Ultrathin InSb films on SiO2/Si substrates are prepared by radio frequency（RF） magnetron sputtering and rapid thermal annealing（RTA） at 300,400,and 500℃,respectively.X-ray diffraction（XRD） indicates that InSb f...Ultrathin InSb films on SiO2/Si substrates are prepared by radio frequency（RF） magnetron sputtering and rapid thermal annealing（RTA） at 300,400,and 500℃,respectively.X-ray diffraction（XRD） indicates that InSb film treated by RTA at 500℃,which is higher than its melting temperature（about 485℃）,shows a monocrystalline-like feature.A high-resolution transmission electron microscopy（HRTEM） micrograph shows that melt recrystallization of InSb film on SiO2/Si（111） substrate is along the（111） planes.The transmittances of InSb films decrease and the optical band gaps redshift from 0.24 eV to 0.19 eV with annealing temperature increasing from 300℃ to 500℃,which is indicated by Fourier transform infrared spectroscopy（FTIR） measurement.The observed changes demonstrate that RTA is a viable technique for improving characteristics of InSb films,especially the melt-recrystallized film treated by RTA at 500℃.展开更多
By considering a new discrete isospectral eigenvalue problem, a hierarchy of lattice soliton equations of rational type are derived. It is shown that each equation in the resulting hierarchy is integrable in Liouville...By considering a new discrete isospectral eigenvalue problem, a hierarchy of lattice soliton equations of rational type are derived. It is shown that each equation in the resulting hierarchy is integrable in Liouville sense and possessing bi-Hamiltonian structure. Two types of semi-direct sums of Lie algebras are proposed, by using of which a practicable way to construct discrete integrable couplings is introduced. As applications, two kinds of discrete integrable couplings of the resulting system are worked out.展开更多
In case handling, electronic evidence becomes more and more popular. In order to reduce the burden of judges＇ task to determine the integrity of chain of custody, even no technique experts on the spot, this paper sug...In case handling, electronic evidence becomes more and more popular. In order to reduce the burden of judges＇ task to determine the integrity of chain of custody, even no technique experts on the spot, this paper suggests a solution to solve this kind of problem.展开更多
We report the experimental method of angle-resolved in-plane light scattering for random surface parameter extraction.In the measurement of the scattered intensity profile at a certain angle of incidence,the perpendic...We report the experimental method of angle-resolved in-plane light scattering for random surface parameter extraction.In the measurement of the scattered intensity profile at a certain angle of incidence,the perpendicular component of wave vector remains constant,which is realized by controlling the movement of the detector along a specified circular arc segment.We use the central S-peak and the half-width of the diffused intensity profiles and their variations to obtain the roughness w,the lateral correlation lengthξand roughness exponent a of the rough surface sample.The measurement copes strictly with the theoretical analysis,and the inherent problem in previous in-plane light scattering experiment is overcome so that the changes of the perpendicular component of wave vector affect the half width a diffused intensity profile and the measurement accuracy.展开更多
Background and objective Low-density computed tomography(LDCT)improved early lung cancer diagnosis but introduces an excess of false-positive pulmonary nodules data.Hence,accurate diagnosis of early-stage lung cancer ...Background and objective Low-density computed tomography(LDCT)improved early lung cancer diagnosis but introduces an excess of false-positive pulmonary nodules data.Hence,accurate diagnosis of early-stage lung cancer remains challenging.The purpose of the study was to assess the feasibility of using circulating tumour cells(CTCs)to differentiate malignant from benign pulmonary nodules.Materials and methods 122 patients with suspected malignant pulmonary nodules detected on chest CT in preparation for surgery were prospectively recruited.Peripheral blood samples were collected before surgery,and CTCs were identified upon isolation by size of epithelial tumour cells and morphological analysis.Laser capture microdissection,MALBAC amplification,and whole-exome sequencing were performed on 8 samples.The diagnostic efficacy of CTCs counting,and the genomic variation profile of benign and malignant CTCs samples were analysed.Results Using 2.5 cells/5 m L as the cut-off value,the area under the receiver operating characteristic curve was of 0.651(95%confidence interval:0.538-0.764),with a sensitivity and specificity of 0.526 and 0.800,respectively,and positive and negative predictive values of 91.1%and 30.3%,respectively.Distinct sequence variations differences in DNA damage repair-related and driver genes were observed in benign and malignant samples.TP53 mutations were identified in CTCs of four malignant cases;in particular,g.7578115T>C,g.7578645C>T,and g.7579472G>C were exclusively detected in all four malignant samples.Conclusion CTCs play an ancillary role in the diagnosis of pulmonary nodules.TP53 mutations in CTCs might be used to identify benign and malignant pulmonary nodules.展开更多
