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 Subjects -> ENGINEERING (Total: 2118 journals)     - CHEMICAL ENGINEERING (179 journals)    - CIVIL ENGINEERING (159 journals)    - ELECTRICAL ENGINEERING (89 journals)    - ENGINEERING (1163 journals)    - ENGINEERING MECHANICS AND MATERIALS (341 journals)    - HYDRAULIC ENGINEERING (54 journals)    - INDUSTRIAL ENGINEERING (54 journals)    - MECHANICAL ENGINEERING (79 journals) ENGINEERING (1163 journals)            First | 2 3 4 5 6 7 8 9 | Last
 International Journal of Hypersonics       (Followers: 3) International Journal of Imaging Systems and Technology       (Followers: 2) International Journal of Impact Engineering       (Followers: 7) International Journal of Information Acquisition       (Followers: 1) International Journal of Innovation and Applied Studies       (Followers: 2) International Journal of Innovation Science       (Followers: 6) International Journal of Innovative Technology and Research International Journal of Integrated Engineering       (Followers: 1) International Journal of Intelligent Engineering Informatics International Journal of Intelligent Systems and Applications in Engineering International Journal of Lifecycle Performance Engineering       (Followers: 1) International Journal of Machine Tools and Manufacture       (Followers: 5) International Journal of Manufacturing Research       (Followers: 5) International Journal of Manufacturing Technology and Management       (Followers: 7) International Journal of Materials and Product Technology       (Followers: 4) International Journal of Mathematical Education in Science and Technology       (Followers: 7) International Journal of Mathematics in Operational Research       (Followers: 1) International Journal of Medical Engineering and Informatics       (Followers: 5) International Journal of Micro Air Vehicles       (Followers: 4) International Journal of Microwave and Wireless Technologies       (Followers: 1) International Journal of Microwave Science and Technology       (Followers: 2) International Journal of Mobile Network Design and Innovation       (Followers: 3) International Journal of Multiphase Flow       (Followers: 2) International Journal of Nanomanufacturing       (Followers: 1) International Journal of Nanoscience       (Followers: 1) International Journal of Nanotechnology       (Followers: 5) International Journal of Nanotechnology and Molecular Computation       (Followers: 3) International Journal of Navigation and Observation       (Followers: 8) International Journal of Network Management International Journal of Nonlinear Sciences and Numerical Simulation International Journal of Numerical Methods for Heat & Fluid Flow       (Followers: 7) International Journal of Optics       (Followers: 1) International Journal of Organisational Design and Engineering       (Followers: 10) International Journal of Pattern Recognition and Artificial Intelligence       (Followers: 6) International Journal of Pavement Engineering       (Followers: 2) International Journal of Physical Modelling in Geotechnics       (Followers: 3) International Journal of Plasticity       (Followers: 6) International Journal of Plastics Technology International Journal of Polymer Analysis and Characterization       (Followers: 5) International Journal of Polymer Science       (Followers: 16) International Journal of Precision Engineering and Manufacturing       (Followers: 5) International Journal of Precision Engineering and Manufacturing-Green Technology International Journal of Precision Technology International Journal of Pressure Vessels and Piping       (Followers: 3) International Journal of Production Economics       (Followers: 13) International Journal of Quality and Innovation       (Followers: 4) International Journal of Quality Assurance in Engineering and Technology Education       (Followers: 2) International Journal of Quality Engineering and Technology       (Followers: 2) International Journal of Quantum Information International Journal of Rapid Manufacturing       (Followers: 1) International Journal of Reliability, Quality and Safety Engineering       (Followers: 7) International Journal of Renewable Energy Technology       (Followers: 8) International Journal of Robust and Nonlinear Control       (Followers: 3) International Journal of Science Engineering and Advance Technology