Journal articles on the topic 'Airline Software Applications'

Big Data technologies have significantly increased the possibility for sellers to adopt personalisation strategies, especially in digital markets. Among such strategies, price discrimination, a practice where the same commodity is sold at different prices, either to the same customer or to different customers, stands out. Particularly, the online airline ticket market has risen the attention of economists in recent studies, both because of its specificity and of the high data availability. This manuscript enters the debate and analyses the airline ticket market in an original way. Indeed, the aim of this work is to empirically understand whether some airline companies discriminate in prices by using the customers’ data that they collect from their websites, and, if so, which is the impact on social welfare. For performing this assessment, a software that is able to automatically collect pricing data is developed and freely released. By executing the software in two time periods, tickets prices of three airlines, three itineraries, and four different user profiles are acquired. A double analysis is performed to check if customers’ information are used to discriminate (intra-user), and if different prices are offered to distinct user profiles (inter-user). Moreover, the analyses consider control data collected from the API of the Global Distribution System Amadeus, the main flight booking platform dedicated to travel agents. Upon inspection, no evidence is found in this study to support the hypothesis that airlines use price discrimination techniques.

Purpose The purpose of this paper is to evaluate the hotel selection problem of airlines for their hotel and airline alliance (HAA) to develop potential customers of airlines. This paper will propose a hybrid mathematics evaluation model to help airline to select an optimal hotel with both qualitative and quantitative criteria. Design/methodology/approach To solve the hotel selection problem of airlines for their HAA, this paper focuses on the implementation of the NGT, Fuzzy TOPSIS and MCGP models in the hotel selection process. Initially, the NGT was used to create HAA decision-making criteria based on the literature review and expert opinions, and it was found that scale and scope possibility, brand value, tourism attraction, operating cost and industrial conditions are the most important criteria. Later, the Fuzzy TOPSIS method was used to obtain the general normalized fuzzy preference and to compute the closeness coefficients of each alternative hotel with respect to each criterion. Third, five tangible constraints were incorporated into the Fuzzy TOPSIS-MCGP model to calculate the optimal hotel with LINGO software. Findings Airline managers can use the proposed model to form a clear view of how to choose the most suitable hotel to cooperate with to outperform their competitors. Having access to this information allows airline managers to take steps to perform better and improve the performance of the partnership, helping them to gain more confidence in their decision-making capabilities while reducing investment risks. Originality/value This is the first paper that has adopted Fuzzy TOPSIS-MCGP to select hotel for their HAA from the airline’s point of view. The major contributions of this study are as follows: an efficient and simple evaluation framework is proposed for handling vagueness and uncertainty in real-world hotel selection problems; the advancement of treating uncertainty in the MCDM process; the fuzzy TOPSIS-MCGP method is extended for such problems, taking into account tangible and intangible criteria; airline managers can now make decisions in choosing to select the best hotel for their HAA that meets the airline's business goals and passenger demands; hotel operators are flexible in selecting their airline partnership, thus creating greater profit for both parties.

Mobile phone usage and its adoption have been growing at exponential rates. It is this exponential growth rate that has led many to predict Mobile Commerce (M-Commerce) as the next major evolution of Electronic Commerce (E-Commerce). While M-Commerce comes rich with unique features, it is currently lacking in usage when compared to traditional e-commerce. There are many challenges that must be addressed in this respect. These challenges are mostly inherent in the mobile devices, communication network, legal and regulatory infrastructure. The use of agents in e-commerce has long been explored in the context, resulting in a number of agent based e-commerce systems. It is not surprising then to note that many researchers believe that the problems that the M-Commerce now faces can be addressed well using agent technology. While there is an abundance of information on the use of agent based systems in other areas, there has been no great surge yet in the use of agent based systems in real world M-Commerce applications. We believe that this slow adoption of this agent technology is due to a lack of standards. There has been a quite an amount of research work carried out in the use of software intelligent agents in the M-Commerce applications like Shopping, Hotel, and Airline industries. These are outlined in the paper with appropriate screenshots and descriptions.

The current study is intended to provide analysis of the direct and indirect relationships between (E-HRM) strategies and organizational innovation through knowledge repository as a mediation construct. From various previous studies, five (E-HRM) strategies constructs were adopted for this study. These include E- recruitment, e- selection, e-training, e- performance appraisal, and e-compensations, and used the mediating role of a knowledge repository for these constructs to improve organizational innovation. The study applied the smart partial least square (PLS) software to analyse the underlying relationships amongst the most relevant constructs between (E-HRM) strategies, knowledge repositories, and organizational innovation with a total of seven constructs. The results are from top, middle managers (n = 94) working in the Royal Jordanian airline. It was found that there was a strong and statistically positive significant relationship between several (E-HRM) strategies and organizational innovation by using the knowledge repository as a mediation construct.