Some properties of characteristic polynomials, eigenvalues, and eigenvectors of the Wilkinson matrices W2n＋1 and W2n＋1 are presented. It is proved that the eigenvalues of W2n＋1 just are the eigenvalues of its leadi...Some properties of characteristic polynomials, eigenvalues, and eigenvectors of the Wilkinson matrices W2n＋1 and W2n＋1 are presented. It is proved that the eigenvalues of W2n＋1 just are the eigenvalues of its leading principal submatrix Vn and a bordered matrix of Vn. Recurrence formula are given for the characteristic polynomial of W2＋n＋1 . The eigenvectors of W2＋n＋1 are proved to be symmetric or skew symmetric. For W2n＋1 , it is found that its eigenvalues are zero and the square roots of the eigenvalues of a bordered matrix of Vn2. And the eigenvectors of W2n＋1 , which the corresponding eigenvahies are opposite in pairs, have close relationship.展开更多
TiO_(2) films,showing superhydrophilic behavior,are prepared by electron beam evaporation.Atomic force microscopy and the contact angle measurement were performed to characterize the morphology and wetting behavior of...TiO_(2) films,showing superhydrophilic behavior,are prepared by electron beam evaporation.Atomic force microscopy and the contact angle measurement were performed to characterize the morphology and wetting behavior of the TiO_(2) films.Most studies attribute the wetting behavior of TiO_(2) surfaces to their physical characteristics rather than surface chemistry.These physical characteristics include surface morphology,roughness,and agglomerate size.We arrange these parameters in order of effectiveness.Surface morphologies are demonstrated to be the most important.TiO_(2) films with particular morphologies show superhydrophilic behavior without external stimuli,and these thin films also show stable anti-contamination properties during cyclical wetting and drying.展开更多
In this paper,a new approach of meander line technique for Printed Quadrifilar Helix Antenna(PQHA) is studied.Compared with other meander line techniques,this approach has lowered the axial height of antenna greatly a...In this paper,a new approach of meander line technique for Printed Quadrifilar Helix Antenna(PQHA) is studied.Compared with other meander line techniques,this approach has lowered the axial height of antenna greatly and improved the efficiency of model-building in simulation processing.We have focused on the analysis of radiation pattern,axial ratio,and design graph for the Meander line Printed Quadrifilar Helix Antenna(MPQHA).Finally,we have reduced successfully 67% size in geometry compared with traditional PQHA method,and obtained rather reasonable results.展开更多
In order to serve the local economic development,this study investigates the demand for local talents and analyzes the characteristics of the talent training in artificial intelligence in local colleges and universiti...In order to serve the local economic development,this study investigates the demand for local talents and analyzes the characteristics of the talent training in artificial intelligence in local colleges and universities.Subsequently,the talent training objectives of artificial intelligence specialty have been formulated,and a curriculum system that integrates the industry and education has been constructed in hope to continuously provide high-quality talents in artificial intelligence for the society.展开更多
In the context of engineering education accreditation,the teaching management mechanism should be student-centered and continuously improved.Therefore,the work of teaching secretaries and teaching supervisors also nee...In the context of engineering education accreditation,the teaching management mechanism should be student-centered and continuously improved.Therefore,the work of teaching secretaries and teaching supervisors also needs to be adjusted accordingly,in order to improve work efficiency and quality.This paper discusses the main contents and significance of engineering education accreditation,analyzes the relationship between teaching supervision,teaching secretary,and engineering education accreditation,applies the concept of engineering education accreditation to the work management of teaching secretary and teaching supervision,and proposes countermeasures to improve the work effect of teaching supervision and teaching secretary under the concept of engineering education accreditation.展开更多
