Startseite Mathematik A preconditioned AOR iterative scheme for systems of linear equations with L-matrics
Artikel Open Access

A preconditioned AOR iterative scheme for systems of linear equations with L-matrics

  • Hongjuan Wang EMAIL logo
Veröffentlicht/Copyright: 31. Dezember 2019

Abstract

In this paper we investigate theoretically and numerically the new preconditioned method to accelerate over-relaxation (AOR) and succesive over-relaxation (SOR) schemes, which are used to the large sparse linear systems. The iterative method that is usually measured by the convergence rate is an important method for solving large linear equations, so we focus on the convergence rate of the different preconditioned iterative methods. Our results indicate that the proposed new method is highly effective to improve the convergence rate and it is the best one in three preconditioned methods that are revealed in the comparison theorems and numerical experiment.

MSC 2010: 15-xx; 15A06; 15A24

1 Introduction

With the development of natural and social sciences, we always encounter some big data problems which are related to the sparse linear equations. For instance, in numerical weather forecasting, simulated nuclear explosion, oil and gas resource development, partial differential equations are used to establish mathematical models, which generate large sparse linear equations by proper difference or finite element. However, the traditional Gaussian elimination method is no longer applicable because it requires a lot of storage space. So the iterative method is presented to solve the approximate solution of the large sparse linear equations, and some effective iterative schemes are developed, such as the Gauss-Seidel method, Jacobi method, AOR method, SOR and SOR-like method [1, 2] etc.

Usually the large sparse linear system can be expressed as:

Ax=b, (1)

where ARn×n, bRn are given and xRn should be solved. A can be expressed in terms of the identity matrix I, strictly lower and upper triangular matrices L and U, respectively, namely A = ILU. Then the iterative matrix of Gauss-Seidel method [3] for solving the linear system (1) is

H=(IL)1U. (2)

In order to improve convergence of the iterative method, AOR iterative scheme is demonstrated [4, 5, 6]. The iteration matrix of AOR is

Lrw=(IrL)1[(1w)I+(wr)L+wU], (3)

where w and r are real parameters with w ≠ 0. If w = r, it is SOR iterative scheme. When the spectral radius of iterative matrix is less than 1, the iterative method converges. The smaller spectral radius results in faster convergence speed of the iterative matrix.

In the calculation process, convergence is not only dependent on the iteration matrix and parameters in the iterative methods, but also closely related to the changes of the equations themselves. So we can multiply both sides of the system (1) by a nonsingular matrix to improve the efficiency of solving the equations. Then the original linear system (1) is equivalent to the following preconditioned linear system (e.g., see [7, 8, 9, 10, 11]):

PAx=Pb,

where P is a non-singular matrix. In order to increase calculate, the preconditioned matrix P can be adopted as different forms [12, 13, 14, 15, 16].

The following preconditioned matrix is proposed by Evans et al. [17]

P=I+S~,

where

S~=000000an100.

Then the system (1) is equivalent to the following preconditioned system:

A~x=b~, (4)
A~=(I+S~)A

and

b~=(I+S~)b.

Another preconditioned form is presented by Gunawardena et al. [18]

P=I+S¯,

where

S¯=0a120000a230000an1,n0000.

So the system (1) becomes the following:

A¯x=b¯, (5)

where A = (I + S)A and b = (I + S)b.

In the spirit of previous work, we in this paper consider the following preconditioned linear system:

Ax=b, (6)

where A′ = (I + S′)A and b′ = (I + S′)b with

S=S~+S¯=0a120000a230000an1,nan1000.

In the present work, we are studying the modified preconditioned method mentioned above via theoretical proof and numerical experiment. We describe the preconditioned approaches, including the AOR and SOR schemes in Section 2. Our results and discussions are presented in Section 3. Our conclusions are summarized in Section 4.

2 Methods

2.1 Preconditioned AOR scheme

In (4), Ã is

A~=D~L~U~,

where

D~=diag(1,1,,1,1a1nan1), (7)
L~=0a210a31a3200an1a12an2an1a1,n1an,n10, (8)
U~=U=0a12a13a1n0a23a2n0an1,n0. (9)

So the AOR scheme becomes

L~rw=(D~rL~)1[(1w)D~+(wr)L~+wU~]. (10)

In (5), A is

A¯=D¯L¯U¯,

where

D¯=diag(1a12a21,,1an1,nan,n1,1), (11)
L¯=0a21+a23a310an1,1+an1,nan1an1,2+an1,nan20an1an2an,n10, (12)
U¯=00a13+a12a23a1n+a12a2n00a2n+a23a3n000. (13)