This chapter is about an important tool in the data science workbench, Bayesian networks (BNs). Data science is about generating information from a given data set using applications of statistical methods. The quality of the information derived from data analysis is dependent on various dimensions, including the communication of results, the ability to translate results into actionable tasks and the capability to integrate various data sources [R. S. Kenett and G. Shmueli, On information quality, J. R. Stat. Soc. A 177(1), 3 (2014).] This paper demonstrates, with three examples, how the application of BNs provides a high level of information quality. It expands the treatment of BNs as a statistical tool and provides a wider scope of statistical analysis that matches current trends in data science. For more examples on deriving high information quality with BNs see [R. S. Kenett and G. Shmueli, Information Quality: The Potential of Data and Analytics to Generate Knowledge (John Wiley and Sons, 2016), www.wiley.com/go/information_quality.] The three examples used in the chapter are complementary in scope. The first example is based on expert opinion assessments of risks in the operation of health care monitoring systems in a hospital environment. The second example is from the monitoring of an open source community and is a data rich application that combines expert opinion, social network analysis and continuous operational variables. The third example is totally data driven and is based on an extensive customer satisfaction survey of airline customers. The first section is an introduction to BNs, Sec. 2 provides a theoretical background on BN. Examples are provided in Sec. 3. Section 4 discusses sensitivity analysis of BNs, Sec. 5 lists a range of software applications implementing BNs. Section 6 concludes the chapter.

This paper analyses the impact of airline business models on airport infrastructure and operational capacity and answers the question how to optimize capacity in order to achieve maximum efficiency and profitability as well as how to maintain an adequate level of service quality. As part of the research, a new model was created as an integral part of the Airport Management Strategy Software (AMSS) application. The purpose of the application is to enable the airport management to review and optimize operations in terms of maximum technical and technological capacity utilization. In addition, the application can be used to fill the available slots according to the specifics of the airline’s business model without compromising the security, flexibility, and profitability of airport operations. The validation of the application was conducted at Zagreb Airport, which generated traffic of 3.4 million passengers in 2019. The result of the research is a model which, based on the calculation of the existing capacity of the airport infrastructure and ground handling equipment, enables the simulation of new airline business models and aircraft type implementation. Furthermore, the model also analyses their impact on the utilization of the airport infrastructure and equipment. The research demonstrated the interdependence between airport capacity optimization and optimal slot allocation, and the specifics of airline business models and aircraft types in their fleets. By adopting this model, airport managers can prevent mistakes that arise during negotiations with airlines, which can result in the under capacity of the infrastructure, equipment, and human resources as well as cause lower levels of security, numerous delays, reduced quality of service and, ultimately, negative financial effects.

PurposeFractional calculus provides powerful tool to build more realistic and accurate mathematical models in economic field. This paper aims to explore a proposed fractional-order differentiated Cournot duopoly game and its discretized game.Design/methodology/approachConditions for existence and uniqueness of the proposed game’s solution are derived. The existence of Nash equilibrium point and its local and global stability are obtained. Furthermore, local stability analysis of the discretized game is investigated. The effects of fractional-order on game’s dynamics are examined, along with other parameters of the game, via the 2D bifurcation diagrams in planes of system’s parameters are acquired.FindingsTheoretical and numerical simulation results demonstrate rich variety of interesting dynamical behaviors such as period-doubling and Neimark–Sacker bifurcations, attractors’ crises in addition to chaotic attractors. The results demonstrated that the stability Nash equilibrium point of the game can be lost by period doubling or Neimark–Sacker bifurcations.Practical implicationsOligopoly games are pivotal in the mathematical modeling of some substantial economic areas such as industrial organization, airline, banking, telecommunication companies, international trade and also macroeconomic analysis of business cycles, innovation and growth.Originality/valueAlthough the Cournot game and its variants have attracted great interest among mathematicians and economists since the time of its proposition till present, memory effects in continuous-time and discrete-time Cournot duopoly game have not been addressed yet. To the best of author’s knowledge, this can be considered as the first attempt to investigate this problem of fractional-order differentiated Cournot duopoly game. In addition, studying more realistic models of Cournot oligopoly games plays a pivotal role in the mathematical investigation and better understanding of some substantial economic areas such as industrial organization, airline, banking, telecommunication companies, international trade and also in macroeconomic analysis of business cycles, innovation and growth.

The air transportation domain faces issues in air traffic congestion which leads to delays affecting a network of flights. As stakeholders strive to address such issue by applying air traffic flow management (ATFM) actions, there exists an apparent divide in the solution objective and perspectives. In the extant literature, solution approaches involving ATFM actions are often framed from the perspective of only one stakeholder to another. Such a scheme does not comprehensively cover the overall goal of the stakeholders, thus, provides inadequate, even conflicting, solutions. Therefore, this paper proposes an integer linear programming model for a rerouting problem that satisfactorily incorporates the individual interests of stakeholders (i.e., airport management, airline sector, air traffic management) in the commercial aviation industry and the common goal of ensuring safety in flight operations. The proposed model is designed to tactically select an alternate route when the primary route is constrained due to uncertainties such as inclement weather in a post-departure scenario. A hypothetical case study involving multiple destinations and alternate routes is carried out to illustrate the validity of the model. A Demo version of Lingo software is used to run the proposed model. Notable computational results show significant differences of selected routes as individual system interests are taken into isolation compared to when the general, collaborative model is implemented. In other words, the proposed model is able to show that preferences in alternate routes do vary with the individual interests of stakeholders, more so with the integration of the collaborative decision among stakeholders. Therefore, this research work provides a groundwork to a more comprehensive take of managing air traffic scenario involving all phases of flights. This is realized by providing a proof that significant shifts of decision solutions occur when the overall goal of stakeholders is considered rather than taking their individual interests into isolation.