International Journal of Sediment Research       (Followers: 1) International Journal of Self-Propagating High-Temperature Synthesis       (Followers: 2) International Journal of Signal and Imaging Systems Engineering International Journal of Six Sigma and Competitive Advantage International Journal of Social Robotics       (Followers: 2) International Journal of Software Engineering and Knowledge Engineering       (Followers: 1) International Journal of Space Science and Engineering       (Followers: 2) International Journal of Speech Technology       (Followers: 4) International Journal of Spray and Combustion Dynamics       (Followers: 6) International Journal of Superconductivity International Journal of Surface Engineering and Interdisciplinary Materials Science       (Followers: 1) International Journal of Surface Science and Engineering       (Followers: 7) International Journal of Sustainable Engineering       (Followers: 7) International Journal of Sustainable Manufacturing       (Followers: 4) International Journal of Systems and Service-Oriented Engineering International Journal of Systems Assurance Engineering and Management International Journal of Systems, Control and Communications       (Followers: 2) International Journal of Technoethics       (Followers: 1) International Journal of Technology Management and Sustainable Development       (Followers: 1) International Journal of Technology Policy and Law       (Followers: 5) International Journal of Telemedicine and Applications       (Followers: 2) International Journal of Thermal Sciences       (Followers: 7) International Journal of Thermodynamics       (Followers: 2) International Journal of Turbo & Jet-Engines International Journal of Ultra Wideband Communications and Systems International Journal of Vehicle Autonomous Systems       (Followers: 1) International Journal of Vehicle Design       (Followers: 6) International Journal of Vehicle Information and Communication Systems       (Followers: 2) International Journal of Vehicle Noise and Vibration       (Followers: 3) International Journal of Vehicle Safety       (Followers: 5) International Journal of Vehicular Technology       (Followers: 2) International Journal of Virtual Technology and Multimedia       (Followers: 4) International Journal of Wavelets, Multiresolution and Information Processing International Journal on Artificial Intelligence Tools       (Followers: 4) International Nano Letters       (Followers: 9) International Review of Applied Sciences and Engineering International Scholarly Research Notices       (Followers: 221) Inverse Problems in Science and Engineering       (Followers: 2) Ionics IPTEK The Journal for Technology and Science IRBM News Ironmaking & Steelmaking       (Followers: 2) Irrigation and Drainage Systems ISA Transactions       (Followers: 1) IT Professional       (Followers: 3) Johnson Matthey Technology Review       (Followers: 2)
 Journal of Global Optimization   [SJR: 0.919]   [H-I: 51]   [6 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1573-2916 - ISSN (Online) 0925-5001    Published by Springer-Verlag  [2302 journals]
• An information guided framework for simulated annealing
• Abstract: Abstract This paper presents an information guided framework for stochastic optimization with simulated annealing. Information gathered during randomized exploration of the search domain is used as feedback with progressively increasing gain to drive the optimization procedure, potentially causing the annealing temperature to rise during the algorithm’s execution. The benefits of reheating during the annealing process are shown in terms of significant improvement in the algorithm’s performance, while also staying within bounds for its convergence. A guided-annealing temperature is defined that incorporates information into the annealing schedule. The resulting algorithm has two phases: phase I performs nearly unrestricted exploration as a reconnaissance of the optimization domain and phase II “re-heats” the annealing procedure and exploits information gathered during phase I. Phase I flows seamlessly into phase II via an information effectiveness parameter without need for user input. Conditions are derived to prevent excessive reheating that may jeopardize convergence characteristics. Several examples are presented to test the new algorithm.
PubDate: 2015-05-01

