Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography.In particular,the security of widely used public-key cryptosystems merits dee...Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography.In particular,the security of widely used public-key cryptosystems merits deep research to protect against new types of attacks.It is therefore highly meaningful to research cryptanalysis in the quantum computing environment.Shor proposed a wellknown factoring algorithm by finding the prime factors of a number n=pq,which is exponentially faster than the best known classical algorithm.The idea behind Shor's quantum factoring algorithm is a straightforward programming consequence of the following proposition:to factor n,it suffices to find the order r;once such an r is found,one can compute gcd(a^(r/2)±1,n)=p or q.For odd values of r it is assumed that the factors of n cannot be found(since a^(r/2)is not generally an integer).That is,the order r must be even.This restriction can be removed,however,by working from another angle.Based on the quantum inverse Fourier transform and phase estimation,this paper presents a new polynomial-time quantum algorithm for breaking RSA,without explicitly factoring the modulus n.The probability of success of the new algorithm is greater than 4φ(r)/π~2 r,exceeding that of the existing quantum algorithm forattacking RSA based on factorization.In constrast to the existing quantum algorithm for attacking RSA,the order r of the fixed point C for RSA does not need to be even.It changed the practices that cryptanalysts try to recover the private-key,directly from recovering the plaintext M to start,a ciphertext-only attack attacking RSA is proposed.展开更多
Shor in 1994 proposed a quantum polynomial-time algorithm for finding the order r of an element a in the multiplicative group Z_(n)^(*),which can be used to factor the integer n by computing gcd(a^(r/2)±1,n),and ...Shor in 1994 proposed a quantum polynomial-time algorithm for finding the order r of an element a in the multiplicative group Z_(n)^(*),which can be used to factor the integer n by computing gcd(a^(r/2)±1,n),and hence break the famous RSA cryptosystem.However,the order r must be even.This restriction can be removed.So in this paper,we propose a quantum polynomial-time fixed-point attack for directly recovering the RSA plaintext M from the ciphertext C,without explicitly factoring the modulus n.Compared to Shor’s algorithm,the order r of the fixed-point C for RSA(e,n)satisfying C^(er)≡C(mod n)does not need to be even.Moreover,the success probability of the new algorithm is at least 4φ(r)/π^(2)r and higher than that of Shor’s algorithm,though the time complexity for both algorithms is about the same.展开更多
The aim of this paper is to gain insight into the nonlinear vibration feature of a dynamic model of a gas turbine.First,a rod fastening rotor-bearing coupling model with fixed-point rubbing is proposed,where the fract...The aim of this paper is to gain insight into the nonlinear vibration feature of a dynamic model of a gas turbine.First,a rod fastening rotor-bearing coupling model with fixed-point rubbing is proposed,where the fractal theory and the finite element method are utilized.For contact analysis,a novel contact force model is introduced in this paper.Meanwhile,the Coulomb model is adopted to expound the friction characteristics.Second,the governing equations of motion of the rotor system are numerically solved,and the nonlinear dynamic characteristics are analyzed in terms of the bifurcation diagram,Poincarémap,and time history.Third,the potential effects provided by contact degree of joint interface,distribution position,and amount of contact layer are discussed in detail.Finally,the contrast analysis between the integral rotor and the rod fastening rotor is conducted under the condition of fixed-point rubbing.展开更多
In this paper, we study the normality criteria of meromorphic functions concerning shared fixed-points, we obtain: Let F be a family of meromorphic functions defined in a domain D. Let n, k ≥ 2 be two positive intege...In this paper, we study the normality criteria of meromorphic functions concerning shared fixed-points, we obtain: Let F be a family of meromorphic functions defined in a domain D. Let n, k ≥ 2 be two positive integers. For every f ∈ F, all of whose zeros have multiplicity at least (nk+2)/(n-1). If f(f(k))nand g(g(k))nshare z in D for each pair of functions f and g, then F is normal.展开更多
The present paper is devoted to a novel smoothing function method for convex quadratic programming problem with mixed constrains, which has important application in mechanics and engineering science. The problem is re...The present paper is devoted to a novel smoothing function method for convex quadratic programming problem with mixed constrains, which has important application in mechanics and engineering science. The problem is reformulated as a system of non-smooth equations, and then a smoothing function for the system of non-smooth equations is proposed. The condition of convergences of this iteration algorithm is given. Theory analysis and primary numerical results illustrate that this method is feasible and effective.展开更多
