• 제목/요약/키워드: subgradient

검색결과 48건 처리시간 0.021초

WEAK AND STRONG CONVERGENCE OF SUBGRADIENT EXTRAGRADIENT METHODS FOR PSEUDOMONOTONE EQUILIBRIUM PROBLEMS

  • Hieu, Dang Van
    • 대한수학회논문집
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    • 제31권4호
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    • pp.879-893
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    • 2016
  • In this paper, we introduce three subgradient extragradient algorithms for solving pseudomonotone equilibrium problems. The paper originates from the subgradient extragradient algorithm for variational inequalities and the extragradient method for pseudomonotone equilibrium problems in which we have to solve two optimization programs onto feasible set. The main idea of the proposed algorithms is that at every iterative step, we have replaced the second optimization program by that one on a specific half-space which can be performed more easily. The weakly and strongly convergent theorems are established under widely used assumptions for bifunctions.

A Random Deflected Subgradient Algorithm for Energy-Efficient Real-time Multicast in Wireless Networks

  • Tan, Guoping;Liu, Jianjun;Li, Yueheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권10호
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    • pp.4864-4882
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    • 2016
  • In this work, we consider the optimization problem of minimizing energy consumption for real-time multicast over wireless multi-hop networks. Previously, a distributed primal-dual subgradient algorithm was used for finding a solution to the optimization problem. However, the traditional subgradient algorithms have drawbacks in terms of i) sensitivity to iteration parameters; ii) need for saving previous iteration results for computing the optimization results at the current iteration. To overcome these drawbacks, using a joint network coding and scheduling optimization framework, we propose a novel distributed primal-dual Random Deflected Subgradient (RDS) algorithm for solving the optimization problem. Furthermore, we derive the corresponding recursive formulas for the proposed RDS algorithm, which are useful for practical applications. In comparison with the traditional subgradient algorithms, the illustrated performance results show that the proposed RDS algorithm can achieve an improved optimal solution. Moreover, the proposed algorithm is stable and robust against the choice of parameter values used in the algorithm.

SUBGRADIENT ESTIMATES FOR A NONLINEAR SUBELLIPTIC EQUATION ON COMPLETE PSEUDOHERMITIAN MANIFOLD

  • Han, Yingbo;Jiang, Kaige;Liang, Mingheng
    • 대한수학회보
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    • 제55권1호
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    • pp.175-186
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    • 2018
  • Let (M, J, ${\theta}$) be a complete pseudohermintian (2n+1)-manifold. In this paper, we derive the subgradient estimate for positive solutions to a nonlinear subelliptic equation ${\Delta}_bu+au{\log}u+bu=0$ on M, where $a{\leq}0$, b are two real constants.

MODIFIED SUBGRADIENT EXTRAGRADIENT ALGORITHM FOR PSEUDOMONOTONE EQUILIBRIUM PROBLEMS

  • Dang, Van Hieu
    • 대한수학회보
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    • 제55권5호
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    • pp.1503-1521
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    • 2018
  • The paper introduces a modified subgradient extragradient method for solving equilibrium problems involving pseudomonotone and Lipschitz-type bifunctions in Hilbert spaces. Theorem of weak convergence is established under suitable conditions. Several experiments are implemented to illustrate the numerical behavior of the new algorithm and compare it with a well known extragradient method.

THE SUBGRADIENT EXTRAGRADIENT METHOD FOR SOLVING MONOTONE BILEVEL EQUILIBRIUM PROBLEMS USING BREGMAN DISTANCE

  • Roushanak Lotfikar;Gholamreza Zamani Eskandani;Jong Kyu Kim
    • Nonlinear Functional Analysis and Applications
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    • 제28권2호
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    • pp.337-363
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    • 2023
  • In this paper, we propose a new subgradient extragradient algorithm for finding a solution of monotone bilevel equilibrium problem in reflexive Banach spaces. The strong convergence of the algorithm is established under monotone assumptions of the cost bifunctions with Bregman Lipschitz-type continuous condition. Finally, a numerical experiments is reported to illustrate the efficiency of the proposed algorithm.

A MODIFIED KRASNOSELSKII-TYPE SUBGRADIENT EXTRAGRADIENT ALGORITHM WITH INERTIAL EFFECTS FOR SOLVING VARIATIONAL INEQUALITY PROBLEMS AND FIXED POINT PROBLEM

  • Araya Kheawborisut;Wongvisarut Khuangsatung
    • Nonlinear Functional Analysis and Applications
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    • 제29권2호
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    • pp.393-418
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    • 2024
  • In this paper, we propose a new inertial subgradient extragradient algorithm with a new linesearch technique that combines the inertial subgradient extragradient algorithm and the KrasnoselskiiMann algorithm. Under some suitable conditions, we prove a weak convergence theorem of the proposed algorithm for finding a common element of the common solution set of a finitely many variational inequality problem and the fixed point set of a nonexpansive mapping in real Hilbert spaces. Moreover, using our main result, we derive some others involving systems of variational inequalities. Finally, we give some numerical examples to support our main result.

다중사용자 OFDM 광대역 무선인터넷 시스템의 자원할당 방법 (Resouce Allocation for Multiuser OFDM Systems)

  • 정용주;백천현;김후곤
    • 한국경영과학회지
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    • 제32권3호
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    • pp.33-46
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    • 2007
  • This study deals with the adaptive multiuser OFDM (Orthogonal Frequency Division Multiplexing) system which adjusts the resource allocation according to the environmental changes in such as wireless and quality of service required by users. The resource allocation includes subcarrier assignment to users, modulation method and power used for subcarriers. We first develop a general optimization model which maximizes data throughput while satisfying data rates required by users and total power constraints. Based on the property that this problem has the 0 duality gap, we apply the subgradient dual optimization method which obtains the solution of the dual problem by iteration of simple calculations. Extensive experiments with realistic data have shown that the subgradient dual method is applicable to the real world system, and can be used as a dynamic resource allocation mechanism.

Weak and Strong Convergence of Hybrid Subgradient Method for Pseudomonotone Equilibrium Problems and Nonspreading-Type Mappings in Hilbert Spaces

  • Sriprad, Wanna;Srisawat, Somnuk
    • Kyungpook Mathematical Journal
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    • 제59권1호
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    • pp.83-99
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    • 2019
  • In this paper, we introduce a hybrid subgradient method for finding an element common to both the solution set of a class of pseudomonotone equilibrium problems, and the set of fixed points of a finite family of ${\kappa}$-strictly presudononspreading mappings in a real Hilbert space. We establish some weak and strong convergence theorems of the sequences generated by our iterative method under some suitable conditions. These convergence theorems are investigated without the Lipschitz condition for bifunctions. Our results complement many known recent results in the literature.

Halpern Subgradient Method for Pseudomonotone Equilibrium Problems in Hilbert Space

  • Thang, Tran Van;Khoa, Nguyen Minh
    • Kyungpook Mathematical Journal
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    • 제62권3호
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    • pp.533-555
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    • 2022
  • In this paper, we introduce a new algorithm for finding a solution of an equilibrium problem in a real Hilbert space. Our paper extends the single projection method to pseudomonotone variational inequalities, from a 2018 paper of Shehu et. al., to pseudomonotone equilibrium problems in a real Hilbert space. On the basis of the given algorithm for the equilibrium problem, we develop a new algorithm for finding a common solution of a equilibrium problem and fixed point problem. The strong convergence of the algorithm is established under mild assumptions. Several of fundamental experiments in finite (infinite) spaces are provided to illustrate the numerical behavior of the algorithm for the equilibrium problem and to compare it with other algorithms.