In order to achieve high safety standards, avionic software needs to be developed with very high requirements regarding safety, reliability, and determinism as well as real-time constraints, which are often in conflict with the development of maintainable software systems. Nevertheless, the ability to change the software of an airplane is of increasing importance, since it consists of a multitude of partially hardware-specific subsystems which may need replacement during a plane’s lifespan of typically numerous decades. Thus, as a first step towards optimizing maintainability of avionic software we have benchmarked the cabin software of a commercial airliner with common software metrics. Such a benchmarking of avionic software contributes valuable insights into the current practice of developing critical software and the application of software metrics in this context. We conclude from the obtained results that it is important to pay more attention to long-term maintainability of aviation software. Additionally we have derived some initial recommendations for the development of future avionic software systems.

General aviation, is refers to the civil aviation activities that is used a civil aircraft engaged in outside of public air transport, including industry, agriculture, forestry, fisheries and homework flight of the construction industry and medical and health, disaster relief, meteorological observation, ocean monitoring, scientific experiment, education and training, culture and sports and other party and flight activities. Therefore, every airline is necessary to set up its own set of flight operation control system. This paper introduces the concept of flight operation control system, system structure and functions of each module, and is given flight operation control system application solutions; provide reference for improving the flight operation and management level in our country.

KLM Royal Dutch Airlines has been using the General Electric ground-based engine monitoring (GEM) system for the CF6-50 and CF6-80 engines for several years. During the last year, various additional elements of the monitoring system have been introduced to the maintenance departments and are currently operational. This paper describes the introduction and the application of the GEM system within KLM’s organization. Also some attention is given to the (potential) benefits that are related to the use of this system, as well as to KLM’s engine monitoring plans for the near future.

Using interactive virtual simulation methods and combining numerical calculation software, the 3D airline emergency evacuation simulation system is established in Virtools platform according to the received data. The system takes full account of the passengers' individual differences during the evacuation process, setting up different member parameters, which influence the passengers evacuation behavior. In order to fulfill the different types of evacuation requirements in various simulation, it can change evacuation path algorithm, cabin layout data and evacuees component parameters, to get the corresponding evacuation simulation results. Meanwhile, the system interface can change visual angle to realize human-machine interaction freely and reflect the evacuation of the evacuation process accurately. Also the reliability of the system simulation result is verified by compared with the results of actual certification trial.

The extent of formal verification methods applied in industrial projects has always been limited. The proliferation of distributed ledger systems (DLS), also known as blockchain, is rapidly changing the situation. Since the main area of DLSs’ application is the automation of financial transactions, the properties of predictability and reliability are critical for implementing such systems. The actual behavior of the DLS is largely determined by the chosen consensus protocol, which properties require strict specification and formal verification. Formal specification and verification of the consensus protocol is necessary but not sufficient. It is also required to ensure that the software implementation of the DLS nodes complies with this protocol. Finally, the verified software implementation of the protocol must run on a fairly reliable operating system. The financial focus of DLS application has also led to the emergence of the so-called smart contracts, which are an important part of the applied implementations of specific business processes based on DLSs. Therefore, the verifiability of smart contracts is also a critical requirement for industrial DLSs. In this paper, we describe an ongoing industrial project between a large Russian airline and three universities – Innopolis University (IU), Moscow Institute of Physics and Technology (MIPT) and Lomonosov Moscow State University (MSU). The main expected project result is a DLS for more flexible refueling of aircrafts, verified at least at the four technological levels described above. After brief project overview, we focus on our experience with the formal specification and verification of HotStuff, a leader-based fault-tolerant protocol that ensures reaching distributed consensus in the presence of Byzantine processes. The formal specification of the protocol is performed in the TLA+ language and then verified with a specialized TLC tool to verify models based on TLA+ specifications.

In this paper, we present the procedure of estimating the aerodynamic coefficients for a commercial aviation aircraft from geometric parameters at low-cruise-flight conditions using US DATCOM (United States Data Compendium) and XFLR software. The purpose of this research was to compare the stability parameters from both pieces of software to determine the efficacy of software solution for a wide-body aircraft at the stated flight conditions. During the initial phase of this project, the geometric parameters were acquired from established literature. In the next phase, stability and control coefficients of the aircraft were estimated using both pieces of software in parallel. Results obtained from both pieces of software were compared for any differences and the both pieces of software were validated with analytical correlations as presented in literature. The plots of various parameters with variations of the angle of attack or control surface deflection have also been obtained and presented. The differences between the software solutions and the analytical results can be associated with approximations of techniques used in software (the vortex lattice method is the background theory used in both DATCOM and XFLR). Additionally, from the results, it can be concluded that XFLR is more reliable than DATCOM for longitudinal, directional, and lateral stability/control coefficients. Analyses of a Boeing 747-200 (a wide-body commercial airliner) in DATCOM and XFLR for complete stability/control analysis including all modes in the longitudinal and lateral directions have been presented. DATCOM already has a sample analysis of a previous version of the Boeing 737; however, the Boeing 747-200 is much larger than the former, and complete analysis was, therefore, felt necessary to study its aerodynamics characteristics. Furthermore, in this research, it was concluded that XFLR is more reliable for various categories of aircraft alike in terms of general stability and control coefficients, and hence many aircraft can be dependably modeled and analyzed in this software.