This paper is mainly to deal with the problem of direction of arrival(DOA) estimations of multiple narrow-band sources impinging on a uniform linear array under impulsive noise environments. By modeling the impulsive ...This paper is mainly to deal with the problem of direction of arrival(DOA) estimations of multiple narrow-band sources impinging on a uniform linear array under impulsive noise environments. By modeling the impulsive noise as α-stable distribution, new methods which combine the sparse signal representation technique and fractional lower order statistics theory are proposed. In the new algorithms, the fractional lower order statistics vectors of the array output signal are sparsely represented on an overcomplete basis and the DOAs can be effectively estimated by searching the sparsest coefficients. To enhance the robustness performance of the proposed algorithms,the improved algorithms are advanced by eliminating the fractional lower order statistics of the noise from the fractional lower order statistics vector of the array output through a linear transformation. Simulation results have shown the effectiveness of the proposed methods for a wide range of highly impulsive environments.展开更多
The robustness of infrastructure networks has attracted great attention in recent years. Scholars have studied the robustness of complex networks against cascading failures from different aspects. In this paper, a new...The robustness of infrastructure networks has attracted great attention in recent years. Scholars have studied the robustness of complex networks against cascading failures from different aspects. In this paper, a new capacity allocation strategy is proposed to reduce cascading failures and improve network robustness without changing the network structure.Compared with the typical strategy proposed in Motter–Lai(ML) model, the new strategy can reduce the scale of cascading failure. The new strategy applied in scale-free network is more efficient. In addition, to reasonably evaluate the two strategies, we introduce contribution rate of unit capacity to network robustness as evaluation index. Results show that our new strategy works well, and it is more advantageous in the rational utilization of capacity in scale-free networks.Furthermore, we were surprised to find that the efficient utilization of capacity costs declined as costs rose above a certain threshold, which indicates that it is not wise to restrain cascading failures by increasing capacity costs indefinitely.展开更多
The coupled semi-discrete modified Korteweg-de Vries equation in （2＋1）-dimensions is proposed, it is shown that it, can be decomposed into two （1＋1）-dimensional differential-difference equations belonging to mKd...The coupled semi-discrete modified Korteweg-de Vries equation in （2＋1）-dimensions is proposed, it is shown that it, can be decomposed into two （1＋1）-dimensional differential-difference equations belonging to mKdV lattice hierarchy by considering a discrete isospeetral problem. A Darboux transformation is set up for the resulting （2＋1）- dimensional lattice soliton equation with the help of gauge transformations of Lax pairs. As an illustration by example, the soliton solutions of the mKdV lartice equation in （2＋1）-dimensions are explicitly given,展开更多
The typical model, which involves the measures： support, confidence, and interest, is often adapted to mining association rules. In the model, the related parameters are usually chosen by experience; consequently, th...The typical model, which involves the measures： support, confidence, and interest, is often adapted to mining association rules. In the model, the related parameters are usually chosen by experience; consequently, the number of useful rules is hard to estimate. If the number is too large, we cannot effectively extract the meaningful rules. This paper analyzes the meanings of the parameters and designs a variety of equations between the number of rules and the parameters by using regression method. Finally, we experimentally obtain a preferable regression equation. This paper uses multiple correlation coeficients to test the fitting efiects of the equations and uses significance test to verify whether the coeficients of parameters are significantly zero or not. The regression equation that has a larger multiple correlation coeficient will be chosen as the optimally fitted equation. With the selected optimal equation, we can predict the number of rules under the given parameters and further optimize the choice of the three parameters and determine their ranges of values.展开更多
