WorldWideScience

Sample records for dynamic airline scheduling

  1. Dynamic Airline Scheduling: An Analysis of the Potentials of Refleeting and Retiming

    DEFF Research Database (Denmark)

    Warburg, Valdemar; Hansen, Troels G.; Larsen, Allan

    2008-01-01

    We present a Dynamic Airline Scheduling (DAS) technique which is able to change departure times and reassign aircraft types during the booking process to meet fluctuating passenger demands. The procedure is tested on several different days before departure, resulting in a significant profit...... increase for a major European airline. The results also indicate that applying DAS close to departure yields the largest potential....

  2. Dynamic Airline Scheduling: An Analysis of the Potentials of Refleeting and Retiming

    DEFF Research Database (Denmark)

    Warburg, Valdemar; Hansen, Troels G.; Larsen, Allan

    We present a Dynamic Airline Scheduling (DAS) technique which is able to change departure times and reassign aircraft types during the booking process to meet fluctuating passenger demands. The procedure is tested on several different days before departure, resulting in a significant profit...... increase for a major European airline. The results also indicate that applying DAS close to departure yields the largest potential....

  3. Planning and Scheduling of Airline Operations

    Directory of Open Access Journals (Sweden)

    İlkay ORHAN

    2010-02-01

    Full Text Available The Turkish Civil Aviation sector has grown at a rate of 53 % between the years 2002-2008 owing to countrywide economical developments and some removed restrictions in the aviation field. Successful international companies in the sector use advanced computer-supported solution methods for their planning and scheduling problems. These methods have been providing significant competitive advantages to those companies. There are four major scheduling and planning problems in the airline sector: flight scheduling, aircraft scheduling, crew scheduling and disruptions management. These aforementioned scheduling and planning problems faced by all airline companies in the airline sector were examined in detail. Studies reveal that companies using the advanced methods might gain significant cost reductions. However, even then, the time required for solving large scale problems may not satisfy the decision quality desired by decision makers. In such cases, using modern decision methods integrated with advanced technologies offer companies an opportunity for significant cost-advantages.

  4. Solving a manpower scheduling problem for airline catering using metaheuristics

    DEFF Research Database (Denmark)

    Ho, Sin C.; Leung, Janny M. Y.

    2010-01-01

    We study a manpower scheduling problem with job time-windows and job-skills compatibility constraints. This problem is motivated by airline catering operations, whereby airline meals and other supplies are delivered to aircrafts on the tarmac just before the flights take-off.  Jobs (flights) must...

  5. Dynamic Oligopoly Pricing: Evidence from the Airline Industry

    OpenAIRE

    Siegert, Caspar; Ulbricht, Robert

    2014-01-01

    We explore how pricing dynamics in the European airline industry vary with the competitive environment. Our results highlight substantial variations in pricing dynamics that are consistent with a theory of intertemporal price discrimination. First, the rate at which prices increase towards the scheduled travel date is decreasing in competition, supporting the idea that competition restrains the ability of airlines to price-discriminate. Second, the sensitivity to competition is substantially ...

  6. Solving a manpower scheduling problem for airline catering using tabu search

    DEFF Research Database (Denmark)

    Ho, Sin C.; Leung, Janny M. Y.

    We study a manpower scheduling problem with job time-windows and job-skills compatibility constraints. This problem is motivated by airline catering operations, whereby airline meals and other supplies are delivered to aircrafts on the tarmac just before the flights take off. Jobs (flights) must...

  7. Estimation of Airline Benefits from Avionics Upgrade under Preferential Merge Re-sequence Scheduling

    Science.gov (United States)

    Kotegawa, Tatsuya; Cayabyab, Charlene Anne; Almog, Noam

    2013-01-01

    Modernization of the airline fleet avionics is essential to fully enable future technologies and procedures for increasing national airspace system capacity. However in the current national airspace system, system-wide benefits gained by avionics upgrade are not fully directed to aircraft/airlines that upgrade, resulting in slow fleet modernization rate. Preferential merge re-sequence scheduling is a best-equipped-best-served concept designed to incentivize avionics upgrade among airlines by allowing aircraft with new avionics (high-equipped) to be re-sequenced ahead of aircraft without the upgrades (low-equipped) at enroute merge waypoints. The goal of this study is to investigate the potential benefits gained or lost by airlines under a high or low-equipped fleet scenario if preferential merge resequence scheduling is implemented.

  8. A study of the financial history of the U. S. scheduled airlines and the improvement of airline profitability through technology

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, D.E.

    1975-07-01

    The financial history of the U.S. scheduled airline industry was investigated to determine the causes of the erratic profit performance of the industry and to evaluate potential economic gains from technology advances of recent years. Operational and economic factors affecting past and future profitability of the industry are discussed, although no attempt was made to examine the profitability of individual carriers. The results of the study indicate that the profit erosion of the late 1960's and early 1970's was due more to excess capacity than to inadequate fare levels, but airline problems were severely compounded by the rapid fuel price escalation in 1974 and 1975. Near-term solutions to the airline financial problems depend upon the course of action by the industry and the CAB and the general economic health of the nation. For the longer term, the only acceptable alternative to continued fare increases is a reduction in unit operating costs through technological advance. The next generation of transports is expected to incorporate technologies developed under Government sponsorship in the 1960's and 1970's with significant improvements in fuel consumption and operating costs. (GRA)

  9. A duty-period-based formulation of the airline crew scheduling problem

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, K.

    1994-12-31

    We present a new formulation of the airline crew scheduling problem that explicitly considers the duty periods. We suggest an algorithm for solving the formulation by a column generation approach with branch-and-bound. Computational results are reported for a number of test problems.

  10. Cascading Delay Risk of Airline Workforce Deployments with Crew Pairing and Schedule Optimization.

    Science.gov (United States)

    Chung, Sai Ho; Ma, Hoi Lam; Chan, Hing Kai

    2017-08-01

    This article concerns the assignment of buffer time between two connected flights and the number of reserve crews in crew pairing to mitigate flight disruption due to flight arrival delay. Insufficient crew members for a flight will lead to flight disruptions such as delays or cancellations. In reality, most of these disruption cases are due to arrival delays of the previous flights. To tackle this problem, many research studies have examined the assignment method based on the historical flight arrival delay data of the concerned flights. However, flight arrival delays can be triggered by numerous factors. Accordingly, this article proposes a new forecasting approach using a cascade neural network, which considers a massive amount of historical flight arrival and departure data. The approach also incorporates learning ability so that unknown relationships behind the data can be revealed. Based on the expected flight arrival delay, the buffer time can be determined and a new dynamic reserve crew strategy can then be used to determine the required number of reserve crews. Numerical experiments are carried out based on one year of flight data obtained from 112 airports around the world. The results demonstrate that by predicting the flight departure delay as the input for the prediction of the flight arrival delay, the prediction accuracy can be increased. Moreover, by using the new dynamic reserve crew strategy, the total crew cost can be reduced. This significantly benefits airlines in flight schedule stability and cost saving in the current big data era. © 2016 Society for Risk Analysis.

  11. 41 CFR 301-10.117 - May I keep compensation an airline gives me for voluntarily vacating my seat on my scheduled...

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false May I keep compensation an airline gives me for voluntarily vacating my seat on my scheduled airline flight when the airline asks for volunteers? 301-10.117 Section 301-10.117 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY)...

  12. Optimizing Air Transportation Service to Metroplex Airports. Par 2; Analysis Using the Airline Schedule Optimization Model (ASOM)

    Science.gov (United States)

    Donoue, George; Hoffman, Karla; Sherry, Lance; Ferguson, John; Kara, Abdul Qadar

    2010-01-01

    The air transportation system is a significant driver of the U.S. economy, providing safe, affordable, and rapid transportation. During the past three decades airspace and airport capacity has not grown in step with demand for air transportation; the failure to increase capacity at the same rate as the growth in demand results in unreliable service and systemic delay. This report describes the results of an analysis of airline strategic decision-making that affects geographic access, economic access, and airline finances, extending the analysis of these factors using historic data (from Part 1 of the report). The Airline Schedule Optimization Model (ASOM) was used to evaluate how exogenous factors (passenger demand, airline operating costs, and airport capacity limits) affect geographic access (markets-served, scheduled flights, aircraft size), economic access (airfares), airline finances (profit), and air transportation efficiency (aircraft size). This analysis captures the impact of the implementation of airport capacity limits, as well as the effect of increased hedged fuel prices, which serve as a proxy for increased costs per flight that might occur if auctions or congestion pricing are imposed; also incorporated are demand elasticity curves based on historical data that provide information about how passenger demand is affected by airfare changes.

  13. Adaptation strategies of airline travel agencies to the dynamics of ...

    African Journals Online (AJOL)

    The role of airline travel agencies in a changing operational environment depends on their ability to adapt and survive in the airline travel industry. This paper examines the adaptation strategies airline travel agencies adopt to remain in business. Data for this paper was obtained through multi-stage sampling system that ...

  14. A study of the financial history of the U.S. scheduled airlines and the improvement of airline profitability through technology

    Science.gov (United States)

    Wilcox, D. E.

    1975-01-01

    The financial history of the U.S. scheduled airline industry was investigated to determine the causes of the erratic profit performance of the industry and to evaluate potential economic gains from technology advances of recent years. Operational and economic factors affecting past and future profitability of the industry are discussed, although no attempt was made to examine the profitability of individual carriers. The results of the study indicate that the profit erosion of the late 1960's and early 1970's was due more to excess capacity than to inadequate fare levels, but airline problems were severely compounded by the rapid fuel price escalation in 1974 and 1975. Near-term solutions to the airline financial problems depend upon the course of action by the industry and the CAB and the general economic health of the nation. For the longer term, the only acceptable alternative to continued fare increases is a reduction in unit operating costs through technological advance. The next generation of transports is expected to incorporate technologies developed under Government sponsorship in the 1960's and 1970's with significant improvements in fuel consumption and operating costs.

  15. Evaluating energy efficiency for airlines: An application of Virtual Frontier Dynamic Slacks Based Measure

    International Nuclear Information System (INIS)

    Cui, Qiang; Li, Ye; Yu, Chen-lu; Wei, Yi-Ming

    2016-01-01

    The fast growing Revenue Passenger Kilometers and the relatively lagged energy supply of aviation industry impels the airlines to improve energy efficiency. In this paper, we focus on evaluating and analyzing influencing factors for airline energy efficiency. Number of employees and aviation kerosene are chosen as the inputs. Revenue Ton Kilometers, Revenue Passenger Kilometers and total business income are the outputs. Capital stock is selected as the dynamic factor. A new model, Virtual Frontier Dynamic Slacks Based Measure, is proposed to calculate the energy efficiencies of 21 airlines from 2008 to 2012. We verify two important properties to manifest the advantages of the new model. Then a regression is run to analyze the influencing factors of airline energy efficiency. The main findings are: 1. The overall energy efficiency of Malaysia Airlines is the highest during 2008–2012.2. Per capita Gross Domestic Product, the average service age of fleet size and average haul distance have significant impacts on the efficiency score. 3. The difference between full-service carriers and low-cost carriers has no significant effects on airline energy efficiency. - Highlights: • A Virtual Frontier Dynamic Slacks Based Measure is developed. • 21 airlines' energy efficiencies are evaluated. • Malaysia Airlines has the highest overall energy efficiency. • Three explanatory variables have significant impacts.

  16. Metroplex Optimization Model Expansion and Analysis: The Airline Fleet, Route, and Schedule Optimization Model (AFRS-OM)

    Science.gov (United States)

    Sherry, Lance; Ferguson, John; Hoffman, Karla; Donohue, George; Beradino, Frank

    2012-01-01

    This report describes the Airline Fleet, Route, and Schedule Optimization Model (AFRS-OM) that is designed to provide insights into airline decision-making with regards to markets served, schedule of flights on these markets, the type of aircraft assigned to each scheduled flight, load factors, airfares, and airline profits. The main inputs to the model are hedged fuel prices, airport capacity limits, and candidate markets. Embedded in the model are aircraft performance and associated cost factors, and willingness-to-pay (i.e. demand vs. airfare curves). Case studies demonstrate the application of the model for analysis of the effects of increased capacity and changes in operating costs (e.g. fuel prices). Although there are differences between airports (due to differences in the magnitude of travel demand and sensitivity to airfare), the system is more sensitive to changes in fuel prices than capacity. Further, the benefits of modernization in the form of increased capacity could be undermined by increases in hedged fuel prices

  17. adaptation strategies of airline travel agencies to the dynamics of ...

    African Journals Online (AJOL)

    Bawa et al.

    strategies airline travel agencies adopt to remain in business. Data for this paper was ... that in 2013, travel and tourism's total contribution to the global economy rose to ... reality of today's tourism industry as it has penetrated the decision.

  18. AIRLINE ITINERARY CHOICE IN A DYNAMIC SUPPLY ENVIRONMENT: RESULTS FROM A STATED PREFERENCE SURVEY

    Directory of Open Access Journals (Sweden)

    Uzi Freund-Feinstei

    2017-12-01

    Full Text Available This paper investigates the choice of airline itineraries in dynamic settings using a tailored stated preference survey. The paper hypothesizes that airline itinerary choice is not a one-time event, but a continuous process during a certain time frame. Consumers can choose either to purchase an itinerary, deferring choice up to the end of the sales period, or completely declining the purchase. Understanding such consumers’ behavior is specifically relevant to the tourism industry, where firms are extensively utilizing internet websites to offer their products (e.g., airline tickets, hotel rooms to consumers. The paper describes the stated preference survey with real itineraries of various airlines on medium and long-haul routes. Choice sets are composed with dynamic and static variables and socio-economic variables. Questionnaires were distributed electronically among various groups of respondents, yielding a sample of 914 persons. Results show that (i itinerary choice deferring takes place, with differences between tourists and business-travelers, (ii the decision whether to defer choice is affected by dynamically changing variables and by the length of each respondent’s allocated choice period, and (iii the proposed methodology is adequate for investigating choice in dynamic settings and thus indicating its potential for further research in transportation planning and in tourism.

  19. Airlines' strategic interactions and airport pricing in a dynamic bottleneck model of congestion

    NARCIS (Netherlands)

    Silva Montalva, H.E.; Verhoef, E.T.; van den Berg, V.A.C.

    2014-01-01

    This paper analyzes efficient pricing at a congested airport dominated by a single firm. Unlike much of the previous literature, we combine a dynamic bottleneck model of congestion and a vertical structure model that explicitly considers the role of airlines and passengers. We show that a

  20. A dynamic approach to vehicle scheduling

    NARCIS (Netherlands)

    D. Huisman (Dennis); R. Freling (Richard); A.P.M. Wagelmans (Albert)

    2001-01-01

    textabstractThis paper presents a dynamic approach to the vehicle scheduling problem. We discuss the potential benefit of our approach compared to the traditional one, where the vehicle scheduling problem is solved only once for a whole period and the travel times are assumed to be fixed. In our

  1. Dynamic Pricing for Airline Revenue Management under Passenger Mental Accounting

    Directory of Open Access Journals (Sweden)

    Yusheng Hu

    2015-01-01

    Full Text Available Mental accounting is a far-reaching concept, which is often used to explain various kinds of irrational behaviors in human decision making process. This paper investigates dynamic pricing problems for single-flight and multiple flights settings, respectively, where passengers may be affected by mental accounting. We analyze dynamic pricing problems by means of the dynamic programming method and obtain the optimal pricing strategies. Further, we analytically show that the passenger mental accounting depth has a positive effect on the flight’s expected revenue for the single flight and numerically illustrate that the passenger mental accounting depth has a positive effect on the optimal prices for the multiple flights.

  2. Project management with dynamic scheduling baseline scheduling, risk analysis and project control

    CERN Document Server

    Vanhoucke, Mario

    2013-01-01

    The topic of this book is known as dynamic scheduling, and is used to refer to three dimensions of project management and scheduling: the construction of a baseline schedule and the analysis of a project schedule's risk as preparation of the project control phase during project progress. This dynamic scheduling point of view implicitly assumes that the usability of a project's baseline schedule is rather limited and only acts as a point of reference in the project life cycle.

  3. Optimization in the airline industry

    Energy Technology Data Exchange (ETDEWEB)

    Barnhart, C.

    1994-12-31

    In this paper, we discuss applications of operations research techniques in the airline industry. Specifically, we present models and solution procedures for crew scheduling, fleet assignment and service design. The crew scheduling problem involves the assignment of crews to scheduled flights, and the fleet assignment problem involves the assignment of aircraft to flights. Service design requires the determination of both the flight schedule and the fleet assignment. We summarize our computational experiences in solving various problems for large domestic and international airlines.

  4. Robust Airline Schedules

    OpenAIRE

    Eggenberg, Niklaus; Salani, Matteo; Bierlaire, Michel

    2010-01-01

    Due to economic pressure industries, when planning, tend to focus on optimizing the expected profit or the yield. The consequence of highly optimized solutions is an increased sensitivity to uncertainty. This generates additional "operational" costs, incurred by possible modifications of the original plan to be performed when reality does not reflect what was expected in the planning phase. The modern research trend focuses on "robustness" of solutions instead of yield or profit. Although ro...

  5. Runway Scheduling Using Generalized Dynamic Programming

    Science.gov (United States)

    Montoya, Justin; Wood, Zachary; Rathinam, Sivakumar

    2011-01-01

    A generalized dynamic programming method for finding a set of pareto optimal solutions for a runway scheduling problem is introduced. The algorithm generates a set of runway fight sequences that are optimal for both runway throughput and delay. Realistic time-based operational constraints are considered, including miles-in-trail separation, runway crossings, and wake vortex separation. The authors also model divergent runway takeoff operations to allow for reduced wake vortex separation. A modeled Dallas/Fort Worth International airport and three baseline heuristics are used to illustrate preliminary benefits of using the generalized dynamic programming method. Simulated traffic levels ranged from 10 aircraft to 30 aircraft with each test case spanning 15 minutes. The optimal solution shows a 40-70 percent decrease in the expected delay per aircraft over the baseline schedulers. Computational results suggest that the algorithm is promising for real-time application with an average computation time of 4.5 seconds. For even faster computation times, two heuristics are developed. As compared to the optimal, the heuristics are within 5% of the expected delay per aircraft and 1% of the expected number of runway operations per hour ad can be 100x faster.

  6. Airline Passengers

    OpenAIRE

    Wittmer, Andreas; Hinnen, Gieri

    2016-01-01

    Airlines create value for employees, investors, governments, customers and consumers. This chapter focuses on the customers and consumers of the airline product. Airline customers, who include passengers and corporate travel providers, exert considerable market power in the air transport industry through their purchasing decisions and travel behaviour. As a purchaser of a commercial aviation product, customers are responsible for stimulating product and service innovation and their behaviour ...

  7. Interactive Dynamic Mission Scheduling for ASCA

    Science.gov (United States)

    Antunes, A.; Nagase, F.; Isobe, T.

    The Japanese X-ray astronomy satellite ASCA (Advanced Satellite for Cosmology and Astrophysics) mission requires scheduling for each 6-month observation phase, further broken down into weekly schedules at a few minutes resolution. Two tools, SPIKE and NEEDLE, written in Lisp and C, use artificial intelligence (AI) techniques combined with a graphic user interface for fast creation and alteration of mission schedules. These programs consider viewing and satellite attitude constraints as well as observer-requested criteria and present an optimized set of solutions for review by the planner. Six-month schedules at 1 day resolution are created for an oversubscribed set of targets by the SPIKE software, originally written for HST and presently being adapted for EUVE, XTE and AXAF. The NEEDLE code creates weekly schedules at 1 min resolution using in-house orbital routines and creates output for processing by the command generation software. Schedule creation on both the long- and short-term scale is rapid, less than 1 day for long-term, and one hour for short-term.

  8. Dynamic Scheduling for Cloud Reliability using Transportation Problem

    OpenAIRE

    P. Balasubramanie; S. K. Senthil Kumar

    2012-01-01

    Problem statement: Cloud is purely a dynamic environment and the existing task scheduling algorithms are mostly static and considered various parameters like time, cost, make span, speed, scalability, throughput, resource utilization, scheduling success rate and so on. Available scheduling algorithms are mostly heuristic in nature and more complex, time consuming and does not consider reliability and availability of the cloud computing environment. Therefore there is a need to implement a sch...

  9. Airline Disruption Management - Perspectives, Experiences and Outlook

    DEFF Research Database (Denmark)

    Kohl, Niklas; Larsen, Allan; Larsen, Jesper

    2004-01-01

    Over the past decade, airlines have become more concerned with developing an optimal flight schedule, with very little slack left to accommodate for any form of variation from the optimal solution. During operation the planned schedules often have to be revised due to disruptions caused...... report on experiences from a large research and development project on airline disruption management. Within the project the first prototype of a multiple resource decision support system at the operations control center in a major airline, has been implemented....... by for example severe weather, technical problems and crew sickness. Thus, the field of Airline Disruption Management has emerged within the past few years. The increased focus on cutting cost at the major airlines has intensified the interest in the development of new and cost e cient methods to handle airline...

  10. Distributed continuous energy scheduling for dynamic virtual power plants

    International Nuclear Information System (INIS)

    Niesse, Astrid

    2015-01-01

    This thesis presents DynaSCOPE as distributed control method for continuous energy scheduling for dynamic virtual power plants (DVPP). DVPPs aggregate the flexibility of distributed energy units to address current energy markets. As an extension of the Virtual Power Plant concept they show high dynamics in aggregation and operation of energy units. Whereas operation schedules are set up for all energy units in a day-ahead planning procedure, incidents may render these schedules infeasible during execution, like deviation from prognoses or outages. Thus, a continuous scheduling process is needed to ensure product fulfillment. With DynaSCOPE, software agents representing single energy units solve this problem in a completely distributed heuristic approach. Using a stepped concept, several damping mechanisms are applied to allow minimum disturbance while continuously trying to fulfill the product as contracted at the market.

  11. Airline Disruption Management - Perspectives, Experiences and Outlook

    DEFF Research Database (Denmark)

    Kohl, Niklas; Larsen, Allan; Larsen, Jesper

    2007-01-01

    Over the past decade, airlines have become more concerned with developing an optimal flight schedule, with very little slack left to accommodate for any form of variation from the optimal solution. During operation the planned schedules often have to be revised due to disruptions caused...... part we report on experiences from a large research and development project on airline disruption management. Within the project the first prototype of a multiple resource decision support system at the operations control center in a major airline, has been implemented....... by for example severe weather, technical problems and crew sickness. Thus, the field of Airline Disruption Management has emerged within the past few years. The increased focus on cutting cost at the major airlines has intensified the interest in the development of new and cost efficient methods to handle...

  12. An optimal dynamic interval preventive maintenance scheduling for series systems

    International Nuclear Information System (INIS)

    Gao, Yicong; Feng, Yixiong; Zhang, Zixian; Tan, Jianrong

    2015-01-01

    This paper studies preventive maintenance (PM) with dynamic interval for a multi-component system. Instead of equal interval, the time of PM period in the proposed dynamic interval model is not a fixed constant, which varies from interval-down to interval-up. It is helpful to reduce the outage loss on frequent repair parts and avoid lack of maintenance of the equipment by controlling the equipment maintenance frequency, when compared to a periodic PM scheme. According to the definition of dynamic interval, the reliability of system is analyzed from the failure mechanisms of its components and the different effects of non-periodic PM actions on the reliability of the components. Following the proposed model of reliability, a novel framework for solving the non-periodical PM schedule with dynamic interval based on the multi-objective genetic algorithm is proposed. The framework denotes the strategies include updating strategy, deleting strategy, inserting strategy and moving strategy, which is set to correct the invalid population individuals of the algorithm. The values of the dynamic interval and the selections of PM action for the components on every PM stage are determined by achieving a certain level of system availability with the minimum total PM-related cost. Finally, a typical rotary table system of NC machine tool is used as an example to describe the proposed method. - Highlights: • A non-periodic preventive maintenance scheduling model is proposed. • A framework for solving the non-periodical PM schedule problem is developed. • The interval of non-periodic PM is flexible and schedule can be better adjusted. • Dynamic interval leads to more efficient solutions than fixed interval does

  13. An insight into airline dynamic pricing practices in emerging markets: Effects of low cost carriers' presence on routes from Belgrade 'Nikola Tesla' airport

    Directory of Open Access Journals (Sweden)

    Ivanov Nikola V.

    2016-01-01

    Full Text Available Dynamic pricing and revenue management in airline industry have been the subject of research for more than twenty years now. Building upon that massive body of research, in this paper we investigate actual dynamic pricing patterns in new and emerging markets. We specifically focus on the impact that recent entry of low cost carriers on a number of routes from Belgrade Nikola Tesla Airport might have had on pricing practices of legacy incumbents. Unlike with most of previous contributions in the field, we analyse the market characterised by relatively low frequencies and predominantly short-to-medium haul flights. In this paper, we observe and analyse pricing dynamics on two types of routes: routes where only legacy carriers operate and routes where legacy carriers face competition from low cost carriers. The effects of route competition on offered airline fares are estimated and conclusions derived.

  14. Airline Quality Rating 2003

    OpenAIRE

    Bowen, Brent D.; Headley, Dean E.

    2003-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, the Airline Quality Rating 2003, reflects monthly Airline Quality Rating scores for 2002. AQR scores for the calendar year 2002 are based on 15 elements that focus on airline performance areas important to air travel consumers. The Airline Quality Rating 2003 is a summary of month-by-month qualit...

  15. Airline Quality Rating 2013

    OpenAIRE

    Bowen, Brent D.; Headley, Dean E.

    2013-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method for assessing airline quality on combined multiple performance criteria. This current report, the Airline Quality Rating 2013, reflects monthly Airline Quality Rating scores for calendar year 2012. AQR scores for 2013 are based on 15 elements in four major areas that focus on airline performance aspects important to air travel consumers over the calendar year of 2012. The Airline Quality...

  16. Airline Quality Rating 2001

    OpenAIRE

    Bowen, Brent D.; Headley, Dean E.

    2001-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, Airline Quality Rating 2001, reflects monthly Airline Quality Rating scores for 2000. AQR scores for the calendar year 2000 are based on 15 elements that focus on airline performance areas important to air travel consumers. The Airline Quality Rating 2001 is a summary of month-by-month quality ra...

  17. Dynamic Appliances Scheduling in Collaborative MicroGrids System

    Science.gov (United States)

    Bilil, Hasnae; Aniba, Ghassane; Gharavi, Hamid

    2017-01-01

    In this paper a new approach which is based on a collaborative system of MicroGrids (MG’s), is proposed to enable household appliance scheduling. To achieve this, appliances are categorized into flexible and non-flexible Deferrable Loads (DL’s), according to their electrical components. We propose a dynamic scheduling algorithm where users can systematically manage the operation of their electric appliances. The main challenge is to develop a flattening function calculus (reshaping) for both flexible and non-flexible DL’s. In addition, implementation of the proposed algorithm would require dynamically analyzing two successive multi-objective optimization (MOO) problems. The first targets the activation schedule of non-flexible DL’s and the second deals with the power profiles of flexible DL’s. The MOO problems are resolved by using a fast and elitist multi-objective genetic algorithm (NSGA-II). Finally, in order to show the efficiency of the proposed approach, a case study of a collaborative system that consists of 40 MG’s registered in the load curve for the flattening program has been developed. The results verify that the load curve can indeed become very flat by applying the proposed scheduling approach. PMID:28824226

  18. Location-Price Competition in Airline Networks

    Directory of Open Access Journals (Sweden)

    H. Gao

    2014-01-01

    Full Text Available This paper addresses location-then-price competition in airline market as a two-stage game of n players on the graph. Passenger’s demand distribution is described by multinomial logit model. Equilibrium in price game is computed through best response dynamics. We solve location game using backward induction, knowing that airlines will choose prices from equilibrium for the second-stage game. Some numerical results for airline market under consideration are presented.

  19. Dynamic Intelligent Feedback Scheduling in Networked Control Systems

    Directory of Open Access Journals (Sweden)

    Hui-ying Chen

    2013-01-01

    Full Text Available For the networked control system with limited bandwidth and flexible workload, a dynamic intelligent feedback scheduling strategy is proposed. Firstly, a monitor is used to acquire the current available network bandwidth. Then, the new available bandwidth in the next interval is predicted by using LS_SVM approach. At the same time, the dynamic performance indices of all control loops are obtained with a two-dimensional fuzzy logic modulator. Finally, the predicted network bandwidth is dynamically allocated by the bandwidth manager and the priority allocator in terms of the loops' dynamic performance indices. Simulation results show that the sampling periods and priorities of control loops are adjusted timely according to the network workload condition and the dynamic performance of control loops, which make the system running in the optimal state all the time.

  20. Heuristic Scheduling Algorithm Oriented Dynamic Tasks for Imaging Satellites

    Directory of Open Access Journals (Sweden)

    Maocai Wang

    2014-01-01

    Full Text Available Imaging satellite scheduling is an NP-hard problem with many complex constraints. This paper researches the scheduling problem for dynamic tasks oriented to some emergency cases. After the dynamic properties of satellite scheduling were analyzed, the optimization model is proposed in this paper. Based on the model, two heuristic algorithms are proposed to solve the problem. The first heuristic algorithm arranges new tasks by inserting or deleting them, then inserting them repeatedly according to the priority from low to high, which is named IDI algorithm. The second one called ISDR adopts four steps: insert directly, insert by shifting, insert by deleting, and reinsert the tasks deleted. Moreover, two heuristic factors, congestion degree of a time window and the overlapping degree of a task, are employed to improve the algorithm’s performance. Finally, a case is given to test the algorithms. The results show that the IDI algorithm is better than ISDR from the running time point of view while ISDR algorithm with heuristic factors is more effective with regard to algorithm performance. Moreover, the results also show that our method has good performance for the larger size of the dynamic tasks in comparison with the other two methods.

  1. Dynamic Planning of Experiments for the Optimisation of Managerial Scheduling

    Directory of Open Access Journals (Sweden)

    Tomáš Macák

    2016-01-01

    Full Text Available Time management has a crucial role in organizations and also in our personal lives. Managerial scheduling is an important tool for the time management, especially It can serve as a tool for the first phase, of time management - namely for effective planning. This paper focusses on finding the best possible setting for determining significant the best layout for activities according to the criteria of urgency and importance using a modified steepest ascent method, which can be referred as dynamic scheduling. This term indicates the nature of the method; wherein the experimental design space is changed to look for the best conditions for adjustment factors influencing a managerial process. Existing methods for layout optimization mentioned in the literature and conventionally implemented in practice have only shown local optima.

  2. Coordinated scheduling for dynamic real-time systems

    Science.gov (United States)

    Natarajan, Swaminathan; Zhao, Wei

    1994-01-01

    In this project, we addressed issues in coordinated scheduling for dynamic real-time systems. In particular, we concentrated on design and implementation of a new distributed real-time system called R-Shell. The design objective of R-Shell is to provide computing support for space programs that have large, complex, fault-tolerant distributed real-time applications. In R-shell, the approach is based on the concept of scheduling agents, which reside in the application run-time environment, and are customized to provide just those resource management functions which are needed by the specific application. With this approach, we avoid the need for a sophisticated OS which provides a variety of generalized functionality, while still not burdening application programmers with heavy responsibility for resource management. In this report, we discuss the R-Shell approach, summarize the achievement of the project, and describe a preliminary prototype of R-Shell system.

  3. Airline Quality Rating 1996

    OpenAIRE

    Bowen, Brent D.; Headley, Dean E.

    1996-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline performance on combined multiple factors important to consumers. Development history and calculation details for the AQR rating system are detailed in The Airline Quality Rating issued in April, 1991, by the National Institute for Aviation Research at Wichita State University. This current report, Airline Quality Rating 1996, contains monthly Airline Quality Rating scor...

  4. Applying dynamic priority scheduling scheme to static systems of pinwheel task model in power-aware scheduling.

    Science.gov (United States)

    Seol, Ye-In; Kim, Young-Kuk

    2014-01-01

    Power-aware scheduling reduces CPU energy consumption in hard real-time systems through dynamic voltage scaling (DVS). In this paper, we deal with pinwheel task model which is known as static and predictable task model and could be applied to various embedded or ubiquitous systems. In pinwheel task model, each task's priority is static and its execution sequence could be predetermined. There have been many static approaches to power-aware scheduling in pinwheel task model. But, in this paper, we will show that the dynamic priority scheduling results in power-aware scheduling could be applied to pinwheel task model. This method is more effective than adopting the previous static priority scheduling methods in saving energy consumption and, for the system being still static, it is more tractable and applicable to small sized embedded or ubiquitous computing. Also, we introduce a novel power-aware scheduling algorithm which exploits all slacks under preemptive earliest-deadline first scheduling which is optimal in uniprocessor system. The dynamic priority method presented in this paper could be applied directly to static systems of pinwheel task model. The simulation results show that the proposed algorithm with the algorithmic complexity of O(n) reduces the energy consumption by 10-80% over the existing algorithms.

  5. Off-Line and Dynamic Production Scheduling – A Comparative Case Study

    OpenAIRE

    Bożek Andrzej; Wysocki Marian

    2016-01-01

    A comprehensive case study of manufacturing scheduling solutions development is given. It includes highly generalized scheduling problem as well as a few scheduling modes, methods and problem models. The considered problem combines flexible job shop structure, lot streaming with variable sublots, transport times, setup times, and machine calendars. Tabu search metaheuristic and constraint programming methods have been used for the off-line scheduling. Two dynamic scheduling methods have also ...

  6. Airline Operations Aid

    Science.gov (United States)

    1993-01-01

    C Language Integrated Production System (CLIPS), a NASA-developed expert systems program, is used by American Airlines for three purposes: as a rapid prototyping tool; to develop production prototypes; and to develop production application. An example of the latter is CLIPS' use in "Hub S1AAshing," a knowledge based system that recommends contingency plans when severe schedule reductions must be made. Hub S1AAshing has replaced a manual, labor intensive process. It saves time and allows Operations Control Coordinators to handle more difficult situations. Because the system assimilates much of the information necessary to facilitate educated decision making, it minimizes negative impact in situations where it is impossible to operate all flights.

  7. Adaptive Dynamic Process Scheduling on Distributed Memory Parallel Computers

    Directory of Open Access Journals (Sweden)

    Wei Shu

    1994-01-01

    Full Text Available One of the challenges in programming distributed memory parallel machines is deciding how to allocate work to processors. This problem is particularly important for computations with unpredictable dynamic behaviors or irregular structures. We present a scheme for dynamic scheduling of medium-grained processes that is useful in this context. The adaptive contracting within neighborhood (ACWN is a dynamic, distributed, load-dependent, and scalable scheme. It deals with dynamic and unpredictable creation of processes and adapts to different systems. The scheme is described and contrasted with two other schemes that have been proposed in this context, namely the randomized allocation and the gradient model. The performance of the three schemes on an Intel iPSC/2 hypercube is presented and analyzed. The experimental results show that even though the ACWN algorithm incurs somewhat larger overhead than the randomized allocation, it achieves better performance in most cases due to its adaptiveness. Its feature of quickly spreading the work helps it outperform the gradient model in performance and scalability.

  8. Humanoid Walking Robot: Modeling, Inverse Dynamics, and Gain Scheduling Control

    Directory of Open Access Journals (Sweden)

    Elvedin Kljuno

    2010-01-01

    Full Text Available This article presents reference-model-based control design for a 10 degree-of-freedom bipedal walking robot, using nonlinear gain scheduling. The main goal is to show concentrated mass models can be used for prediction of the required joint torques for a bipedal walking robot. Relatively complicated architecture, high DOF, and balancing requirements make the control task of these robots difficult. Although linear control techniques can be used to control bipedal robots, nonlinear control is necessary for better performance. The emphasis of this work is to show that the reference model can be a bipedal walking model with concentrated mass at the center of gravity, which removes the problems related to design of a pseudo-inverse system. Another significance of this approach is the reduced calculation requirements due to the simplified procedure of nominal joint torques calculation. Kinematic and dynamic analysis is discussed including results for joint torques and ground force necessary to implement a prescribed walking motion. This analysis is accompanied by a comparison with experimental data. An inverse plant and a tracking error linearization-based controller design approach is described. We propose a novel combination of a nonlinear gain scheduling with a concentrated mass model for the MIMO bipedal robot system.

  9. Esindusteenuseid pakub Airline Management

    Index Scriptorium Estoniae

    2007-01-01

    Lennufirmadele ja teistele turismivaldkonna ettevõtetele esindusteenuseid pakkuvast firmast Airline Management OÜ. Firma poolt Eestis esindatud lennufirmade Air Namibia, SN Brussels Airlines ja Flynordic ning hotelligrupi Wyndham lühitutvustus

  10. Managing airlines: the cost of complexity

    Energy Technology Data Exchange (ETDEWEB)

    Trapote-Barreira, C.; Deutschmann, A.; Robuste, F.

    2016-07-01

    This paper is dedicated to the structure of airline networks as a sink of efficient airline operations. Parameters of complexity were derived and mirrored on level of service as well as efficiency parameters. Airlines usually considerers an operational overhead to predict the total flight operation cost. This parameter includes the expected cost for disruptions and delays. When an airline has to mobilize an aircraft in a base for recovering the service or for breaking an emergent dynamic, then it is running extra costs. The cost of managing complexity in the airline industry has a direct impact on profit and loss account. Therefore, this paper presents an integrated approach to evaluate this cost, based on padding and aircrafts dedicated to recover disruptions. Finally, some additional indicators are derived to evaluate reliability improvement as part of complex performance. (Author)

  11. Solving a robust airline crew pairing problem with column generation

    NARCIS (Netherlands)

    Muter, I.; Birbil, S.I.; Bülbül, K.; Sahin, G.; Yenigün, H.; Tas, D.; Tüzün, D.

    2013-01-01

    In this study, we solve a robust version of the airline crew pairing problem. Our concept of robustness was partially shaped during our discussions with small local airlines in Turkey which may have to add a set of extra flights into their schedule at short notice during operation. Thus, robustness

  12. Dynamic Vehicle Scheduling for Working Service Network with Dual Demands

    Directory of Open Access Journals (Sweden)

    Bing Li

    2017-01-01

    Full Text Available This study aims to develop some models to aid in making decisions on the combined fleet size and vehicle assignment in working service network where the demands include two types (minimum demands and maximum demands, and vehicles themselves can act like a facility to provide services when they are stationary at one location. This type of problem is named as the dynamic working vehicle scheduling with dual demands (DWVS-DD and formulated as a mixed integer programming (MIP. Instead of a large integer program, the problem is decomposed into small local problems that are guided by preset control parameters. The approach for preset control parameters is given. By introducing them into the MIP formulation, the model is reformulated as a piecewise form. Further, a piecewise method by updating preset control parameters is proposed for solving the reformulated model. Numerical experiments show that the proposed method produces better solution within reasonable computing time.

  13. Approximate dynamic programming approaches for appointment scheduling with patient preferences.

    Science.gov (United States)

    Li, Xin; Wang, Jin; Fung, Richard Y K

    2018-04-01

    During the appointment booking process in out-patient departments, the level of patient satisfaction can be affected by whether or not their preferences can be met, including the choice of physicians and preferred time slot. In addition, because the appointments are sequential, considering future possible requests is also necessary for a successful appointment system. This paper proposes a Markov decision process model for optimizing the scheduling of sequential appointments with patient preferences. In contrast to existing models, the evaluation of a booking decision in this model focuses on the extent to which preferences are satisfied. Characteristics of the model are analysed to develop a system for formulating booking policies. Based on these characteristics, two types of approximate dynamic programming algorithms are developed to avoid the curse of dimensionality. Experimental results suggest directions for further fine-tuning of the model, as well as improving the efficiency of the two proposed algorithms. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Residential Consumption Scheduling Based on Dynamic User Profiling

    Science.gov (United States)

    Mangiatordi, Federica; Pallotti, Emiliano; Del Vecchio, Paolo; Capodiferro, Licia

    Deployment of household appliances and of electric vehicles raises the electricity demand in the residential areas and the impact of the building's electrical power. The variations of electricity consumption across the day, may affect both the design of the electrical generation facilities and the electricity bill, mainly when a dynamic pricing is applied. This paper focuses on an energy management system able to control the day-ahead electricity demand in a residential area, taking into account both the variability of the energy production costs and the profiling of the users. The user's behavior is dynamically profiled on the basis of the tasks performed during the previous days and of the tasks foreseen for the current day. Depending on the size and on the flexibility in time of the user tasks, home inhabitants are grouped in, one over N, energy profiles, using a k-means algorithm. For a fixed energy generation cost, each energy profile is associated to a different hourly energy cost. The goal is to identify any bad user profile and to make it pay a highest bill. A bad profile example is when a user applies a lot of consumption tasks and low flexibility in task reallocation time. The proposed energy management system automatically schedules the tasks, solving a multi-objective optimization problem based on an MPSO strategy. The goals, when identifying bad users profiles, are to reduce the peak to average ratio in energy demand, and to minimize the energy costs, promoting virtuous behaviors.

  15. Airlines 2.0

    OpenAIRE

    Hvass, Kristian A.; Munar, Ana María

    2014-01-01

    Over the years online marketing has grown in importance in the airline industry. This media space offers airlines numerous marketing tools, one of the most recent being social media. Social media allows airlines to interact directly with customers via various Internet platforms, and monitor customer opinions and evaluations of services. This exploratory paper studies airlines’ use of social media on Facebook and Twitter for a defined period of time. The paper analyses the content of social me...

  16. The Office of Airline Information.

    Science.gov (United States)

    2015-01-01

    The Office of Airline Information (OAI) mandate is to collect, validate, compile and disseminate data on airline traffic, performance, finances, and fares. Each quarter, BTS Office of Airline Information (OAI) processes more than 3,800 filings sub...

  17. Persistence of airline accidents.

    Science.gov (United States)

    Barros, Carlos Pestana; Faria, Joao Ricardo; Gil-Alana, Luis Alberiko

    2010-10-01

    This paper expands on air travel accident research by examining the relationship between air travel accidents and airline traffic or volume in the period from 1927-2006. The theoretical model is based on a representative airline company that aims to maximise its profits, and it utilises a fractional integration approach in order to determine whether there is a persistent pattern over time with respect to air accidents and air traffic. Furthermore, the paper analyses how airline accidents are related to traffic using a fractional cointegration approach. It finds that airline accidents are persistent and that a (non-stationary) fractional cointegration relationship exists between total airline accidents and airline passengers, airline miles and airline revenues, with shocks that affect the long-run equilibrium disappearing in the very long term. Moreover, this relation is negative, which might be due to the fact that air travel is becoming safer and there is greater competition in the airline industry. Policy implications are derived for countering accident events, based on competition and regulation. © 2010 The Author(s). Journal compilation © Overseas Development Institute, 2010.

  18. Off-Line and Dynamic Production Scheduling – A Comparative Case Study

    Directory of Open Access Journals (Sweden)

    Bożek Andrzej

    2016-03-01

    Full Text Available A comprehensive case study of manufacturing scheduling solutions development is given. It includes highly generalized scheduling problem as well as a few scheduling modes, methods and problem models. The considered problem combines flexible job shop structure, lot streaming with variable sublots, transport times, setup times, and machine calendars. Tabu search metaheuristic and constraint programming methods have been used for the off-line scheduling. Two dynamic scheduling methods have also been implemented, i.e., dispatching rules for the completely reactive scheduling and a multi-agent system for the predictivereactive scheduling. In these implementations three distinct models of the problem have been used, based on: graph representation, optimal constraint satisfaction, and Petri net formalism. Each of these solutions has been verified in computational experiments. The results are compared and some findings about advantages, disadvantages, and suggestions on using the solutions are formulated.

  19. Heuristic algorithm for single resource constrained project scheduling problem based on the dynamic programming

    Directory of Open Access Journals (Sweden)

    Stanimirović Ivan

    2009-01-01

    Full Text Available We introduce a heuristic method for the single resource constrained project scheduling problem, based on the dynamic programming solution of the knapsack problem. This method schedules projects with one type of resources, in the non-preemptive case: once started an activity is not interrupted and runs to completion. We compare the implementation of this method with well-known heuristic scheduling method, called Minimum Slack First (known also as Gray-Kidd algorithm, as well as with Microsoft Project.

  20. Dynamic scheduling and analysis of real time systems with multiprocessors

    Directory of Open Access Journals (Sweden)

    M.D. Nashid Anjum

    2016-08-01

    Full Text Available This research work considers a scenario of cloud computing job-shop scheduling problems. We consider m realtime jobs with various lengths and n machines with different computational speeds and costs. Each job has a deadline to be met, and the profit of processing a packet of a job differs from other jobs. Moreover, considered deadlines are either hard or soft and a penalty is applied if a deadline is missed where the penalty is considered as an exponential function of time. The scheduling problem has been formulated as a mixed integer non-linear programming problem whose objective is to maximize net-profit. The formulated problem is computationally hard and not solvable in deterministic polynomial time. This research work proposes an algorithm named the Tube-tap algorithm as a solution to this scheduling optimization problem. Extensive simulation shows that the proposed algorithm outperforms existing solutions in terms of maximizing net-profit and preserving deadlines.

  1. Concurrent variable-interval variable-ratio schedules in a dynamic choice environment.

    Science.gov (United States)

    Bell, Matthew C; Baum, William M

    2017-11-01

    Most studies of operant choice have focused on presenting subjects with a fixed pair of schedules across many experimental sessions. Using these methods, studies of concurrent variable- interval variable-ratio schedules helped to evaluate theories of choice. More recently, a growing literature has focused on dynamic choice behavior. Those dynamic choice studies have analyzed behavior on a number of different time scales using concurrent variable-interval schedules. Following the dynamic choice approach, the present experiment examined performance on concurrent variable-interval variable-ratio schedules in a rapidly changing environment. Our objectives were to compare performance on concurrent variable-interval variable-ratio schedules with extant data on concurrent variable-interval variable-interval schedules using a dynamic choice procedure and to extend earlier work on concurrent variable-interval variable-ratio schedules. We analyzed performances at different time scales, finding strong similarities between concurrent variable-interval variable-interval and concurrent variable-interval variable- ratio performance within dynamic choice procedures. Time-based measures revealed almost identical performance in the two procedures compared with response-based measures, supporting the view that choice is best understood as time allocation. Performance at the smaller time scale of visits accorded with the tendency seen in earlier research toward developing a pattern of strong preference for and long visits to the richer alternative paired with brief "samples" at the leaner alternative ("fix and sample"). © 2017 Society for the Experimental Analysis of Behavior.

