Seat Assignment Research Articles

An online optimization-based procedure for the assignment of airplane seats

Due to the large number of air flights these days, all procedures involved in their operational management should be carefully optimized. This work presents a novel approach to the seat assignment problem, which focuses on deciding where to seat the passengers of different online purchases. This problem is currently solved by most airlines with a set of simple pre-defined rules that do not take into account future sales. Instead, the approach in this work is based on solving an integer multicommodity network flow problem, where different commodities are associated with expected future demands of different types of passengers. One feature of the developed optimization model is that it has to be solved online (that is, in real time), thus it must be both effective and fast, which prevented the use of more sophisticated (but also more time consuming, as it was experimentally observed) models based on stochastic programming. Using a real database of flights by Vueling Airlines S.A., we generated a set of synthetic online purchases simulating a pseudo-real flight. Applying our approach to this synthetic data, we observed that (1) the optimization model could be satisfactorily solved in real-time using the state-of-the-art CPLEX solver; (2) and the seat assignment obtained was of higher quality than that obtained by the simple pre-defined rules used by airlines.

Evaluating Classical Airplane Boarding Methods Considering COVID-19 Flying Restrictions

The novel coronavirus (SARS-CoV-2) has imposed the need for a series of social distancing restrictions worldwide to mitigate the scourge of the COVID-19 pandemic. This applies to many domains, including airplane boarding and seat assignments. As airlines are considering their passengers’ safety during the pandemic, boarding methods should be evaluated both in terms of social distancing norms and the resulting efficiency for the airlines. The present paper analyzes the impact of a series of restrictions that have been imposed or mooted worldwide on the boarding methods used by the airlines, featuring the use of jet-bridges and one-door boarding. To compare the efficacy of classical airplane boarding methods with respect to new social distancing norms, five metrics were used to evaluate their performance. One metric is the time to complete the boarding of the airplane. The other four metrics concern passenger health and reflect the potential exposure to the virus from other passengers through the air and surfaces (e.g., headrests and luggage) touched by passengers. We use the simulation platform in NetLogo to test six common boarding methods under various conditions. The back-to-front by row boarding method results in the longest time to complete boarding but has the advantage of providing the lowest health risk for two metrics. Those two metrics are based on passengers potentially infecting those passengers previously seated in the rows they traverse. Interestingly, those two risks are reduced for most boarding methods when the social distance between adjacent passengers advancing down the aisle is increased, thus indicating an unanticipated benefit stemming from this form of social distancing. The modified reverse pyramid by half zone method provides the shortest time to the completing boarding of the airplane and—along with the WilMA boarding method—provides the lowest health risk stemming from potential infection resulting from seat interferences. Airlines have the difficult task of making tradeoffs between economic productivity and the resulting impact on various health risks.

NEL MONDO DELLA GIUSTIZIA: FRATTURE E CONTINUITÀ TRA REGIME FASCISTA E ORDINAMENTO DEMOCRATICO


 Per quanto possa apparire paradossale, per alcuni decenni dopo la caduta del fascismo nel mondo della giustizia convivono radicali fratture rispetto al regime e ferrea continuità nella struttura ordinamentale, negli uomini (le donne entreranno in magistratura solo nel 1964) e nelle prassi operative della magistratura italiana. Per rendersi conto di quanto fosse profonda la contraddizione tra fratture e continuità converrà richiamare per sommi capi lo stato della giustizia nel regime fascista, che a sua volta si poneva in termini di sostanziale continuità con lo Stato liberale. La magistratura non godeva né dell’indipendenza esterna dal potere esecutivo, né dell’indipendenza interna dai vertici dell’organizzazione giudiziaria e dai capi degli uffici. In particolare, il pubblico ministero era in rapporto di diretta dipendenza dal Ministro della giustizia; quanto alla magistratura giudicante, i poteri relativi allo stato giuridico (ingresso in carriera, assegnazione della sede, trasferimenti, promozioni, incarichi direttivi, azione disciplinare) erano esercitati dal Ministro della giustizia o da commissioni di alti magistrati istituite presso il ministero. [continua]

OPESA: ONLINE PLATFORM FOR AUTOMATIC EXAM-HALL SEAT ALLOCATION

We present oPESA, an online examination management system for exam-hall seating arrangement. oPESA is a platform built on PHP, HTML, CSS, JavaScript, jQuery and SQL. It is an open platform which can be accessed only by registered users, i.e., professors and students. Professors provide as input course details like title, examination date and room; additional input, like predetermined lists of students or list of constraints regarding the seating plan, can also be given. Students simply register for course examinations by providing their student ID as input. Whenever a student registers for an examination, oPESA immediately responds by automatically assigning an exam-hall seat to the student. Seat assignment is performed by an unbiased algorithm ensuring randomness and fairness. Results appear online but can also be downloaded and saved locally in .xls format. oPESA follows a responsive web design which allows it to automatically resize, hide, shrink or enlarge in order to look good on all devices (desktop computers, tablets, smartphones). oPESA suggests a very useful management tool for modern - highly-populated - higher education institutes which significantly facilitates the examination management process offering clarity and efficiency. Furthermore, oPESA could be also used for more general seat allocation purposes in the context of scientific, social and cultural events.