With the continuous increasing of circuit scale, the problem of power consumption is paid much more attention than before, especially in large designs. In this paper, an experience of optimizing the power consumption ...With the continuous increasing of circuit scale, the problem of power consumption is paid much more attention than before, especially in large designs. In this paper, an experience of optimizing the power consumption of the 16-bit datapath in a 32-bit reconfigurable pipelined Digital Signal Processor (DSP) is introduced. By keeping the old input values and preventing the useless switching of the logic blocks on the datapath, the power consumption is much lowered. At the same time, by relocating some logic blocks between different pipeline stages and employing some data forward logics, a better balanced pipeline is achieved to lower the power consumption for conditional computation instructions at very low timing and area costs. The effectivity of these power optimization technologies are proved by the experimental results. Finally, some ideas about how to reduce the power consumption of circuits are proposed, which are very effective and useful in practice designs, especially in pipelined ones.展开更多
Datapath accounts for a considerable part of power consumption in VLSI circuit design. This paper presents a method for physical implementation of datapath to achieve low power consumption. Regularity is a characteris...Datapath accounts for a considerable part of power consumption in VLSI circuit design. This paper presents a method for physical implementation of datapath to achieve low power consumption. Regularity is a characteristic of datapath and the key of the proposed method, where synthesis is tightly combined with placement to make full use of regularity, so that low power consumption is achieved. In This paper, a new concept of Synthesis In Relative Placement (SIRP) is given to deal with the semi-regularity in some datapath. Experimental results of a sample circuit validated the proposed method.展开更多
The attractive fixed-point solution of a nonlinear cascade model is stud- ied for the homogeneous isotropic turbulence containing a parameter C, introduced by Desnyansky and Novikov. With a traditional constant positi...The attractive fixed-point solution of a nonlinear cascade model is stud- ied for the homogeneous isotropic turbulence containing a parameter C, introduced by Desnyansky and Novikov. With a traditional constant positive external force added on the first shell equation, it can be found that the attractive fixed-point solution of the model depends on both the parameter C and the external force. Thus, an explicit force is introduced to remove the effects of the external force on the attractive fixed-point solu- tion. F^arthermore, two groups of attractive fixed-point solutions are derived theoretically and studied numerically. One of the groups has the same scaling behavior of the velocity in the whole inertial range and agrees well with those observed by Bell and Nelkin for the nonnegative parameters. The other is found to have different scaling behaviors of the velocity at the odd and even number shells for the negative parameters. This special characteristic may be used to study the anomalous scaling behavior of the turbulence.展开更多
For the unsorted database quantum search with the unknown fraction λ of target items, there are mainly two kinds of methods, i.e., fixed-point and trail-and-error.(i) In terms of the fixed-point method, Yoder et al. ...For the unsorted database quantum search with the unknown fraction λ of target items, there are mainly two kinds of methods, i.e., fixed-point and trail-and-error.(i) In terms of the fixed-point method, Yoder et al. [Phys. Rev. Lett.113 210501(2014)] claimed that the quadratic speedup over classical algorithms has been achieved. However, in this paper, we point out that this is not the case, because the query complexity of Yoder’s algorithm is actually in O(1/λ01/2)rather than O(1/λ1/2), where λ0 is a known lower bound of λ.(ii) In terms of the trail-and-error method, currently the algorithm without randomness has to take more than 1 times queries or iterations than the algorithm with randomly selected parameters. For the above problems, we provide the first hybrid quantum search algorithm based on the fixed-point and trail-and-error methods, where the matched multiphase Grover operations are trialed multiple times and the number of iterations increases exponentially along with the number of trials. The upper bound of expected queries as well as the optimal parameters are derived. Compared with Yoder’s algorithm, the query complexity of our algorithm indeed achieves the optimal scaling in λ for quantum search, which reconfirms the practicality of the fixed-point method. In addition, our algorithm also does not contain randomness, and compared with the existing deterministic algorithm, the query complexity can be reduced by about 1/3. Our work provides a new idea for the research on fixed-point and trial-and-error quantum search.展开更多