  2. A Scheduling Algorithm for Cloud Computing System Based on the Driver of Dynamic Essential Path.

    Science.gov (United States)

    Xie, Zhiqiang; Shao, Xia; Xin, Yu

    2016-01-01

    To solve the problem of task scheduling in the cloud computing system, this paper proposes a scheduling algorithm for cloud computing based on the driver of dynamic essential path (DDEP). This algorithm applies a predecessor-task layer priority strategy to solve the problem of constraint relations among task nodes. The strategy assigns different priority values to every task node based on the scheduling order of task node as affected by the constraint relations among task nodes, and the task node list is generated by the different priority value. To address the scheduling order problem in which task nodes have the same priority value, the dynamic essential long path strategy is proposed. This strategy computes the dynamic essential path of the pre-scheduling task nodes based on the actual computation cost and communication cost of task node in the scheduling process. The task node that has the longest dynamic essential path is scheduled first as the completion time of task graph is indirectly influenced by the finishing time of task nodes in the longest dynamic essential path. Finally, we demonstrate the proposed algorithm via simulation experiments using Matlab tools. The experimental results indicate that the proposed algorithm can effectively reduce the task Makespan in most cases and meet a high quality performance objective.

  3. HOLD MODE BASED DYNAMIC PRIORITY LOAD ADAPTIVE INTERPICONET SCHEDULING FOR BLUETOOTH SCATTERNETS

    Directory of Open Access Journals (Sweden)

    G.S. Mahalakshmi

    2011-09-01

    Full Text Available Scheduling in piconets has emerged as a challenging research area. Interpiconet scheduling focuses on when a bridge is switched among various piconets and how a bridge node communicates with the masters in different piconets. This paper proposes an interpiconet scheduling algorithm named, hold mode based dynamic traffic priority load adaptive scheduling. The bridges are adaptively switched between the piconets according to various traffic loads. The main goal is to maximize the utilization of the bridge by reducing the bridge switch wastes, utilize intelligent decision making algorithm, resolve conflict between the masters, and allow negotiation for bridge utilization in HDPLIS using bridge failure-bridge repair procedure . The Hold mode - dynamic traffic - priority based - load adaptive scheduling reduces the number of bridge switch wastes and hence increases the efficiency of the bridge which results in increased performance of the system.

  4. On the number of different dynamics in Boolean networks with deterministic update schedules.

    Science.gov (United States)

    Aracena, J; Demongeot, J; Fanchon, E; Montalva, M

    2013-04-01

    Deterministic Boolean networks are a type of discrete dynamical systems widely used in the modeling of genetic networks. The dynamics of such systems is characterized by the local activation functions and the update schedule, i.e., the order in which the nodes are updated. In this paper, we address the problem of knowing the different dynamics of a Boolean network when the update schedule is changed. We begin by proving that the problem of the existence of a pair of update schedules with different dynamics is NP-complete. However, we show that certain structural properties of the interaction diagraph are sufficient for guaranteeing distinct dynamics of a network. In [1] the authors define equivalence classes which have the property that all the update schedules of a given class yield the same dynamics. In order to determine the dynamics associated to a network, we develop an algorithm to efficiently enumerate the above equivalence classes by selecting a representative update schedule for each class with a minimum number of blocks. Finally, we run this algorithm on the well known Arabidopsis thaliana network to determine the full spectrum of its different dynamics. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Calculating load factors for the transatlantic airline market using supply and demand data: a note on the identification of gaps in the available airline statistics

    NARCIS (Netherlands)

    Devriendt, L.; Burghouwt, G.; Derudder, B.; de Wit, J.; Witlox, F.

    2009-01-01

    This paper takes a critical view of the verification of load factors for the direct transatlantic airline market by combining supply and demand-data. The supply-related data originate from the Official Airline Guide, a well-known data source that contains information on scheduled flights. The

  6. Airline meteorological requirements

    Science.gov (United States)

    Chandler, C. L.; Pappas, J.

    1985-01-01

    A brief review of airline meteorological/flight planning is presented. The effects of variations in meteorological parameters upon flight and operational costs are reviewed. Flight path planning through the use of meteorological information is briefly discussed.

  7. Airline Crew Training

    Science.gov (United States)

    1989-01-01

    The discovery that human error has caused many more airline crashes than mechanical malfunctions led to an increased emphasis on teamwork and coordination in airline flight training programs. Human factors research at Ames Research Center has produced two crew training programs directed toward more effective operations. Cockpit Resource Management (CRM) defines areas like decision making, workload distribution, communication skills, etc. as essential in addressing human error problems. In 1979, a workshop led to the implementation of the CRM program by United Airlines, and later other airlines. In Line Oriented Flight Training (LOFT), crews fly missions in realistic simulators while instructors induce emergency situations requiring crew coordination. This is followed by a self critique. Ames Research Center continues its involvement with these programs.

  8. Factors of Airline Marketing

    Directory of Open Access Journals (Sweden)

    Ivan Mišetić

    2007-01-01

    Full Text Available The paper addresses several marketing related notions associatedwith airline strategic planning and positioning. Besideexamining the distinctions between network operator and nicheplayer, this paper treats the state of Croatia Airlines within thereported AEA benchmarking of the specific elements of airlinebusiness. It also studies certain aspects of the air market that influencepricing and demand elasticity, such as the impact oflow cost carriers and the practice of network hubbing.

  9. airline revenue management

    OpenAIRE

    Pak, K.; Piersma, Nanda

    2002-01-01

    textabstractWith the increasing interest in decision support systems and the continuous advance of computer science, revenue management is a discipline which has received a great deal of interest in recent years. Although revenue management has seen many new applications throughout the years, the main focus of research continues to be the airline industry. Ever since Littlewood (1972) first proposed a solution method for the airline revenue management problem, a variety of solution methods ha...

  10. Disruption management in the airline industry-Concepts, models and methods

    DEFF Research Database (Denmark)

    Clausen, Jens; Larsen, Allan; Larsen, Jesper

    2010-01-01

    This paper provides a thorough review of the current state-of-the-art within airline disruption management of resources, including aircraft, crew, passenger and integrated recovery. An overview of model formulations of the aircraft and crew scheduling problems is presented in order to emphasize...... similarities between solution approaches applied to the planning and recovery problems. A brief overview of research within schedule robustness in airline scheduling is included in the review, since this proactive measure is a natural complement to disruption management....

  11. Dynamic Hierarchical Sleep Scheduling for Wireless Ad-Hoc Sensor Networks

    OpenAIRE

    Chih-Yu Wen; Ying-Chih Chen

    2009-01-01

    This paper presents two scheduling management schemes for wireless sensor networks, which manage the sensors by utilizing the hierarchical network structure and allocate network resources efficiently. A local criterion is used to simultaneously establish the sensing coverage and connectivity such that dynamic cluster-based sleep scheduling can be achieved. The proposed schemes are simulated and analyzed to abstract the network behaviors in a number of settings. The experimental results show t...

  12. Comparison of airline passenger oxygen systems.

    Science.gov (United States)

    Byrne, N J

    1995-08-01

    The principal sources of oxygen for inflight passenger use, scheduled and unscheduled, are examined. Present practices of assessment of the passenger's "fitness to fly" are described. Three partner airlines, British Airways, U.S. Air, and Qantas, catering for more than 8000 oxygen requests annually, are compared. Analysis of customer use suggests that medical oxygen requests are frequently not clinically justified. The growth in demand, for both scheduled and unscheduled use of an expensive resource, supports the need for a "recommended best practice" among carriers. Passengers with respiratory disorders who will most benefit from inflight oxygen are vulnerable either to hypoxia or asthma.

  13. Proving deadlock freedom of logic programs with dynamic scheduling

    NARCIS (Netherlands)

    E. Marchiori; F. Teusink (Frank)

    1996-01-01

    textabstractIn increasingly many logic programming systems, the Prolog left to right selection rule has been replaced with dynamic selection rules, that select an atom of a query among those satisfying suitable conditions. These conditions describe the form of the arguments of every program

  14. Key drivers of airline loyalty.

    Science.gov (United States)

    Dolnicar, Sara; Grabler, Klaus; Grün, Bettina; Kulnig, Anna

    2011-10-01

    This study investigates drivers of airline loyalty. It contributes to the body of knowledge in the area by investigating loyalty for a number of a priori market segments identified by airline management and by using a method which accounts for the multi-step nature of the airline choice process. The study is based on responses from 687 passengers. Results indicate that, at aggregate level, frequent flyer membership, price, the status of being a national carrier and the reputation of the airline as perceived by friends are the variables which best discriminate between travellers loyal to the airline and those who are not. Differences in drivers of airline loyalty for a number of segments were identified. For example, loyalty programs play a key role for business travellers whereas airline loyalty of leisure travellers is difficult to trace back to single factors. For none of the calculated models satisfaction emerged as a key driver of airline loyalty.

  15. A Variable Interval Rescheduling Strategy for Dynamic Flexible Job Shop Scheduling Problem by Improved Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2017-01-01

    Full Text Available In real-world manufacturing systems, production scheduling systems are often implemented under random or dynamic events like machine failure, unexpected processing times, stochastic arrival of the urgent orders, cancellation of the orders, and so on. These dynamic events will lead the initial scheduling scheme to be nonoptimal and/or infeasible. Hence, appropriate dynamic rescheduling approaches are needed to overcome the dynamic events. In this paper, we propose a dynamic rescheduling method based on variable interval rescheduling strategy (VIRS to deal with the dynamic flexible job shop scheduling problem considering machine failure, urgent job arrival, and job damage as disruptions. On the other hand, an improved genetic algorithm (GA is proposed for minimizing makespan. In our improved GA, a mix of random initialization population by combining initialization machine and initialization operation with random initialization is designed for generating high-quality initial population. In addition, the elitist strategy (ES and improved population diversity strategy (IPDS are used to avoid falling into the local optimal solution. Experimental results for static and several dynamic events in the FJSP show that our method is feasible and effective.

  16. Heuristics in dynamic scheduling : A practical framework with a case study in elevator dispatching

    NARCIS (Netherlands)

    De Jong, J.L.

    2012-01-01

    Dynamic scheduling problems are ubiquitous: traffic lights, elevators, planning of manufacturing plants, air traffic control, etc. Tasks have to be put on a timeline as smart as possible to reach certain goals. These goals may be related to production costs, the use of (scarce) resources, deadlines.

  17. Decomposition principles applied to the dynamic production and work-force scheduling problem

    NARCIS (Netherlands)

    Aardal, K.I.; Ari, A.

    1987-01-01

    One of the most important problems in the production and inventory planning field, is the scheduling of production and work force in a dynamic environment. Although this problem can be formulated as a linear program, it is often quite difficult to solve directly, due to its large scale. Instead, it

  18. A Simple Method for Dynamic Scheduling in a Heterogeneous Computing System

    OpenAIRE

    Žumer, Viljem; Brest, Janez

    2002-01-01

    A simple method for the dynamic scheduling on a heterogeneous computing system is proposed in this paper. It was implemented to minimize the parallel program execution time. The proposed method decomposes the program workload into computationally homogeneous subtasks, which may be of the different size, depending on the current load of each machine in a heterogeneous computing system.

  19. Dynamic Sleep Scheduling on Air Pollution Levels Monitoring with Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Gezaq Abror

    2018-01-01

    Full Text Available Wireless Sensor Network (WSN can be applied for Air Pollution Level Monitoring System that have been determined by the Environmental Impact Management Agency which is  PM10, SO2, O3, NO2 and CO. In WSN, node system is constrained to a limited power supply, so that the node system has a lifetime. To doing lifetime maximization, power management scheme is required and sensor nodes should use energy efficiently. This paper proposes dynamic sleep scheduling using Time Category-Fuzzy Logic (Time-Fuzzy Scheduling as a reference for calculating time interval for sleep and activated node system to support power management scheme. This research contributed in power management design to be applied to the WSN system to reduce energy expenditure. From the test result in real hardware node system, it can be seen that Time-Fuzzy Scheduling is better in terms of using the battery and it is better in terms of energy consumption too because it is more efficient 51.85% when it is compared with Fuzzy Scheduling, it is more efficient 68.81% when it is compared with Standard Scheduling and it is more efficient 85.03% when compared with No Scheduling.

  20. An FMS Dynamic Production Scheduling Algorithm Considering Cutting Tool Failure and Cutting Tool Life

    International Nuclear Information System (INIS)

    Setiawan, A; Wangsaputra, R; Halim, A H; Martawirya, Y Y

    2016-01-01

    This paper deals with Flexible Manufacturing System (FMS) production rescheduling due to unavailability of cutting tools caused either of cutting tool failure or life time limit. The FMS consists of parallel identical machines integrated with an automatic material handling system and it runs fully automatically. Each machine has a same cutting tool configuration that consists of different geometrical cutting tool types on each tool magazine. The job usually takes two stages. Each stage has sequential operations allocated to machines considering the cutting tool life. In the real situation, the cutting tool can fail before the cutting tool life is reached. The objective in this paper is to develop a dynamic scheduling algorithm when a cutting tool is broken during unmanned and a rescheduling needed. The algorithm consists of four steps. The first step is generating initial schedule, the second step is determination the cutting tool failure time, the third step is determination of system status at cutting tool failure time and the fourth step is the rescheduling for unfinished jobs. The approaches to solve the problem are complete-reactive scheduling and robust-proactive scheduling. The new schedules result differences starting time and completion time of each operations from the initial schedule. (paper)

  1. Generation of Look-Up Tables for Dynamic Job Shop Scheduling Decision Support Tool

    Science.gov (United States)

    Oktaviandri, Muchamad; Hassan, Adnan; Mohd Shaharoun, Awaluddin

    2016-02-01

    Majority of existing scheduling techniques are based on static demand and deterministic processing time, while most job shop scheduling problem are concerned with dynamic demand and stochastic processing time. As a consequence, the solutions obtained from the traditional scheduling technique are ineffective wherever changes occur to the system. Therefore, this research intends to develop a decision support tool (DST) based on promising artificial intelligent that is able to accommodate the dynamics that regularly occur in job shop scheduling problem. The DST was designed through three phases, i.e. (i) the look-up table generation, (ii) inverse model development and (iii) integration of DST components. This paper reports the generation of look-up tables for various scenarios as a part in development of the DST. A discrete event simulation model was used to compare the performance among SPT, EDD, FCFS, S/OPN and Slack rules; the best performances measures (mean flow time, mean tardiness and mean lateness) and the job order requirement (inter-arrival time, due dates tightness and setup time ratio) which were compiled into look-up tables. The well-known 6/6/J/Cmax Problem from Muth and Thompson (1963) was used as a case study. In the future, the performance measure of various scheduling scenarios and the job order requirement will be mapped using ANN inverse model.

  2. Dynamic Hierarchical Sleep Scheduling for Wireless Ad-Hoc Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chih-Yu Wen

    2009-05-01

    Full Text Available This paper presents two scheduling management schemes for wireless sensor networks, which manage the sensors by utilizing the hierarchical network structure and allocate network resources efficiently. A local criterion is used to simultaneously establish the sensing coverage and connectivity such that dynamic cluster-based sleep scheduling can be achieved. The proposed schemes are simulated and analyzed to abstract the network behaviors in a number of settings. The experimental results show that the proposed algorithms provide efficient network power control and can achieve high scalability in wireless sensor networks.

  3. Dynamic hierarchical sleep scheduling for wireless ad-hoc sensor networks.

    Science.gov (United States)

    Wen, Chih-Yu; Chen, Ying-Chih

    2009-01-01

    This paper presents two scheduling management schemes for wireless sensor networks, which manage the sensors by utilizing the hierarchical network structure and allocate network resources efficiently. A local criterion is used to simultaneously establish the sensing coverage and connectivity such that dynamic cluster-based sleep scheduling can be achieved. The proposed schemes are simulated and analyzed to abstract the network behaviors in a number of settings. The experimental results show that the proposed algorithms provide efficient network power control and can achieve high scalability in wireless sensor networks.

  4. A SCHEDULING SCHEME WITH DYNAMIC FREQUENCY CLOCKING AND MULTIPLE VOLTAGES FOR LOW POWER DESIGNS

    Institute of Scientific and Technical Information of China (English)

    Wen Dongxin; Wang Ling; Yang Xiaozong

    2007-01-01

    In this letter, a scheduling scheme based on Dynamic Frequency Clocking (DFC) and multiple voltages is proposed for low power designs under the timing and the resource constraints.Unlike the conventional methods at high level synthesis where only voltages of nodes were considered,the scheme based on a gain function considers both voltage and frequency simultaneously to reduce energy consumption. Experiments with a number of DSP benchmarks show that the proposed scheme achieves an effective energy reduction.

  5. Robustness of airline route networks

    Science.gov (United States)

    Lordan, Oriol; Sallan, Jose M.; Escorihuela, Nuria; Gonzalez-Prieto, David

    2016-03-01

    Airlines shape their route network by defining their routes through supply and demand considerations, paying little attention to network performance indicators, such as network robustness. However, the collapse of an airline network can produce high financial costs for the airline and all its geographical area of influence. The aim of this study is to analyze the topology and robustness of the network route of airlines following Low Cost Carriers (LCCs) and Full Service Carriers (FSCs) business models. Results show that FSC hubs are more central than LCC bases in their route network. As a result, LCC route networks are more robust than FSC networks.

  6. Justice Department Airline Merger Policy

    Science.gov (United States)

    Farmer, D. A.

    1972-01-01

    Justice Department airline merger policy is developed within the context of the Federal Aviation Act, in which there is an unusually explicit reliance on competition as a means of fulfilling statutory goals. The economics of the airline industry appear to indicate that low concentration and vigorous competition are particularly viable and desirable. Several factors, including existing regulatory policy, create incentives for airlines to merge whether or not an individual merger promotes or conflicts with the public interest. Specific benefits to the public should be identified and shown to clearly outweight the detriments, including adverse competitive impact, in order for airline mergers to be approved.

  7. Airline Deregulation and Public Policy

    Science.gov (United States)

    Morrison, Steven A.; Winston, Clifford

    1989-08-01

    An assessment of the effects of airline deregulation on travelers and carriers indicates that deregulation has provided travelers and carriers with 14.9 billion of annual benefits (1988 dollars). Airport congestion, airline safety, airline bankruptcy, and mergers are also analyzed and found in most cases to have reduced benefits. But, these costs should not be attributed to deregulation per se, but to failures by the government to pursue appropriate policies in these areas. Pursuit of policies that promote airline competition and efficient use of airport capacity would significantly increase the benefits from deregulation and would provide valuable guidance for other industries undergoing the transition to deregulation.

  8. Improved Weather Forecasting for the Dynamic Scheduling System of the Green Bank Telescope

    Science.gov (United States)

    Henry, Kari; Maddalena, Ronald

    2018-01-01

    The Robert C Byrd Green Bank Telescope (GBT) uses a software system that dynamically schedules observations based on models of vertical weather forecasts produced by the National Weather Service (NWS). The NWS provides hourly forecasted values for ~60 layers that extend into the stratosphere over the observatory. We use models, recommended by the Radiocommunication Sector of the International Telecommunications Union, to derive the absorption coefficient in each layer for each hour in the NWS forecasts and for all frequencies over which the GBT has receivers, 0.1 to 115 GHz. We apply radiative transfer models to derive the opacity and the atmospheric contributions to the system temperature, thereby deriving forecasts applicable to scheduling radio observations for up to 10 days into the future. Additionally, the algorithms embedded in the data processing pipeline use historical values of the forecasted opacity to calibrate observations. Until recently, we have concentrated on predictions for high frequency (> 15 GHz) observing, as these need to be scheduled carefully around bad weather. We have been using simple models for the contribution of rain and clouds since we only schedule low-frequency observations under these conditions. In this project, we wanted to improve the scheduling of the GBT and data calibration at low frequencies by deriving better algorithms for clouds and rain. To address the limitation at low frequency, the observatory acquired a Radiometrics Corporation MP-1500A radiometer, which operates in 27 channels between 22 and 30 GHz. By comparing 16 months of measurements from the radiometer against forecasted system temperatures, we have confirmed that forecasted system temperatures are indistinguishable from those measured under good weather conditions. Small miss-calibrations of the radiometer data dominate the comparison. By using recalibrated radiometer measurements, we looked at bad weather days to derive better models for forecasting the

  9. Automated and dynamic scheduling for geodetic VLBI - A simulation study for AuScope and global networks

    Science.gov (United States)

    Iles, E. J.; McCallum, L.; Lovell, J. E. J.; McCallum, J. N.

    2018-02-01

    As we move into the next era of geodetic VLBI, the scheduling process is one focus for improvement in terms of increased flexibility and the ability to react with changing conditions. A range of simulations were conducted to ascertain the impact of scheduling on geodetic results such as Earth Orientation Parameters (EOPs) and station coordinates. The potential capabilities of new automated scheduling modes were also simulated, using the so-called 'dynamic scheduling' technique. The primary aim was to improve efficiency for both cost and time without losing geodetic precision, particularly to maximise the uses of the Australian AuScope VLBI array. We show that short breaks in observation will not significantly degrade the results of a typical 24 h experiment, whereas simply shortening observing time degrades precision exponentially. We also confirm the new automated, dynamic scheduling mode is capable of producing the same standard of result as a traditional schedule, with close to real-time flexibility. Further, it is possible to use the dynamic scheduler to augment the 3 station Australian AuScope array and thereby attain EOPs of the current global precision with only intermittent contribution from 2 additional stations. We thus confirm automated, dynamic scheduling bears great potential for flexibility and automation in line with aims for future continuous VLBI operations.

  10. Rework Impacts Evaluation Through System Dynamics Approach in Overlapped Product Development Schedule

    Directory of Open Access Journals (Sweden)

    Lino Guimarães Marujo

    2009-07-01

    Full Text Available This work aims to explore a novel framework to analyze the planning concepts in product development projects employing techniques to reduce the lead-time of activities, such as overlapping of a pair of each. With the System Dynamics methodology a model to evaluate the rework fraction needed to accommodate the deviations proportional to the overlapping grade of the activities. A numerical example is provided to demonstrate the validity of the model. Although problems encountered during the project management are dynamic, they have been treated on a static basis, what has as result, chronic schedules delays, overruns and cost overspent persist in follow the managers’ (reactions. In this work, we have addressed this known problem by introducing and reviewing some characteristics of the concept of rework in overlapped schedules. This consists in observe and capture the relations feedbacks among the original planned project schedule, the overlapping strategy and the inherent uncertainty in a work being done with poor information. To realize this concept, we have faced with many behaviors patterns (e.g. rework, new duration, non-conformity, and analyze the output behavior pattern, produced by the proposed model.

  11. Online Dynamic Balance Technology for High Speed Spindle Based on Gain Parameter Adaption and Scheduling Control

    Directory of Open Access Journals (Sweden)

    Shihai Zhang

    2018-06-01

    Full Text Available Unbalance vibration is one of the main vibration forms of a high speed machine tool spindle. The overlarge unbalance vibration will have some adverse effects on the working life of the spindle system and the surface quality of the work-piece. In order to reduce the unbalance of a high speed spindle system, a pneumatic online dynamic balance device and its control system are presented in the paper. To improve the balance accuracy and adaptation of the balance system, the gain parameter adaption and scheduling control method are proposed first, and then the different balance effects of the influence coefficient method and the gain scheduling control method are compared through many dynamic balance experiments of the high speed spindle. The experimental results indicate that the gain parameters can be changed timely according to the transformation of the speed and kinetic parameters of the spindle system. The balance accuracy can be improved for a high speed spindle with time-varying characteristics, based on the adaptive gain scheduling control method.

  12. Simulation-Based Dynamic Passenger Flow Assignment Modelling for a Schedule-Based Transit Network

    Directory of Open Access Journals (Sweden)

    Xiangming Yao

    2017-01-01

    Full Text Available The online operation management and the offline policy evaluation in complex transit networks require an effective dynamic traffic assignment (DTA method that can capture the temporal-spatial nature of traffic flows. The objective of this work is to propose a simulation-based dynamic passenger assignment framework and models for such applications in the context of schedule-based rail transit systems. In the simulation framework, travellers are regarded as individual agents who are able to obtain complete information on the current traffic conditions. A combined route selection model integrated with pretrip route selection and entrip route switch is established for achieving the dynamic network flow equilibrium status. The train agent is operated strictly with the timetable and its capacity limitation is considered. A continuous time-driven simulator based on the proposed framework and models is developed, whose performance is illustrated through a large-scale network of Beijing subway. The results indicate that more than 0.8 million individual passengers and thousands of trains can be simulated simultaneously at a speed ten times faster than real time. This study provides an efficient approach to analyze the dynamic demand-supply relationship for large schedule-based transit networks.

  13. A Dynamic Resource Scheduling Method Based on Fuzzy Control Theory in Cloud Environment

    Directory of Open Access Journals (Sweden)

    Zhijia Chen

    2015-01-01

    Full Text Available The resources in cloud environment have features such as large-scale, diversity, and heterogeneity. Moreover, the user requirements for cloud computing resources are commonly characterized by uncertainty and imprecision. Hereby, to improve the quality of cloud computing service, not merely should the traditional standards such as cost and bandwidth be satisfied, but also particular emphasis should be laid on some extended standards such as system friendliness. This paper proposes a dynamic resource scheduling method based on fuzzy control theory. Firstly, the resource requirements prediction model is established. Then the relationships between resource availability and the resource requirements are concluded. Afterwards fuzzy control theory is adopted to realize a friendly match between user needs and resources availability. Results show that this approach improves the resources scheduling efficiency and the quality of service (QoS of cloud computing.

  14. Dynamic workload balancing of parallel applications with user-level scheduling on the Grid

    CERN Document Server

    Korkhov, Vladimir V; Krzhizhanovskaya, Valeria V

    2009-01-01

    This paper suggests a hybrid resource management approach for efficient parallel distributed computing on the Grid. It operates on both application and system levels, combining user-level job scheduling with dynamic workload balancing algorithm that automatically adapts a parallel application to the heterogeneous resources, based on the actual resource parameters and estimated requirements of the application. The hybrid environment and the algorithm for automated load balancing are described, the influence of resource heterogeneity level is measured, and the speedup achieved with this technique is demonstrated for different types of applications and resources.

  15. Dynamic Sleep Scheduling on Air Pollution Levels Monitoring with Wireless Sensor Network

    OpenAIRE

    Gezaq Abror; Rusminto Tjatur Widodo; M. Udin Harun Al Rasyid

    2018-01-01

    Wireless Sensor Network (WSN) can be applied for Air Pollution Level Monitoring System that have been determined by the Environmental Impact Management Agency which is  PM10, SO2, O3, NO2 and CO. In WSN, node system is constrained to a limited power supply, so that the node system has a lifetime. To doing lifetime maximization, power management scheme is required and sensor nodes should use energy efficiently. This paper proposes dynamic sleep scheduling using Time Category-Fuzzy Logic (Time-...

  16. Automatic programming via iterated local search for dynamic job shop scheduling.

    Science.gov (United States)

    Nguyen, Su; Zhang, Mengjie; Johnston, Mark; Tan, Kay Chen

    2015-01-01

    Dispatching rules have been commonly used in practice for making sequencing and scheduling decisions. Due to specific characteristics of each manufacturing system, there is no universal dispatching rule that can dominate in all situations. Therefore, it is important to design specialized dispatching rules to enhance the scheduling performance for each manufacturing environment. Evolutionary computation approaches such as tree-based genetic programming (TGP) and gene expression programming (GEP) have been proposed to facilitate the design task through automatic design of dispatching rules. However, these methods are still limited by their high computational cost and low exploitation ability. To overcome this problem, we develop a new approach to automatic programming via iterated local search (APRILS) for dynamic job shop scheduling. The key idea of APRILS is to perform multiple local searches started with programs modified from the best obtained programs so far. The experiments show that APRILS outperforms TGP and GEP in most simulation scenarios in terms of effectiveness and efficiency. The analysis also shows that programs generated by APRILS are more compact than those obtained by genetic programming. An investigation of the behavior of APRILS suggests that the good performance of APRILS comes from the balance between exploration and exploitation in its search mechanism.

  17. Action dependent heuristic dynamic programming based residential energy scheduling with home energy inter-exchange

    International Nuclear Information System (INIS)

    Xu, Yancai; Liu, Derong; Wei, Qinglai

    2015-01-01

    Highlights: • The algorithm is developed in the two-household energy management environment. • We develop the absent energy penalty cost for the first time. • The algorithm has ability to keep adapting in real-time operations. • Its application can lower total costs and achieve better load balancing. - Abstract: Residential energy scheduling is a hot topic nowadays in the background of energy saving and environmental protection worldwide. To achieve this objective, a new residential energy scheduling algorithm is developed for energy management, based on action dependent heuristic dynamic programming. The algorithm works under the circumstance of residential real-time pricing and two adjacent housing units with energy inter-exchange, which can reduce the overall cost and enhance renewable energy efficiency after long-term operation. It is designed to obtain the optimal control policy to manage the directions and amounts of electricity energy flux. The algorithm’s architecture is mainly constructed based on neural networks, denoting the learned characteristics in the linkage of layers. To get close to real situations, many constraints such as maximum charging/discharging power of batteries are taken into account. The absent energy penalty cost is developed for the first time as a part of the performance index function. When the environment changes, the residential energy scheduling algorithm gains new features and keeps adapting in real-time operations. Simulation results show that the developed algorithm is beneficial to energy conversation

  18. A MODIFIED GIFFLER AND THOMPSON ALGORITHM COMBINED WITH DYNAMIC SLACK TIME FOR SOLVING DYNAMIC SCHEDULE PROBLEMS

    Directory of Open Access Journals (Sweden)

    Tanti Octavia

    2003-01-01

    Full Text Available A Modified Giffler and Thompson algorithm combined with dynamic slack time is used to allocate machines resources in dynamic nature. It was compared with a Real Time Order Promising (RTP algorithm. The performance of modified Giffler and Thompson and RTP algorithms are measured by mean tardiness. The result shows that modified Giffler and Thompson algorithm combined with dynamic slack time provides significantly better result compared with RTP algorithm in terms of mean tardiness.

  19. Food irradiation and airline catering

    International Nuclear Information System (INIS)

    Preston, F.S.

    1988-01-01

    Food poisoning from contaminated airline food can produce serious consequences for airline crew and passengers and can hazard flight. While irradiation of certain foodstuffs has been practised in a number of countries for some years, application of the process has not been made to complete meals. This paper considers the advantages, technical considerations, costs and possible application to airline meals. In addition, the need to educate the public in the advantages of the process in the wake of incidents such as Chernobyl is discussed

  20. Food irradiation and airline catering.

    Science.gov (United States)

    Preston, F S

    1988-04-01

    Food poisoning from contaminated airline food can produce serious consequences for airline crew and passengers and can hazard flight. While irradiation of certain foodstuffs has been practised in a number of countries for some years, application of the process has not been made to complete meals. This paper considers the advantages, technical considerations, costs and possible application to airline meals. In addition, the need to educate the public in the advantages of the process in the wake of incidents such as Chernobyl is discussed.

  1. Food irradiation and airline catering

    Energy Technology Data Exchange (ETDEWEB)

    Preston, F.S.

    1988-04-01

    Food poisoning from contaminated airline food can produce serious consequences for airline crew and passengers and can hazard flight. While irradiation of certain foodstuffs has been practised in a number of countries for some years, application of the process has not been made to complete meals. This paper considers the advantages, technical considerations, costs and possible application to airline meals. In addition, the need to educate the public in the advantages of the process in the wake of incidents such as Chernobyl is discussed.

  2. Business Model Innovation in Airlines

    Directory of Open Access Journals (Sweden)

    Bruno Alencar Pereira

    2017-03-01

    Full Text Available The business models innovation in airlines can contribute to the creation of value, competitive advantage and profitability with new possibilities of action. The proposed paper aimed to identify the business models adopted by airlines and identify how the innovation occurs at these organizations. The methodology adopted is characterized as empirical, exploratory and descriptive research by multiple case study with three major Brazilian airlines. The results demonstrate that the search for paradigm breaks, related to the dichotomic traditional models of low-cost and full-service, toward hybrid business models occur linearly, as examples highlighted by companies, in which internal changes in business models are considered major organizational innovations.

  3. Drivers of airline loyalty : evidence from the business travelers in China.

    OpenAIRE

    Vlachos, I.; Lin, Z.

    2014-01-01

    This paper examines the key factors that determine business traveler loyalty toward full-service airlines in China. Based on literature review and panel interview, ten airline attributes under three categories were derived: (a) operational factors: safety, punctuality, and aircraft; (b) competitive factors: frequency of flights, schedule, frequent flyer program, ticket price, and reputation; and (c) attractive factors: in flight food & drinks and in flight staff service. We surveyed 2000 Chin...

  4. New scheduling rules for a dynamic flexible flow line problem with sequence-dependent setup times

    Science.gov (United States)

    Kia, Hamidreza; Ghodsypour, Seyed Hassan; Davoudpour, Hamid

    2017-09-01

    In the literature, the application of multi-objective dynamic scheduling problem and simple priority rules are widely studied. Although these rules are not efficient enough due to simplicity and lack of general insight, composite dispatching rules have a very suitable performance because they result from experiments. In this paper, a dynamic flexible flow line problem with sequence-dependent setup times is studied. The objective of the problem is minimization of mean flow time and mean tardiness. A 0-1 mixed integer model of the problem is formulated. Since the problem is NP-hard, four new composite dispatching rules are proposed to solve it by applying genetic programming framework and choosing proper operators. Furthermore, a discrete-event simulation model is made to examine the performances of scheduling rules considering four new heuristic rules and the six adapted heuristic rules from the literature. It is clear from the experimental results that composite dispatching rules that are formed from genetic programming have a better performance in minimization of mean flow time and mean tardiness than others.

  5. A QoS-Based Dynamic Queue Length Scheduling Algorithm in Multiantenna Heterogeneous Systems

    Directory of Open Access Journals (Sweden)

    Verikoukis Christos

    2010-01-01

    Full Text Available The use of real-time delay-sensitive applications in wireless systems has significantly grown during the last years. Therefore the designers of wireless systems have faced a challenging issue to guarantee the required Quality of Service (QoS. On the other hand, the recent advances and the extensive use of multiple antennas have already been included in several commercial standards, where the multibeam opportunistic transmission beamforming strategies have been proposed to improve the performance of the wireless systems. A cross-layer-based dynamically tuned queue length scheduler is presented in this paper, for the Downlink of multiuser and multiantenna WLAN systems with heterogeneous traffic requirements. To align with modern wireless systems transmission strategies, an opportunistic scheduling algorithm is employed, while a priority to the different traffic classes is applied. A tradeoff between the maximization of the throughput of the system and the guarantee of the maximum allowed delay is obtained. Therefore, the length of the queue is dynamically adjusted to select the appropriate conditions based on the operator requirements.

  6. The study of customer relationship management in Thai airline industry: A case of Thai travelers in Thailand

    Directory of Open Access Journals (Sweden)

    Colin Law

    2017-02-01

    Full Text Available Purpose: This paper offer marketing strategy suggestion to the airlines operating within the Thai aviation market. It identifies the recommended motivational factors that influence the airline customers’ decision to their airline choices. Airlines use different customer relationship management programs to attract returning customers.  This paper suggested the most attractive motivation factors for Thailand's air travel market. Design/methodology/approach: This research paper is an attempt to study and identify the factors, including loyalty program, distribution channel, customer services, promotions and other influence causes that affected the customer preference in the airline ticket purchasing behavior in Thailand. A questionnaire survey was conducted with the sample identified through unrestricted non probability sampling technique at four major airports in Thailand. The data collected are analyzed to identify the favorable drivers that lead to customer decision on airline choice. Findings: The result from the study has demonstrated that price, and promotion has a significant impact on customer preference and positively leads to repurchase intention for their future travel. Moreover, flight schedules are also a main factor influencing the travelers’ final decision on airline choice. However, when the promotional strategies and schedule are comparable between airlines, customers are attracted by the airline amenities and services. Loyalty program (frequent-flier program flier program is showing a less attractive motivator while distribution channel demonstrates the least important affecting the travelers’ choice of airline. Originality/value: The paper begins with an overview of previous research in the area of airlines customer relationship management and then moves on to what is currently being implemented by the airlines. The authors then propose several customer relationship strategies and identify the most attractive one that

  7. Outsourcing as an Airline Strategy

    Science.gov (United States)

    Rutner, Stephen M.; Brown, John H.

    1999-01-01

    Since the deregulation of the airline industry, carriers have searched for any method to improve their competitive position. At the same time, there has been a growth in the use of Third Party Logistics throughout corporate America. This paper presents an overview of the Third Party Logistics system of outsourcing and insourcing within the airline industry. This discussion generated a number of propositions, possible future scenarios and opportunities for empirical testing.

  8. Dietary Advice for Airline Travel.

    Science.gov (United States)

    Leggat; Nowak

    1997-03-01

    In addition to their regular meal service, most of the major domestic and international airlines offer special meals. It should be noted that regular meal services on international flights often give a choice of meals, even in economy class, and often include a salad and or fruit dish, which could be consumed by most people. More airlines also seem to be moving towards having at least one more culturally appropriate meal on the menu, particularly for relevant flight sectors. However, these meals may be inappropriate for some passengers, and there is a need for this special meals service. Meals services on airlines have improved greatly in recent years, particularly with the employment of consultant dietitians to the catering staff of airlines and advances in chef training. Special meal services are designed to cater to the most common variations of meals required by most passengers for medical, religious, or other reasons. The special requirements for these meals are described elsewhere.1 It is important to realize that the meals are designed and the ingredients interpreted by that airline, and may not necessarily reflect what the traveler might eat at home. So it is important to advise travelers not to have high expectations of this special meal service. This paper aims to provide some basic practical advice for selection of special diets for airline travelers.

  9. Environmental charges in airline markets

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Fredrik [Goeteborg Univ., Dept. of Economics, Goeteborg (Sweden)

    2002-07-01

    Over the last two decades many airline markets have been deregulated, resulting in increased competition and use of different types of networks. At the same time there has been an intense discussion on environmental taxation of airline traffic. It is likely that an optimal environmental charge and the effects of a charge differ between different types of aviation markets. In this paper, we derive optimal flight (environmental) charges for different types of airline markets. The first type of market is a multiproduct monopoly airline operating either a point-to-point network or a hub-and-spoke network. The optimal charge is shown to be similar in construction to an optimal charge for a monopolist. We also compare the environmental impact of the two types of networks. Given no differences in marginal damages between airports we find that an airline will always choose the network with the highest environmental damages. The second type of market we investigate is a multiproduct duopoly, where two airlines compete in both passengers and flights. The formulation of the optimal charge is similar to the optimal charge of a single product oligopoly. However, we also show that it is, because of strategic effects, difficult to determine the effects of the charge on the number of flights. (Author)

  10. Ant colony optimization and event-based dynamic task scheduling and staffing for software projects

    Science.gov (United States)

    Ellappan, Vijayan; Ashwini, J.

    2017-11-01

    In programming change organizations from medium to inconceivable scale broadens, the issue of wander orchestrating is amazingly unusual and testing undertaking despite considering it a manual system. Programming wander-organizing requirements to deal with the issue of undertaking arranging and in addition the issue of human resource portion (also called staffing) in light of the way that most of the advantages in programming ventures are individuals. We propose a machine learning approach with finds respond in due order regarding booking by taking in the present arranging courses of action and an event based scheduler revives the endeavour arranging system moulded by the learning computation in perspective of the conformity in event like the begin with the Ander, the instant at what time possessions be free starting to ended errands, and the time when delegates stick together otherwise depart the wander inside the item change plan. The route toward invigorating the timetable structure by the even based scheduler makes the arranging method dynamic. It uses structure components to exhibit the interrelated surges of endeavours, slip-ups and singular all through different progression organizes and is adjusted to mechanical data. It increases past programming wander movement ask about by taking a gander at a survey based process with a one of a kind model, organizing it with the data based system for peril assessment and cost estimation, and using a choice showing stage.

  11. The effect of dynamic scheduling and routing in a solid waste management system

    International Nuclear Information System (INIS)

    Johansson, Ola M.

    2006-01-01

    Solid waste collection and hauling account for the greater part of the total cost in modern solid waste management systems. In a recent initiative, 3300 Swedish recycling containers have been fitted with level sensors and wireless communication equipment, thereby giving waste collection operators access to real-time information on the status of each container. In this study, analytical modeling and discrete-event simulation have been used to evaluate different scheduling and routing policies utilizing the real-time data. In addition to the general models developed, an empirical simulation study has been performed on the downtown recycling station system in Malmoe, Sweden. From the study, it can be concluded that dynamic scheduling and routing policies exist that have lower operating costs, shorter collection and hauling distances, and reduced labor hours compared to the static policy with fixed routes and pre-determined pick-up frequencies employed by many waste collection operators today. The results of the analytical model and the simulation models are coherent, and consistent with experiences of the waste collection operators

  12. Operating cost model for local service airlines

    Science.gov (United States)

    Anderson, J. L.; Andrastek, D. A.

    1976-01-01

    Several mathematical models now exist which determine the operating economics for a United States trunk airline. These models are valuable in assessing the impact of new aircraft into an airline's fleet. The use of a trunk airline cost model for the local service airline does not result in representative operating costs. A new model is presented which is representative of the operating conditions and resultant costs for the local service airline. The calculated annual direct and indirect operating costs for two multiequipment airlines are compared with their actual operating experience.

  13. Handling machine breakdown for dynamic scheduling by a colony of cognitive agents in a holonic manufacturing framework

    Directory of Open Access Journals (Sweden)

    T. K. Jana

    2015-09-01

    Full Text Available There is an ever increasing need of providing quick, yet improved solution to dynamic scheduling by better responsiveness following simple coordination mechanism to better adapt to the changing environments. In this endeavor, a cognitive agent based approach is proposed to deal with machine failure. A Multi Agent based Holonic Adaptive Scheduling (MAHoAS architecture is developed to frame the schedule by explicit communication between the product holons and the resource holons in association with the integrated process planning and scheduling (IPPS holon under normal situation. In the event of breakdown of a resource, the cooperation is sought by implicit communication. Inspired by the cognitive behavior of human being, a cognitive decision making scheme is proposed that reallocates the incomplete task to another resource in the most optimized manner and tries to expedite the processing in view of machine failure. A metamorphic algorithm is developed and implemented in Oracle 9i to identify the best candidate resource for task re-allocation. Integrated approach to process planning and scheduling realized under Multi Agent System (MAS framework facilitates dynamic scheduling with improved performance under such situations. The responsiveness of the resources having cognitive capabilities helps to overcome the adverse consequences of resource failure in a better way.

  14. QoS Differential Scheduling in Cognitive-Radio-Based Smart Grid Networks: An Adaptive Dynamic Programming Approach.

    Science.gov (United States)

    Yu, Rong; Zhong, Weifeng; Xie, Shengli; Zhang, Yan; Zhang, Yun

    2016-02-01

    As the next-generation power grid, smart grid will be integrated with a variety of novel communication technologies to support the explosive data traffic and the diverse requirements of quality of service (QoS). Cognitive radio (CR), which has the favorable ability to improve the spectrum utilization, provides an efficient and reliable solution for smart grid communications networks. In this paper, we study the QoS differential scheduling problem in the CR-based smart grid communications networks. The scheduler is responsible for managing the spectrum resources and arranging the data transmissions of smart grid users (SGUs). To guarantee the differential QoS, the SGUs are assigned to have different priorities according to their roles and their current situations in the smart grid. Based on the QoS-aware priority policy, the scheduler adjusts the channels allocation to minimize the transmission delay of SGUs. The entire transmission scheduling problem is formulated as a semi-Markov decision process and solved by the methodology of adaptive dynamic programming. A heuristic dynamic programming (HDP) architecture is established for the scheduling problem. By the online network training, the HDP can learn from the activities of primary users and SGUs, and adjust the scheduling decision to achieve the purpose of transmission delay minimization. Simulation results illustrate that the proposed priority policy ensures the low transmission delay of high priority SGUs. In addition, the emergency data transmission delay is also reduced to a significantly low level, guaranteeing the differential QoS in smart grid.

  15. Airline travel since 9/11

    Science.gov (United States)

    2005-12-01

    Airline capacity (expressed in available seats) has : increased more slowly than the increase in airline passenger : travel. : Low-cost carriers represent a growing portion of the : domestic aviation market. This change has been accompanied :...

  16. Risk-constrained dynamic self-scheduling of a pumped-storage plant in the energy and ancillary service markets

    International Nuclear Information System (INIS)

    Kazempour, S. Jalal; Moghaddam, M. Parsa; Haghifam, M.R.; Yousefi, G.R.

    2009-01-01

    This work addresses a new framework for self-scheduling of an individual price-taker pumped-storage plant in a day-ahead (DA) market. The goal is achieving the best trade-off between the expected profit and the risks when the plant participates in DA energy, spinning reserve and regulation markets. In this paper, a set of uncertainties including price forecasting errors and also the uncertainty of power delivery requests in the ancillary service markets are contemplated. Considering these uncertainties, a new approach is proposed which is called dynamic self-scheduling (DSS). This risk-constrained dynamic self-scheduling problem is therefore formulated and solved as a mixed integer programming (MIP) problem. Numerical results for a case study are discussed. (author)

  17. Cardiovascular Risk Factors in Airline Pilots.

    Science.gov (United States)

    Lord, Dana; Conlon, Helen Acree

    2018-02-01

    The health of an airline pilot is imperative to the safe travels of millions of people worldwide. Medical providers evaluate the cardiovascular risks for airline pilots and the medical requirements to obtain and maintain licensure as an airline pilot. It is the role of the occupational health nurse practitioner to evaluate and reduce the risk of cardiovascular disease in this population.

  18. Southwest Airlines: lessons in loyalty.

    Science.gov (United States)

    D'Aurizio, Patricia

    2008-01-01

    Southwest Airlines continues to garner accolades in the areas of customer service, workforce management, and profitability. Since both the health care and airlines industries deal with a service rather than a product, the customer experience depends on the people who deliver that experience. Employees' commitment or "loyalty" to their customers, their employer, and their work translates into millions of dollars of revenue. What employee wants to work for "the worst employer in town?" Nine loyalty lessons from Southwest can be carried over to the health care setting for the benefit of employees and patients.