Mathematical models of political districting for more representative governments

Political Districting, the problem of partitioning a geographical region into sub-regions as electoral districts for political seat assignment, has been widely studied by researchers of both social and mathematical sciences. In the US, one Congressional representative is elected for each such district, and the Constitution requires compactness, geographical contiguity, and population balance for any such district. “Gerrymandering,” i.e., misuse of re-districting once every 10 years (after each new census) to benefit a particular political party or current incumbent(s), has been practiced for decades, and political strongholds for individual parties have been formed. The vast majority, if not all, of the current literature and proposed software tools on political districting focus on how to achieve the non-political constitutional requirements. Election and re-districting are political processes; we believe that software tools are needed to achieve political purposes. In this paper, we present two mathematical optimization models to implement two new political criteria: fairness and competitiveness. Fairness aims to ensure fair allocation of seats to political parties considering the distribution of voters. Competitiveness aims to maximize the number of competitive districts to prevent districting solutions that provide clear advantage to one political party. We show that the feasibility problem associated with each of the two optimization models is NP-complete. Both models are implemented with a case study of South Carolina. The numerical results of six scenarios demonstrate their effectiveness and efficiency. A strategy is proposed to deal with the issue of computational complexity associated with a state that is partitioned into a large number of indivisible area/population units, e.g., census tracks, as building blocks of electoral districts. The two models can be extended or modified to address fairness and competitiveness issues in some political systems with three or more political parties.

Greedy Method for Boarding a Partially Occupied Airplane Using Apron Buses

This paper investigates the time to complete the boarding of a partially occupied two-door airplane when its passengers are transported from the airport terminal to the airplane using two apron buses. We propose a greedy method that assigns each passenger to a particular apron bus based on the passengers’ airplane seat assignments. This greedy approach exploits the airplane’s symmetry by providing essentially the same method for those boarding through the front door of the airplane as those boarding through the rear door of the airplane. The symmetrical properties of window, middle, and aisle seats of each row/side are considered in the proposed method as well. Computer simulation results indicate that, when using the greedy method, the boarding time can be reduced by up to 8.33% compared to the boarding time resulting from the best known practices in the literature, and with up to a 43.72% improvement in boarding time when compared to the boarding method commonly used in many airports. Furthermore, experimental results confirm our hypothesis that when the capacity of the apron buses exceeds the number of passengers to be transported to the airplane, the most time-efficient results of the proposed greedy method occur when an equal number of passengers are assigned to each of the two apron buses.

Relational Integration in Schools Through Seating Assignments

Traditional desegregation policies have improved but not fully solved the problems associated with the reproduction of inequalities and interracial prejudice in schools. This is partly because social networks are inherently segregated within integrated schools and the benefits of contact have not fully materialized. Therefore, new kinds of policies are needed to further improve the situation. This paper investigates the consequences and efficiency of seating arrangements on academic outcomes and prejudice using an agent-based model that reflects real-life asymmetries. We model interpersonal dynamics and study behavior in the classroomin the hypothetical case of a single teacher who defines students’ seating arrangements. The model incorporates the mechanisms of peer influence on study behavior, on attitude formation, and homophilous selection in order to depict the interrelated dynamics of networks, behavior, and attitudes. We compare various seating arrangement scenarios and observe how GPA distribution and level of prejudice changes over time. Results highlight the advantages and disadvantages of seating strategies. In general, more heterogeneous deskmate pairs lead to a lower level of inequality and prejudice in the classroom, but this strategy does not favor talent management. Further, we evaluate outcomes compared to the absence of external intervention whereby students choose their own deskmates based on homophilous selection. Our model takes into account the fact that homophilous selection may be distorted due to the ‘Acting White’ phenomenon and pre-existing prejudice. Accounting for these factors implies slower convergence between advantaged and disadvantaged students.

