Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4))...Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4)),and their interaction with distinct irreducible polynomials.The primary aim is to enhance watermarking techniques for achieving imperceptibility,robustness,and efficient execution time.The research employs scene selection and adaptive thresholding techniques to streamline the watermarking process.Scene selection is used strategically to embed watermarks in the most vital frames of the video,while adaptive thresholding methods ensure that the watermarking process adheres to imperceptibility criteria,maintaining the video's visual quality.Concurrently,careful consideration is given to execution time,crucial in real-world scenarios,to balance efficiency and efficacy.The Peak Signal-to-Noise Ratio(PSNR)serves as a pivotal metric to gauge the watermark's imperceptibility and video quality.The study explores various irreducible polynomials,navigating the trade-offs between computational efficiency and watermark imperceptibility.In parallel,the study pays careful attention to the execution time,a paramount consideration in real-world scenarios,to strike a balance between efficiency and efficacy.This comprehensive analysis provides valuable insights into the interplay of GF multiplication tables,diverse irreducible polynomials,scene selection,adaptive thresholding,imperceptibility,and execution time.The evaluation of the proposed algorithm's robustness was conducted using PSNR and NC metrics,and it was subjected to assessment under the impact of five distinct attack scenarios.These findings contribute to the development of watermarking strategies that balance imperceptibility,robustness,and processing efficiency,enhancing the field's practicality and effectiveness.展开更多
Toeplitz matrix-vector multiplication is widely used in various fields,including optimal control,systolic finite field multipliers,multidimensional convolution,etc.In this paper,we first present a non-asymptotic quant...Toeplitz matrix-vector multiplication is widely used in various fields,including optimal control,systolic finite field multipliers,multidimensional convolution,etc.In this paper,we first present a non-asymptotic quantum algorithm for Toeplitz matrix-vector multiplication with time complexity O(κpolylogn),whereκand 2n are the condition number and the dimension of the circulant matrix extended from the Toeplitz matrix,respectively.For the case with an unknown generating function,we also give a corresponding non-asymptotic quantum version that eliminates the dependency on the L_(1)-normρof the displacement of the structured matrices.Due to the good use of the special properties of Toeplitz matrices,the proposed quantum algorithms are sufficiently accurate and efficient compared to the existing quantum algorithms under certain circumstances.展开更多
The avalanche multiplication principle of electron multiplication CCD (EMCCD) was discussed on the basis of single type of carrier, and the multiplication model was built by using a classic piecewise ionization rate m...The avalanche multiplication principle of electron multiplication CCD (EMCCD) was discussed on the basis of single type of carrier, and the multiplication model was built by using a classic piecewise ionization rate model and avalanche multiplication integral formula. Wolff's ionization rate model was selected according to the structure and the multiplication gate amplitude of the actual devices. Compared the theoretical result with the multiplication curve of the actual device, it was found that only enough fringing field strength and multiplication area length could lead to adequate signal charge multiplication. The relationship between the multiplication gate amplitude and the total gain of the cascaded boosting EMCCD can be conveniently determined by using this model.展开更多
This article is devoted to characterizing the boundedness and compactness of multiplication operators from Hardy spaces to weigh ted Bergman spaces in the unit ball of C^n.