Objective: To study the effects of the fixed-point mutant on growth cycle and ultrastructure of the Calmodulin fixed-point mutant yeast. Methods: Growth cycle and ultrastructure of the Calmodulin fixed-point mutant ye...Objective: To study the effects of the fixed-point mutant on growth cycle and ultrastructure of the Calmodulin fixed-point mutant yeast. Methods: Growth cycle and ultrastructure of the Calmodulin fixed-point mutant yeast were studied by using cytometry and scan electron microscope. Results: After culture at 30'C for 36 h, the content of aneuploidy of the temperature-sensitive recombinant yeast monoploid B(F92+) and E(F89+FH1 + ) strains were 63. 87% and 63. 55%, respectively. These were significantly different from control OP<0. 01) ; The content of the non-temperature-sensitive recombinant yeast monoploid A(F89+) and C(F141+) strains were 100. 00% and 99. 97% , respectively, which were not significantly different from control value (P>0. 05). Observed by scan electron microscope, the control group, A and C strain's buds were spherical or oval and those bud-necks were fairly shorter; the B and E strain's buds were slender, some cell were abnormal and some buds might show spherical or oval. Conclusion: DNA division and growth velocity of the temperature-sensitive recombinant B and E strains are slower than those of control group and the non-temperature-sensitive recombinant A and C strains.展开更多
Asynchronous federated learning(AsynFL)can effectivelymitigate the impact of heterogeneity of edge nodes on joint training while satisfying participant user privacy protection and data security.However,the frequent ex...Asynchronous federated learning(AsynFL)can effectivelymitigate the impact of heterogeneity of edge nodes on joint training while satisfying participant user privacy protection and data security.However,the frequent exchange of massive data can lead to excess communication overhead between edge and central nodes regardless of whether the federated learning(FL)algorithm uses synchronous or asynchronous aggregation.Therefore,there is an urgent need for a method that can simultaneously take into account device heterogeneity and edge node energy consumption reduction.This paper proposes a novel Fixed-point Asynchronous Federated Learning(FixedAsynFL)algorithm,which could mitigate the resource consumption caused by frequent data communication while alleviating the effect of device heterogeneity.FixedAsynFL uses fixed-point quantization to compress the local and global models in AsynFL.In order to balance energy consumption and learning accuracy,this paper proposed a quantization scale selection mechanism.This paper examines the mathematical relationship between the quantization scale and energy consumption of the computation/communication process in the FixedAsynFL.Based on considering the upper bound of quantization noise,this paper optimizes the quantization scale by minimizing communication and computation consumption.This paper performs pertinent experiments on the MNIST dataset with several edge nodes of different computing efficiency.The results show that the FixedAsynFL algorithm with an 8-bit quantization can significantly reduce the communication data size by 81.3%and save the computation energy in the training phase by 74.9%without significant loss of accuracy.According to the experimental results,we can see that the proposed AsynFixedFL algorithm can effectively solve the problem of device heterogeneity and energy consumption limitation of edge nodes.展开更多
Discrete Tomography(DT)is a technology that uses image projection to reconstruct images.Its reconstruction problem,especially the binary image(0–1matrix)has attracted strong attention.In this study,a fixed point iter...Discrete Tomography(DT)is a technology that uses image projection to reconstruct images.Its reconstruction problem,especially the binary image(0–1matrix)has attracted strong attention.In this study,a fixed point iterative method of integer programming based on intelligent optimization is proposed to optimize the reconstructedmodel.The solution process can be divided into two procedures.First,the DT problem is reformulated into a polyhedron judgment problembased on lattice basis reduction.Second,the fixed-point iterativemethod of Dang and Ye is used to judge whether an integer point exists in the polyhedron of the previous program.All the programs involved in this study are written in MATLAB.The final experimental data show that this method is obviously better than the branch and bound method in terms of computational efficiency,especially in the case of high dimension.The branch and bound method requires more branch operations and takes a long time.It also needs to store a large number of leaf node boundaries and the corresponding consumptionmatrix,which occupies a largememory space.展开更多