Then the corresponding AOR scheme is

L¯rw=(D¯rL¯)1[(1w)D¯+(wr)L¯+wU¯]. (14)

In (6), the coefficient matrix can be stated

A=DLU,

where

D=1a12a211a23a321an1,nan,n11an1a1n, (15)
L=0a21+a23a310an1,1+an1,nan1an1,2+an1,nan200an2+an1a12an,n1+an1a1,n10, (16)
U=U¯=00a13+a12a23a1n+a12a2n00a2n+a23a3n000. (17)

Here AOR scheme becomes

Lrw=(DrL)1[(1w)D+(wr)L+wU]. (18)

2.2 Our lemma

Lemma 1

Let A and A ′ be the coefficient matrices of the linear system (1) and (6), respectively. If 0 ≤ rw ≤ 1 (w ≠ 0, r ≠ 1), A is an irreducible L-matrix with 0 < a1nan1 < 1 and 0 < ai,I + 1aI + 1,i < 1, i = 1, 2, ⋯, n – 1. (This condition implies A is irreducible.)

Then the iterative matrices Lrw and Lrw associated to the A OR method applied to the linear system (1) and (6), respectively, are nonnegative and irreducible.

Proof

From that A is a L-matrix (i.e., aij > 0; i = j = 1, ⋯, n and aij ⩽ 0, for all i, j = 1, 2, ⋯, n; ij [19]), we have L ≥ 0 is a strictly lower triangular matrix and U ≥ 0 is a strictly upper triangular matrix. So (IrL)–1 = I + rl + r2L2 + ⋯ + rn – 1 Ln – 1 ≥ 0.

By (3), we have

Lrw=(IrL)1[(1w)I+(wr)L+wU]=[I+rL+r2L2++rn1Ln1][(1w)I+(wr)L+wU]=(1w)I+(wr)L+wU+rL(1w)I+rL[(wr)L+wU]+(r2L2++rn1Ln1)[(1w)I+(wr)L+wU]=(1w)I+w(1r)L+wU+T,

where

T=rL[(wr)L+wU]+(r2L2++rn1Ln1)[(1w)I+(wr)L+wU]0.

So Lrw is nonnegative. Because 0 < ai,I + 1aI + 1,i < 1, i = 1, 2, ⋯, n – 1, A is irreducible (i.e., the directed graph of A is strongly connected). Thus, we can also get that (1 – w)I + w(1 – r)L + wU is irreducible when A is irreducible. So Lrw is irreducible.

As to Lrw , by (18), we have

Lrw=(DrL)1[(1w)D+(wr)L+wU]=(IrD1L)1[(1w)I+(wr)D1L+wD1U]=(1w)I+w(1r)D1L+wD1U+T,

where

T=rD1L[(wr)D1L+wD1U]+[r2(D1L)2++rn1(D1L)n1][(1w)I+(wr)D1L+wD1U]0.

and from D′ ≥ 0, L′ ≥ 0 and U′ ≥ 0, we can get Lrw0.

Let

C=L+U=00a1,n1+a12a2,n1a1n+a12a2na21+a23a310a2,n1+a23a3,n1a2n+a23a3nan1,1+an1,nan,1an1,2+an1,nan2000an2+an1a12an,n1+an1a1,n10.

Because of 0 < a1nan1 < 1 and 0 < ai,I+1aI+1,i < 1, i = 1, 2, ⋯, n – 1, there exist at least the following elements that are not equal to null in the matrix C:

ci,i+2=ai,i+2+ai,i+1ai+1,i+20,i=1,2,,n2,
cn1,1=an1,1+an1,nan10,

and

cn2=an2+an1a120.

This is to say that L′ + U′ is irreducible. w ≠ 0, r ≠ 1 and L′ + U′ is irreducible, So w(1 – r)D–1 L′ + wD–1 U′ is irreducible. From Lrw = (1 – w)I + w(1 – r)D–1 L′ + wD–1 U′ + T′ and T′ ≥ 0, we get Lrw is irreducible.

3 Results and discussion

Theorem 1

Let Lrw and Lrw be defined by (3) and (18), respectively. Under the hypotheses in Lemma 1, we have

  1. ρ(Lrw)<ρ(Lrw), if ρ(Lrw) < 1 ;

  2. ρ(Lrw)=ρ(Lrw), if ρ(Lrw) = 1;

  3. ρ(Lrw)>ρ(Lrw), if ρ(Lrw) > 1.