• The robust crew pairing problem: model and solution methodology
• Abstract: Abstract We present a new robust formulation for the crew pairing problem where flight and connection times are random and vary within an interval. The model protects against infeasibility with a specified level of uncertainty and minimizes crew cost in the worst case. The resulting robust terms in the objective function and in the resource constraints are nonlinear. We apply Lagrangian relaxation to separate the nonlinear terms in the subproblem leading to a new robust formulation of the shortest path problem with resource constraints. We show that the nonlinear subproblem can be solved as a series of linear auxiliary problems. The proposed solution methodology was successful to solve industry instances in very competitive times and led to more robust crew pairing solutions as shown by simulation experiments.
PubDate: 2015-05-01

• Reduction of state dependent sweeping process to unconstrained
differential inclusion
• Abstract: Abstract In this article we discuss the differential inclusion known as state dependent sweeping process for a class of prox-regular non-convex sets. We associate with any state dependent sweeping process with such sets an unconstraint differential inclusion whose any solution is a solution of the state sweeping process too. We prove a theorem on the existence of a global solution of nonconvex state dependent sweeping process with unbounded perturbations. The perturbations are not required to be convex valued.
PubDate: 2015-05-01

• Finding nadir points in multi-objective integer programs
• Abstract: Abstract We address the problem of finding the nadir point in a multi-objective integer programming problem. Finding the nadir point is not straightforward, especially when there are more than three objectives. The difficulty further increases for integer programming problems. We develop an exact algorithm to find the nadir point in multi-objective integer programs with integer-valued parameters. We also develop a variation that finds bounds for each component of the nadir point with a desired level of accuracy. We demonstrate on several instances of multi-objective assignment, knapsack, and shortest path problems that the algorithms work well.
PubDate: 2015-05-01

• Computing the nadir point for multiobjective discrete optimization
problems
• Abstract: Abstract We investigate the problem of finding the nadir point for multiobjective discrete optimization problems (MODO). The nadir point is constructed from the worst objective values over the efficient set of a multiobjective optimization problem. We present a new algorithm to compute nadir values for MODO with $$p$$ objective functions. The proposed algorithm is based on an exhaustive search of the $$(p-2)$$ -dimensional space for each component of the nadir point. We compare our algorithm with two earlier studies from the literature. We give numerical results for all algorithms on multiobjective knapsack, assignment and integer linear programming problems. Our algorithm is able to obtain the nadir point for relatively large problem instances with up to five-objectives.
PubDate: 2015-05-01

• A preference-based evolutionary algorithm for multiobjective optimization:
the weighting achievement scalarizing function genetic algorithm
• Abstract: Abstract When solving multiobjective optimization problems, preference-based evolutionary multiobjective optimization (EMO) algorithms introduce preference information into an evolutionary algorithm in order to focus the search for objective vectors towards the region of interest of the Pareto optimal front. In this paper, we suggest a preference-based EMO algorithm called weighting achievement scalarizing function genetic algorithm (WASF-GA), which considers the preferences of the decision maker (DM) expressed by means of a reference point. The main purpose of WASF-GA is to approximate the region of interest of the Pareto optimal front determined by the reference point, which contains the Pareto optimal objective vectors that obey the preferences expressed by the DM in the best possible way. The proposed approach is based on the use of an achievement scalarizing function (ASF) and on the classification of the individuals into several fronts. At each generation of WASF-GA, this classification is done according to the values that each solution takes on the ASF for the reference point and using different weight vectors. These vectors of weights are selected so that the vectors formed by their inverse components constitute a well-distributed representation of the weight vectors space. The efficiency and usefulness of WASF-GA is shown in several test problems in comparison to other preference-based EMO algorithms. Regarding a metric based on the hypervolume, we can say that WASF-GA has outperformed the other algorithms considered in most of the problems.
PubDate: 2015-05-01

• Existence and characterization theorems in nonconvex vector optimization
• Abstract: Abstract This paper presents existence conditions and characterization theorems for minimal points of nonconvex vector optimization problems in reflexive Banach spaces. Characterization theorems use special class of monotonically increasing sublinear scalarizing functions which are defined by means of elements of augmented dual cones. It is shown that the Hartley cone-compactness is necessary and sufficient to guarantee the existence of a properly minimal point of the problem. The necessity is proven in the case of finite dimensional space.
PubDate: 2015-05-01