In this paper, we provide an aggregate function homotopy interior point method to solve a class of Brouwer fixed-point problems. Compared with the homotopy method （proposed by Yu and Lin, Appl. Math. Comput., 74（199...In this paper, we provide an aggregate function homotopy interior point method to solve a class of Brouwer fixed-point problems. Compared with the homotopy method （proposed by Yu and Lin, Appl. Math. Comput., 74（1996）, 65）, the main adavantages of this method are as foUows： on the one hand, it can solve the Brouwer fixed-point problems in a broader class of nonconvex subsets Ω in R^n （in this paper, we let Ω={x∈ R^n ： gi（x） ≤0, i= 1,... , m}）; on the other hand, it can also deal with the subsets Ω with larger amount of constraints more effectively.展开更多
Fixed-point fast sweeping WENO methods are a class of efficient high-order numerical methods to solve steady-state solutions of hyperbolic partial differential equations(PDEs).The Gauss-Seidel iterations and alternati...Fixed-point fast sweeping WENO methods are a class of efficient high-order numerical methods to solve steady-state solutions of hyperbolic partial differential equations(PDEs).The Gauss-Seidel iterations and alternating sweeping strategy are used to cover characteristics of hyperbolic PDEs in each sweeping order to achieve fast convergence rate to steady-state solutions.A nice property of fixed-point fast sweeping WENO methods which distinguishes them from other fast sweeping methods is that they are explicit and do not require inverse operation of nonlinear local systems.Hence,they are easy to be applied to a general hyperbolic system.To deal with the difficulties associated with numerical boundary treatment when high-order finite difference methods on a Cartesian mesh are used to solve hyperbolic PDEs on complex domains,inverse Lax-Wendroff(ILW)procedures were developed as a very effective approach in the literature.In this paper,we combine a fifthorder fixed-point fast sweeping WENO method with an ILW procedure to solve steadystate solution of hyperbolic conservation laws on complex computing regions.Numerical experiments are performed to test the method in solving various problems including the cases with the physical boundary not aligned with the grids.Numerical results show highorder accuracy and good performance of the method.Furthermore,the method is compared with the popular third-order total variation diminishing Runge-Kutta(TVD-RK3)time-marching method for steady-state computations.Numerical examples show that for most of examples,the fixed-point fast sweeping method saves more than half CPU time costs than TVD-RK3 to converge to steady-state solutions.展开更多
In this paper, we modify the homotopy method （proposed by Yu and Lin, Appl. Math. Comput., 74（1996）, 65） and hence make the modified method be able to solve Brouwer fixed-point problems in a broader class of nonco...In this paper, we modify the homotopy method （proposed by Yu and Lin, Appl. Math. Comput., 74（1996）, 65） and hence make the modified method be able to solve Brouwer fixed-point problems in a broader class of nonconvex subsets in Rn. In addition, a simple example is given to show the effectiveness of the modified method.展开更多
Using the hypothesis that data transmitted by different users are statistically independent of each other,this paper proposes a fixed-point blind adaptive multiuser detection algorithm for Time-Hopping (TH) Impulse Ra...Using the hypothesis that data transmitted by different users are statistically independent of each other,this paper proposes a fixed-point blind adaptive multiuser detection algorithm for Time-Hopping (TH) Impulse Radio (IR) Ultra Wide Band (UWB) systems in multipath channel,which is based on Independent Component Analysis (ICA) idea. The proposed algorithm employs maximizing negentropy criterion to separate the data packets of different users. Then the user characteristic se-quences are utilized to identify the data packet order of the desired user. This algorithm only needs the desired user’s characteristic sequence instead of channel information,power information and time-hoping code of any user. Due to using hypothesis of statistical independence among users,the proposed algorithm has the outstanding Bit Error Rate (BER) performance and the excellent ability of near-far resistance. Simulation results demonstrate that this algorithm has the performance close to that of Maximum-Likelihood (ML) algorithm and is a suboptimum blind adaptive multiuser detection algorithm of excellent near-far resistance and low complexity.展开更多