Investigating the Random Seat Boarding Method without Seat Assignments with Common Boarding Practices Using an Agent-Based Modeling

Research related to creating new and improved airplane boarding methods has seen continuous advancement, in recent years, while most of the airline companies have remained committed to the traditional boarding methods. Among the most-used boarding methods, around the world, are back-to-front and random boarding with and without assigned seats. While the other boarding methods used in practice possess strict rules for passengers’ behavior, random without assigned seats is dependent on the passengers own way of choosing the “best” seats. The aim of this paper is to meticulously model the passengers’ behavior, especially, in random boarding without assigned seats and to test its efficiency in terms of boarding time and interferences, in comparison with the other commonly-adopted methods (random boarding with assigned seats, window-middle-aisle (WilMA), back-to-front, reverse pyramid, etc.). One of the main challenges in our endeavor was the identification of the real human passengers’ way of reasoning, when selecting their seats, and creating a model in which the agents possess preferences and make decisions, as close to those decisions made by the human passengers, as possible. We model their choices based on completed questionnaires from three hundred and eighty-seven human subjects. This paper describes the resulting agent-based model and results from the simulations.

A seat assignment model for high-speed railway ticket booking system with customer preference consideration

ABSTRACTThis paper addresses the railway revenue management problem of homogeneous seats. Within a certain period of time, multiple trains characterized by different train stop plans are alternatives to each other. For homogeneous seats, multiple fare classes are designed based on the customer preference orders of different customer types. A seat inventory control method is developed based on characteristics of the China high-speed railway (HSR). In addition, an efficient heuristic approach is proposed to solve the nonlinear integer programming model of the HSR revenue management problem. The Beijing-Shanghai HSR is taken as a case study. Numerical examples show that revenue can be increased by reasonably controlling the deterministic booking limits of different fare classes according to customer preference orders. Furthermore, our method can increase the total revenue by optimizing the resources of multiple trains with different train stop plans.

Robust Optimization of Airplane Passenger Seating Assignments

We present a method that reduces the time it takes to complete the passenger boarding of an airplane. In particular, we describe a two-stage mixed integer programming (MIP) approach, which assigns passengers to seats on an airplane based on the number of bags they carry aboard the plane. The first stage is an MIP that assigns passengers to seats to minimize the time to complete the boarding of the plane. The second-stage MIP also determines seating assignments, while constraining the total boarding time to that determined by the stage-one MIP and maximizing weighted slack times to provide a more robust assignment. Numerical results show that this two-stage approach results in lower average boarding times than the one-stage approach, when the time it takes passengers to walk and sit in their seats is random. Experiments indicate that the magnitude of the improvement is not very sensitive to variations in the slack time weights.

An analysis of ongoing trends in airline ancillary revenues

This paper examines the performance of the two core classifications of airline ancillary revenues, which are unbundled products and commission based income. It also investigates the willingness of passengers to pay (WTP) for these services together with what type of ancillary items are acceptable at a particular price point. The study found that passengers value a narrow range of perceived ‘necessity’ products and services such as food and drink, checked baggage and seat assignment as opposed to perceived ‘optional’ unbundled or commission based products/services. It also found significant differences in WTP for specific ancillary services based on carrier type (FSC/LCC/Charter), length of flight (long and short haul) and journey purpose (business, leisure, VFR).

2G22 学生と教員の意欲向上のための教育環境の改善 : 演習の教授法,座席指定,スマートフォン対策((13)教育評価・自己点検・評価システム-II,口頭発表)

2G22 学生と教員の意欲向上のための教育環境の改善 : 演習の教授法,座席指定,スマートフォン対策((13)教育評価・自己点検・評価システム-II,口頭発表)

Implications of seat assignment flexibilization for airline revenue management

This paper aims to prompt the airline industry to explore a new way of using existing airline cabin layouts that improves profitability and comfort. The century old paradigm, that passengers take a seat for an entire flight, is a way of utilizing airliner cabins that heuristically means poor comfort for most passengers and low financial returns (Return on Invested Capital – Weighted Average Capital Cost industry wide of −2.3 per cent (2013) and −1.2 per cent (2014), and EBIT of 3.5 per cent (2013) and 5.1 per cent (2014) of revenues Earnings Before Interest and Tax) – Source IATA). The author shows the benefits of allowing a place-exchange market to operate during flights. This market proves to be a superior value extraction tool and opportunity for airlines, which can substantially increase their profits by enabling widespread comfort to their customers. As a consequence, airline economics are greatly improved. As a corollary, this dramatically increases the amount of viable routes.