With the rhizomes obtained from the germination of Cymbidium sinense × Cymbidium goeringii seeds as a material,the effects of different basic media and different plant growth regulators on the multiplication and ...With the rhizomes obtained from the germination of Cymbidium sinense × Cymbidium goeringii seeds as a material,the effects of different basic media and different plant growth regulators on the multiplication and differentiation of rhizomes and rooting and transplanting of seedlings were investigated. The results showed that the basal medium more suitable for the multiplication and differentiation of rhizomes was 1/2 MS; the medium more suitable for the multiplication and differentiation of rhizomes of the hybrid orchid was 1/2 MS + 6-BA 2. 0 mg/L + KT 0. 5 mg/L + NAA 0. 05 mg/L; the medium more suitable for the rooting of the hybrid orchid was 1/2 MS + IBA 0. 5 mg/L; and after training of seedlings,transplanting was performed onto moss,and after 25 d,the survival rate was 95. 6%.展开更多
A special constant deflection device for TEM has been designed and then the dislocation configuration change ahead of a loaded crack tip after corrosion or anodic dissolution for some time but before the initiation of...A special constant deflection device for TEM has been designed and then the dislocation configuration change ahead of a loaded crack tip after corrosion or anodic dissolution for some time but before the initiation of SCC can be observed in TEM. The results showed that anodic dissolution during SCC of a type 310 stainless steel in deionized water could promote dislocation emission,multiplication and motion before the initiation of SCC.展开更多
As one of the most essential and important operations in linear algebra, the performance prediction of sparse matrix-vector multiplication (SpMV) on GPUs has got more and more attention in recent years. In 2012, Guo a...As one of the most essential and important operations in linear algebra, the performance prediction of sparse matrix-vector multiplication (SpMV) on GPUs has got more and more attention in recent years. In 2012, Guo and Wang put forward a new idea to predict the performance of SpMV on GPUs. However, they didn’t consider the matrix structure completely, so the execution time predicted by their model tends to be inaccurate for general sparse matrix. To address this problem, we proposed two new similar models, which take into account the structure of the matrices and make the performance prediction model more accurate. In addition, we predict the execution time of SpMV for CSR-V, CSR-S, ELL and JAD sparse matrix storage formats by the new models on the CUDA platform. Our experimental results show that the accuracy of prediction by our models is 1.69 times better than Guo and Wang’s model on average for most general matrices.展开更多
A fast algorithm is proposed for recursively computing the DFTs of prime length. Only (N-1) / 2 real multiplications are required to compute all N frequency components in terms of permuting the input data. The multipl...A fast algorithm is proposed for recursively computing the DFTs of prime length. Only (N-1) / 2 real multiplications are required to compute all N frequency components in terms of permuting the input data. The multiplication in recursive computation is replaced by shifting. Complexity of the algorithm is studied. A factor η is introduced and presented. When the ratio of multiplier’s period Tm to adder’s period Ta is greater than the factor η (i.e.Tm / Ta 】η), the new algorithm is faster than FFT. The necessary condition and error of the algorithm are studied. The signal-to-noise ratio for different length N is presented. A high accuracy scheme is proposed for improving the SNR about 20 -30dB.展开更多
In this paper, we build on the concept of equivalent fundamental-mode source to propose using delayed neutrons as a neutron source in multiplication experiments to acquire the effective multiplication factor keffof su...In this paper, we build on the concept of equivalent fundamental-mode source to propose using delayed neutrons as a neutron source in multiplication experiments to acquire the effective multiplication factor keffof subcritical systems, which is difficult to acquire directly from conventional neutron source multiplication method. We analyzed the difference between a fundamental-mode fission source and delayed neutron source,then adopted a factor to convert delayed neutron distribution to an equivalent fundamental-mode source distribution, and employed Monte Carlo code to acquire this factor.The delayed neutron multiplication measurement method was established for the first time, and corresponding experiments were conducted in subcritical systems. The multiplication of delayed neutrons was measured based on Chinese Fast Burst Reactor-Ⅱ(CFBR-Ⅱ) at subcritical states, and keffwas acquired from delayed neutron multiplication successfully(0.9921 and 0.9969, respectively).The relative difference between k_(eff)obtained by the new method and previous values acquired by the positive period method is less than 1% for these two studied cases.展开更多
It is well known that Ⅲ-nitride semiconductors can generate the magnitude of MV/cm polarization electric field which is comparable with their ionization electric fields. To take full advantage of the polarization ele...It is well known that Ⅲ-nitride semiconductors can generate the magnitude of MV/cm polarization electric field which is comparable with their ionization electric fields. To take full advantage of the polarization electric field, we design an N-face AlGaN solar-blind avalanche photodiode(APD) with an Al_(0.45)Ga_(0.55)N/Al_(0.3)Ga_(0.7)N heterostructure as separate absorption and multiplication(SAM) regions. The simulation results show that the N-face APDs are more beneficial to improving the avalanche gain and reducing the avalanche breakdown voltage compared with the Ga-face APDs due to the effect of the polarization electric field. Furthermore, the Al_(0.45)Ga_(0.55)N/Al_(0.3)Ga_(0.7)N heterostructure SAM regions used in APDs instead of homogeneous Al_(0.45)Ga_(0.55)N SAM structure can increase significantly avalanche gain because of the increased hole ionization coefficient by using the relatively low Al-content AlGaN in the multiplication region. Meanwhile, a quarter-wave AlGaN/AIN distributed Bragg reflector structure at the bottom of the device is designed to remain a solar-blind characteristic of the heterostructure SAM-APDs.展开更多
A new method of fringe multiplication is presented in this paper.The method is simpleand applicable.Only one polarizer and one quarter-wave plate are adopted to get fringemultiplication by reflection.