In this letter, a simple and efficient method of image speckle reduction for polari- metric SAR is put forward. It is based on the fast fixed-point ICA (Independent Component Analysis) algorithm of orthogonal and symm...In this letter, a simple and efficient method of image speckle reduction for polari- metric SAR is put forward. It is based on the fast fixed-point ICA (Independent Component Analysis) algorithm of orthogonal and symmetric matrix. Simulation experiment is carried out to separate speckle noise from the polarimetric SAR images, and it indicates that this algorithm has high convergency speed and stability, the image speckle noise is reduced effectively and the speckle index is low, and the image quality is improved obviously.展开更多
基金partially supported by he State Key Program of National Natural Science of China No.61332019Major State Basic Research Development Program of China(973 Program)No.2014CB340601+1 种基金the National Science Foundation of China No.61202386,61402339the National Cryptography Development Fund No.MMJJ201701304
文摘Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography.In particular,the security of widely used public-key cryptosystems merits deep research to protect against new types of attacks.It is therefore highly meaningful to research cryptanalysis in the quantum computing environment.Shor proposed a wellknown factoring algorithm by finding the prime factors of a number n=pq,which is exponentially faster than the best known classical algorithm.The idea behind Shor's quantum factoring algorithm is a straightforward programming consequence of the following proposition:to factor n,it suffices to find the order r;once such an r is found,one can compute gcd(a^(r/2)±1,n)=p or q.For odd values of r it is assumed that the factors of n cannot be found(since a^(r/2)is not generally an integer).That is,the order r must be even.This restriction can be removed,however,by working from another angle.Based on the quantum inverse Fourier transform and phase estimation,this paper presents a new polynomial-time quantum algorithm for breaking RSA,without explicitly factoring the modulus n.The probability of success of the new algorithm is greater than 4φ(r)/π~2 r,exceeding that of the existing quantum algorithm forattacking RSA based on factorization.In constrast to the existing quantum algorithm for attacking RSA,the order r of the fixed point C for RSA does not need to be even.It changed the practices that cryptanalysts try to recover the private-key,directly from recovering the plaintext M to start,a ciphertext-only attack attacking RSA is proposed.
基金Supported by Nanhu Scholars Program for Young Scholars of Xinyang Normal University。
文摘Shor in 1994 proposed a quantum polynomial-time algorithm for finding the order r of an element a in the multiplicative group Z_(n)^(*),which can be used to factor the integer n by computing gcd(a^(r/2)±1,n),and hence break the famous RSA cryptosystem.However,the order r must be even.This restriction can be removed.So in this paper,we propose a quantum polynomial-time fixed-point attack for directly recovering the RSA plaintext M from the ciphertext C,without explicitly factoring the modulus n.Compared to Shor’s algorithm,the order r of the fixed-point C for RSA(e,n)satisfying C^(er)≡C(mod n)does not need to be even.Moreover,the success probability of the new algorithm is at least 4φ(r)/π^(2)r and higher than that of Shor’s algorithm,though the time complexity for both algorithms is about the same.
基金the National Natural Science Foundation of China(No.12172307)the Key Laboratory of Vibration and Control of Aero-Propulsion System,Ministry of Education,Northeastern University of China(No.VCAME202103)the Fundamental Research Funds for the Central Universities in Southwest Jiaotong University of China(No.2682021ZTPY036)。
文摘The aim of this paper is to gain insight into the nonlinear vibration feature of a dynamic model of a gas turbine.First,a rod fastening rotor-bearing coupling model with fixed-point rubbing is proposed,where the fractal theory and the finite element method are utilized.For contact analysis,a novel contact force model is introduced in this paper.Meanwhile,the Coulomb model is adopted to expound the friction characteristics.Second,the governing equations of motion of the rotor system are numerically solved,and the nonlinear dynamic characteristics are analyzed in terms of the bifurcation diagram,Poincarémap,and time history.Third,the potential effects provided by contact degree of joint interface,distribution position,and amount of contact layer are discussed in detail.Finally,the contrast analysis between the integral rotor and the rod fastening rotor is conducted under the condition of fixed-point rubbing.