Proof

From Lemma 1, we know that Lrw and Lrw are nonnegative and irreducible matrices. Thus, from results (If A is a nonnegative and irreducible matrix, there exists a positive real eigenvalue that equals to its spectral radius ρ (A), and an eigenvector x > 0 corresponding to ρ(A).) in [20], so there is a positive vector x such thatLrwx = λ x, λ = ρ(Lrw),

[(1w)I+(wr)L+wU]x=λ(IrL)x. (19)

Therefore, for this x > 0,

Lrwxλx=(DrL)1[(1w)D+(wr)L+wUλ(DrL)]x. (20)

Based on (15), (16) and (17), we get that

DL=ILS¯L+S~S~U, (21)
U=S¯US¯+U. (22)

Because of

λ(DrL)x=λ(1r)Dx+λr(DL)x, (23)

we obtain the following formula from (21), (22), (23) and (20)

Lrwxλx=(DrL)1[(1w)D+(wr)(DI+L+S¯LS~+S~U)+w(S¯US¯+U)λ(1r)Dλr(ILS¯L+S~S~U)]x=(DrL)1[(1r)(1λ)(DI)+(wr)S¯L(wr)S~+(wr)S~U+wS¯UwS¯+λrS¯LλrS~+λrS~U]x.

From (19), we have

wUx=(λ1+w)x+(rwλr)Lx. (24)

Using (24), we get

Lrwxλx=(DrL)1[(1r)(1λ)(DI)(1r)(1λ)S~rS~U+λrS~U+(rwλr)S~L+(λ1)S¯]x.

Since L = 0, we can write as

Lrwxλx=(DrL)1[(1r)(1λ)(DI)(1r)(1λ)S~(1λ)S¯r(1λ)S~U]x. (25)

Because

DI=a12a21a23a32an1,nan,n1an1a1n,
S~U=0000000000000an1a12an1a13an1a1n, (26)

we have

DI0,S~0,S¯0,S~U0.

Let B = (D′–rL′) – 1[(1 – r)(D′ – I) – (1 – r)SrU]x, then B ≤0. So (25) becomes

Lrwxλx=(1λ)B.

At the same time, from the results (A is a nonnegative matrix, if αxAx for some nonnegative vector x, x ≠ 0, then αρ(A); if Axβx for some positive vector x, then ρ (A) ⩽ β. Furthermore, if A is irreducible and 0 ≠ αxAxβx for some nonnegative vector x, then αρ(A) ⩽ β and x i s a positive vector.) in [21], we can get the following results:

  1. If 0 < λ < 1, then ρ(Lrw)<λ=ρ(Lrw);

  2. If λ = 1, then ρ(Lrw)=λ=ρ(Lrw);

  3. λ > 1, then ρ(Lrw)>λ=ρ(Lrw).

Now the following theorem is shown to compare the convergence rate of the AOR iterative scheme with two different preconditioned methods.

Theorem 2

Let rw and Lrw be the iterative matrices of the A OR method defined by (10) and (18), respectively. If 0rw ≤ 1 (w ≠ 0, r ≠ 1), A is an irreducible L - matrix with 0 < a1nan1 < 1 and there exists a non-empty set of βN = {1, 2, ⋯, n – 1} such that

0<ai,i+1ai+1,i<1,iβ,ai,i+1ai+1,i=0,iNβ.

We obtain

  1. ρ(Lrw)<ρ(L~rw), if ρ(rw) < 1;

  2. ρ(Lrw)=ρ(L~rw), if ρ(rw) = 1;

  3. ρ(Lrw)>ρ(L~rw), if ρ(rw) > 1.

Proof

From Lemma 3.4. in [22] and Lemma 1, we know that rw and Lrw are nonnegative and irreducible matrices. So there exists a positive vector x such that rwx = λ x, λ = ρ(rw) (from results in [20].).

From (10), we have

(D~rL~)1[(1w)D~+(wr)L~+wU~]x=λx,

i.e.,

[(1w)D~+(wr)L~+wU~]x=λ(D~rL~)x. (27)
Lrwxλx=(DrL)1[(1w)D+(wr)L+wUλ(DrL)]x, (28)

where x is a positive vector.

Based on (7), (8) and (16), we get

DL=D~L~S¯L.

By (9) and (17), we can obtain

U=S¯U~S¯+U~.

From (27), we have

wU~=(λ1+w)D~+(rwλr)L~

i.e.,

λ(DrL)x=λ(1r)Dx+λr(DL)x,

(28) can be written as

Lrwxλx=(DrL)1[(1w)D+(wr)(DD~+L~+S¯L)+w(S¯U~S¯+U~)λ(1r)Dλr(D~L~S¯L)]x=(DrL)1[(1r)(1λ)(DD~)+(wr)S¯L+wS¯U~wS¯+λrS¯L]x.

