This overview paper discusses the framework of sequential fractional programming for energy efficiency maximization in future 5G networks. One of the main features of future systems will be the presence of severe mult...
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This overview paper discusses the framework of sequential fractional programming for energy efficiency maximization in future 5G networks. One of the main features of future systems will be the presence of severe multi-user interference and the need of improved energy efficiency compared to present systems. However, present approaches to energy efficiency maximization, which are based on the theory of fractional programming, result in an exponential complexity in interference-limited networks. In this context, the work shows how to extend available fractional programming approaches to obtain radio resource allocations enjoying strong optimality properties, while at the same time requiring an affordable complexity to be computed. The resulting framework is termed sequential fractional programming, and several examples of its applications to leading 5G candidate technologies are discussed in detail. (C) 2016 Elsevier Inc. All rights reserved.
The aim of this paper is to obtain sufficient optimality conditions for a nonlinear multiple objective fractional programming problem involving semilocally type-I univex and related functions. Furthermore, a general d...
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The aim of this paper is to obtain sufficient optimality conditions for a nonlinear multiple objective fractional programming problem involving semilocally type-I univex and related functions. Furthermore, a general dual is formulated and duality results are proved under the assumptions of generalized semilocally type-I univex and related functions. Our results generalize several known results in the literature.
Climate change mitigation by reducing greenhouse gas emissions is one of the major challenges for existing electric power systems. This study presents a multi-stage joint-probabilistic left-hand-side chance-constraine...
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Climate change mitigation by reducing greenhouse gas emissions is one of the major challenges for existing electric power systems. This study presents a multi-stage joint-probabilistic left-hand-side chance-constrained fractional programming (MJCFP) approach to help tackle various uncertainties involved in typical electric power systems and thus facilitate risk-based management for climate change mitigation. The MJCFP approach is capable of solving ratio optimization problems associated with left-hand-side random information by integrating multi-stage programming method, joint-probabilistic chance-constrained programming, fractional programming into a general framework. It can balance dual-objectives of two aspects reflecting system optimal ratio and analyze many of possible scenarios due to various end-user demand situations during different periods. The MJCFP approach is implemented and applied to the provincial electric power system of Saskatchewan, Canada to demonstrate its effectiveness in dealing with the tradeoff between economic development and climate change mitigation. Potential solutions under various risk levels are obtained to help identify appropriate strategies to meet different power demands and emission targets to the maximum extent. The results indicate that the MJCFP approach is effective for regional electric power system planning in support of long-term climate change mitigation policies;it can also generate more alternatives through risk-based management, which allows in-depth analysis of the interrelationships among system efficiency, system profit and system-failure risk.
作者:
Wang, YadiLi, XiaopingWang, JunHenan Univ
Henan Key Lab Big Data Anal & Proc Kaifeng 475004 Peoples R China Henan Univ
Inst Data & Knowledge Engn Sch Comp & Informat Engn Kaifeng 475004 Peoples R China Southeast Univ
Sch Comp Sci & Engn Nanjing 211189 Peoples R China Southeast Univ
Minist Educ Key Lab Comp Network & Informat Integrat Nanjing 211189 Peoples R China City Univ Hong Kong
Dept Comp Sci Kowloon Hong Kong Peoples R China City Univ Hong Kong
Sch Data Sci Kowloon Hong Kong Peoples R China
Feature selection is an important issue in machine learning and data mining. Most existing feature selection methods are greedy in nature thus are prone to sub-optimality. Though some global feature selection methods ...
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Feature selection is an important issue in machine learning and data mining. Most existing feature selection methods are greedy in nature thus are prone to sub-optimality. Though some global feature selection methods based on unsupervised redundancy minimization can potentiate clustering performance improvements, their efficacy for classification may be limited. In this paper, a neurodynamics-based holistic feature selection approach is proposed via feature redundancy minimization and relevance maximization. An information-theoretic similarity coefficient matrix is defined based on multi-information and entropy to measure feature redundancy with respect to class labels. Supervised feature selection is formulated as a fractional programming problem based on the similarity coefficients. A neurodynamic approach based on two one-layer recurrent neural networks is developed for solving the formulated feature selection problem. Experimental results with eight benchmark datasets are discussed to demonstrate the global convergence of the neural networks and superiority of the proposed neurodynamic approach to several existing feature selection methods in terms of classification accuracy, precision, recall, and F-measure. (C) 2021 Elsevier Ltd. All rights reserved.
The posynomial fractional programming (PFP) problem arises from the summation minimization of several quotient terms, which are composed of posynomial terms appearing in the objective function subject to given posynom...