Electro dislocation multiplication and strain effect were investigated. TEM observation showed that when statically held for 15 min, the microstructure of dislocation cell in the specimens without current pulse turned...Electro dislocation multiplication and strain effect were investigated. TEM observation showed that when statically held for 15 min, the microstructure of dislocation cell in the specimens without current pulse turned to subgrains with few dislocations in cold rolled state, but when current pulse charged, there were a lot of dislocations although a more rapid recrystallization occurred concurrently; when deformed, the interior dislocations in the specimens without current pulse were annihilated due to dynamic recrystallization, but were not decreased in the current pulse charged specimens in dynamic recrystallization, instead increased. It is indicated that “electron wind” force created by current pulse produced a shear stress for dislocation slip, and caused a dislocation multiplication in static holding of 2091 Al Li alloy; when strain exerted, an additional shear stress was provided to increase the effect of current pulse on dislocation multiplication.展开更多
This research aims to improve the forecasting precision of electric quantity. It is discovered that the total electricity consumption considerably increased during the Spring Festival by the analysis of the electric q...This research aims to improve the forecasting precision of electric quantity. It is discovered that the total electricity consumption considerably increased during the Spring Festival by the analysis of the electric quantity time series from 2002 to 2007 in Shandong province. The festival factor is ascertained to be one of the important seasonal factors affecting the electric quantity fluctuations, and the multiplication model for forecasting is improved by introducing corresponding variables and parameters. The computational results indicate that the average relative error of the new model decreases from 4.31% to 1.93% and the maximum relative error from 14.05% to 6.52% compared with those of the model when the festival factor is not considered. It shows that introducing the festival factor into the multiplication model for electric quantity forecasting evidently improves the precision.展开更多
Matrix multiplication plays a pivotal role in the symmetric cipher algorithms, but it is one of the most complex and time consuming units, its performance directly affects the efficiency of cipher algorithms. Combined...Matrix multiplication plays a pivotal role in the symmetric cipher algorithms, but it is one of the most complex and time consuming units, its performance directly affects the efficiency of cipher algorithms. Combined with the characteristics of VLIW processor and matrix multiplication of symmetric cipher algorithms, this paper extracted the reconfigurable elements and analyzed the principle of matrix multiplication, then designed the reconfigurable architecture of matrix multiplication of VLIW processor further, at last we put forward single instructions for matrix multiplication between 4×1 and 4×4 matrix or two 4×4 matrix over GF(2~8), through the instructions extension, the instructions could support larger dimension operations. The experiment shows that the instructions we designed supports different dimensions matrix multiplication and improves the processing speed of multiplication greatly.展开更多
‘Candidatus Liberibacter asiaticus(CLas)’,which causes citrus Huanglongbing(HLB)disease,has not been successfully cultured in vitro to date.Here,a rapid multiplication system for CLas was established through in vitr...‘Candidatus Liberibacter asiaticus(CLas)’,which causes citrus Huanglongbing(HLB)disease,has not been successfully cultured in vitro to date.Here,a rapid multiplication system for CLas was established through in vitro regeneration of axillary buds from CLas-infected‘Changyecheng’sweet orange(Citrus sinensis Osbeck).Stem segments with a single axillary bud were cultured in vitro to allow CLas to multiply in the regenerating axillary buds.A high CLas titer was detected in the regenerated shoots on an optimized medium at 30 days after germination(DAG).This titer was 28.2-fold higher than in the midribs from CLas-infected trees growing in the greenhouse.To minimize contamination during in vitro regeneration,CLas-infected axillary buds were micrografted onto seedlings of‘Changyecheng’sweet orange and cultured in a liquid medium.In this culture,the titers of CLas in regenerated shoots rapidly increased from 7.5×10^(4)to 1.4×10^(8)cellsμg^(-1)of citrus DNA during the first 40 DAG.The percentages of shoots with>1×10^(8)CLas cellsμg^(-1)DNA were 30 and 40%at 30 and 40 DAG,respectively.Direct tissue blot immunoassay(DTBIA)indicated that the distribution of CLas was much more uniform in regenerated plantlets than in CLas-infected trees growing in the greenhouse.The disease symptoms in the plantlets were die-back,stunted growth,leaf necrosis/yellowing,and defoliation.The death rate of the plantlets was 82.0%at 60 DAG.Our results show that CLas can effectively multiply in citrus plantlests in vitro.This method will be useful for studying plant-HLB interactions and for rapid screening of therapeutic compounds against CLas in citrus.展开更多