文摘In this paper, we study the normality criteria of meromorphic functions concerning shared fixed-points, we obtain: Let F be a family of meromorphic functions defined in a domain D. Let n, k ≥ 2 be two positive integers. For every f ∈ F, all of whose zeros have multiplicity at least (nk+2)/(n-1). If f(f(k))nand g(g(k))nshare z in D for each pair of functions f and g, then F is normal.
文摘The present paper is devoted to a novel smoothing function method for convex quadratic programming problem with mixed constrains, which has important application in mechanics and engineering science. The problem is reformulated as a system of non-smooth equations, and then a smoothing function for the system of non-smooth equations is proposed. The condition of convergences of this iteration algorithm is given. Theory analysis and primary numerical results illustrate that this method is feasible and effective.
文摘With the continuous increasing of circuit scale, the problem of power consumption is paid much more attention than before, especially in large designs. In this paper, an experience of optimizing the power consumption of the 16-bit datapath in a 32-bit reconfigurable pipelined Digital Signal Processor (DSP) is introduced. By keeping the old input values and preventing the useless switching of the logic blocks on the datapath, the power consumption is much lowered. At the same time, by relocating some logic blocks between different pipeline stages and employing some data forward logics, a better balanced pipeline is achieved to lower the power consumption for conditional computation instructions at very low timing and area costs. The effectivity of these power optimization technologies are proved by the experimental results. Finally, some ideas about how to reduce the power consumption of circuits are proposed, which are very effective and useful in practice designs, especially in pipelined ones.
基金Project (No. 2002 AA1Z1140) supported by the Hi-Tech Research and Development Program (863) of China and the Fork Ying Tong Education Foundation (No. 94031), China
文摘Datapath accounts for a considerable part of power consumption in VLSI circuit design. This paper presents a method for physical implementation of datapath to achieve low power consumption. Regularity is a characteristic of datapath and the key of the proposed method, where synthesis is tightly combined with placement to make full use of regularity, so that low power consumption is achieved. In This paper, a new concept of Synthesis In Relative Placement (SIRP) is given to deal with the semi-regularity in some datapath. Experimental results of a sample circuit validated the proposed method.
基金Project supported by the National Natural Science Foundation of China (No. 10902007)he National Basic Research Program of China (973 Program) (No. 2009CB724001)
文摘The attractive fixed-point solution of a nonlinear cascade model is stud- ied for the homogeneous isotropic turbulence containing a parameter C, introduced by Desnyansky and Novikov. With a traditional constant positive external force added on the first shell equation, it can be found that the attractive fixed-point solution of the model depends on both the parameter C and the external force. Thus, an explicit force is introduced to remove the effects of the external force on the attractive fixed-point solu- tion. F^arthermore, two groups of attractive fixed-point solutions are derived theoretically and studied numerically. One of the groups has the same scaling behavior of the velocity in the whole inertial range and agrees well with those observed by Bell and Nelkin for the nonnegative parameters. The other is found to have different scaling behaviors of the velocity at the odd and even number shells for the negative parameters. This special characteristic may be used to study the anomalous scaling behavior of the turbulence.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504430 and 61502526)the National Basic Research Program of China(Grant No.2013CB338002)
文摘For the unsorted database quantum search with the unknown fraction λ of target items, there are mainly two kinds of methods, i.e., fixed-point and trail-and-error.(i) In terms of the fixed-point method, Yoder et al. [Phys. Rev. Lett.113 210501(2014)] claimed that the quadratic speedup over classical algorithms has been achieved. However, in this paper, we point out that this is not the case, because the query complexity of Yoder’s algorithm is actually in O(1/λ01/2)rather than O(1/λ1/2), where λ0 is a known lower bound of λ.(ii) In terms of the trail-and-error method, currently the algorithm without randomness has to take more than 1 times queries or iterations than the algorithm with randomly selected parameters. For the above problems, we provide the first hybrid quantum search algorithm based on the fixed-point and trail-and-error methods, where the matched multiphase Grover operations are trialed multiple times and the number of iterations increases exponentially along with the number of trials. The upper bound of expected queries as well as the optimal parameters are derived. Compared with Yoder’s algorithm, the query complexity of our algorithm indeed achieves the optimal scaling in λ for quantum search, which reconfirms the practicality of the fixed-point method. In addition, our algorithm also does not contain randomness, and compared with the existing deterministic algorithm, the query complexity can be reduced by about 1/3. Our work provides a new idea for the research on fixed-point and trial-and-error quantum search.