Various lead-free ceramics have been investigated in search for new high-temperature dielectrics. In particular, Bi_4Ti_3O_（12） is a type of ferroelectric ceramics, which is supposed to replace leadcontaining cerami...Various lead-free ceramics have been investigated in search for new high-temperature dielectrics. In particular, Bi_4Ti_3O_（12） is a type of ferroelectric ceramics, which is supposed to replace leadcontaining ceramics for its outstanding dielectric properties in the near future. Ferroelectric ceramics of Bi_4Ti_3O_（12） made by conventional mixed oxide route have been studied by impedance spectroscopy in a wide range of temperature. X-ray diffraction patterns show that Bi_4Ti_3O_（12） ceramics are a single-phase of ferroelectric Bi-layered perovskite structure whether it is calcined at 800 ℃ or after sintering production. This study focused on the effect of the grain size on the electric properties of BIT ceramics. The BIT ceramics with different grain sizes were prepared at different sintering temperatures. Grain becomes coarser with the sintering temperature increasing by 50 ℃, relative permittivity and dielectric loss also change a lot. When sintered at 1 100 ℃, r values peak can reach 205.40 at a frequency of 100 k Hz, the minimum dielectric losses of four different frequencies make no difference, all close to 0.027. The values of Ea range from 0.52 to 0.68 e V. The dielectric properties of the sample sintered at 1 100 ℃ are relatively better than those of the other samples by analyzing the relationship of the grain, the internal stresses, the homogeneity and the dielectric properties. SEM can better explain the results of the dielectric spectrum at different sintering temperatures. The results show that Bi_4Ti_3O_（12） ceramics are a kind of dielectrics. Thus, Bi_4Ti_3O_（12） can be used in high-temperature capacitors and microwave ceramics.展开更多
Heterogeneous network consists of the pico cells overlaid over the macro cell coverage area in a wireless cellular network. The pico cells are deployed to increase the capacity of the homogeneous network by reusing th...Heterogeneous network consists of the pico cells overlaid over the macro cell coverage area in a wireless cellular network. The pico cells are deployed to increase the capacity of the homogeneous network by reusing the spectrum further. However, more users will tend to be associated to the macro cell due to the fact that the transmit power of the pico cell is low. In order to increase the number of users associated to the pico cell, range extension techniques like biased association are used. This will cause severe interference to cell edge users of the pico cell from the macro cell causing degradation in throughput performance in the cell range extension area. In this paper, interference mitigation using receiver processing along with different scheduling techniques is proposed to improve the throughput, average delay, and the packet delivery ratio performance of the system. The performance comparison of the round robin, proportional fair and modified largest weighted delay first (MLWDF) algorithm for resource allocation using interference suppressing receiver is done, and analyzed. It is shown that the MLWDF algorithm achieves the highest throughput with minimum average delay of packets with the best delivery ratio.展开更多
Monitoring the thickness changes of channel siltation is paramount in safeguarding navigation and guiding dredging, This paper presents a novel method for realizing the field monitoring of channel siltation in real ti...Monitoring the thickness changes of channel siltation is paramount in safeguarding navigation and guiding dredging, This paper presents a novel method for realizing the field monitoring of channel siltation in real time. The method is based on the bistatic scattering theory and concerned more with the receiving and processing of multipath signal at high-frequency and small grazing angle. By use of the multipath propagation structure of underwater acoustic channel, the method obtains the silt thickness by calculating the relative time delay of acoustic signals between the direct and the shortest bottom reflected paths. Bistatic transducer pairs are employed to transmit and receive the acoustic signals, and the GPS time synchronization technology is introduced to synchronize the transmitter and receiver, The WRELAX （Weighted Fourier transforul and RELAX） algorithm is used to obtain the high resolution estimation of muhipath time delay. To examine the feasibility of the presented method and the accuracy and precision of the developed system, a series of sea trials are conducted in the southwest coast area of Dalian City, north of the Yellow Sea. The experimental results are compared with that using high-resolution dual echo sounder HydroBoxTM, and the uncertainty is smaller than ＋ 0.06 m. Compared with the existing means for measuring the silt thickness, the present method is innovative, and the system is stable, efficient and provides a better real-time performance. It especially suits monitoring the narrow channel with rapid changes of siltation.展开更多