• GLODS: Global and Local Optimization using Direct Search
• Abstract: Abstract Locating and identifying points as global minimizers is, in general, a hard and time-consuming task. Difficulties increase in the impossibility of using the derivatives of the functions defining the problem. In this work, we propose a new class of methods suited for global derivative-free constrained optimization. Using direct search of directional type, the algorithm alternates between a search step, where potentially good regions are located, and a poll step where the previously located promising regions are explored. This exploitation is made through the launching of several instances of directional direct searches, one in each of the regions of interest. Differently from a simple multistart strategy, direct searches will merge when sufficiently close. The goal is to end with as many direct searches as the number of local minimizers, which would easily allow locating the global extreme value. We describe the algorithmic structure considered, present the corresponding convergence analysis and report numerical results, showing that the proposed method is competitive with currently commonly used global derivative-free optimization solvers.
PubDate: 2015-05-01

• D-gap functions and descent techniques for solving equilibrium problems
• Abstract: Abstract A new algorithm for solving equilibrium problems with differentiable bifunctions is provided. The algorithm is based on descent directions of a suitable family of D-gap functions. Its convergence is proved under assumptions which do not guarantee the equivalence between the stationary points of the D-gap functions and the solutions of the equilibrium problem. Moreover, the algorithm does not require to set parameters according to thresholds which depend on regularity properties of the equilibrium bifunction. The results of preliminary numerical tests on Nash equilibrium problems with quadratic payoffs are reported. Finally, some numerical comparisons with other D-gap algorithms are drawn relying on some further tests on linear equilibrium problems.
PubDate: 2015-05-01

• Smaller SDP for SOS decomposition
• Abstract: Abstract A popular numerical method to compute sum of squares (SOS of polynomials) decompositions for polynomials is to transform the problem into semi-definite programming (SDP) problems and then solve them by SDP solvers. In this paper, we focus on reducing the sizes of inputs to SDP solvers to improve the efficiency and reliability of those SDP based methods. Two types of polynomials, convex cover polynomials and split polynomials, are defined. A convex cover polynomial or a split polynomial can be decomposed into several smaller sub-polynomials such that the original polynomial is SOS if and only if the sub-polynomials are all SOS. Thus the original SOS problem can be decomposed equivalently into smaller sub-problems. It is proved that convex cover polynomials are split polynomials and it is quite possible that sparse polynomials with many variables are split polynomials, which can be efficiently detected in practice. Some necessary conditions for polynomials to be SOS are also given, which can help refute quickly those polynomials which have no SOS representations so that SDP solvers are not called in this case. All the new results lead to a new SDP based method to compute SOS decompositions, which improves this kind of methods by passing smaller inputs to SDP solvers in some cases. Experiments show that the number of monomials obtained by our program is often smaller than that by other SDP based software, especially for polynomials with many variables and high degrees. Numerical results on various tests are reported to show the performance of our program.
PubDate: 2015-04-09

• Two-stage, single-lot, lot streaming problem for a $$1+2$$ 1 + 2 hybrid
flow shop
• Abstract: Abstract In this paper, we address a single-lot, lot streaming problem for a two-stage hybrid flow shop, which consists of one machine at Stage 1 and two parallel (identical) machines at Stage 2. The objective is to minimize makespan. The lot is to be split into sublots each of which is processed first on the machine at Stage 1, and then, on one of the machines at Stage 2. A sublot-attached removal time is incurred after processing each sublot at Stage 1. First, we assume the number of sublots for the lot to be known a priori and develop closed-form expressions to obtain optimal, continuous sublot sizes for this case. Then, we consider determination of an optimal number of sublots in addition to their sizes. We develop an upper bound on the number of sublots, $$N_{\text {pos}}$$ , and use an algorithm of $$O(N_{\text {pos}})$$ complexity in conjunction with the closed-form expressions for sublot sizes to obtain an optimal solution. We also address the problem of determining number of sublots and integer sublot sizes, and propose a heuristic method for its solution that relies on some key results from the continuous case of the problem. The results of our numerical experimentation reveal the efficacy of the proposed method to obtain near-optimal integer sublot sizes and makespan values that are within 2.35 % of the true optimum for the testbed of data used, each obtained within a few seconds of CPU time.
PubDate: 2015-04-08