We can get the following from (9) and (24)

Lrwxλx=(DrL)1[(1w)D+(wr)(DD~+L~+S¯L)+w(S¯U~S¯+U~)λ(1r)Dλr(D~L~+S¯L)]x=(DrL)1[(1r)(1λ)(DD~)+(wr)S¯L+wS¯U~wS¯+λrS¯L]x.

By (7) and (15), we have D′ – D~ ≤ 0. Let Q = (D′ – rL′) – 1 [(1 – r)(D′ – D~) – S]x. It is obvious that Q ≤ 0. The following proof is similar to Theorem 1.

Based on Theorem 3.5. in [22] and Theorem 2, we obtain the following corollary.

Corollary 1

Let Lrw, rw and Lrw be defined by (3), (10) and (18), respectively. Under the hypotheses in Theorem 4, we have

  1. ρ(Lrw)<ρ(L~rw)<ρ(Lrw), if ρ(Lrw) < 1;

  2. ρ(Lrw)=ρ(L~rw)=ρ(Lrw), if ρ(Lrw) = 1;

  3. ρ(Lrw)>ρ(L~rw)>ρ(Lrw), if ρ(Lrw) > 1.

If w = r in Corollary 1, we can obtain the results of SOR method, and if w = 1, r = 0, we can get the corresponding Jacobi results.

Theorem 3

Let Lrw and Lrw be defined by(14) and (18), respectively. under the conditions in Theorem 4, we have

  1. ρ(Lrw)<ρ(L¯rw), if ρ(Lrw) < 1;

  2. ρ(Lrw)=ρ(L¯rw), if ρ(Lrw) = 1;

  3. ρ(Lrw)>ρ(L¯rw), if ρ(Lrw) > 1.

Proof

From Lemma 4 in [23] and Lemma 1, it is clear that Lrw and Lrw are nonnegative andirreducible matrices. So there exists a positive vector x such that Lrwx = λ x, where λ = ρ(Lrw). From (11), (12), (15) and (16), the following equality is easily proved:

DL=D¯L¯+S~S~U

and

Lrwxλx=(DrL)1[(1w)D+(wr)L+wUλ(DrL)]x=(DrL)1[(1w)D+(wr)(DD¯+L¯S~+S~U)+wU¯λ(1r)Dλr(D¯L¯+S~S~U)]x=(DrL)1[(1w)D+(wr)(DD¯+L¯S~+S~U)+(λ1+w)D¯+(rwλr)L¯λ(1r)Dλr(D¯L¯+S~S~U)]x=(DrL)1[(1r)(1λ)(DD¯)+(w+rλr)S~+(λ1+w)S~D~+(rwλr)S~L~+(λrr)S~U]x,

where x is a positive vector.

Since ~D~ = and ~ = 0,

Lrwxλx=(DrL)1[(1r)(1λ)(DD¯)(1r)(1λ)S~r(1λ)S~U]x.

Let K = (D′–rL′)–1[(1 – r)(D′–D)–(1 – r)rU]x. Obviously, K ≤0. The following proof is similar to Theorem 1.

From Theorem 2 in [23 and Theorem 3], we have the following corollary.

Corollary 2

Let Lrw, Lrw and Lrw be defined by (3), (14) and (18), respectively. under the hypotheses, we get

  1. ρ(Lrw)<ρ(L¯rw)<ρ(Lrw), if ρ(Lrw) < 1;

  2. ρ(Lrw)=ρ(L¯rw)=ρ(Lrw), if ρ(Lrw) = 1;

  3. ρ(Lrw)>ρ(L¯rw)>ρ(Lrw), if ρ(Lrw) > 1.

Same as Corollary 1, Corollary 2 can also be applied to SOR and Jacobi iterative methods.

Remark 1

From these results, we can conclude that the spectral radius of our preconditioned AOR (SOR, Jacobi) iterative matrix is the smallest. It is to say that the convergence of our modified AOR (SOR, Jacobi) scheme is the fastest in the above three preconditioned methods.

4 Example

We show the numerical example to verify the theorems.

The coefficient matrix A of (1) is the following:

A=11n×1001(n1)×10013×1001101n×10+1113×10+21(n1)×10+21n×10+21(n1)×10+112×10+311(n1)×10+31n×10+313×10+11(n2)×10+(n1)1(n3)×10+(n1)11n×10+(n1)1051(n1)×10+n1(n2)×10+n12×10+n1.

By applying three preconditioned methods to the linear system, we can get Table 1, Table 2 and Table 3.