A semi-direct sum of two Lie algebras of four-by-four matrices is presented,and a discrete four-by-fourmatrix spectral problem is introduced.A hierarchy of discrete integrable coupling systems is derived.The obtainedi...A semi-direct sum of two Lie algebras of four-by-four matrices is presented,and a discrete four-by-fourmatrix spectral problem is introduced.A hierarchy of discrete integrable coupling systems is derived.The obtainedintegrable coupling systems are all written in their Hamiltonian forms by the discrete variational identity.Finally,we prove that the lattice equations in the obtained integrable coupling systems are all Liouville integrable discreteHamiltonian systems.展开更多
Cybercrimes have become an eye-catching social problem in not only China but also other countries of the world. Cybercrimes can be divided into two categories and different kinds of cybercrimes shall be treated differ...Cybercrimes have become an eye-catching social problem in not only China but also other countries of the world. Cybercrimes can be divided into two categories and different kinds of cybercrimes shall be treated differently. In this article, some typical cybercrimes are introduced in detail in order to set forth the characteristics of those cybercrimes. However, to defeat cybercrimes, joint efforts from countries all over the world shall be made.展开更多
基金Project supported by the Special Funds for State 11th Five-Year Basic Research Project of China (Grant No. 51318060207)
文摘Ultrathin InSb films on SiO2/Si substrates are prepared by radio frequency（RF） magnetron sputtering and rapid thermal annealing（RTA） at 300,400,and 500℃,respectively.X-ray diffraction（XRD） indicates that InSb film treated by RTA at 500℃,which is higher than its melting temperature（about 485℃）,shows a monocrystalline-like feature.A high-resolution transmission electron microscopy（HRTEM） micrograph shows that melt recrystallization of InSb film on SiO2/Si（111） substrate is along the（111） planes.The transmittances of InSb films decrease and the optical band gaps redshift from 0.24 eV to 0.19 eV with annealing temperature increasing from 300℃ to 500℃,which is indicated by Fourier transform infrared spectroscopy（FTIR） measurement.The observed changes demonstrate that RTA is a viable technique for improving characteristics of InSb films,especially the melt-recrystallized film treated by RTA at 500℃.
基金National Natural Science Foundation of China under Grant No.60572113the Natural Science Foundation of Shandong Province of China under Grant No.Q2006A04the Talents Foundation of Taishan College under Grant No.Y05-2-01
文摘By considering a new discrete isospectral eigenvalue problem, a hierarchy of lattice soliton equations of rational type are derived. It is shown that each equation in the resulting hierarchy is integrable in Liouville sense and possessing bi-Hamiltonian structure. Two types of semi-direct sums of Lie algebras are proposed, by using of which a practicable way to construct discrete integrable couplings is introduced. As applications, two kinds of discrete integrable couplings of the resulting system are worked out.
文摘In case handling, electronic evidence becomes more and more popular. In order to reduce the burden of judges＇ task to determine the integrity of chain of custody, even no technique experts on the spot, this paper suggests a solution to solve this kind of problem.
基金Supported by the National Natural Science Foundation of China(Grant No.10974122,10874105)the Shandong Distinguished Middle-aged and Young Scientist Encourage and Reward Foundation,China(Grant No.2007BS04031 and BS2009SF020)。
文摘We report the experimental method of angle-resolved in-plane light scattering for random surface parameter extraction.In the measurement of the scattered intensity profile at a certain angle of incidence,the perpendicular component of wave vector remains constant,which is realized by controlling the movement of the detector along a specified circular arc segment.We use the central S-peak and the half-width of the diffused intensity profiles and their variations to obtain the roughness w,the lateral correlation lengthξand roughness exponent a of the rough surface sample.The measurement copes strictly with the theoretical analysis,and the inherent problem in previous in-plane light scattering experiment is overcome so that the changes of the perpendicular component of wave vector affect the half width a diffused intensity profile and the measurement accuracy.
