Given a schedule of flight legs to be flown by an airline, the fleet assignment problem is determine minimum cost flights aircraft types, called fleets, such that each scheduled assigned exactly one fleet, and resulting feasible fly given limited number in fleet. Then airline must sequence flights, or routes, individual are included route, all can maintained as necessary. This referred routing problem. In this paper, we present single model solution approach solve simultaneously problems....

Abstract Much has been written on shortest path problems with weight, or resource, constraints. However, relatively little of it provided systematic computational comparisons for a representative selection algorithms. Furthermore, there almost no work showing numerical performance scaling algorithms, although worst‐case complexity guarantees these are well known, nor the effectiveness simple preprocessing techniques fully demonstrated. Here, we provide comparison three and standard...

Consolidation carriers transport shipments that are small relative to trailer capacity. To be cost effective, the carrier must consolidate shipments, which requires coordinating their paths in both space and time; i.e., solve a service network design problem. Most models rely on discretization of time—i.e., instead determining exact time at dispatch should occur, model determines interval during occur. While use is widespread models, fundamental question related its has never been answered:...

We present a new criterion space search algorithm, the balanced box method, for finding all nondominated points of biobjective integer program. The method extends is easy to implement, and converges quickly complete set points. Because maintains, at any point in time, diverse points, it ideally suited fast approximation efficient frontier. In addition, we several enhancements well-known ε-constraint, augmented weighted Tchebycheff, perpendicular methods. An extensive computational study,...

This paper applies recently developed mixed-integer programming (MIP) tools to the problem of optimal siting and sizing distributed generators in a distribution network. We investigate merits three MIP approaches for finding good installation plans: full AC power flow approach, linear DC approximation, nonlinear approximation with quadratic loss terms, each augmented integer generator placement variables. A genetic algorithm-based approach serves as baseline comparison. simple knapsack...

We consider the inventory routing problem, in which a supplier has to replenish set of customers by means limited fleet capacitated vehicles over discrete time horizon. The goal is minimize total cost distribution that comprises at and cost. present matheuristic combines tabu search mathematical programming formulations. When compared with two exact methods on 640 small instances, finds 192 (48%) optima 402 instances known improves 125 upper bounds. Tested 240 large (with up 200 customers)...

We present the first criterion space search algorithm, triangle splitting method, for finding all nondominated points of a biobjective mixed integer program. The algorithm is relatively easy to implement and converges quickly complete set points. maintains, at any point in time, diverse points, thus ideally suited fast approximation frontier. An extensive computational study demonstrates efficacy method. Data, as supplemental material, are available http://dx.doi.org/10.1287/ijoc.2015.0646 .

We present a new solution approach for the time-dependent traveling salesman problem with time windows. This considers who departs from his home, has to visit number of cities within predetermined period time, and then, returns home. The allows travel times that can depend on departure. consider two objectives problem: (1) makespan objective seeks return home as early possible (2) duration minimize amount he is away based an integer programming formulation time-expanded network, because...

Abstract In this article the modulation of intensity matrices arising in cancer radiation therapy using multileaf collimators (MLC) is investigated. It shown that problem equivalent to decomposing a given integer matrix into positive linear combination (0, 1) matrices. These matrices, called shape , must have strict consecutive‐1‐property, together with another property derived from technological restrictions MLC equipment. Various decompositions can be evaluated by their beam‐on time (time...

The reconfiguration of distribution networks is an important combinatorial problem. This work addresses the particular case after outage caused by loss a single branch network. carried out over two domains simultaneously: re-switching strategies and transformer tap-changer adjustments. approach was tested using real large-scale network within concession area Energy Australia. model considers four operational elements: AC power flow model, network's radial topology when operating, voltage...

We present a new primal-dual algorithm for computing the value of Lagrangian dual stochastic mixed-integer program (SMIP) formed by relaxing its nonanticipativity constraints. This is widely used in decomposition methods solution SMIPs. The relies on well-known progressive hedging method, but unlike previous approaches SMIP, our can be shown to converge optimal value. key improvement an inner loop optimized linearization steps, similar those taken classical Frank--Wolfe method. Numerical...

With over 100 millions tons of coal exported annually, the terminals at Port Newcastle are among busiest in world. To accommodate anticipated rise export next decade, effective stockyard management will be essential. We have developed planning technology that can achieve substantially higher throughput levels. The intelligently combines greedy construction, enumeration, and integer programming. demonstrate efficacy on a variety instances derived from real-life data also show how used to...