Dear Label_Name,

Greetings! I hope you are well.

I am writing on behalf of an international publishing house, Science and Education Publishing, USA (http://www.sciepub.com).

Science and Education Publishing (SciEP) is a multidisciplinary open access publisher of Journals covering the fields of Science, Technology and Medicine. All SciEP publications are subject to high-quality peer review, editorial and production processes and are freely available online.

Welcome to the April, 2013 edition of SciEP newsletter, providing monthly summaries of articles on science & education related topics of interest to scientist and professionals. The mission of our journals is to provide an open access forum for publishing new findings on issues pertinent to scientific and academic field. We also invite you to submit original research papers, review articles, short reports, or case studies are considered for publication in our Multidisciplinary Journals.

American Journal of Public Health Research
DOI: 10.12691/ajphr-1-1-3

The Implementation of a Tele-Homecare System with Service Oriented Architecture and HL7 Message Transmission Standard
Ching-Sung Wang

American Journal of Medical and Biological Research
DOI: 10.12691/ajmbr-1-1-2

The Influence of Ethanol on Pyruvate Kinases Activity in Vivo, in Vitro, in Silico
Lelevich Sergey Vladimirovich, Khrustalev Vladislav Victorovich, Barkovsky Eugene Victorovich, Shedogubova Tatyana Aleksandrovna

American Journal of Medical Sciences and Medicine
DOI: 10.12691/ajmsm-1-1-1

Clinical and Histological Features in Wegener Granulomatosis
Li Cavoli Gioacchino, Passantino Rita, Bono Luisa, Tortorici Calogera, Ferrantelli Angelo, Giammarresi Carlo, Rotolo Ugo

American Journal of Infectious Diseases and Microbiology
DOI: 10.12691/ajidm-1-1-2

The Curse of Lymphatic Filariasis: Would the Continual Use of Diethylcarbamazine Eliminate this Scourge in Papua New Guinea?
Anne Lanham, Lillian Mwanri

We have released issues of some journals on February 2013.
American Journal of Public Health Research
American Journal of Medical Sciences and Medicine
American Journal of Medical and Biological Research
American Journal of Pharmacological Sciences
American Journal of Clinical Medicine Research
American Journal of Nursing Research
American Journal of Cancer Prevention
American Journal of Medicine Studies
American Journal of Infectious Diseases and Microbiology
American Journal of Cardiovascular Disease Research
American Journal of Biomedical Research
American Journal of Mechanical Engineering
American Journal of Microbiological Research
Journal of Preventive Medicine
American Journal of Food and Nutrition
American Journal of Hypertension Research
American Journal of Sports Science and Medicine
Journal of Cancer Research and Treatment
American Journal of Zoological Research
Journal of Biomedical Engineering and Technology
American Journal of Microbiological Research
Biomedical Science and Engineering

We are pleased to announce that submissions are now being accepted for peer review for all the journals across all our subject areas in SciEP.

Please submit your manuscript via our online submission system:
http://www.sciepub.com/author/signin

To unsubscribe from our mailing list, please click on the following link: unsubscribe

I am looking forward to hearing from you.

Kind regards,

David Rain
Email:join@sciepub.com
Science and Education Publishing (http://www.sciepub.com)

The Viscosity Iterative Algorithms for the Implicit Double Midpoint Rule of Nonexpansive Mappings in Hilbert Spaces

John T Mendy

University of the Gambia, Brikama Campus, Gambia

Abstract: In this paper, we study the viscosity iterative algorithms for the implicit double midpoint rule in real Hilbert space and prove strong convergence of the sequence {un} to a fixed point of T. As an application we employ our method to obtain an application of it in convex minimization and the solution of Fredholm type of integral equations.