基金supported by the grant from China-Japan Friendship Hospital Talent Introduction Research Start-up Fund(to Guang ying ZHU)(No.2016-RC-4)。
文摘Background and objective Low-density computed tomography(LDCT)improved early lung cancer diagnosis but introduces an excess of false-positive pulmonary nodules data.Hence,accurate diagnosis of early-stage lung cancer remains challenging.The purpose of the study was to assess the feasibility of using circulating tumour cells(CTCs)to differentiate malignant from benign pulmonary nodules.Materials and methods 122 patients with suspected malignant pulmonary nodules detected on chest CT in preparation for surgery were prospectively recruited.Peripheral blood samples were collected before surgery,and CTCs were identified upon isolation by size of epithelial tumour cells and morphological analysis.Laser capture microdissection,MALBAC amplification,and whole-exome sequencing were performed on 8 samples.The diagnostic efficacy of CTCs counting,and the genomic variation profile of benign and malignant CTCs samples were analysed.Results Using 2.5 cells/5 m L as the cut-off value,the area under the receiver operating characteristic curve was of 0.651(95%confidence interval:0.538-0.764),with a sensitivity and specificity of 0.526 and 0.800,respectively,and positive and negative predictive values of 91.1%and 30.3%,respectively.Distinct sequence variations differences in DNA damage repair-related and driver genes were observed in benign and malignant samples.TP53 mutations were identified in CTCs of four malignant cases;in particular,g.7578115T>C,g.7578645C>T,and g.7579472G>C were exclusively detected in all four malignant samples.Conclusion CTCs play an ancillary role in the diagnosis of pulmonary nodules.TP53 mutations in CTCs might be used to identify benign and malignant pulmonary nodules.
基金The Fundamental Research Funds for the Central Universities, China (No.10D10908)
文摘Some properties of characteristic polynomials, eigenvalues, and eigenvectors of the Wilkinson matrices W2n＋1 and W2n＋1 are presented. It is proved that the eigenvalues of W2n＋1 just are the eigenvalues of its leading principal submatrix Vn and a bordered matrix of Vn. Recurrence formula are given for the characteristic polynomial of W2＋n＋1 . The eigenvectors of W2＋n＋1 are proved to be symmetric or skew symmetric. For W2n＋1 , it is found that its eigenvalues are zero and the square roots of the eigenvalues of a bordered matrix of Vn2. And the eigenvectors of W2n＋1 , which the corresponding eigenvahies are opposite in pairs, have close relationship.
基金Supported by the National Natural Science Foundation of China(60908021)the National Key Technologies R&D Program(2011BAF02B00)+2 种基金the National Science Instrument Important Project(2011YQ15004)Singapore National Research Foundation(CRP Award No NRF-G-CRP 2007-01)the Leading Academic Discipline Project of Shanghai Municipal Government(S30502).
文摘TiO_(2) films,showing superhydrophilic behavior,are prepared by electron beam evaporation.Atomic force microscopy and the contact angle measurement were performed to characterize the morphology and wetting behavior of the TiO_(2) films.Most studies attribute the wetting behavior of TiO_(2) surfaces to their physical characteristics rather than surface chemistry.These physical characteristics include surface morphology,roughness,and agglomerate size.We arrange these parameters in order of effectiveness.Surface morphologies are demonstrated to be the most important.TiO_(2) films with particular morphologies show superhydrophilic behavior without external stimuli,and these thin films also show stable anti-contamination properties during cyclical wetting and drying.
文摘In this paper,a new approach of meander line technique for Printed Quadrifilar Helix Antenna(PQHA) is studied.Compared with other meander line techniques,this approach has lowered the axial height of antenna greatly and improved the efficiency of model-building in simulation processing.We have focused on the analysis of radiation pattern,axial ratio,and design graph for the Meander line Printed Quadrifilar Helix Antenna(MPQHA).Finally,we have reduced successfully 67% size in geometry compared with traditional PQHA method,and obtained rather reasonable results.
文摘In order to serve the local economic development,this study investigates the demand for local talents and analyzes the characteristics of the talent training in artificial intelligence in local colleges and universities.Subsequently,the talent training objectives of artificial intelligence specialty have been formulated,and a curriculum system that integrates the industry and education has been constructed in hope to continuously provide high-quality talents in artificial intelligence for the society.
基金The funding of this paper comes from major project support for teaching reform research of Taishan University(JG202116)special project of education science planning in Tai’an+classroom teaching based on teaching reflection(TJK2202106ZX039)。
文摘In the context of engineering education accreditation,the teaching management mechanism should be student-centered and continuously improved.Therefore,the work of teaching secretaries and teaching supervisors also needs to be adjusted accordingly,in order to improve work efficiency and quality.This paper discusses the main contents and significance of engineering education accreditation,analyzes the relationship between teaching supervision,teaching secretary,and engineering education accreditation,applies the concept of engineering education accreditation to the work management of teaching secretary and teaching supervision,and proposes countermeasures to improve the work effect of teaching supervision and teaching secretary under the concept of engineering education accreditation.