• Optimal learning with a local parametric belief model
• Abstract: Abstract We are interested in maximizing smooth functions where observations are noisy and expensive to compute, as might arise in computer simulations or laboratory experimentations. We derive a knowledge gradient policy, which chooses measurements which maximize the expected value of information, while using a locally parametric belief model that uses linear approximations with radial basis functions. The method uses a compact representation of the function which avoids storing the entire history, as is typically required by nonparametric methods. Our technique uses the expected value of a measurement in terms of its ability to improve our estimate of the optimum, capturing correlations in our beliefs about neighboring regions of the function, without posing any assumptions on the global shape of the underlying function a priori. Experimental work suggests that the method adapts to a range of arbitrary, continuous functions, and appears to reliably find the optimal solution. Moreover, the policy is shown to be asymptotically optimal.
PubDate: 2015-04-03

• Duality and robust duality for special nonconvex homogeneous quadratic
programming under certainty and uncertainty environment
• Abstract: Abstract In this paper, we discuss a kind of special nonconvex homogenous quadratic programming (HQP) and the methods to solve the HQP in an environment with certainty or uncertainty. In an environment with certainty, we first establish a strong duality between the HQP and its Lagrange dual problem, with the help of the fact that the Lagrange dual problem is equivalent to a convex semidefinite programming (SDP). Then we obtain a global solution to the HQP by solving the convex SDP. Furthermore, in an environment with uncertainty, we formulate the robust counterpart of the HQP to cope with uncertainty. We also establish the robust strong duality between the robust counterpart and its optimistic counterpart under a mild assumption. Since the counterpart is equivalent to a convex SDP under the same assumption, we can obtain a global solution to the robust counterpart by solving the convex SDP under the same assumption.
PubDate: 2015-04-03

• Surrogate-RLT cuts for zero–one integer programs
• Abstract: Abstract In this paper, we consider the class of 0–1 integer problems and develop an effective cutting plane algorithm that gives valid inequalities called surrogate-RLT cuts (SR cuts). Here we implement the surrogate constraint analysis along with the reformulation–linearization technique (RLT) to generate strong valid inequalities. In this approach, we construct a tighter linear relaxation by augmenting SR cuts to the problem. The level- $$d$$ SR closure of a 0–1 integer program is the polyhedron obtained by intersecting all the SR cuts obtained from RLT polyhedron formed over each set of $$d$$ variables with its initial formulation. We present an algorithm for approximately optimizing over the SR closure. Finally, we present the computational result of SR cuts for solving 0–1 integer programming problems of well-known benchmark instances from MIPLIB 3.0.
PubDate: 2015-04-03

• Necessary optimality conditions for optimistic bilevel programming
problems using set-valued programming
• Abstract: Abstract In this paper we adapt the main results from Amahroq and Gadhi (J Glob Optim 21:435–443, 2001) for a general set-valued optimization problem to an optimistic bilevel programming problem as an optimization problem with implicitly given set-valued constraint. Since this constraint is assumed to be upper but not lower semicontinuous in the sense of Berge, we need to deal with a lower semicontinuous distance function to this mapping. In order to approximate the gradient of the distance function, we introduce a new concept for a directional convexificator. Some calculus rules for this new tool are adapted and several properties are characterized. The main result presents optimality conditions for an optimistic bilevel programming problem using a convexificator constructed with the aid of the directional convexificator.
PubDate: 2015-04-01