Keywords: viscosity, implicit double midpoint, hilbert space, Fredohlm integral

Received April 11, 2020; Revised May 13, 2020; Accepted May 20, 2020

Citation: John T Mendy, The Viscosity Iterative Algorithms for the Implicit Double Midpoint Rule of Nonexpansive Mappings in Hilbert Spaces. American Journal of Mathematical Analysis, 8 (1). 1-8. January 2020. doi:10.12691/ajma-8-1-1

1. Introduction

Let be a Hilbert space, be a nonexpansive mapping and be a contraction. The viscosity approximation method for nonexpansive mapping in Hilbert spaces was introduced by Moudafi [26] by the following iterative method:

Let be a closed convex subset of Hilbert space H. Assume that is a contraction and is a nonexpansive mapping. For given the sequence defined by

[picture] | (1.1)

converges strongly to a fixed point of under certain conditions, which is a solution to the variational inequality

Moudafi's generalizations are called viscosity approximations. Viscosity approximation methods have been extensively employed in the literature to obtain strong convergence results (cf. [11,21,28,30,34] and references therein).

In 2004, Xu [32] extended the result of Moudafi [26] to uniformly smooth Banach spaces and obtained strong convergence theorem. For related work, see [7,16,37].

In 2006, Marino and Xu [38] introduced the following iterative scheme based on viscosity approximation method, for fixed point problem for a nonexpansive mapping on :

[picture] | (1.2)

where is a contraction mapping on with constant , is a strongly positive self-adjoint bounded linear operator on with constant and . They proved that the sequence generated by 1.2 converge strongly to the unique solution of the variational inequality

[picture] | (1.3)

which is the optimality condition for the minimization problem

[picture] | (1.4)

where is the potential function for .

The implicit midpoint rule is one of the powerful numerical methods for solving ordinary differential equations and differential algebraic equations. For related works, we refer to [6,39,40,41,42,43,44] and the references cited therein. For instance, consider the initial value problem for the differential equation with the initial condition , where f is a continuous function from to . The implicit midpoint rule in which generates a sequence by the following the recurrence relation

[picture] | (1.5)

In 2014, implicit midpoint rule has been extended by Alghamdi et al. [45] to nonexpansive mappings, which generates a sequence by the following implicit iterative scheme:

[picture] | (1.6)

In 2015, Xu et al. [34] extended (1.1) and obtained the following Viscosity implicit mid point method:

Theorem 1.1. Let be a Hilbert space, a closed convex subset of a nonexpansive mapping with and a contraction with coefficient . For givin the sequence generated by

[picture] | (1.7)

satisfying the following conditions:

C1:

C2:

C3: or

Then the sequence converges in norm to a fixed point of which is also the unique solution of the variational inequality

Later, Ke and Ma [21] and Cai et al. [11] generalized Theorem 1.1 in the setting of Hilbert space. They proposed the following theorems.

Theorem 1.2. [Ke and Ma] Let be a nonempty closed convex subset of the real Hilbert space . Let be a nonexpansive mapping with and be a contraction with coefficient . Pick any , let be a sequence generated by

[picture] | (1.8)

where satisfying certain conditions, then the sequence converges strongly to a fixed point of the nonexpansive mapping which is also the unique solution of the variational inequality

Theorem 1.3. [Ke and Ma] Let be a nonempty closed convex subset of the real Hilbert space . Let be a nonexpansive mapping with and be a contraction with coefficient . Pick any , let be a sequence generated by.

[picture] | (1.9)

where satisfying certain conditions, then the sequence converges strongly to a fixed point of the nonexpansive mapping which is also the unique solution of the variational inequality

Recently, Motivated by Xu et al. [34], Tang and Bao [30] considered the following result:

Theorem 1.4. Let be a nonempty closed uniformly convex and -uniformly smooth Banach space with dual Let be a -Lipschitz continuous monotone mapping such that For given the sequence defined by

where is the normalized duality mapping. Suppose that then the sequence converges strongly to an element

Of recently many work has not yet been done for viscosity implicit double midpoint rule (VIDMR). The recent work done for (VIDMR) was done by Shrijana Dhakal and Wutiphol Sintunavarat in 2019 where they defined the sequence in the following theorem.