基金supported in part by the National Natural Science Foundation of China(61301228,61371091)the Fundamental Research Funds for the Central Universities(3132014212)
文摘This paper is mainly to deal with the problem of direction of arrival(DOA) estimations of multiple narrow-band sources impinging on a uniform linear array under impulsive noise environments. By modeling the impulsive noise as α-stable distribution, new methods which combine the sparse signal representation technique and fractional lower order statistics theory are proposed. In the new algorithms, the fractional lower order statistics vectors of the array output signal are sparsely represented on an overcomplete basis and the DOAs can be effectively estimated by searching the sparsest coefficients. To enhance the robustness performance of the proposed algorithms,the improved algorithms are advanced by eliminating the fractional lower order statistics of the noise from the fractional lower order statistics vector of the array output through a linear transformation. Simulation results have shown the effectiveness of the proposed methods for a wide range of highly impulsive environments.
基金Supported by National Nature Science Foundation of China （61074068, 60774009, 61034007）, and the Research Fund for the Doc- toral Program of Chinese Higher Education （200804220028）
文摘The robustness of infrastructure networks has attracted great attention in recent years. Scholars have studied the robustness of complex networks against cascading failures from different aspects. In this paper, a new capacity allocation strategy is proposed to reduce cascading failures and improve network robustness without changing the network structure.Compared with the typical strategy proposed in Motter–Lai(ML) model, the new strategy can reduce the scale of cascading failure. The new strategy applied in scale-free network is more efficient. In addition, to reasonably evaluate the two strategies, we introduce contribution rate of unit capacity to network robustness as evaluation index. Results show that our new strategy works well, and it is more advantageous in the rational utilization of capacity in scale-free networks.Furthermore, we were surprised to find that the efficient utilization of capacity costs declined as costs rose above a certain threshold, which indicates that it is not wise to restrain cascading failures by increasing capacity costs indefinitely.
基金The roject partially supported by National Natural Science Foundation of China under Grant No. 60572113
文摘The coupled semi-discrete modified Korteweg-de Vries equation in （2＋1）-dimensions is proposed, it is shown that it, can be decomposed into two （1＋1）-dimensional differential-difference equations belonging to mKdV lattice hierarchy by considering a discrete isospeetral problem. A Darboux transformation is set up for the resulting （2＋1）- dimensional lattice soliton equation with the help of gauge transformations of Lax pairs. As an illustration by example, the soliton solutions of the mKdV lartice equation in （2＋1）-dimensions are explicitly given,
基金supported by the National Natural Science Foundation of China (No. J07240003, No. 60773084, No. 60603023)National Research Fund for the Doctoral Program of Higher Education of China (No. 20070151009)
文摘The typical model, which involves the measures： support, confidence, and interest, is often adapted to mining association rules. In the model, the related parameters are usually chosen by experience; consequently, the number of useful rules is hard to estimate. If the number is too large, we cannot effectively extract the meaningful rules. This paper analyzes the meanings of the parameters and designs a variety of equations between the number of rules and the parameters by using regression method. Finally, we experimentally obtain a preferable regression equation. This paper uses multiple correlation coeficients to test the fitting efiects of the equations and uses significance test to verify whether the coeficients of parameters are significantly zero or not. The regression equation that has a larger multiple correlation coeficient will be chosen as the optimally fitted equation. With the selected optimal equation, we can predict the number of rules under the given parameters and further optimize the choice of the three parameters and determine their ranges of values.
