra, gave some sufficient conditions that the image of a linear derivation on complex Banach algebra was in the Jacobson radical, and also discussed the simpleorm of a linear derivation on an annihilator Banach algebra.
2007, (1): 7-12.
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The paper studied the eigenvalue problems for nonlinear second-order dynamic equations on time scales with m-point boundary conditions. Using Schauder'sand Krasnoselskii's fixed point theorems, the eigenvalues were characterized and the existence of positive solutions established. Several kinds of intervals ofλ were presented explicitly, in which the existence of at least one positive solution of BVP was guaranteed.
The paper studied the eigenvalue problems for nonlinear second-order dynamic equations on time scales with m-point boundary conditions. Using Schauder'sand Krasnoselskii's fixed point theorems, the eigenvalues were characterized and the existence of positive solutions established. Several kinds of intervals ofλ were presented explicitly, in which the existence of at least one positive solution of BVP was guaranteed.
2007, (1): 19-26.
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Using the method of integral average technique and defining a new prepared solution, this paper presented some new oscillation criteria of matrix differential equations with damping, which extend the results of Rogovchenko and Li for scalar cases and improve the results of Yang for matrix cases; a few examples was given at the end.
Using the method of integral average technique and defining a new prepared solution, this paper presented some new oscillation criteria of matrix differential equations with damping, which extend the results of Rogovchenko and Li for scalar cases and improve the results of Yang for matrix cases; a few examples was given at the end.
2007, (1): 27-35.
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This paper explored the existence of periodic solutions with strictly positive components and impulses of a nonautonomous ratio-dependent predator-prey system. Sufficient criteria were obtained for the existence of strictly positive periodic solutions. The approach was based on a continuation theorem in the coincidence degree theory as well as some prior estimates.
This paper explored the existence of periodic solutions with strictly positive components and impulses of a nonautonomous ratio-dependent predator-prey system. Sufficient criteria were obtained for the existence of strictly positive periodic solutions. The approach was based on a continuation theorem in the coincidence degree theory as well as some prior estimates.
2007, (1): 36-41.
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By using the concept of partial ordering of matrix, some new definitions of partial ordering were put forward, such as $\boldsymbol{A}\leqslant^{\{1\}}\boldsymbol{B}\Leftrightarrow \boldsymbol{A}\boldsymbol{A}\{1\}=\boldsymbol{B}\boldsymbol{A}\{1\},\boldsymbol{A}\{1\}\boldsymbol{A}=\boldsymbol{A}\{1\}\boldsymbol{B} $ and $\boldsymbol{A}\leqslant^{\{1,2\}}\boldsymbol{B}\Leftrightarrow \boldsymbol{A}\boldsymbol{A}\{1,2\}=\boldsymbol{B}\boldsymbol{A}\{1,2\},\boldsymbol{A}\{1,2\}\boldsymbol{A}=\boldsymbol{A}\{1,2\}\boldsymbol{B}$. Four situations were discussed in detail, according to which, sufficient and necessary conditions of the new partial ordering have been derived.
By using the concept of partial ordering of matrix, some new definitions of partial ordering were put forward, such as $\boldsymbol{A}\leqslant^{\{1\}}\boldsymbol{B}\Leftrightarrow \boldsymbol{A}\boldsymbol{A}\{1\}=\boldsymbol{B}\boldsymbol{A}\{1\},\boldsymbol{A}\{1\}\boldsymbol{A}=\boldsymbol{A}\{1\}\boldsymbol{B} $ and $\boldsymbol{A}\leqslant^{\{1,2\}}\boldsymbol{B}\Leftrightarrow \boldsymbol{A}\boldsymbol{A}\{1,2\}=\boldsymbol{B}\boldsymbol{A}\{1,2\},\boldsymbol{A}\{1,2\}\boldsymbol{A}=\boldsymbol{A}\{1,2\}\boldsymbol{B}$. Four situations were discussed in detail, according to which, sufficient and necessary conditions of the new partial ordering have been derived.
2007, (1): 42-46.
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The global robust stabilization problem for a class ofnonlinear uncertain two-time scale systems was studied. The robustcomposite feedback control for the whole systems was obtained byapplying the two-time scale design approach, and the upper stabilitybound of $\varepsilon $ was also given. Finally, examples of theapplication of the result were presented.