Flight delay is the most common preoccupation of aviation stakeholders around the world. Airlines, which suffer from a monetary and customer loyalty loss, are the most affected. Various studies have attempted to analyze and solve flight delays using machine learning algorithms. This research aims to predict flights’ arrival delay using Artificial Neural Network (ANN). We applied a MultiLayer Perceptron (MLP) to train and test our data. Two approaches have been adopted in our work. In the first one, we used historical flight data extracted from Bureau of Transportation Statistics (BTS). The second approach improves the efficiency of the model by applying selective-data training. It consists of selecting only most relevant instances from the training dataset which are delayed flights. According to BTS, a flight whose difference between scheduled and actual arrival times is 15 minutes or greater is considered delayed. Departure delays and flight distance proved to be very contributive to flight delays. An adjusted and optimized hyperparameters using grid search technique helped us choose the right architecture of the network and have a better accuracy and less error than the existing literature. The results of both traditional and selective training were compared. The efficiency and time complexity of the second method are compared against those of the traditional training procedure. The neural network MLP was able to predict flight arrival delay with a coefficient of determination R 2 of 0.9048, and the selective procedure achieved a time saving and a better R 2 score of 0.9560. To enhance the reliability of the proposed method, the performance of the MLP was compared with that of Gradient Boosting (GB) and Decision Trees (DT). The result is that the MLP outperformed all existing benchmark methods.

The article deals with the current issues of information and communication technologies and their touristindustry application. Nowadays, tourist service activity is inconceivable without information resources and communication technologies, which serve to equip the consumer with e-information transmission and acquisition tools. The author identified the following information service aspects that are valuable for the tourist industry: information as a link for the activity in tourism and service provision; tourism information product consumers (tourists, travel agencies, hotels, restaurants, airlines, railway and nautical companies, car-rent firms, etc); information resources (accounting databases, data provided by transfer companies); information owners and information resources; information systems; reservation and sales systems; information processes such as, for example, registration procedures, information transmission procedures, information processing procedures, and top management decision-making procedures; information system and technology support and maintenance – software provision, technical, linguistic, legal and organizational resources to ensure the operation of computering machines, thesauri, as well as operational instructions and methodology. The research conducted by the author leads to the general conclusion that, the newly-evolved information service industry is to continue its development and technological improvement, which, in its turn, will facilitate operations in the sphere of tourism and will satisfy consumer demand more efficiently.

Purpose – Accurate forecasting of intermittent demand is very important since parts with intermittent demand characteristics are very common. The purpose of this paper is to bring an easier way of handling the hard work of intermittent demand forecasting by using commonly used Excel spreadsheet and also performing parameter optimization. Design/methodology/approach – Smoothing parameters of the forecasting methods are optimized dynamically by Excel Solver in order to achieve the best performance. Application is done on real data of Turkish Airlines’ spare parts comprising 262 weekly periods from January 2009 to December 2013. The data set are composed of 500 stock-keeping units, so there are 131,000 data points in total. Findings – From the results of implementation, it is shown that using the optimum parameter values yields better performance for each of the methods. Research limitations/implications – Although it is an intensive study, this research has some limitations. Since only real data are considered, this research is limited to the aviation industry. Practical implications – This study guides market players by explaining the features of intermittent demand. With the help of the study, decision makers dealing with intermittent demand are capable of applying specialized intermittent demand forecasting methods. Originality/value – The study brings simplicity to intermittent demand forecasting work by using commonly used spreadsheet software. The study is valuable for giving insights to market players dealing with items having intermittent demand characteristics, and it is one of the first study which is optimizing the smoothing parameters of the forecasting methods by using spreadsheet in the area of intermittent demand forecasting.

The subject of research is the development of a method for constructing WEB-services based on cartographic models of airports for organizing passenger flows in conditions of quarantine zoning. The object of the research is the process of managing passenger flows at airports. The objective of the work is to improve the organization of passenger traffic at airports under quarantine conditions with the use of WEB-services based on cartographic models of airport buildings. Conclusions. Using the analysis results of the world's airports activities over the past five years, a steady trend has been revealed towards an increase of the number of flights, and, consequently, growth of the passenger traffic at airports. Also forecasts of air traffic development trends in Europe in the next five years are analyzed, which indicate the direction towards the growth of air traffic. An analysis of the quarantine restrictions impact in connection with the spread of COVID-19 was carried out, which showed that, despite a significant decrease in passenger traffic at airports in the world due to quarantine restrictions, there will be a significant increase in passenger traffic after quarantine relief. Based on the above, it was concluded that it is urgent to improve the organization of passenger traffic at airports under quarantine conditions through the use of WEB-services based on cartographic models of airport buildings. At the same time, the feasibility of using GIS technologies at airports analysis was made, as well as a review of modern information technologies that are currently used to organize the operation of airports in conditions of quarantine zoning. A method for constructing routes for organizing passenger flows at airports in conditions of quarantine zoning has been developed. The methodology envisages for the creation of airports passenger traffic maps using the most modern cartographic software products ArcGIS and ArcGIS Online, it contains recommendations for using a billing Wi-Fi network to track the movement of passengers in airport buildings, and, finally, envisages for the creation of WEB services for cartographic models of airports terminals. Developed with the use of proposed methodology, WEB-services for organizing passenger flows at airports in conditions of quarantine zoning, are convenient and ergonomic in terms of usage by workers of airports and airlines. Moreover, passengers can also quickly receive partial information sufficient to organize their movement in the airport terminal in accordance with quarantine restrictions.