Theorem 1.5. Shrijana Dhakal and Wutiphol Sintunavarat [46]. Let be a nonempty closed convex subset of a real Hilbert space be nonexpansive mapping with , and be contraction mapping with the contractive constant . Define a sequence by the following viscosity method for implicit double midpoint rule (VIDMR) as follows:

[picture] | (1.10)

where an for all and satisfies the following conditions:

(i):

(ii):

Then, the sequence converges to a fixed point of which is also the unique solution

[picture] | (1.11)

Motivated by Xu et al. [34], Tang and Bao [30], Shrijana Dhakal and Wutiphol Sintu-navarat [46] and others, we consider viscosity iterative algorithms for the implicit double midpoint rule for nonexpansion mapping in real Hilbert space. Applications to convex minimization problem and nonlinear Fredholm integral equations are included. The results presented in the paper extend and improve some recent results announced in the current literature.

2. Preliminary Notes

In the sequel, we always assume that is a real Hilbert space and is a nonempty, closed, and convex subset of . The nearest point projection from onto C, PC, is defined by

[picture] | (2.1)

Namely, is the only point in that minimizes the objective over and is characterized as follows:

[picture] | (2.2)

Mapping is said to be nonexpansive if

[picture] | (2.3)

We use to denote the set of fixed points of A mapping is said to be contractive if there exists a constant a such

[picture] | (2.4)

for all . In this case, is called contraction.

Lemma 2.1. [29]. Let be a sequence of nonnegative real numbers satisfying the following relation:

where and are real sequences such that

(i)

(ii)

Then the sequence converges to 0.

3. Main Results

Theorem 3.1. Let be a closed convex subset of a Hilbert space a nonexpansive mapping with , and a contraction with coefficient a . Let be generated by the following viscosity implicit double midpoint rule (VIDMR):

[picture] | (3.1)

where is a sequence in such that:

(A1)

(A2)

(A3)

Then converges strongly to a fixed point of which is also the unique solution of the following variational inequality:

Proof. The proof is in five stages.

Step 1: We prove that is bounded.

Fixing any , we have

It then follows that

Therefore

Consequently we have

By induction, it is easy to see that

Hence is bounded for all .

Step 2: We now show that

where , then we have

Therefore we have

Hence from lemma 2.1 . This implies that as

Step 3: We now show that This follows from the argument below

It now follows that

Step 4: Again we prove that

[picture] | (3.2)

where is the unique fixed point of the contraction , that is . Since the sequence is bounded, then there exist a subsequence of such that converges weakly to . Thus

[picture] | (3.3)

Since then by 2.2, 3.2 and 3.3, we concludes that

[picture] | (3.4)

Step 5: We now prove that as

Thus, we have the following

Therefore from lemma 2.1, we can see that and

Hence we can conclude that . This completes the proof.

Theorem 3.2. Let be a closed convex subset of a Hilbert space a nonexpansive mapping with , and a contraction with coefficient a . Let be a constant. Let be generated by the following viscosity implicit double midpoint rule (VIDMR):

where is a sequence in such that:

(A1)

(A2)

(A3)

Then converges strongly to a fixed point of , which is also the unique solution of the following variational inequality:

Corollary 3.3. Let be a closed convex subset of a Hilbert space a nonexpansive mapping with , and a contraction with coefficient a . Let be a constant. Let be generated by the following viscosity implicit double midpoint rule (VIDMR):

[picture] | (3.5)

where is a sequence in such that: Then converges strongly to a fixed point of , which is also the unique solution of the following variational inequality:

Here we assumed

Corollary 3.4. Let be a closed convex subset of a Hilbert space a nonexpansive mapping with , and a contraction with coefficient a . Let be generated by the following viscosity implicit double midpoint rule (VIDMR):

[picture] | (3.6)

where is a sequence in such that:

(A1):

(A2):

(A3):

Then converges strongly to a fixed point of , which is also the unique solution of the following variational inequality:

4. Application to Convex Minimization Problems

In this section, we study the problem of finding a minimizer of a convex function defined from Hilbert space

The following basic results are well known.