This paper exploits coding to speed up computation offloading in a multi-server mobile edge computing(MEC)network with straggling servers and channel fading.The specific task we consider is to compute the product betw...This paper exploits coding to speed up computation offloading in a multi-server mobile edge computing(MEC)network with straggling servers and channel fading.The specific task we consider is to compute the product between a user-generated input data matrix and a large-scale model matrix that is stored distributively across the multiple edge nodes.The key idea of coding is to introduce computation redundancy to improve robustness against straggling servers and to create communication redundancy to improve reliability against channel fading.We utilize the hybrid design of maximum distance separable(MDS)coding and repetition coding.Based on the hybrid coding scheme,we conduct theoretical analysis on the average task uploading time,average edge computing time,and average output downloading time,respectively and then obtain the end-to-end task execution time.Numerical results demonstrate that when the task uploading phase or the edge computing phase is the performance bottleneck,the hybrid coding reduces to MDS coding;when the downlink transmission is the bottleneck,the hybrid coding reduces to repetition coding.The hybrid coding also outperforms the entangled polynomial coding that causes higher uplink and downlink communication loads.展开更多
Based on the precise integration method(PIM), a coupling technique of the high order multiplication perturbation method(HOMPM) and the reduction method is proposed to solve variable coefcient singularly perturbed two-...Based on the precise integration method(PIM), a coupling technique of the high order multiplication perturbation method(HOMPM) and the reduction method is proposed to solve variable coefcient singularly perturbed two-point boundary value problems(TPBVPs) with one boundary layer. First, the inhomogeneous ordinary diferential equations(ODEs) are transformed into the homogeneous ODEs by variable coefcient dimensional expansion. Then, the whole interval is divided evenly, and the transfer matrix in each sub-interval is worked out through the HOMPM. Finally, a group of algebraic equations are given based on the relationship between the neighboring sub-intervals, which are solved by the reduction method. Numerical results show that the present method is highly efcient.展开更多
In this paper, a yield model of polycrystalline metal based on thenonlinear irreversible multiplication is proposed, from which the kinetic yield equationsand the yield stress formulas can be deduced. Some yield pheno...In this paper, a yield model of polycrystalline metal based on thenonlinear irreversible multiplication is proposed, from which the kinetic yield equationsand the yield stress formulas can be deduced. Some yield phenomena and experimentalresults can be explained reasonably.展开更多
Several algorithms based on homogeneous polynomials for multiplication of large integers are described in the paper. The homogeneity of polynomials provides several simplifications: reduction of system of equations an...Several algorithms based on homogeneous polynomials for multiplication of large integers are described in the paper. The homogeneity of polynomials provides several simplifications: reduction of system of equations and elimination of necessity to evaluate polynomials in points with larger coordinates. It is demonstrated that a two-stage implementation of the proposed and Toom-Cook algorithms asymptotically require twice as many standard multiplications than their direct implementation. A multistage implementation of these algorithms is also less efficient than their direct implementation. Although the proposed algorithms as well as the corresponding Toom-Cook algorithms require numerous algebraic additions, the Generalized Horner rule for evaluation of homogeneous polynomials, provided in the paper, decrease this number twice.展开更多
Taro (Colocasia esculenta) and tannia (Xanthosoma sagittifolium) are commonly referred to as cocoyam in Nigeria. They are cherished for their rich taste, nutritional and medicinal properties. Traditionally, cocoyams a...Taro (Colocasia esculenta) and tannia (Xanthosoma sagittifolium) are commonly referred to as cocoyam in Nigeria. They are cherished for their rich taste, nutritional and medicinal properties. Traditionally, cocoyams are vegetatively propagated from tuber fragments, a practice that encourages pathogen distribution. For rapid multiplication and production of quality planting materials, tissue culture technology offers promising alternative compared to the traditional production methods. In this study different concentrations of ripped sweet orange (Citrus sinensis) juice were screened for regeneration and multiplication of 2 months old in vitro cocoyam shoot explants. Among the concentrations, maximum numbers of roots (37 ± 5) were observed in Murashige and Skoog (MS) medium supplemented with 10% orange juice after 8 weeks in culture compared to 16 ± 4 (roots) observed in the control medium. On shoot multiplicity, 16 ± 3 shoots were induced in the control medium in contrast to 12 ± 0.8 shoots in the MS medium supplemented with 10% orange juice after 8 weeks of culture. Higher concentrations (25% and 35%) of the orange juice supplemented medium resulted in concomitant inhibition of all the growth parameters. The study successfully established that ripped orange juice could substitute the use of conventional growth hormones cytokinins (BAP) and auxins (NAA) in in vitro regeneration and rapid multiplication of cocoyam shoot explants.展开更多
