Attractiveness-based airline network models with embedded spill and recapture

Purpose: In airline revenue management, the modeling of the spill and recapture effects is essential for an accurate estimation of the passenger flow and the revenue in a flight network. However, as most current approaches toward spill and recapture involve either non-linearity or a tremendous amount of additional variables, it is computationally intractable to apply those techniques to the classical network design and capacity planning models. Design/methodology: We present a new framework that incorporates the spill and recapture effects, where the spill from an itinerary is recaptured by other itineraries based on their attractiveness. The presented framework distributes the accepted demand of an itinerary according to the currently available itineraries, without adding extra variables for the recaptured spill. Due to its compactness, we integrate the framework with the classical capacity planning and network design models. Findings: Our preliminary computational study shows an increase of 1.07% in profitability anda better utilization of the network capacity, on a medium-size North American airline provided by Sabre Airline Solutions. Originality/value: Our investigation leads to a holistic model that tackles the network design and capacity planning simultaneously with an accurate modeling of the spill and re- capture effects.Furthermore, the presented framework for spill and recapture is versatile and can be easily applied to other disciplines such as the hospitality industry and product line design (PLD) problems.Peer Reviewe

Method of projects in teaching Russian as a foreign language in Russian pedagogical university: to the problem of development of open educational space

The advantages of the method of projects in teaching Russian as a foreign language are proved in the article, as this method stimulates motivation, it realizes person-oriented approach and creates situation of “immersion” into the problem.В статье обосновываются преимущества проектного метода обучения русскому языку как иностранному, поскольку этот метод способствует повышению мотивации к изучению, реализации личностного подхода к обучению и созданию ситуации «погружения» в проблему

A simulation scenario based mixed integer programming approach to airline reserve crew scheduling under uncertainty

The environment in which airlines operate is uncertain for many reasons, for example due to the effects of weather, traffic or crew unavailability (due to delay or sickness). This work focuses on airline reserve crew scheduling under crew absence uncertainty and delay for an airline operating a single hub and spoke network. Reserve crew can be used to cover absent crew or delayed connecting crew. A fixed number of reserve crew are available for scheduling and each requires a daily standby duty start time. This work proposes a mixed integer programming approach to scheduling the airline’s reserve crew. A simulation of the airline’s operations with stochastic journey time and crew absence inputs (without reserve crew) is used to generate input disruption scenarios for the mixed integer programming simulation scenario model (MIPSSM) formulation. Each disruption scenario corresponds to a record of all of the disruptions that may occur on the day of operation which are solvable by using reserve crew. A set of disruption scenarios form the input of the MIPSSM formulation, which has the objective of finding the reserve crew schedule that minimises the overall level of disruption over the set of input scenarios. Additionally, modifications of the MIPSSM are explored, a heuristic solution approach and a reserve use policy derived from the MIPSSM are introduced. A heuristic based on the proposed MIPSSM outperforms a range of alternative approaches. The heuristic solution approach suggests that including the right disruption scenarios is as important as the quantity of disruption scenarios that are added to the MIPSSM. An investigation into what makes a good set of scenarios is also presented

Polyhedra Study of Mixed Integer Programs With Variable Upper Bounds

112 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2004.We investigate the convex hull of the set defined by a single constraint with continues and binary variables and in addition, variable upper bound constraints are present. We introduce the flow cover inequality, which is valid for a projection. We also give conditions under which this inequality is facet defining. We use sequence independent lifting to obtain valid inequalities for the entire set. In general, computing the lifting function is NP-hard, but under an additional restriction on the cover we obtain a closed form. In the second part of the thesis we first elaborate on general sequence dependent lifting for this set and present a dynamic program for calculating lifting coefficients. Then we consider projections of this set to knapsack cover and to the single binary variable polytope. We present the result of sequence independent lifting of the knapsack cover inequality and obtain lifting some coefficients for sequence dependent lifting with for specific sequences. We generate two new families of facet defining inequalities for the single binary variable polytope and prove that combined with the trivial inequalities they give a full description of this polytope. Finally, we give an optimization problem for the lifting coefficients.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Proper Names’ Semantics in Short Stories by A. Chekhov

В статье рассматриваются отдельные закономерности обыгрывания семантики собственных имен в контексте сюжетов ранних рассказов А. П. Чехова.Some issues of play on proper names in A. Chekhov’s shortstories are observed

The Discursive Oppositions Modelling as anAuthor’s Appraisal Method

The article analyses linguistic and cultural markers creating the author's appraisals in V. A. Shenderovich's works. The author focuses on the journalism created in 2012-2013. He founds out discourse oppositions of the reality modelling of Russia and abroad.Статья посвящена анализу лингвокультурных маркеров авторской оценки на материале публицистики В. А. Шендеровича. Автор анализирует заметки, опубликованные в 2012-2013 гг., и выявляет дискурсивные оппозиции, характерные для особенностей русской и зарубежной моделей действительности

Attractiveness-based airline network models with embedded spill and recapture

Purpose: In airline revenue management, the modeling of the spill and recapture effects is essential for an accurate estimation of the passenger flow and the revenue in a flight network. However, as most current approaches toward spill and recapture involve either non-linearity or a tremendous amount of additional variables, it is computationally intractable to apply those techniques to the classical network design and capacity planning models. Design/methodology: We present a new framework that incorporates the spill and recapture effects, where the spill from an itinerary is recaptured by other itineraries based on their attractiveness. The presented framework distributes the accepted demand of an itinerary according to the currently available itineraries, without adding extra variables for the recaptured spill. Due to its compactness, we integrate the framework with the classical capacity planning and network design models. Findings: Our preliminary computational study shows an increase of 1.07% in profitability anda better utilization of the network capacity, on a medium-size North American airline provided by Sabre Airline Solutions. Originality/value: Our investigation leads to a holistic model that tackles the network design and capacity planning simultaneously with an accurate modeling of the spill and re- capture effects.Furthermore, the presented framework for spill and recapture is versatile and can be easily applied to other disciplines such as the hospitality industry and product line design (PLD) problems.Peer Reviewe

Method of projects in teaching Russian as a foreign language in Russian pedagogical university: to the problem of development of open educational space

The advantages of the method of projects in teaching Russian as a foreign language are proved in the article, as this method stimulates motivation, it realizes person-oriented approach and creates situation of “immersion” into the problem.В статье обосновываются преимущества проектного метода обучения русскому языку как иностранному, поскольку этот метод способствует повышению мотивации к изучению, реализации личностного подхода к обучению и созданию ситуации «погружения» в проблему