Remark 4.1. It is well known that if be a real-valued differentiable convex function and , then the point is a minimizer of on if and only if .

Definition 4.2. A function is said to be strongly convex if there exists such that for every with and , the following inequality holds:

[picture] | (4.1)

Lemma 4.3. Let be normed linear space and a real-valued differentiable convex function. Assume that is strongly convex. Then the differential map is strongly monotone, i.e., there exists a positive constant such that

[picture] | (4.2)

We now prove the following theorem.

Theorem 4.4. Let be a closed convex subset of a Hilbert space a nonexpansive mapping with , and a contraction with coefficient a . Let be generated by the following viscosity implicit double midpoint rule (VIDMR):

[picture] | (4.3)

where is a sequence in with conditions A1, A2 and A3, then converges strongly to a fixed point of , which is also the unique solution of the following variational inequality:

Proof. Since is nonempty closed convex, it follows that has a unique minimizer characterized by (Remark 4.1). Finally, from Lemma 4.3 and the fact that the differential map is contraction with a with a contraction coefficient , then the proof follows from Theorem 3.1.

5. Fredholm Integral Equation

Let be space of square integrable function endowed with inner product Now we discuss the solution of following Fredholm integral equation:

[picture] | (5.1)

and suppose that the following conditions hold: where and To obtain our claim, we consider the followings assumptions:

(A1) The functions are continuous.

(A2) is Lipschitz continuous, that is, for all

[picture] | (5.2)

(A3) is continuous for all where :

(A4) and

Now, we consider the mapping defined as

[picture] | (5.3)

It is easy to observe that is a nonexpansive mapping. For this, for every

This implies that

and is a nonexpansive mapping. Define

[picture] | (5.4)

where is sufficiently large, then is a closed ball of of radius with center at origin. It can be easily seen that . From Theorem in [8], operator has a fixed point in and this fixed point of operator is a solution of nonlinear integral equation 5.1.

Theorem 5.1. Let be a Hilbert space defined above and be a operator defined in (5.3). Let be a contraction with coefficient For arbitrary given define the sequence as follows:

[picture] | (5.5)

where is an identity operator and the sequences is in the interval satisfying the following conditions

(A1)

(A2)

(A3)

then the sequence converges weakly to the solution of nonlinear integral equation (5.1) and the proof is the required conclusion of Theorem 3.1.

Example 5.2. Consider the following integral equation:

[picture] | (5.6)

The above integral equation is a particular case of 5.1 with

For any and , we have

[picture] | (5.7)

[picture] | (5.8)

It can be easily seen that is a continuous function. Thus, integral equation 5.6 has a solution. It can be seen that is a solution of 5.6.

Acknowledgements

The authors thank the referees for their helping comments, which notably improved the presentation of this paper.

The authors also wish to acknowledge the financial support by the university of the Gambia for supporting this project.

Disclosure Statement

No potential conflict of interest was reported by the authors.