Purpose The purpose of this paper is to assess the impact of additive manufacturing (AM) implementation on aircraft supply chain (SC) networks. Additive and conventional manufacturing spare part inventory control systems are studied and compared, revealing insights into SC performance. Design/methodology/approach A leading global commercial airline’s SC network data are used to model the research problem. A system dynamics simulation approach is followed, drawing out insights for managers. Findings A significant improvement in SC efficiency is observed through the implementation of AM, rendering it a worthwhile investment for global SCs. AM helps to balance inventory levels, and increase responsiveness while decreasing disruptions and carbon emissions in the supply networks. Practical implications The paper offers guidance on the adaption of AM in aircraft SCs and AM’s impact on spare part inventory systems. Originality/value The study provides robust evidence for making critical managerial decisions on SC re-design driven by a new and disruptive technology. Next-generation SC and logistics will replace the current demand for fulfilling material products by AM machines.

Sustained implementation of the optimization processes of the airlines commercial activities is indispensable for timely and appropriate business decisions. Development of the commercial air transport make necessary the standardization of the documents, regulatory issues and procedures followed by different modes of commercial agreements. It is especially present when itinerary of the journey includes at least two different air carriers. The modes of commercial cooperation are very different from the simple one to the very sophisticated and complex activities asking for harmonization of many elements and functional areas. It includes special prorate agreements which harmonize the revenue share between the air companies after the negotiations. Next level of the cooperation are code sharing agreements more and more present in business practice. Same conclusion is valid for joint venture agreements. The highest level of the cooperation are airline alliances which are analysed with the most recent results and indicators. Airlines are recognized leaders in implementation of modern information technologies with very sophisticated applications, data platforms and software solutions. Therefore, it is very important to follow and implement trends in e-commerce activities including e-marketing, e-sales and distribution and use of different on line and mobile platforms.

Delays in flights have negative socio-economics effects on passengers, airlines and airports, resulting to huge economic loses. Therefore, their prediction is crucial during the decision-making process for all players of aviation industry for proper management. The development of accurate prediction models for flight delays depend on the complexity of air transport system and airport infrastructure, hence may be country specific. However, there exists no prediction models tailored to Kenyan aviation industry. Hence there is need to develop prediction models amenable to Kenya aviation conditions. The objective of this study was to compare the prediction power of the developed models. Secondary data from Jomo Kenya International Airport (JKIA) was used in this study. The data collected included the day of the flight (Monday to Sunday), the month (January to December), the airline, the flight class (domestic or international), season (summer or winter), capacity of the aircraft, flight ID (tail number) and whether the flight had flown at night or during the day. The analysis of the data was done using R- software. Three models, Logistic model, Support Vector Machine model and Random Forest model, were fitted. The strength and utility of the models was determined using bias-variance learning curves. The study revealed that the models predicted delays with different accuracies. The Random Forest model had a prediction accuracy of 68.99% while the Support Vector Machine model (SVM) had an accuracy of 68.62% and the Logistic Regression model had an accuracy of 66.18%. The Random Forest model outperformed the SVM and Logistic Regression with accuracies of 0.37% and 2.71% respectively. The SVM and Random Forest do not assume probability distribution of the response under investigation, probably indicating why they performed better than the logistic regression. The study recommends application of Random Forest model to predict flight delays at JKIA.

The paper deals with the issue of Local Departure Control System (further only DCS) and its application in the airport environment. The authors submit their own DCS system solution supported by the Slovak Research and Development Agency under the contract no. VEGA-15-0527. The aim of the project was to design and then implement a solution that would meet the highest criteria of reliability, safety, and usability of the proposed solution in the field of its deployment. The primary target groups are local carriers, airlines, and airports operating in Slovakia with a special focus on regional low-cost companies and charter companies. Within the implementation of the project, algorithms of provided functions and activities of individual software modules were designed. Subsequently, the DCS hardware elements were optimally dimensioned, programmed, tested and tuned for the correct application code for the DCS system modules, as well as for CKI, Gate and PNL terminals.

In this paper, a novel combination method is offered to integrate the results of two new relative closeness models, called relative closeness benevolent (RCB) and relative closeness aggressive (RCA) models, for ranking all DMUs. To prove the applicability of the proposed method, it is examined in three numerical examples, performance assessment problem, six nursing homes and fourteen international passenger airlines. Firstly, RCB and RCA models were formulated in order to generate the cross-efficiency intervals matrix (CEIM). After obtaining CEIM, the RC index was utilized to generate a combined cross-efficiency matrix (combined CEM). In combined CEM, target DMUs were viewed as criteria and DMUs were viewed as alternatives. After that, the weights of each criterion were generated using a new weighting method based on standard deviation technique (MSDT). Finally, all DMUs were evaluated and ranked. Comparison with existing cross-efficiency models indicates the more reliable results through the use of the proposed method.