文摘Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4)),and their interaction with distinct irreducible polynomials.The primary aim is to enhance watermarking techniques for achieving imperceptibility,robustness,and efficient execution time.The research employs scene selection and adaptive thresholding techniques to streamline the watermarking process.Scene selection is used strategically to embed watermarks in the most vital frames of the video,while adaptive thresholding methods ensure that the watermarking process adheres to imperceptibility criteria,maintaining the video's visual quality.Concurrently,careful consideration is given to execution time,crucial in real-world scenarios,to balance efficiency and efficacy.The Peak Signal-to-Noise Ratio(PSNR)serves as a pivotal metric to gauge the watermark's imperceptibility and video quality.The study explores various irreducible polynomials,navigating the trade-offs between computational efficiency and watermark imperceptibility.In parallel,the study pays careful attention to the execution time,a paramount consideration in real-world scenarios,to strike a balance between efficiency and efficacy.This comprehensive analysis provides valuable insights into the interplay of GF multiplication tables,diverse irreducible polynomials,scene selection,adaptive thresholding,imperceptibility,and execution time.The evaluation of the proposed algorithm's robustness was conducted using PSNR and NC metrics,and it was subjected to assessment under the impact of five distinct attack scenarios.These findings contribute to the development of watermarking strategies that balance imperceptibility,robustness,and processing efficiency,enhancing the field's practicality and effectiveness.
基金supported by the National Natural Science Foundation of China(Grant Nos.62071015 and 62171264)。
文摘Toeplitz matrix-vector multiplication is widely used in various fields,including optimal control,systolic finite field multipliers,multidimensional convolution,etc.In this paper,we first present a non-asymptotic quantum algorithm for Toeplitz matrix-vector multiplication with time complexity O(κpolylogn),whereκand 2n are the condition number and the dimension of the circulant matrix extended from the Toeplitz matrix,respectively.For the case with an unknown generating function,we also give a corresponding non-asymptotic quantum version that eliminates the dependency on the L_(1)-normρof the displacement of the structured matrices.Due to the good use of the special properties of Toeplitz matrices,the proposed quantum algorithms are sufficiently accurate and efficient compared to the existing quantum algorithms under certain circumstances.
文摘The avalanche multiplication principle of electron multiplication CCD (EMCCD) was discussed on the basis of single type of carrier, and the multiplication model was built by using a classic piecewise ionization rate model and avalanche multiplication integral formula. Wolff's ionization rate model was selected according to the structure and the multiplication gate amplitude of the actual devices. Compared the theoretical result with the multiplication curve of the actual device, it was found that only enough fringing field strength and multiplication area length could lead to adequate signal charge multiplication. The relationship between the multiplication gate amplitude and the total gain of the cascaded boosting EMCCD can be conveniently determined by using this model.
基金Supported by the National Natural Science Foundation of China(11601400 and 11771441)the Fundamental Research Funds for the Central Universities(2017IB012 and 2017IVB064)
文摘This article is devoted to characterizing the boundedness and compactness of multiplication operators from Hardy spaces to weigh ted Bergman spaces in the unit ball of C^n.
基金Supported by Technical Research and Development and Demonstration Promotion Fund of Beijing Vocational College of Agriculture(XY-YF-13-05)
文摘With the rhizomes obtained from the germination of Cymbidium sinense × Cymbidium goeringii seeds as a material,the effects of different basic media and different plant growth regulators on the multiplication and differentiation of rhizomes and rooting and transplanting of seedlings were investigated. The results showed that the basal medium more suitable for the multiplication and differentiation of rhizomes was 1/2 MS; the medium more suitable for the multiplication and differentiation of rhizomes of the hybrid orchid was 1/2 MS + 6-BA 2. 0 mg/L + KT 0. 5 mg/L + NAA 0. 05 mg/L; the medium more suitable for the rooting of the hybrid orchid was 1/2 MS + IBA 0. 5 mg/L; and after training of seedlings,transplanting was performed onto moss,and after 25 d,the survival rate was 95. 6%.