The global robust stabilization problem for a class ofnonlinear uncertain two-time scale systems was studied. The robustcomposite feedback control for the whole systems was obtained byapplying the two-time scale design approach, and the upper stabilitybound of $\varepsilon $ was also given. Finally, examples of theapplication of the result were presented.
2007, (1): 47-50.
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The asymptotic stability of nonlinear time-varying discrete-time systems was studied by using Lyapunov approach. If there exists time independent Lyapunov function V that is positively definite, and its difference is non-increased along the solutions of the systems, plus the additional condition imposed as the one of statements of the Barbashin-Krasovskii theorem, theconclusion of asymptotic stability will be obtained. In applications of Theorem 1 to the time-invariant and periodic systems respectively, the LaSalle theorem and Barbashin-Krasovskii theorem can be reobtained.
The asymptotic stability of nonlinear time-varying discrete-time systems was studied by using Lyapunov approach. If there exists time independent Lyapunov function V that is positively definite, and its difference is non-increased along the solutions of the systems, plus the additional condition imposed as the one of statements of the Barbashin-Krasovskii theorem, theconclusion of asymptotic stability will be obtained. In applications of Theorem 1 to the time-invariant and periodic systems respectively, the LaSalle theorem and Barbashin-Krasovskii theorem can be reobtained.
2007, (1): 51-55.
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For the total tardiness scheduling with precedence constraints, an approximation algorithm with polynomial complexity was presented bytransplanting the backward-shift algorithm of the case without precedence constraints. The new algorithm can get an approximation solution for the scheduling quickly.
For the total tardiness scheduling with precedence constraints, an approximation algorithm with polynomial complexity was presented bytransplanting the backward-shift algorithm of the case without precedence constraints. The new algorithm can get an approximation solution for the scheduling quickly.
2007, (1): 56-61.
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This paper investigated the choice number of some complete k-partite graphs, pointed out and corrected some mistakes of S. Gravier, H. Enomoto, et al.. The choice number of the complete k-partite graph K(4, 2, ..., 2) were determined, and also presented were a type of complete multi-partite graphs whose choice numbers are not equal to their chromatic numbers.
This paper investigated the choice number of some complete k-partite graphs, pointed out and corrected some mistakes of S. Gravier, H. Enomoto, et al.. The choice number of the complete k-partite graph K(4, 2, ..., 2) were determined, and also presented were a type of complete multi-partite graphs whose choice numbers are not equal to their chromatic numbers.
2007, (1): 62-64.
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This paper studied the lower bound for the number of triangles having the same color in any 2-edge-colored complete graph, and found the exact number of such triangles by means of adjacency matrix.
This paper studied the lower bound for the number of triangles having the same color in any 2-edge-colored complete graph, and found the exact number of such triangles by means of adjacency matrix.
2007, (1): 65-69.
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Linear regression model with elliptically symmetric errors and unknown dispersion matrix was discussed. For a given matrix $ \Sigma}_{0}$, when the real dispersion matrix varying within certain range, the GLSE $\hat{\beta}({\vec \Sigma}_{0}) = (\X'{\vec \Sigma}_{0}^{-1}\X)^{-1}\X'{\vec \Sigma}_{0}^{-1}y$ is the minimum risk estimator under a large class of loss functions, which implies the GLSE is a robust estimator with respect to dispersion matrix and loss functions.
Linear regression model with elliptically symmetric errors and unknown dispersion matrix was discussed. For a given matrix $ \Sigma}_{0}$, when the real dispersion matrix varying within certain range, the GLSE $\hat{\beta}({\vec \Sigma}_{0}) = (\X'{\vec \Sigma}_{0}^{-1}\X)^{-1}\X'{\vec \Sigma}_{0}^{-1}y$ is the minimum risk estimator under a large class of loss functions, which implies the GLSE is a robust estimator with respect to dispersion matrix and loss functions.
2007, (1): 70-77.
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Ruin problems in the ordinary renewal risk model with stochastic investment were examined. The asset price process of investment is denoted by $\{e^{R_t},\ t\geqslant 0\}$, where $R_t$ is assumed to be a L\'{e}vy process. By constructing a supermartingale associated with the ruin time of the surplus process with investment, an upper bound for ultimate ruin probability bymartingale approach was presented. The impact of inter-arrival times of claims on ruin probability was considered by numerical method.
Ruin problems in the ordinary renewal risk model with stochastic investment were examined. The asset price process of investment is denoted by $\{e^{R_t},\ t\geqslant 0\}$, where $R_t$ is assumed to be a L\'{e}vy process. By constructing a supermartingale associated with the ruin time of the surplus process with investment, an upper bound for ultimate ruin probability bymartingale approach was presented. The impact of inter-arrival times of claims on ruin probability was considered by numerical method.