Table 1

Comparison of spectral radius of AOR scheme.

n r w ρ(Lrw) ρ(rw) ρ(Lrw) ρ(Lrw)
10 0.8 0.9 0.3696 0.1723 0.3690 0.1614
20 0.8 0.95 0.3340 0.1525 0.3337 0.1420
50 0.75 0.8 0.4507 0.3230 0.4506 0.3166
100 0.85 0.9 0.3518 0.2369 0.3517 0.2306

Table 2

Comparison of spectral radius of SOR scheme.

n r w ρ(Lrw) ρ(rw) ρ(Lrw) ρ(Lrw)
10 0.7 0.7 0.5302 0.3662 0.5298 0.3579
30 0.8 0.8 0.4388 0.2988 0.4387 0.2910
40 0.95 0.95 0.2739 0.1388 0.2737 0.1290

Table 3

Comparison of spectral radius of Jacobi scheme.

n r w ρ(B) ρ() ρ(B) ρ(B′)
20 0 1 0.4513 0.2131 0.4511 0.2042
60 0 1 0.4501 0.2824 0.4500 0.2769

Remark 2

From the tables, we can find that numerical results are in accordance with the above theorems. These results imply that the improved preconditioned method (I + S′) is the most effective to accelerate convergence of AOR (SOR, Jacobi) iterative scheme in these three preconditioned methods (I + ), (I + S) and (I + S′).

5 Conclusions

In this work, we study the improved preconditioned AOR (SOR, Jacobi) iterative scheme. In order to explore the most effective method to improve the convergence speed, we provide some comparison theorems and the numerical example in three preconditioned methods. Our main conclusions are summarized below.

  1. From the comparison theorems, we find that the spectral radius of our new preconditioned AOR (SOR, Jacobi) iterative matrix is less than 1, and it is the smallest in three different preconditioned methods. Our results suggest that the convergence speed of the improved preconditioned AOR (SOR, Jacobi) scheme is the fastest.

  2. Our numerical results indicate that the new preconditioned method is the most effective to accelerate convergence speed of AOR (SOR, Jacobi) iterative scheme.

Acknowledgements

This work was supported by the National Natural Science Foundation (Grant No. 11603004), Beijing Natural Science Foundation (Grant No. 1173010), and Beijing Education Commission Project (Grant No. KM201710015004).

References

[1] Ke Y.F., Ma C.F., SOR-like iteration method for solving absolute value equations, Appl. Math. Comput., 2017, 311, 195–202.10.1016/j.amc.2017.05.035Suche in Google Scholar

[2] Zhang C.Y., Xu F., Xu Z., Li J., General H-matrices and their Schur complements, Front. Math. China, 2014, 9, 1141–1168.10.1007/s11464-014-0395-1Suche in Google Scholar

[3] Edalatpour V., Hezari D., Salkuyeh D., A generalization of the Gauss–Seidel iteration method for solving absolute value equations, Appl. Math. Comput., 2017, 293, 156–167.10.1016/j.amc.2016.08.020Suche in Google Scholar

[4] Hadjimos A., Accelerated overrelaxation method, Math. Comp., 1978, 32, 149–157.10.1090/S0025-5718-1978-0483340-6Suche in Google Scholar

[5] Huang Z.G., Wang L.G, Xu Z., Cui J.J., Some new preconditioned generalized AOR methods for solving weighted linear least squares problems, Comp. Appl. Math., 2018, 37, 415–438.10.1007/s40314-016-0350-8Suche in Google Scholar

[6] Li C., A preconditioned AOR iterative method for the absolute value equations, Int. J. Comput. Methods, 2017, 14(2), 1750016.10.1142/S0219876217500165Suche in Google Scholar

[7] Saberi Najafi H., Edalatpanah S.A., Refahisheikhani A.H., An analytical method as a preconditioning modeling for systems of linear equations, Comp. Appl. Math., 2018, 37, 922–931.10.1007/s40314-016-0376-ySuche in Google Scholar

[8] Dai P., Li J., Li Y., Bai J., A general preconditioner for linear complementarity problem with an M-matrix, J. Comput. Appl. Math., 2017, 317, 100–112.10.1016/j.cam.2016.11.034Suche in Google Scholar

[9] Salkuyeh D.K., Hasani M., Beik F.P.A., On the preconditioned AOR iterative method for Z-matrices, Comp. Appl.Math., 2017, 36, 877–883.10.1007/s40314-015-0266-8Suche in Google Scholar

[10] Liu Q., Huang J., Zeng S., Convergence analysis of the two preconditioned iterative methods for M-matrix linear systems, J. Comput. Appl. Math., 2015, 281, 49–57.10.1016/j.cam.2014.11.034Suche in Google Scholar