  19. NASA Airline Operations Research Center

    Science.gov (United States)

    Mogford, Richard H.

    2016-01-01

    This is a PowerPoint presentation NASA airline operations center (AOC) research. It includes information on using IBM Watson in the AOC. It also reviews a dispatcher decision support tool call the Flight Awareness Collaboration Tool (FACT). FACT gathers information about winter weather onto one screen and includes predictive abilities. It should prove to be useful for airline dispatchers and airport personnel when they manage winter storms and their effect on air traffic. This material is very similar to other previously approved presentations with the same title.

  20. Pre-emptive resource-constrained multimode project scheduling using genetic algorithm: A dynamic forward approach

    Directory of Open Access Journals (Sweden)

    Aidin Delgoshaei

    2016-09-01

    Full Text Available Purpose: The issue resource over-allocating is a big concern for project engineers in the process of scheduling project activities. Resource over-allocating drawback is frequently seen after scheduling of a project in practice which causes a schedule to be useless. Modifying an over-allocated schedule is very complicated and needs a lot of efforts and time. In this paper, a new and fast tracking method is proposed to schedule large scale projects which can help project engineers to schedule the project rapidly and with more confidence. Design/methodology/approach: In this article, a forward approach for maximizing net present value (NPV in multi-mode resource constrained project scheduling problem while assuming discounted positive cash flows (MRCPSP-DCF is proposed. The progress payment method is used and all resources are considered as pre-emptible. The proposed approach maximizes NPV using unscheduled resources through resource calendar in forward mode. For this purpose, a Genetic Algorithm is applied to solve. Findings: The findings show that the proposed method is an effective way to maximize NPV in MRCPSP-DCF problems while activity splitting is allowed. The proposed algorithm is very fast and can schedule experimental cases with 1000 variables and 100 resources in few seconds. The results are then compared with branch and bound method and simulated annealing algorithm and it is found the proposed genetic algorithm can provide results with better quality. Then algorithm is then applied for scheduling a hospital in practice. Originality/value: The method can be used alone or as a macro in Microsoft Office Project® Software to schedule MRCPSP-DCF problems or to modify resource over-allocated activities after scheduling a project. This can help project engineers to schedule project activities rapidly with more accuracy in practice.

  1. Dynamical Scheduling and Robust Control in Uncertain Environments with Petri Nets for DESs

    Directory of Open Access Journals (Sweden)

    Dimitri Lefebvre

    2017-10-01

    Full Text Available This paper is about the incremental computation of control sequences for discrete event systems in uncertain environments where uncontrollable events may occur. Timed Petri nets are used for this purpose. The aim is to drive the marking of the net from an initial value to a reference one, in minimal or near-minimal time, by avoiding forbidden markings, deadlocks, and dead branches. The approach is similar to model predictive control with a finite set of control actions. At each step only a small area of the reachability graph is explored: this leads to a reasonable computational complexity. The robustness of the resulting trajectory is also evaluated according to a risk probability. A sufficient condition is provided to compute robust trajectories. The proposed results are applicable to a large class of discrete event systems, in particular in the domains of flexible manufacturing. However, they are also applicable to other domains as communication, computer science, transportation, and traffic as long as the considered systems admit Petri Nets (PNs models. They are suitable for dynamical deadlock-free scheduling and reconfiguration problems in uncertain environments.

  2. An exact model for airline flight network optimization based on transport momentum and aircraft load factor

    Directory of Open Access Journals (Sweden)

    Daniel Jorge Caetano

    2017-12-01

    Full Text Available The problem of airline flight network optimization can be split into subproblems such as Schedule Generation (SG and Fleet Assignment (FA, solved in consecutive steps or in an integrated way, usually based on monetary costs and revenue forecasts. A linear pro­gramming model to solve SG and FA in an integrated way is presented, but with an al­ternative approach based on transport momentum and aircraft load factor. This alterna­tive approach relies on demand forecast and allows obtaining solutions considering min­imum average load factors. Results of the proposed model applications to instances of a regional Brazilian airline are presented. The comparison of the schedules generated by the proposed approach against those obtained by applying a model based on mone­tary costs and revenue forecasts demonstrates the validity of this alternative approach for airlines network planning.

  3. Multi-objective Mobile Robot Scheduling Problem with Dynamic Time Windows

    DEFF Research Database (Denmark)

    Dang, Vinh Quang; Nielsen, Izabela Ewa; Steger-Jensen, Kenn

    2012-01-01

    This paper deals with the problem of scheduling feeding tasks of a single mobile robot which has capability of supplying parts to feeders on pro-duction lines. The performance criterion is to minimize the total traveling time of the robot and the total tardiness of the feeding tasks being scheduled...

  4. Nonstandard Work Schedules, Family Dynamics, and Mother-Child Interactions During Early Childhood.

    Science.gov (United States)

    Prickett, Kate C

    2018-03-01

    The rising number of parents who work nonstandard schedules has led to a growing body of research concerned with what this trend means for children. The negative outcomes for children of parents who work nonstandard schedules are thought to arise from the disruptions these schedules place on family life, and thus, the types of parenting that support their children's development, particularly when children are young. Using a nationally representative sample of two-parent families (Early Childhood Longitudinal Study-Birth cohort, n = 3,650), this study examined whether mothers' and their partners' nonstandard work schedules were associated with mothers' parenting when children were 2 and 4 years old. Structural equation models revealed that mothers' and their partners' nonstandard work schedules were associated with mothers' lower scores on measures of positive and involved parenting. These associations were mediated by fathers' lower levels of participation in cognitively supportive parenting and greater imbalance in cognitively supportive tasks conducted by mothers versus fathers.

  5. 基于ISM的动态优先级调度算法%Dynamic Priority Schedule Algorithm Based on ISM

    Institute of Scientific and Technical Information of China (English)

    余祖峰; 蔡启先; 刘明

    2011-01-01

    The EDF schedule algorithm, one of main real-time schedule algorithms of the embedded Linux operating system, can not solve the overload schedule.For this, the paper introduces SLAD algorithm and BACKSLASH algorithm, which have good performance of system load.According to thinking of ISM algorithm, it puts forward a kind of dynamic priority schedule algorithm.According to case of overloads within some time, the algorithm can adjust EDF algorithm and SLAD algorithm neatly, thus improves schedule efficiency of system in usual load and overload cases.Test results for real-time tasks Deadline Miss Ratio(DMR) show its improvement effect.%在嵌入式Linux操作系统的实时调度算法中,EDF调度算法不能解决负载过载问题.为此,引进对系统负载有着良好表现的SLAD算法和BACKSLASH算法.基于ISM算法思路,提出一种动态优先级调度算法.该算法能根据一段时间内负载过载的情况,灵活地调度EDF算法和SLAD算法,从面提高系统在正常负载和过载情况下的调度效率.对实时任务截止期错失率DMR指标的测试结果证明了其改进效果.

  6. Enhancement of a model for Large-scale Airline Network Planning Problems

    NARCIS (Netherlands)

    Kölker, K.; Lopes dos Santos, Bruno F.; Lütjens, K.

    2016-01-01

    The main focus of this study is to solve the network planning problem based on passenger decision criteria including the preferred departure time and travel time for a real-sized airline network. For this purpose, a model of the integrated network planning problem is formulated including scheduling

  7. THE EVALUATION OF WORKING CAPITAL IN AIRLINE COMPANIES WHICH PROCEED IN BIST

    Directory of Open Access Journals (Sweden)

    Selcuk Kendirli

    2016-03-01

    Full Text Available The working capital like cash and liquid assets runs the facilities and supports daily activities of firms. This kind of capital is essential to continuity of activities, increase of volume, maintain credibility, reduce impacts of risks and to overcome with extraordinary situation. The working capital management is very important for making profits from activities, especially for dynamic sectors like aviation. The aviation industry which airline companies operate is a very dynamic sector. In this sector working capital has to be managed very professionally and carefully by airline companies. This study aims to assess the airline companies’ working capital in terms of effectiveness. Airline companies which shares traded on BIST will be sample of this study.

  8. Scheduling Aircraft Landings under Constrained Position Shifting

    Science.gov (United States)

    Balakrishnan, Hamsa; Chandran, Bala

    2006-01-01

    Optimal scheduling of airport runway operations can play an important role in improving the safety and efficiency of the National Airspace System (NAS). Methods that compute the optimal landing sequence and landing times of aircraft must accommodate practical issues that affect the implementation of the schedule. One such practical consideration, known as Constrained Position Shifting (CPS), is the restriction that each aircraft must land within a pre-specified number of positions of its place in the First-Come-First-Served (FCFS) sequence. We consider the problem of scheduling landings of aircraft in a CPS environment in order to maximize runway throughput (minimize the completion time of the landing sequence), subject to operational constraints such as FAA-specified minimum inter-arrival spacing restrictions, precedence relationships among aircraft that arise either from airline preferences or air traffic control procedures that prevent overtaking, and time windows (representing possible control actions) during which each aircraft landing can occur. We present a Dynamic Programming-based approach that scales linearly in the number of aircraft, and describe our computational experience with a prototype implementation on realistic data for Denver International Airport.

  9. Airline Safety: A Comparative Analysis.

    Science.gov (United States)

    1987-01-01

    shrinking FAA inspector force handling a rapidly growing number of air carriers. These studies have always shown an improvement in airline safety in the...EhCLhEmohhhhhhhEoo EhhshhEEmhhhhE EhhEohhEshhhhE EhhhEEEohEohEE EohEEEmhshEmhE IEEE...mmmo 1-2. jI. Mi6 NEW - secuRily CLASSIFICATION OF THIS PAGE (When De

  10. Airline network structure in competitive market

    Directory of Open Access Journals (Sweden)

    Babić Danica D.

    2014-01-01

    Full Text Available Airline's network is the key element of its business strategy and selected network structure will not have influence only on the airline's costs but could gain some advantage in revenues, too. Network designing implies that an airline has to make decisions about markets that it will serve and how to serve those markets. Network choice raises the following questions for an airline: a what markets to serve, b how to serve selected markets, c what level of service to offer, d what are the benefits/cost of the that decisions and e what is the influence of the competition. We analyzed the existing airline business models and corresponding network structure. The paper highlights the relationship between the network structures and the airline business strategies. Using a simple model we examine the relationship between the network structure and service quality in deregulated market.

  11. Building Airline Passenger Loyalty Through an Understanding of Customer Value: A Relationship Segmentation of Airline Passengers

    OpenAIRE

    Leick, Ryan

    2007-01-01

    This thesis explores means of restoring profitability to the airline industry by cultivating intrinsically motivated brand loyalty between passengers and airlines in today’s fragile environment. The air transport industry is caught up in traditional transaction-based strategies. Airlines rely on archaic frequent flyer programs (FFPs) to maintain loyalty which deter customers from choosing alternative airlines by increasing the cost associated with switching. In contrast, oth...

  12. 75 FR 45562 - Enhancing Airline Passenger Protections

    Science.gov (United States)

    2010-08-03

    ...This action extends the comment period for an NPRM on enhancing airline passenger protections that was published in the Federal Register on June 8, 2010. The Department of Transportation is extending the period for interested persons to submit comments on this rulemaking from August 9, 2010, to September 23, 2010. This extension is a result of requests from a number of airline associations, one airport association, and two airlines to extend the comment period for the proposal.

  13. Determinants of Market Structure and the Airline Industry

    Science.gov (United States)

    Raduchel, W.

    1972-01-01

    The general economic determinants of market structure are outlined with special reference to the airline industry. Included are the following facets: absolute size of firms; distributions of firms by size; concentration; entry barriers; product and service differentiation; diversification; degrees of competition; vertical integration; market boundaries; and economies of scale. Also examined are the static and dynamic properties of market structure in terms of mergers, government policies, and economic growth conditions.

  14. Crying wolf? On the price discrimination of online airline tickets

    OpenAIRE

    Vissers, Thomas; Nikiforakis, Nick; Bielova, Nataliia; Joosen, Wouter

    2014-01-01

    International audience; Price discrimination refers to the practice of dynamically varying the prices of goods based on a customer's purchasing power and willingness to pay. In this paper, motivated by several anecdotal ac-counts, we report on a three-week experiment, conducted in search of price discrimination in airline tickets. Despite presenting the companies with multiple opportunities for discriminating us, and contrary to our expectations, we do not find any evidence for systematic pri...

  15. Mix-oriented manufacturing control (MOMC): a quasi-optimal procedure for dynamic scheduling control

    Science.gov (United States)

    Cristofari, Marco; Caron, Franco; McDuffie, Ernest L.

    1997-12-01

    The total system throughput (ST) is one of the most important decision variables at the planning/scheduling phase of a manufacturing system. Material requirement planning (MRP) and master production schedule (MPS) are based on the assumption that ST is known. All the subsequent developments (e.g. jobs- release, system work-load, input-product mix, etc.) depends on such an assumption. If this assumption is incorrect, the production activity control (PAC) will not be able to satisfy the planned targets during the scheduling phase. Delays and bottlenecks will be unavoidable in the system. In case of random flexible manufacturing system (FMS) (or, in general, job-shop production), the measure of ST can not be evaluated a priori without running simulations or observing the actual flow of the operations in the system. The way entities enter the system (sequencing and percentage of the input products) effects the value of ST in such a way that estimation based on historical data are highly risky. The methodology proposed in this paper allows the scheduler to assess the analytical functions which link ST, and other output performance variables, to the input product mix (IPM). This way the robustness of the scheduling plan can be verified before the actual release of the jobs into the system.

  16. A Comparative Facebook Content Analysis between Romanian and Western European Airline Carriers

    Directory of Open Access Journals (Sweden)

    Bogdan AVRAM

    2014-03-01

    Full Text Available This research aims to investigate the different social media strategies adopted by the airline companies from two European regions. In the attempt to land more customers on their social media runway, drive more sales from social media content, increase customer satisfaction through a high response rate or increase their brand awareness, the airlines combine creativity and high-quality ideas to better promote their products and services to customers all around the globe. The paper analyses the content (number of fans, posts, number of likes, the dynamics of comments, response rate on the Facebook pages of Tarom, Blue Air, Wizz Air, Lufthansa, Austrian Airlines, KLM International and Air Europa on a one week period (10th February – 18th February 2014 and successful practices on social media. The paper also aims to provide solutions for airlines to better connect with their passengers and effectively use the social media environment to increase sales and customer satisfaction.

  17. A Multi-layer Dynamic Model for Coordination Based Group Decision Making in Water Resource Allocation and Scheduling

    Science.gov (United States)

    Huang, Wei; Zhang, Xingnan; Li, Chenming; Wang, Jianying

    Management of group decision-making is an important issue in water source management development. In order to overcome the defects in lacking of effective communication and cooperation in the existing decision-making models, this paper proposes a multi-layer dynamic model for coordination in water resource allocation and scheduling based group decision making. By introducing the scheme-recognized cooperative satisfaction index and scheme-adjusted rationality index, the proposed model can solve the problem of poor convergence of multi-round decision-making process in water resource allocation and scheduling. Furthermore, the problem about coordination of limited resources-based group decision-making process can be solved based on the effectiveness of distance-based group of conflict resolution. The simulation results show that the proposed model has better convergence than the existing models.

  18. LOAD ADAPTIVE DYNAMIC SCHEDULING OF TASKS WITH HARD DEADLINES USEFUL FOR INDUSTRIAL APPLICATIONS

    NARCIS (Netherlands)

    HALANG, WA

    1992-01-01

    All intrinsic properties of the earliest deadline task scheduling discipline are compiled and discussed in order to show that this is the most advantageous scheme at hand, characterised by efficiency and allowing predictable system behaviour. It is then pointed out how the method naturally extends

  19. On the Runtime of Randomized Local Search and Simple Evolutionary Algorithms for Dynamic Makespan Scheduling

    DEFF Research Database (Denmark)

    Neumann, Frank; Witt, Carsten

    2015-01-01

    combinatorial optimization problem, namely makespan scheduling. We study the model of a strong adversary which is allowed to change one job at regular intervals. Furthermore, we investigate the setting of random changes. Our results show that randomized local search and a simple evolutionary algorithm are very...

  20. The Operational Performance of UK Airlines

    DEFF Research Database (Denmark)

    Assaf, A. Georg; Josiassen, Alexander

    2011-01-01

    Purpose – The purpose of this paper is to measure the efficiency of UK airlines in light of all the recent industry challenges. Design/methodology/approach – The study measured the technical efficiency of airlines through the innovative data envelopment analysis (DEA) bootstrap methodology. Findi...

  1. Consumer Marketing and the Airline Industry

    Science.gov (United States)

    Roy, W. R.

    1972-01-01

    The fundamentals of consumer marketing as applied to the airline industry are considered. An attempt is made to boil down the mystique and jargon which frequently surround the subject of marketing. Topics covered include: (1) The marketing concept; (2) consumer expectations from airlines; (3) planning of marketing strategy; and (4) the roles of advertising, sales, and middlemen.

  2. The spatial scope of airline competition

    NARCIS (Netherlands)

    Lijesen, M.G.; Behrens, C.L.

    2017-01-01

    We investigate whether alternative city- or airport pairs are viable substitutes and the extent to which they impact airline competition between the United Kingdom and continental Europe. To this end, we employ and measure airlines’ best responses in equilibrium. Using monthly airline-route seat

  3. Airline Careers. Aviation Careers Series. Revised.

    Science.gov (United States)

    Zaharevitz, Walter

    This booklet, one in a series on aviation careers, outlines the variety of careers available in airlines. The first part of the booklet provides general information about careers in the airline industry, including salaries, working conditions, job requirements, and projected job opportunities. In the main part of the booklet, the following 22 job…

  4. Overseas airlines woo Chinese tourists

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> A well-known ancient Chinese poet, Su Shi (1037-1101), used to describe the natural scene in April as: "Two or three sprays of peach behind bamboo; When spring warms the river the ducks are the first to know."As for the potential of China’s tourism industry, airline companies from other countries seem to be the "ducks" who have very good foresight about passenger loads as more Chinese travellers prefer overseas destinations as their first choice for holidays, especially the three week-long holidays, Spring Festival, May Day and National Day.As the May Day holiday approaches,

  5. Fuel conservation: the airline - ATC

    Energy Technology Data Exchange (ETDEWEB)

    Grundy, P.M.

    1982-05-01

    The air traffic control system has a greater impact on fuel conservation than any other factor in aviation, the most energy intensive industry in the world. The article discusses various measures that could be adopted by airlines and air traffic controllers to increase fuel conservation. These include: reducing operating empty weights, flying at optimum altitude, direct routing, linear holding, speed control, flight planning, loading for favorable center of gravity to reduce trim drag, minimizing route mileage, and clearance priorities for more fuel demanding aircraft during landing.

  6. Formulation and demonstration of a robust mean variance optimization approach for concurrent airline network and aircraft design

    Science.gov (United States)

    Davendralingam, Navindran

    Conceptual design of aircraft and the airline network (routes) on which aircraft fly on are inextricably linked to passenger driven demand. Many factors influence passenger demand for various Origin-Destination (O-D) city pairs including demographics, geographic location, seasonality, socio-economic factors and naturally, the operations of directly competing airlines. The expansion of airline operations involves the identificaion of appropriate aircraft to meet projected future demand. The decisions made in incorporating and subsequently allocating these new aircraft to serve air travel demand affects the inherent risk and profit potential as predicted through the airline revenue management systems. Competition between airlines then translates to latent passenger observations of the routes served between OD pairs and ticket pricing---this in effect reflexively drives future states of demand. This thesis addresses the integrated nature of aircraft design, airline operations and passenger demand, in order to maximize future expected profits as new aircraft are brought into service. The goal of this research is to develop an approach that utilizes aircraft design, airline network design and passenger demand as a unified framework to provide better integrated design solutions in order to maximize expexted profits of an airline. This is investigated through two approaches. The first is a static model that poses the concurrent engineering paradigm above as an investment portfolio problem. Modern financial portfolio optimization techniques are used to leverage risk of serving future projected demand using a 'yet to be introduced' aircraft against potentially generated future profits. Robust optimization methodologies are incorporated to mitigate model sensitivity and address estimation risks associated with such optimization techniques. The second extends the portfolio approach to include dynamic effects of an airline's operations. A dynamic programming approach is

  7. Electromagnetic interference-aware transmission scheduling and power control for dynamic wireless access in hospital environments.

    Science.gov (United States)

    Phunchongharn, Phond; Hossain, Ekram; Camorlinga, Sergio

    2011-11-01

    We study the multiple access problem for e-Health applications (referred to as secondary users) coexisting with medical devices (referred to as primary or protected users) in a hospital environment. In particular, we focus on transmission scheduling and power control of secondary users in multiple spatial reuse time-division multiple access (STDMA) networks. The objective is to maximize the spectrum utilization of secondary users and minimize their power consumption subject to the electromagnetic interference (EMI) constraints for active and passive medical devices and minimum throughput guarantee for secondary users. The multiple access problem is formulated as a dual objective optimization problem which is shown to be NP-complete. We propose a joint scheduling and power control algorithm based on a greedy approach to solve the problem with much lower computational complexity. To this end, an enhanced greedy algorithm is proposed to improve the performance of the greedy algorithm by finding the optimal sequence of secondary users for scheduling. Using extensive simulations, the tradeoff in performance in terms of spectrum utilization, energy consumption, and computational complexity is evaluated for both the algorithms.

  8. High Level Rule Modeling Language for Airline Crew Pairing

    Science.gov (United States)

    Mutlu, Erdal; Birbil, Ş. Ilker; Bülbül, Kerem; Yenigün, Hüsnü

    2011-09-01

    The crew pairing problem is an airline optimization problem where a set of least costly pairings (consecutive flights to be flown by a single crew) that covers every flight in a given flight network is sought. A pairing is defined by using a very complex set of feasibility rules imposed by international and national regulatory agencies, and also by the airline itself. The cost of a pairing is also defined by using complicated rules. When an optimization engine generates a sequence of flights from a given flight network, it has to check all these feasibility rules to ensure whether the sequence forms a valid pairing. Likewise, the engine needs to calculate the cost of the pairing by using certain rules. However, the rules used for checking the feasibility and calculating the costs are usually not static. Furthermore, the airline companies carry out what-if-type analyses through testing several alternate scenarios in each planning period. Therefore, embedding the implementation of feasibility checking and cost calculation rules into the source code of the optimization engine is not a practical approach. In this work, a high level language called ARUS is introduced for describing the feasibility and cost calculation rules. A compiler for ARUS is also implemented in this work to generate a dynamic link library to be used by crew pairing optimization engines.

  9. Error Prevention as Developed in Airlines

    International Nuclear Information System (INIS)

    Logan, Timothy J.

    2008-01-01

    The airline industry is a high-risk endeavor. Tens of thousands of flights depart each day carrying millions of passengers with the potential for catastrophic consequences. To manage and mitigate this risk, airline operators, labor unions, and the Federal Aviation Administration have developed a partnership approach to improving safety. This partnership includes cooperative programs such as the Aviation Safety Action Partnership and the Flight Operational Quality Assurance. It also involves concentrating on the key aspects of aircraft maintenance reliability and employee training. This report discusses recent enhancements within the airline industry in the areas of proactive safety programs and the move toward safety management systems that will drive improvements in the future

  10. Final Report - Dynamic Path Scheduling through Extensions to Generalized Multiprotocol Label Switching (GMPLS)

    Energy Technology Data Exchange (ETDEWEB)

    Principal Investigator: Dr. Abdella Battou

    2009-05-22

    The major accomplishments of the project are the successful software implementation of the Phase I scheduling algorithms for GMPLS Label Switched Paths (LSPs) and the extension of the IETF Path Computation Element (PCE) Protocol to support scheduling extensions. In performing this work, we have demonstrated the theoretical work of Phase I, analyzed key issues, and made relevant extensions. Regarding the software implementation, we developed a proof of concept prototype as part of our Algorithm Evaluation System (AES). This implementation uses the Linux operating system to provide software portability and will be the foundation for our commercial software. To demonstrate proof of concept, we have implemented LSP scheduling algorithms to support two of the key GMPLS switching technologies (Lambda and Packet) and support both Fixed Path (FP) and Switched Path (SP) routing. We chose Lambda and Packet because we felt it was essential to include both circuit and packet switching technologies as well as to address all-optical switching in the study. As conceptualized in Phase I, the FP algorithms use a traditional approach where the LSP uses the same physical path for the entire service duration while the innovative SP algorithms allow the physical path to vary during the service duration. As part of this study, we have used the AES to conduct a performance analysis using metro size networks (up to 32 nodes) that showed that these algorithms are suitable for commercial implementation. Our results showed that the CPU time required to compute an LSP schedule was small compared to expected inter-arrival time between LSP requests. Also, when the network size increased from 7 to 15 to 32 nodes with 10, 26, and 56 TE links, the CPU processing time showed excellent scaling properties. When Fixed Path and Switched Path routing were compared, SP provided only modestly better performance with respect to LSP completion rate, service duration, path length, and start time deviation

  11. A conceptual framework for measuring airline business model convergence

    OpenAIRE

    Daft, Jost; Albers, Sascha

    2012-01-01

    This paper develops a measurement framework that synthesizes the airline and strategy literature to identify relevant dimensions and elements of airline business models. The applicability of this framework for describing airline strategies and structures and, based on this conceptualization, for assessing the potential convergence of airline business models over time is then illustrated using a small sample of five German passenger airlines. For this sample, the perception of a rapprochement ...

  12. Airline company management: 'Defining of necessary number of employees in airline by using artificial intelligence tools'

    OpenAIRE

    Petrović, Dragan M.; Puharic, Mirjana A.; Jovanović, Tomislav Ž.

    2015-01-01

    In this paper the model for preliminary estimation of number of employees in airline by using of artificial intelligence tools. It is assumed that the tools of artificial intelligence can be applied even for complex tasks such as defining the number of employees in the airline. The results obtained can be used for planning the number of employees, ie. planning the necessary financial investments in human resources, and may also be useful for a preliminary analysis of the airlines that choose ...

  13. Nonlinear dynamic positioning of ships with gain-scheduled wave filtering

    DEFF Research Database (Denmark)

    Torsetnes, Guttorm; Jouffroy, Jerome; Fossen, Thor I.

    This paper presents a globally contracting controller for regulation and dynamic positioning of ships, using only position measurements. For this purpose a globally contracting observer which reconstructs the unmeasured states is constructed. The observer produces accurate estimates of position...

  14. Scheduling with Group Dynamics: a Multi-Robot Task Allocation Algorithm based on Vacancy Chains

    National Research Council Canada - National Science Library

    Dahl, Torbjorn S; Mataric, Maja J; Sukhatme, Gaurav S

    2002-01-01

    .... We present a multi-robot task allocation algorithm that is sensitive to group dynamics. Our algorithm is based on vacancy chains, a resource distribution process common in human and animal societies...

  15. Collective efficacy in a high-fidelity simulation of an airline operations center

    Science.gov (United States)

    Jinkerson, Shanna

    This study investigated the relationships between collective efficacy, teamwork, and team performance. Participants were placed into teams, where they worked together in a high-fidelity simulation of an airline operations center. Each individual was assigned a different role to represent different jobs within an airline (Flight Operations Coordinator, Crew Scheduling, Maintenance, Weather, Flight Scheduling, or Flight Planning.) Participants completed a total of three simulations with an After Action Review between each. Within this setting, both team performance and teamwork behaviors were shown to be positively related to expectations for subsequent performance (collective efficacy). Additionally, teamwork and collective efficacy were not shown to be concomitantly related to subsequent team performance. A chi-square test was used to evaluate existence of performance spirals, and they were not supported. The results of this study were likely impacted by lack of power, as well as a lack of consistency across the three simulations.

  16. • New guidelines for national airline caterers.

    Science.gov (United States)

    1989-06-24

    The Government is to issue new guidelines to prevent food poisoning from airline meals. The proposed action comes in response to recent survey evidence which found contaminated meals served up to passengers.

  17. Airline energy conservation options : summary options

    Science.gov (United States)

    1973-07-27

    In late May, 1973 the task of determining and evaluating measures for conserving fuel consumed by the airline industry was undertaken. This task was a part of the larger effort conducted by the Transportation Systems Center to determine measures that...

  18. EXPLORING THE ROLE OF ALLIANCES, AGREEMENTS AND PARTNERSHIPS IN THE AIRLINE INDUSTRY; THE CASE OF APG NETWORK WITHIN THE ROMANIAN MARKET

    Directory of Open Access Journals (Sweden)

    CAMELIA MONICA GHEORGHE

    2017-08-01

    Full Text Available During the last years, the airline industry had a dynamic evolution, due to significant changes such as: the liberalization of air traffic with two important consequences, the development of the hub and spoke model, as well as the emergence of low-cost companies; the commercialization and privatization of airports; the evolution of technology. In order to be competitive in this new context, taking part of an alliance or network, creating a partnership or an agreement became a key strategy for airlines and as well as other stakeholders involved. This article examines the different partnerships in the airline industry, starting from code-share agreements between airlines or the emergence of airline alliances as a consequence of the hub and spoke system up to the more recent airline-airports partnerships, code-share agreements involving low-cost companies or airline representation agreements for several (new markets. The case study of APG Network will be examined, in order to emphasize the role of GSAs (General Sales Agents in the development strategy of airlines. Moreover, a questionnaire was distributed among travel agencies and airlines operating in Romania, to identify their perception on APG and its impact on the Romanian market.

  19. Financial Analysis Report: Malaysia Airlines 2007 - 2011

    OpenAIRE

    Gilbert O'Neil Mushure

    2014-01-01

    This work is an analysis of the annual reports of Malaysia Airlines Berhad from 2007 to 2011. Profitability analysis was done on the financial statements of the company from 2007 to 2011. Cash and working capital management analysis were done on the financial statements of 2010 and 2011. It was found that Malaysia Airlines Berhad was constantly suffering from high costs of operations which resulted in consecutive negative gross profit over the years.Net profit remained positive only as a resu...

  20. Fuel conservation integrated into airline economics

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, D.R.

    1981-01-01

    Fuel conservation efforts at most major airlines involve close scrutiny and intensive analysis in all areas - flight, maintenance and ground handling. Yet, despite the concern and attention devoted, the fundamental question of fuel saving versus time trade-offs remains unanswered. This paper introduces and defines the concept ''The value of an airplane to an airline is that airplane's earning power.

  1. Cancer treatment scheduling and dynamic heterogeneity in social dilemmas of tumour acidity and vasculature.

    Science.gov (United States)

    Kaznatcheev, Artem; Vander Velde, Robert; Scott, Jacob G; Basanta, David

    2017-03-14

    Tumours are diverse ecosystems with persistent heterogeneity in various cancer hallmarks like self-sufficiency of growth factor production for angiogenesis and reprogramming of energy metabolism for aerobic glycolysis. This heterogeneity has consequences for diagnosis, treatment and disease progression. We introduce the double goods game to study the dynamics of these traits using evolutionary game theory. We model glycolytic acid production as a public good for all tumour cells and oxygen from vascularisation via vascular endothelial growth factor production as a club good benefiting non-glycolytic tumour cells. This results in three viable phenotypic strategies: glycolytic, angiogenic and aerobic non-angiogenic. We classify the dynamics into three qualitatively distinct regimes: (1) fully glycolytic; (2) fully angiogenic; or (3) polyclonal in all three cell types. The third regime allows for dynamic heterogeneity even with linear goods, something that was not possible in prior public good models that considered glycolysis or growth factor production in isolation. The cyclic dynamics of the polyclonal regime stress the importance of timing for anti-glycolysis treatments like lonidamine. The existence of qualitatively different dynamic regimes highlights the order effects of treatments. In particular, we consider the potential of vascular normalisation as a neoadjuvant therapy before follow-up with interventions like buffer therapy.

  2. Optimization Scheduling Model for Wind-thermal Power System Considering the Dynamic penalty factor

    Science.gov (United States)

    PENG, Siyu; LUO, Jianchun; WANG, Yunyu; YANG, Jun; RAN, Hong; PENG, Xiaodong; HUANG, Ming; LIU, Wanyu

    2018-03-01

    In this paper, a new dynamic economic dispatch model for power system is presented.Objective function of the proposed model presents a major novelty in the dynamic economic dispatch including wind farm: introduced the “Dynamic penalty factor”, This factor could be computed by using fuzzy logic considering both the variable nature of active wind power and power demand, and it could change the wind curtailment cost according to the different state of the power system. Case studies were carried out on the IEEE30 system. Results show that the proposed optimization model could mitigate the wind curtailment and the total cost effectively, demonstrate the validity and effectiveness of the proposed model.

  3. Discretionary salt use in airline meal service.

    Science.gov (United States)

    Wallace, S; Wellman, N S; Dierkes, K E; Johnson, P M

    1987-02-01

    Salt use in airline meal service was studied through observation of returned meal trays of 932 passengers. Observation and weighing of salt packets on returned trays revealed that 64% of passengers did not salt their airline dinner, while 6% used the entire salt packet, 0.92 gm NaCl (362 mg Na). Average discretionary salt use among the 234 passengers (25%) who added salt was 0.57 gm NaCl (232 mg Na). Estimates of total sodium in the four airline dinners averaged 2.0 gm NaCl (786 mg Na). Laboratory assays of menu items produced by the airline foodservice differed 3% to 19% from estimated values. Sodium content of the four airline dinner menus was similar and did not affect salt use. Discretionary salt use was related to the total amount of entrée consumed but was not affected by the amount of salad consumed. It is postulated that salt use in the "captive" airline situation is predicated on consistent, habitual practices. Lowering sodium consumption in this setting may require alteration in both food preparation methods and quantity of salt presented in the packets.

  4. Aviation Accidents: CRM to Maintaining the Share of Airlines. Case Study on Accidents Airlines in China

    Science.gov (United States)

    Alnuaimi, Qussay A. B.

    2015-01-01

    We present Aviation Cost Risk management (CRM) methodology designed for Airlines Company, who needs to run projects beyond their normal. These airlines are critical to the survival of these organizations, such as the development and performance. The Aviation crisis can have considerable impact upon the value of the firm. Risk managers must focus…

  5. A Dynamic Resource Scheduling Method Based on Fuzzy Control Theory in Cloud Environment

    OpenAIRE

    Chen, Zhijia; Zhu, Yuanchang; Di, Yanqiang; Feng, Shaochong

    2015-01-01

    The resources in cloud environment have features such as large-scale, diversity, and heterogeneity. Moreover, the user requirements for cloud computing resources are commonly characterized by uncertainty and imprecision. Hereby, to improve the quality of cloud computing service, not merely should the traditional standards such as cost and bandwidth be satisfied, but also particular emphasis should be laid on some extended standards such as system friendliness. This paper proposes a dynamic re...

  6. Impact of environmental constraints and aircraft technology on airline fleet composition

    Science.gov (United States)

    Moolchandani, Kushal A.

    This thesis models an airline's decisions about fleet evolution in order to maintain economic and regulatory viability. The aim is to analyze the fleet evolution under different scenarios of environmental policy and technology availability in order to suggest an optimal fleet under each case. An understanding of the effect of aircraft technologies, fleet size and age distribution, and operational procedures on airline performance may improve the quality of policies to achieve environmental goals. Additionally, the effect of decisions about fleet evolution on air travel is assessed as the change in market demand and profits of an abstracted, benevolent monopolist airline. Attention to the environmental impact of aviation has grown, and this has prompted several organizations such as ICAO (and, in response, NASA) to establish emissions reduction targets to reduce aviation's global climate impact. The introduction of new technology, change in operational procedures, etc. are some of the proposed means to achieve these targets. Of these, this thesis studies the efficacy of implementation of environmental policies in form of emissions constraints as a means to achieve these goals and assesses their impact on an airline's fleet evolution and technology use (along with resulting effects on air travel demand). All studies in this thesis are conducted using the Fleet-level Environmental Evaluation Tool (FLEET), a NASA sponsored simulation tool developed at Purdue University. This tool models airline operational decisions via a resource allocation problem and uses a system dynamics type approach to mimic airline economics, their decisions regarding retirement and acquisition of aircraft and evolution of market demand in response to the economic conditions. The development of an aircraft acquisition model for FLEET is a significant contribution of the author. Further, the author conducted a study of various environmental policies using FLEET. Studies introduce constraints on

  7. A new approach for disruption management in airline operations control

    CERN Document Server

    Castro, António J M; Oliveira, Eugénio

    2014-01-01

    Most of the research efforts dealing with airline scheduling have been done on off-line plan optimization.  However, nowadays, with the increasingly complex and huge traffic at airports, the real challenge is how to react to unexpected events that may cause plan-disruptions, leading to flight delays. Moreover these disruptive events usually affect at least three different dimensions of the situation: the aircraft assigned to the flight, the crew assignment and, often forgotten, the passengers’ journey and satisfaction. This book includes answers to this challenge and proposes the use of the Multi-agent System paradigm to rapidly compose a multi-faceted solution to the disruptive event taking into consideration possible preferences of those three key aspects of the problem. Negotiation protocols taking place between agents that are experts in solving the different problem dimensions, combination of different utility functions and, not less important, the inclusion of the human in the automatic decision-maki...

  8. Impact of Flight Departure Delay on Airline Choice Behavior

    Directory of Open Access Journals (Sweden)

    Taylor Tae-Hwee Lee

    2017-12-01

    Full Text Available The Korean aviation industry (KAI has been expanded significantly, because the Incheon International Airport opened in 2001 and low cost carriers (LCC entered the KAI market. But following the KAI's growth, flight departure delays (FDDs have increased six-fold during the past decade. In terms of these situations, this study firstly adds the FDD variable to an airline choice behavior (ACB model and secondly analyses how FDD impact the ACB. As a result, FDD is relatively less influential on ACB than other attributes. Both the flight service and available schedule are positively related to the choice of full service carriers (FSC. The analysis shows that FSCs’ allotment rate (AR is 85.3%, while LCCs’ one is 14.7%.

  9. Multi-day activity scheduling reactions to planned activities and future events in a dynamic model of activity-travel behavior

    NARCIS (Netherlands)

    Nijland, L.; Arentze, T.A.; Timmermans, H.J.P.

    2014-01-01

    Modeling multi-day planning has received scarce attention in activity-based transport demand modeling so far. However, new dynamic activity-based approaches are being developed at the current moment. The frequency and inflexibility of planned activities and events in activity schedules of

  10. Multi-Day Activity Scheduling Reactions to Planned Activities and Future Events in a Dynamic Model of Activity-Travel Behavior

    NARCIS (Netherlands)

    Nijland, L.; Arentze, T.; Timmermans, H.

    2014-01-01

    Modeling multi-day planning has received scarce attention in activity-based transport demand modeling so far. However, new dynamic activity-based approaches are being developed at the current moment. The frequency and inflexibility of planned activities and events in activity schedules of

  11. Airline Applications of Business Intelligence Systems

    Directory of Open Access Journals (Sweden)

    Mihai ANDRONIE

    2015-09-01

    Full Text Available Airline industry is characterized by large quantities of complex, unstructured and rapid changing data that can be categorized as big data, requiring specialized analysis tools to explore it with the purpose of obtaining useful knowledge as decision support for companies that need to fundament their activities and improve the processes they are carrying on. In this context, business intelligence tools are valuable instruments that can optimally process airline related data so that the activities that are conducted can be optimized to maximize profits, while meeting customer requirements. An airline company that has access to large volumes of data (stored into conventional or big data repositories has two options to extract useful decision support information: processing data by using general-purpose business intelligence systems or processing data by using industry specific business intelligence systems. Each of these two options has both advantages and disadvantages for the airline companies that intend to use them. The present paper presents a comparative study of a number of general-purpose and airline industry specific business intelligence systems, together with their main advantages and disadvantages.

  12. Validation of the Automation Attitude Questionnaire for Airline Pilots ...

    African Journals Online (AJOL)

    AAQ), which assesses airline pilots' perceptions about operating advanced commercial aircraft. A total of 262 airline pilots from a large South African carrier participated in the validation of the instrument. A five-factor measurement model was ...

  13. AIRLINE COMPETITION: Barriers to Entry Continue in Some Domestic Markets

    National Research Council Canada - National Science Library

    1998-01-01

    .... Airline deregulation has led to lower fares and better service for most air travelers largely because of increased competition spurred by the entry of new airlines into the industry and established...

  14. Service Quality in the U.S. Airline Industry: Variations in Performance Within Airlines and Between Airlines and the Industry

    Science.gov (United States)

    Rhoades, Dawna L.; Waguespack, Blaise, Jr.

    2000-01-01

    This study examined the service quality of 25 U.S. airlines (1987-1996) using data from the Department of Transportation's Air Travel Consumer Report. After a total quality and total complaint rate was calculated for these airlines, a 95 percent confidence interval was placed around the yearly and company means calculated to examine those cases that were significantly different from the mean. Results indicate that while the major carriers are converging toward a higher level of quality, there continues to be significant yearly variation. The service quality of regional carriers was much lower than major carriers and showed much greater variation.

  15. An analysis of the proposed Airline Competition Enhancement Act

    OpenAIRE

    Smith, Janice S.

    1990-01-01

    Approved for public release, distribution is unlimited This analysis examines problem issues in the passenger airline industry and determines how the proposed Airline Competition Enhancement Act would impact these issues. A summarization of the history of airline deregulation is followed by an assessment of the factors that are contributing to the call for re-regulation. From this assessment, recommendations for changes to the proposed Airline Competition Enhancement Act are made. Lieut...

  16. The occurrence of Salmonella in airline meals.

    Science.gov (United States)

    Hatakka, M; Asplund, K

    1993-01-01

    The occurrence of Salmonella in airline meals was studied in 1989-1992. Samples were collected from flight kitchens in 29 countries. The material consisted of 400 cold dishes and 1,288 hot dishes as well as salads, cheese plates and deserts. Total number of samples was 2211. Salmonella spp. were isolated from 6 samples; 1 contaminated sample was a cold dish prepared in Bangkok, 1 was a hot dish prepared in Mombasa and the remaining 4 contaminated samples were hot dishes prepared within one week in Beijing. The isolated serotypes were S. ohio, S. manchester and S. braenderup. The contaminated cold dish prepared by a flight kitchen in Bangkok was found to be connected with a Salmonella outbreak which occurred in Finland in 1990. Cold airline dishes containing food of animal origin seems to be more risky as a source of Salmonella infections among airline passengers.

  17. Modeling the impact of improved aircraft operations technologies on the environment and airline behavior

    Science.gov (United States)

    Foley, Ryan Patrick

    The overall goal of this thesis is to determine if improved operations technologies are economically viable for US airlines, and to determine the level of environmental benefits available from such technologies. Though these operational changes are being implemented primarily with the reduction of delay and improvement of throughput in mind, economic factors will drive the rate of airline adoption. In addition, the increased awareness of environmental impacts makes these effects an important aspect of decision-making. Understanding this relationship may help policymakers make decisions regarding implementation of these advanced technologies at airports, and help airlines determine appropriate levels of support to provide for these new technologies. In order to do so, the author models the behavior of a large, profit-seeking airline in response to the introduction of advanced equipage allowing improved operations procedures. The airline response included changes in deployed fleet, assignment of aircraft to routes, and acquisition of new aircraft. From these responses, changes in total fleet-level CO2 emissions and airline profit were tallied. As awareness of the environmental impact of aircraft emissions has grown, several agencies (ICAO, NASA) have moved to place goals for emissions reduction. NASA, in particular, has set goals for emissions reduction through several areas of aircraft technology. Among these are "Operational Improvements," technologies available in the short-term through avionics and airport system upgrades. The studies in this thesis make use of the Fleet-Level Environmental Evaluation Tool (FLEET), a simulation tool developed by Purdue University in support of a NASA-sponsored research effort. This tool models the behavior of a large, profit-seeking airline through an allocation problem. The problem is contained within a systems dynamics type approach that allows feedback between passenger demand, ticket price, and the airline fleet composition

  18. Literature review of the passenger airline business models : Full service carrier, low-cost carrier and charter airlines

    NARCIS (Netherlands)

    Carmona Benitez, R.B.; Lodewijks, G.

    2008-01-01

    The deregulation and liberalization of the air transportation industry have developed three main passenger business models: full service carriers, low-cost carriers, and charter airlines. Deregulation removed regulated fares and routes increasing competition and yields. Airlines business models main

  19. Airline company management: 'Defining of necessary number of employees in airline by using artificial intelligence tools'

    Directory of Open Access Journals (Sweden)

    Petrović Dragan M.

    2015-01-01

    Full Text Available In this paper the model for preliminary estimation of number of employees in airline by using of artificial intelligence tools. It is assumed that the tools of artificial intelligence can be applied even for complex tasks such as defining the number of employees in the airline. The results obtained can be used for planning the number of employees, ie. planning the necessary financial investments in human resources, and may also be useful for a preliminary analysis of the airlines that choose to do restructuring or plan to increase/decrease the number of operations. Results were compared with those obtained by regression analysis.

  20. The Design of a Large Scale Airline Network

    NARCIS (Netherlands)

    Carmona Benitez, R.B.

    2012-01-01

    Airlines invest a lot of money before opening new pax transportation services, for this reason, airlines have to analyze if their profits will overcome the amount of money they have to invest to open new services. The design and analysis of the feasibility of airlines networks can be done by using

  1. Solving the Airline Crew Pairing Problem using Subsequence Generation

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Lusby, Richard Martin; Ryan, David M.

    2010-01-01

    Good and fast solutions to the airline crew pairing problem are highly interesting for the airline industry, as crew costs are the biggest expenditure after fuel for an airline. The crew pairing problem is typically modelled as a set partitioning problem and solved by column generation. However, ...

  2. Solving the Airline Crew Pairing Problem using Subsequence Generation

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Ryan, David; Lusby, Richard Martin

    2009-01-01

    Good and fast solutions to the airline crew pairing problem are highly interesting for the airline industry, as crew costs are the biggest expenditure after fuel for an airline. The crew pairing problem is typically modelled as a set partitioning problem and solved by column generation. However, ...

  3. Jet fuels of higher volatility: An airline view

    Energy Technology Data Exchange (ETDEWEB)

    Trimble, M.H.

    1982-05-01

    Use of jet fuels of higher volatility is reviewed by some airlines periodically on a routine basis. Most often, however, airlines become concerned when aviation kerosine supply problems are encountered or anticipated. The purpose of this paper is to discuss the known principles of fuel selection and how they influence airline consideration.