2007, (1): 78-83.
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This paper designed a WYSWYG online formula input system based on MathML, in order to transmit and present the scientific formula in plain text on the network.
This paper designed a WYSWYG online formula input system based on MathML, in order to transmit and present the scientific formula in plain text on the network.
2007, (1): 84-90.
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The algorithm of fingerprint feature extraction using Gabor filterbank was proposed in order to overcome the drawback of traditional minutiae feature extraction. Through studying texture structure information of fingerprint ridges and applying Gabor filterbank to texture, a physical model of Gabor filtering was established. A quick and simple method of center point searching was presented, according to center point's position round grid feature area was located, filtering by eight directions of Gabor filterbank and feature extraction.The result of comparison experiment showed validity of Gaborbased.
The algorithm of fingerprint feature extraction using Gabor filterbank was proposed in order to overcome the drawback of traditional minutiae feature extraction. Through studying texture structure information of fingerprint ridges and applying Gabor filterbank to texture, a physical model of Gabor filtering was established. A quick and simple method of center point searching was presented, according to center point's position round grid feature area was located, filtering by eight directions of Gabor filterbank and feature extraction.The result of comparison experiment showed validity of Gaborbased.
2007, (1): 91-99.
Abstract:
Merchandise with certain lifespan and orderdiscount was studied. Its characters in orderinventorysale were analyzed. Based on the simulation principle of the discrete events system, a system simulation model was created, and the simulation software was developed. The inventory system was analyzed with simulation experiments. The model and the software supply retailers with an efficient tool for establishing orderinventorysale policy.
Merchandise with certain lifespan and orderdiscount was studied. Its characters in orderinventorysale were analyzed. Based on the simulation principle of the discrete events system, a system simulation model was created, and the simulation software was developed. The inventory system was analyzed with simulation experiments. The model and the software supply retailers with an efficient tool for establishing orderinventorysale policy.
2007, (1): 100-106.
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This paper analyzed some existing image watermarking algorithms using singular value decomposition(SVD) technique, and pointed out they have the problem of high error detection rate of original image and randomly chosen images. With the analysis of SVD's properties a new algorithm was proposed. Experiments showed the new proposed algorithm can distinguish the watermarked image from unwatemarked original image.It can also significantly decrease error detection rate of randomly chosen images. This algorithm has good robustness.
This paper analyzed some existing image watermarking algorithms using singular value decomposition(SVD) technique, and pointed out they have the problem of high error detection rate of original image and randomly chosen images. With the analysis of SVD's properties a new algorithm was proposed. Experiments showed the new proposed algorithm can distinguish the watermarked image from unwatemarked original image.It can also significantly decrease error detection rate of randomly chosen images. This algorithm has good robustness.
2007, (1): 107-112.
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Amorphous Fe73.5Cu1Nb3Si13.5B9 microwires were prepared by glasscoated melt spinning technique. Nanocrystalline samples were obtained by annealing the amorphous wires at 570 ℃.The diameter of the microwires varied between 16~50 μm.The relationship between giant magnetoimpedance effect and the metallic core diameter was investigated. The results showed that the GMI ratios first increase then decrease with the increase of metallic core diameter. The highest magnetoimpedance ratio of 251% is obtained in the nanocrystalline microwire with 30 μm in diameter.
Amorphous Fe73.5Cu1Nb3Si13.5B9 microwires were prepared by glasscoated melt spinning technique. Nanocrystalline samples were obtained by annealing the amorphous wires at 570 ℃.The diameter of the microwires varied between 16~50 μm.The relationship between giant magnetoimpedance effect and the metallic core diameter was investigated. The results showed that the GMI ratios first increase then decrease with the increase of metallic core diameter. The highest magnetoimpedance ratio of 251% is obtained in the nanocrystalline microwire with 30 μm in diameter.
2007, (1): 113-118.
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Mechanism of interface reaction and magnetic properties of Fe-TiN system attained by high energy ball milling were studied using Xray diffraction (XRD), Mssbauer spectroscopy and vibrating sample magnetometer(VSM). The results showed that during ball milling, a small amount of Fe atoms diffuse into the interface of TiN grains to form a paramagnetic interface phase TiN(Fe)and the diffusion of Fe atoms saturates with increasing milling time. Meanwhile, Ti and N atoms, as a result of the decomposition of fractional TiN, dissolve into the crystal lattices of Fe to form a ferromagnetic solid solution ofFe (Ti,N). The solid solution of Ti and N atoms make the saturation magnetization of powder samples rise first and then fall with the amount of Ti and N atoms increasing.