[11] Saberi Najafi H., Edalatpanah S.A., A new family of (I+S)-type preconditioner with some applications, Comp. Appl. Math., 2015, 34, 917–931.10.1007/s40314-014-0161-8Suche in Google Scholar

[12] Yun J., Comparison results of the preconditioned AOR methods for L-matrices, Appl. Math. Comput., 2011, 218, 3399–3413.10.1016/j.amc.2011.08.085Suche in Google Scholar

[13] Yuan J., Zontini D., Comparison theorems of preconditioned Gauss-Seidel methods for M-matrices, Appl. Math. Comput.,2012, 219, 1947–1957.10.1016/j.amc.2012.08.037Suche in Google Scholar

[14] Wang H., Li Y., A new preconditioned AOR iterative method for M-matrices, J. Comput. Appl. Math., 2009, 229, 47–56.10.1007/s12190-010-0423-6Suche in Google Scholar

[15] Wu S., Li C., A note on parameterized block triangular preconditioners for generalized saddle point problems, Appl. Math. Comput., 2013, 219, 7907–7916.10.1016/j.amc.2013.01.040Suche in Google Scholar

[16] Wu S., Li C., Eigenvalue estimates of indefinite block triangular preconditioner for saddle point problems, J. Comput. Appl. Math., 2014, 260, 349–355.10.1016/j.cam.2013.10.009Suche in Google Scholar

[17] Evans D.J., Martins M.M., Trigo M.E., The AOR iterative method for new preconditioned linear systems, J. Comput. Appl. Math., 2001, 132, 461–466.10.1016/S0377-0427(00)00447-7Suche in Google Scholar

[18] Gunawardena A.D., Jain S.K., Snyder L., Modified iteration methods for consistent linear systems, Linear Algebra Appl.,1991, 154, 123–143.10.1016/0024-3795(91)90376-8Suche in Google Scholar

[19] Young D.M., Iterative Solution of Large Linear Systems, Academic Press, New York, London, 1971.Suche in Google Scholar

[20] Varga R.S., Matrix Iterative Analysis, Prentice-Hall, Englewood Cliffs, New York, 1962.Suche in Google Scholar

[21] Berman A., Plemmons R.J., Nonnegative Matrices in the Mathematical Sciences, SIAM, Philadelphia, PA, 1994.10.1137/1.9781611971262Suche in Google Scholar

[22] Yun J.H., A note on precondetioned AOR method for L-matrices, J. Comput. Appl. Math., 2008, 220, 13–16.10.1016/j.cam.2007.07.009Suche in Google Scholar

[23] Li Y.T., Li C., Wu S., Improving AOR method for consistent linear systems, Appl. Math. Comput., 2007, 186, 379–388.10.1016/j.amc.2006.07.097Suche in Google Scholar

Received: 2018-10-24
Accepted: 2019-10-21
Published Online: 2019-12-31

© 2019 Hongjuan Wang, published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 Public License.