文摘A special constant deflection device for TEM has been designed and then the dislocation configuration change ahead of a loaded crack tip after corrosion or anodic dissolution for some time but before the initiation of SCC can be observed in TEM. The results showed that anodic dissolution during SCC of a type 310 stainless steel in deionized water could promote dislocation emission,multiplication and motion before the initiation of SCC.
文摘As one of the most essential and important operations in linear algebra, the performance prediction of sparse matrix-vector multiplication (SpMV) on GPUs has got more and more attention in recent years. In 2012, Guo and Wang put forward a new idea to predict the performance of SpMV on GPUs. However, they didn’t consider the matrix structure completely, so the execution time predicted by their model tends to be inaccurate for general sparse matrix. To address this problem, we proposed two new similar models, which take into account the structure of the matrices and make the performance prediction model more accurate. In addition, we predict the execution time of SpMV for CSR-V, CSR-S, ELL and JAD sparse matrix storage formats by the new models on the CUDA platform. Our experimental results show that the accuracy of prediction by our models is 1.69 times better than Guo and Wang’s model on average for most general matrices.
文摘A fast algorithm is proposed for recursively computing the DFTs of prime length. Only (N-1) / 2 real multiplications are required to compute all N frequency components in terms of permuting the input data. The multiplication in recursive computation is replaced by shifting. Complexity of the algorithm is studied. A factor η is introduced and presented. When the ratio of multiplier’s period Tm to adder’s period Ta is greater than the factor η (i.e.Tm / Ta 】η), the new algorithm is faster than FFT. The necessary condition and error of the algorithm are studied. The signal-to-noise ratio for different length N is presented. A high accuracy scheme is proposed for improving the SNR about 20 -30dB.
基金supported by the National Natural Science Foundation of China(Nos.11175164 and 91326109)
文摘In this paper, we build on the concept of equivalent fundamental-mode source to propose using delayed neutrons as a neutron source in multiplication experiments to acquire the effective multiplication factor keffof subcritical systems, which is difficult to acquire directly from conventional neutron source multiplication method. We analyzed the difference between a fundamental-mode fission source and delayed neutron source,then adopted a factor to convert delayed neutron distribution to an equivalent fundamental-mode source distribution, and employed Monte Carlo code to acquire this factor.The delayed neutron multiplication measurement method was established for the first time, and corresponding experiments were conducted in subcritical systems. The multiplication of delayed neutrons was measured based on Chinese Fast Burst Reactor-Ⅱ(CFBR-Ⅱ) at subcritical states, and keffwas acquired from delayed neutron multiplication successfully(0.9921 and 0.9969, respectively).The relative difference between k_(eff)obtained by the new method and previous values acquired by the positive period method is less than 1% for these two studied cases.
基金Supported by the State Key Project of Research and Development Plan of China under Grant No 2016YFB0400903the National Natural Science Foundation of China under Grant Nos 61634002,61274075 and 61474060+2 种基金the Key Project of Jiangsu Province under Grant No BE2016174the Anhui University Natural Science Research Project under Grant No KJ2015A153the Open Fund of State KeyLab of Optical Technologies on Nano-fabrication and Micro-engineering
文摘It is well known that Ⅲ-nitride semiconductors can generate the magnitude of MV/cm polarization electric field which is comparable with their ionization electric fields. To take full advantage of the polarization electric field, we design an N-face AlGaN solar-blind avalanche photodiode(APD) with an Al_(0.45)Ga_(0.55)N/Al_(0.3)Ga_(0.7)N heterostructure as separate absorption and multiplication(SAM) regions. The simulation results show that the N-face APDs are more beneficial to improving the avalanche gain and reducing the avalanche breakdown voltage compared with the Ga-face APDs due to the effect of the polarization electric field. Furthermore, the Al_(0.45)Ga_(0.55)N/Al_(0.3)Ga_(0.7)N heterostructure SAM regions used in APDs instead of homogeneous Al_(0.45)Ga_(0.55)N SAM structure can increase significantly avalanche gain because of the increased hole ionization coefficient by using the relatively low Al-content AlGaN in the multiplication region. Meanwhile, a quarter-wave AlGaN/AIN distributed Bragg reflector structure at the bottom of the device is designed to remain a solar-blind characteristic of the heterostructure SAM-APDs.