  4. Dynamic gene expression in fish muscle during recovery growth induced by a fasting-refeeding schedule

    Directory of Open Access Journals (Sweden)

    Esquerré Diane

    2007-11-01

    Full Text Available Abstract Background Recovery growth is a phase of rapid growth that is triggered by adequate refeeding of animals following a period of weight loss caused by starvation. In this study, to obtain more information on the system-wide integration of recovery growth in muscle, we undertook a time-course analysis of transcript expression in trout subjected to a food deprivation-refeeding sequence. For this purpose complex targets produced from muscle of trout fasted for one month and from muscle of trout fasted for one month and then refed for 4, 7, 11 and 36 days were hybridized to cDNA microarrays containing 9023 clones. Results Significance analysis of microarrays (SAM and temporal expression profiling led to the segregation of differentially expressed genes into four major clusters. One cluster comprising 1020 genes with high expression in muscle from fasted animals included a large set of genes involved in protein catabolism. A second cluster that included approximately 550 genes with transient induction 4 to 11 days post-refeeding was dominated by genes involved in transcription, ribosomal biogenesis, translation, chaperone activity, mitochondrial production of ATP and cell division. A third cluster that contained 480 genes that were up-regulated 7 to 36 days post-refeeding was enriched with genes involved in reticulum and Golgi dynamics and with genes indicative of myofiber and muscle remodelling such as genes encoding sarcomeric proteins and matrix compounds. Finally, a fourth cluster of 200 genes overexpressed only in 36-day refed trout muscle contained genes with function in carbohydrate metabolism and lipid biosynthesis. Remarkably, among the genes induced were several transcriptional regulators which might be important for the gene-specific transcriptional adaptations that underlie muscle recovery. Conclusion Our study is the first demonstration of a coordinated expression of functionally related genes during muscle recovery growth

  5. Sampling strategies and stopping criteria for stochastic dual dynamic programming: a case study in long-term hydrothermal scheduling

    Energy Technology Data Exchange (ETDEWEB)

    Homem-de-Mello, Tito [University of Illinois at Chicago, Department of Mechanical and Industrial Engineering, Chicago, IL (United States); Matos, Vitor L. de; Finardi, Erlon C. [Universidade Federal de Santa Catarina, LabPlan - Laboratorio de Planejamento de Sistemas de Energia Eletrica, Florianopolis (Brazil)

    2011-03-15

    The long-term hydrothermal scheduling is one of the most important problems to be solved in the power systems area. This problem aims to obtain an optimal policy, under water (energy) resources uncertainty, for hydro and thermal plants over a multi-annual planning horizon. It is natural to model the problem as a multi-stage stochastic program, a class of models for which algorithms have been developed. The original stochastic process is represented by a finite scenario tree and, because of the large number of stages, a sampling-based method such as the Stochastic Dual Dynamic Programming (SDDP) algorithm is required. The purpose of this paper is two-fold. Firstly, we study the application of two alternative sampling strategies to the standard Monte Carlo - namely, Latin hypercube sampling and randomized quasi-Monte Carlo - for the generation of scenario trees, as well as for the sampling of scenarios that is part of the SDDP algorithm. Secondly, we discuss the formulation of stopping criteria for the optimization algorithm in terms of statistical hypothesis tests, which allows us to propose an alternative criterion that is more robust than that originally proposed for the SDDP. We test these ideas on a problem associated with the whole Brazilian power system, with a three-year planning horizon. (orig.)

  6. Web-based GIS: the vector-borne disease airline importation risk (VBD-AIR) tool.

    Science.gov (United States)

    Huang, Zhuojie; Das, Anirrudha; Qiu, Youliang; Tatem, Andrew J

    2012-08-14

    Over the past century, the size and complexity of the air travel network has increased dramatically. Nowadays, there are 29.6 million scheduled flights per year and around 2.7 billion passengers are transported annually. The rapid expansion of the network increasingly connects regions of endemic vector-borne disease with the rest of the world, resulting in challenges to health systems worldwide in terms of vector-borne pathogen importation and disease vector invasion events. Here we describe the development of a user-friendly Web-based GIS tool: the Vector-Borne Disease Airline Importation Risk Tool (VBD-AIR), to help better define the roles of airports and airlines in the transmission and spread of vector-borne diseases. Spatial datasets on modeled global disease and vector distributions, as well as climatic and air network traffic data were assembled. These were combined to derive relative risk metrics via air travel for imported infections, imported vectors and onward transmission, and incorporated into a three-tier server architecture in a Model-View-Controller framework with distributed GIS components. A user-friendly web-portal was built that enables dynamic querying of the spatial databases to provide relevant information. The VBD-AIR tool constructed enables the user to explore the interrelationships among modeled global distributions of vector-borne infectious diseases (malaria. dengue, yellow fever and chikungunya) and international air service routes to quantify seasonally changing risks of vector and vector-borne disease importation and spread by air travel, forming an evidence base to help plan mitigation strategies. The VBD-AIR tool is available at http://www.vbd-air.com. VBD-AIR supports a data flow that generates analytical results from disparate but complementary datasets into an organized cartographical presentation on a web map for the assessment of vector-borne disease movements on the air travel network. The framework built provides a flexible

  7. optimal scheduling of petroleum products distribution in nigeria

    African Journals Online (AJOL)

    MECHANICAL ENGINEERING

    The study reveals that any variation in supply, demand and ... and storage depots for easy shipment of the products from ... The system should be robust yet simple to support routine ..... (10)Klabjan, D. Topics in airline crew scheduling and ...

  8. Cooperative Game Study of Airlines Based on Flight Frequency Optimization

    Directory of Open Access Journals (Sweden)

    Wanming Liu

    2014-01-01

    Full Text Available By applying the game theory, the relationship between airline ticket price and optimal flight frequency is analyzed. The paper establishes the payoff matrix of the flight frequency in noncooperation scenario and flight frequency optimization model in cooperation scenario. The airline alliance profit distribution is converted into profit distribution game based on the cooperation game theory. The profit distribution game is proved to be convex, and there exists an optimal distribution strategy. The results show that joining the airline alliance can increase airline whole profit, the change of negotiated prices and cost is beneficial to profit distribution of large airlines, and the distribution result is in accordance with aviation development.

  9. Tips for Airline Travelers with Sjogren's Syndrome

    Science.gov (United States)

    ... sjogrens.org for more information on Sjögren’s syndrome. New airline rules can have a profound effect on those with Sjögren’s syndrome. The Sjögren’s Syndrome Foundation continues to work closely with the Transportation Safety Administration (TSA) to ...

  10. European vs. U.S. Airlines

    DEFF Research Database (Denmark)

    Assaf, A. Georg; Josiassen, Alexander

    2012-01-01

    This study measures and compares the efficiency and productivity of European and U.S. airlines, over the period from 2001 to 2008. We measure efficiency by estimating a Bayesian distance frontier model subject to regularity constraints. Productivity estimates are also derived parametrically, based...... growth and related market discussions are also provided....

  11. An Opportunity for Hydrogen Fueled Supersonic Airliners

    Directory of Open Access Journals (Sweden)

    Alex Forbes

    2011-02-01

    Full Text Available This paper takes a new look at the prospects for developing supersonic civil airliners, considering global demographics, climate change issues, fuel prices and technological advances. Dramatic changes have occurred in the demographics, economics, and market intensity of the Eastern Hemisphere since the 1990s. Carbon reduction imperatives provide a major incentive to invest in developing hydrogen-fueled airliners. The “point-to-point” air route architecture has proved viable with long range mid-size airliners. With a cruise Mach number of 1.4, a large number of destinations become viable for overland supersonic flight. A conceptual design process is used to estimate cost per seat mile for a range of hydrocarbon and hydrogen fuel costs. An argument based on the ideal shape for minimal wave drag, estimates the drag penalty from using hydrogen. Viable aircraft geometries are shown to exist, that match the theoretical ideal shape, showing that the drag estimate is achievable. Conservative design arguments and market estimates suggest that hydrogen-fueled airliners can achieve seat-mile costs low enough to open a large worldwide market and justify a viable fleet size.

  12. LEASING AS IMPORTANT TOOL OF AIRLINE FINANCING

    Directory of Open Access Journals (Sweden)

    V. G. Afanasiev

    2014-01-01

    Full Text Available The article corers current state of airline financing using such instrument as aviation leasing indifferent forms, such as finance leasing its different forms, operational leasing and its different types, sale and lease back analyzed all pluses and minuses of each form. The main questions of Capetown Convention on international warranties concerning moving equipment also discussed.

  13. 75 FR 32318 - Enhancing Airline Passenger Protections

    Science.gov (United States)

    2010-06-08

    ... if submitted on behalf of an association, a business, a labor union, etc.). You may review DOT's... businesses, and local government entities, that rulemaking is occurring in areas of interest to them; (2... complaints received through social networking mediums such as Facebook or Twitter. Do airlines currently...

  14. Interfaces Visualize Data for Airline Safety, Efficiency

    Science.gov (United States)

    2014-01-01

    As the A-Train Constellation orbits Earth to gather data, NASA scientists and partners visualize, analyze, and communicate the information. To this end, Langley Research Center awarded SBIR funding to Fairfax, Virginia-based WxAnalyst Ltd. to refine the company's existing user interface for Google Earth to visualize data. Hawaiian Airlines is now using the technology to help manage its flights.

  15. Energy management in the Canadian airline industry

    Energy Technology Data Exchange (ETDEWEB)

    1982-09-01

    The purpose of this report was to outline the current status of the Canadian airline industry's energy performance and to outline energy management programs undertaken within the industry. The study also provides an aviation energy management information base developed through a comprehensive computer bibliographical review. A survey of the industry was undertaken, the results of which are incorporated in this report. The Canadian airline industry has recognized the importance of energy management and considerable measures have been introduced to become more energy efficient. The largest single contributor to improved productivity is the acquisition of energy efficient aircraft. Larger airlines in particular have implemented a number of conservation techniques to reduce fuel consumption. However, both large and small airlines would further benefit through incorporating techniques and programs described in the annotated bibliography in this study. Rising fuel prices and economic uncertainties will be contributing factors to a smaller average annual growth in fuel consumption during the 1980s. The lower consumption levels will also be a result of continuing energy conservation awareness, new technology improvements, and improvements in air traffic control. 98 refs., 4 figs., 6 tabs.

  16. Economic and Environmental Effects of Airline Deregulation

    NARCIS (Netherlands)

    Schipper, Youdi; Rietveld, Piet

    1997-01-01

    This paper deals with the issue of regulatory reform in the airline industry, in connection with environmental externalities. Deregulation has led to shorter routes, higher frequencies, probably larger aircraft sizes and more intense peak traffic at airports. In addition, deregulation has led to

  17. The UNO Aviation Monograph Series: The Airline Quality Rating 1998

    Science.gov (United States)

    Bowen, Brent D.; Headley, Dean E.

    1998-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline performance on combined multiple factors important to consumers. Development history and calculation details for the AQR rating system are detailed in The Airline Quality Rating 1991 issued in April, 1991, by the National Institute for Aviation Research at Wichita State University. This current report, Airline Quality Rating 1998, contains monthly Airline Quality Rating scores for 1997. Additional copies are available by contacting Wichita State University or University of Nebraska at Omaha. The Airline Quality Rating 1998 is a summary of month-by-month quality ratings for the ten major U.S. airlines operating during 1997. Using the Airline Quality Rating system and monthly performance data for each airline for the calendar year of 1997, individual and comparative ratings are reported. This research monograph contains a brief summary of the AQR methodology, detailed data and charts that track comparative quality for major airlines domestic operations for the 12 month period of 1997, and industry average results. Also, comparative Airline Quality Rating data for 1991 through 1996 are included to provide a longer term view of quality in the industry.

  18. The UNO Aviation Monograph Series: The Airline Quality Rating 1997

    Science.gov (United States)

    Bowen, Brent D.; Headley, Dean E.

    1997-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline performance on combined multiple factors important to consumers. Development history and calculation details for the AQR rating system are detailed in The Airline Quality Rating 1991 issued in April, 1991, by the National Institute for Aviation Research at Wichita State University. This current report, Airline Rating 1997, contains monthly Airline Quality Rating scores for 1996. Additional copies are available by contacting Wichita State University or the University of Nebraska at Omaha. The Airline Quality Rating (AQR) 1997 is a summary of a month-by-month quality ratings for the nine major domestic U.S. airlines operating during 1996. Using the Airline Quality Rating system and monthly performance data for each airline for the calendar year of 1996, individual and comparative ratings are reported. This research monograph contains a brief summary of the AQR methodology, detailed data and charts that track comparative quality for major domestic airlines across the 12 month period of 1996, and industry average results. Also comparative Airline Quality Rating data for 1991 through 1995 are included to provide a longer term view of quality in the industry.

  19. The Effects of Commercial Airline Traffic on LSST Observing Efficiency

    Science.gov (United States)

    Gibson, Rose; Claver, Charles; Stubbs, Christopher

    2016-01-01

    The Large Synoptic Survey Telescope (LSST) is a ten-year survey that will map the southern sky in six different filters 800 times before the end of its run. In this paper, we explore the primary effect of airline traffic on scheduling the LSST observations in addition to the secondary effect of condensation trails, or contrails, created by the presence of the aircraft. The large national investment being made in LSST implies that small improvments observing efficiency through aircraft and contrail avoidance can result in a significant improvement in the quality of the survey and its science. We have used the Automatic Dependent Surveillance-Broadcast (ADS-B) signals received from commercial aircraft to monitor and record activity over the LSST site. We installed a ADS-B ground station on Cerro Pachón, Chile consiting of a1090Mhz antenna on the Andes Lidar Observatory feeding a RTL2832U software defined radio. We used dump1090 to convert the received ADS-B telementry into Basestation format, where we found that during the busiest time of the night there were only 4 signals being received each minute on average, which will have very small direct effect, if any, on the LSST observing scheduler. As part of future studies we will examin the effects of contrals on LSST observations. Gibson was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experience for Undergraduates Program (AST-1262829).

  20. An Examination of How Ratings of Airlines are Effected by Different Types of Information: A Mediation Analysis

    Science.gov (United States)

    Ozyurek, Abdullah Selim

    Many dynamics directly or indirectly influence the decision-making process. An individual's demographic features, such as gender, country of origin, and emotions are some of the dynamics. In the aviation domain, air passengers purchase their air travel tickets under those dynamics. The purpose of this study was to determine if the airline type, gender of participants, and participants' country of origin had an effect on ratings of an individual's perception of safety and willingness to fly, and which emotions had a mediating effect on this relationship. The study included Lufthansa Airlines and Turkish Airlines from Europe. The affect was the participants' feeling outcomes of presented airline information. The feelings were Ekman and Friesen's (1971) universal emotions that include happiness, surprise, fear, disgust, anger, and sadness. The results of the study indicated that airline type, gender, and country of origin had a statistically significant effect and significant interaction on safety perception and willingness to fly. Also, emotions were found significant mediators on the mediation paths. Particularly happiness, fear, anger, and disgust emotions had a significant influence on participants' decision outcomes.

  1. Relationship between Brazilian airline pilot errors and time of day

    Directory of Open Access Journals (Sweden)

    M.T. de Mello

    2008-12-01

    Full Text Available Flight safety is one of the most important and frequently discussed issues in aviation. Recent accident inquiries have raised questions as to how the work of flight crews is organized and the extent to which these conditions may have been contributing factors to accidents. Fatigue is based on physiologic limitations, which are reflected in performance deficits. The purpose of the present study was to provide an analysis of the periods of the day in which pilots working for a commercial airline presented major errors. Errors made by 515 captains and 472 copilots were analyzed using data from flight operation quality assurance systems. To analyze the times of day (shifts during which incidents occurred, we divided the light-dark cycle (24:00 in four periods: morning, afternoon, night, and early morning. The differences of risk during the day were reported as the ratio of morning to afternoon, morning to night and morning to early morning error rates. For the purposes of this research, level 3 events alone were taken into account, since these were the most serious in which company operational limits were exceeded or when established procedures were not followed. According to airline flight schedules, 35% of flights take place in the morning period, 32% in the afternoon, 26% at night, and 7% in the early morning. Data showed that the risk of errors increased by almost 50% in the early morning relative to the morning period (ratio of 1:1.46. For the period of the afternoon, the ratio was 1:1.04 and for the night a ratio of 1:1.05 was found. These results showed that the period of the early morning represented a greater risk of attention problems and fatigue.

  2. Relationship between Brazilian airline pilot errors and time of day.

    Science.gov (United States)

    de Mello, M T; Esteves, A M; Pires, M L N; Santos, D C; Bittencourt, L R A; Silva, R S; Tufik, S

    2008-12-01

    Flight safety is one of the most important and frequently discussed issues in aviation. Recent accident inquiries have raised questions as to how the work of flight crews is organized and the extent to which these conditions may have been contributing factors to accidents. Fatigue is based on physiologic limitations, which are reflected in performance deficits. The purpose of the present study was to provide an analysis of the periods of the day in which pilots working for a commercial airline presented major errors. Errors made by 515 captains and 472 co-pilots were analyzed using data from flight operation quality assurance systems. To analyze the times of day (shifts) during which incidents occurred, we divided the light-dark cycle (24:00) in four periods: morning, afternoon, night, and early morning. The differences of risk during the day were reported as the ratio of morning to afternoon, morning to night and morning to early morning error rates. For the purposes of this research, level 3 events alone were taken into account, since these were the most serious in which company operational limits were exceeded or when established procedures were not followed. According to airline flight schedules, 35% of flights take place in the morning period, 32% in the afternoon, 26% at night, and 7% in the early morning. Data showed that the risk of errors increased by almost 50% in the early morning relative to the morning period (ratio of 1:1.46). For the period of the afternoon, the ratio was 1:1.04 and for the night a ratio of 1:1.05 was found. These results showed that the period of the early morning represented a greater risk of attention problems and fatigue.

  3. A Correlational Study of How Airline Customer Service and Consumer Perception of Airline Customer Service Affect the Air Rage Phenomenon

    Science.gov (United States)

    Hunter, Joyce A.

    2007-01-01

    Between 1995 and 2000, customer service declined throughout the airline industry, as reported in February 2001 by the U.S. Department of Transportation (2001). One of the biggest problems today within the airline industry is the constant complaining from customers regarding the deterioraton of service (McCollough, Berry, & Yadav, 2000). Since 1995, unfortunately no airline has been immune from service deterioration, as reported by the Airline Quality Rating, an annual report by two airline industry experts who analyzed Department of Transportation statistics (Harrison & Kleinsasser, 1999). The airline' refusal to recognize the issue of customer service has perpetuated an environment that has become dangerous and detrimental to the traveling public as well as to airline employees, which in turn has fueled a new phenomenon, now referred to as "air rage".

  4. Refinery scheduling

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Marcus V.; Fraga, Eder T. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Shah, Nilay [Imperial College, London (United Kingdom)

    2004-07-01

    This work addresses the refinery scheduling problem using mathematical programming techniques. The solution adopted was to decompose the entire refinery model into a crude oil scheduling and a product scheduling problem. The envelope for the crude oil scheduling problem is composed of a terminal, a pipeline and the crude area of a refinery, including the crude distillation units. The solution method adopted includes a decomposition technique based on the topology of the system. The envelope for the product scheduling comprises all tanks, process units and products found in a refinery. Once crude scheduling decisions are Also available the product scheduling is solved using a rolling horizon algorithm. All models were tested with real data from PETROBRAS' REFAP refinery, located in Canoas, Southern Brazil. (author)

  5. Measuring the potential of individual airports for pandemic spread over the world airline network.

    Science.gov (United States)

    Lawyer, Glenn

    2016-02-09

    Massive growth in human mobility has dramatically increased the risk and rate of pandemic spread. Macro-level descriptors of the topology of the World Airline Network (WAN) explains middle and late stage dynamics of pandemic spread mediated by this network, but necessarily regard early stage variation as stochastic. We propose that much of this early stage variation can be explained by appropriately characterizing the local network topology surrounding an outbreak's debut location. Based on a model of the WAN derived from public data, we measure for each airport the expected force of infection (AEF) which a pandemic originating at that airport would generate, assuming an epidemic process which transmits from airport to airport via scheduled commercial flights. We observe, for a subset of world airports, the minimum transmission rate at which a disease becomes pandemically competent at each airport. We also observe, for a larger subset, the time until a pandemically competent outbreak achieves pandemic status given its debut location. Observations are generated using a highly sophisticated metapopulation reaction-diffusion simulator under a disease model known to well replicate the 2009 influenza pandemic. The robustness of the AEF measure to model misspecification is examined by degrading the underlying model WAN. AEF powerfully explains pandemic risk, showing correlation of 0.90 to the transmission level needed to give a disease pandemic competence, and correlation of 0.85 to the delay until an outbreak becomes a pandemic. The AEF is robust to model misspecification. For 97 % of airports, removing 15 % of airports from the model changes their AEF metric by less than 1 %. Appropriately summarizing the size, shape, and diversity of an airport's local neighborhood in the WAN accurately explains much of the macro-level stochasticity in pandemic outcomes.

  6. Salmonella outbreak among railway and airline passengers.

    Science.gov (United States)

    Hatakka, M

    1992-01-01

    A widespread outbreak by Salmonella infantis, infecting a total of 226 people, occurred in Finland at the beginning of August 1986. Of those infected, 107 were railway passengers, 91 were airline passengers and 28 were employed in a food processing establishment. The outbreak among the railway passengers was caused by egg sandwiches, the airline passengers were infected by a meal served on board and the catering employees by the breakfast served in the establishment. The outbreak was caused by food prepared in the establishment's kitchen. The employees' breakfasts had probably been contaminated by an employee who was a symptom-free Salmonella infantis carrier, and a number of the employees subsequently became infected, leading to widespread contamination of the food prepared in the establishment. The spread of the outbreak was further influenced by a heatwave at the time and by shortcomings in the cold storage facilities. The kitchen's hygiene supervision and the quality control of its output were reorganized after the outbreak.

  7. Airline experience with reliability-centered maintenance

    International Nuclear Information System (INIS)

    Matteson, T.D.

    1985-01-01

    Reliability-Centered Maintenance is a process for developing preventive maintenance programs. Its concepts evolved from the post WWII experience of the airline community. Its genesis was in a paper by F. Stanley Nowlan and Thomas D. Matteson of United Airlines for the American Institute of Aeronautics and Astronautics in 1967. Its first application was to the Boeing 747. It has subsequently been adopted by the FAA and the Department of Defense and applied to many new transport and military aircraft. Its objective is applicable and effective preventive maintenance and it has proven to be a highly effective replacement for the prior intuitive processes for selective preventive maintenance tasks. It focuses on system functions, functional failures, then dominant failure modes and effects. It then uses a decision tree to classify failure criticality and identify applicable and effective tasks. The result is a program focused on maintaining inherent safety and reliability at minimum cost. (orig.)

  8. Airline experience with reliability-centered maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Matteson, T.D.

    1985-11-01

    Reliability-Centered Maintenance is a process for developing preventive maintenance programs. Its concepts evolved from the post WWII experience of the airline community. Its genesis was in a paper by F. Stanley Nowlan and Thomas D. Matteson of United Airlines for the American Institute of Aeronautics and Astronautics in 1967. Its first application was to the Boeing 747. It has subsequently been adopted by the FAA and the Department of Defense and applied to many new transport and military aircraft. Its objective is applicable and effective preventive maintenance and it has proven to be a highly effective replacement for the prior intuitive processes for selective preventive maintenance tasks. It focuses on system functions, functional failures, then dominant failure modes and effects. It then uses a decision tree to classify failure criticality and identify applicable and effective tasks. The result is a program focused on maintaining inherent safety and reliability at minimum cost. (orig.).

  9. Enhancing Safety at Airline Operations Control Centre

    Directory of Open Access Journals (Sweden)

    Lukáš Řasa

    2015-04-01

    Full Text Available In recent years a new term of Safety Management System (SMS has been introduced into aviation legislation. This system is being adopted by airline operators. One of the groundbased actors of everyday operations is Operations Control Centre (OCC. The goal of this article has been to identify and assess risks and dangers which occur at OCC and create a template for OCC implementation into SMS.

  10. RELEVANCE OF PROCESS RISK ASSESSMENT IN AIRLINES

    OpenAIRE

    Oksana G. Feoktistova; Igor K. Turkin; Sergey V. Barinov

    2017-01-01

    The notion of “the concept on assumed risk” that took over from the outdated concept of absolute security is analyzed, the increasing significance of operating risk assessment at the present stage is noted. Some basic risk assessment techniques are considered. Matrix technique of risk assessment is considered more thoroughly, and it may be used in risk assessment of airlines in the context of labour protection management system.The ability to correctly assess risks and develop appropriate pre...

  11. Fatigue Monitoring Tool for Airline Operators (FMT

    Directory of Open Access Journals (Sweden)

    Gislason Sigurdur Hrafn

    2017-12-01

    Full Text Available A Fatigue Monitoring Tool (FMT model was constructed for an operational airline in order to manage the fatigue levels of their crews in accordance with Fatigue Risk Management System (FRMS practices. This article describes the implementation of the Fatigue Monitoring Tool model and the airline’s aims to put the recent scientific findings on aviation fatigue into practical use. The model consists of proxy points allotted to various duties and rest periods.

  12. RELEVANCE OF PROCESS RISK ASSESSMENT IN AIRLINES

    Directory of Open Access Journals (Sweden)

    Oksana G. Feoktistova

    2017-01-01

    Full Text Available The notion of “the concept on assumed risk” that took over from the outdated concept of absolute security is analyzed, the increasing significance of operating risk assessment at the present stage is noted. Some basic risk assessment techniques are considered. Matrix technique of risk assessment is considered more thoroughly, and it may be used in risk assessment of airlines in the context of labour protection management system.The ability to correctly assess risks and develop appropriate precautionary measures will allow airlines to avoid incidents leading to drastic consequences for staff, as well as to direct and indirect costs for the enterprise among which there could be singled out both direct property damage and loss of profit and expenses connected to incident investigation, penalty and compensation payment, loss of business reputation and so on. To reduce the rate of accidents and to develop safe activities skills for airlines staff a risk assessment chart is supposed to be implemented, which will be an efficient accidents prevention involving the staff in the process and making them follow safe working conditions.Process risk assessment is an integral part of assessment of the whole enterprise activity and work efficiency of a department and particular workers evaluation system. Labour protection activity should be based on risk identification and its control. Risk assessment is a keystone of labour protection activity planning.

  13. Outsourcing in air transportation industry: the case of Turkish Airlines

    OpenAIRE

    Durmaz, Vildan; Adiller, Leyla

    2010-01-01

    Air transportation industry, in all over the world, is developing and changing day by day in a very competitive environment. Airline companies have to adopt themselves using different strategies to give more efficient and effective services to survive in that market. Outsourcing is one of these strategies to be able to reach the sustainability of airline companies. The main aim of this paper is to discuss the importance of outsourcing for the airline companies. For this reason, first outso...

  14. The Evolution of U.S. Airline Competition

    OpenAIRE

    Severin Borenstein

    1992-01-01

    The next section reviews the evolution of the domestic airline industry since the late 1970s, when it was abruptly freed from most regulatory constraints on pricing, entry, and exit. (International air travel is considered here only as it relates to competition in the domestic industry.) The following sections will examine structure issues and strategic developments in airline competition and discuss public policy options in dealing with the airline industry.

  15. Schedule Analytics

    Science.gov (United States)

    2016-04-30

    Warfare, Naval Sea Systems Command Acquisition Cycle Time : Defining the Problem David Tate, Institute for Defense Analyses Schedule Analytics Jennifer...research was comprised of the following high- level steps :  Identify and review primary data sources 1...research. However, detailed reviews of the OMB IT Dashboard data revealed that schedule data is highly aggregated. Program start date and program end date

  16. An Economic Model of U.S. Airline Operating Expenses

    Science.gov (United States)

    Harris, Franklin D.

    2005-01-01

    This report presents a new economic model of operating expenses for 67 airlines. The model is based on data that the airlines reported to the United States Department of Transportation in 1999. The model incorporates expense-estimating equations that capture direct and indirect expenses of both passenger and cargo airlines. The variables and business factors included in the equations are detailed enough to calculate expenses at the flight equipment reporting level. Total operating expenses for a given airline are then obtained by summation over all aircraft operated by the airline. The model's accuracy is demonstrated by correlation with the DOT Form 41 data from which it was derived. Passenger airlines are more accurately modeled than cargo airlines. An appendix presents a concise summary of the expense estimating equations with explanatory notes. The equations include many operational and aircraft variables, which accommodate any changes that airline and aircraft manufacturers might make to lower expenses in the future. In 1999, total operating expenses of the 67 airlines included in this study amounted to slightly over $100.5 billion. The economic model reported herein estimates $109.3 billion.

  17. Airline business continuity and IT disaster recovery sites.

    Science.gov (United States)

    Haji, Jassim

    2016-01-01

    Business continuity is defined as the capability of the organisation to continue delivery of products or services at acceptable predefined levels following a disruptive incident. Business continuity is fast evolving to become a critical and strategic decision for any organisation. Transportation in general, and airlines in particular, is a unique sector with a specialised set of requirements, challenges and opportunities. Business continuity in the airline sector is a concept that is generally overlooked by the airline managements. This paper reviews different risks related to airline processes and will also propose solutions to these risks based on experiences and good industry practices.

  18. The Hybrid Airline Model. Generating Quality for Passengers

    Directory of Open Access Journals (Sweden)

    Bogdan AVRAM

    2017-12-01

    Full Text Available This research aims to investigate the different strategies adopted by the airline companies in adapting to the ongoing changes while developing products and services for passengers in order to increase their yield, load factor and passenger satisfaction. Finding a balance between costs and services quality in the airline industry is a crucial task for every airline wanting to gain a competitive advantage on the market. Also, the rise of the hybrid business operating model has brought up many challenges for airlines as the line between legacy carriers and low-cost carriers is getting thinner in terms of costs and innovative ideas to create a superior product for the passengers.

  19. Identifying Strategic Factors of the Implantation CSR in the Airline Industry: The Case of Asia-Pacific Airlines

    Directory of Open Access Journals (Sweden)

    Dong-Shang Chang

    2015-06-01

    Full Text Available Sustainable development has always been the objective of many fields, including the tourism and transportation sector. However, a major part of this sector, the airline industry, deals with many negative impacts, such as air pollution, noise, CO2 emission, and labor practice. Corporate social responsibility (CSR is a strategic business activity that can enhance the sustainability of the airline industry. The results of the Dow Jones Sustainability Indices (DJSI reveal that airlines of Western countries exhibit a more remarkable CSR performance than Asia-Pacific airlines, suggesting that the CSR programs of Asia-Pacific airlines need improvement. By constructing an evaluation hierarchy and applying the decision-making trial and evaluation laboratory (DEMATEL method, this study found that the key strategic factors in the airline industry’s implementation of CSR include corporate governance, risk and crisis management, brand management, and product responsibility (safety.

  20. Future aircraft networks and schedules

    Science.gov (United States)

    Shu, Yan

    2011-07-01

    computational results of these large-scale instances. To validate the models and solution algorithms developed, this thesis also compares the daily flight schedules that it designs with the schedules of the existing airlines. Furthermore, it creates instances that represent different economic and fuel-prices conditions and derives schedules under these different conditions. In addition, it discusses the implication of using new aircraft in the future flight schedules. Finally, future research in three areas---model, computational method, and simulation for validation---is proposed.

  1. Fatigue mitigation effects of en-route napping on commercial airline pilots flying international routes

    Science.gov (United States)

    Baldwin, Jarret Taylor

    The introduction of ultra-long range commercial aircraft and the evolution of the commercial airline industry has provided new opportunities for air carriers to fly longer range international route segments while deregulation, industry consolidation, and the constant drive to reduce costs wherever possible has pressured airline managements to seek more productivity from their pilots. At the same time, advancements in the understanding of human physiology have begun to make their way into flight and duty time regulations and airline scheduling practices. In this complex and ever changing operating environment, there remains an essential need to better understand how these developments, and other daily realities facing commercial airline pilots, are affecting their fatigue management strategies as they go about their rituals of getting to and from their homes to work and performing their flight assignments. Indeed, the need for commercial airline pilots to have access to better and more effective fatigue mitigation tools to combat fatigue and insure that they are well rested and at the top of their game when flying long-range international route segments has never been greater. This study examined to what extent the maximum fatigue states prior to napping, as self-accessed by commercial airline pilots flying international route segments, were affected by a number of other common flight assignment related factors. The study also examined to what extent the availability of scheduled en-route rest opportunities, in an onboard crew rest facility, affected the usage of en-route napping as a fatigue mitigation strategy, and to what extent the duration of such naps affected the perceived benefits of such naps as self-accessed by commercial airline pilots flying international route segments. The study utilized an online survey tool to collect data on crew position, prior flight segments flown in the same duty period, augmentation, commuting, pre-flight rest obtained in the

  2. An Analysis of Airline Costs. Lecture Notes for MIT Courses. 16.73 Airline Management and Marketing

    Science.gov (United States)

    Simpson, R. W.

    1972-01-01

    The cost analyst must understand the operations of the airline and how the activities of the airline are measured, as well as how the costs are incurred and recorded. The data source is usually a cost accounting process. This provides data on the cumulated expenses in various categories over a time period like a quarter, or year, and must be correlated by the analyst with cumulated measures of airline activity which seem to be causing this expense.

  3. Circadian phase, dynamics of subjective sleepiness and sensitivity to blue light in young adults complaining of a delayed sleep schedule.

    Science.gov (United States)

    Moderie, Christophe; Van der Maren, Solenne; Dumont, Marie

    2017-06-01

    To assess factors that might contribute to a delayed sleep schedule in young adults with sub-clinical features of delayed sleep phase disorder. Two groups of 14 young adults (eight women) were compared: one group complaining of a delayed sleep schedule and a control group with an earlier bedtime and no complaint. For one week, each subject maintained a target bedtime reflecting their habitual sleep schedule. Subjects were then admitted to the laboratory for the assessment of circadian phase (dim light melatonin onset), subjective sleepiness, and non-visual light sensitivity. All measures were timed relative to each participant's target bedtime. Non-visual light sensitivity was evaluated using subjective sleepiness and salivary melatonin during 1.5-h exposure to blue light, starting one hour after target bedtime. Compared to control subjects, delayed subjects had a later circadian phase and a slower increase of subjective sleepiness in the late evening. There was no group difference in non-visual sensitivity to blue light, but we found a positive correlation between melatonin suppression and circadian phase within the delayed group. Our results suggest that a late circadian phase, a slow build-up of sleep need, and an increased circadian sensitivity to blue light contribute to the complaint of a delayed sleep schedule. These findings provide targets for strategies aiming to decreasing the severity of a sleep delay and the negative consequences on daytime functioning and health. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Project Schedule Simulation

    DEFF Research Database (Denmark)

    Mizouni, Rabeb; Lazarova-Molnar, Sanja

    2015-01-01

    overrun both their budget and time. To improve the quality of initial project plans, we show in this paper the importance of (1) reflecting features’ priorities/risk in task schedules and (2) considering uncertainties related to human factors in plan schedules. To make simulation tasks reflect features......’ priority as well as multimodal team allocation, enhanced project schedules (EPS), where remedial actions scenarios (RAS) are added, were introduced. They reflect potential schedule modifications in case of uncertainties and promote a dynamic sequencing of involved tasks rather than the static conventional...... this document as an instruction set. The electronic file of your paper will be formatted further at Journal of Software. Define all symbols used in the abstract. Do not cite references in the abstract. Do not delete the blank line immediately above the abstract; it sets the footnote at the bottom of this column....

  5. Efficient Scheduling of Scientific Workflows with Energy Reduction Using Novel Discrete Particle Swarm Optimization and Dynamic Voltage Scaling for Computational Grids

    Directory of Open Access Journals (Sweden)

    M. Christobel

    2015-01-01

    Full Text Available One of the most significant and the topmost parameters in the real world computing environment is energy. Minimizing energy imposes benefits like reduction in power consumption, decrease in cooling rates of the computing processors, provision of a green environment, and so forth. In fact, computation time and energy are directly proportional to each other and the minimization of computation time may yield a cost effective energy consumption. Proficient scheduling of Bag-of-Tasks in the grid environment ravages in minimum computation time. In this paper, a novel discrete particle swarm optimization (DPSO algorithm based on the particle’s best position (pbDPSO and global best position (gbDPSO is adopted to find the global optimal solution for higher dimensions. This novel DPSO yields better schedule with minimum computation time compared to Earliest Deadline First (EDF and First Come First Serve (FCFS algorithms which comparably reduces energy. Other scheduling parameters, such as job completion ratio and lateness, are also calculated and compared with EDF and FCFS. An energy improvement of up to 28% was obtained when Makespan Conservative Energy Reduction (MCER and Dynamic Voltage Scaling (DVS were used in the proposed DPSO algorithm.

  6. Efficient Scheduling of Scientific Workflows with Energy Reduction Using Novel Discrete Particle Swarm Optimization and Dynamic Voltage Scaling for Computational Grids

    Science.gov (United States)

    Christobel, M.; Tamil Selvi, S.; Benedict, Shajulin

    2015-01-01

    One of the most significant and the topmost parameters in the real world computing environment is energy. Minimizing energy imposes benefits like reduction in power consumption, decrease in cooling rates of the computing processors, provision of a green environment, and so forth. In fact, computation time and energy are directly proportional to each other and the minimization of computation time may yield a cost effective energy consumption. Proficient scheduling of Bag-of-Tasks in the grid environment ravages in minimum computation time. In this paper, a novel discrete particle swarm optimization (DPSO) algorithm based on the particle's best position (pbDPSO) and global best position (gbDPSO) is adopted to find the global optimal solution for higher dimensions. This novel DPSO yields better schedule with minimum computation time compared to Earliest Deadline First (EDF) and First Come First Serve (FCFS) algorithms which comparably reduces energy. Other scheduling parameters, such as job completion ratio and lateness, are also calculated and compared with EDF and FCFS. An energy improvement of up to 28% was obtained when Makespan Conservative Energy Reduction (MCER) and Dynamic Voltage Scaling (DVS) were used in the proposed DPSO algorithm. PMID:26075296

  7. Concurrent airline fleet allocation and aircraft design with profit modeling for multiple airlines

    Science.gov (United States)

    Govindaraju, Parithi

    A "System of Systems" (SoS) approach is particularly beneficial in analyzing complex large scale systems comprised of numerous independent systems -- each capable of independent operations in their own right -- that when brought in conjunction offer capabilities and performance beyond the constituents of the individual systems. The variable resource allocation problem is a type of SoS problem, which includes the allocation of "yet-to-be-designed" systems in addition to existing resources and systems. The methodology presented here expands upon earlier work that demonstrated a decomposition approach that sought to simultaneously design a new aircraft and allocate this new aircraft along with existing aircraft in an effort to meet passenger demand at minimum fleet level operating cost for a single airline. The result of this describes important characteristics of the new aircraft. The ticket price model developed and implemented here enables analysis of the system using profit maximization studies instead of cost minimization. A multiobjective problem formulation has been implemented to determine characteristics of a new aircraft that maximizes the profit of multiple airlines to recognize the fact that aircraft manufacturers sell their aircraft to multiple customers and seldom design aircraft customized to a single airline's operations. The route network characteristics of two simple airlines serve as the example problem for the initial studies. The resulting problem formulation is a mixed-integer nonlinear programming problem, which is typically difficult to solve. A sequential decomposition strategy is applied as a solution methodology by segregating the allocation (integer programming) and aircraft design (non-linear programming) subspaces. After solving a simple problem considering two airlines, the decomposition approach is then applied to two larger airline route networks representing actual airline operations in the year 2005. The decomposition strategy serves

  8. Space weather effects and commerical airlines

    Science.gov (United States)

    Jones, J.; Bentley, R.; Hunter, R.; Taylor, G.; Thomas, D.

    Space Weather (SW) phenomena can effect many areas of commercial airline operations including avionics, communications and GPS navigation systems. Of particular importance at present is the recently introduced EU legislation requiring the monitoring of aircrew radiation exposure, including any variations at aircraft altitudes due to solar activity. The Mullard Space Science Laboratory is collaborating with Virgin Atlantic Airways, the Civil Aviation Authority and the National Physical Laboratory on a 3- year project to monitor the levels of cosmic radiation on long-haul flights. The study will determine whether computer models currently used to predict radiation exposure of aircrew are adequate. It also aims to determine whether solar or geomagnetic activity can cause significant modifications to the doses. This presentation will begin by showing some of the preliminary results obtained so far. As an example, we present a comparison of flight doses measured following the 14t h July 2000 X - class flare that was accompanied by a major Solar Particle Event (SPE). The results highlight the importance of a range of external factors that can strongly influence how SPEs may effect the measured dose at aircraft altitudes. At present, any SPE contributions in the airlines' dose records can only be poorly estimated retrospectively. Ideally, it would be better to try to avoid operating during these possibly significant radiation - enhancing events by utilising SW information (alerts, warnings, etc.). However, doing so poses many difficult operational problems for such a heavily regulated international industry, in terms of safety, security and procedures. Therefore, the use of timely SW information, which is still very unreliable, in a similar manner to terrestrial weather will require agreement from the International Civil Aviation Organisation (ICAO) and International Air Transport Association (IATA) to Air Traffic Control and Aviation Regulatory Authority's. This

  9. Approaches to construction of systems of safety management in airlines

    Directory of Open Access Journals (Sweden)

    2015-01-01

    Full Text Available The article presents three approaches of building a safety management system (SMS in airlines in the framework of implementation of ICAO SARPs that apply methods of risk assessment based on use of operational activity of airline taking into account existing and implementing "protections" or "safety barriers".

  10. 15 CFR 806.9 - Airlines and ship operators.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Airlines and ship operators. 806.9 Section 806.9 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF ECONOMIC ANALYSIS, DEPARTMENT OF COMMERCE DIRECT INVESTMENT SURVEYS § 806.9 Airlines and ship...

  11. New physical model calculates airline crews' radiation exposure

    Science.gov (United States)

    Schultz, Colin

    2013-12-01

    Airline pilots and crews, who spend hundreds of hours each year flying at high altitude, are exposed to increased doses of radiation from galactic cosmic rays and solar energy particles, enough that airline crew members are actually considered radiation workers by the International Commission on Radiological Protection.

  12. Crew coordination concepts: Continental Airlines CRM training

    Science.gov (United States)

    Christian, Darryl; Morgan, Alice

    1987-01-01

    The outline of the crew coordination concepts at Continental airlines is: (1) Present relevant theory: Contained in a pre-work package and in lecture/discussion form during the work course, (2) Discuss case examples: Contained in the pre-work for study and use during the course; and (3) Simulate practice problems: Introduced during the course as the beginning of an ongoing process. These concepts which are designed to address the problem pilots have in understanding the interaction between situations and their own theories of practice are briefly discussed.

  13. Komparativ analyse - Scandinavian Airlines & Norwegian Air Shuttle

    OpenAIRE

    Kallesen, Martin Nystrup; Singh, Ravi Pal; Boesen, Nana Wiaberg

    2017-01-01

    The project is based around a pondering of how that a company the size of Scandinavian Airlines or Norwegian Air Shuttle use their Finances and how they see their external environment. This has led to us researching the relationship between the companies and their finances as well as their external environment, and how they differ in both.To do this we have utilised a myriad of different methods to analyse the companies, including PESTEL, SWOT, TOWS; DCF, risk analysis, Sensitivity, Porter’s ...

  14. Cosmic radiation exposure to airline flight passenger

    International Nuclear Information System (INIS)

    Momose, Mitsuhiro

    2000-01-01

    At the high altitudes, airline flight passengers can be exposed to some levels of cosmic radiation. The purpose of this study was to quantify this radiation exposure. Cosmic radiation was measured during 5 flights using a personal dosimeter (PDM-102, Aloka). Cosmic radiation equivalent dose rates ranged from 0.7 to 1.43 microsieverts per hour, the average rate was 1.08. For the passenger who travels only occasionally, the cosmic radiation levels are well below occupational limits, and the risks are extremely small. (author)

  15. AIRLINE ACTIVITY FORECASTING BY REGRESSION MODELS

    Directory of Open Access Journals (Sweden)

    Н. Білак

    2012-04-01

    Full Text Available Proposed linear and nonlinear regression models, which take into account the equation of trend and seasonality indices for the analysis and restore the volume of passenger traffic over the past period of time and its prediction for future years, as well as the algorithm of formation of these models based on statistical analysis over the years. The desired model is the first step for the synthesis of more complex models, which will enable forecasting of passenger (income level airline with the highest accuracy and time urgency.

  16. Cosmic radiation exposure to airline flight passenger

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Mitsuhiro [Shinshu Univ., Matsumoto, Nagano (Japan). School of Medicine

    2000-08-01

    At the high altitudes, airline flight passengers can be exposed to some levels of cosmic radiation. The purpose of this study was to quantify this radiation exposure. Cosmic radiation was measured during 5 flights using a personal dosimeter (PDM-102, Aloka). Cosmic radiation equivalent dose rates ranged from 0.7 to 1.43 microsieverts per hour, the average rate was 1.08. For the passenger who travels only occasionally, the cosmic radiation levels are well below occupational limits, and the risks are extremely small. (author)

  17. The Role of Budget Airlines in the Air Transport Market

    Directory of Open Access Journals (Sweden)

    Panasiuk Irina P.

    2017-05-01

    Full Text Available The contemporary air transport market has been considered and analyzed, key aspects of the emergence of budget airlines (low-cost in the air transport market have been highlighted. The main factors of influence on their functioning and international distribution have been allocated. On exploring the air transport market, it can be argued that low-cost airlines are gaining speed and spreading all around the world. This system was developed specifically for budget tourists and is particularly popular among students. Budget airlines are a profitable alternative to expensive airfares. As a rule, low-cost airlines refuse most traditional services to reduce the cost of transporting passengers, and hence the prices of flights. In the current phase of operation of the budget airlines, it is particularly necessary to study the reasons for such charity and the efficiency factor in providing cheap airfares. In spite of the tempting offer, there are some nuances that are subject of research.