基金Supported by the National Natural Science Foundation of China (No. 39870012)
文摘Objective: To study the effects of the fixed-point mutant on growth cycle and ultrastructure of the Calmodulin fixed-point mutant yeast. Methods: Growth cycle and ultrastructure of the Calmodulin fixed-point mutant yeast were studied by using cytometry and scan electron microscope. Results: After culture at 30'C for 36 h, the content of aneuploidy of the temperature-sensitive recombinant yeast monoploid B(F92+) and E(F89+FH1 + ) strains were 63. 87% and 63. 55%, respectively. These were significantly different from control OP<0. 01) ; The content of the non-temperature-sensitive recombinant yeast monoploid A(F89+) and C(F141+) strains were 100. 00% and 99. 97% , respectively, which were not significantly different from control value (P>0. 05). Observed by scan electron microscope, the control group, A and C strain's buds were spherical or oval and those bud-necks were fairly shorter; the B and E strain's buds were slender, some cell were abnormal and some buds might show spherical or oval. Conclusion: DNA division and growth velocity of the temperature-sensitive recombinant B and E strains are slower than those of control group and the non-temperature-sensitive recombinant A and C strains.
基金This work was funded by National Key R&D Program of China(Grant No.2020YFB0906003).
文摘Asynchronous federated learning(AsynFL)can effectivelymitigate the impact of heterogeneity of edge nodes on joint training while satisfying participant user privacy protection and data security.However,the frequent exchange of massive data can lead to excess communication overhead between edge and central nodes regardless of whether the federated learning(FL)algorithm uses synchronous or asynchronous aggregation.Therefore,there is an urgent need for a method that can simultaneously take into account device heterogeneity and edge node energy consumption reduction.This paper proposes a novel Fixed-point Asynchronous Federated Learning(FixedAsynFL)algorithm,which could mitigate the resource consumption caused by frequent data communication while alleviating the effect of device heterogeneity.FixedAsynFL uses fixed-point quantization to compress the local and global models in AsynFL.In order to balance energy consumption and learning accuracy,this paper proposed a quantization scale selection mechanism.This paper examines the mathematical relationship between the quantization scale and energy consumption of the computation/communication process in the FixedAsynFL.Based on considering the upper bound of quantization noise,this paper optimizes the quantization scale by minimizing communication and computation consumption.This paper performs pertinent experiments on the MNIST dataset with several edge nodes of different computing efficiency.The results show that the FixedAsynFL algorithm with an 8-bit quantization can significantly reduce the communication data size by 81.3%and save the computation energy in the training phase by 74.9%without significant loss of accuracy.According to the experimental results,we can see that the proposed AsynFixedFL algorithm can effectively solve the problem of device heterogeneity and energy consumption limitation of edge nodes.
基金funded by the NSFC under Grant Nos.61803279,71471091,62003231 and 51874205in part by the Qing Lan Project of Jiangsu,in part by the China Postdoctoral Science Foundation under Grant Nos.2020M671596 and 2021M692369+2 种基金in part by the Suzhou Science and Technology Development Plan Project(Key Industry Technology Innovation)under Grant No.SYG202114in part by the Natural Science Foundation of Jiangsu Province under Grant No.BK20200989Postdoctoral Research Funding Program of Jiangsu Province.
文摘Discrete Tomography(DT)is a technology that uses image projection to reconstruct images.Its reconstruction problem,especially the binary image(0–1matrix)has attracted strong attention.In this study,a fixed point iterative method of integer programming based on intelligent optimization is proposed to optimize the reconstructedmodel.The solution process can be divided into two procedures.First,the DT problem is reformulated into a polyhedron judgment problembased on lattice basis reduction.Second,the fixed-point iterativemethod of Dang and Ye is used to judge whether an integer point exists in the polyhedron of the previous program.All the programs involved in this study are written in MATLAB.The final experimental data show that this method is obviously better than the branch and bound method in terms of computational efficiency,especially in the case of high dimension.The branch and bound method requires more branch operations and takes a long time.It also needs to store a large number of leaf node boundaries and the corresponding consumptionmatrix,which occupies a largememory space.