References

[1]   | D.H. Ackley, G.E. Hinton and T.J. Sejnowski, A learning algorithm for Boltzmann machine, Cognitive Science, 9 (1985), 147-169.
[2]   | Tan, Kok-Keong and Xu, Hong Kun. Approximating fixed points of nonexpansive mappings by the Ishikawa iteration process, Journal of Mathematical Analysis and Applications, volume 178, 1993, pages 301-308.
[3]   | C. E. Chidume, Geometric Properties of Banach spaces and Nonlinear Iterations, Springer Verlag, 2009.
[4]   | Agarwal, Ravi P. and Meehan, Maria and O'Regan, DonalFixed point theory and applications, Cambridge Tracts in Mathematics, volume 141, 2001.
[5]   | Alber, Ya I Metric and generalized projection operators in Banach spaces: properties and applications, Lecture Notes in Pure and Applied Mathematics pages 15-50, 1996.
[6]   | G. Bader, P. Deuflhard: A semi-implicit mid-point rule for stiff systems of ordinary differential equations, Numer. Math., 41 (1983) 373-398.
[7]   | Berinde, Vasile I terative approximation of fixed points, Lecture Notes in Mathematics, volume 1912, Springer, Berlin, 2007, 978-3-540-72233-5; 3-540-72233-5.
[8]   | Browder, Felix Nonlinear mappings of nonexpansive and accretive type in Banach spaces, Bulletin of the American Mathematical Society, volume 73, 1967.
[9]   | Browder, Felix E Nonlinear operators and nonlinear equations of evolution in Banach spaces, V, 1976
[10]   | Cai, Gang and Shehu, Yekini and Iyiola, Olaniyi Samuel. Modified viscosity implicit rules for nonexpansive mappings in Hilbert spaces, Journal of Fixed Point Theory and Applications, volume 19, 2017.
[11]   | Cai, Gang and Shehu, Yekini and Iyiola, Olaniyi Samuel. Strong convergence results for variational inequalities and fixed point problems using modified viscosity implicit rule, Numerical Algorithms, volume 77, 2018.
[12]   | Chidume, C. E. An approximation method for monotone Lipschitzian operators in Hilbert spaces, Australian Mathematical Society. Journal. Series A. Pure Mathematics and Statistics, volume 41, 1986.
[13]   | Chidume, C. E. I terative approximation of fixed points of Lipschitzian strictly pseudocontractive mappings, Proceedings of the American Mathematical Society, volume 99, 1987.
[14]   | Chidume, C. E. and Osilike, M. O. I terative solutions of nonlinear accretive operator equations in arbitrary Banach spaces, Nonlinear Analysis. Theory, Methods & Applications. An International Multidisciplinary Journal, volume 36, 1999, pages 863-872.
[15]   | Chidume, C. E. and Zegeye, H. Approximation of solutions of nonlinear equations of monotone and Hammerstein type volume 82, Applicable Analysis. An International Journal, 2003m pages 747-758.
[16]   | Chidume, Charles Geometric properties of Banach spaces and nonlinear iterations, Lecture Notes in Mathematics, Springer-Verlag London, Ltd., London, 2009.
[17]   | Chidume, C. E. and Djitté, N. Strong convergence theorems for zeros of bounded maximal monotone nonlinear operators, Abstract and Applied Analysis, 2012.
[18]   | Chidume, Charles E. and Idu, Kennedy O. Approximation of zeros of bounded maximal monotone mappings, solutions of Hammerstein integral equations and convex minimization problems, Fixed Point Theory and Applications, 2016.
[19]   | Ibaraki, Takanori and Takahashi, Wataru. A new projection and convergence theorems for the projections in Banach spaces, Journal of Approximation Theory volume 149, 2007, pages 1-14.
[20]   | Kato, Tosio. Nonlinear semigroups and evolution equations, Journal of the Mathematical Society of Japan, volume 19, 1967, pages 508-520.
[21]   | Ke, Yifen and Ma, Changfeng The generalized viscosity implicit rules of nonexpansive mappings in Hilbert spaces, Fixed Point Theory and Applications, 2015.
[22]   | Khorasani, Sina and Adibi, Ali. Analytical solution of linear ordinary differential equations by differential transfer matrix method, Electronic Journal of Differential Equations, 2003, pages 79.
[23]   | Martin, Robert H. Nonlinear operators and differential equations in Banach spaces, 1976.
