35 research outputs found
Solving variational inequalities defined on a domain with infinitely many linear constraints
We study a variational inequality problem whose domain is defined by infinitely many linear inequalities. A discretization method and an analytic center based inexact cutting plane method are proposed. Under proper assumptions, the convergence results for both methods are given. We also provide numerical examples to illustrate the proposed method
Solving Variational Inequalities Defined on A Domain with Infinitely Many Linear Constraints
We study a variational inequality problem whose domain
is defined by infinitely many linear inequalities. A
discretization method and an analytic center based
inexact cutting plane method are proposed. Under proper
assumptions, the convergence results for both methods are
given. We also provide numerical examples for the
proposed methods
Efficient Circulation of Railway Rolling Stock
Railway rolling stock (locomotives, carriages, and train units) is oneof the most significant cost sources for operatorsof passenger trains,both public and private. Rolling stock costsare due to materialacquisition, power supply, and material maintenance. The efficientcirculation of rolling stock material is therefore one of theobjectives pursued. In this paper we focus on the circulation of trainunits on a single line. In order to utilize the train units on thisline in an efficient way, they are added to or removed from the trainsin certain stations, according to the passengers' seat demand. Sinceadding and removing train units has to respect specific rules, it isimportant to know the exact order of the train units in the trains.This aspect strongly increases the complexity of the rolling stockcirculation problem. In this paper we present aninteger programmingapproach to solve this problem. We also apply this approach to a reallife case study based on the 2001-2002 timetable of NS Reizigers, themajor Dutch operator of passenger trains.logistics;operations research;public transportation;railways;rolling stock circulation
Efficient Circulation of Railway Rolling Stock
Railway rolling stock (locomotives, carriages, and train units) is one
of the most significant cost sources for operatorsof passenger trains,
both public and private. Rolling stock costsare due to material
acquisition, power supply, and material maintenance. The efficient
circulation of rolling stock material is therefore one of the
objectives pursued. In this paper we focus on the circulation of train
units on a single line. In order to utilize the train units on this
line in an efficient way, they are added to or removed from the trains
in certain stations, according to the passengers
Business Modeling Framework For Personalization In Mobile Business Services
Is presented the structure of a formal framework for personalizationfeatures for mobile business services, which can be used to drive thebusiness modeling of M-business services from a service provider pointof view. It also allows to compute the revenue as linked topersonalization levels and features. A case study has been performedin the area of personalized location based mobile servicespersonalization;individual profiles;location based services;mobile business;mobile services
Entropic Regularization Approach for Mathematical Programs with Equilibrium Constraints
A new smoothing approach based on entropic perturbationis proposed for solving mathematical programs withequilibrium constraints. Some of the desirableproperties of the smoothing function are shown. Theviability of the proposed approach is supported by acomputationalstudy on a set of well-known test problems.mathematical programs with equilibrium constraints;entropic regularization;smoothing approach
Business Modeling Framework For Personalization In Mobile Business Services
Is presented the structure of a formal framework for personalization
features for mobile business services, which can be used to drive the
business modeling of M-business services from a service provider point
of view. It also allows to compute the revenue as linked to
personalization levels and features. A case study has been performed
in the area of personalized location based mobile service
Inventory strategies for systems with fast remanufacturing
We describe hybrid manufacturing/remanufacturing systems with a longlead time for manufacturing and a short lead time for remanufacturing.We review the classes of inventory strategies for hybrid systems inthe literature. These are all based on equal lead times. For systemswith slow manufacturing and fast remanufacturing, we propose a newclass. An extensive numerical experiment shows that the optimalstrategy in the new class almost always performs better and often muchbetter than the optimal strategies in all other classes.logistics;remanufacturing;stochastic inventory control
Shunting of Passenger Train Units in a Railway Station
In this paper we introduce the problem of shunting passenger trainunits in a railway station. Shunting occurs whenever train units aretemporarily not necessary to operate a given timetable. We discussseveral aspects of this problem and focus on two subproblems. Wepropose mathematical models for these subproblems together with asolution method based on column generation. Furthermore, a newefficient and speedy solution technique for pricing problems in columngeneration algorithms is introduced. Finally, we present computationalresults based on real life instances from Netherlands Railways.logistics;column generation;railway optimization;real world application