文摘In this paper, we provide an aggregate function homotopy interior point method to solve a class of Brouwer fixed-point problems. Compared with the homotopy method （proposed by Yu and Lin, Appl. Math. Comput., 74（1996）, 65）, the main adavantages of this method are as foUows： on the one hand, it can solve the Brouwer fixed-point problems in a broader class of nonconvex subsets Ω in R^n （in this paper, we let Ω={x∈ R^n ： gi（x） ≤0, i= 1,... , m}）; on the other hand, it can also deal with the subsets Ω with larger amount of constraints more effectively.
基金Research was supported by the NSFC Grant 11872210Research was supported by the NSFC Grant 11872210 and Grant No.MCMS-I-0120G01+1 种基金Research supported in part by the AFOSR Grant FA9550-20-1-0055NSF Grant DMS-2010107.
文摘Fixed-point fast sweeping WENO methods are a class of efficient high-order numerical methods to solve steady-state solutions of hyperbolic partial differential equations(PDEs).The Gauss-Seidel iterations and alternating sweeping strategy are used to cover characteristics of hyperbolic PDEs in each sweeping order to achieve fast convergence rate to steady-state solutions.A nice property of fixed-point fast sweeping WENO methods which distinguishes them from other fast sweeping methods is that they are explicit and do not require inverse operation of nonlinear local systems.Hence,they are easy to be applied to a general hyperbolic system.To deal with the difficulties associated with numerical boundary treatment when high-order finite difference methods on a Cartesian mesh are used to solve hyperbolic PDEs on complex domains,inverse Lax-Wendroff(ILW)procedures were developed as a very effective approach in the literature.In this paper,we combine a fifthorder fixed-point fast sweeping WENO method with an ILW procedure to solve steadystate solution of hyperbolic conservation laws on complex computing regions.Numerical experiments are performed to test the method in solving various problems including the cases with the physical boundary not aligned with the grids.Numerical results show highorder accuracy and good performance of the method.Furthermore,the method is compared with the popular third-order total variation diminishing Runge-Kutta(TVD-RK3)time-marching method for steady-state computations.Numerical examples show that for most of examples,the fixed-point fast sweeping method saves more than half CPU time costs than TVD-RK3 to converge to steady-state solutions.
文摘In this paper, we modify the homotopy method （proposed by Yu and Lin, Appl. Math. Comput., 74（1996）, 65） and hence make the modified method be able to solve Brouwer fixed-point problems in a broader class of nonconvex subsets in Rn. In addition, a simple example is given to show the effectiveness of the modified method.
文摘Using the hypothesis that data transmitted by different users are statistically independent of each other,this paper proposes a fixed-point blind adaptive multiuser detection algorithm for Time-Hopping (TH) Impulse Radio (IR) Ultra Wide Band (UWB) systems in multipath channel,which is based on Independent Component Analysis (ICA) idea. The proposed algorithm employs maximizing negentropy criterion to separate the data packets of different users. Then the user characteristic se-quences are utilized to identify the data packet order of the desired user. This algorithm only needs the desired user’s characteristic sequence instead of channel information,power information and time-hoping code of any user. Due to using hypothesis of statistical independence among users,the proposed algorithm has the outstanding Bit Error Rate (BER) performance and the excellent ability of near-far resistance. Simulation results demonstrate that this algorithm has the performance close to that of Maximum-Likelihood (ML) algorithm and is a suboptimum blind adaptive multiuser detection algorithm of excellent near-far resistance and low complexity.
基金Supported by the University Doctorate Special Research Fund (No.20030614001).
文摘In this letter, a simple and efficient method of image speckle reduction for polari- metric SAR is put forward. It is based on the fast fixed-point ICA (Independent Component Analysis) algorithm of orthogonal and symmetric matrix. Simulation experiment is carried out to separate speckle noise from the polarimetric SAR images, and it indicates that this algorithm has high convergency speed and stability, the image speckle noise is reduced effectively and the speckle index is low, and the image quality is improved obviously.