  18. Sentimental Analysis for Airline Twitter data

    Science.gov (United States)

    Dutta Das, Deb; Sharma, Sharan; Natani, Shubham; Khare, Neelu; Singh, Brijendra

    2017-11-01

    Social Media has taken the world by surprise at a swift and commendable pace. With the advent of any kind of circumstances may it be related to social, political or current affairs the sentiments of people throughout the world are expressed through their help, making them suitable candidates for sentiment mining. Sentimental analysis becomes highly resourceful for any organization who wants to analyse and enhance their products and services. In the airline industries it is much easier to get feedback from astute data source such as Twitter, for conducting a sentiment analysis on their respective customers. The beneficial factors relating to twitter sentiment analysis cannot be impeded by the consumers who want to know the who’s who and what’s what in everyday life. In this paper we are classifying sentiment of Twitter messages by exhibiting results of a machine learning algorithm using R and Rapid Miner. The tweets are extracted and pre-processed and then categorizing them in neutral, negative and positive sentiments finally summarising the results as a whole. The Naive Bayes algorithm has been used for classifying the sentiments of recent tweets done on the different airlines.

  19. European airlines enter the biofuels market. Business Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Van den Heuvel, E.

    2011-06-15

    Biofuels might offer opportunities for achieving improved balance of power to the European airlines in their market environment. The aviation sector in Europe is a high competitive market. It faces high rivalry and increasing fuel costs due to rising oil prices. Moreover, from 2012 the sector will be subject to stringent rules with respect to maximum allowed carbon emissions. Investigating the competitive forces in the aviation sector and executing a strategic group analysis maps the competitors and the major players in the supply chain and the options they have for using alternative fuels for low carbon performance. Both the market and non-market strategies of several European airlines have been studied. It appears that airlines are aiming at first mover advantage by moving upstream in the biofuel value chain. They search for collaboration with other stakeholders to change government regulation to their benefit and influence public opinion and research agendas. Airlines are late entrants in the biofuels market. This research has shown that biofuels can improve the market power balance for European airlines. Biofuels are key to improve the carbon performance of airlines. However, this implies that airlines take position at the resource side of the value chain for biojetfuels. This has the advantage of controlling the security of supply and managing biofuels production complying to ruling sustainability criteria.

  20. Determinants of Profitability in the Airline Industry: A Comparison with Turkish Airlines

    OpenAIRE

    Alahyari, Amirhassan

    2014-01-01

    ABSTRACT: In order to be competitive, the profitability of a firm plays an undeniable role. Therefore, investigation of the factors determining profitability of a firm would provide useful insights for firms in the process of decision making and strategic planning. The airline industry of Turkey has been known as a prominent sector because of its significant contribution to economic development and growth of employment over time. Therefore, the main aim of this study is to investigate the det...

  1. Progress in airline distribution systems: The threat of new entrants to incumbent players

    Directory of Open Access Journals (Sweden)

    Athina Sismanidou

    2009-07-01

    Full Text Available For decades, distribution has been a key ICT (Information and Communication Technology area for airlines and this sector has been dominated by four (now three Global Distribution Systems (GDSs whose primacy has been threatened over the last four years by a set of new players, the so called GDS New Entrants (GNEs.  GNEs emerged with the advent of the Internet and open source technology as ‘disintermediation’ facilitators and generated vast interest from airlines because they promised to reduce the cost of distribution. This paper explores the impact of ICTs on airlines with a focus on GDSs. It provides an overview of the changing market dynamics, analyses the environment that led to the appearance of GNEs and pinpoints the issues behind their until now failure to provide a true alternative to the GDSs.  This analysis complements existing academic research in that it clarifies critical issues in the air travel distribution field and provides an overview of current industry developments.

  2. Airline Maintenance Manpower Optimization from the De Novo Perspective

    Science.gov (United States)

    Liou, James J. H.; Tzeng, Gwo-Hshiung

    Human resource management (HRM) is an important issue for today’s competitive airline marketing. In this paper, we discuss a multi-objective model designed from the De Novo perspective to help airlines optimize their maintenance manpower portfolio. The effectiveness of the model and solution algorithm is demonstrated in an empirical study of the optimization of the human resources needed for airline line maintenance. Both De Novo and traditional multiple objective programming (MOP) methods are analyzed. A comparison of the results with those of traditional MOP indicates that the proposed model and solution algorithm does provide better performance and an improved human resource portfolio.

  3. Application of Core Theory to the Airline Industry

    Science.gov (United States)

    Raghavan, Sunder

    2003-01-01

    Competition in the airline industry has been fierce since the industry was deregulated in 1978. The proponents of deregulation believed that more competition would improve efficiency and reduce prices and bring overall benefits to the consumer. In this paper, a case is made based on core theory that under certain demand and cost conditions more competition can actually lead to harmful consequences for industries like the airline industry or cause an empty core problem. Practices like monopolies, cartels, price discrimination, which is considered inefficient allocation of resources in many other industries, can actually be beneficial in the case of the airline industry in bringing about an efficient equilibrium.

  4. Cancer incidence among Nordic airline cabin crew.

    Science.gov (United States)

    Pukkala, Eero; Helminen, Mika; Haldorsen, Tor; Hammar, Niklas; Kojo, Katja; Linnersjö, Anette; Rafnsson, Vilhjálmur; Tulinius, Hrafn; Tveten, Ulf; Auvinen, Anssi

    2012-12-15

    Airline cabin crew are occupationally exposed to cosmic radiation and jet lag with potential disruption of circadian rhythms. This study assesses the influence of work-related factors in cancer incidence of cabin crew members. A cohort of 8,507 female and 1,559 male airline cabin attendants from Finland, Iceland, Norway and Sweden was followed for cancer incidence for a mean follow-up time of 23.6 years through the national cancer registries. Standardized incidence ratios (SIRs) were defined as ratios of observed and expected numbers of cases. A case-control study nested in the cohort (excluding Norway) was conducted to assess the relation between the estimated cumulative cosmic radiation dose and cumulative number of flights crossing six time zones (indicator of circadian disruption) and cancer risk. Analysis of breast cancer was adjusted for parity and age at first live birth. Among female cabin crew, a significantly increased incidence was observed for breast cancer [SIR 1.50, 95% confidence interval (95% CI) 1.32-1.69], leukemia (1.89, 95% CI 1.03-3.17) and skin melanoma (1.85, 95% CI 1.41-2.38). Among men, significant excesses in skin melanoma (3.00, 95% CI 1.78-4.74), nonmelanoma skin cancer (2.47, 95% CI 1.18-4.53), Kaposi sarcoma (86.0, 95% CI 41.2-158) and alcohol-related cancers (combined SIR 3.12, 95% CI 1.95-4.72) were found. This large study with complete follow-up and comprehensive cancer incidence data shows an increased incidence of several cancers, but according to the case-control analysis, excesses appear not to be related to the cosmic radiation or circadian disruptions from crossing multiple time zones. Copyright © 2012 UICC.

  5. Medications for Sleep Schedule Adjustments in Athletes.

    Science.gov (United States)

    Baird, Matthew B; Asif, Irfan M

    Sleep schedule adjustments are common requirements of modern-day athletes. Many nonpharmacologic and pharmacologic strategies exist to facilitate circadian rhythm shifts to maximize alertness and performance during competition. This review summarizes the evidence for commonly used pharmacologic agents and presents recommendations for the sports medicine provider. MEDLINE searches were performed using the following keywords: sleep aids, circadian rhythm adjustment, athletes and sleep, caffeine and sports, melatonin and athletes, and sleep aids and sports. Pertinent articles were extracted and discussed. Clinical review. Level 2. There are very few available studies investigating pharmacologic sleep aids in athletes. Data from studies involving shift workers and airline personnel are more abundant and were used to formulate recommendations and conclusions. Melatonin, caffeine, and nonbenzodiazepine sleep aids have a role in facilitating sleep schedule changes in athletes and maximizing sports performance through sleep enhancement.

  6. Defense.gov Special Report: Search For Malaysian Airline

    Science.gov (United States)

    Search Navy Ships, Aircraft Enter Fifth Day of Airliner Search U.S. Ships, Planes Join Search for Missing About DOD Leaders Biographies Organization Mission History Frequently Asked Questions Available jobs

  7. Strategic management of a family-owned airline

    DEFF Research Database (Denmark)

    Boyd, Britta; Hollensen, Svend

    2012-01-01

    The concept of absorptive capacity (ACAP) observing a firm’s ability to value, assimilate and utilize new external knowledge is applied in this paper. This case study analysis focuses on strategic management processes and competitiveness of the Cimber Sterling airline. The aim is to discover...... external factors and the strategic management of other selected low-cost airlines. The analysis shows to what extent Cimber Sterling Group A/S as a Danish family business copes with increasing competition and critical situations, such as the volcanic ash cloud and financial crisis. Identifying...... resources and capabilities leading to competitive advantages within the aviation industry. From an ACAP perspective Cimber Sterling Group A/S was analyzed by interviewing selected owners, managers and employees of the airline. A comparison within the airline industry is part of the ACAP concept regarding...

  8. 14 CFR 291.45 - BTS Schedule T-100, U.S. Air Carrier Traffic and Capacity Data by Nonstop Segment and On-Flight...

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false BTS Schedule T-100, U.S. Air Carrier... CARGO OPERATIONS IN INTERSTATE AIR TRANSPORTATION Reporting Rules § 291.45 BTS Schedule T-100, U.S. Air... questions about reporting a joint-service operation, contact the BTS Assistant Director—Airline Information...

  9. An analytical model for the assessment of airline expansion strategies

    Directory of Open Access Journals (Sweden)

    Mauricio Emboaba Moreira

    2014-01-01

    Full Text Available Purpose: The purpose of this article is to develop an analytical model to assess airline expansion strategies by combining generic business strategy models with airline business models. Methodology and approach: A number of airline business models are examined, as are Porter’s (1983 industry five forces that drive competition, complemented by Nalebuff/ Brandenburger’s  (1996 sixth force, and the basic elements of the general environment in which the expansion process takes place.  A system of points and weights is developed to create a score among the 904,736 possible combinations considered. The model’s outputs are generic expansion strategies with quantitative assessments for each specific combination of elements inputted. Originality and value: The analytical model developed is original because it combines for the first time and explicitly elements of the general environment, industry environment, airline business models and the generic expansion strategy types. Besides it creates a system of scores that may be used to drive the decision process toward the choice of a specific strategic expansion path. Research implications: The analytical model may be adapted to other industries apart from the airline industry by substituting the element “airline business model” by other industries corresponding elements related to the different specific business models.

  10. Scheduling the scheduling task : a time management perspective on scheduling

    NARCIS (Netherlands)

    Larco Martinelli, J.A.; Wiers, V.C.S.; Fransoo, J.C.

    2013-01-01

    Time is the most critical resource at the disposal of schedulers. Hence, an adequate management of time from the schedulers may impact positively on the scheduler’s productivity and responsiveness to uncertain scheduling environments. This paper presents a field study of how schedulers make use of

  11. Air crew exposure on board of long-haul flights of the Belgian airlines

    International Nuclear Information System (INIS)

    Verhaegen, F.; Poffijn, A.

    2000-01-01

    New European radiation protection recommendations state that measures need to be taken for flight crew members whose annual radiation exposure exceeds 1 mSv. This will be the case for flight crew members who accumulate most of their flying hours on long-haul flights. The Recommendations for the Implementation of the Basic Safety Standards Directive states that for annual exposure levels between 1 and 6 mSv individual dose estimates should be obtained, whereas for annual exposures exceeding 6 mSv, which might rarely occur, record keeping with appropriate medical surveillance is recommended. To establish the exposure level of Belgian air crews, radiation measurements were performed on board of a total of 44 long-haul flights of the Belgian airlines. The contribution of low linear energy transfer (LET) radiation (photons, electrons, protons) was assessed by using TLD-700H detectors. The exposure to high-LET radiation (mostly neutrons) was measured with bubble detectors. Results were compared to calculations with an adapted version of the computer code CARI. For the low-LET radiation the calculations were found to be in good agreement with the measurements. The measurements of the neutron dose were consistently lower than the calculations. With the current flight schedules used by the Belgian airlines, air crew members are unlikely to receive annual doses exceeding 4 mSv. (author)

  12. Risk factors for fatigue among airline pilots.

    Science.gov (United States)

    van Drongelen, Alwin; Boot, Cécile R L; Hlobil, Hynek; Smid, Tjabe; van der Beek, Allard J

    2017-01-01

    The objective of this study is to determine risk factors for fatigue among airline pilots, taking into account person-, work-, health-, sleep-, and lifestyle-related characteristics. The study population consisted of 502 pilots who participated in the MORE Energy study. Included risk factors were either measured through an online questionnaire or provided by the company. The outcome of this study, fatigue, was assessed using the Checklist Individual Strength (CIS), and was defined as scoring more than 76 points on this questionnaire. The association of the risk factors with fatigue was determined using univariate and multivariate logistic regression analyses. Of the participating pilots, 29.5 % scored more than 76 points on the CIS and were classified as being fatigued. The fully adjusted regression model showed that person-, work-, health-, and lifestyle-related characteristics were associated with fatigue. Pilots who were aged 31 to 40 (OR 3.36, 95 % CI 1.32-8.53) or 41 to 50 (OR 4.19, 95 % CI 1.40-12.47), an evening type (OR 2.40, 95 % CI 1.38-4.16), scored higher on work-life balance disturbance (OR 1.22, 95 % CI 1.10-1.36), scored higher on need for recovery (OR 1.02, 95 % CI 1.01-1.04), scored lower on general health perception (OR 0.31, 95 % CI 0.20-0.47), were less physically active (OR 0.77, 95 % CI 0.66-0.89), and had a moderate alcohol consumption (OR 3.88, 95 % CI 1.21-12.43), were at higher risk for fatigue. Higher age, being an evening type, disturbance of the work-life balance, more need for recovery, a lower perceived health, less physical activity, and moderate alcohol consumption were shown to be risk factors for fatigue. Further longitudinal research is needed to elucidate the direction of the associations found and to evaluate the effects of possible countermeasures in airline pilots.

  13. Multi-day activity scheduling reactions to planned activities and future events in a dynamic model of activity-travel behavior

    Science.gov (United States)

    Nijland, Linda; Arentze, Theo; Timmermans, Harry

    2014-01-01

    Modeling multi-day planning has received scarce attention in activity-based transport demand modeling so far. However, new dynamic activity-based approaches are being developed at the current moment. The frequency and inflexibility of planned activities and events in activity schedules of individuals indicate the importance of incorporating those pre-planned activities in the new generation of dynamic travel demand models. Elaborating and combining previous work on event-driven activity generation, the aim of this paper is to develop and illustrate an extension of a need-based model of activity generation that takes into account possible influences of pre-planned activities and events. This paper describes the theory and shows the results of simulations of the extension. The simulation was conducted for six different activities, and the parameter values used were consistent with an earlier estimation study. The results show that the model works well and that the influences of the parameters are consistent, logical, and have clear interpretations. These findings offer further evidence of face and construct validity to the suggested modeling approach.

  14. CMS multicore scheduling strategy

    International Nuclear Information System (INIS)

    Yzquierdo, Antonio Pérez-Calero; Hernández, Jose; Holzman, Burt; Majewski, Krista; McCrea, Alison

    2014-01-01

    In the next years, processor architectures based on much larger numbers of cores will be most likely the model to continue 'Moore's Law' style throughput gains. This not only results in many more jobs in parallel running the LHC Run 1 era monolithic applications, but also the memory requirements of these processes push the workernode architectures to the limit. One solution is parallelizing the application itself, through forking and memory sharing or through threaded frameworks. CMS is following all of these approaches and has a comprehensive strategy to schedule multicore jobs on the GRID based on the glideinWMS submission infrastructure. The main component of the scheduling strategy, a pilot-based model with dynamic partitioning of resources that allows the transition to multicore or whole-node scheduling without disallowing the use of single-core jobs, is described. This contribution also presents the experiences made with the proposed multicore scheduling schema and gives an outlook of further developments working towards the restart of the LHC in 2015.

  15. An corrigendum on the paper : Solving the job-shop scheduling problem optimally by dynamic programming (Computers and Operations Research 39(12) (2968–2977) (S0305054812000500) (10.1016/j.cor.2012.02.024))

    NARCIS (Netherlands)

    van Hoorn, Jelke J.; Nogueira, Agustín; Ojea, Ignacio; Gromicho Dos Santos, Joaquim Antonio

    2017-01-01

    In [1] an algorithm is proposed for solving the job-shop scheduling problem optimally using a dynamic programming strategy. This is, according to our knowledge, the first exact algorithm for the Job Shop problem which is not based on integer linear programming and branch and bound. Despite the

  16. Robustness of airline alliance route networks

    Science.gov (United States)

    Lordan, Oriol; Sallan, Jose M.; Simo, Pep; Gonzalez-Prieto, David

    2015-05-01

    The aim of this study is to analyze the robustness of the three major airline alliances' (i.e., Star Alliance, oneworld and SkyTeam) route networks. Firstly, the normalization of a multi-scale measure of vulnerability is proposed in order to perform the analysis in networks with different sizes, i.e., number of nodes. An alternative node selection criterion is also proposed in order to study robustness and vulnerability of such complex networks, based on network efficiency. And lastly, a new procedure - the inverted adaptive strategy - is presented to sort the nodes in order to anticipate network breakdown. Finally, the robustness of the three alliance networks are analyzed with (1) a normalized multi-scale measure of vulnerability, (2) an adaptive strategy based on four different criteria and (3) an inverted adaptive strategy based on the efficiency criterion. The results show that Star Alliance has the most resilient route network, followed by SkyTeam and then oneworld. It was also shown that the inverted adaptive strategy based on the efficiency criterion - inverted efficiency - shows a great success in quickly breaking networks similar to that found with betweenness criterion but with even better results.

  17. Industry Consolidation and Future Airline Network Structures in Europe

    Science.gov (United States)

    Dennis, Nigel

    2003-01-01

    In the current downturn in demand for air travel, major airlines are revising and rationalizing their networks in an attempt to improve financial performance and strengthen their defences against both new entrants and traditional rivals. Expansion of commercial agreements or alliances with other airlines has become a key reaction to the increasingly competitive marketplace. In the absence, for regulatory reasons, of cross-border mergers these are the principal means by which the industry can consolidate internationally. This paper analyzes the developments which have been taking place and attempts to itentify the implications for airline network structures and the function of different hub airports. The range of services available to passengers in long-haul markets to/from Europe is evaluated before and after recent industry reorganization. Hubs are crucial to interlink the route networks of parmers in an alliance. However, duplication between nearby hub airports that find themselves within the same airline alliance can lead to loss of service at the weaker locations. The extent to which the alliance hubs in Europe duplicate or complement each other in terms of network coverage is assessed and this methodology also enables the optimal partnerships for "unattached" airlines to be identified. The future role of the various European hubs is considered under different scenarios of global alliance development. The paper concludes by considering possible longer-term developments. In an environment where the low-cost carriers will provide a major element of customer choice, it is suggested that the traditional airlines will retrench around their hubs, surrendering many secondary cities to the low-cost sector. Further reduction in the number of alliances could threaten more of the European hubs. For both regulatory and commercial reasons, the end result may be just one airline alliance - so recreating in the deregulated market the historic rule of IATA.

  18. Prevalence of fatigue in a group of airline pilots.

    Science.gov (United States)

    Reis, Cátia; Mestre, Catarina; Canhão, Helena

    2013-08-01

    Fatigue is a common phenomenon in airline pilots that can impair alertness and ability of crewmembers to safely operate an aircraft and perform safety related tasks. Fatigue can increase the risk of an incident or even an accident. This study provides the first prevalence values for clinically significant fatigue in Portuguese airline pilots. The hypothesis that medium/short-haul pilots may currently present different levels of fatigue than long-haul pilots was also tested. A survey was conducted by requesting Portuguese airline pilots to complete questionnaires placed in the pilots' personal lockers from 1 April until 15 May 2012. The questionnaire included the self-response Fatigue Severity Scale (FSS) to measure subjective fatigue and some additional questions concerning perception of fatigue by pilots. The prevalence values for total and mental fatigue achieved in the Portuguese airline pilots were: 89.3% (FSS > or = 4) and 94.1% (FSS > or = 4) when splitting the sample in two subsamples, long- and medium/short-haul pilots. Levels of total and mental fatigue were higher for medium/short-haul pilots. The analysis of fatigue levels in each type of aviator showed that medium/short-haul pilots presented the highest levels of total and mental fatigue. This study produced the first prevalence values of total and mental fatigue among Portuguese airline pilots, which represents a great step to understanding and addressing this critical phenomenon.

  19. 77 FR 33808 - Agency Information Collection; Activity Under OMB Review: Airline Service Quality Performance...

    Science.gov (United States)

    2012-06-07

    ... DEPARTMENT OF TRANSPORTATION Research & Innovative Technology Administration [Docket ID Number RITA 2008-0002] Agency Information Collection; Activity Under OMB Review: Airline Service Quality.... SUPPLEMENTARY INFORMATION: OMB Approval No. 2138-0041 Title: Airline Service Quality Performance -Part 234. Form...

  20. Assessing the Structure of Non-Routine Decision Processes in Airline Operations Control

    NARCIS (Netherlands)

    Richters, Floor; Schraagen, Johannes Martinus Cornelis; Heerkens, Johannes M.G.

    2015-01-01

    Unfamiliar severe disruptions challenge airline operations control professionals most, as their expertise is stretched to its limits. This study has elicited the structure of airline operations control professionals’ decision process during unfamiliar disruptions by mapping three macrocognitive

  1. Assessing the structure of non-routine decision processes in Airline Operations Control

    NARCIS (Netherlands)

    Richters, F.; Schraagen, J.M.C.; Heerkens, H.

    2015-01-01

    Unfamiliar severe disruptions challenge Airline Operations Control professionals most, as their expertise is stretched to its limits. This study has elicited the structure of Airline Operations Control professionals’ decision process during unfamiliar disruptions by mapping three macrocognitive

  2. Attribute Perception Mapping Services Domestic Airlines Using Correspondence Analysis (59-67

    Directory of Open Access Journals (Sweden)

    Reni Heviandri Riandarini

    2016-06-01

    Full Text Available Positioning analysis provides a better understanding of the position based on the perception of passenger flights to service these attributes attached to each airline. This study aims to perform positioning of the domestic airline services based attributes, which characterize the airline based on the perception of consumers. Correspondence Analysis (CA is used to determine the positioning of the six commercial airlines in Indonesia. The results of correspondence analysis showed that the airline Garuda, Lion Air, Citilink and Air Asia already has its own characteristics inherent in the minds of consumers, while the two other airlines, namely Batik Air and Sriwijaya Air has not had a special identifier.Keywords: Positioning, Correspondence Analysis, Full Service Airline (FSA, Low Fare Airline (LFA

  3. 77 FR 41371 - Proposed Information Collection; Comment Request; Foreign Airline Operators' Revenues and...

    Science.gov (United States)

    2012-07-13

    ... policy questions related to foreign airline operators' revenues and expenses in the United States. There... DEPARTMENT OF COMMERCE Bureau of Economic Analysis Proposed Information Collection; Comment Request; Foreign Airline Operators' Revenues and Expenses in the United States ACTION: Notice. SUMMARY...

  4. The importance of choice attributes and the positions of the airlines ...

    African Journals Online (AJOL)

    1Consumers base their purchase decisions and behaviour on their own ... product, price, place and promotion – should be designed to add up to the .... airline industry, few studies have looked at the attributes affecting domestic airline choice ...

  5. B2B E-marketplaces in the Airline Industry: Process Drivers and Performance indicators

    OpenAIRE

    Wagner, Claudia-Maria; Huber, Bernd; Sweeney, Edward; Smyth, Austin

    2005-01-01

    Competitive pressures are increasing within and between different strategically oriented groups of airlines. This paper focuses on the level of efficiency improvements gained by using e-Marketplaces in the procurement process. Findings from a survey among 88 international airlines reveal that the use of Business-to-Business (B2B) e-Marketplaces does play different roles across the various airline groupings. Airlines that are involved in strategic alliances show higher joint procurement activi...

  6. Public Relations in enhancing brand values: case study Virgin Atlantic and Vietnam Airlines

    OpenAIRE

    Tran Viet, Thang

    2014-01-01

    The ultimate purpose of this dissertation is to evaluate the Public Relations (PR) activities of Vietnam Airlines and give the airline some recommendations to improve its PR performance. In order to achieve this purpose, there are three issues needed to be solved: 1) how PR helps to enhance brand personality and brand values 2) the differences in PR activities between Vietnam Airlines and Virgin Atlantic and 3) what approaches Vietnam Airlines should implement to improve its PR performance. ...

  7. Measuring service quality and a comparative analysis in airline industry

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Izadi

    2013-01-01

    Full Text Available Quality of services in airline industry plays an important role in market penetration and customer retention. In this paper, we present a factor analysis to find important factors in Iranian Airline industry. The study designs a questionnaire consist of 35 questions and distribute it among 200 customers who regularly use services from 16 different airlines and they are investigated based on the implementation of factor analysis. The results of our survey determines seven important factors including physical features of the environment, Kettering, Pre-flight passenger services, Ability to respond, Reliability, Passenger service flight and Virtual Passenger Services. The paper discusses that improving these seven factors can significantly improve service quality in this sector.

  8. Has airline efficiency affected by the inclusion of aviation into European Union Emission Trading Scheme? Evidences from 22 airlines during 2008–2012

    International Nuclear Information System (INIS)

    Li, Ye; Wang, Yan-zhang; Cui, Qiang

    2016-01-01

    We investigate the impacts of including aviation into European Union Emission Trading Scheme on airline efficiency since 2008. Airline efficiency is divided into three stages: Operations Stage, Services Stage and Sales Stage, and Greenhouse Gases Emission is treated as an undesirable output of Services Stage. Two models, Network Slacks-Based Measure with weak disposability and Network Slacks-Based Measure with strong disposability, are established to evaluate the efficiencies of 22 international airlines from 2008 to 2012. The results show that: (1) Most airlines' efficiencies have increased in the period. (2) The average efficiency of European airlines is much higher than that of non-European airlines. (3) The model with weak disposability is more reasonable in distinguishing the airline efficiency while strong disposability is a more reasonable way in treating undesirable outputs. - Highlights: • A new theoretical model of airlines efficiency is built. • Network Slacks-Based Measure models with weak disposability and strong disposability are proposed. • The efficiencies of 22 airlines from 2008 to 2012 are evaluated. • The impacts of including airlines into European Union Emission Trading Scheme are analyzed.

  9. Vulnerability analysis of complementary transportation systems with applications to railway and airline systems in China

    International Nuclear Information System (INIS)

    Ouyang, Min; Pan, ZheZhe; Hong, Liu; He, Yue

    2015-01-01

    Most of existing studies on vulnerability analysis of multiple infrastructure systems mainly focus on negative effects of interdependencies, which mean that failures in one system can propagate to other systems and aggravate the initial damage. In reality, there also exist positive effects of interdependencies, which are shown in complementary systems and mean that if one system fails another system can provide alternative services to satisfy customers' demands. Different types of transportation systems in a city or country are typical complementary systems. Taking railway and airline systems in China as an example, this paper proposes a network-based approach to model the vulnerability of complementary transportation systems, and based on this model, this paper further introduces a dynamic complementary strength metric, which can help decision makers design or select better complementary topologies from the vulnerability perspective. Also, based on a simple genetic algorithm, this paper analyzes whether critical components for single systems are still important when taking two systems as a whole for analysis. Results show that a protection strategy of hardening a few critical components is also good strategy for the combined system. In addition, the findings and several assumptions are further discussed to close the gap between theory and practice. - Highlights: • We propose a method to model and analyze complementary system vulnerability. • We study vulnerability of complementary railway and airline systems in China. • We propose an approach to quantify dynamic complementary strength. • A few critical components for single systems are important for combined system

  10. “A PERSISTENT EXCEPTION TO TEXTBOOK ECONOMICS”: A HISTORICAL OVERVIEW OF INTERNATIONAL AIRLINES

    Directory of Open Access Journals (Sweden)

    Erik Benson

    2005-01-01

    Full Text Available The recent centennial of the Wright Brothers' flight stimulated study of the history of aviation in general and this historical overview of international airlines in particular. International airlines are commercial enterprises, but their history suggests that the economics behind their development was often overridden lypolitical, diplomatic, strategic, imperial, cultural, and emotional pressures. International airlines have not always been economically rational enterprises.

  11. The Effects of Applying Revenue Management on Customer Satisfaction in Airline Industry: An Experimental Study in Indonesia

    Directory of Open Access Journals (Sweden)

    Rambat Lupiyoadi

    2014-06-01

    Full Text Available This research mainly discusses about the effects of applying revenue management, specifically in the contexts of inventory control (variation in ticket prices for the same flight and class and denied boarding (permissibility of reservations exceeding carrying capacity as a hedging practice over the possibility of tickets cancellation on the customers’ satisfaction toward airlines in Indonesia. Ex- perimental method was applied on the research, involving students from University of Indonesia as participants. The results showed that inventory control policy partly affected customer satisfaction, while the denied boarding policy fully affected their satisfaction. These research findings can con- tribute to further studies on consumers’ behaviour in dynamic airlines industry, mainly in emerging markets such as Indonesia.

  12. Risk Analysis for Unintentional Slide Deployment During Airline Operations.

    Science.gov (United States)

    Ayra, Eduardo S; Insua, David Ríos; Castellanos, María Eugenia; Larbi, Lydia

    2015-09-01

    We present a risk analysis undertaken to mitigate problems in relation to the unintended deployment of slides under normal operations within a commercial airline. This type of incident entails relevant costs for the airline industry. After assessing the likelihood and severity of its consequences, we conclude that such risks need to be managed. We then evaluate the effectiveness of various countermeasures, describing and justifying the chosen ones. We also discuss several issues faced when implementing and communicating the proposed measures, thus fully illustrating the risk analysis process. © 2015 Society for Risk Analysis.

  13. Building clusters for CRM strategies by mining airlines customer data

    OpenAIRE

    Miranda, Helena Sofia Guerreiro de

    2013-01-01

    Trabalho de Projeto apresentado como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação As airlines strive to gain market share and sustain profitability in today’s economically challenging environment, they should develop new ways to optimize their frequent flyer programs while increase revenues. Aware of the challenges, airlines want to implement a customer relationship management (CRM) strategy based on customer analytics and data mining ...

  14. Sustainable business models for the state-owned African airlines

    CSIR Research Space (South Africa)

    Ssamula, B

    2009-07-01

    Full Text Available , state-owned airlines, African airlines 1. INTRODUCTION In recent years the civil aviation industry has witnessed rapid corporate, structural and operational changes enabling it to be described as one of the fastest changing sectors within...%), publicly held (19.97%), Port Louis Fund (6.32%), the State Investment Corporation (4.72%), government of Mauritius (4.53%), Rogers and Company (4.28%), British Airways (3.84%), Air France (2.78%) and Air India (2.56%) Morrocco Royal Air Maroc 95...

  15. Strategic Management of a Family-Owned Airline

    DEFF Research Database (Denmark)

    Boyd, Britta; Hollensen, Svend

    2011-01-01

    The concept of absorptive capacity (ACAP) observing a firm’s ability to value, assimilate and utilize new external knowledge is applied in this paper. This comparative study focuses on strategic management processes and competitiveness of different airlines. The aim is to discover differences...... in resources and capabilities leading to competitive advantages within the aviation industry. From a competence and ACAP perspective family and non-family airlines are analysed by interviewing the owners, managers and selected employees of the businesses. The analysis shows how Cimber Sterling Group A...

  16. Model for the growth of the world airline network

    Science.gov (United States)

    Verma, T.; Araújo, N. A. M.; Nagler, J.; Andrade, J. S.; Herrmann, H. J.

    2016-06-01

    We propose a probabilistic growth model for transport networks which employs a balance between popularity of nodes and the physical distance between nodes. By comparing the degree of each node in the model network and the World Airline Network (WAN), we observe that the difference between the two is minimized for α≈2. Interestingly, this is the value obtained for the node-node correlation function in the WAN. This suggests that our model explains quite well the growth of airline networks.

  17. Comparison of different decontaminant delivery methods for sterilizing unoccupied commercial airliner cabins

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi; Chen, Qingyan [National Air Transport Center of Excellence for Research in the Intermodal Transport Environment (RITE), School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47905 (United States)

    2010-09-15

    Effective decontamination is crucial if an airliner cabin is contaminated by biological contaminants, such as infectious disease viruses or intentionally released biological agents. This study used computational fluid dynamics (CFD) method as a tool and vaporized hydrogen peroxide (VHP) as an exemplary decontaminant and Geobacillus stearothermophilus spores as a simulant contaminant to investigate three VHP delivery methods for sterilizing two different airliner cabins. The CFD first determined the airflow and the transient distributions of the contaminant and decontaminant in cabins. Auxiliary equations were implemented into the CFD model for evaluating efficacy of the sterilization process. The improved CFD model was validated by the measured airflow and simulated contaminant distributions obtained from a cabin mockup and the measured efficacy data from the literature. The three decontaminant delivery methods were (1) to supply the mixed VHP and air through the environmental control system of a cabin, (2) to send mixed VHP and air through a front door and to extract them from a back door of a cabin, and (3) to send directly VHP to a cabin and enhance the mixing with air in the cabin by fans. The two air cabins studied were a single-aisle and a twin-aisle airliner one. The results show that the second decontaminant delivery method (displacement method) was the best because the VHP distributions in the cabins were most uniform, the sterilization time was moderate, and the corrosion risk was low. The method displaced the existing air by the air/disinfectant solution, rather than dispersive mixing as the other two methods. (author)

  18. Assessing flight safety differences between the United States regional and major airlines

    Science.gov (United States)

    Sharp, Broderick H.

    During 2008, the U.S. domestic airline departures exceeded 28,000 flights per day. Thirty-nine or less than 0.2 of 1% of these flights resulted in operational incidents or accidents. However, even a low percentage of airline accidents and incidents continue to cause human suffering and property loss. The charge of this study was the comparison of U.S. major and regional airline safety histories. The study spans safety events from January 1982 through December 2008. In this quantitative analysis, domestic major and regional airlines were statistically tested for their flight safety differences. Four major airlines and thirty-seven regional airlines qualified for the safety study which compared the airline groups' fatal accidents, incidents, non-fatal accidents, pilot errors, and the remaining six safety event probable cause types. The six other probable cause types are mechanical failure, weather, air traffic control, maintenance, other, and unknown causes. The National Transportation Safety Board investigated each airline safety event, and assigned a probable cause to each event. A sample of 500 events was randomly selected from the 1,391 airlines' accident and incident population. The airline groups' safety event probabilities were estimated using the least squares linear regression. A probability significance level of 5% was chosen to conclude the appropriate research question hypothesis. The airline fatal accidents and incidents probability levels were 1.2% and 0.05% respectively. These two research questions did not reach the 5% significance level threshold. Therefore, the airline groups' fatal accidents and non-destructive incidents probabilities favored the airline groups' safety differences hypothesis. The linear progression estimates for the remaining three research questions were 71.5% for non-fatal accidents, 21.8% for the pilot errors, and 7.4% significance level for the six probable causes. These research questions' linear regressions are greater than

  19. Stock Investors’ Confidence on Low-Cost and Traditional Airlines in Asia During Financial Crisis 2007-2009 : Evidence from Air Asia and Singapore Airlines

    OpenAIRE

    Goh, Chin Fei; Tay, Karen

    2010-01-01

    The birth of low-cost carriers (LCC) in recent years, have added a new dimension to the aviation business, especially in Asia. There have been several success stories of these LCCs, compared with conventional full-serviced carriers. Two renowned airlines in Asia, Air Asia and Singapore Airlines have been chosen as our sample companies for the purpose of this research paper. Air Asia will represent the LCC segment, while Singapore Airlines is the proxy for traditional carriers. These two class...

  20. Airline Schedule Recovery after Airport Closures: Empirical Evidence since September 11th

    Directory of Open Access Journals (Sweden)

    George Holmes

    2007-06-01

    Full Text Available Esta pesquisa focaliza como é suscetível ao sistema da aviação é a um rompimento do serviço. Quando os estudos precedentes da qualidade do serviço de linha aérea examinarem o vôo atrasados e os cancelamentos sob circunstâncias operacionais normais, este trabalho é um dos primeiros para examinar a qualidade do serviço durante operações irregulares. Desde os ataques do terrorista de 11 de setembro , os fechamentos repetidos do aeroporto devido aos interesses da segurança impuseram custos substanciais aos viajantes, em linhas aéreas, e em agências governamentais, enquanto os vôos são atrasados e/ou cancelados. Usando dados de fechamentos relacionados à segurança do aeroporto desde 11 de setembro , este estudo examina como as linhas aéreas recuperam programações do vôo, uma vez que um aeroporto reabre. Sabendo-se que as rupturas futuras por segurança são prováveis ocorrências, compreender os fatores que determinam a recuperação da programação potencial são importantes. " Na última semana eu anunciei um crackdown por agentes especiais do FAA e inspetor geral do DOT, focalizando lapsos no sistema da segurança operado, comuns, atualmente, nas linhas aéreas. Desde, então, temos parado vôos, fechado, inspecionado, procurado e reaberto nove aeroportos principais, e esvaziado aviões para inspeção de todos os passageiros, quando nós achavamos que os protocolos de segurança das linhas aéreas não tinham seguido procedimentos apropriados." (Secretária do Transporte dos ESTADOS UNIDOS Norman, Mineta, 5 de Novembro , 2001.

  1. Airline Schedule Disruption Management. The impact of flight delays on connection loss

    Directory of Open Access Journals (Sweden)

    Rahil Hicham

    2017-01-01

    Full Text Available Air travel demand is important and many travellers choose to drive to larger airports instead of flying from a small airport for many reasons, especially availability of non-stop flights. Another reason is perceived reliability of service. Consultants have pointed to a large number of delays and cancellations as reasons for low passenger. However, the effect of these flight delays on actual travel times is less clear. Because connections are usually necessary when traveling from small airports, departure delays may lead to missed connections. In the case of a cancellation, need to wait several hours (often overnight for the next flight due to the small number of daily departures. This paper evaluate the impact of delays and cancellations on the profit earned through the seats captured on new opened routes. This aspect of decision-making comes in the form of multi-objective problem by testing the impact of a new opened route in terms of flight delays costs, financial gain and the quality of the service provided to a target customer. The NSGA-II algorithm is adopted to generate a front of Pareto-optimal compound of a number of optimal departure times to the new destination while ensuring the best fill rate, and a minimum flight delays. The experiences are based on the flights of the Royal Air Maroc Company on the Casablanca hub.

  2. Scenario tree airline fleet planning for demand uncertainty

    NARCIS (Netherlands)

    Repko, M.G.J.; Lopes dos Santos, Bruno F.

    2017-01-01

    This paper proposes an innovative multi-period modeling approach to solve the airline fleet planning problem under demand uncertainty. The problem is modeled using a scenario tree approach. The tree is composed of nodes, which represent points of decision in multiple time stages of the planning

  3. Seafloor in the Malaysia Airlines Flight MH370 Search Area

    Science.gov (United States)

    Smith, Walter H. F.; Marks, Karen M.

    2014-05-01

    On the morning of 8 March 2014, Malaysia Airlines flight MH370, from Kuala Lumpur to Beijing, lost contact with air traffic control shortly after takeoff and vanished. While the world waited for any sign of the missing aircraft and the 239 people on board, authorities and scientists began to investigate what little information was known about the plane's actual movements.

  4. Zagreb and Tenerife: Airline Accidents Involving Linguistic Factors

    Science.gov (United States)

    Cookson, Simon

    2009-01-01

    The International Civil Aviation Organization (ICAO) is currently implementing a program to improve the language proficiency of pilots and air traffic controllers worldwide. In justifying the program, ICAO has cited a number of airline accidents that were at least partly caused by language factors. Two accidents cited by ICAO are analysed in this…

  5. 75 FR 41579 - Submitting Airline Data via the Internet

    Science.gov (United States)

    2010-07-16

    ... via the Internet; Final Rule #0;#0;Federal Register / Vol. 75 , No. 136 / Friday, July 16, 2010... Airline Data via the Internet AGENCY: Office of the Secretary, DOT. ACTION: Final rule. SUMMARY: The U.S..., operational and consumer data reports electronically via the Internet using the comma separated value (CSV...

  6. 76 FR 41726 - Reporting Ancillary Airline Passenger Revenues

    Science.gov (United States)

    2011-07-15

    ...., third checked bag or more) Overweight/Oversized Baggage/Sports Equipment Carry-On Baggage 4. In-Flight Medical Equipment 5. In-Flight Entertainment/Internet Access 6. Sleep Sets 7. In-Flight Food/Non Alcoholic... baggage performance is outdated. Airline passengers would [[Page 41728

  7. Mitigation of airspace congestion impact on airline networks

    DEFF Research Database (Denmark)

    Vaaben, Bo Valdemar; Larsen, Jesper

    2015-01-01

    In recent years European airspace has become increasingly congested and airlines can now observe that en-route capacity constraints are the fastest growing source of flight delays. In 2010 this source of delay accounted for 19% of all flight delays in Europe and has been increasing with an average...

  8. The effectiveness of airline pilot training for abnormal events.

    Science.gov (United States)

    Casner, Stephen M; Geven, Richard W; Williams, Kent T

    2013-06-01

    To evaluate the effectiveness of airline pilot training for abnormal in-flight events. Numerous accident reports describe situations in which pilots responded to abnormal events in ways that were different from what they had practiced many times before. One explanation for these missteps is that training and testing for these skills have become a highly predictable routine for pilots who arrive to the training environment well aware of what to expect. Under these circumstances, pilots get plentiful practice in responding to abnormal events but may get little practice in recognizing them and deciding which responses to offer. We presented 18 airline pilots with three abnormal events that are required during periodic training and testing. Pilots were presented with each event under the familiar circumstances used during training and also under less predictable circumstances as they might occur during flight. When presented in the routine ways seen during training, pilots gave appropriate responses and showed little variability. However, when the abnormal events were presented unexpectedly, pilots' responses were less appropriate and showed great variability from pilot to pilot. The results suggest that the training and testing practices used in airline training may result in rote-memorized skills that are specific to the training situation and that offer modest generalizability to other situations. We recommend a more complete treatment of abnormal events that allows pilots to practice recognizing the event and choosing and recalling the appropriate response. The results will aid the improvement of existing airline training practices.

  9. Examining Informal Learning in Commercial Airline Pilots' Communities of Practice

    Science.gov (United States)

    Corns, Kevin M.

    2014-01-01

    A pragmatic sequential mixed methods research methodology was used to examine commercial airline pilots' (N =156) types and frequencies of informal learning activities, perceptions of workplace informal learning, and opinions on how organizations should support workplace informal learning outside of the formal learning environment. This study…

  10. Airline loyalty (programs) across borders : A geographic discontinuity approach

    NARCIS (Netherlands)

    de Jong, Gerben; Behrens, Christiaan; van Ommeren, Jos

    2018-01-01

    We analyze brand loyalty advantages of national airlines in their domestic countries using geocoded data from a major international frequent flier program. We employ a geographic discontinuity design that estimates discontinuities in program activity at the national borders of the program's

  11. Airline's choice of aircraft size-explanations and implications

    NARCIS (Netherlands)

    Rietveld, P.; Givoni, M.

    2009-01-01

    When facing a growth in demand, airlines tend to respond more by means of increasing frequencies than by increasing aircraft size. At many of the world's largest airports there are fewer than 100 passengers per air transport movement, although congestion and delays are growing. Furthermore, demand

  12. Molecular bacterial diversity and bioburden of commercial airliner cabin air

    Energy Technology Data Exchange (ETDEWEB)

    La Duc, M.T.; Stuecker, T.; Venkateswaran, K. [California Inst. of Technology, Pasadena, CA (United States). Jet Propulsion Laboratory, Biotechnology and Planetary Protection Group

    2007-11-15

    Microorganisms that exist in aircraft air systems are considered to be the primary source of microbial contamination that can lead to illness shortly after flying. More than 600 million passengers board commercial airline flights annually in the United States alone. In this study, culture-independent, biomarker-targeted bacterial enumeration and identification strategies were used to estimate total bacterial burden and diversity within the cabin air of commercial airliners. Air-impingement was used to collect samples of microorganisms from 4 flights on 2 commercial carriers. The total viable microbial population ranged from below detection limits to 4.1 x 10{sup 6} cells/m{sup 3} of air. Microbes were found to gradually accumulate from the time of passenger boarding through mid-flight. A sharp decline in bacterial abundance was then observed. Representatives of the {alpha}, {beta} and {gamma} Proteobacteria, as well as Gram-positive bacteria, were isolated in varying abundance. Airline A had large abundances of Neisseria meningitidis rRNA gene sequences and Streptococcus oralis/mitis sequences. Airline B was dominated by pseudomonas synxantha sequences as well as N. meningitidis and S. oralis/mitis. The cabin air samples housed low bacterial diversity and were typically dominated by a particular subset of bacteria, notably opportunistic pathogenic inhabitants of the human respiratory tract and oral cavity. The microbes were found largely around the ventilation ducts and gasper conduits that supply cabin air. 45 refs., 4 tabs., 3 figs.

  13. Airline Transport Pilot-Airplane (Air Carrier) Written Test Guide.

    Science.gov (United States)

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    Presented is information useful to applicants who are preparing for the Airline Transport Pilot-Airplane (Air Carrier) Written Test. The guide describes the basic aeronautical knowledge and associated requirements for certification, as well as information on source material, instructions for taking the official test, and questions that are…

  14. Using the Electronics Development Advantage in Creating a Buzz for the Airline Passengers

    Directory of Open Access Journals (Sweden)

    Bogdan AVRAM

    2013-12-01

    Full Text Available More and more airlines are trying to show their customers their ability to understand their needs, the market trends and the importance of technology in their lives. In response to the rapid development of the consumer electronics, the airline companies focus their attention on offering their customers the possibility to book a flight or check-in using a smartphone, spend time watching movies or be connected to the internet during the flight. Customers search for airlines who are more ”tech-geek” and opened to new technologies, which allows them to rate the airline companies through apps or connect more often with the airline through social-media. Technology has become an important part in developing and marketing the airline services for a better quality, more customer-focused and for better flight experience which ultimately makes the difference when choosing to fly an airline company.