0. IntroductionIf we follow the line of much literature surrounding airports and urban mobility, the emphasis often falls on the fact that these spaces are designed to handle the mega-scale and super-human pace of mass transit. Airports have rightly been associated with velocity, as zones of rapid movement managed by enormous processing systems that guide bodies and things in transit (Pascoe; Pearman; Koolhaas; Gordon; Fuller & Harley). Yet this emphasis tends to ignore the spectrum of tempos and flows that are at play in airport terminals — from stillness to the much exalted hyper-rapidity of mobilized publics in the go-go world of commercial aviation.In this photo essay I'd like to pull a different thread and ask whether it's possible to think of aeromobility in terms of “uneven, differential mobility” (Bissell 280). What would it mean to consider waiting and stillness as forms of bodily engagement operating over a number of different scales and temporalities of movement and anticipation, without privileging speed over stillness? Instead of thinking mobility and stillness as diametrically opposed, can we instead conceive of them as occupying a number of different spatio-temporal registers in a dynamic range of mobility? The following is a provisional "visual ethnography" constructed from photographs of air terminal light boxes I have taken over the last five years (in Amsterdam, London, Chicago, Frankfurt, and Miami). Arranged into a "taxonomy of differentiality", each of these images comes from a slightly different angle, mode or directionality. Each view of these still images displayed in billboard-scale light-emitting devices suggests that there are multiple dimensions of visuality and bodily experience at play in these image-objects. The airport is characterized by an abundance of what appears to be empty space. This may be due to the sheer scale of mass transport, but it also arises from a system of active and non-active zones located throughout contemporary terminals. This photo series emphasises the "emptiness" of these overlooked left-over spaces that result from demands of circulation and construction.1. We Move the WorldTo many travellers, airport gate lounges and their surrounding facilities are loaded with a variety of contradictory associations and affects. Their open warehouse banality and hard industrial sterility tune our bodies to the vast technical and commercial systems that are imbricated through almost every aspect of contemporary everyday life.Here at the departure gate the traveller's body comes to a moment's rest. They are granted a short respite from the anxious routines of check in, body scans, security, information processing, passport scanning, itineraries, boarding procedures and wayfaring the terminal. The landside processing system deposits them at this penultimate point before final propulsion into the invisible airways that pipe them into their destination. We hear the broadcasting of boarding times, check-in times, name's of people that break them away from stillness, forcing people to move, to re-arrange themselves, or to hurry up. Along the way the passenger encounters a variety of techno-spatial experiences that sit at odds with the overriding discourse of velocity, speed and efficiency that lie at the centre of our social understanding of air travel. The airline's phantasmagorical projections of itself as guarantor and enabler of mass mobilities coincides uncomfortably with the passenger's own wish-fulfilment of escape and freedom.In this we can agree with the designer Bruce Mau when he suggests that these projection systems, comprised of "openings of every sort — in schedules, in urban space, on clothes, in events, on objects, in sightlines — are all inscribed with the logic of the market” (Mau 7). The advertising slogans and images everywhere communicate the dual concept that the aviation industry can deliver the world to us on time while simultaneously porting us to any part of the world still willing to accept Diners, VISA or American Express. At each point along the way these openings exhort us to stop, to wait in line, to sit still or to be patient. The weird geographies depicted by the light boxes appear like interpenetrating holes in space and time. These travel portals are strangely still, and only activated by the impending promise of movement.Be still and relax. Your destination is on its way. 2. Attentive AttentionAlongside the panoramic widescreen windows that frame the choreography of the tarmac and flight paths outside, appear luminous advertising light boxes. Snapped tightly to grid and locked into strategic sightlines and thoroughfares, these wall pieces are filled with a rotating menu of contemporary airport haiku and ersatz Swiss graphic design.Mechanically conditioned air pumped out of massive tubes creates the atmosphere for a very particular amalgam of daylight, tungsten, and fluorescent light waves. Low-oxygen-emitting indoor plants are no match for the diesel-powered plant rooms that maintain the constant flow of air to every nook and cranny of this massive processing machine. As Rem Koolhaas puts it, "air conditioning has launched the endless building. If architecture separates buildings, air conditioning unites them" (Koolhaas). In Koolhaas's lingo, these are complex "junkspaces" unifying, colliding and coalescing a number of different circulatory systems, temporalities and mobilities.Gillian Fuller reminds us there is a lot of stopping and going and stopping in the global circulatory system typified by air-terminal-space.From the packing of clothes in fixed containers to strapping your belt – tight and low – stillness and all its requisite activities, technologies and behaviours are fundamental to the ‘flow’ architectures that organize the motion of the globalizing multitudes of today (Fuller, "Store" 63). It is precisely this functional stillness organised around the protocols of store and forward that typifies digital systems, the packet switching of network cultures and the junkspace of airports alike.In these zones of transparency where everything is on view, the illuminated windows so proudly brought to us by J C Decaux flash forward to some idealized moment in the future. In this anticipatory moment, the passenger's every fantasy of in-flight service is attended to. The ultimate in attentiveness (think dimmed lights, soft pillows and comfy blankets), this still image is captured from an improbable future suspended behind the plywood and steel seating available in the moment —more reminiscent of park benches in public parks than the silver-service imagined for the discerning traveller.3. We Know ChicagoSelf-motion