[24]   | Martin, Jr., R. H. A global existence theorem for autonomous differential equations in a Banach space, Proceedings of the American Mathematical Society, volume 26, 1970, pages 307-314.
[25]   | Minty, George J. Monotone (nonlinear) operators in Hilbert space, Duke Mathematical Journal, volume 29, 1962, pages 341-346.
[26]   | Moudafi, A. Viscosity approximation methods for fixed-points problems, Journal of Mathematical Analysis and Applications, volume 241, 2000, pages 46-55.
[27]   | Ray, William O An elementary proof of surjectivity for a class of accretive operators, Proceedings of the American Mathematical Society, volume 75, 1979, pages 255-258.
[28]   | Shukla, Rahul and Pant, Rajendra. Approximating solution of split equality and equilibrium problems by viscosity approximation algorithms, Computational and Applied Mathematics, pages 1-22, 2018, Springer.
[29]   | Tan, Kok-Keong and Xu, Hong Kun. Approximating fixed points of nonexpansive mappings by the Ishikawa iteration process, Journal of Mathematical Analysis and Applications, volume 178, 1993, pages 301-308.
[30]   | Tang, Yan and Bao, Zhiqing. New semi-implicit midpoint rule for zero of monotone mappings in Banach spaces, Numerical Algorithms, pages 1-26, 2018, Springer.
[31]   | Turkyilmazoglu, Mustafa . Approximate analytical solution of the nonlinear system of differential equations having asymptotically stable equilibrium, Univerzitet u Nišu. Prirodno-Matematički Fakultet. Filomat, volume 31, 2017, pages 2633-2641.
[32]   | H.K. Xu: Viscosity approximation methods for nonexpansive mappings, J. Math. Anal. Appl., 298(2004) 279-291
[33]   | Xu, H. K. An iterative approach to quadratic optimization, Journal of Optimization Theory and Applications, volume 116, 2003, pages 659-678.
[34]   | Xu, Hong-Kun and Alghamdi, Maryam A. and Shahzad, Naseer. The viscosity technique for the implicit midpoint rule of nonexpansive mappings in Hilbert spaces, Fixed Point Theory and Applications, 2015,
[35]   | Zegeye, Habtu. Strong convergence theorems for maximal monotone mappings in Banach spaces, Journal of Mathematical Analysis and Applications, volume 343, 2008, pages 663-671.
[36]   | V. Berinde: Iterative Approximation of Fixed Points, (Lecture Notes in Mathematics, No. 1912), Springer, Berlin, 2007.
[37]   | I. Yamada: Viscosity approximation methods for nonexpansive mappings, J. Math. Anal. Appl., 298 (2004) 279-291.
[38]   | G. Marino and H.K. Xu: A general iterative method for nonexpansive mappings in Hilbert spaces, J. Math. Anal. Appl., 318 (2006) 43-52.
[39]   | E. Hofer: A partially implicit method for large stiff systems of ODEs with only few equations introducing small time-constants, SIAM J. Numer. Anal., 13 (1976) 645-663.
[40]   | P. Deuhard: Recent progress in extrapolation methods for ordinary differential equations, SIAM Rev., 27(4) (1985) 505-535.
[41]   | W, Auzinger and R. Frank: Asymptotic error expansions for stiff equations: an analysis for the implicit midpoint and trapezoidal rules in the strongly stiff case, Numer. Math., 56 (1989) 469-499.
[42]   | A. Bayreuth: The implicit midpoint rule applied to discontinuous differential equations, Computing, 49 (1992) 45-62.
[43]   | S. Somalia and S. Davulcua: Implicit midpoint rule and extrapolation to singularly perturbed boundary value problems, Int. J. Comput. Math., 75(1) (2000) 117-127.
[44]   | S. Somalia: Implicit midpoint rule to the nonlinear degenerate boundary value problems, Int. J. Comput. Math., 79(3) (2002) 327-332.
[45]   | M.A. Alghamdi, M.A., Alghamdi, N. Shahzad and H.K. Xu: The implicit midpoint rule for nonexpansive mappings. Fixed Point Theory Appl., 96 (2014), 9 pages.
[46]   | Shrijana Dhakal and Wutiphol Sintunavarat The viscosity method for the implicit double midpoint rule with numerical results and its applications, Sociedade Brasileira de Matematica Aplicada e Computacional 2019.
[47]   | F.L. Crane, H. Low, P. Navas, I.L. Sun, Control of cell growth by plasma membrane NADH oxidation, Pure and Applied Chemical Sciences, 1 (2013), 31-42.
[48]   | D.O. Hebb, The Organization of Behavior, Wiley, New York, 1949.