  15. Prevalence of neck pain among cabin crew of Saudi Airlines.

    Science.gov (United States)

    Ezzat, Hesham M; Al-Sultan, Alanood; Al-Shammari, Anwar; Alyousef, Dana; Al-Hamidi, Hager; Al-Dossary, Nafla; Al-Zahrani, Nuha; Al-Abdulqader, Wala

    2015-01-01

    Neck pain is considered to be a major health problem in modern societies. Many previous studies found that certain occupations are related to this problem or are associated with the risk of developing it in future. Although the pain is caused by mechanical factors, it may progress to a serious problem and give rise to other abnormal symptoms such as vertigo, headache, or migraine. To investigate the prevalence of neck pain among the cabin crew of Saudi Airlines. A cross-sectional study was carried out on the available Saudi Airlines cabin crews in King Fahad Airport during our visits, using questionnaires and measurements of several parameters. Neck Pain Questionnaires were distributed to the cabin crews on Saudi Airlines and assessment sheets were completed by all participants of the study to evaluate the prevalence and distribution of neck pain. Physical therapy examination of neck motions in different directions and specific tests were performed by all the participants to identify any symptoms. Using these data the prevalence of neck pain among the cabin crews was calculated. Collected data were analyzed statistically using SPSS software calculating the mean, median, and score of the questionnaire. According to the scoring system of the study, 31 (30.09%) of 105 cabin crew staff of Saudi Airlines had neck pain. Our study confirmed a positive correlation between this occupation and neck pain, and in fact found that according to the results of logistic regression analysis, this occupation is the only significant factor that affects the positive compression test. The prevalence of neck pain among the cabin crews of Saudi Airlines was emphasized. The results show a high prevalence of neck pain in the participants of the study, with most cases appearing to run a chronic - episodic course. Further research is needed to help us understand more about the long-term course of neck pain and its broader outcomes and impacts.

  16. Understanding Consumer Preference Between Low Cost Airlines and Full Service Carriers : A Study on Consumer Choice and Decisions

    OpenAIRE

    Lee, Alex Hoong Onn

    2008-01-01

    The emergence of low cost or no frills airlines in last decade or so have posed considerable threat to the businesses of traditional full service airlines. The competition between the different type of airlines have changed the landscape of the airline industry tremendously and have provided air travelers with options which are unprecedented. The aim of this study is to understand consumer preference between low cost and full service airlines and to determine what are the motivations or facto...

  17. Emergency medicine and the airline passenger

    Science.gov (United States)

    Mohler, S. R.; Nicogossian, A.; Margulies, R. A.

    1980-01-01

    Problems related to immediate medical care in case of in-flight emergencies are discussed with reference to such critical types of medical emergencies as obstructed airway, cardiac dysfunction, trauma, hemorrhage, hypoxia, and pain. It is shown that training flight attendants to deal with in-flight medical emergencies and to use first-aid support equipment and essential and useful drugs may later help with stabilization of a victim and allow continuing the flight to the scheduled destination without the need for a diverted landing. Among the steps suggested in order to upgrade inflight welfare and safety of passengers are the development of an advisory circular by the FAA covering standardized training for flight attendants, regulatory action requiring upgrading of the present rudimentary first-aid kit, and the enactment of Good Samaritan legislation by the U.S. Government.

  18. Agent-based scheduling for aircraft deicing

    NARCIS (Netherlands)

    Mao, X.; Ter Mors, A.W.; Roos, N.; Witteveen, C.

    2006-01-01

    The planning and scheduling of the deicing and anti-icing activities is an important and challenging part of airport departure planning. Deicing planning has to be done in a highly dynamic environment involving several autonomous and self-interested parties. Traditional centralized scheduling

  19. The effect of airline deregulation on automobile fatalities.

    Science.gov (United States)

    Bylow, L F; Savage, I

    1991-10-01

    This paper attempts to quantify the effects of airline deregulation in the United States on intercity automobile travel and consequently on the number of highway fatalities. A demand model is constructed for auto travel, which includes variables representing the price and availability of air service. A reduced form model of the airline market is then estimated. Finding that deregulation has decreased airfares and increased flights, it is estimated that auto travel has been reduced by 2.2% per year on average. Given assumptions on the characteristics of drivers switching modes and the types of roads they drove on, the number of automobile fatalities averted since 1978 is estimated to be in the range 200-300 per year.

  20. Measurements of cosmic-ray doses in commercial airline cabins

    International Nuclear Information System (INIS)

    Okano, M.; Fujitaka, K.; Izumo, K.

    1996-01-01

    Cosmic radiation doses which aircrew and air passengers receive in airplanes have been calling attention in many countries especially in the last decade. In this relation, various types of information had been reported on cosmic radiation intensity. In Japan, the cosmic radiation intensity had been measured in commercial airline cabins as well as chartered flights. While the intensity depends on altitude, geomagnetic latitude (or cutoff rigidity), and temporal variation of the solar activity, their doses are often speculated based on paper records on airflights combined with the intensity-altitude relationship. In this study, however, efforts were made to estimate more realistic integrated doses in airline cabins based on actual on-board measurements which had been conducted several dozens of times in each year (e.g., 45 times in 1994 and 27 times in 1995). (author)

  1. Manikin families representing obese airline passengers in the US.

    Science.gov (United States)

    Park, Hanjun; Park, Woojin; Kim, Yongkang

    2014-01-01

    Aircraft passenger spaces designed without proper anthropometric analyses can create serious problems for obese passengers, including: possible denial of boarding, excessive body pressures and contact stresses, postural fixity and related health hazards, and increased risks of emergency evacuation failure. In order to help address the obese passenger's accommodation issues, this study developed male and female manikin families that represent obese US airline passengers. Anthropometric data of obese individuals obtained from the CAESAR anthropometric database were analyzed through PCA-based factor analyses. For each gender, a 99% enclosure cuboid was constructed, and a small set of manikins was defined on the basis of each enclosure cuboid. Digital human models (articulated human figures) representing the manikins were created using a human CAD software program. The manikin families were utilized to develop design recommendations for selected aircraft seat dimensions. The manikin families presented in this study would greatly facilitate anthropometrically accommodating large airline passengers.

  2. Twelve Years in the Life of Airline Websites

    Directory of Open Access Journals (Sweden)

    C. Michael Powell

    2016-04-01

    Full Text Available Perhaps no innovation in history has affected marketing management as pervasively as has the advent of e-commerce. This revolutionary new channel has required businesses to acquire an entirely new set of skills and approaches to promotion, pricing, and distribution. The necessity for e-commerce website operators to more deeply understand consumer behavior when engaged in e-commerce has become a central and crucial factor in website success or failure. As predicted nearly 20 years ago, travel bookings have moved almost entirely to the World Wide Web (WWW. For the past 12 years, data have been collected concerning traveler’s preferences, concerns, and perceptions of airline websites in particular. This research reviews and comments on the evolution of those sites and consumer perceptions of efficiency, ease of use, and usefulness. The results of this study are intended to guide airlines in their pursuit of customer satisfaction and increased profits.

  3. The evolving network structure of US airline system during 1990-2010

    Science.gov (United States)

    Lin, Jingyi; Ban, Yifang

    2014-09-01

    This paper analyzes the growth and evolution of topological features of the US airline network over a 20-year period. It captures the change in the network system from different dimensions of complex networks such as centrality distribution and various structural properties of the network over time. We first illustrate the results of a set of measures, including degree, strength, betweenness centrality, and clustering structure. The geographic features of airport systems, spatial distance and network efficiency are also discussed in this section. In order to further capture the dynamics of the system, this paper also explores the correlation between different measures, and investigates various interactions inside the network. Overall this study offers a novel approach to understanding the growth and evolution of real physical networks.

  4. European Charter Airlines and In-Flight Catering Provision

    OpenAIRE

    Duncan, Tara

    2005-01-01

    This report examines the main UK and European charter airlines. The report will be split into three main sections which correspond to the three main European charter markets, • the UK, • Germany and • Scandinavia/Benelux. Each section considers the current market demand for charter flights before looking more closely at each individual charter carriers. As this report is focussing on charter airline’s onboard catering provision, the report will look at eac...

  5. Mergers and Product Quality: Evidence from the Airline Industry

    OpenAIRE

    Chen, Yongmin; Gayle, Philip

    2013-01-01

    Retrospective studies of horizontal mergers have focused on their price effects, leaving the important question of how mergers affect product quality largely unanswered. This paper empirically investigates this issue for two recent airline mergers: Delta/Northwest and Continental/United. Consistent with the theoretical premise that mergers improve coordination but diminish competitive pressure for quality provision, we find: (i) each merger is associated with a quality increase in markets whe...

  6. Anteseden Customer Loyalty Pada Low Cost Carrier Airline

    OpenAIRE

    Harlan, Marcella

    2015-01-01

    The background of this research was Customer loyalty as a competitive advantage in service industry.The design of this research applies a survey toward unit of analysis on Low Cost Carrier Airline to interview the passanger for testing hypothesis. Meanwhile the required data consist of five variables; Recovery Satisfaction, Corporate Social Responsibility, Customer Trust, Customer Loyalty. The aggregate numbers of customer being respondent of the study are 200. Data analysis us...

  7. Airline service quality evaluation: A review on concepts and models

    OpenAIRE

    Navid Haghighat

    2017-01-01

    This paper reviews different major service quality concept and models which led to great developments in evaluating service quality with focusing on improvement process of the models through discussing criticisms of each model. Criticisms against these models are discussed to clarify development steps of newer models which led to the improvement of airline service quality models. The precise and accurate evaluation of service quality needs utilizing a reliable concept with comprehensive crite...

  8. Relationship between Brazilian airline pilot errors and time of day

    OpenAIRE

    Mello, Marco Tulio de [UNIFESP; Esteves, Andrea Maculano [UNIFESP; Pires, Maria Laura Nogueira [UNIFESP; Santos, Dayane C. [UNIFESP; Bittencourt, Lia Rita Azeredo [UNIFESP; Silva, Rogério Santos [UNIFESP; Tufik, Sergio [UNIFESP

    2008-01-01

    Flight safety is one of the most important and frequently discussed issues in aviation. Recent accident inquiries have raised questions as to how the work of flight crews is organized and the extent to which these conditions may have been contributing factors to accidents. Fatigue is based on physiologic limitations, which are reflected in performance deficits. The purpose of the present study was to provide an analysis of the periods of the day in which pilots working for a commercial airlin...

  9. An analysis of ongoing trends in airline ancillary revenues

    OpenAIRE

    Warnock-Smith, David; O'Connell, John F.; Maleki, Mahnaz

    2017-01-01

    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...

  10. An examination of ongoing trends in airline ancillary revenues

    OpenAIRE

    Warnock-Smith, David; O'Connell, John Frankie; Maleki, Mahnaz

    2015-01-01

    The airline industry seems permanently embedded in producing thin margins and continuously combatting downward pressure on yields. To perpetuate the problem, the industry remains eclipsed with high cost structures and low barriers to entry. However, a new sizzling concept continues to counterbalance these effects in the form of ancillary revenues. Globally, these revenues have increased by 121% from 2010 to 2014 – and the trend is set to continue as carriers are quickly implementing structura...

  11. 77 FR 25105 - Reporting of Ancillary Airline Passenger Revenues

    Science.gov (United States)

    2012-04-27

    ...This document announces a public meeting on a Notice of Proposed Rulemaking (NPRM) issued on July 15, 2011. The NPRM proposed changes regarding reporting of airline ancillary passenger revenues, computation of mishandled baggage rates, and collection of separate statistics for mishandled wheelchairs and scooters used by passengers with disabilities. During the public meeting, DOT staff will provide a summary of the proposals in the NPRM and seek input on costs and benefits associated with the implementation of the proposals.

  12. Cosmic radiation and airline pilots: Exposure pattern as a function of aircraft type

    International Nuclear Information System (INIS)

    Tveten, U.; Haldorsen, T.; Reitan, J.

    2000-01-01

    variation in intensity of the solar radiation, as well as variations in the route schedules of air companies). In the main project these results are subsequently combined with the number of block hours each year for each pilot to generate the individual radiation exposures per year and cumulative over the pilot's career. The end results of the calculations are dose rates per block hour (also referred to as flight hours) for Norwegian pilots employed by SAS, as a function of aircraft type and year. For planes used by the Scandinavian Airline System (SAS) the dose rate ranged from 0.07 μSv.h -1 (Twin Otter, 1975) to 4.3 μSv.h -1 (DC-10, 1975). For a given airplane more moderate, but still significant, differences over time were noticed, i.e. 2.5 μSv.h -1 (DC-10, 1980) and 4.3 μSv.h -1 (DC-10, 1975). (author)

  13. Cosmic radiation and airline pilots: Exposure pattern as a function of aircraft type

    Energy Technology Data Exchange (ETDEWEB)

    Tveten, U.; Haldorsen, T.; Reitan, J

    2000-07-01

    reflect the variation in intensity of the solar radiation, as well as variations in the route schedules of air companies). In the main project these results are subsequently combined with the number of block hours each year for each pilot to generate the individual radiation exposures per year and cumulative over the pilot's career. The end results of the calculations are dose rates per block hour (also referred to as flight hours) for Norwegian pilots employed by SAS, as a function of aircraft type and year. For planes used by the Scandinavian Airline System (SAS) the dose rate ranged from 0.07 {mu}Sv.h{sup -1} (Twin Otter, 1975) to 4.3 {mu}Sv.h{sup -1} (DC-10, 1975). For a given airplane more moderate, but still significant, differences over time were noticed, i.e. 2.5 {mu}Sv.h{sup -1} (DC-10, 1980) and 4.3 {mu}Sv.h{sup -1} (DC-10, 1975). (author)

  14. AsMA Medical Guidelines for Air Travel: Airline Special Services.

    Science.gov (United States)

    Thibeault, Claude; Evans, Anthony D

    2015-07-01

    Medical Guidelines for Airline Travel provide information that enables healthcare providers to properly advise patients who plan to travel by air. Treating physicians should advise patients in need of special services to contact the airline well before travel to find out if the required services will be available. Ensuring the required services are available throughout a journey can be challenging, especially when different airlines and aircraft types are involved. For example, airlines carry a limited supply of oxygen for use in the event of an unexpected in-flight emergency; however, this supply is not intended for use by passengers needing supplemental oxygen. Arrangements must be made in advance with the airline. Therefore, early contact with the airline is helpful.

  15. Strategic Classification and Examination of the Development of Current Airline Alliance Activities

    Science.gov (United States)

    Wang, Zhi H.; Evans, Michael

    2002-01-01

    Previous research argues that despite the fact that strategic alliances have become an important feature of the world airline industry, little rigorous analysis has been done on the effects of these alliances. This is partially because there is a lack of precise definitions to specify different types of airline alliances in the literature. This research identifies several categories of airline alliances through a strategic classification of the current alliance activities involving the major airlines for the period 1989 to 1999. The classification enables this research to examine how strategic alliance activities are evolving, particularly to compare how airlines in North America, the European Union and the Asia Pacific region have committed to different alliances. Findings show that there is a significant difference between the number and scope of alliances adopted in the three aviation markets. These findings facilitate research to further analyse the impact of market liberalization on various formations of strategic airline alliances.

  16. How Do Airlines Perceive That Strategic Alliances Affect Their Individual Branding?

    Science.gov (United States)

    Kalligiannis, Konstantinos; Iatrou, Kostas; Mason, Keith

    2006-01-01

    Much research has been carried out to evaluate the impact of strategic alliance membership on the performance of airlines. However it would be of interest to identify how airlines perceive this impact in terms of branding by each of the three global alliance groupings. It is the purpose of this paper to gather the opinion of airlines, belonging to the three strategic alliance groups, on the impact that the strategic alliance brands have had on their individual brands and how do they perceive that this impact will change in the future. To achieve this, a comprehensive survey of the alliance management and marketing departments of airlines participating in the three global strategic alliances was required. The results from this survey give an indication whether the strategic airline alliances, which are often referred to as marketing agreements, enhance, damage or have no impact on the individual airline brands.

  17. PESTE Analysis of the Romanian National Passenger Airline

    Directory of Open Access Journals (Sweden)

    Pauna Dan

    2011-08-01

    Full Text Available A PESTE analysis is a view over the external environment of a company, business or an economical sector, and it plays an important part in the resource management and in a future decision making process. PESTE analysis places emphasis on the impact of each factor. At international level, different structures, from the governmental ones to well-known companies and not only, choose to analyze the important factors that disturb the good functioning of these entities. In the sector of passengers and freight air transport, the majority of airline operators have chosen to investigate the external environment in which they operate by using analytical methods. For instance, we can mention SWOT and PESTE analysis of the leading low-cost Air Asia, Malaysia's second carrier, that wishes to enter the Australian aviation market, PESTE analysis of Air Arabia - a new company in the Gulf that intends to corner the market of well-known companies such as Emirates Airlines, Gulf Air and Air China. Air Arabia, in order to implement TMQ (Total Management Qualities, has used a PESTE study. In this respect, the approach to monitor the external environment of Tarom national airline is essential in the world economic crisis and globalization activities in the passengers transport, under the conditions of deregulation of the airspace.

  18. Airline service quality evaluation: A review on concepts and models

    Directory of Open Access Journals (Sweden)

    Navid Haghighat

    2017-12-01

    Full Text Available This paper reviews different major service quality concept and models which led to great developments in evaluating service quality with focusing on improvement process of the models through discussing criticisms of each model. Criticisms against these models are discussed to clarify development steps of newer models which led to the improvement of airline service quality models. The precise and accurate evaluation of service quality needs utilizing a reliable concept with comprehensive criteria and effective measurement techniques as the fundamentals of a valuable framework. In this paper, service quality models improvement is described based on three major service quality concepts, the disconfirmation, performance and hierarchical concepts which are developed subsequently. Reviewing various criteria and different measurement techniques such a statistical analysis and multi-criteria decision making assist researchers to have a clear understanding of the development of the evaluation framework in the airline industry. This study aims at promoting reliable frameworks for evaluating airline service quality in different countries and societies due to economic, cultural and social aspects of each society.

  19. Cardiovascular investigations of airline pilots with excessive cardiovascular risk.

    Science.gov (United States)

    Wirawan, I Made Ady; Aldington, Sarah; Griffiths, Robin F; Ellis, Chris J; Larsen, Peter D

    2013-06-01

    This study examined the prevalence of airline pilots who have an excessive cardiovascular disease (CVD) risk score according to the New Zealand Guideline Group (NZGG) Framingham-based Risk Chart and describes their cardiovascular risk assessment and investigations. A cross-sectional study was performed among 856 pilots employed in an Oceania based airline. Pilots with elevated CVD risk that had been previously evaluated at various times over the previous 19 yr were reviewed retrospectively from the airline's medical records, and the subsequent cardiovascular investigations were then described. There were 30 (3.5%) pilots who were found to have 5-yr CVD risk score of 10-15% or higher. Of the 29 pilots who had complete cardiac investigations data, 26 pilots underwent exercise electrocardiography (ECG), 2 pilots progressed directly to coronary angiograms and 1 pilot with abnormal echocardiogram was not examined further. Of the 26 pilots, 7 had positive or borderline exercise tests, all of whom subsequently had angiograms. One patient with a negative exercise test also had a coronary angiogram. Of the 9 patients who had coronary angiograms as a consequence of screening, 5 had significant disease that required treatment and 4 had either trivial disease or normal coronary arteries. The current approach to investigate excessive cardiovascular risk in pilots relies heavily on exercise electrocardiograms as a diagnostic test, and may not be optimal either to detect disease or to protect pilots from unnecessary invasive procedures. A more comprehensive and accurate cardiac investigation algorithm to assess excessive CVD risk in pilots is required.

  20. AIRLINE LOGISTICS AS A PREFERRED GLOBAL LOGISTICS SUPPLY CHAIN WITH REFERENCE TO EXPORTERS IN COIMBATORE DISTRICT

    OpenAIRE

    P. Mani Mekalai; Dr. I. Parvinbanu

    2018-01-01

    Forecast of Airline volume for India made in the report suggests that the domestic and international Airline throughput is expected to grow by eight to ten times the present level in the next twenty years. Catering to the growth of this magnitude would involve expansion of infrastructure facilities, simplification of procedures and adoption of Information Technology/ Automation besides development of Human Resources in the sector. Out of the competitive analysis made on airline logistics serv...

  1. Oil Shocks and Stock Prices of Airlines - An East Asia Perspective

    OpenAIRE

    Lee, Pau Boon

    2005-01-01

    The aim of this dissertation is to study and analyse the impact of oil price shock on the share prices of airline companies in East Asia, in particular international air carriers from Japan, Hong Kong, South Korea, Singapore and Malaysia by looking at how the companies‘ share prices respond to the news of oil shocks. The companies involved in this study were Japan Airlines ("JAL"), All Nippon Airways ("ANA"), Cathay Pacific Airways ("Cathay"), Korean Air ("KAL"), Malaysian Airlines ("MAS") an...

  2. Building customer relationships as retention strategy in the South African domestic passenger airline industry

    Directory of Open Access Journals (Sweden)

    Pierre Mostert

    2010-12-01

    Full Text Available Organisations are increasingly focusing on building long-term relationships with customers, thereby increasing their probability for success by offering customers higher levels of satisfaction, increasing customer loyalty, and ultimately retaining customers. Airlines in particular can benefit from retaining customers as the airline industry is characterised by fierce competition and many airlines are finding it difficult to survive against the backdrop of enormous challenges in the past decade, including the significant decline in demand for air travel together with rising costs and the worldwide economic downturn. This study investigates the effect which a strategy by airlines of building relationships with customers has on customer satisfaction, loyalty, and ultimately customer retention. The effect of service failures on customers' relationships with airlines are also considered as a negative experience could results in customers defecting to competitors. A questionnaire, comprising six sections, was specifically compiled to determine customer retention in the South African domestic passenger airline industry. Data were collected by trained fieldworkers from OR Tambo International Airport by means of a non-probability convenience sampling method from 324 passengers flying with the various domestic airlines. Findings indicate that most respondents were satisfied with the airlines' overall service; respondents who formed relationships with domestic airlines were more loyal toward the airlines; and the relationships of respondents who were satisfied with airlines' service recovery efforts were either strengthened or unchanged. The findings from this study support findings from international studies by providing a unique South African perspective on the effect of a strategy of building relationships with customers on their satisfaction, loyalty and ultimately retention. It can therefore be recommended that the organisations competing in the South

  3. Interplay between air passengers' service quality, satisfaction, loyalty and loyalty programmes in South African owned airlines

    OpenAIRE

    Mantey, Nicholas O.; Naidoo, Vannie

    2017-01-01

    Orientation: Delivering service quality is crucial for the continuous operation and sustainability of South African owned airlines. The term ‘South African owned airlines’ refers to six South African owned registered airlines, and is used for purpose of anonymity and confidentiality. Research purpose: The main aim of this study was to examine the interplay between service quality delivery, satisfaction, loyalty programmes and passengers’ loyalty to South African owned airlines. Motivati...

  4. An integrated marketing approach for a medium-sized South African airline in a deregulated market

    OpenAIRE

    2012-01-01

    M.Comm. The overall goal of this study is to provide a medium-sized South African airline with the theoretical framework and necessary research and analyses, in developing an integrated marketing approach in a deregulated environment. The objectives of the study are : to analyse the macro and market variables that could impact on the marketing efforts of a medium-sized South African airline. to assess a medium-sized South African airline's marketing efforts (in response to external variabl...

  5. Measuring Strategic Firm Interaction in Product-Quality Choices: The Case of Airline Flight Frequency

    OpenAIRE

    Jan K. Brueckner; Dan Luo

    2013-01-01

    This paper investigates strategic interaction among airlines in product-quality choices. Using an instrumental variables approach, the paper estimates flight-frequency reaction functions, which relate an airline’s frequency on a route to its own characteristics and to the frequencies of competing airlines. A positive reaction function slope is found in some cases, indicating the presence of strategic interaction in the choice of frequencies. The paper also asks whether multimarket contact g...

  6. Bankruptcy and Product-Market Competition: Evidence from the Airline Industry

    OpenAIRE

    Ciliberto, Federico; Schenone, Carola

    2010-01-01

    We investigate the effects of Chapter 11 bankruptcy filings on product market competition using data from the US airline industry. We find that bankrupt airlines permanently downsize their national route structure, their airport-specific networks, and their route-specific flight frequency and capacity. We also find that bankrupt airlines lower their route-specific prices while under bankruptcy protection, and increase them after emerging. We do not find robust evidence of significant changes ...

  7. Price rules in airline marketing / Elina Krauja-Veide, Marina Jõgi, Toms Andersons...[jt.

    Index Scriptorium Estoniae

    2004-01-01

    Lennukompaniide Air Baltic, Estonian Air, British Airways ja Lithuanian Airlines turundusjuhid olukorrast Baltimaade lennundusturul ja lennufirmade turundustegevusest. Kommenteerivad Priit Kivik, Ilona Kbejan, Julia Brjuhanova. Tabel

  8. Marketing implications of loyalty programs on customer relationship management within the airline industry

    Directory of Open Access Journals (Sweden)

    Karamata Ema

    2017-01-01

    Full Text Available One of the most remarkable tendencies on the market of airline services is that nowadays almost every airline company strive to build long-term relationships with customers/users of airline services through loyalty programs. The subject of the paper is to explore the role of Frequent Flyer Programs (FFPs in the scope of customer relationship management in airline industry and to determine whether affiliation to FFPs affects customers to buy tickets from the same airline carrier. For this purpose, an empirical analysis was conducted based on the data obtained from the survey conducted at the Belgrade airport Nikola Tesla, in September 2015. Hypothesis is formed in accordance with the stated aim of the work and was tested by using descriptive and graphical presentation as well as Chi-square statistical test. The results have shown that loyalty programs influence customers when choosing airlines, meaning that Frequent Flyer members tend to use air transportation services of airline carriers which are part of Frequent Flyer Program they belong to, whenever price and timing suit them. Furthermore, the chance of choosing the airline whose Frequent Flyer Program one is member of, increases proportionally to the length of membership and, more importantly, the number of flights that one has realized so far. Based on the tested hypothesis and observed preferences of the travelers, possible marketing implications of the results are pointed out in this article, as well as the analysis of the status and rating of our national airline according to surveyed passengers.

  9. AirAsia In The Malaysian Domestic Airline Market: Empirical Analysis Of Strategy

    OpenAIRE

    Mok Kim Man; Jainurin Bin Justine

    2011-01-01

    This paper will examine the results of the strategic actions of AirAsia in the Malaysian domestic airline market. Firstly, the paper will provide a general background of the airline industry, in particular the Malaysian domestic airline market and a summary of an analysis of the industry using Michael Porters Five Forces Analysis. Secondly, the paper will provide a brief background of AirAsia and Malaysia Airlines. Thirdly, the paper will analyse the results of AirAsias strategy vis--vis oper...

  10. Baseline energy forecasts and analysis of alternative strategies for airline fuel conservation

    Energy Technology Data Exchange (ETDEWEB)

    1976-07-01

    To evaluate the impact of fuel conservation strategies, baseline forecasts of airline activity and energy consumption to 1990 were developed. Alternative policy options to reduce fuel consumption were identified and analyzed for three baseline levels of aviation activity within the framework of an aviation activity/energy consumption model. By combining the identified policy options, a strategy was developed to provide incentives for airline fuel conservation. Strategies and policy options were evaluated in terms of their impact on airline fuel conservation and the functioning of the airline industry as well as the associated social, environmental, and economic costs. (GRA)

  11. The Study of Airline Merger and Acquisition in the Great China Area

    Science.gov (United States)

    Shon, Zhengyi

    2003-01-01

    The Asian financial crisis in the late 20 th century has some long lasting effect on the air transportation industry in Asia, especially in the Great China Area. Starting from 1998, airlines in both China and Taiwan suffered some serious financial losses due to the diminishing travel demand caused by the economic recession. Airlines were forced to cut price to attract passengers and hence crashed the market discipline. A number of airline mergers and acquisitions were then driven by the markets and the governments. After China and Taiwan have both entered the World Trade Organization, some mega-merging cases were finalized in late 2002 for better fitting the world's aviation competitions. This paper reviews the nine merging and acquiring cases in the Great China Area in the past 5 years. Almost all the airlines in the area were involved. The new groups of airlines and the survival airlines are introduced. Market response to the airline mergers will also be examined. A general look over the performance of the new airlines will be discussed. And the future of the market will also be analyzed. Finally, the practices and the impacts of current inter-state mergers in the Great China Area will be examined. The study has expected a highly concentrated domestic market in both China and Taiwan. Each of the market will be dominated by three major airline groups of their own. Cross-holding equity within these 6 leading aviation groups would also be possible after further deregulations.

  12. Immunization Schedules for Adults

    Science.gov (United States)

    ... ACIP Vaccination Recommendations Why Immunize? Vaccines: The Basics Immunization Schedule for Adults (19 Years of Age and ... diseases that can be prevented by vaccines . 2018 Immunization Schedule Recommended Vaccinations for Adults by Age and ...

  13. Instant Childhood Immunization Schedule

    Science.gov (United States)

    ... Recommendations Why Immunize? Vaccines: The Basics Instant Childhood Immunization Schedule Recommend on Facebook Tweet Share Compartir Get ... date. See Disclaimer for additional details. Based on Immunization Schedule for Children 0 through 6 Years of ...

  14. Planning fuel-conservative descents in an airline environmental using a small programmable calculator: algorithm development and flight test results

    Energy Technology Data Exchange (ETDEWEB)

    Knox, C.E.; Vicroy, D.D.; Simmon, D.A.

    1985-05-01

    A simple, airborne, flight-management descent algorithm was developed and programmed into a small programmable calculator. The algorithm may be operated in either a time mode or speed mode. The time mode was designed to aid the pilot in planning and executing a fuel-conservative descent to arrive at a metering fix at a time designated by the air traffic control system. The speed model was designed for planning fuel-conservative descents when time is not a consideration. The descent path for both modes was calculated for a constant with considerations given for the descent Mach/airspeed schedule, gross weight, wind, wind gradient, and nonstandard temperature effects. Flight tests, using the algorithm on the programmable calculator, showed that the open-loop guidance could be useful to airline flight crews for planning and executing fuel-conservative descents.

  15. User interface issues in supporting human-computer integrated scheduling

    Science.gov (United States)

    Cooper, Lynne P.; Biefeld, Eric W.

    1991-01-01

    The topics are presented in view graph form and include the following: characteristics of Operations Mission Planner (OMP) schedule domain; OMP architecture; definition of a schedule; user interface dimensions; functional distribution; types of users; interpreting user interaction; dynamic overlays; reactive scheduling; and transitioning the interface.

  16. Web Publishing Schedule

    Science.gov (United States)

    Section 207(f)(2) of the E-Gov Act requires federal agencies to develop an inventory and establish a schedule of information to be published on their Web sites, make those schedules available for public comment. To post the schedules on the web site.

  17. Preemptive scheduling with rejection

    NARCIS (Netherlands)

    Hoogeveen, H.; Skutella, M.; Woeginger, Gerhard

    2003-01-01

    We consider the problem of preemptively scheduling a set of n jobs on m (identical, uniformly related, or unrelated) parallel machines. The scheduler may reject a subset of the jobs and thereby incur job-dependent penalties for each rejected job, and he must construct a schedule for the remaining

  18. Preemptive scheduling with rejection

    NARCIS (Netherlands)

    Hoogeveen, J.A.; Skutella, M.; Woeginger, G.J.; Paterson, M.

    2000-01-01

    We consider the problem of preemptively scheduling a set of n jobs on m (identical, uniformly related, or unrelated) parallel machines. The scheduler may reject a subset of the jobs and thereby incur job-dependent penalties for each rejected job, and he must construct a schedule for the remaining

  19. Outage scheduling and implementation

    International Nuclear Information System (INIS)

    Allison, J.E.; Segall, P.; Smith, R.R.

    1986-01-01

    Successful preparation and implementation of an outage schedule and completion of scheduled and emergent work within an identified critical path time frame is a result of careful coordination by Operations, Work Control, Maintenance, Engineering, Planning and Administration and others. At the Fast Flux Test Facility (FFTF) careful planning has been responsible for meeting all scheduled outage critical paths

  20. Scheduling with Time Lags

    NARCIS (Netherlands)

    X. Zhang (Xiandong)

    2010-01-01

    textabstractScheduling is essential when activities need to be allocated to scarce resources over time. Motivated by the problem of scheduling barges along container terminals in the Port of Rotterdam, this thesis designs and analyzes algorithms for various on-line and off-line scheduling problems

  1. Analysis of airlines operative in Spain environmental dimensions: a review of their web site content; Analisis de la dimension medioambiental de las companias aereas que operan en Espana: estudio del contenido de sus paginas web

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Bustamante Yabar, D. C.; Rodriguez Herraez, B.; Medrano Garcia, M. L.

    2011-07-01

    Tourism is a significant economic sector since the economic and social development of Spain points of view. Within, airlines are crucial due to it accounts for the highest share on international tourists transport mean selection. Airlines produce a significant percentage of total pollution mostly atmospheric and acoustic, that should be reduced because their volume and rhythm of increase are unsustainable from the global perspective and also for sustainable development aims and environmental protection policies, particularly the E.U policies. Therefore, airlines are progressing nowadays through Social Corporative Responsibility policies which emphasize their business environmental dimension. It is relevant to analyze those firm SCR dynamics in order to obtain conclusions on the structural and functional systems drivers of change since the social economic and political perspectives and its relations to sustain ability; also in terms to their collaboration to socioeconomic and environmental basic equilibrium maintenance. (Author)

  2. NASA scheduling technologies

    Science.gov (United States)

    Adair, Jerry R.

    1994-01-01

    This paper is a consolidated report on ten major planning and scheduling systems that have been developed by the National Aeronautics and Space Administration (NASA). A description of each system, its components, and how it could be potentially used in private industry is provided in this paper. The planning and scheduling technology represented by the systems ranges from activity based scheduling employing artificial intelligence (AI) techniques to constraint based, iterative repair scheduling. The space related application domains in which the systems have been deployed vary from Space Shuttle monitoring during launch countdown to long term Hubble Space Telescope (HST) scheduling. This paper also describes any correlation that may exist between the work done on different planning and scheduling systems. Finally, this paper documents the lessons learned from the work and research performed in planning and scheduling technology and describes the areas where future work will be conducted.

  3. Online Scheduling in Manufacturing A Cumulative Delay Approach

    CERN Document Server

    Suwa, Haruhiko

    2013-01-01

    Online scheduling is recognized as the crucial decision-making process of production control at a phase of “being in production" according to the released shop floor schedule. Online scheduling can be also considered as one of key enablers to realize prompt capable-to-promise as well as available-to-promise to customers along with reducing production lead times under recent globalized competitive markets. Online Scheduling in Manufacturing introduces new approaches to online scheduling based on a concept of cumulative delay. The cumulative delay is regarded as consolidated information of uncertainties under a dynamic environment in manufacturing and can be collected constantly without much effort at any points in time during a schedule execution. In this approach, the cumulative delay of the schedule has the important role of a criterion for making a decision whether or not a schedule revision is carried out. The cumulative delay approach to trigger schedule revisions has the following capabilities for the ...

  4. Identifying Characteristics of Airline Frequent-Fliers in Australia: Implications for Market Segmentation, Target Marketing, and Product Differentiation

    Science.gov (United States)

    1998-01-01

    Airlines can cultivate new business, enjoy repeat patronage through progressively attractive awards given directly to frequent fliers, deter emerging airlines from entering established markets, and compile the demographic profiles and travel characte...

  5. Integration of 4D Airline Operation Control Systems into NextGen and the NAS, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — WxOps patent pending OpsTablet(TM) software and 4D geospatial data are used by Hawaiian Airlines to achieve unprecedented Airline Operation Control (AOC) in a...

  6. Proposing a framework for airline service quality evaluation using Type-2 Fuzzy TOPSIS and non-parametric analysis

    Directory of Open Access Journals (Sweden)

    Navid Haghighat

    2017-12-01

    Full Text Available This paper focuses on evaluating airline service quality from the perspective of passengers' view. Until now a lot of researches has been performed in airline service quality evaluation in the world but a little research has been conducted in Iran, yet. In this study, a framework for measuring airline service quality in Iran is proposed. After reviewing airline service quality criteria, SSQAI model was selected because of its comprehensiveness in covering airline service quality dimensions. SSQAI questionnaire items were redesigned to adopt with Iranian airlines requirements and environmental circumstances in the Iran's economic and cultural context. This study includes fuzzy decision-making theory, considering the possible fuzzy subjective judgment of the evaluators during airline service quality evaluation. Fuzzy TOPSIS have been applied for ranking airlines service quality performances. Three major Iranian airlines which have the most passenger transfer volumes in domestic and foreign flights were chosen for evaluation in this research. Results demonstrated Mahan airline has got the best service quality performance rank in gaining passengers' satisfaction with delivery of high-quality services to its passengers, among the three major Iranian airlines. IranAir and Aseman airlines placed in the second and third rank, respectively, according to passenger's evaluation. Statistical analysis has been used in analyzing passenger responses. Due to the abnormality of data, Non-parametric tests were applied. To demonstrate airline ranks in every criterion separately, Friedman test was performed. Variance analysis and Tukey test were applied to study the influence of increasing in age and educational level of passengers on degree of their satisfaction from airline's service quality. Results showed that age has no significant relation to passenger satisfaction of airlines, however, increasing in educational level demonstrated a negative impact on

  7. The association between airline flight and sinonasal symptoms.

    Science.gov (United States)

    Shargorodsky, Josef; Zheng, Laura; Stillman, Frances; Soong, Andrea; Navas-Acien, Ana; Reh, Douglas

    2016-04-01

    Airplane cabin supply air has been shown to contain multiple possible respiratory irritants. In addition, changes in barometric pressure in flight may contribute to specific respiratory conditions. Therefore, there may be an association between commercial airline flight and sinus disease. Participants of the Secondhand-Smoke, Air Quality and Respiratory Health Among Flight Attendants Study were administered an online questionnaire pertaining to their flight experience and respiratory health. Working years, working days per month, and number of trips per month were quantified, as well as smoking exposure and self-reported physician diagnoses of sinusitis, asthma, and rhinitis. The sinonasal outcomes were quantified using a Respiratory Questionnaire Survey (RQS) score. Multivariable analyses were performed to evaluate the associations between flight time and sinus disease. A total of 579 participants met the inclusion criteria for this study, with cohort prevalence of sinusitis, asthma, and rhinitis of 25.3%, 14.4%, and 20.5%, respectively. Tertiles 2 and 3 of working days per month were associated with higher RQS scores compared to tertile 1 (p for trend <0.01). Individual symptoms significantly associated with increasing number of working days per month included "need to blow nose," "sneezing," and "thick nasal discharge," and the number of international trips per month was significantly associated with "coughing" and "facial pain and pressure," among other symptoms. This is the largest study to analyze the relations between airline flight time and sinonasal disease. The results suggest a possible association between sinusitis diagnosis, symptom scores, and specific sinonasal symptoms, and airline flight time. © 2016 ARS-AAOA, LLC.

  8. 41 CFR 301-10.121 - What classes of airline accommodations are available?

    Science.gov (United States)

    2010-07-01

    ... higher than coach and lower than first-class, in both cost and amenities. This class of accommodation is...-class. The basic class of accommodation by airlines that is normally the lowest fare offered regardless of airline terminology used. For reference purposes only, coach-class may also be referred to by...

  9. 76 FR 4733 - Atlantic Southeast Airlines, a Subsidiary of Skywest, Inc., Airport Customer Service Division...

    Science.gov (United States)

    2011-01-26

    ... Airlines, a Subsidiary of Skywest, Inc., Airport Customer Service Division, Fort Smith, AR; Notice of... Customer Service Division v. United States Secretary of Labor (Court No. 09- 00522). On September 28, 2009... 35. Workers at the subject firm (subject worker group) provided airline customer services. AR 4,8,14...

  10. 75 FR 21716 - Agency Information Collection; Activity Under OMB Review; Airline Service Quality Performance...

    Science.gov (United States)

    2010-04-26

    ... RITA 2008-0002] Agency Information Collection; Activity Under OMB Review; Airline Service Quality... Reports'' pursuant to 14 CFR 234.4 and 234.6. These reports are used to monitor the quality of air service.... SUPPLEMENTARY INFORMATION: OMB Approval No. 2138-0041. Title: Airline Service Quality Performance--Part 234...

  11. 75 FR 41920 - Agency Information Collection; Activity Under OMB Review; Airline Service Quality Performance...

    Science.gov (United States)

    2010-07-19

    ... DEPARTMENT OF TRANSPORTATION Research & Innovative Technology Administration [Docket ID Number RITA 2008-0002] Agency Information Collection; Activity Under OMB Review; Airline Service Quality...: Airline Service Quality Performance--Part 234. Form No.: BTS Form 234. Type Of Review: Re-instatement of...

  12. 77 FR 18306 - Agency Information Collection; Activity Under OMB Review; Airline Service Quality Performance

    Science.gov (United States)

    2012-03-27

    ... 2008-0002] Agency Information Collection; Activity Under OMB Review; Airline Service Quality...'' pursuant to 14 CFR 234.4 and 234.6. These reports are used to monitor the quality of air service that... INFORMATION: OMB Approval No. 2138-0041. Title: Airline Service Quality Performance Reports--Part 234. Form No...

  13. Tinjauan Terhadap Penanganan Bagasi Penumpang Pada Maskapai Malaysia Airlines Di Bandara Internasional Kualanamu

    OpenAIRE

    Atmaja, Wahyu Darma

    2016-01-01

    132204042 Transportasi memiliki posisi yang penting dan strategis dalam pembangunan bangsa untuk mencapai pembangunan nasional. Malaysia Airlines adalah salah satu perusahaan penerbangan yang bergerak dibidang usaha transportasi udara, berupaya untuk meningkatkan jumlah penumpang dengan meningkatkan mutu penanganan bagasi kepada penumpang baik penerbangan domestik maupun penerbangan internasional. Malaysia Airlines memiliki fasilitas bagasi yang disediakan kepada penumpang agar penumpang l...

  14. Spatio-temporal growth pattern and patronage level of airline travel ...

    African Journals Online (AJOL)

    This study assesses the growth pattern of airline travel agencies over a period of forty years across locations in Nigeria as well as the patronage level of agency business. The need for the study arises because of the technological marketing of airline tickets through direct online ticket sales that aims at reducing cost by ...

  15. A non-Gaussian generalisation of the Airline model for robust Seasonal Adjustment

    NARCIS (Netherlands)

    Aston, J.; Koopman, S.J.

    2006-01-01

    In their seminal book Time Series Analysis: Forecasting and Control, Box and Jenkins (1976) introduce the Airline model, which is still routinely used for the modelling of economic seasonal time series. The Airline model is for a differenced time series (in levels and seasons) and constitutes a

  16. Multiple Conceptual Modelling of Perceived Quality of In-flight Airline Services

    Directory of Open Access Journals (Sweden)

    Urban Šebjan

    2017-06-01

    Full Text Available Despite growing literature on the different aspects of airline service quality in relation to behavioural intentions, less attention has been paid to some specific aspects of in-flight services. The focus of the present research is, therefore, on a multiple conceptual model of the quality of in-flight services in relation to passengers’ perception of value, followed by recommendations (word of mouth - WOM of airlines, as well as the quality and comfort of airline seats. The study is performed using two databases of reviewers’/passengers’ opinions regarding the quality of in-flight airline services and airline seat comfort. Our research results reveal that the perceived comfort of the airplane seat is the most important factor of passengers’ perceived quality of in-flight airline services, which also considerably affects the passengers’ perception of value, and consequently moderates behavioural intentions (in our research, expressed through positive WOM. The analysis of the relative importance of the components of perceived airline seats’ comfort shows that seat width is the most significant factor that contributes to the overall perceived comfort of the airline seat.

  17. Reaching new altitudes in e-commerce : Assessing the performance of airline websites

    NARCIS (Netherlands)

    Harison, Elad; Boonstra, Albert

    Many established airlines are attempting to stimulate customers to shift from traditional distribution channels to online channels. To keep improving the quality this important distribution channel is essential for these airlines to have instruments to assess the performance of their websites. This

  18. Performance evaluation of websites using entropy and grey relational analysis methods: The case of airline companies

    Directory of Open Access Journals (Sweden)

    Kemal Vatansever

    2017-07-01

    Full Text Available The revolutionary alterations and conversions occurring in information and communication technologies, have triggered an increase in the electronic commerce applications. Airline tickets are one of the most popular items purchased on the internet. The airline websites have become a big distribution channel for the companies to sustain their competitiveness. At this moment, the competition is increasing as airlines try to acquire and retain customers in the airline industry. To acquire and retain customers in such a highly competitive market, it is important for airlines to understand their relative levels of quality in terms of critical elements affecting their competitive advantages. In this study, an integrated two-stage multi-criteria decision-making techniques were used for the measurement of the performance of the airline websites using the Entropy Weight Method and the Grey Relational Analysis approach. The performance of 11 airline companies’ websites operating in Turkey was evaluated in terms of seven criteria. The data of quality website from airlines websites were taken more than 30 trails on various occasions on different periods of times. The data has been taken from 1 December 2016 to 31 December 2016. The weights of the attributes were calculated by Entropy Weight Method, the evaluation of the alternatives using the Grey Relational Analysis method were given ranking of websites.

  19. Lifestyle factors, direct and indirect costs for a Brazilian airline company

    NARCIS (Netherlands)

    F.M. Rabacow (Fabiana Maluf); O. Do Carmo Luiz (Olinda); A.M. Malik (Ana Maria); A. Burdorf (Alex)

    2014-01-01

    textabstractObjective: To analyze lifestyle risk factors related to direct healthcare costs and the indirect costs due to sick leave among workers of an airline company in Brazil. Methods: In this longitudinal 12-month study of 2,201 employees of a Brazilian airline company, the costs of sick leave

  20. Baseline energy forecasts and analysis of alternative strategies for airline fuel conservation

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    The objectives of this study were to identify measures to reduce airline fuel consumption and to evaluate the impact of these alternatives on fuel consumption through 1990. To evaluate the impact of fuel conservation strategies, baseline forecasts of airline activity and energy consumption to 1990 were developed. Alternative policy options to reduce fuel consumption were identified and analyzed for three baseline levels of aviation activity within the framework of an aviation activity/energy consumption model. By combining the identified policy options, a strategy was developed to provide incentives for airline fuel conservation. Strategies and policy options were evaluated in terms of their impact on airline fuel conservation and the functioning of the airline industry as well as the associated social, environmental, and economic costs. The need for strategies to conserve airline fuel is based on air transportation's dependence upon petroleum; the current lack of alternative energy sources; the potential for disruption of air service due to crises in fuel availability such as experienced during the OPEC oil embargo; and the overall national goal of energy independence through energy conservation in all consuming sectors. The transition from the current situation to that described by strategies and policy options may require difficult adjustments by the airline industry in the short term. In the long term, however, conservation strategies can enhance the health of the airline industry as well as its fuel efficiency.