基金The work wins the finance of Huo Ying-dong educational foundation
文摘A new method of fringe multiplication is presented in this paper.The method is simpleand applicable.Only one polarizer and one quarter-wave plate are adopted to get fringemultiplication by reflection.
文摘Electro dislocation multiplication and strain effect were investigated. TEM observation showed that when statically held for 15 min, the microstructure of dislocation cell in the specimens without current pulse turned to subgrains with few dislocations in cold rolled state, but when current pulse charged, there were a lot of dislocations although a more rapid recrystallization occurred concurrently; when deformed, the interior dislocations in the specimens without current pulse were annihilated due to dynamic recrystallization, but were not decreased in the current pulse charged specimens in dynamic recrystallization, instead increased. It is indicated that “electron wind” force created by current pulse produced a shear stress for dislocation slip, and caused a dislocation multiplication in static holding of 2091 Al Li alloy; when strain exerted, an additional shear stress was provided to increase the effect of current pulse on dislocation multiplication.
基金The Forecasting Research Base of Chinese Academy of Sciences in Xi an Jiaotong University,the National Natural Science Foundation of China (No.70773091)
文摘This research aims to improve the forecasting precision of electric quantity. It is discovered that the total electricity consumption considerably increased during the Spring Festival by the analysis of the electric quantity time series from 2002 to 2007 in Shandong province. The festival factor is ascertained to be one of the important seasonal factors affecting the electric quantity fluctuations, and the multiplication model for forecasting is improved by introducing corresponding variables and parameters. The computational results indicate that the average relative error of the new model decreases from 4.31% to 1.93% and the maximum relative error from 14.05% to 6.52% compared with those of the model when the festival factor is not considered. It shows that introducing the festival factor into the multiplication model for electric quantity forecasting evidently improves the precision.
基金supported in part by open project foundation of State Key Laboratory of Cryptology National Natural Science Foundation of China (NSFC) under Grant No. 61272492, No. 61572521 and No. 61309008Natural Science Foundation for Young of Shaanxi Province under Grant No. 2013JQ8013
文摘Matrix multiplication plays a pivotal role in the symmetric cipher algorithms, but it is one of the most complex and time consuming units, its performance directly affects the efficiency of cipher algorithms. Combined with the characteristics of VLIW processor and matrix multiplication of symmetric cipher algorithms, this paper extracted the reconfigurable elements and analyzed the principle of matrix multiplication, then designed the reconfigurable architecture of matrix multiplication of VLIW processor further, at last we put forward single instructions for matrix multiplication between 4×1 and 4×4 matrix or two 4×4 matrix over GF(2~8), through the instructions extension, the instructions could support larger dimension operations. The experiment shows that the instructions we designed supports different dimensions matrix multiplication and improves the processing speed of multiplication greatly.
基金supported by the National Key R&D Program of China (2018YFD0201500 and 2018YFD1000300)the National Natural Science Foundation of China (31972393)the China Agriculture Research System of MOF and MARA (CARS-26)
文摘‘Candidatus Liberibacter asiaticus(CLas)’,which causes citrus Huanglongbing(HLB)disease,has not been successfully cultured in vitro to date.Here,a rapid multiplication system for CLas was established through in vitro regeneration of axillary buds from CLas-infected‘Changyecheng’sweet orange(Citrus sinensis Osbeck).Stem segments with a single axillary bud were cultured in vitro to allow CLas to multiply in the regenerating axillary buds.A high CLas titer was detected in the regenerated shoots on an optimized medium at 30 days after germination(DAG).This titer was 28.2-fold higher than in the midribs from CLas-infected trees growing in the greenhouse.To minimize contamination during in vitro regeneration,CLas-infected axillary buds were micrografted onto seedlings of‘Changyecheng’sweet orange and cultured in a liquid medium.In this culture,the titers of CLas in regenerated shoots rapidly increased from 7.5×10^(4)to 1.4×10^(8)cellsμg^(-1)of citrus DNA during the first 40 DAG.The percentages of shoots with>1×10^(8)CLas cellsμg^(-1)DNA were 30 and 40%at 30 and 40 DAG,respectively.Direct tissue blot immunoassay(DTBIA)indicated that the distribution of CLas was much more uniform in regenerated plantlets than in CLas-infected trees growing in the greenhouse.The disease symptoms in the plantlets were die-back,stunted growth,leaf necrosis/yellowing,and defoliation.The death rate of the plantlets was 82.0%at 60 DAG.Our results show that CLas can effectively multiply in citrus plantlests in vitro.This method will be useful for studying plant-HLB interactions and for rapid screening of therapeutic compounds against CLas in citrus.