is itself a demonstration against the earth-binding weight of gravity. If we climb or fly, our defiance is greater (Appleyard 180).The commercial universe of phones, cameras, computer network software, financial instruments, and an array of fancy new gadgets floating in the middle of semi-forgotten transit spaces constitutes a singular interconnected commercial organism. The immense singularity of these claims to knowledge and power loom solemnly before us asserting their rights in the Esperanto of "exclusive rollover minutes", "nationwide long distance", "no roaming charges" and insider local knowledge. The connective tissue that joins one part of the terminal to a commercial centre in downtown Chicago is peeled away, revealing techno-veins and tendrils reaching to the sky. It's a graphic view that offers none of the spectacular openness and flights of fancy associated with the transit lounges located on the departure piers and satellites. Along these circulatory ribbons we experience the still photography and the designer's arrangement of type to attract the eye and lure the body. The blobby diagonals of the telco's logo blend seamlessly with the skyscraper's ribbons of steel, structural exoskeleton and wireless telecommunication cloud.In this plastinated anatomy, the various layers of commercially available techno-space stretch out before the traveller. Here we have no access to the two-way vistas made possible by the gigantic transparent tube structures of the contemporary air terminal. Waiting within the less travelled zones of the circulatory system we find ourselves suspended within the animating system itself. In these arteries and capillaries the flow is spread out and comes close to a halt in the figure of the graphic logo. We know Chicago is connected to us.In the digital logic of packet switching and network effects, there is no reason to privilege the go over the stop, the moving over the waiting. These light box portals do not mirror our bodies, almost at a complete standstill now. Instead they echo the commercial product world that they seek to transfuse us into. What emerges is a new kind of relational aesthetics that speaks to the complex corporeal, temporal, and architectural dimensions of stillness and movement in transit zones: like "a game, whose forms, patterns and functions develop and evolve according to periods and social contexts” (Bourriaud 11). 4. Machine in the CaféIs there a possible line of investigation suggested by the fact that sound waves become visible on the fuselage of jet planes just before they break the sound barrier? Does this suggest that the various human senses are translatable one into the other at various intensities (McLuhan 180)?Here, the technological imaginary contrasts itself with the techno alfresco dining area enclosed safely behind plate glass. Inside the cafes and bars, the best businesses in the world roll out their biggest guns to demonstrate the power, speed and scale of their network coverage (Remmele). The glass windows and light boxes "have the power to arrest a crowd around a commodity, corralling them in chic bars overlooking the runway as they wait for their call, but also guiding them where to go next" (Fuller, "Welcome" 164). The big bulbous plane sits plump in its hangar — no sound barriers broken here. It reassures us that our vehicle is somewhere there in the network, resting at its STOP before its GO. Peeking through the glass wall and sharing a meal with us, this interpenetrative transparency simultaneously joins and separates two planar dimensions — machinic perfection on one hand, organic growth and death on the other (Rowe and Slutsky; Fuller, "Welcome").Bruce Mau is typical in suggesting that the commanding problem of the twentieth century was speed, represented by the infamous image of a US Navy Hornet fighter breaking the sound barrier in a puff of smoke and cloud. It has worked its way into every aspect of the design experience, manufacturing, computation and transport.But speed masks more than it reveals. The most pressing problem facing designers and citizens alike is growth — from the unsustainable logic of infinite growth in GDP to the relentless application of Moore's Law to the digital networks and devices that define contemporary society in the first world. The shift of emphasis from speed to growth as a time-based event with breaking points and moments of rupture has generated new possibilities. "Growth is nonlinear and unpredictable ... Few of us are ready to admit that growth is constantly shadowed by its constitutive opposite, that is equal partners with death” (Mau 497).If speed in part represents a flight from death (Virilio), growth invokes its biological necessity. In his classic study of the persistence of the pastoral imagination in technological America, The Machine in the Garden, Leo Marx charted the urge to idealize rural environments at the advent of an urban industrialised America. The very idea of "the flight from the city" can be understood as a response to the onslaught of technological society and it's deathly shadow. Against the murderous capacity of technological society stood the pastoral ideal, "incorporated in a powerful metaphor of contradiction — a way of ordering meaning and value that clarifies our situation today" (Marx 4). 5. Windows at 35,000 FeetIf waiting and stillness are active forms of bodily engagement, we need to consider the different layers of motion and anticipation embedded in the apprehension of these luminous black-box windows. In The Virtual Window, Anne Friedberg notes that the Old Norse derivation of the word window “emphasizes the etymological root of the eye, open to the wind. The window aperture provides ventilation for the eye” (103).The virtual windows we are considering here evoke notions of view and shelter, open air and sealed protection, both separation from and connection to the outside. These windows to nowhere allow two distinct visual/spatial dimensions to interface, immediately making the visual field more complex and fragmented. Always simultaneously operating on at least two distinct fields, windows-within-windows provide a specialized mode of spatial and temporal navigation. As Gyorgy Kepes suggested in the 1940s, the transparency of windows "implies more than an optical characteristic; it implies a broader spatial order. Transparency means a simultaneous perception of different spatial locations" (Kepes 77).The first windows in the world were openings in walls, without glass and designed to allow air and light to fill the architectural structure. Shutters were fitted to control air flow, moderate light and to enclose the space