Contrary to popular belief, geometric programming is not just a special technique for studying the very important class of posynomial (optimization) problems. It is really a very general mathematical theory that is es...
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Contrary to popular belief, geometric programming is not just a special technique for studying the very important class of posynomial (optimization) problems. It is really a very general mathematical theory that is especially useful for studying a large class of separable problems. Its practical efficacy is due mainly to the fact that many important (seemingly inseparable) problems can actually be formulated as separable geometric programming problems, by fully exploiting their linear algebraic structure. Some examples are: nonlinear network flow problems (both single-commodity and multicommodity), discrete optimal control problems with linear dynamics, optimal location problems of the generalized Fermat type, (lgeometric programming
Mathematical theorems
Optimal solutions
Mathematical duality
Mathematical vectors
Mathematical functions
Lagrangian function
Vector spaces
Objective functions
Symmetry
Uncertain geometric programming is a type of geometric programming involving uncertain variables. As described in the literature, the uncertain geometric programming model based on expected value cannot reflect the ri...
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Uncertain geometric programming is a type of geometric programming involving uncertain variables. As described in the literature, the uncertain geometric programming model based on expected value cannot reflect the risk preference of decision-makers. It motivates us to establish an uncertain geometric programming model based on value-at-risk to describe the risk level that managers can tolerate. Firstly, we propose the uncertain geometric programming model based on value-at-risk. Then, according to the operational law in uncertainty theory, this model is transformed into a crisp and equivalent form. Three numerical examples are used to verify the model's efficacy, and the paper emphasizes the influence of confidence level in the objective function and the constraints. In addition, the paper discusses the expected value model under an uncertain environment and presents the difference between expected value and value-at-risk. Finally, we apply the model to the problem of a two-bar truss, and the optimal solution can be obtained within the risk level that the structural designer can accept.
In this paper, an optimization model for minimizing an objective function with single-term exponents subject to fuzzy relational equations specified in max-product composition is presented. The solution set of such a ...
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In this paper, an optimization model for minimizing an objective function with single-term exponents subject to fuzzy relational equations specified in max-product composition is presented. The solution set of such a fuzzy relational equation is a non-convex set. First, we present some properties for the optimization problem under the assumptions of both negative and nonnegative exponents in the objective function. Second, an efficient procedure is developed to find an optimal solution without looking for all the potential minimal solutions and without using the value matrix. An example is provided to illustrate the procedure. (C) 2010 Elsevier Ltd. All rights reserved.
In this paper, we consider a relaying system which employs a single relay in a wireless network with distributed sources and destinations. Here, all source, destination, and relay nodes are equipped with multiple ante...
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In this paper, we consider a relaying system which employs a single relay in a wireless network with distributed sources and destinations. Here, all source, destination, and relay nodes are equipped with multiple antennas. For amplify-and-forward relay systems, we confirm the achievable sum rate through a joint multiple source precoders and a single relay filter design. To this end, we propose a new linear processing scheme in terms of maximizing the sum rate performance by applying a blockwise relaying method combined with geometric programming techniques. By allowing the global channel knowledge at the source nodes, we show that this joint design problem is formulated as a standard geometric program, which can guarantees a global optimal value under the modified sum rate criterion. Simulation results show that the proposed blockwise relaying scheme with the joint power allocation method provides substantial sum rate gain compared to the conventional schemes.
We study geometric programming with a single-term exponent subject to bipolar max-product fuzzy relation equation constraints in the area of economics and the covering problem. The structure of its feasible domain is ...
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We study geometric programming with a single-term exponent subject to bipolar max-product fuzzy relation equation constraints in the area of economics and the covering problem. The structure of its feasible domain is characterized and the lower and upper bound vectors on its solution set are determined. It is shown that each component of one of its optimal solutions is the corresponding component of either the lower bound or the upper bound vector. This interesting property helps us to create a value matrix and present some necessary and sufficient conditions for its consistency checking. Moreover, some sufficient conditions are proposed to detect one of its optimal solutions without solving the problem. A modified branch-and-bound method is extended to solve the problem, in a general case, with use of the value matrix. An efficient algorithm is then designed to solve the problem using the sufficient conditions and the modified branch-and-bound method. Its computational complexity is also analyzed. Finally, some examples are provided to illustrate its importance and the steps of the algorithm. (C) 2019 Elsevier B.V. All rights reserved.
geometric programming provides a powerful tool for solving a variety of engineering optimization problems. Many applications of geometric programming are engineering design problems in which some of the problem parame...