  1. 22 CFR 102.9 - Arranging for entry and travel of investigating and airline representatives.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Arranging for entry and travel of investigating and airline representatives. 102.9 Section 102.9 Foreign Relations DEPARTMENT OF STATE ECONOMIC AND OTHER FUNCTIONS CIVIL AVIATION United States Aircraft Accidents Abroad § 102.9 Arranging for entry and travel of investigating and airline...

  2. Airline price discrimination : a practice of yield management or customer profiling?

    NARCIS (Netherlands)

    Constantinides, Efthymios; Diercks, Rasha H.J.

    2014-01-01

    Airline ticket prices frequently change, which is usually caused by yield management as price discrimination practice. Recently, buyers of online airline tickets tend to complain about price discrimination based on customer profiling, e.g. by means of cookie data. As cookie data and other directly

  3. A Boolean Approach to Airline Business Model Innovation

    DEFF Research Database (Denmark)

    Hvass, Kristian Anders

    Research in business model innovation has identified its significance in creating a sustainable competitive advantage for a firm, yet there are few empirical studies identifying which combination of business model activities lead to success and therefore deserve innovative attention. This study...... analyzes the business models of North America low-cost carriers from 2001 to 2010 using a Boolean minimization algorithm to identify which combinations of business model activities lead to operational profitability. The research aim is threefold: complement airline literature in the realm of business model...... innovation, introduce Boolean minimization methods to the field, and propose alternative business model activities to North American carriers striving for positive operating results....

  4. THE REGULATION OF DISTANT LABOR RELATIONS AT THE AIRLINES

    Directory of Open Access Journals (Sweden)

    K. S. Ermakov

    2015-01-01

    Full Text Available The article discusses how to optimize airline costs applying the Federal Law of 04.05.2013, № 60-FZ on the regulation of labor relations at the remote aviation enterprises of Russia. Taking into account the changes in the economic system of the country areas of transformation of social and labor issues are identified. A model of assessing the impact of teleworking on the company's profits is suggested. The main features of the activities which are ,most suitable for remote operation are determined.

  5. Cosmic radiation doses at flight level altitudes of airliners

    International Nuclear Information System (INIS)

    Viragh, E.; Petr, I.

    1985-01-01

    Changes are discussed in flux density of cosmic radiation particles with time as are the origin of cosmic radiation, the level of cosmic radiation near the Earth's surface, and the determination of cosmic radiation doses in airliners. Doses and dose rates are given measured on different flight routes. In spite of the fact that the flight duration at an altitude of about 10 km makes for about 80% of the total flight time, the overall radiation burden of the crews at 1000 flight hours a year is roughly double that of the rest of the population. (J.C.)

  6. In-flight radiation measurements aboard French airliners

    International Nuclear Information System (INIS)

    Montagne, C.; Donne, J.P.; Pelcot, D.; Nguyen, V.D.; Bouisset, P.; Kerlau, G.

    1993-01-01

    Routine radiation monitoring has been carried out for more than 15 years aboard Air France airliners. Annual dose received by aircrews can be estimated in the 2-3 mSv range for subsonic long-haul aircrews. Recent dosimetric measurements, using CIRCE devices based on low-pressure TEPC microdosimetry techniques and by using new types of bubble damage detectors, seem to confirm partly these results. More investigations by these new techniques could be undertaken at other phases of the 11 year solar cycle. (author)

  7. Deploying a Route Optimization EFB Application for Commercial Airline Operational Trials

    Science.gov (United States)

    Roscoe, David A.; Vivona, Robert A.; Woods, Sharon E.; Karr, David A.; Wing, David J.

    2016-01-01

    The Traffic Aware Planner (TAP), developed for NASA Langley Research Center to support the Traffic Aware Strategic Aircrew Requests (TASAR) project, is a flight-efficiency software application developed for an Electronic Flight Bag (EFB). Tested in two flight trials and planned for operational testing by two commercial airlines, TAP is a real-time trajectory optimization application that leverages connectivity with onboard avionics and broadband Internet sources to compute and recommend route modifications to flight crews to improve fuel and time performance. The application utilizes a wide range of data, including Automatic Dependent Surveillance Broadcast (ADS-B) traffic, Flight Management System (FMS) guidance and intent, on-board sensors, published winds and weather, and Special Use Airspace (SUA) schedules. This paper discusses the challenges of developing and deploying TAP to various EFB platforms, our solutions to some of these challenges, and lessons learned, to assist commercial software developers and hardware manufacturers in their efforts to implement and extend TAP functionality in their environments. EFB applications (such as TAP) typically access avionics data via an ARINC 834 Simple Text Avionics Protocol (STAP) server hosted by an Aircraft Interface Device (AID) or other installed hardware. While the protocol is standardized, the data sources, content, and transmission rates can vary from aircraft to aircraft. Additionally, the method of communicating with the AID may vary depending on EFB hardware and/or the availability of onboard networking services, such as Ethernet, WIFI, Bluetooth, or other mechanisms. EFBs with portable and installed components can be implemented using a variety of operating systems, and cockpits are increasingly incorporating tablet-based technologies, further expanding the number of platforms the application may need to support. Supporting multiple EFB platforms, AIDs, avionics datasets, and user interfaces presents a

  8. A Mathematical model to predict the US Airlines operation costs and airports charges per route per passenger

    NARCIS (Netherlands)

    Carmona Benitez, R.B.; Lodewijiks, G.

    2010-01-01

    A mathematical model to estimate the average airlines operational costs and airports charges per route is important for airlines companies trying to open new routes and for data generation for other purpose such as transport modeling, simulation modeling, investment analyses for airlines and

  9. Business-IT Alignment Maturity: The Correlation of Performance Indicators and Alignment Maturity within the Commercial Airline Industry

    Science.gov (United States)

    Ryan, Timothy K.

    2010-01-01

    During the period from 1978 to 2009, more than 200 commercial airlines were forced to merge, cease operations, or file for bankruptcy protection. The purpose of this quantitative study is to evaluate the global commercial airline industry from an IT-business alignment perspective and correlate the alignment maturity level of each airline with…

  10. Manpower Projections, Recruitment Needs and Training Requirements for Commercial Airline Pilots in the United States 1968-1979.

    Science.gov (United States)

    Simons, Robert Marchand

    This study evaluated the reported airline pilot shortage in relation to certified air carriers; recruitment needs for qualified applicants; training requirements as recommended by air carriers, airline captains, and flight officers; and airline pilot supply and demand during 1968-79. A literature review on foreign and domestic pilot shortages was…

  11. Algorithms for classical and modern scheduling problems

    OpenAIRE

    Ott, Sebastian

    2016-01-01

    Subject of this thesis is the design and the analysis of algorithms for scheduling problems. In the first part, we focus on energy-efficient scheduling, where one seeks to minimize the energy needed for processing certain jobs via dynamic adjustments of the processing speed (speed scaling). We consider variations and extensions of the standard model introduced by Yao, Demers, and Shenker in 1995 [79], including the addition of a sleep state, the avoidance of preemption, and variable speed lim...

  12. Scheduling for decommissioning projects

    International Nuclear Information System (INIS)

    Podmajersky, O.E.

    1987-01-01

    This paper describes the Project Scheduling system being employed by the Decommissioning Operations Contractor at the Shippingport Station Decommissioning Project (SSDP). Results from the planning system show that the project continues to achieve its cost and schedule goals. An integrated cost and schedule control system (C/SCS) which uses the concept of earned value for measurement of performance was instituted in accordance with DOE orders. The schedule and cost variances generated by the C/SCS system are used to confirm management's assessment of project status. This paper describes the types of schedules and tools used on the SSDP project to plan and monitor the work, and identifies factors that are unique to a decommissioning project that make scheduling critical to the achievement of the project's goals. 1 fig

  13. Program reference schedule baseline

    International Nuclear Information System (INIS)

    1986-07-01

    This Program Reference Schedule Baseline (PRSB) provides the baseline Program-level milestones and associated schedules for the Civilian Radioactive Waste Management Program. It integrates all Program-level schedule-related activities. This schedule baseline will be used by the Director, Office of Civilian Radioactive Waste Management (OCRWM), and his staff to monitor compliance with Program objectives. Chapter 1 includes brief discussions concerning the relationship of the PRSB to the Program Reference Cost Baseline (PRCB), the Mission Plan, the Project Decision Schedule, the Total System Life Cycle Cost report, the Program Management Information System report, the Program Milestone Review, annual budget preparation, and system element plans. Chapter 2 includes the identification of all Level 0, or Program-level, milestones, while Chapter 3 presents and discusses the critical path schedules that correspond to those Level 0 milestones

  14. Approximating Preemptive Stochastic Scheduling

    OpenAIRE

    Megow Nicole; Vredeveld Tjark

    2009-01-01

    We present constant approximative policies for preemptive stochastic scheduling. We derive policies with a guaranteed performance ratio of 2 for scheduling jobs with release dates on identical parallel machines subject to minimizing the sum of weighted completion times. Our policies as well as their analysis apply also to the recently introduced more general model of stochastic online scheduling. The performance guarantee we give matches the best result known for the corresponding determinist...

  15. Revisiting Symbiotic Job Scheduling

    OpenAIRE

    Eyerman , Stijn; Michaud , Pierre; Rogiest , Wouter

    2015-01-01

    International audience; —Symbiotic job scheduling exploits the fact that in a system with shared resources, the performance of jobs is impacted by the behavior of other co-running jobs. By coscheduling combinations of jobs that have low interference, the performance of a system can be increased. In this paper, we investigate the impact of using symbiotic job scheduling for increasing throughput. We find that even for a theoretically optimal scheduler, this impact is very low, despite the subs...

  16. Factors Affecting Customer Retention in the Airline Industry

    Directory of Open Access Journals (Sweden)

    Raghda Climis

    2017-01-01

    Full Text Available Purpose: This study empirically investigated the factors that affect customer retention in the airline industry in North Cyprus. These factors were service quality attributes, perceived safety, customer satisfaction, loyalty reward program, relationship commitment and customer loyalty. The study also investigated four different groups for purposes of travel (business, education, vacation and family visit in the empirical model. Methodology: A descriptive approach was chosen to conduct this research. A quanhip between customer retention and the related study factors; however, not all of these relations are signifcant. The results also showed that the different purposes of travel had different influences on the variables regarding the positive and signifcant relations between them. Some independent variables had a negative effect on the dependent variables. Conclusions: This research was limited to one group and place: the students of Eastern Mediterranean University in North Cyprus. Originality: This study connected the retention, loyalty, satisfaction and service quality factors as attributes. In addition, this research was the frst to include other independent factors affecting satisfaction and loyalty in a comparison between four different groups regarding the purpose of travel in the airline industry.

  17. Annualized TASAR Benefit Estimate for Alaska Airlines Operations

    Science.gov (United States)

    Henderson, Jeffrey

    2015-01-01

    The Traffic Aware Strategic Aircrew Request (TASAR) concept offers onboard automation for the purpose of advising the pilot of traffic compatible trajectory changes that would be beneficial to the flight. A fast-time simulation study was conducted to assess the benefits of TASAR to Alaska Airlines. The simulation compares historical trajectories without TASAR to trajectories developed with TASAR and evaluated by controllers against their objectives. It was estimated that between 8,000 and 12,000 gallons of fuel and 900 to 1,300 minutes could be saved annually per aircraft. These savings were applied fleet-wide to produce an estimated annual cost savings to Alaska Airlines in excess of $5 million due to fuel, maintenance, and depreciation cost savings. Switching to a more wind-optimal trajectory was found to be the use case that generated the highest benefits out of the three TASAR use cases analyzed. Alaska TASAR requests peaked at four to eight requests per hour in high-altitude Seattle center sectors south of Seattle-Tacoma airport.

  18. Airline Overbooking Problem with Uncertain No-Shows

    Directory of Open Access Journals (Sweden)

    Chunxiao Zhang

    2014-01-01

    Full Text Available This paper considers an airline overbooking problem of a new single-leg flight with discount fare. Due to the absence of historical data of no-shows for a new flight, and various uncertain human behaviors or unexpected events which causes that a few passengers cannot board their aircraft on time, we fail to obtain the probability distribution of no-shows. In this case, the airlines have to invite some domain experts to provide belief degree of no-shows to estimate its distribution. However, human beings often overestimate unlikely events, which makes the variance of belief degree much greater than that of the frequency. If we still regard the belief degree as a subjective probability, the derived results will exceed our expectations. In order to deal with this uncertainty, the number of no-shows of new flight is assumed to be an uncertain variable in this paper. Given the chance constraint of social reputation, an overbooking model with discount fares is developed to maximize the profit rate based on uncertain programming theory. Finally, the analytic expression of the optimal booking limit is obtained through a numerical example, and the results of sensitivity analysis indicate that the optimal booking limit is affected by flight capacity, discount, confidence level, and parameters of the uncertainty distribution significantly.

  19. Alternative Work Schedules: Definitions

    Science.gov (United States)

    Journal of the College and University Personnel Association, 1977

    1977-01-01

    The term "alternative work schedules" encompasses any variation of the requirement that all permanent employees in an organization or one shift of employees adhere to the same five-day, seven-to-eight-hour schedule. This article defines staggered hours, flexible working hours (flexitour and gliding time), compressed work week, the task system, and…

  20. Range Scheduling Aid (RSA)

    Science.gov (United States)

    Logan, J. R.; Pulvermacher, M. K.

    1991-01-01

    Range Scheduling Aid (RSA) is presented in the form of the viewgraphs. The following subject areas are covered: satellite control network; current and new approaches to range scheduling; MITRE tasking; RSA features; RSA display; constraint based analytic capability; RSA architecture; and RSA benefits.

  1. The triangle scheduling problem

    NARCIS (Netherlands)

    Dürr, Christoph; Hanzálek, Zdeněk; Konrad, Christian; Seddik, Yasmina; Sitters, R.A.; Vásquez, Óscar C.; Woeginger, Gerhard

    2017-01-01

    This paper introduces a novel scheduling problem, where jobs occupy a triangular shape on the time line. This problem is motivated by scheduling jobs with different criticality levels. A measure is introduced, namely the binary tree ratio. It is shown that the Greedy algorithm solves the problem to

  2. Hybrid” airlines – Generating value between low-cost and traditional

    Directory of Open Access Journals (Sweden)

    Stoenescu Cristina

    2017-07-01

    Full Text Available Over the last years, the rise of low-cost airlines has determined significant changes in the airline industry and has shaped the evolution of the existing business models. Low-cost airlines started by offering basic services at very low prices; traditional airlines responded by equally cutting costs and reinventing the services offered, with an orientation towards braking down the fare and implementing add-ons, in order to become cost-efficient. As traditional airlines developed strategies to become competitive in this new environment, low-cost airlines started focusing on new ways of enhancing passenger experience and attracting new market segments. As a result, the fragmentation of the market segments addressed by low cost carriers and traditional airlines became less obvious and the characteristics of both business models started to blend at all levels (airline operation, distribution channels, loyalty programs, fleet selection. Thus, this new competition became the foundation of the development of a new „hybrid” carrier, between the low-cost and the traditional models. This article investigates the characteristics of the newly created business model, both from a theoretical perspective and by analysing several case studies. A particular attention will be granted to the evolution of the Romanian carrier Blue Air towards the “hybrid” model. The article focuses on determining the position of the “hybrid” airline in a market with carriers situated along both sides of this business model: lower cost vs. “better” experience and raises the question on how value can be generated in this context. Another aspect tackled is the understanding of the new segmentation of the market, as a consequence of the development of the new business model. In order to achieve this purpose, a survey has been conducted, aiming to mark out the travel preferences of the passengers travelling through the Henri Coandă International Airport.

  3. The Synthesis of a Hardware Scheduler for Non-Manifest Loops

    NARCIS (Netherlands)

    Mansour, O.; Molenkamp, Egbert; Krol, Th.

    This paper addresses the hardware implementation of a dynamic scheduler for non-manifest data dependent periodic loops. Static scheduling techniques which are known to give near optimal scheduling-solutions for manifest loops, fail at scheduling non-manifest loops, since they lack the run time

  4. The strategic capability of Asian network airlines to compete with low-cost carriers

    OpenAIRE

    Pearson, James; O'Connell, John F.; Pitfield, David; Ryley, Tim

    2015-01-01

    Never before have network airlines been so exposed and vulnerable to low-cost carriers (LCCs). While LCCs had 26.3% of all world seats in 2013, Southeast Asia had 57.7% and South Asia 58.4% – and these figures will only increase. There are many consequences of LCCs on network airlines, including inadequately meeting the expectations of customers, so increasing dissatisfaction, and not offering sufficient value-for-money. Clearly, it is fundamentally important for Asian network airlines to res...

  5. Capacity Allocation and Revenue Sharing in Airline Alliances: A Combinatorial Auction-Based Modeling

    Directory of Open Access Journals (Sweden)

    Ying-jing Gu

    2017-01-01

    Full Text Available This paper attempts to establish a framework to help airline alliances effectively allocate their seat capacity with the purpose of maximizing alliances’ revenue. By assuming the airline alliance as the auctioneer and seat capacity in an itinerary as lots, the combinatorial auction model is constructed to optimize the allocation of the seat, and the revenue sharing method is established to share revenue between partners by Vickrey-Clarke-Groves (VCG mechanism. The result of the numerical study shows that the seat capacity allocation is effective even without information exchanging completely and the twofold revenue shares method shows more excitation for the airlines.

  6. An assessment of the expansion strategy followed by Avianca Airlines: Period 2008-2012

    Directory of Open Access Journals (Sweden)

    Mauricio Emboaba Moreira

    2017-04-01

    Full Text Available Purpose: This article aims to apply to the case of Avianca Airlines the Analytical Model for the Assessment of Airline Expansion Strategies developed by Moreira (2014 in order to explain the rationale of the expansion strategy followed by this airline and indicate other possible expansion strategies.  Design/methodology/approach: This article is a case study in the sense that it aims to arrive to broad generalizations based on the collected evidences, focusing on one of the most traditional airlines in the world. This article is a positivist case study, based in the positivist understanding; because it is supported by objective facts of the situation which are informed by the researcher’s interpretive understanding according to it is recommended for this type of study. Findings: The application of the Analytical Model for the Assessment of Airline Expansion Strategies above referred was successful, considering that the model was able to explain a wide range of complex aspects of the Avianca’s development. Thus, being one of the oldest airlines in continued operation in the world, the expansion process of this airline is connected to many political, sociological and economic facets - ie., its general environment - of its mother country, Colombia. The analytical model offered the opportunity to explore these issues in a detailed manner, adding a broader comprehension of this airline that goes beyond its operating and economic analysis. Originality/value: They reside on the fact that this is the first time that this analytical model is applied to study extensively an actual situation. Besides, airlines in Latin America have not been widely covered by the academia and this is an opportunity to begin to fill this gap. Furthermore, the referred analytical model is applicable to organizations or firms that operate in other industries if the proper adjustments are made. Implications: The implications for the academic research are to understand that

  7. International foodborne outbreak of Shigella sonnei infection in airline passengers.

    Science.gov (United States)

    Gaynor, K; Park, S Y; Kanenaka, R; Colindres, R; Mintz, E; Ram, P K; Kitsutani, P; Nakata, M; Wedel, S; Boxrud, D; Jennings, D; Yoshida, H; Tosaka, N; He, H; Ching-Lee, M; Effler, P V

    2009-03-01

    During 22-24 August 2004, an outbreak of Shigella sonnei infection affected air travellers who departed from Hawaii. Forty-seven passengers with culture-confirmed shigellosis and 116 probable cases who travelled on 12 flights dispersed to Japan, Australia, 22 US states, and American Samoa. All flights were served by one caterer. Pulsed-field gel electrophoresis of all 29 S. sonnei isolates yielded patterns that matched within one band. Food histories and menu reviews identified raw carrot served onboard as the likely vehicle of infection. Attack rates for diarrhoea on three surveyed flights with confirmed cases were 54% (110/204), 32% (20/63), and 12% (8/67). A total of 2700 meals were served on flights with confirmed cases; using attack rates observed on surveyed flights, we estimated that 300-1500 passengers were infected. This outbreak illustrates the risk of rapid, global spread of illness from a point-source at a major airline hub.

  8. A Study of Airline Passenger Susceptibility to Atmospheric Turbulence Hazard

    Science.gov (United States)

    Stewart, Eric C.

    2000-01-01

    A simple, generic, simulation math model of a commercial airliner has been developed to study the susceptibility of unrestrained passengers to large, discrete gust encounters. The math model simulates the longitudinal motion to vertical gusts and includes (1) motion of an unrestrained passenger in the rear cabin, (2) fuselage flexibility, (3) the lag in the downwash from the wing to the tail, and (4) unsteady lift effects. Airplane and passenger response contours are calculated for a matrix of gust amplitudes and gust lengths of a simulated mountain rotor. A comparison of the model-predicted responses to data from three accidents indicates that the accelerations in actual accidents are sometimes much larger than the simulated gust encounters.

  9. Food poisoning--a major threat to airline operations.

    Science.gov (United States)

    Burslem, C D; Kelly, M J; Preston, F S

    1990-01-01

    In the spring of 1984, British Airways was involved in a major food poisoning outbreak which affected nearly 1000 passengers, aircrew and ground personnel. The operational impact was worldwide and could have resulted in the cessation of the airline's day-to-day operations. The investigation paralleled a major aircraft disaster in the number of national and international agencies involved and in the variety of disciplines engaged. Although the causative organism was rapidly identified (salmonella), and its introduction into the food chain proved to be a key factor, the scale of the outbreak was the result of an interaction of other factors. As with a major aircraft accident, none of the factors alone would have caused the near disaster that occurred.

  10. Structure and external factors of chinese city airline network

    Science.gov (United States)

    Liu, Hong-Kun; Zhang, Xiao-Li; Zhou, Tao

    2010-08-01

    Abstract We investigate the structural properties of Chinese city airline network (CCAN), where nodes and edges denote cities and direct flights. The degree distribution follows a double power law and a clear hierarchical layout is observed. The population exhibits a weakly positive correlation with the number of flights, yet it does not show obvious correlation with the transportation flow. The distance is an important parameter in CCAN, that is, the number of flights decays fast with the increasing of the distance. In comparison, the tertiary industry has the most important influence on the Chinese air passenger transportation. Statistically speaking, when the tertiary industry value increases by 1%, the next period's volume will increase by 0.73%.

  11. On the treatment of airline travelers in mathematical models.

    Directory of Open Access Journals (Sweden)

    Michael A Johansson

    Full Text Available The global spread of infectious diseases is facilitated by the ability of infected humans to travel thousands of miles in short time spans, rapidly transporting pathogens to distant locations. Mathematical models of the actual and potential spread of specific pathogens can assist public health planning in the case of such an event. Models should generally be parsimonious, but must consider all potentially important components of the system to the greatest extent possible. We demonstrate and discuss important assumptions relative to the parameterization and structural treatment of airline travel in mathematical models. Among other findings, we show that the most common structural treatment of travelers leads to underestimation of the speed of spread and that connecting travel is critical to a realistic spread pattern. Models involving travelers can be improved significantly by relatively simple structural changes but also may require further attention to details of parameterization.

  12. Automatic airline baggage counting using 3D image segmentation

    Science.gov (United States)

    Yin, Deyu; Gao, Qingji; Luo, Qijun

    2017-06-01

    The baggage number needs to be checked automatically during baggage self-check-in. A fast airline baggage counting method is proposed in this paper using image segmentation based on height map which is projected by scanned baggage 3D point cloud. There is height drop in actual edge of baggage so that it can be detected by the edge detection operator. And then closed edge chains are formed from edge lines that is linked by morphological processing. Finally, the number of connected regions segmented by closed chains is taken as the baggage number. Multi-bag experiment that is performed on the condition of different placement modes proves the validity of the method.

  13. Cosmic microwave background science at commercial airline altitudes

    Science.gov (United States)

    Feeney, Stephen M.; Gudmundsson, Jon E.; Peiris, Hiranya V.; Verde, Licia; Errard, Josquin

    2017-07-01

    Obtaining high-sensitivity measurements of degree-scale cosmic microwave background (CMB) polarization is the most direct path to detecting primordial gravitational waves. Robustly recovering any primordial signal from the dominant foreground emission will require high-fidelity observations at multiple frequencies, with excellent control of systematics. We explore the potential for a new platform for CMB observations, the Airlander 10 hybrid air vehicle, to perform this task. We show that the Airlander 10 platform, operating at commercial airline altitudes, is well suited to mapping frequencies above 220 GHz, which are critical for cleaning CMB maps of dust emission. Optimizing the distribution of detectors across frequencies, we forecast the ability of Airlander 10 to clean foregrounds of varying complexity as a function of altitude, demonstrating its complementarity with both existing (Planck) and ongoing (C-BASS) foreground observations. This novel platform could play a key role in defining our ultimate view of the polarized microwave sky.

  14. Addressing the Influence of Space Weather on Airline Navigation

    Science.gov (United States)

    Sparks, Lawrence

    2012-01-01

    The advent of satellite-based augmentation systems has made it possible to navigate aircraft safely using radio signals emitted by global navigation satellite systems (GNSS) such as the Global Positioning System. As a signal propagates through the earth's ionosphere, it suffers delay that is proportional to the total electron content encountered along the raypath. Since the magnitude of this total electron content is strongly influenced by space weather, the safety and reliability of GNSS for airline navigation requires continual monitoring of the state of the ionosphere and calibration of ionospheric delay. This paper examines the impact of space weather on GNSS-based navigation and provides an overview of how the Wide Area Augmentation System protects its users from positioning error due to ionospheric disturbances

  15. NASA Schedule Management Handbook

    Science.gov (United States)

    2011-01-01

    The purpose of schedule management is to provide the framework for time-phasing, resource planning, coordination, and communicating the necessary tasks within a work effort. The intent is to improve schedule management by providing recommended concepts, processes, and techniques used within the Agency and private industry. The intended function of this handbook is two-fold: first, to provide guidance for meeting the scheduling requirements contained in NPR 7120.5, NASA Space Flight Program and Project Management Requirements, NPR 7120.7, NASA Information Technology and Institutional Infrastructure Program and Project Requirements, NPR 7120.8, NASA Research and Technology Program and Project Management Requirements, and NPD 1000.5, Policy for NASA Acquisition. The second function is to describe the schedule management approach and the recommended best practices for carrying out this project control function. With regards to the above project management requirements documents, it should be noted that those space flight projects previously established and approved under the guidance of prior versions of NPR 7120.5 will continue to comply with those requirements until project completion has been achieved. This handbook will be updated as needed, to enhance efficient and effective schedule management across the Agency. It is acknowledged that most, if not all, external organizations participating in NASA programs/projects will have their own internal schedule management documents. Issues that arise from conflicting schedule guidance will be resolved on a case by case basis as contracts and partnering relationships are established. It is also acknowledged and understood that all projects are not the same and may require different levels of schedule visibility, scrutiny and control. Project type, value, and complexity are factors that typically dictate which schedule management practices should be employed.

  16. A Theory of False Cognitive Expectancies in Airline Pilots

    Science.gov (United States)

    Cortes, Antonio I.

    The Theory of False Cognitive Expectancies was developed by studying high reliability flight operations. Airline pilots depend extensively on cognitive expectancies to perceive, understand, and predict actions and events. Out of 1,363 incident reports submitted by airline pilots to the National Aeronautics and Space Administration Aviation Safety Reporting System over a year's time, 110 reports were found to contain evidence of 127 false cognitive expectancies in pilots. A comprehensive taxonomy was developed with six categories of interest. The dataset of 127 false expectancies was used to initially code tentative taxon values for each category. Intermediate coding through constant comparative analysis completed the taxonomy. The taxonomy was used for the advanced coding of chronological context-dependent visualizations of expectancy factors, known as strands, which depict the major factors in the creation and propagation of each expectancy. Strands were mapped into common networks to detect highly represented expectancy processes. Theoretical integration established 11 sources of false expectancies, the most common expectancy errors, and those conspicuous factors worthy of future study. The most prevalent source of false cognitive expectancies within the dataset was determined to be unconscious individual modeling based on past events. Integrative analyses also revealed relationships between expectancies and flight deck automation, unresolved discrepancies, and levels of situation awareness. Particularly noteworthy were the findings that false expectancies can combine in three possible permutations to diminish situation awareness and examples of how false expectancies can be unwittingly transmitted from one person to another. The theory resulting from this research can enhance the error coding process used during aircraft line oriented safety audits, lays the foundation for developing expectancy management training programs, and will allow researchers to proffer

  17. Risk factors for skin cancer among Finnish airline cabin crew.

    Science.gov (United States)

    Kojo, Katja; Helminen, Mika; Pukkala, Eero; Auvinen, Anssi

    2013-07-01

    Increased incidence of skin cancers among airline cabin crew has been reported in several studies. We evaluated whether the difference in risk factor prevalence between Finnish airline cabin crew and the general population could explain the increased incidence of skin cancers among cabin crew, and the possible contribution of estimated occupational cosmic radiation exposure. A self-administered questionnaire survey on occupational, host, and ultraviolet radiation exposure factors was conducted among female cabin crew members and females presenting the general population. The impact of occupational cosmic radiation dose was estimated in a separate nested case-control analysis among the participating cabin crew (with 9 melanoma and 35 basal cell carcinoma cases). No considerable difference in the prevalence of risk factors of skin cancer was found between the cabin crew (N = 702) and the general population subjects (N = 1007) participating the study. The mean risk score based on all the conventional skin cancer risk factors was 1.43 for cabin crew and 1.44 for general population (P = 0.24). Among the cabin crew, the estimated cumulative cosmic radiation dose was not related to the increased skin cancer risk [adjusted odds ratio (OR) = 0.75, 95% confidence interval (CI): 0.57-1.00]. The highest plausible risk of skin cancer for estimated cosmic radiation dose was estimated as 9% per 10 mSv. The skin cancer cases had higher host characteristics scores than the non-cases among cabin crew (adjusted OR = 1.43, 95% CI: 1.01-2.04). Our results indicate no difference between the female cabin crew and the general female population in the prevalence of factors generally associated with incidence of skin cancer. Exposure to cosmic radiation did not explain the excess of skin cancer among the studied cabin crew in this study.

  18. A New Method Based on Simulation-Optimization Approach to Find Optimal Solution in Dynamic Job-shop Scheduling Problem with Breakdown and Rework

    Directory of Open Access Journals (Sweden)

    Farzad Amirkhani

    2017-03-01

    The proposed method is implemented on classical job-shop problems with objective of makespan and results are compared with mixed integer programming model. Moreover, the appropriate dispatching priorities are achieved for dynamic job-shop problem minimizing a multi-objective criteria. The results show that simulation-based optimization are highly capable to capture the main characteristics of the shop and produce optimal/near-optimal solutions with highly credibility degree.

  19. Physician Fee Schedule Search

    Data.gov (United States)

    U.S. Department of Health & Human Services — This website is designed to provide information on services covered by the Medicare Physician Fee Schedule (MPFS). It provides more than 10,000 physician services,...

  20. Clinical Laboratory Fee Schedule

    Data.gov (United States)

    U.S. Department of Health & Human Services — Outpatient clinical laboratory services are paid based on a fee schedule in accordance with Section 1833(h) of the Social Security Act. The clinical laboratory fee...

  1. CERN confirms LHC schedule

    CERN Document Server

    2003-01-01

    The CERN Council held its 125th session on 20 June. Highlights of the meeting included confirmation that the LHC is on schedule for a 2007 start-up, and the announcement of a new organizational structure in 2004.

  2. DMEPOS Fee Schedule

    Data.gov (United States)

    U.S. Department of Health & Human Services — The list contains the fee schedule amounts, floors, and ceilings for all procedure codes and payment category, jurisdication, and short description assigned to each...

  3. Decentralized Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Sørensen, M. D.; Clausen, Jens

    2002-01-01

    scheduling is investigated. The airport terminal is divided into zones, where each zone consists of a set of stands geographically next to each other. Staff is assigned to work in only one zone and the staff scheduling is planned decentralized for each zone. The advantage of this approach is that the staff...... work in a smaller area of the terminal and thus spends less time walking between stands. When planning decentralized the allocation of stands to flights influences the staff scheduling since the workload in a zone depends on which flights are allocated to stands in the zone. Hence solving the problem...... depends on the actual stand allocation but also on the number of zones and the layout of these. A mathematical model of the problem is proposed, which integrates the stand allocation and the staff scheduling. A heuristic solution method is developed and applied on a real case from British Airways, London...

  4. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-11-01

    This single page document is the November 1, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the production reactor.

  5. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-10-01

    This single page document is the October 1, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production Reactor.

  6. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-10-15

    This single page document is the October 15, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production Reactor.

  7. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-09-15

    This single page document is the September 15, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production Reactor.

  8. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-12-15

    This single page document is the December 16, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production reactor.

  9. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-12-01

    This single page document is the December 1, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production reactor.

  10. Fee Schedules - General Information

    Data.gov (United States)

    U.S. Department of Health & Human Services — A fee schedule is a complete listing of fees used by Medicare to pay doctors or other providers-suppliers. This comprehensive listing of fee maximums is used to...

  11. CMS Records Schedule

    Data.gov (United States)

    U.S. Department of Health & Human Services — The CMS Records Schedule provides disposition authorizations approved by the National Archives and Records Administration (NARA) for CMS program-related records...

  12. Disruption Management for an Airline - Rescheduling of aircraft

    DEFF Research Database (Denmark)

    Larsen, Jesper; Løve, Michael; Sørensen, Kim Riis

    2002-01-01

    The Aircraft Recovery Problem (ARP) involves decisions concerning aircraft to flight assignments in situations where unforseen events have disrupted the existing flight schedule, e.g. bad weather causing flight delays. The aircraft recovery problem aims to recover these flight schedules through...... a series of reassignments of aircraft to flights, delaying of flights and cancellations of flights. This article demonstrates an effective method to solve ARP. A heuristic is implemented, which is able to generate feasible revised flight schedules of a good quality in less than 10 seconds. This article...

  13. @doesyourairlinetweet? An empirical examination of the use of twitter by 50 international airlines

    Directory of Open Access Journals (Sweden)

    Lucy Budd

    2012-10-01

    Full Text Available Purpose: To provide empirical evidence of the extent to which 50 of the world’s largest passenger airlines use the social media site twitter.Design/methodology/approach: Original empirical data on the presence and usage of 50 airlines’ official twitter accounts was accessed.Research limitations/implications: Research demonstrates the extent to which airlines are using twitter as a communications tool and suggests that some airline are not currently utilising twitter to its full extent.Practical implications: The research provides information on current twitter use and penetration, thus enabling airlines to benchmark their performance in this social media channel.Originality/value: The paper provides an original empirical insight into a growing phenomenon which is currently underreported in academic literatures.

  14. Fuzzy-VIKOR analysis for customer performance index of civil domestic airline industry in India

    Directory of Open Access Journals (Sweden)

    Suman Saket

    2015-03-01

    Full Text Available This paper considers the factor influencing on an airline carrier based on operations of an airport on the routes flown out of that airport. This study deals with evaluation of the Customer Performance index (CPI of distinct domestic civil airlines in India. CPI consists of various parameters; among them many disembodied parameters, which are difficult to measure. In this context, initially we identified the prime factors that are crucial for evaluation of performances provided by various airlines in India. Thereafter, in order to determine the hierarchy among these factors; modified digital logic (MDL approach is employed and cost is found to be the most important criteria. Furthermore, CPI is calculated using fuzzy-VIKOR approach. Such approaches can help the airlines in re-evaluating their current policies and then formulate comparatively more efficient market strategies to improve performance quality and to gain customers’ loyalty.

  15. Söder Airlines alustab Tampere-Tallinna lende / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2003-01-01

    2002. aastal Soome ärimeeste loodud lennufirma Söder Airlines lennuk hakkab lendama Tallinna ja Tampere vahel, edaspidi kavatsetakse avada ka lennuliin Tampere-Kuressaare. Vt. samas: Lennust Eestisse huvitub ka SkyEurope

  16. Identification and analysis of explanatory variables for a multi-factor productivity model of passenger airlines

    Directory of Open Access Journals (Sweden)

    Antonio Henriques de Araújo Jr

    2011-05-01

    Full Text Available The paper aimed to identify and analyze the explanatory variables for airlines productivity during 2000 2005, by testing the Pearson correlation between the single factor productivity capital, energy and labor of a sample of 45 selected international airlines (4 Brazilian carriers among them and their productivity explanatory variables like medium stage length, aircraft load factor, hours flown and cruise speed for selected routes besides aircraft seat configuration and airlines number of employees. The research demonstrated, that a set of variables can explain differences in productivity for passenger airlines, such as: investment in personnel training processes, automation, airplane seat density, occupation of aircraft, average flight stage length, density and extension of routes, among others.

  17. Vaccines and Airline Travel: A Federal Role to Protect the Public Health.

    Science.gov (United States)

    Robertson, Christopher T

    2016-05-01

    This Article explores two ways in which airline travel is an important vector for the spread of infectious disease, and argues that airlines have market-based and liability-based reasons to require that passengers be vaccinated. Going further, the Article explores whether the federal government has the legal and constitutional authority-especially under the Commerce Clause-to encourage or mandate that airlines implement such a vaccine screen. By disrupting the spread of disease at key network nodes where individuals interact and then connect with other geographic regions, and by creating another incentive for adult vaccination, an airline vaccine screen could be an effective and legally viable tool for the protection of public health.

  18. PROBLEMS OF ROUTE NETWORK AND AIRCRAFT FLEET OPTIMIZATION AS A SPECIFIC TASK OF AIRLINE STRATEGIC PLANNING

    Directory of Open Access Journals (Sweden)

    M. A. Karakuts

    2015-01-01

    Full Text Available The basic problems of route network and aircraft fleet optimization and its role in airline strategic planning are considered. Measures to improve the methods of its implementation are proposed.

  19. Competition, concentration and fares in the U.S. airline industry

    OpenAIRE

    Paul W. Bauer

    1987-01-01

    An examination of the true state of competition and concentration in the airline industry by taking into account the function and effects of the hub-and-spoke networks that have developed in the market.

  20. ATLAS construction schedule

    CERN Multimedia

    Kotamaki, M

    The goal during the last few months has been to freeze and baseline as much as possible the schedules of various ATLAS systems and activities. The main motivations for the re-baselining of the schedules have been the new LHC schedule aiming at first collisions in early 2006 and the encountered delays in civil engineering as well as in the production of some of the detectors. The process was started by first preparing a new installation schedule that takes into account all the new external constraints and the new ATLAS staging scenario. The installation schedule version 3 was approved in the March EB and it provides the Ready For Installation (RFI) milestones for each system, i.e. the date when the system should be available for the start of the installation. TCn is now interacting with the systems aiming at a more realistic and resource loaded version 4 before the end of the year. Using the new RFI milestones as driving dates a new summary schedule has been prepared, or is under preparation, for each system....

  1. [Hygiene in airline catering. I. Microbiologic study of meals distributed on aircrafts].

    Science.gov (United States)

    Castellani, P; Frugoni, G

    1983-08-25

    A preliminary microbiological survey, conducted in the Italian national airlines Catering Department is reported. Precooked,, frozen meals reheated on medium and long distance flights were examined. The results indicate that hygiene standards are satisfactorily maintained. The presence of staphylococcus aureus in some samples highlights the importance of preventive and prophylactic measures in healthy carriers. In view of the growing concern about Salmonella poisoning in airline passengers the absence of this bacterium is extremely satisfying.

  2. The strategic impact of airline group diversification: the cases of Emirates and Lufthansa

    OpenAIRE

    Redpath, N.; O'Connell, John F.; Warnock-Smith, D.

    2016-01-01

    The airline industry is a diverse sector, requiring the support of a varied range of ancillary businesses such as maintenance, catering and travel agencies to carry out its activities. Many of these supporting businesses demonstrate the potential to drive wider profit margins despite generating lower revenues than the airlines themselves, making them attractive investment opportunities in a sector prone to volatile and often lacklustre trading. This study investigates two of the largest diver...

  3. Industry Issue Paper: Cross-Cultural Factors and Corporate Governance Transparency in Global Airline Strategic Alliances

    OpenAIRE

    Giapponi, Catherine C.; Scheraga, Carl A.

    2007-01-01

    This paper argues that a critical dimension in understanding the factors that inhibit the effectiveness and benefits of airline alliances is corporate transparency. Specifically, the issue of transparency in corporate governance is considered. Corporate governance is the set of institutional arrangements affecting corporate decision making, and deals with the relationship among various participants in determining the direction and performance of corporations. However, airline strategic allian...

  4. Radiotystnad resulterar i fullt kaos : En studie om Malaysia Airlines kriskommunikation

    OpenAIRE

    Molander, Agnes; Nässlin Eidenert, Kim

    2014-01-01

    The purpose of this thesis is to study how Malaysia Airlines communicated during the two largest crises of 2014. Key questions to be answered are: Did organizational hypocrisy occur? If yes, in what way? Which communication strategies were used? Did the company mediate an unequivocal message and how was the information framed? Did any aggravating factors, which worsened the organization’s reputation, appear? How did Malaysia Airlines manage possible rumours? Was the word contact used as a key...

  5. Development of the Mathematical Model of Integrated Management System for an Airline

    Directory of Open Access Journals (Sweden)

    Bogdane Ruta

    2016-12-01

    Full Text Available At the present stage of airline development the most effective way to increase safety is to introduce a systematic approach to the management of the organization. The creation of a single integrated management system including the combination of resources will make it possible to maintain the necessary level of quality of aviation services with safety as a key indicator. The article offers a model of such an integrated management system for medium level airlines.

  6. 19 CFR 122.134 - When airline does not have in-bond liquor storeroom.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false When airline does not have in-bond liquor storeroom. 122.134 Section 122.134 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Liquor Kits § 122.134 When airline does not have in-bond liquor storeroom. (a...

  7. 19 CFR 122.135 - When airline has in-bond liquor storeroom.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false When airline has in-bond liquor storeroom. 122.135 Section 122.135 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Liquor Kits § 122.135 When airline has in-bond liquor storeroom. (a) Restocking. Liquor...

  8. Enhancing Global Competitiveness: Benchmarking Airline Operational Performance in Highly Regulated Environments

    Science.gov (United States)

    Bowen, Brent D.; Headley, Dean E.; Kane, Karisa D.

    1998-01-01

    Enhancing competitiveness in the global airline industry is at the forefront of attention with airlines, government, and the flying public. The seemingly unchecked growth of major airline alliances is heralded as an enhancement to global competition. However, like many mega-conglomerates, mega-airlines will face complications driven by size regardless of the many recitations of enhanced efficiency. Outlined herein is a conceptual model to serve as a decision tool for policy-makers, managers, and consumers of airline services. This model is developed using public data for the United States (U.S.) major airline industry available from the U/S. Department of Transportation, Federal Aviation Administration, the National Aeronautics and Space Administration, the National Transportation Safety Board, and other public and private sector sources. Data points include number of accidents, pilot deviations, operational performance indicators, flight problems, and other factors. Data from these sources provide opportunity to develop a model based on a complex dot product equation of two vectors. A row vector is weighted for importance by a key informant panel of government, industry, and consumer experts, while a column vector is established with the factor value. The resulting equation, known as the national Airline Quality Rating (AQR), where Q is quality, C is weight, and V is the value of the variables, is stated Q=C[i1-19] x V[i1-19]. Looking at historical patterns of AQR results provides the basis for establishment of an industry benchmark for the purpose of enhancing airline operational performance. A 7 year average of overall operational performance provides the resulting benchmark indicator. Applications from this example can be applied to the many competitive environments of the global industry and assist policy-makers faced with rapidly changing regulatory challenges.

  9. Behaviors, movements, and transmission of droplet-mediated respiratory diseases during transcontinental airline flights

    Science.gov (United States)

    Weiss, Howard; Elon, Lisa; Si, Wenpei; Norris, Sharon L.

    2018-01-01

    With over 3 billion airline passengers annually, the inflight transmission of infectious diseases is an important global health concern. Over a dozen cases of inflight transmission of serious infections have been documented, and air travel can serve as a conduit for the rapid spread of newly emerging infections and pandemics. Despite sensational media stories and anecdotes, the risks of transmission of respiratory viruses in an airplane cabin are unknown. Movements of passengers and crew may facilitate disease transmission. On 10 transcontinental US flights, we chronicled behaviors and movements of individuals in the economy cabin on single-aisle aircraft. We simulated transmission during flight based on these data. Our results indicate there is low probability of direct transmission to passengers not seated in close proximity to an infectious passenger. This data-driven, dynamic network transmission model of droplet-mediated respiratory disease is unique. To measure the true pathogen burden, our team collected 229 environmental samples during the flights. Although eight flights were during Influenza season, all qPCR assays for 18 common respiratory viruses were negative. PMID:29555754

  10. Behaviors, movements, and transmission of droplet-mediated respiratory diseases during transcontinental airline flights.

    Science.gov (United States)

    Hertzberg, Vicki Stover; Weiss, Howard; Elon, Lisa; Si, Wenpei; Norris, Sharon L

    2018-04-03

    With over 3 billion airline passengers annually, the inflight transmission of infectious diseases is an important global health concern. Over a dozen cases of inflight transmission of serious infections have been documented, and air travel can serve as a conduit for the rapid spread of newly emerging infections and pandemics. Despite sensational media stories and anecdotes, the risks of transmission of respiratory viruses in an airplane cabin are unknown. Movements of passengers and crew may facilitate disease transmission. On 10 transcontinental US flights, we chronicled behaviors and movements of individuals in the economy cabin on single-aisle aircraft. We simulated transmission during flight based on these data. Our results indicate there is low probability of direct transmission to passengers not seated in close proximity to an infectious passenger. This data-driven, dynamic network transmission model of droplet-mediated respiratory disease is unique. To measure the true pathogen burden, our team collected 229 environmental samples during the flights. Although eight flights were during Influenza season, all qPCR assays for 18 common respiratory viruses were negative. Copyright © 2018 the Author(s). Published by PNAS.