completely. It was not until the emergence of glass technologies (especially in Holland, home of plate glass for the display of commercial products) that shielding and protection also allowed for unhindered views (by way of transparent glass). This gives rise to the thesis that windows are part of a longstanding architectural/technological system that moderates the dual functions of transparency and separation. With windows, multi-dimensional planes and temporalities can exist in the same time and space — hence a singular point of experience is layered with many other dimensions. Transparency and luminosity "ceases to be that which is perfectly clear and becomes instead that which is clearly ambiguous" (Rowe and Slutsky 45). The light box air-portals necessitate a constant fluctuation and remediation that is at once multi-planar, transparent and "hard to read". They are informatic.From holes in the wall to power lunch at 35,000 feet, windows shape the manner in which light, information, sights, smells, temperature and so on are modulated in society. "By allowing the outside in and the inside out, [they] enable cosmos and construction to innocently, transparently, converge" (Fuller, "Welcome" 163). Laptop, phone, PDA and light box point to the differential mobilities within a matrix that traverses multiple modes of transparency and separation, rest and flight, stillness and speed.6. Can You Feel It?Increasingly the whole world has come to smell alike: gasoline, detergents, plumbing, and junk foods coalesce into the catholic smog of our age (Illich 47).In these forlorn corners of mobile consumption, the dynamic of circulation simultaneously slows and opens out. The surfaces of inscription implore us to see them at precisely the moment we feel unseen, unguided and off-camera. Can you see it, can you feel it, can you imagine the unimaginable, all available to us on demand? Expectation and anticipation give us something to look forward to, but we're not sure we want what's on offer.Air travel radicalizes the separation of the air traveller from ground at one instance and from the atmosphere at another. Air, light, temperature and smell are all screened out or technologically created by the terminal plant and infrastructure. The closer the traveller moves towards stillness, the greater the engagement with senses that may have been ignored by the primacy of the visual in so much of this circulatory space. Smell, hunger, tiredness, cold and hardness cannot be screened out.In this sense, the airplanes we board are terminal extensions, flying air-conditioned towers or groundscrapers jet-propelled into highways of the air. Floating above the horizon, immersed in a set of logistically ordained trajectories and pressurized bubbles, we look out the window and don't see much at all. Whatever we do see, it's probably on the screen in front of us which disconnects us from one space-time-velocity at the same time that it plugs us into another set of relations. As Koolhaas says, junkspace is "held together not by structure, but by skin, like a bubble" (Koolhaas). In these distended bubbles, the traveler momentarily occupies an uncommon transit space where stillness is privileged and velocity is minimized. The traveler's body itself is "engaged in and enacting a whole kaleidoscope of different everyday practices and forms" during the course of this less-harried navigation (Bissell 282).7. Elevator MusicsThe imaginary wheel of the kaleidoscope spins to reveal a waiting body-double occupying the projected territory of what appears to be a fashionable Miami. She's just beyond our reach, but beside her lies a portal to another dimension of the terminal's vascular system.Elevators and the networks of shafts and vents that house them, are to our buildings like veins and arteries to the body — conduits that permeate and structure the spaces of our lives while still remaining separate from the fixity of the happenings around them (Garfinkel 175). The terminal space contains a number of apparent cul-de-sacs and escape routes. Though there's no background music piped in here, another soundtrack can be heard. The Muzak corporation may douse the interior of the elevator with its own proprietary aural cologne, but at this juncture the soundscape is more "open". This functional shifting of sound from figure to ground encourages peripheral hearing, providing "an illusion of distended time", sonically separated from the continuous hum of "generators, ventilation systems and low-frequency electrical lighting" (Lanza 43).There is another dimension to this acoustic realm: “The mobile ecouteur contracts the flows of information that are supposed to keep bodies usefully and efficiently moving around ... and that turn them into functions of information flows — the speedy courier, the networking executive on a mobile phone, the scanning eyes of the consumer” (Munster 18).An elevator is a grave says an old inspector's maxim, and according to others, a mechanism to cross from one world to another. Even the quintessential near death experience with its movement down a long illuminated tunnel, Garfinkel reminds us, “is not unlike the sensation of movement we experience, or imagine, in a long swift elevator ride” (Garfinkel 191).8. States of SuspensionThe suspended figure on the screen occupies an impossible pose in an impossible space: half falling, half resting, an anti-angel for today's weary air traveller. But it's the same impossible space revealed by the airport and bundled up in the experience of flight. After all, the dimension this figures exists in — witness the amount of activity in his suspension — is almost like a black hole with the surrounding universe collapsing into it. The figure is crammed into the light box uncomfortably like passengers in the plane, and yet occupies a position that does not exist in the Cartesian universe.We return to the glossy language of advertising, its promise of the external world of places and products delivered to us by the image and the network of travel. (Remmele) Here we can go beyond Virilio's vanishing point, that radical reversibility where inside and outside coincide. Since everybody has already reached their destination, for Virilio it has become completely pointless to leave: "the inertia that undermines your corporeity also undermines the GLOBAL and the LOCAL; but also, just as much, the MOBILE and the IMMOBILE” (Virilio 123; emphasis in original).In this clinical corner of stainless steel, glass bricks and exit signs hangs an animated suspension that articulates the convergence of a multitude of differentials in one image. 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