• Some equivalence results for well-posedness of hemivariational
inequalities
• Abstract: Abstract In the present paper, we are devoted to exploring conditions of well-posedness for hemivariational inequalities in reflexive Banach spaces. By using some equivalent formulations of the hemivariational inequality considered under different monotonicity assumptions, we establish two kinds of conditions under which the strong well-posedness and the weak well-posedness for the hemivariational inequality considered are equivalent to the existence and uniqueness of its solution, respectively.
PubDate: 2015-04-01

• On set-valued optimization problems with variable ordering structure
• Abstract: Abstract In this paper we introduce and investigate an optimality concept for set-valued optimization problems with variable ordering structure. In our approach, the ordering structure is governed by a set-valued map acting between the same spaces as the objective multifunction. Necessary optimality conditions for the proposed problem are derived in terms of Bouligand and Mordukhovich generalized differentiation objects.
PubDate: 2015-04-01

• Efficient upper and lower bounds for global mixed-integer optimal control
• Abstract: Abstract We present a control problem for an electrical vehicle. Its motor can be operated in two discrete modes, leading either to acceleration and energy consumption, or to a recharging of the battery. Mathematically, this leads to a mixed-integer optimal control problem (MIOCP) with a discrete feasible set for the controls taking into account the electrical and mechanical dynamic equations. The combination of nonlinear dynamics and discrete decisions poses a challenge to established optimization and control methods, especially if global optimality is an issue. Probably for the first time, we present a complete analysis of the optimal solution of such a MIOCP: solution of the integer-relaxed problem both with a direct and an indirect approach, determination of integer controls by means of the sum up rounding strategy, and calculation of global lower bounds by means of the method of moments. As we decrease the control discretization grid and increase the relaxation order, the obtained series of upper and lower bounds converge for the electrical car problem, proving the asymptotic global optimality of the calculated chattering behavior. We stress that these bounds hold for the optimal control problem in function space, and not on an a priori given (typically coarse) control discretization grid, as in other approaches from the literature. This approach is generic and is an alternative to global optimal control based on probabilistic or branch-and-bound based techniques. The main advantage is a drastic reduction of computational time. The disadvantage is that only local solutions and certified lower bounds are provided with no possibility to reduce these gaps. For the instances of the electrical car problem, though, these gaps are very small. The main contribution of the paper is a survey and new combination of state-of-the-art methods for global mixed-integer optimal control and the in-depth analysis of an important, prototypical control problem. Despite the comparatively low dimension of the problem, the optimal solution structure of the relaxed problem exhibits a series of bang-bang, path-constrained, and sensitivity-seeking arcs.
PubDate: 2015-04-01

• ( $$\epsilon$$ ϵ -)Efficiency in difference vector optimization
• Abstract: Abstract The paper deals with the problem of characterizing Pareto optima (efficient solutions) for the difference of two mappings vector-valued in a finite or infinite-dimensional preordered space. Closely related to the well-known optimality criterion of scalar DC optimization, a mixed vectorial condition is obtained in terms of both strong (Fenchel) and weak (Pareto) $$\epsilon$$ -subdifferentials that completely characterizes the exact or approximate weak efficiency. This condition also allows to deal with some special restricted mappings. Moreover, the condition established in the literature in terms of strong $$\epsilon$$ -subdifferentials for characterizing the strongly efficient solutions (usual optima), is shown here to remain valid without assuming that the objective space is order-complete.
PubDate: 2015-04-01

• On an extension of Pólya’s Positivstellensatz
• Abstract: Abstract In this paper we provide a generalization of a Positivstellensatz by Pólya [Pólya in Naturforsch Ges Zürich 73:141–145 1928]. We show that if a homogeneous polynomial is positive over the intersection of the non-negative orthant and a given basic semialgebraic cone (excluding the origin), then there exists a “Pólya type” certificate for non-negativity. The proof of this result uses the original Positivstellensatz by Pólya, and a Positivstellensatz by Putinar and Vasilescu [Putinar and Vasilescu C R Acad Sci Ser I Math 328(7) 1999].
PubDate: 2015-04-01

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