


Vol 77, No 11 (2016)
- Year: 2016
- Articles: 15
- URL: https://ogarev-online.ru/0005-1179/issue/view/8996
Topical Issue
A combined work optimization technology under resource constraints with an application to road repair
Abstract
We propose an approach for solving the task prioritization problem in road surface repair under bounded resources; the idea is to use a combination of defect recognition and classification methods based on statistical analysis and machine learning (random forests) with original methods for solving infinite-dimensional optimization problems (optical-geometric analogy). We show the results of a computational experiment that indicate high performance of the developed algorithms, and the resulting solutions were evaluated highly by experts in road facilities management. Our results may encourage more efficient use of resources to improve the quality of motorways.



Multi-index transportation problems with 1-nested structure
Abstract
Consideration was given to the solution of the multi-index transportation problems of linear and integer-linear programming. It was proposed to use the approach based on studying the reducibility of the multi-index transportation problems to the problem of the minimal cost in the treelike network. It was proved that within the framework of the reduction scheme the condition for 1-nesting of the multi-index problems is necessary and sufficient for reducibility to the problem of the minimal-cost flow problem on a treelike network. An algorithm was proposed to solve the 1-nested multi-index problems requiring as many computer operations as the square of variables in the original problem.



Estimating collision probabilities for trains on railroad stations based on a Poisson model
Abstract
We consider the problem of estimating the probability of collision between shunting trains and passenger trains on a railroad station. We assume that the flow of shunting trains is Poisson for every turnout switch on which side collisions are possible. The data for computations include the station’s topology, timetable of passenger trains, and possible routes of their passing through the station together with the intensities of shunting trains moving through nonisolated turnout switches where collisions are possible, and also mean values of train lengths and their velocities. The proposed mathematical model of train motion can be regarded as a first approximation in modeling the collision process for trains on a railroad station. We also consider a real life example.



Modelling railway freight traffic using the methods of graph theory and combinatorial optimization
Abstract
The optimization problem of planning the railway freight traffic was presented, and approaches to reduction of problem dimension by constructing a hierarchy of the problems of train traffic planning were described. The notion of conflict graph on a set of energy-efficient standard threads was introduced. A “traveling wave” algorithm to construct the conflict-free sets of standard threads of the train schedule on the basis of the conflict graph was proposed. The problem of optimal assignments and transportations of locomotives in terms of the minimized number of utilized locomotives was formulated, an algorithm to solve to it was given, and its complexity was estimated.



Stochastic optimization model of locomotive assignment to freight trains
Abstract
Consideration was given to the optimization model of assigning the locomotives to the freight trains. The model was formulated in terms of a dynamic problem of stochastic programming with probabilistic constraints. The state variables characterize positions of the locomotives and trains at each time instant. The variables defining the motion of locomotives and their assignment to trains at each time instant play the role of controls. The expectation of the total freight traffic is the criterial function of the problem. A two-stage hybrid algorithm to solve the problem was developed. It combines the coordinatewise search and a genetic algorithm. Results of the numerical experiment were given.



Routing under constraints: Problem of visit to megalopolises
Abstract
Consideration was given to the problems of routing transfers under conditions of precedence and dynamic constraints including the dependence of the list of jobs both already completed by the instant of transfer or, on the contrary, not yet completed. The transfer costs also can be dependent on the list of jobs. The megalopolises (nonempty finite sets) are the objects of visits, which corresponds to the possible multiple-choice of transfers. The widely understood dynamic programming in a realization not requiring (under the precedence conditions) construction of the entire array of the Bellman function values is used as the basic method of study. The procedure of constructing a “complete” solution including determination of the optimal solution route and track (trajectory) and the procedure determining the problem value (global extremum) can be used separately to test the heuristic algorithms. An efficient heuristic algorithm was constructed to solve the routing problems of great dimension complicated by the constraints typical of the sheet cutting on the machines with computerized numerical control. For moderate problems, the results obtained were compared with the optimal result provided by the dynamic programming.



Methods for choosing loaded train and car routes along a railroad network
Abstract
We consider the problems of designing the routes for freight cars from departure stations to destination stations and problems and planning model for the works and for finding the necessary number of trains to deliver a given number of freight cars from departure stations to destination stations.



A branch and cut heuristic for a runway scheduling problem
Abstract
The paper is focused on one of the major air traffic management problem that consists in sequencing and scheduling airplanes landing and taking off on a runway. This difficult practical task is still carried out by flight controllers manually with little help from decision support systems. In this paper we propose an approach based on a time indexed integer programming formulation. The formulation is solved with a branch and cut method combined with some heuristic rules for dimension reduction. The effectiveness of the proposed approach is illustrated by computational experiments on real-life problem instances for the Milano Linate airport.



Models and optimization problems for single-processor servicing of packets of objects
Abstract
We consider a servicing model for a stationary processor that services a finite collection of objects arriving in packets. A packet is considered to be serviced if all objects in this packet have finished servicing. For each packet, we know an individual penalty function which is monotone increasing from zero with the time a packet spends in the servicing system. We pose and study optimization problems with one and two criteria for evaluating the quality of servicing strategies. With the scheme shown in the paper, we construct a general solving algorithm based on the principle of dynamic programming and show examples of its implementation.



On one approach to constructing timetables of freight trains in a railroad network
Abstract
We consider scheduling problems for routing freight trains through a railroad network. To solve these problems, we propose models and methods that use ideas and principles previously applied to construct part processing job schedules in industrial shops. The proposed approaches have been implemented in software, and our computational experiments have shown their efficiency.



Stochastic Systems, Queueing Systems
Gradient-free proximal methods with inexact oracle for convex stochastic nonsmooth optimization problems on the simplex
Abstract
In this paper we propose a modification of the mirror descent method for non-smooth stochastic convex optimization problems on the unit simplex. The optimization problems considered differ from the classical ones by availability of function values realizations. Our purpose is to derive the convergence rate of the method proposed and to determine the level of noise that does not significantly affect the convergence rate.



Automation in Industry
Basics of MES construction concept for production industries
Abstract
Methods of MES construction concept for industrial production of processing type are considered: formation of its content, requirements to problems solved within it, strategy of creation planning, and MES components implementation.



Mathematical Game Theory and Applications
Mean field games based on stable-like processes
Abstract
We investigate the mean field games of N agents based on the nonlinear stable-like processes. The main result of the paper is that any solution of the limiting mean field consistency equation generates a 1/N-Nash equilibrium for the approximating game of N agents.



Equivalence and strategy-proofness of non-anonymous priority allotment mechanisms
Abstract
This paper gives an analytical characterization for the strategy-proof sequential allotment mechanisms of a limited resource that are equivalent to the straight and reverse priority mechanisms. The previously known equivalence of the anonymous priority mechanisms is extended to the non-anonymous case by establishing the following fact: for an arbitrary straight priority mechanism, there exists an equivalent reverse priority mechanism, but the converse fails. And finally, we provide a characterization for the class of reverse priority mechanisms having an equivalent straight priority mechanism.



A-equilibrium and fuzzy A-core in pure exchange model with externalities
Abstract
The paper suggests the concept of A-equilibrium that is a concretization of the “altruistic” Berge equilibrium adapted to the pure exchange models with externalities. In contrast to the classical markets, these models consider the external influence on the preferences of economic agents. In terms of an appropriate fuzzy domination, a cooperative characterization of the A-equilibrium allocations is given, and an analog of the classic core equivalence theorem is established.