基金Funded by Hubei Provincial Department of Education(No.D20161006)
文摘Various lead-free ceramics have been investigated in search for new high-temperature dielectrics. In particular, Bi_4Ti_3O_（12） is a type of ferroelectric ceramics, which is supposed to replace leadcontaining ceramics for its outstanding dielectric properties in the near future. Ferroelectric ceramics of Bi_4Ti_3O_（12） made by conventional mixed oxide route have been studied by impedance spectroscopy in a wide range of temperature. X-ray diffraction patterns show that Bi_4Ti_3O_（12） ceramics are a single-phase of ferroelectric Bi-layered perovskite structure whether it is calcined at 800 ℃ or after sintering production. This study focused on the effect of the grain size on the electric properties of BIT ceramics. The BIT ceramics with different grain sizes were prepared at different sintering temperatures. Grain becomes coarser with the sintering temperature increasing by 50 ℃, relative permittivity and dielectric loss also change a lot. When sintered at 1 100 ℃, r values peak can reach 205.40 at a frequency of 100 k Hz, the minimum dielectric losses of four different frequencies make no difference, all close to 0.027. The values of Ea range from 0.52 to 0.68 e V. The dielectric properties of the sample sintered at 1 100 ℃ are relatively better than those of the other samples by analyzing the relationship of the grain, the internal stresses, the homogeneity and the dielectric properties. SEM can better explain the results of the dielectric spectrum at different sintering temperatures. The results show that Bi_4Ti_3O_（12） ceramics are a kind of dielectrics. Thus, Bi_4Ti_3O_（12） can be used in high-temperature capacitors and microwave ceramics.
文摘Heterogeneous network consists of the pico cells overlaid over the macro cell coverage area in a wireless cellular network. The pico cells are deployed to increase the capacity of the homogeneous network by reusing the spectrum further. However, more users will tend to be associated to the macro cell due to the fact that the transmit power of the pico cell is low. In order to increase the number of users associated to the pico cell, range extension techniques like biased association are used. This will cause severe interference to cell edge users of the pico cell from the macro cell causing degradation in throughput performance in the cell range extension area. In this paper, interference mitigation using receiver processing along with different scheduling techniques is proposed to improve the throughput, average delay, and the packet delivery ratio performance of the system. The performance comparison of the round robin, proportional fair and modified largest weighted delay first (MLWDF) algorithm for resource allocation using interference suppressing receiver is done, and analyzed. It is shown that the MLWDF algorithm achieves the highest throughput with minimum average delay of packets with the best delivery ratio.
基金supported by the National Key Technology Research and Development Program of China(863 Program, Grant No.2009BAG18B03)
文摘Monitoring the thickness changes of channel siltation is paramount in safeguarding navigation and guiding dredging, This paper presents a novel method for realizing the field monitoring of channel siltation in real time. The method is based on the bistatic scattering theory and concerned more with the receiving and processing of multipath signal at high-frequency and small grazing angle. By use of the multipath propagation structure of underwater acoustic channel, the method obtains the silt thickness by calculating the relative time delay of acoustic signals between the direct and the shortest bottom reflected paths. Bistatic transducer pairs are employed to transmit and receive the acoustic signals, and the GPS time synchronization technology is introduced to synchronize the transmitter and receiver, The WRELAX （Weighted Fourier transforul and RELAX） algorithm is used to obtain the high resolution estimation of muhipath time delay. To examine the feasibility of the presented method and the accuracy and precision of the developed system, a series of sea trials are conducted in the southwest coast area of Dalian City, north of the Yellow Sea. The experimental results are compared with that using high-resolution dual echo sounder HydroBoxTM, and the uncertainty is smaller than ＋ 0.06 m. Compared with the existing means for measuring the silt thickness, the present method is innovative, and the system is stable, efficient and provides a better real-time performance. It especially suits monitoring the narrow channel with rapid changes of siltation.
基金the Natural Science Foundation of Shandong Province under Grant No.Q2006A04
文摘A semi-direct sum of two Lie algebras of four-by-four matrices is presented,and a discrete four-by-fourmatrix spectral problem is introduced.A hierarchy of discrete integrable coupling systems is derived.The obtainedintegrable coupling systems are all written in their Hamiltonian forms by the discrete variational identity.Finally,we prove that the lattice equations in the obtained integrable coupling systems are all Liouville integrable discreteHamiltonian systems.
基金This work was supported by National Social Science Foundation of China （No. 06BFX051） and Judicial Expertise Construction Project of 5th Key Discipline of Shanghai Education Committee （No. J51102）.
文摘Cybercrimes have become an eye-catching social problem in not only China but also other countries of the world. Cybercrimes can be divided into two categories and different kinds of cybercrimes shall be treated differently. In this article, some typical cybercrimes are introduced in detail in order to set forth the characteristics of those cybercrimes. However, to defeat cybercrimes, joint efforts from countries all over the world shall be made.