基金supported by NSF of China under grant U1908210National Key R&D Project of China under grant 2019YFB1802702。
文摘This paper exploits coding to speed up computation offloading in a multi-server mobile edge computing(MEC)network with straggling servers and channel fading.The specific task we consider is to compute the product between a user-generated input data matrix and a large-scale model matrix that is stored distributively across the multiple edge nodes.The key idea of coding is to introduce computation redundancy to improve robustness against straggling servers and to create communication redundancy to improve reliability against channel fading.We utilize the hybrid design of maximum distance separable(MDS)coding and repetition coding.Based on the hybrid coding scheme,we conduct theoretical analysis on the average task uploading time,average edge computing time,and average output downloading time,respectively and then obtain the end-to-end task execution time.Numerical results demonstrate that when the task uploading phase or the edge computing phase is the performance bottleneck,the hybrid coding reduces to MDS coding;when the downlink transmission is the bottleneck,the hybrid coding reduces to repetition coding.The hybrid coding also outperforms the entangled polynomial coding that causes higher uplink and downlink communication loads.
基金Project supported by the National Natural Science Foundation of China(Key Program)(Nos.11132004 and 51078145)
文摘Based on the precise integration method(PIM), a coupling technique of the high order multiplication perturbation method(HOMPM) and the reduction method is proposed to solve variable coefcient singularly perturbed two-point boundary value problems(TPBVPs) with one boundary layer. First, the inhomogeneous ordinary diferential equations(ODEs) are transformed into the homogeneous ODEs by variable coefcient dimensional expansion. Then, the whole interval is divided evenly, and the transfer matrix in each sub-interval is worked out through the HOMPM. Finally, a group of algebraic equations are given based on the relationship between the neighboring sub-intervals, which are solved by the reduction method. Numerical results show that the present method is highly efcient.
文摘In this paper, a yield model of polycrystalline metal based on thenonlinear irreversible multiplication is proposed, from which the kinetic yield equationsand the yield stress formulas can be deduced. Some yield phenomena and experimentalresults can be explained reasonably.
文摘Several algorithms based on homogeneous polynomials for multiplication of large integers are described in the paper. The homogeneity of polynomials provides several simplifications: reduction of system of equations and elimination of necessity to evaluate polynomials in points with larger coordinates. It is demonstrated that a two-stage implementation of the proposed and Toom-Cook algorithms asymptotically require twice as many standard multiplications than their direct implementation. A multistage implementation of these algorithms is also less efficient than their direct implementation. Although the proposed algorithms as well as the corresponding Toom-Cook algorithms require numerous algebraic additions, the Generalized Horner rule for evaluation of homogeneous polynomials, provided in the paper, decrease this number twice.
文摘Taro (Colocasia esculenta) and tannia (Xanthosoma sagittifolium) are commonly referred to as cocoyam in Nigeria. They are cherished for their rich taste, nutritional and medicinal properties. Traditionally, cocoyams are vegetatively propagated from tuber fragments, a practice that encourages pathogen distribution. For rapid multiplication and production of quality planting materials, tissue culture technology offers promising alternative compared to the traditional production methods. In this study different concentrations of ripped sweet orange (Citrus sinensis) juice were screened for regeneration and multiplication of 2 months old in vitro cocoyam shoot explants. Among the concentrations, maximum numbers of roots (37 ± 5) were observed in Murashige and Skoog (MS) medium supplemented with 10% orange juice after 8 weeks in culture compared to 16 ± 4 (roots) observed in the control medium. On shoot multiplicity, 16 ± 3 shoots were induced in the control medium in contrast to 12 ± 0.8 shoots in the MS medium supplemented with 10% orange juice after 8 weeks of culture. Higher concentrations (25% and 35%) of the orange juice supplemented medium resulted in concomitant inhibition of all the growth parameters. The study successfully established that ripped orange juice could substitute the use of conventional growth hormones cytokinins (BAP) and auxins (NAA) in in vitro regeneration and rapid multiplication of cocoyam shoot explants.
