We give algorithms to factorize large integers in the duality computer. We provide three duality algorithms for factorization based on a naive factorization method, the Shor algorithm in quantum computing, and the Fer...We give algorithms to factorize large integers in the duality computer. We provide three duality algorithms for factorization based on a naive factorization method, the Shor algorithm in quantum computing, and the Fermat＇s method in classical computing. All these algorithms may be polynomial in the input size.展开更多
A three-part comb decimator is presented in this paper, for the applications with severe requirements of circuit performance and frequency response. Based on the modified prime factorization method and multistage poly...A three-part comb decimator is presented in this paper, for the applications with severe requirements of circuit performance and frequency response. Based on the modified prime factorization method and multistage polyphase decomposition, an efficient non-recursive structure for the cascaded integrator-comb （CIC） decimation filter is derived. Utilizing this structure as the core part, the proposed comb decimator can not only loosen the decimation ratio＇s limitation, but also balance the tradeoff among the overall power consumption, circuit area and maximum speed. Further, to improve the frequency response of the comb decimator, a cos-prefilter is introduced as the preprocessing part for increasing the aliasing rejection, and an optimum sin-based filter is used as the compensation part for decreasing the passband droop.展开更多
In this paper,we have proved that if one of the following conditions is satisfed,then the equations in title has no positive integer solution:①D=∏si=1P i or D=2∏si=1P i and \{ P i≡3 (mod 4)\} (1≤i≤s) or P i≡5 (...In this paper,we have proved that if one of the following conditions is satisfed,then the equations in title has no positive integer solution:①D=∏si=1P i or D=2∏si=1P i and \{ P i≡3 (mod 4)\} (1≤i≤s) or P i≡5 (mod 8) (i≤i≤s); ② D=∏si=1P i-1 (mod 12), 1≤s≤7 and \{D≠3·5·7·11·17·577,7·19·29·41·59·577;\} ③ D=2∏si=1P i,1≤s≤6 and \{D ≠2·17,2·3·5·7·11·17,2·17·113·239·337·577·665857;\} ④ D=∏si=1P i≡-1 (mod 12), 1≤s≤3 and D≠ 5·7,29·41·239.展开更多
Define the total number of distinct prime factors of an odd perfect number n asω(n). We prove that if n is an odd perfect number which is relatively prime to 3 and 5 and7, then ω(n) ≥ 107. And using this result, we...Define the total number of distinct prime factors of an odd perfect number n asω(n). We prove that if n is an odd perfect number which is relatively prime to 3 and 5 and7, then ω(n) ≥ 107. And using this result, we give a conclusion that the third largest prime factor of such an odd perfect number exceeds 1283.展开更多
For any integer n ≥ 2, let P（n） be the largest prime factor of n. In this paper, we prove 1 This that the number of primes p 〈 x with P（p- 1） ≥ pC is more than （1 -c＋o（1））π（x） for 0 〈 c 〈 1/2 extends...For any integer n ≥ 2, let P（n） be the largest prime factor of n. In this paper, we prove 1 This that the number of primes p 〈 x with P（p- 1） ≥ pC is more than （1 -c＋o（1））π（x） for 0 〈 c 〈 1/2 extends a recent result of Luca, Menares and Madariaga for1/4≤c≤1/2. We also pose two conjectures for further research.展开更多
Let P（x） denote the greatest prime factor of ∏<sub>x【n≤x+x<sup>1/2</sup></sub>n. In this paper, we shall prove that P（x）】x<sup>0.728</sup>holds true for sufficiently large x.
