the aim of our research is to acquire ideal images of city and urban traffic for various purpose. To achieve the aim, we propose optimization models which consist of city, mobilities and inhabitants. there are two mod...
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ISBN:
(纸本)9781467327435;9781467327428
the aim of our research is to acquire ideal images of city and urban traffic for various purpose. To achieve the aim, we propose optimization models which consist of city, mobilities and inhabitants. there are two models we are proposed from point of view of accuracy and computation time. One is relatively accurate but takes a lot of time to compute. the other is less accurate, however, larger problems can be computed than the former model. the former model could not solve practical size due to computational time. through computational experiment using extreme evaluation values, validness of latter model is suggested.
In this paper we propose a new approach to solve combinatorialoptimization problems. Our approach is simple to implement but powerful in terms of performance and speed. We combine the strengths of a meta-heuristic ap...
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ISBN:
(纸本)076952236X
In this paper we propose a new approach to solve combinatorialoptimization problems. Our approach is simple to implement but powerful in terms of performance and speed. We combine the strengths of a meta-heuristic approach withthe integerprogramming method by partitioning the problem into two interrelated subproblems, where the higher level problem is solved by the metahueristic and the lower level problem is solved by integerprogramming. We discuss the selection of key variables to facilitate an effective partitioning, and test our approach on two real world cross-docking problems which is very popular in this part of the world. Our experimental results indicate that our new approach is very promising.
We investigate the optimization of inland transport routes of barge container ships withthe objective to maximize the profit of a shipping company. this problem consists of determining the upstream and downstream cal...
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ISBN:
(纸本)9780889868724
We investigate the optimization of inland transport routes of barge container ships withthe objective to maximize the profit of a shipping company. this problem consists of determining the upstream and downstream calling sequence and the number of loaded and empty containers transported between any two ports. We present combinatorial as well as Mixed integer Linear programming (MILP) formulation for this problem. We propose to combine these two approaches with an aim to generate efficient heuristic to solve considered problem. the proposed mixed-formulation Local Search (MIX-LS) represents good basis for implementation of LS-based meta-heuristic methods and we presented Multi-start Local Search (MLS) within this framework. To compare the proposed approach withthe state-of-the-art Mixed integerprogramming (MIP) based heuristics we run all methods within a predefined time limit. It appears that pure local search is comparable withthe MIPbased heuristic methods, while MLS outperforms all methods regarding both criteria: solution quality and running time.
A large-scale nonlinear MIP model of optimum locating of multistage stations in oil transportation is established. Because the model is very difficult to solve by traditional methods, a synthetic solution is presented...
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ISBN:
(纸本)7560323553
A large-scale nonlinear MIP model of optimum locating of multistage stations in oil transportation is established. Because the model is very difficult to solve by traditional methods, a synthetic solution is presented by a Hopfield neural network algorithm. In establishing the optimization model, the real continuous variables are changed into discrete 0-1 integer variables so that the nonlinear MIP model is transferred into a pure 0-1 nonlinear IP model and it is possible to solve the model with high speed because the whole solving process falls into a binary calculation environment. In the solution, a simulating machine based on the Hopfield neural network model is developed by C++ computer language, the structural parameters of the machine are deduced from the optimization model. A practical application shows that the simulating machine can find optimization results with high speed.
Based on our previously proposed Quantum-behaved Particle Swarm optimization (QPSO), this paper discusses the applicability of QPSO to integerprogramming. QPSO is a global convergent search method, while the original...
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ISBN:
(纸本)3540464816
Based on our previously proposed Quantum-behaved Particle Swarm optimization (QPSO), this paper discusses the applicability of QPSO to integerprogramming. QPSO is a global convergent search method, while the original Particle Swarm (PSO) cannot be guaranteed to find out the optima solution of the problem at hand. the application of QPSO to integerprogramming is the first attempt of the new algorithm to discrete optimization problem. After introduction of PSO and detailed description of QPSO, we propose a method of using QPSO to solve integerprogramming. Some benchmark problems are employed to test QPSO as well as PSO for performance comparison. the experiment results show the superiority of QPSO to PSO on the problems.
We develop integerprogramming (IP) solutions for some special college admission problems arising from the Hungarian higher education admission scheme. We focus on four special features, namely the solution concept of...
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We develop integerprogramming (IP) solutions for some special college admission problems arising from the Hungarian higher education admission scheme. We focus on four special features, namely the solution concept of stable score-limits, the presence of lower and common quotas, and paired applications. We note that each of the latter three special feature makes the college admissions problem NP-hard to solve. Currently, a heuristic based on the Gale-Shapley algorithm is being used in the Hungarian application. the IP methods that we propose are not only interesting theoretically, but may also serve as an alternative solution concept for this practical application, and other similar applications. We finish the paper by presenting a simulation using the 2008 data of the Hungarian higher education admission scheme.
Large collections of digital knowledge have become valuable assets for search and recommendation applications. the taxonomic type systems of such knowledge bases are often highly heterogeneous, as they reflect differe...
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ISBN:
(纸本)9781450334730
Large collections of digital knowledge have become valuable assets for search and recommendation applications. the taxonomic type systems of such knowledge bases are often highly heterogeneous, as they reflect different cultures, languages, and intentions of usage. We present a novel method to the problem of multi-cultural knowledge alignment, which maps each node of a source taxonomy onto a ranked list of most suitable nodes in the target taxonomy. We model this task as combinatorialoptimization problems, using integer linear programming and quadratic programming. the quality of the computed alignments is evaluated, using large heterogeneous taxonomies about book categories.
this paper introduces two fundamental families of 'quasipolyhedra' - polyhedra with a countably infinite number of facets - that arise in the context of integer quadratic programming. It is shown that any inte...
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ISBN:
(纸本)9783642130359
this paper introduces two fundamental families of 'quasipolyhedra' - polyhedra with a countably infinite number of facets - that arise in the context of integer quadratic programming. It is shown that any integer quadratic program can be reduced to the minimisation of a linear function over a quasi-polyhedron in the first family. Some fundamental properties of the quasi-polyhedra are derived, along with connections to some other well-studied convex sets. Several classes of facet-inducing inequalities are also derived. Finally, extensions to the mixed-integer case are briefly examined.
We consider the question of which nonconvex sets can be represented exactly as the feasible sets of mixed-integer convex optimization problems. We state the first complete characterization for the case when the number...
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ISBN:
(纸本)9783319592503;9783319592497
We consider the question of which nonconvex sets can be represented exactly as the feasible sets of mixed-integer convex optimization problems. We state the first complete characterization for the case when the number of possible integer assignments is finite. We develop a characterization for the more general case of unbounded integer variables together with a simple necessary condition for representability which we use to prove the first known negative results. Finally, we study representability of subsets of the natural numbers, developing insight towards a more complete understanding of what modeling power can be gained by using convex sets instead of polyhedral sets;the latter case has been completely characterized in the context of mixed-integer linear optimization.
the infinite models in integerprogramming can be described as the convex hull of some points or as the intersection of halfspaces derived from valid functions. In this paper we study the relationships between these t...
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ISBN:
(数字)9783319592503
ISBN:
(纸本)9783319592503;9783319592497
the infinite models in integerprogramming can be described as the convex hull of some points or as the intersection of halfspaces derived from valid functions. In this paper we study the relationships between these two descriptions. Our results have implications for finite dimensional corner polyhedra. One consequence is that nonnegative continuous functions suffice to describe finite dimensional corner polyhedra with rational data. We also discover new facts about corner polyhedra with non-rational data.
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