Artikel in diesem Heft

  1. Regular Articles
  2. On the Gevrey ultradifferentiability of weak solutions of an abstract evolution equation with a scalar type spectral operator of orders less than one
  3. Centralizers of automorphisms permuting free generators
  4. Extreme points and support points of conformal mappings
  5. Arithmetical properties of double Möbius-Bernoulli numbers
  6. The product of quasi-ideal refined generalised quasi-adequate transversals
  7. Characterizations of the Solution Sets of Generalized Convex Fuzzy Optimization Problem
  8. Augmented, free and tensor generalized digroups
  9. Time-dependent attractor of wave equations with nonlinear damping and linear memory
  10. A new smoothing method for solving nonlinear complementarity problems
  11. Almost periodic solution of a discrete competitive system with delays and feedback controls
  12. On a problem of Hasse and Ramachandra
  13. Hopf bifurcation and stability in a Beddington-DeAngelis predator-prey model with stage structure for predator and time delay incorporating prey refuge
  14. A note on the formulas for the Drazin inverse of the sum of two matrices
  15. Completeness theorem for probability models with finitely many valued measure
  16. Periodic solution for ϕ-Laplacian neutral differential equation
  17. Asymptotic orbital shadowing property for diffeomorphisms
  18. Modular equations of a continued fraction of order six
  19. Solutions with concentration and cavitation to the Riemann problem for the isentropic relativistic Euler system for the extended Chaplygin gas
  20. Stability Problems and Analytical Integration for the Clebsch’s System
  21. Topological Indices of Para-line Graphs of V-Phenylenic Nanostructures
  22. On split Lie color triple systems
  23. Triangular Surface Patch Based on Bivariate Meyer-König-Zeller Operator
  24. Generators for maximal subgroups of Conway group Co1
  25. Positivity preserving operator splitting nonstandard finite difference methods for SEIR reaction diffusion model
  26. Characterizations of Convex spaces and Anti-matroids via Derived Operators
  27. On Partitions and Arf Semigroups
  28. Arithmetic properties for Andrews’ (48,6)- and (48,18)-singular overpartitions
  29. A concise proof to the spectral and nuclear norm bounds through tensor partitions
  30. A categorical approach to abstract convex spaces and interval spaces
  31. Dynamics of two-species delayed competitive stage-structured model described by differential-difference equations
  32. Parity results for broken 11-diamond partitions
  33. A new fourth power mean of two-term exponential sums
  34. The new operations on complete ideals
  35. Soft covering based rough graphs and corresponding decision making
  36. Complete convergence for arrays of ratios of order statistics
  37. Sufficient and necessary conditions of convergence for ρ͠ mixing random variables
  38. Attractors of dynamical systems in locally compact spaces
  39. Random attractors for stochastic retarded strongly damped wave equations with additive noise on bounded domains
  40. Statistical approximation properties of λ-Bernstein operators based on q-integers
  41. An investigation of fractional Bagley-Torvik equation
  42. Pentavalent arc-transitive Cayley graphs on Frobenius groups with soluble vertex stabilizer
  43. On the hybrid power mean of two kind different trigonometric sums
  44. Embedding of Supplementary Results in Strong EMT Valuations and Strength
  45. On Diophantine approximation by unlike powers of primes
  46. A General Version of the Nullstellensatz for Arbitrary Fields
  47. A new representation of α-openness, α-continuity, α-irresoluteness, and α-compactness in L-fuzzy pretopological spaces
  48. Random Polygons and Estimations of π
  49. The optimal pebbling of spindle graphs
  50. MBJ-neutrosophic ideals of BCK/BCI-algebras
  51. A note on the structure of a finite group G having a subgroup H maximal in 〈H, Hg
  52. A fuzzy multi-objective linear programming with interval-typed triangular fuzzy numbers
  53. Variational-like inequalities for n-dimensional fuzzy-vector-valued functions and fuzzy optimization
  54. Stability property of the prey free equilibrium point
  55. Rayleigh-Ritz Majorization Error Bounds for the Linear Response Eigenvalue Problem
  56. Hyper-Wiener indices of polyphenyl chains and polyphenyl spiders
  57. Razumikhin-type theorem on time-changed stochastic functional differential equations with Markovian switching
  58. Fixed Points of Meromorphic Functions and Their Higher Order Differences and Shifts
  59. Properties and Inference for a New Class of Generalized Rayleigh Distributions with an Application
  60. Nonfragile observer-based guaranteed cost finite-time control of discrete-time positive impulsive switched systems
  61. Empirical likelihood confidence regions of the parameters in a partially single-index varying-coefficient model
  62. Algebraic loop structures on algebra comultiplications
  63. Two weight estimates for a class of (p, q) type sublinear operators and their commutators
  64. Dynamic of a nonautonomous two-species impulsive competitive system with infinite delays
  65. 2-closures of primitive permutation groups of holomorph type
  66. Monotonicity properties and inequalities related to generalized Grötzsch ring functions
  67. Variation inequalities related to Schrödinger operators on weighted Morrey spaces
  68. Research on cooperation strategy between government and green supply chain based on differential game
  69. Extinction of a two species competitive stage-structured system with the effect of toxic substance and harvesting
  70. *-Ricci soliton on (κ, μ)′-almost Kenmotsu manifolds
  71. Some improved bounds on two energy-like invariants of some derived graphs
  72. Pricing under dynamic risk measures
  73. Finite groups with star-free noncyclic graphs