Mechanism of interface reaction and magnetic properties of Fe-TiN system attained by high energy ball milling were studied using Xray diffraction (XRD), Mssbauer spectroscopy and vibrating sample magnetometer(VSM). The results showed that during ball milling, a small amount of Fe atoms diffuse into the interface of TiN grains to form a paramagnetic interface phase TiN(Fe)and the diffusion of Fe atoms saturates with increasing milling time. Meanwhile, Ti and N atoms, as a result of the decomposition of fractional TiN, dissolve into the crystal lattices of Fe to form a ferromagnetic solid solution ofFe (Ti,N). The solid solution of Ti and N atoms make the saturation magnetization of powder samples rise first and then fall with the amount of Ti and N atoms increasing.
2007, (1): 119-126.
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This paper used the Half Fourier Transform to analyze various components of a nonstationary signal. By MATLAB simulation, a practical example, remote sensing a finite cylinder, was tested to verify the proposed algorithm. The result showed that in the higher SNR, the proposed algorithm can perfectly meet our expectation: to separate impulse like components from damped exponentials.
This paper used the Half Fourier Transform to analyze various components of a nonstationary signal. By MATLAB simulation, a practical example, remote sensing a finite cylinder, was tested to verify the proposed algorithm. The result showed that in the higher SNR, the proposed algorithm can perfectly meet our expectation: to separate impulse like components from damped exponentials.
2007, (1): 127-134.
Abstract:
The(Ni80Fe20/SiO2)n/Cu/(SiO2/Ni80Fe20)n composite multilayers were deposited onto glass substrates using RF magnetron sputtering equipment. The giant magneto impedance (GMI) effect was been investigated. The results show that the GMI effect enhanced, when the (Ni80Fe20/SiO2) bilayers structure repeated in the sample. At n=3, the maximum LMI ratio is 10.81%，while the maximum TMI ratios is 17.08%. And when n increases to 4 and 5, the MI ratios decrease slightly compared with the ratios at n=3. By the Xray diffraction spectrums and the hysteresis loops, the change of the samples′ crystallization structure, magnetism characteristic and GMI effect were studied, which were induced by the number of bilayers.
The(Ni80Fe20/SiO2)n/Cu/(SiO2/Ni80Fe20)n composite multilayers were deposited onto glass substrates using RF magnetron sputtering equipment. The giant magneto impedance (GMI) effect was been investigated. The results show that the GMI effect enhanced, when the (Ni80Fe20/SiO2) bilayers structure repeated in the sample. At n=3, the maximum LMI ratio is 10.81%，while the maximum TMI ratios is 17.08%. And when n increases to 4 and 5, the MI ratios decrease slightly compared with the ratios at n=3. By the Xray diffraction spectrums and the hysteresis loops, the change of the samples′ crystallization structure, magnetism characteristic and GMI effect were studied, which were induced by the number of bilayers.
2007, (1): 135-140.
Abstract:
This paper reported a novel method to prepare rutile TiO2 nanoparticles. When TiCl4 solution hydrolyzed, rutile TiO2 nanoparticles can be prepared at low temperature by adding a kind of organic additive into TiCl4 solution. XRD, FE-SEM and TG-DTA were used to analyze the influence of the amount of organic additives and the calcining temperature on the phase and particle size of prepared nanoparticles. It was found that the best additive amount is0.5 g/100 mL H2O, and the best calcining temperature is about 400 ℃. Being treated at the best condition, rutile TiO2 nanoparticles (40~50 nm) can be obtained.
This paper reported a novel method to prepare rutile TiO2 nanoparticles. When TiCl4 solution hydrolyzed, rutile TiO2 nanoparticles can be prepared at low temperature by adding a kind of organic additive into TiCl4 solution. XRD, FE-SEM and TG-DTA were used to analyze the influence of the amount of organic additives and the calcining temperature on the phase and particle size of prepared nanoparticles. It was found that the best additive amount is0.5 g/100 mL H2O, and the best calcining temperature is about 400 ℃. Being treated at the best condition, rutile TiO2 nanoparticles (40~50 nm) can be obtained.