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The posynomial fractional programming (PFP) problem arises from the summation minimization of several quotient terms, which are composed of posynomial terms appearing in the objective function subject to given posynomial constraints. This paper proposes an approximate approach to solving a PFP problem. A linear programming relaxation is derived for the problem based on piecewise linearization techniques, which first convert a posynomial term into the sum of absolute terms;these absolute terms are then linearized by some linearization techniques. The proposed approach could reach a solution as close as possible to a global optimum. (C) 2002 Elsevier Science B.V. All rights reserved.
We present a new mixed-integer programming (MIP) approach to study certain retail category pricing problems that arise in practice. The motivation for this research arises from the need to design innovative analytic r...
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We present a new mixed-integer programming (MIP) approach to study certain retail category pricing problems that arise in practice. The motivation for this research arises from the need to design innovative analytic retail optimization techniques at Oracle Corporation to not only predict the empirical effect of price changes on the overall sales and revenue of a category, but also to prescribe optimal dynamic pricing recommendations across a category or demand group. A multinomial logit nonlinear optimization model is developed, which is recast as a discrete, nonlinear fractional program (DNFP). The DNFP model employs a bi-level, predictive modeling framework to manage the empirical effects of price elasticity and competition on sales and revenue, and to maximize the gross-margin of the demand group, while satisfying certain practical side-constraints. This model is then transformed by using the Reformulation-Linearization Technique in tandem with a sequential bound-tightening scheme to recover an MIP formulation having a relatively tight underlying linear programming relaxation, which can be effectively solved by any commercial optimization software package. We present sample computational results using randomly generated instances of DNFP having different constraint settings and price range restrictions that are representative of common business requirements, and analyze the empirical effects of certain key modeling parameters. Our results indicate that the proposed retail price optimization methodology can be effectively deployed within practical retail category management applications for solving DNFP instances that typically occur in practice.
Generalizations of the well-known simplex method for linear programming are available to solve the piecewise linear programming problem and the linear fractional programming problem. In this paper we consider a furthe...
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Generalizations of the well-known simplex method for linear programming are available to solve the piecewise linear programming problem and the linear fractional programming problem. In this paper we consider a further generalization of the simplex method to solve piecewise linear fractional programming problems unifying the simplex method for linear programs, piecewise linear programs, and the linear fractional programs. Computational results are presented to obtain further insights into the behavior of the algorithm on random test problems. (c) 2006 Elsevier B.V. All rights reserved.
Redundancy in constraints and variables axe usually studied in linear, integer and non-linear programming problems. However, main emphasis has so far been given only to linear programming problems. In this paper, an a...
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Redundancy in constraints and variables axe usually studied in linear, integer and non-linear programming problems. However, main emphasis has so far been given only to linear programming problems. In this paper, an algorithm that identifies redundant objective functions in multi-objective stochastic fractional programming problems is provided. A solution procedure is also illustrated. This reduces the number of objective functions in cases where redundant objective functions exist.
Due to the effects of channel aging and estimation errors, perfect instantaneous channel state information (CSI) is unavailable at a base station. Therefore, robust precoding under imperfect CSI is important for pract...
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Due to the effects of channel aging and estimation errors, perfect instantaneous channel state information (CSI) is unavailable at a base station. Therefore, robust precoding under imperfect CSI is important for practical communications. In this letter, we propose an efficient robust precoding design for massive multiple-input multiple-output systems. Based on the fractional programming technique, we transform the original non-convex optimization problem into a much more tractable equivalent problem, which can be iteratively solved by alternating optimization. Since all variables are updated via closed-form optimal solutions, the proposed algorithm is guaranteed to converge to a locally optimal point. Simulation results reveal that the proposed robust precoding algorithm has fast convergence and achieves significant performance improvement over the conventional ones.
Reconfigurable intelligent surface (RIS) is a promising solution to programmable wireless channels. However, most existing RIS phase optimization algorithms, relying on iterative processes, suffer from high latency an...
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Reconfigurable intelligent surface (RIS) is a promising solution to programmable wireless channels. However, most existing RIS phase optimization algorithms, relying on iterative processes, suffer from high latency and poor scalability. To address this issue, we propose a low-complexity scheme based on deep unfolding. Specifically, we consider a downlink MISO system aided by a RIS and aim to maximize users' weighted sumrate (WSR). We employ Lagrangian dual transformation to decouple the original non-convex problem into two sub-problems: transmit beamforming optimization and phase shift design. Then, we introduce a block coordinate descent (BCD) method, which still relies on iterative updates and includes complex operations such as matrix inversion, leading to high computational complexity and latency. To achieve fast solutions, we further propose to unfold the BCD method's iterative process into layers of an interpretable neural network (NN) with a few trainable parameters. The NN is trained offline and deployed online for realtime solutions. Finally, numerical results validate the performance of the proposed scheme in terms of comparable WSR and reduced computational complexity.
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