  74. A degree approach to relationship among fuzzy convex structures, fuzzy closure systems and fuzzy Alexandrov topologies
  75. S-shaped connected component of radial positive solutions for a prescribed mean curvature problem in an annular domain
  76. On Diophantine equations involving Lucas sequences
  77. A new way to represent functions as series
  78. Stability and Hopf bifurcation periodic orbits in delay coupled Lotka-Volterra ring system
  79. Some remarks on a pair of seemingly unrelated regression models
  80. Lyapunov stable homoclinic classes for smooth vector fields
  81. Stabilizers in EQ-algebras
  82. The properties of solutions for several types of Painlevé equations concerning fixed-points, zeros and poles
  83. Spectrum perturbations of compact operators in a Banach space
  84. The non-commuting graph of a non-central hypergroup
  85. Lie symmetry analysis and conservation law for the equation arising from higher order Broer-Kaup equation
  86. Positive solutions of the discrete Dirichlet problem involving the mean curvature operator
  87. Dislocated quasi cone b-metric space over Banach algebra and contraction principles with application to functional equations
  88. On the Gevrey ultradifferentiability of weak solutions of an abstract evolution equation with a scalar type spectral operator on the open semi-axis
  89. Differential polynomials of L-functions with truncated shared values
  90. Exclusion sets in the S-type eigenvalue localization sets for tensors
  91. Continuous linear operators on Orlicz-Bochner spaces
  92. Non-trivial solutions for Schrödinger-Poisson systems involving critical nonlocal term and potential vanishing at infinity
  93. Characterizations of Benson proper efficiency of set-valued optimization in real linear spaces
  94. A quantitative obstruction to collapsing surfaces
  95. Dynamic behaviors of a Lotka-Volterra type predator-prey system with Allee effect on the predator species and density dependent birth rate on the prey species
  96. Coexistence for a kind of stochastic three-species competitive models
  97. Algebraic and qualitative remarks about the family yy′ = (αxm+k–1 + βxmk–1)y + γx2m–2k–1
  98. On the two-term exponential sums and character sums of polynomials
  99. F-biharmonic maps into general Riemannian manifolds
  100. Embeddings of harmonic mixed norm spaces on smoothly bounded domains in ℝn
  101. Asymptotic behavior for non-autonomous stochastic plate equation on unbounded domains
  102. Power graphs and exchange property for resolving sets
  103. On nearly Hurewicz spaces
  104. Least eigenvalue of the connected graphs whose complements are cacti
  105. Determinants of two kinds of matrices whose elements involve sine functions
  106. A characterization of translational hulls of a strongly right type B semigroup
  107. Common fixed point results for two families of multivalued A–dominated contractive mappings on closed ball with applications
  108. Lp estimates for maximal functions along surfaces of revolution on product spaces
  109. Path-induced closure operators on graphs for defining digital Jordan surfaces
  110. Irreducible modules with highest weight vectors over modular Witt and special Lie superalgebras
  111. Existence of periodic solutions with prescribed minimal period of a 2nth-order discrete system
  112. Injective hulls of many-sorted ordered algebras
  113. Random uniform exponential attractor for stochastic non-autonomous reaction-diffusion equation with multiplicative noise in ℝ3
  114. Global properties of virus dynamics with B-cell impairment
  115. The monotonicity of ratios involving arc tangent function with applications
  116. A family of Cantorvals
  117. An asymptotic property of branching-type overloaded polling networks
  118. Almost periodic solutions of a commensalism system with Michaelis-Menten type harvesting on time scales
  119. Explicit order 3/2 Runge-Kutta method for numerical solutions of stochastic differential equations by using Itô-Taylor expansion
  120. L-fuzzy ideals and L-fuzzy subalgebras of Novikov algebras
  121. L-topological-convex spaces generated by L-convex bases
  122. An optimal fourth-order family of modified Cauchy methods for finding solutions of nonlinear equations and their dynamical behavior
  123. New error bounds for linear complementarity problems of Σ-SDD matrices and SB-matrices
  124. Hankel determinant of order three for familiar subsets of analytic functions related with sine function
  125. On some automorphic properties of Galois traces of class invariants from generalized Weber functions of level 5
  126. Results on existence for generalized nD Navier-Stokes equations
  127. Regular Banach space net and abstract-valued Orlicz space of range-varying type
  128. Some properties of pre-quasi operator ideal of type generalized Cesáro sequence space defined by weighted means
  129. On a new convergence in topological spaces
  130. On a fixed point theorem with application to functional equations
  131. Coupled system of a fractional order differential equations with weighted initial conditions
  132. Rough quotient in topological rough sets
  133. Split Hausdorff internal topologies on posets
  134. A preconditioned AOR iterative scheme for systems of linear equations with L-matrics
  135. New handy and accurate approximation for the Gaussian integrals with applications to science and engineering
  136. Special Issue on Graph Theory (GWGT 2019)
  137. The general position problem and strong resolving graphs
  138. Connected domination game played on Cartesian products
  139. On minimum algebraic connectivity of graphs whose complements are bicyclic
  140. A novel method to construct NSSD molecular graphs
Heruntergeladen am 24.12.2025 von https://www.degruyterbrill.com/document/doi/10.1515/math-2019-0125/html?lang=de
Button zum nach oben scrollen