Who brings home the pork? Parties and the role of localness in committee assignments in mixed-member proportional systems

The assignment of seats to specialized standing committees is a most consequential choice in legislative contexts. Distributive theories of legislative organization suggest that electoral incentives to cultivate personal votes result in the self-selection of legislators to committees best suited to please their constituents and, thus, to secure reelection. However, these theories discard the partisan basis of European parliaments and therefore fail to adequately assess the politics of committee assignments in these particular contexts. This article aims to explore the significance of distributive theories for the German case in differentiated ways and on the basis of a new and rich data set including statistical data for five legislative terms (1983, 1987, 1998, 2005, and 2009). It argues that in partisan assemblies, political parties might develop an interest in distributive politics themselves and might assign distinct types of legislators to distinct committees to seek personal votes contingent upon distinct electoral incentives. Particularly, we argue that Germany’s mixed proportional system provides incentives to parties to assign legislators with profound local roots to district committees best suited to please geographic constituents.

Mechanism behind phase transitions in airplane boarding process

A simple airplane boarding model is built much like an asymmetric exclusion process (ASEP). The dynamics of the model is constrained by local interference between passengers and global seat assignments for individuals. We perform extensive Monte Carlo simulations by using a parallel update rule to determine quantities like boarding time and sequence correlation. Our results clarify the scaling behavior in boarding process and identify a critical value of arrival time interval for boarding time threshold. Three different phases (steady, intermediate and linear) with respect to the boarding time are distinguished and the mechanism behind phase transition is further discussed.

A fast airplane boarding strategy using online seat assignment based on passenger classification

The minimization of the turnaround time, the duration which an aircraft must remain parked at the gate, is an important goal of airlines to increase their profitability. This work introduces a procedure to minimize of the turnaround time by speeding up the boarding time in passenger aircrafts. This is realized by allocating the seat numbers adaptively to passengers when they pass the boarding gate and not before. Using optical sensors, an agility measure is assigned to each person and also a measure to characterize the size of her/his hand-luggage. Based on these two values per passenger and taking into account additional constraints, like reserved seats and the belonging to a group, a novel seat allocation algorithm is introduced to minimize the boarding time. Extensive simulations show that a mean reduction of the boarding time with approximately 15% is achieved compared to existing boarding strategies. The costs of introducing the proposed procedure are negligible, while the savings of reducing the turnaround time are enormous, considering that the costs generated by inactive planes on an airport are estimated to be about 30 $ per minute.

Seat Assignment Model for Student Admissions Process at Saudi Higher Education Institutions

Seat Assignment Model for Student Admissions Process at Saudi Higher Education Institutions

Peer Effects in Microenvironments: The Benefits of Homogeneous Classroom Groups

Many believe that classroom interactions play an important role in students’ academic achievement, but there is little evidence on peer effects within subclassroom groups. We exploit random seat assignment in a Chinese middle school to estimate how the gender of neighboring students affects a student’s academic achievement. We find that being surrounded by five females rather than five males increases a female’s test scores by 0.2–0.3 standard deviations but has no significant effects on a male’s test scores. These results suggest a low-cost way to potentially improve performance within the world’s largest school system.

Network flow methods for electoral systems

AbstractResearchers in the area of electoral systems have recently turned their attention to network flow techniques with the aim to resolve certain practically relevant problems arising in this area. The aim of this paper is to review some of this work, showing the applicability of these techniques even to problems of a very different nature. Major emphasis will be placed on “biproportional apportionment,” a problem that frequently arises in proportional electoral systems, but which in some countries is still ill‐solved, or not dealt with rigorously, notwithstanding the availability of several sound solution procedures and their concrete application in some real‐life elections. Besides biproportional apportionment, we shall discuss applications of network flows to problems such as vote transitions and political districting. Finally, we address the so‐called “give‐up problem,” which arises in the current elections for the Italian Parliament. It is related to the possible assignment of seats to multiple winners of a given party. Based on the results and techniques presented in this article, it is fair to state that network flow models and algorithms are indeed very flexible and effective tools for the analysis and the design of contemporary electoral systems. © 2011 Wiley Periodicals, Inc. NETWORKS, 2012

Assessment of product debundling trends in the US airline industry: Customer service and public policy implications

This paper reviews product debundling trends that have occurred in the US airline industry. Multiple sources of ancillary fees related to ticketing refunds and exchanges, checked baggage, on-board pets, preferred and/or advanced seating assignments, frequent flyer ticket redemptions, and day of departure standby policies are reviewed. Despite the fact that both low cost and network carriers stress the importance of future ancillary fees in their investor reports, our assessment suggests that these fees will be more broadly adopted by low cost carriers. We anticipate that many network carriers will eliminate ancillary fees, particularly as they begin to recognize how these fees can impact other system performance objectives such as minimizing the number of misconnecting passengers. We estimate that the debundling phenomenon has diluted revenues to the US Airport and Airways Trust Fund by at least 5%.