Nopparat Wairojjana

Nopparat Wairojjana


Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 August 2020 in Axioms
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Journal Article
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NWNopparat Wairojjana
Nopparat Wairojjana
Habib ur RehmanHabib ur Rehman
Habib ur Rehman
Manuel De La SenManuel De La Sen
Manuel De La Sen
Nuttapol PakkaranangNuttapol Pakkaranang
Nuttapol Pakkaranang
A plethora of applications from mathematical programming, such as minimax, and mathematical programming, penalization, fixed point to mention a few can be framed as equilibrium problems. Most of the techniques for solving such problems involve iterative methods that is why, in this paper, we introduced a new extragradient-like method to solve equilibrium problems in real Hilbert spaces with a Lipschitz-type condition on a bifunction. The advantage of a method is a variable stepsize formula that is updated on each iteration based on the previous iterations. The method also operates without the previous information of the Lipschitz-type constants. The weak convergence of the method is established by taking mild conditions on a bifunction. For application, fixed-point theorems that involve strict pseudocontraction and results for pseudomonotone variational inequalities are studied. We have reported various numerical results to show the numerical behaviour of the proposed method and correlate it with existing ones.

5 June 2020 in Journal of Mathematics and Computer Science
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Journal Article
Closed access
Habib ur RehmanHabib ur Rehman
Habib ur Rehman
Nuttapol PakkaranangNuttapol Pakkaranang
Nuttapol Pakkaranang
AHAzhar Hussain
Azhar Hussain
NWNopparat Wairojjana
Nopparat Wairojjana
In this paper, we propose a modified extragradient method for solving a strongly pseudomonotone equilibrium problem in a real Hilbert space. A strong convergence theorem relative to our proposed method is proved and the proposed method has worked without having the information of a strongly pseudomonotone constant and the Lipschitz-type constants of a bifunction. We have carried out our numerical explanations to justify our well-established convergence results, and we can see that our proposed method has a substantial improvement over the time of execution and number iterations.

15 October 2020 in Axioms
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Journal Article
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NWNopparat Wairojjana
Nopparat Wairojjana
Mudasir YounisMudasir Younis
Mudasir Younis
Habib ur RehmanHabib ur Rehman
Habib ur Rehman
Nuttapol PakkaranangNuttapol Pakkaranang
Nuttapol Pakkaranang
Nattawut PholasaNattawut Pholasa
Nattawut Pholasa
Variational inequality theory is an effective tool for engineering, economics, transport and mathematical optimization. Some of the approaches used to resolve variational inequalities usually involve iterative techniques. In this article, we introduce a new modified viscosity-type extragradient method to solve monotone variational inequalities problems in real Hilbert space. The result of the strong convergence of the method is well established without the information of the operator’s Lipschitz constant. There are proper mathematical studies relating our newly designed method to the currently state of the art on several practical test problems.

1 January 2021 in Demonstratio Mathematica
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Journal Article
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NWNopparat Wairojjana
Nopparat Wairojjana
Nuttapol PakkaranangNuttapol Pakkaranang
Nuttapol Pakkaranang
Nattawut PholasaNattawut Pholasa
Nattawut Pholasa
In this paper, we introduce a new algorithm for solving pseudomonotone variational inequalities with a Lipschitz-type condition in a real Hilbert space. The algorithm is constructed around two algorithms: the subgradient extragradient algorithm and the inertial algorithm. The proposed algorithm uses a new step size rule based on local operator information rather than its Lipschitz constant or any other line search scheme and functions without any knowledge of the Lipschitz constant of an operator. The strong convergence of the algorithm is provided. To determine the computational performance of our algorithm, some numerical results are presented.

3 September 2019 in Optimization
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Journal Article
Closed access
NWNopparat Wairojjana
Nopparat Wairojjana
Nuttapol PakkaranangNuttapol Pakkaranang
Nuttapol Pakkaranang
IUIzhar Uddin
Izhar Uddin
Poom KumamPoom Kumam
Poom Kumam
Aliyu Muhammed AwwalAliyu Muhammed Awwal
Aliyu Muhammed Awwal
In this paper, we are interested in solving minimization problem and common fixed point problem of finite family consisting asymptotically nonexpansive mappings in Hadamard spaces. For finding common solutions of their problems, we introduce a new modified proximal point algorithm involving convex combination technique. Under suitable conditions, Δ-convergence and strong convergence theorems are proved. Furthermore, we provide some numerical examples which show the efficiency and implementation of the proposed algorithm as well as show computational overview by comparing it with previously known algorithms.

17 August 2020 in Axioms
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Journal Article
Open access
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NWNopparat Wairojjana
Nopparat Wairojjana
Habib ur RehmanHabib ur Rehman
Habib ur Rehman
Ioannis K. ArgyrosIoannis K. Argyros
Ioannis K. Argyros
Nuttapol PakkaranangNuttapol Pakkaranang
Nuttapol Pakkaranang
Several methods have been put forward to solve equilibrium problems, in which the two-step extragradient method is very useful and significant. In this article, we propose a new extragradient-like method to evaluate the numerical solution of the pseudomonotone equilibrium in real Hilbert space. This method uses a non-monotonically stepsize technique based on local bifunction values and Lipschitz-type constants. Furthermore, we establish the weak convergence theorem for the suggested method and provide the applications of our results. Finally, several experimental results are reported to see the performance of the proposed method.