Let n = p1p2 ··· pk, where pi(1 ≤ i ≤ k) are primes in the descending order and are not all equal. Let Ωk(n) = P(p1 + p2)P(p2 + p3) ··· P(pk-1+ pk)P(pk+ p1), where P(n) is the largest ...Let n = p1p2 ··· pk, where pi(1 ≤ i ≤ k) are primes in the descending order and are not all equal. Let Ωk(n) = P(p1 + p2)P(p2 + p3) ··· P(pk-1+ pk)P(pk+ p1), where P(n) is the largest prime factor of n. Define w0(n) = n and wi(n) = w(wi-1(n)) for all integers i ≥ 1. The smallest integer s for which there exists a positive integer t such thatΩs k(n) = Ωs+t k(n) is called the index of periodicity of n. The authors investigate the index of periodicity of n.展开更多
基金The project supported by the 973 Program under Grant No. 2006CB921106, National Natural Science Foundation of China under Grant Nos. 10325521 and 60433050, and the Key Project 306020 and Science Research Fund of Doctoval Program of the Ministry of Education of China
文摘We give algorithms to factorize large integers in the duality computer. We provide three duality algorithms for factorization based on a naive factorization method, the Shor algorithm in quantum computing, and the Fermat＇s method in classical computing. All these algorithms may be polynomial in the input size.
基金Supported by the China Postdoctoral Science Foundation （20080431379）.
文摘A three-part comb decimator is presented in this paper, for the applications with severe requirements of circuit performance and frequency response. Based on the modified prime factorization method and multistage polyphase decomposition, an efficient non-recursive structure for the cascaded integrator-comb （CIC） decimation filter is derived. Utilizing this structure as the core part, the proposed comb decimator can not only loosen the decimation ratio＇s limitation, but also balance the tradeoff among the overall power consumption, circuit area and maximum speed. Further, to improve the frequency response of the comb decimator, a cos-prefilter is introduced as the preprocessing part for increasing the aliasing rejection, and an optimum sin-based filter is used as the compensation part for decreasing the passband droop.
文摘In this paper,we have proved that if one of the following conditions is satisfed,then the equations in title has no positive integer solution:①D=∏si=1P i or D=2∏si=1P i and \{ P i≡3 (mod 4)\} (1≤i≤s) or P i≡5 (mod 8) (i≤i≤s); ② D=∏si=1P i-1 (mod 12), 1≤s≤7 and \{D≠3·5·7·11·17·577,7·19·29·41·59·577;\} ③ D=2∏si=1P i,1≤s≤6 and \{D ≠2·17,2·3·5·7·11·17,2·17·113·239·337·577·665857;\} ④ D=∏si=1P i≡-1 (mod 12), 1≤s≤3 and D≠ 5·7,29·41·239.
基金Foundation item： Supported by the Science Foundation of Kashgar Teacher＇s College（112390）
文摘Define the total number of distinct prime factors of an odd perfect number n asω(n). We prove that if n is an odd perfect number which is relatively prime to 3 and 5 and7, then ω(n) ≥ 107. And using this result, we give a conclusion that the third largest prime factor of such an odd perfect number exceeds 1283.
基金Supported by National Natural Science Foundation of China(Grant Nos.11571174,11401411 and 11371195)
文摘For any integer n ≥ 2, let P（n） be the largest prime factor of n. In this paper, we prove 1 This that the number of primes p 〈 x with P（p- 1） ≥ pC is more than （1 -c＋o（1））π（x） for 0 〈 c 〈 1/2 extends a recent result of Luca, Menares and Madariaga for1/4≤c≤1/2. We also pose two conjectures for further research.
基金Project supported by the Tian Yuan Item in the National Natural Science Foundation of China.
文摘Let P（x） denote the greatest prime factor of ∏<sub>x【n≤x+x<sup>1/2</sup></sub>n. In this paper, we shall prove that P（x）】x<sup>0.728</sup>holds true for sufficiently large x.
基金supported by the National Natural Science Foundation of China(Nos.11371195,11471017)the Youth Foundation of Mathematical Tianyuan of China(No.11126302)the Project of Graduate Education Innovation of Jiangsu Province(No.CXZZ12-0381)
文摘Let n = p1p2 ··· pk, where pi(1 ≤ i ≤ k) are primes in the descending order and are not all equal. Let Ωk(n) = P(p1 + p2)P(p2 + p3) ··· P(pk-1+ pk)P(pk+ p1), where P(n) is the largest prime factor of n. Define w0(n) = n and wi(n) = w(wi-1(n)) for all integers i ≥ 1. The smallest integer s for which there exists a positive integer t such thatΩs k(n) = Ωs+t k(n) is called the index of periodicity of n. The authors investigate the index of periodicity of n.