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geometric programming provides a powerful tool for solving a variety of engineering optimization problems. Many applications of geometric programming are engineering design problems in which some of the problem parameters are estimates of actual values. When the parameters in the problem are imprecise, the calculated objective value should be imprecise as well. This paper develops a procedure to derive the fuzzy objective value of the fuzzy posynomial geometric programming problem when the exponents of decision variables in the objective function, the cost and the constraint coefficients, and the right-hand sides are fuzzy numbers. The idea is based on Zadeh's extension principle to transform the fuzzy geometric programming problem into a pair of two-level of mathematical programs. Based on duality algorithm and a simple algorithm, the pair of two-level mathematical programs is transformed into a pair of conventional geometric programs. The upper bound and lower bound of the objective value are obtained by solving the pair of geometric programs. From different values of a, the membership function of the objective value is constructed. Two examples are used to illustrate that the whole idea proposed in this paper. (C) 2007 Elsevier Inc. All rights reserved.
geometric programming is a well-known optimization tool for dealing with a wide range of nonlinear optimization and engineering problems. In general, it is assumed that the parameters of a geometric programming proble...
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geometric programming is a well-known optimization tool for dealing with a wide range of nonlinear optimization and engineering problems. In general, it is assumed that the parameters of a geometric programming problem are deterministic and accurate. However, in the real-world geometric programming problem, the parameters are frequently inaccurate and ambiguous. To tackle the ambiguity, this paper investigates the geometric programming problem in an uncertain environment, with the coefficients as triangular and trapezoidal twofold uncertain variables. In this paper, we introduce uncertain measures in a generalized version and focus on more complicated twofold uncertainties to propose triangular and trapezoidal twofold uncertain variables within the context of uncertainty theory. We develop three reduction methods to convert triangular and trapezoidal twofold uncertain variables into singlefold uncertain variables using optimistic, pessimistic, and expected value criteria. Reduction methods are used to convert the geometric programming problem with twofold uncertainty into the geometric programming problem with singlefold uncertainty. Furthermore, the chance-constrained uncertain-based framework is used to solve the reduced singlefold uncertain geometric programming problem. Finally, a numerical example is provided to demonstrate the effectiveness of the procedures.
geometric programming problems in which several of the variables are restricted to assume either integer values or one of a set of standard sizes are known as Semi-Discrete geometric programming problems. In this pape...
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geometric programming problems in which several of the variables are restricted to assume either integer values or one of a set of standard sizes are known as Semi-Discrete geometric programming problems. In this paper several variations of Generalized Benders' Decomposition are described for these problems and some computational experience is presented.
Smart manufacturing systems should always aim to be fully sustainable while simultaneously being as reliable as possible which is difficult to reach. Furthermore, climate change especially by carbon emission in the in...
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Smart manufacturing systems should always aim to be fully sustainable while simultaneously being as reliable as possible which is difficult to reach. Furthermore, climate change especially by carbon emission in the industry is a significant topic and carbon emission should be controlled and reduced to save the environment. Contributing towards a greener environment in a positive manner is done by reducing the number of insufficient items that are produced in a smart production system which also can be reached with higher reliability in the system. Therefore, this study models a smart reliable production system with controlled carbon ejection. To solve the proposed smart production system in this study, a geometric programming approach with a degree of difficulty level two is used which results in optimum results that are quasi-closed. Furthermore, numerical experiments are conducted to validate the proposed model and prove that by using a higher degree geometric programming approach, an optimal solution is found. The numerical results do not only show optimal solutions but also that the smart production system with controlled carbon ejection is reliable.
We study one-dimensional doping profile design optimization problem of metal-oxide-semiconductor (MOS) devices using a geometric programming (GP) technique. To model the explored optimal doping profile into a GP probl...
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We study one-dimensional doping profile design optimization problem of metal-oxide-semiconductor (MOS) devices using a geometric programming (GP) technique. To model the explored optimal doping profile into a GP problem, the subthreshold swing is formulated as an objective function and the on- and off-state currents are considered as constraints for solving the corresponding optimal doping profile. The GP problem is a special type of convex optimization and is solved globally and efficiently using the existing numerical solvers in GGPLAB. The accuracy of optimized results is validated by comparing with numerical semiconductor device simulation. This approach provides a way to optimize doping problem which may benefit manufacturing of MOS devices. (C) 2012 Elsevier Ltd. All rights reserved.
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