  11. Adaptive resource allocation for efficient patient scheduling

    NARCIS (Netherlands)

    Vermeulen, Ivan B.; Bohte, Sander M.; Elkhuizen, Sylvia G.; Lameris, Han; Bakker, Piet J. M.; La Poutré, Han

    2009-01-01

    Efficient scheduling of patient appointments on expensive resources is a complex and dynamic task. A resource is typically used by several patient groups. To service these groups, resource capacity is often allocated per group, explicitly or implicitly. Importantly, due to fluctuations in demand,

  12. Optimal OFDMA Downlink Scheduling Under a Control Signaling Cost Constraint

    OpenAIRE

    Larsson, Erik G.

    2010-01-01

    This paper proposes a new algorithm for downlink scheduling in OFDMA systems. The method maximizes the throughput, taking into account the amount of signaling needed to transmit scheduling maps to the users. A combinatorial problem is formulated and solved via a dynamic programming approach reminiscent of the Viterbi algorithm. The total computational complexity of the algorithm is upper boundedby O(K^4N) where K is the number of users that are being considered for scheduling in a frame and N...

  13. Reflecting on the Germanwings Disaster: A Systematic Review of Depression and Suicide in Commercial Airline Pilots.

    Science.gov (United States)

    Pasha, Terouz; Stokes, Paul R A

    2018-01-01

    The 2015 Germanwings Flight 9525 disaster, in which 150 people were killed after the co-pilot may have intentionally crashed the plane in a suicide attempt, highlights the importance of better understanding the mental health of commercial airline pilots. However, there have been few systematic reviews investigating the topic of mental health in commercial aviation. This systematic review aims to identify the types and prevalence of mental health disorders that commercial airline pilots experience with a focus on mood disorders and suicide risk. A systematic literature search was performed using PubMed, EMBASE, and PsycINFO databases. Eligible studies were assessed and data was extracted and analyzed. 20 studies were identified. The prevalence of depression experienced by commercial airline pilots in this review ranged from 1.9% to 12.6%. Factors that negatively impacted the mental health of pilots included substance abuse, experiencing verbal or sexual abuse, disruption in sleep circadian rhythms and fatigue. This systematic review identifies that commercial airline pilots may experience depression at least as frequently as the general population. Commercial airline pilots experience occupational stressors, such as disrupted circadian rhythms and fatigue which may increase risks of developing mood disorders. Most studies identified in this review were cross-sectional in nature with substantial limitations. There is a clear need for further higher quality longitudinal studies to better understand the mental health of commercial airline pilots.

  14. Allergic reactions to peanuts, tree nuts, and seeds aboard commercial airliners.

    Science.gov (United States)

    Comstock, Sarah S; DeMera, Rich; Vega, Laura C; Boren, Eric J; Deane, Sean; Haapanen, Lori A D; Teuber, Suzanne S

    2008-07-01

    Minimal data exist on the prevalence and characteristics of in-flight reactions to foods. To characterize reactions to foods experienced by passengers aboard commercial airplanes and to examine information about flying with a food allergy available from airlines. Telephone questionnaires were administered to individuals in a peanut, tree nut, and seed allergy database who self-reported reactions aboard aircraft. Airlines were contacted to obtain information on food allergy policies. Forty-one of 471 individuals reported allergic reactions to food while on airplanes, including 4 reporting more than 1 reaction. Peanuts accounted for most of the reactions. Twenty-one individuals (51%) treated their reactions during flight. Only 12 individuals (29%) reported the reaction to a flight attendant. Six individuals went to an emergency department after landing, including 1 after a flight diversion. Airline personnel were notified of only 3 of these severe reactions. Comparison of information given to 3 different investigators by airline customer service representatives showed that inconsistencies regarding important information occurred, such as whether the airline regularly serves peanuts. In this group of mainly adults with severe nut/seed allergy, approximately 9% reported experiencing an allergic reaction to food while on board an airplane. Some reactions were serious and potentially life-threatening. Individuals commonly did not inform airline personnel about their experiences. In addition, the quality of information about flying with food allergies available from customer service departments is highly variable and, in some cases, incomplete or inaccurate.

  15. The impact of Southwest Airline's contribution to atmospheric Carbon Dioxide and Nitrous Oxide totals

    Science.gov (United States)

    Wilkerson, Cody L.

    Over the last century, aviation has grown to become an economical juggernaut. The industry creates innovation, connects people, and maintains a safety goal unlike any other field. However, as the world becomes more populated with technology and individuals, a general curiosity as to how human activity effects the planet is becoming of greater interest. This study presents what one domestic airline in the United States, Southwest Airlines, contributes to the atmospheric make-up of the planet. Utilizing various sources of quantifiable data, an outcome was reached that shows the amount of Carbon Dioxide and Nitrous Oxide produced by Southwest Airlines from 2002 to 2013. This topic was chosen due to the fact that there are no real quantifiable values of emission statistics from airlines available to the public. Further investigation allowed for Southwest Airlines to be compared to the overall Carbon Dioxide and Nitrous Oxide contributions of the United States for the year 2011. The results showed that with the absence of any set standard on emissions, it is vital that one should be established. The data showed that the current ICAO standard emission values showed a higher level of emissions than when Southwest Airline's fleet was analyzed using their actual fleet mix.

  16. Constraint-based job shop scheduling with ILOG SCHEDULER

    NARCIS (Netherlands)

    Nuijten, W.P.M.; Le Pape, C.

    1998-01-01

    We introduce constraint-based scheduling and discuss its main principles. An approximation algorithm based on tree search is developed for the job shop scheduling problem using ILOG SCHEDULER. A new way of calculating lower bounds on the makespan of the job shop scheduling problem is presented and

  17. Planning and scheduling - A schedule's performance

    International Nuclear Information System (INIS)

    Whitman, N.M.

    1993-01-01

    Planning and scheduling is a process whose time has come to PSI Energy. With an awareness of the challenges ahead, individuals must look for ways to enhance the corporate competitiveness. Working toward this goal means that each individual has to dedicate themselves to this more competitive corporate environment. Being competitive may be defined as the ability of each employee to add value to the corporation's economic well being. The timely and successful implementation of projects greatly enhances competitiveness. Those projects that do not do well often suffer from lack of proper execution - not for lack of talent or strategic vision. Projects are consumers of resources such as cash and people. They produce a return when completed and will generate a better return when properly completed utilizing proven project management techniques. Completing projects on time, within budget and meeting customer expectations is the way a corporation builds it's future. This paper offers suggestions on implementing planning and scheduling and provides a review of results in the form of management reports

  18. Data analysis with the DIANA meta-scheduling approach

    International Nuclear Information System (INIS)

    Anjum, A; McClatchey, R; Willers, I

    2008-01-01

    The concepts, design and evaluation of the Data Intensive and Network Aware (DIANA) meta-scheduling approach for solving the challenges of data analysis being faced by CERN experiments are discussed in this paper. Our results suggest that data analysis can be made robust by employing fault tolerant and decentralized meta-scheduling algorithms supported in our DIANA meta-scheduler. The DIANA meta-scheduler supports data intensive bulk scheduling, is network aware and follows a policy centric meta-scheduling. In this paper, we demonstrate that a decentralized and dynamic meta-scheduling approach is an effective strategy to cope with increasing numbers of users, jobs and datasets. We present 'quality of service' related statistics for physics analysis through the application of a policy centric fair-share scheduling model. The DIANA meta-schedulers create a peer-to-peer hierarchy of schedulers to accomplish resource management that changes with evolving loads and is dynamic and adapts to the volatile nature of the resources

  19. Constraint-based scheduling

    Science.gov (United States)

    Zweben, Monte

    1993-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  20. SPANR planning and scheduling

    Science.gov (United States)

    Freund, Richard F.; Braun, Tracy D.; Kussow, Matthew; Godfrey, Michael; Koyama, Terry

    2001-07-01

    SPANR (Schedule, Plan, Assess Networked Resources) is (i) a pre-run, off-line planning and (ii) a runtime, just-in-time scheduling mechanism. It is designed to support primarily commercial applications in that it optimizes throughput rather than individual jobs (unless they have highest priority). Thus it is a tool for a commercial production manager to maximize total work. First the SPANR Planner is presented showing the ability to do predictive 'what-if' planning. It can answer such questions as, (i) what is the overall effect of acquiring new hardware or (ii) what would be the effect of a different scheduler. The ability of the SPANR Planner to formulate in advance tree-trimming strategies is useful in several commercial applications, such as electronic design or pharmaceutical simulations. The SPANR Planner is demonstrated using a variety of benchmarks. The SPANR Runtime Scheduler (RS) is briefly presented. The SPANR RS can provide benefit for several commercial applications, such as airframe design and financial applications. Finally a design is shown whereby SPANR can provide scheduling advice to most resource management systems.

  1. Improving the performance of sorter systems by scheduling inbound containers

    NARCIS (Netherlands)

    Haneyah, S.W.A.; Schutten, Johannes M.J.; Fikse, K.

    2013-01-01

    This paper addresses the inbound containers scheduling problem for automated sorter systems in two different industrial sectors: parcel & postal sorting and baggage handling. We build on existing literature, particularly on the dynamic load balancing algorithm designed for the parcel hub scheduling

  2. Multi-agent Pareto appointment exchanging in hospital patient scheduling

    NARCIS (Netherlands)

    I.B. Vermeulen (Ivan); S.M. Bohte (Sander); D.J.A. Somefun (Koye); J.A. La Poutré (Han)

    2007-01-01

    htmlabstractWe present a dynamic and distributed approach to the hospital patient scheduling problem, in which patients can have multiple appointments that have to be scheduled to different resources. To efficiently solve this problem we develop a multi-agent Pareto-improvement appointment

  3. Multi-agent Pareto appointment exchanging in hospital patient scheduling

    NARCIS (Netherlands)

    Vermeulen, I.B.; Bohté, S.M.; Somefun, D.J.A.; Poutré, La J.A.

    2007-01-01

    We present a dynamic and distributed approach to the hospital patient scheduling problem, in which patients can have multiple appointments that have to be scheduled to different resources. To efficiently solve this problem we develop a multi-agent Pareto-improvement appointment exchanging algorithm:

  4. Throughput maximization of parcel sorter systems by scheduling inbound containers

    NARCIS (Netherlands)

    Haneyah, S.W.A.; Schutten, Johannes M.J.; Fikse, K.; Clausen, Uwe; ten Hompel, Michael; Meier, J. Fabian

    2013-01-01

    This paper addresses the inbound container scheduling problem for automated sorter systems in express parcel sorting. The purpose is to analyze which container scheduling approaches maximize the throughput of sorter systems. We build on existing literature, particularly on the dynamic load balancing

  5. Agent-based transportation planning compared with scheduling heuristics

    NARCIS (Netherlands)

    Mes, Martijn R.K.; van der Heijden, Matthijs C.; van Harten, Aart

    2004-01-01

    Here we consider the problem of dynamically assigning vehicles to transportation orders that have di¤erent time windows and should be handled in real time. We introduce a new agent-based system for the planning and scheduling of these transportation networks. Intelligent vehicle agents schedule

  6. Cosmic radiation dosimetry in international flights argentine airlines

    International Nuclear Information System (INIS)

    Ciancio, Vicente R.; Oliveri, Pedro V.; Di Giovan B, Gustavo; Ciancio, Vanina L.; Lewis, Brent J.; Green, Anna R.; Bennet, L.

    2008-01-01

    Full text: Introduction: In commercial aviation the most important determinants of radiation exposure in humans are the altitude, latitude, flight duration and the solar cycle's period. This study was conducted to address this type of exposure trough radiation dosimetry. Method: The study was performed in the business-class cabin of an Airbus 340-200 aircraft, provided by Argentine Airlines, during 2 flights routes: New York-Miami-Buenos Aires (trans equatorial) and Buenos Aires-Auckland (circumpolar). Measurements addressed the electromagnetic spectrum or low Linear Energy Transfer (LET) and corpuscular radiation (High LET). The instruments used were an Ion Chamber (IC), to measure the ionizing component of radiation (i.e., gamma radiation), the SWENDI, to measure only the neutron component, and the Tissue Equivalent Proportional Counter (TEPC) for measuring all radiation types. Results: The routes' dose rates are presented in the table. TEPC rates agreed with the LET findings. The total dose rates of high latitude flights were higher than those of low latitude flights. The SWENDI (High LET) results for the flights over the equator, at low latitude, represented only 1/3 of the total radiation. The New York-Miami and Buenos Aires-Auckland flights, at high latitude, represented just under 1/2 of the Total radiation (-45%). Conclusion: Based on the results of this study, the annual dose rates of radiation exposure of air crew personnel serving on international flights offered by Argentine Airlines is between 3 and 7 mSv. This rate is higher than the maximum recommended for the general population by the International Commission on Radiological Protection (ICRP), which is 1 milli Sv./y. Therefore, these personnel must be officially considered 'Occupationally Exposed to Radiation' in way to provide the appropriate measures that must be implemented for their protection in accordance to ICRP guidelines. Dose(uSv): Route N Y-Miami, IC 6.07, SWENDI 5.07, TEPC 11.04; Route

  7. Outcomes of medical emergencies on commercial airline flights.

    Science.gov (United States)

    Peterson, Drew C; Martin-Gill, Christian; Guyette, Francis X; Tobias, Adam Z; McCarthy, Catherine E; Harrington, Scott T; Delbridge, Theodore R; Yealy, Donald M

    2013-05-30

    Worldwide, 2.75 billion passengers fly on commercial airlines annually. When in-flight medical emergencies occur, access to care is limited. We describe in-flight medical emergencies and the outcomes of these events. We reviewed records of in-flight medical emergency calls from five domestic and international airlines to a physician-directed medical communications center from January 1, 2008, through October 31, 2010. We characterized the most common medical problems and the type of on-board assistance rendered. We determined the incidence of and factors associated with unscheduled aircraft diversion, transport to a hospital, and hospital admission, and we determined the incidence of death. There were 11,920 in-flight medical emergencies resulting in calls to the center (1 medical emergency per 604 flights). The most common problems were syncope or presyncope (37.4% of cases), respiratory symptoms (12.1%), and nausea or vomiting (9.5%). Physician passengers provided medical assistance in 48.1% of in-flight medical emergencies, and aircraft diversion occurred in 7.3%. Of 10,914 patients for whom postflight follow-up data were available, 25.8% were transported to a hospital by emergency-medical-service personnel, 8.6% were admitted, and 0.3% died. The most common triggers for admission were possible stroke (odds ratio, 3.36; 95% confidence interval [CI], 1.88 to 6.03), respiratory symptoms (odds ratio, 2.13; 95% CI, 1.48 to 3.06), and cardiac symptoms (odds ratio, 1.95; 95% CI, 1.37 to 2.77). Most in-flight medical emergencies were related to syncope, respiratory symptoms, or gastrointestinal symptoms, and a physician was frequently the responding medical volunteer. Few in-flight medical emergencies resulted in diversion of aircraft or death; one fourth of passengers who had an in-flight medical emergency underwent additional evaluation in a hospital. (Funded by the National Institutes of Health.).

  8. Perceptions of Service Quality: An Empirical Assessment of Modified SERVQUAL Model among Domestic Airline Carriers in Nigeria

    OpenAIRE

    Ganiyu Rahim A.

    2016-01-01

    Literature is replete with a large number of theories related to service quality measurement and dimensions in an airline context. To date, there is no consensus of opinion on the generic model and of the number of dimensions most appropriate to evaluate service quality in airline industry. This study investigates service quality dimensions in the Nigerian airline industry. The cross-sectional survey research design was adopted. Convenience sampling was used to select 800 respondents among de...

  9. The career cost: does it pay for a military pilot to leave the service for the airlines?

    OpenAIRE

    Hodges, Jeffrey A.

    2015-01-01

    Approved for public release; distribution is unlimited The military is experiencing a pilot retention problem that is getting worse. The government spends millions of dollars training pilots in the most advanced aircraft in the world, only to watch them leave for the commercial airline industry at the first opportunity. As airline pilot hiring continues to improve, military pilots will depart the services for the assumed increase in financial compensation of the airlines. This thesis compa...

  10. Airline Safety Management: The development of a proactive safety mechanism model for the evolution of safety management system

    OpenAIRE

    Hsu, Yueh-Ling

    2004-01-01

    The systemic origins of many accidents have led to heightened interest in the way in which organisations identify and manage risks within the airline industry. The activities which are thought to represent the term "organisational accident", "safety culture" and "proactive approach" are documented and seek to explain the fact that airlines differ in their willingness and ability to conduct safety management. However, an important but yet relatively undefined task in the airline...

  11. Estimating exponential scheduling preferences

    DEFF Research Database (Denmark)

    Hjorth, Katrine; Börjesson, Maria; Engelson, Leonid

    2015-01-01

    of car drivers' route and mode choice under uncertain travel times. Our analysis exposes some important methodological issues related to complex non-linear scheduling models: One issue is identifying the point in time where the marginal utility of being at the destination becomes larger than the marginal......Different assumptions about travelers' scheduling preferences yield different measures of the cost of travel time variability. Only few forms of scheduling preferences provide non-trivial measures which are additive over links in transport networks where link travel times are arbitrarily...... utility of being at the origin. Another issue is that models with the exponential marginal utility formulation suffer from empirical identification problems. Though our results are not decisive, they partly support the constant-affine specification, in which the value of travel time variability...

  12. Post LS1 schedule

    CERN Document Server

    Lamont, M

    2014-01-01

    The scheduling limits for a typical long year taking into account technical stops, machine development, spe- cial physics runs are presented. An attempt is then made to outline a ten year post LS1 schedule taking into account the disparate requirements outlined in the previous talks in this session. The demands on the planned long shutdowns and the impact of these demands on their proposed length will be discussed. The option of using ion running as a pre-shutdown cool-down period will be addressed.

  13. Autonomous scheduling technology for Earth orbital missions

    Science.gov (United States)

    Srivastava, S.

    1982-01-01

    The development of a dynamic autonomous system (DYASS) of resources for the mission support of near-Earth NASA spacecraft is discussed and the current NASA space data system is described from a functional perspective. The future (late 80's and early 90's) NASA space data system is discussed. The DYASS concept, the autonomous process control, and the NASA space data system are introduced. Scheduling and related disciplines are surveyed. DYASS as a scheduling problem is also discussed. Artificial intelligence and knowledge representation is considered as well as the NUDGE system and the I-Space system.

  14. Optimal scheduling of coproduction with a storage

    International Nuclear Information System (INIS)

    Ravn, H.F.; Rygard, J.M.

    1993-02-01

    We consider the problem of optimal scheduling of a system with combined heat and heat (CHP) units and a heat storege. The purpose of the heat storage is to permit a partial decoupling of the variations in the demand for heat and electrical power. We formulate the problem of optimal scheduling as that of minimizing the total costs over the planning period. The heat demand from the district heating system and the ''shadow prices'' for the electrical power system are taken as externally given parameters. The resulting model is solved by dynamic programming. We describe implementation details and we give examples of result of the optimization. (au) (12 refs.)

  15. Automated Scheduling Via Artificial Intelligence

    Science.gov (United States)

    Biefeld, Eric W.; Cooper, Lynne P.

    1991-01-01

    Artificial-intelligence software that automates scheduling developed in Operations Mission Planner (OMP) research project. Software used in both generation of new schedules and modification of existing schedules in view of changes in tasks and/or available resources. Approach based on iterative refinement. Although project focused upon scheduling of operations of scientific instruments and other equipment aboard spacecraft, also applicable to such terrestrial problems as scheduling production in factory.

  16. Passenger Perception towards E-ticketing Services, Airline Industry

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Nail Reshidi

    2014-02-01

    Full Text Available This paper aims to identify the critical dominant incidents and key instigators that influence on usage or lack of usage of e-ticketing by Kosovo Air Passengers. The research at hand utilizes the Grounded Theory of Barney Glaser and Anselm Strauss, and the Critical Incident Technique in order to identify the factors that influence on the (diss satisfaction of the travellers in using e-ticketing. For the purpose of this paper, the empirical data were gathered through interviews by using open ended questions. Among 93 interviews with the random selected passengers, 13 interviews were deemed as invalid. The empirical results highlighted the need for raising the consciousness regarding the efficacy and the advantages of eticketing. On the other hand, many other passengers cannot conceive the possibility of travelling without use of e-ticketing, given that in the past they spent much time in finding the right agent, desired destination, purchase difficulties in making reservation, confirmation, changes, or they had to carry large amounts of cash money to buy tickets which raised insecurity concerns. Research is limited only to the description of critical incidents that occurred in Prishtina International Airport. Majority of the respondents were highly-educated with high income status. These characteristics create a bias and constrain our ability to extrapolate from the findings. Nevertheless, the study serves as a point for more in-depth analysis and discussion on e-ticketing behaviour in Airline industry.

  17. Management of strategic coopetition among partners within international airline alliances

    Directory of Open Access Journals (Sweden)

    Frank Himpel

    2012-03-01

    Full Text Available Background: International network-carriers span the globe by linking airports on all five continents. At the core of those networks are hub-airports that serve as the centers for (inter-national in- and outbound traffic flows. From a business model point of view, the major international carriers are so-called network-carriers, for their core concept is based on transfer-oriented hub-and-spoke-systems. In order to maximize revenue streams of network-carriers, changes in strategic slot allocation and strategic net planning are becoming increasingly relevant. The aim of this work was to analyze the impact of various elements of the management of strategic coopetition among partners within international airline alliances on the revenues obtained by individual partners. Methods: the problems related to the optimization of strategic slot allocation and strategic net planning from the point of view of the individual profit shared and added net contribution margins were discussed. Results and conclusions: Two extreme scenarios may be projected. The first one is that partners within a given alliance system may start to increase merger and acquisition activities. Thereby scale effects may be utilized. The other one is, when rivalry becomes too dominant over time, some partners may (have to exit alliance systems. Thereby "atomic" subsystems may be on the rebound. Strategic coopetition management is aimed to keep leading international network carriers "on track" in the field of alliance management of that nature.

  18. Duty hours and incidents in flight among commercial airline pilots.

    Science.gov (United States)

    O'Hagan, Anna Donnla; Issartel, Johann; Fletcher, Richard; Warrington, Giles

    2016-01-01

    Working long duty hours has often been associated with increased risk of incidents and accidents in transport industries. Despite this, information regarding the intermediate relationship between duty hours and incident risk is limited. This study aimed to test a work hours/incident model to identify the interplay of factors contributing to incidents within the aviation industry. Nine hundred and fifty-four European-registered commercial airline pilots completed a 30-item survey investigating self-report attitudes and experiences of fatigue. Path analysis was used to test the proposed model. The fit indices indicated this to be a good fit model (χ(2) = 11.066, df = 5, p = 0.05; Comparative Fit Index = 0.991; Normed Fit Index = 0.984; Tucker-Lewis Index = 0.962; Root Mean Square of Approximation = 0.036). Highly significant relationships were identified between duty hours and sleep disturbance (r = 0.18, p hours through to self-reported incidents in flight was identified. Further investigation employing both objective and subjective measures of sleep and fatigue is needed.

  19. Epidemiological and biomechanical evaluation of airline baggage handling.

    Science.gov (United States)

    Tafazzol, Alireza; Aref, Samin; Mardani, Majid; Haddad, Omid; Parnianpour, Mohamad

    2016-01-01

    Musculoskeletal disorders (MSDs) are prevalent among airline baggage handlers due to manual materials handling. In this study, the Nordic musculoskeletal questionnaire (NMQ), the revised National Institute for Occupational Safety and Health (NIOSH) lifting equation, and the University of Michigan 3D Static Strength Prediction Program™ (3DSSPP) were used to analyze MSDs among baggage handlers. The NMQ was filled out by 209 baggage handlers and 46 arbitrarily selected baggage handlers were evaluated using the NIOSH method and 3DSSPP. The obtained results showed that the most common MSDs occurred in the lower back region. The next risky regions included knees, neck, and upper back, respectively. The NIOSH results confirmed that the subjects lifted loads heavier than the permitted limit and their lifting postures were inappropriate. The results of the 3DSSPP also indicated that compression forces exceeded the NIOSH limit in these awkward postures. Relying on this study, holding compulsory ergonomic lifting training courses could be proposed for workers and regulations adjusting an upper limit for maximum baggage weight must be also enacted in order to improve occupational health and prevent the prevalence of increasing MSDs.

  20. Revealing the structure of the world airline network

    Science.gov (United States)

    Verma, T.; Araújo, N. A. M.; Herrmann, H. J.

    2014-07-01

    Resilience of most critical infrastructures against failure of elements that appear insignificant is usually taken for granted. The World Airline Network (WAN) is an infrastructure that reduces the geographical gap between societies, both small and large, and brings forth economic gains. With the extensive use of a publicly maintained data set that contains information about airports and alternative connections between these airports, we empirically reveal that the WAN is a redundant and resilient network for long distance air travel, but otherwise breaks down completely due to removal of short and apparently insignificant connections. These short range connections with moderate number of passengers and alternate flights are the connections that keep remote parts of the world accessible. It is surprising, insofar as there exists a highly resilient and strongly connected core consisting of a small fraction of airports (around 2.3%) together with an extremely fragile star-like periphery. Yet, in spite of their relevance, more than 90% of the world airports are still interconnected upon removal of this core. With standard and unconventional removal measures we compare both empirical and topological perceptions for the fragmentation of the world. We identify how the WAN is organized into different classes of clusters based on the physical proximity of airports and analyze the consequence of this fragmentation.

  1. Costs and Benefits of Stopping the Clock. How Airlines Profit from Changes in the EU ETS

    Energy Technology Data Exchange (ETDEWEB)

    Nelissen, D.; Faber, J.

    2012-12-15

    All flights arriving at or departing from EU airports have been included in the EU ETS from the beginning of 2012. Airlines have to surrender allowances for emissions on flights to and from EU airports. A share of the allowances has been issued to the airlines for free, the remainder needs to be acquired at an auction or from the market. In November 2012, the European Commission proposed to exempt intercontinental flights from the EU ETS for 2012, an initiative branded as 'Stopping the Clock'. As a result of this change, airlines on intercontinental routes are likely to experience additional windfall profit, since they have probably anticipated ETS-related expenditures on these routes, which they will now not incur. In addition, all airlines have a windfall profit since they are likely to pass on the value of the free allowances, as has been demonstrated to happen in all other sectors that have received free allowances. This note estimates the windfall profits. The report distinguishes two types of windfall profits: (1) Profits that occur because the opportunity costs of free allowances received for intercontinental flights have been passed on. These windfall profits would also have occurred without the 'stop the clock' exemption. We call them ETS Windfall. (2) Profits that occur because airlines have raised their revenues on intercontinental flights, but will not need to buy allowances either at the auction or from other actors because of the exemption. We call them Stopping the Clock Windfall. Depending on the cost pass through, the total windfall profits range from euro 679 million to euro 1,358 million. About a third of these windfall profits arise from the exemption of intercontinental flights. EU airlines are expected to reap the largest share of the windfall due to the change in regulation (55%), followed by US airlines (13%).

  2. Airline Safety Improvement Through Experience with Near-Misses: A Cautionary Tale.

    Science.gov (United States)

    Madsen, Peter; Dillon, Robin L; Tinsley, Catherine H

    2016-05-01

    In recent years, the U.S. commercial airline industry has achieved unprecedented levels of safety, with the statistical risk associated with U.S. commercial aviation falling to 0.003 fatalities per 100 million passengers. But decades of research on organizational learning show that success often breeds complacency and failure inspires improvement. With accidents as rare events, can the airline industry continue safety advancements? This question is complicated by the complex system in which the industry operates where chance combinations of multiple factors contribute to what are largely probabilistic (rather than deterministic) outcomes. Thus, some apparent successes are realized because of good fortune rather than good processes, and this research intends to bring attention to these events, the near-misses. The processes that create these near-misses could pose a threat if multiple contributing factors combine in adverse ways without the intervention of good fortune. Yet, near-misses (if recognized as such) can, theoretically, offer a mechanism for continuing safety improvements, above and beyond learning gleaned from observable failure. We test whether or not this learning is apparent in the airline industry. Using data from 1990 to 2007, fixed effects Poisson regressions show that airlines learn from accidents (their own and others), and from one category of near-misses-those where the possible dangers are salient. Unfortunately, airlines do not improve following near-miss incidents when the focal event has no clear warnings of significant danger. Therefore, while airlines need to and can learn from certain near-misses, we conclude with recommendations for improving airline learning from all near-misses. © 2015 Society for Risk Analysis.

  3. Economic Benefit from Progressive Integration of Scheduling and Control for Continuous Chemical Processes

    Directory of Open Access Journals (Sweden)

    Logan D. R. Beal

    2017-12-01

    Full Text Available Performance of integrated production scheduling and advanced process control with disturbances is summarized and reviewed with four progressive stages of scheduling and control integration and responsiveness to disturbances: open-loop segregated scheduling and control, closed-loop segregated scheduling and control, open-loop scheduling with consideration of process dynamics, and closed-loop integrated scheduling and control responsive to process disturbances and market fluctuations. Progressive economic benefit from dynamic rescheduling and integrating scheduling and control is shown on a continuously stirred tank reactor (CSTR benchmark application in closed-loop simulations over 24 h. A fixed horizon integrated scheduling and control formulation for multi-product, continuous chemical processes is utilized, in which nonlinear model predictive control (NMPC and continuous-time scheduling are combined.

  4. Harmonious personnel scheduling

    NARCIS (Netherlands)

    Fijn van Draat, Laurens; Post, Gerhard F.; Veltman, Bart; Winkelhuijzen, Wessel

    2006-01-01

    The area of personnel scheduling is very broad. Here we focus on the ‘shift assignment problem’. Our aim is to discuss how ORTEC HARMONY handles this planning problem. In particular we go into the structure of the optimization engine in ORTEC HARMONY, which uses techniques from genetic algorithms,

  5. Hybrid job shop scheduling

    NARCIS (Netherlands)

    Schutten, Johannes M.J.

    1995-01-01

    We consider the problem of scheduling jobs in a hybrid job shop. We use the term 'hybrid' to indicate that we consider a lot of extensions of the classic job shop, such as transportation times, multiple resources, and setup times. The Shifting Bottleneck procedure can be generalized to deal with

  6. Practical job shop scheduling

    NARCIS (Netherlands)

    Schutten, Johannes M.J.

    1998-01-01

    The Shifting Bottleneck procedure is an intuitive and reasonably good approximation algorithm for the notoriously difficult classical job shop scheduling problem. The principle of decomposing a classical job shop problem into a series of single-machine problems can also easily be applied to job shop

  7. "Creative" Work Schedules.

    Science.gov (United States)

    Blai, Boris

    Many creative or flexible work scheduling options are becoming available to the many working parents, students, handicapped persons, elderly individuals, and others who are either unable or unwilling to work a customary 40-hour work week. These options may be broadly categorized as either restructured or reduced work time options. The three main…

  8. An Experimental Evaluation of Real-Time DVFS Scheduling Algorithms

    OpenAIRE

    Saha, Sonal

    2011-01-01

    Dynamic voltage and frequency scaling (DVFS) is an extensively studied energy manage- ment technique, which aims to reduce the energy consumption of computing platforms by dynamically scaling the CPU frequency. Real-Time DVFS (RT-DVFS) is a branch of DVFS, which reduces CPU energy consumption through DVFS, while at the same time ensures that task time constraints are satisfied by constructing appropriate real-time task schedules. The literature presents numerous RT-DVFS schedul...

  9. An introduction to optimal satellite range scheduling

    CERN Document Server

    Vázquez Álvarez, Antonio José

    2015-01-01

    The satellite range scheduling (SRS) problem, an important operations research problem in the aerospace industry consisting of allocating tasks among satellites and Earth-bound objects, is examined in this book. SRS principles and solutions are applicable to many areas, including: Satellite communications, where tasks are communication intervals between sets of satellites and ground stations Earth observation, where tasks are observations of spots on the Earth by satellites Sensor scheduling, where tasks are observations of satellites by sensors on the Earth. This self-contained monograph begins with a structured compendium of the problem and moves on to explain the optimal approach to the solution, which includes aspects from graph theory, set theory, game theory and belief networks. This book is accessible to students, professionals and researchers in a variety of fields, including: operations research, optimization, scheduling theory, dynamic programming and game theory. Taking account of the distributed, ...

  10. The ASDEX Upgrade discharge schedule

    International Nuclear Information System (INIS)

    Neu, G.; Engelhardt, K.; Raupp, G.; Treutterer, W.; Zasche, D.; Zehetbauer, T.

    2007-01-01

    ASDEX Upgrade's recently commissioned discharge control system (DCS) marks the transition from a traditional programmed system to a highly flexible 'data driven' one. The allocation of application processes (APs) to controllers, the interconnection of APs through uniquely named signals, and AP control parameter values are all defined as data, and can easily be adapted to the requirements of a particular discharge. The data is laid down in a set of XML documents which APs request via HTTP from a configuration server before a discharge. The use of XML allows for easy parsing, and structural validation through (XSD) schemas. The central input to the configuration process is the discharge schedule (DS), which embodies the dynamic behaviour of a planned discharge as reference trajectories grouped in segments, concatenated through transition conditions. Editing, generation and validation tools, and version control through CVS allow for efficient management of DSs

  11. Designing a fuzzy scheduler for hard real-time systems

    Science.gov (United States)

    Yen, John; Lee, Jonathan; Pfluger, Nathan; Natarajan, Swami

    1992-01-01

    In hard real-time systems, tasks have to be performed not only correctly, but also in a timely fashion. If timing constraints are not met, there might be severe consequences. Task scheduling is the most important problem in designing a hard real-time system, because the scheduling algorithm ensures that tasks meet their deadlines. However, the inherent nature of uncertainty in dynamic hard real-time systems increases the problems inherent in scheduling. In an effort to alleviate these problems, we have developed a fuzzy scheduler to facilitate searching for a feasible schedule. A set of fuzzy rules are proposed to guide the search. The situation we are trying to address is the performance of the system when no feasible solution can be found, and therefore, certain tasks will not be executed. We wish to limit the number of important tasks that are not scheduled.

  12. Fatiguing effect of multiple take-offs and landings in regional airline operations.

    Science.gov (United States)

    Honn, Kimberly A; Satterfield, Brieann C; McCauley, Peter; Caldwell, J Lynn; Van Dongen, Hans P A

    2016-01-01

    Fatigue is a risk factor for flight performance and safety in commercial aviation. In US commercial aviation, to help to curb fatigue, the maximum duration of flight duty periods is regulated based on the scheduled start time and the number of flight segments to be flown. There is scientific support for regulating maximum duty duration based on scheduled start time; fatigue is well established to be modulated by circadian rhythms. However, it has not been established scientifically whether the number of flight segments, per se, affects fatigue. To address this science gap, we conducted a randomized, counterbalanced, cross-over study with 24 active-duty regional airline pilots. Objective and subjective fatigue was compared between a 9-hour duty day with multiple take-offs and landings versus a duty day of equal duration with a single take-off and landing. To standardize experimental conditions and isolate the fatiguing effect of the number of segments flown, the entire duty schedules were carried out in a high-fidelity, moving-base, full-flight, regional jet flight simulator. Steps were taken to maintain operational realism, including simulated airplane inspections and acceptance checks, use of realistic dispatch releases and airport charts, real-world air traffic control interactions, etc. During each of the two duty days, 10 fatigue test bouts were administered, which included a 10-minute Psychomotor Vigilance Test (PVT) assessment of objective fatigue and Samn-Perelli (SP) and Karolinska Sleepiness Scale (KSS) assessments of subjective sleepiness/fatigue. Results showed a greater build-up of objective and subjective fatigue in the multi-segment duty day than in the single-segment duty day. With duty start time and duration and other variables that could impact fatigue levels held constant, the greater build-up of fatigue in the multi-segment duty day was attributable specifically to the difference in the number of flight segments flown. Compared to findings in

  13. Airline Service Quality Performance 234 (On-Time performance data).

    Science.gov (United States)

    2011-04-01

    This CD presents data reported by U.S. certificated air carriers so that information on the air carriers' quality of service can be made available to consumers of air transportation. Carriers within 1% or more of the total domestic scheduled service ...

  14. Airline Service Quality Performance 234 (On-Time performance data).

    Science.gov (United States)

    2011-07-01

    This CD presents data reported by U.S. certificated air carriers so that information on the air carriers' quality of service can be made available to consumers of air transportation. Carriers within 1% or more of the total domestic scheduled service ...

  15. American Consumer’s Attitudes towards Different Airline Companies Channels: A Comparison of transaction Methods

    Directory of Open Access Journals (Sweden)

    Talha Harcar

    2012-03-01

    Full Text Available Consumers are increasingly challenging better performance from companies, and these demands are being met through improvements in technology and flexibility of services. As a result of recent progresses and developments in electronic marketing, the physical locations of brick and mortar businesses have become less significant since transactions can now be accomplished in cyberspace. In this paper, consumer attitudes towards online transactions for the airline industry are examined. Despite the growing acceptance of alternative delivery channels, the travel agencies remain an essential part of the customer-airline company. It can be argued that the travel agencies not only represent an opportunity for implementing costumer relationship, but they also remain an important point of contact for sales, service, and consultative interactions. Data has been analyzed using factor analysis technique. The study presents a broad picture of the level of preference of airline customers among the available distribution channels and sheds light on how airline companies should allocate resources among the different channels. The empirical study findings indicate that online transactions for the airline industry will gain in importance and its use will accelerate at a faster rate in the coming years.

  16. The Role of Consumer Experiences in Building the image of brands: A Study in Airlines

    Directory of Open Access Journals (Sweden)

    Ana Iris Tomás Vasconcelos

    2015-04-01

    Full Text Available Studies on brand and consumer experience gained emphasis from the twentieth century, however the relationship between these themes still has gaps. Therefore, this study examines the role of consumer experiences in building the brand image through the identification of thoughts, feelings and actions arising from consumer experiences with airlines, and the types of associations that the consumer makes such marks. Therefore, a variation of qualitative critical incident technique was used, considering those remembered experiences that have excelled in consumer perception, interviewing ten users of air services, based on a two parts semi-structured form: description of experiences with airlines and information about the image of the brands of airlines. The analyzed data have revealed that thoughts, feelings and actions arising from consumer experiences become important elements in shaping the perception of brands of airlines. Through the consumption experience, consumers mainly use the service attributes to build their perception of the marks of the airlines. These attributes are used either directly as to support other types of associations such as those related to company size.

  17. An international foodborne outbreak of shigellosis associated with a commercial airline.

    Science.gov (United States)

    Hedberg, C W; Levine, W C; White, K E; Carlson, R H; Winsor, D K; Cameron, D N; MacDonald, K L; Osterholm, M T

    1992-12-09

    To determine the source of an international outbreak of shigellosis associated with consumption of food served by a Minnesota-based airline. Cohort studies of players and staff of a Minnesota-based professional football team and passengers on flights with a confirmed case of outbreak-associated Shigella sonnei infection. Community- and industry-based studies conducted from October through November 1988. Sixty-five football team players and staff, and 725 airline passengers in the cohort studies. Twenty-one (32%) of 65 football players and staff developed shigellosis that was associated with consumption of cold sandwiches prepared at the airline flight kitchen (relative risk [RR], 17.1; 95% confidence interval [Cl], 2.4 to 120; P airline passengers, and flight attendants. Thirty (4.1%) of 725 passengers on 13 flights with confirmed cases had confirmed or probable shigellosis. Illness was associated with consumption of cold food items served on the flights and prepared by hand at the airline flight kitchen (RR, 5.7; 95% Cl, 1.4 to 23.5; P food items or elimination of these items from menus.

  18. Realistic Scheduling Mechanism for Smart Homes

    Directory of Open Access Journals (Sweden)

    Danish Mahmood

    2016-03-01

    Full Text Available In this work, we propose a Realistic Scheduling Mechanism (RSM to reduce user frustration and enhance appliance utility by classifying appliances with respective constraints and their time of use effectively. Algorithms are proposed regarding functioning of home appliances. A 24 hour time slot is divided into four logical sub-time slots, each composed of 360 min or 6 h. In these sub-time slots, only desired appliances (with respect to appliance classification are scheduled to raise appliance utility, restricting power consumption by a dynamically modelled power usage limiter that does not only take the electricity consumer into account but also the electricity supplier. Once appliance, time and power usage limiter modelling is done, we use a nature-inspired heuristic algorithm, Binary Particle Swarm Optimization (BPSO, optimally to form schedules with given constraints representing each sub-time slot. These schedules tend to achieve an equilibrium amongst appliance utility and cost effectiveness. For validation of the proposed RSM, we provide a comparative analysis amongst unscheduled electrical load usage, scheduled directly by BPSO and RSM, reflecting user comfort, which is based upon cost effectiveness and appliance utility.

  19. Sport Marketing and Sponsorship: Case of Turkish Airlines Corporation

    Directory of Open Access Journals (Sweden)

    Ahmet SARITAS

    2017-05-01

    Full Text Available In previous decades, sport activities were hold only in local and regional areas and they used to attract only a small group of people. These activities were mostly far from professionalism and mainly amateurish. Reaching many people took too much time. After the developments in technology and especially in mass communication systems, all sportive branches have started to reach much more people. Today, sport activities are followed by many people. The sport activities today are not only a sport but also a sector which run millions of dollars. Because of these developments, a concept called as “sport industry” has emerged. Especially football and other specific branches of sports such as basketball, volleyball and baseball have started to reach much more people. Male and female athletes in this industry have become well-known stars. Big companies have signed sponsorship agreements with world-famous stars and teams, and by this way they have started to market their products to the target consumers. Many of old and big companies have realized the positive effect of sport on the people. So, they have tried to introduce themselves in global market through some of sport clubs or organizations. Many old companies in the world have been applying this strategy for marketing. This strategy is getting more popular day by day. By developing technology and globalization, big Turkish companies have tended to provide sport sponsorships. As a typical example, Turkish Airlines Corporation has been trying to increase its brand familiarity and reliability through advertisement for 10 years. In this study in which the sponsorship activities of THY are examined, the explorational research type that is mostly used with case research, has been carried out by deepening the information collected from secondary data. Marketing and sponsorship activities which were used by THY have been analyzed, and material and immaterial values gained by THY by means of these

  20. Effects of malicious ocular laser exposure in commercial airline pilots.

    Science.gov (United States)

    Palakkamanil, Mathew M; Fielden, Michael P

    2015-12-01

    Intentional malicious laser strikes on commercial pilots are committed by individuals who target a laser into airplane cockpits during takeoff and landing. Because laser exposure to pilots is a relatively new but growing occurrence, our study investigates the ocular effect of this laser exposure in pilots. Retrospective chart review by a single ophthalmologist. All commercial airline pilots (58 male, 3 female) who experienced a laser strike while flying between April 2012 and November 2014 who presented to our clinic were included. A retrospective chart review was performed in a retinal specialist's practice. Ocular assessment was performed within 3 days of laser exposure. A complete ophthalmic evaluation was conducted, including Early Treatment Diabetic Retinopathy Study visual acuity, colour vision, visual fields, intraocular pressure, slit-lamp examination, dilated fundus examination, colour fundus photographs, and ocular coherence tomography. Sixty-four laser strike incidents involving commercial pilots were included. All pilots in the study experienced some degree of immediate ocular irritation or light sensitivity. No definite cases of ocular damage were attributed to laser strikes. No pilot had any functional ocular deficits. Our study revealed that laser strikes on aircraft did not result in permanent visual functional or structural deficits. However, laser strikes cause immediate visual effects, including glare, flash blindness, and ocular irritation that can interfere with a pilot's visual function. Given the widespread accessibility of high-power lasers and the rapid increase in incidents, laser strikes threaten to jeopardize aviation safety unless effective preventative measures are put in place. Copyright © 2015 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  1. Scheduling techniques in the Request Oriented Scheduling Engine (ROSE)

    Science.gov (United States)

    Zoch, David R.

    1991-01-01

    Scheduling techniques in the ROSE are presented in the form of the viewgraphs. The following subject areas are covered: agenda; ROSE summary and history; NCC-ROSE task goals; accomplishments; ROSE timeline manager; scheduling concerns; current and ROSE approaches; initial scheduling; BFSSE overview and example; and summary.

  2. Location-based Scheduling

    DEFF Research Database (Denmark)

    Andersson, Niclas; Christensen, Knud

    on the market. However, CPM is primarily an activity based method that takes the activity as the unit of focus and there is criticism raised, specifically in the case of construction projects, on the method for deficient management of construction work and continuous flow of resources. To seek solutions...... to the identified limitations of the CPM method, an alternative planning and scheduling methodology that includes locations is tested. Location-based Scheduling (LBS) implies a shift in focus, from primarily the activities to the flow of work through the various locations of the project, i.e. the building. LBS uses...... the graphical presentation technique of Line-of-balance, which is adapted for planning and management of work-flows that facilitates resources to perform their work without interruptions caused by other resources working with other activities in the same location. As such, LBS and Lean Construction share...

  3. 75 FR 25202 - Action Affecting Export Privileges; Orion Air, S.L. and Syrian Pearl Airlines; Order Renewing...

    Science.gov (United States)

    2010-05-07

    ... DEPARTMENT OF COMMERCE Bureau of Industry and Security Action Affecting Export Privileges; Orion Air, S.L. and Syrian Pearl Airlines; Order Renewing Order Temporarily Denying Export Privileges Orion... Denying the Export Privileges of Respondents Orion Air, S.L. (``Orion Air'') and Syrian Pearl Airlines...

  4. The Career Cost: Does It Pay for a Military Pilot to Leave the Service for the Airlines?

    Science.gov (United States)

    2015-06-01

    airline pilot compensation: Alaska, American, Delta Airlines, FedEx, Frontier, Hawaiian, JetBlue, Southwest, Spirit, United, UPS, and Virgin America...continue to receive pay after reaching 65 years old, and the veteran loses their source of income. If the retiree lived to be 90 years old, then they

  5. An Airline-Based Multilevel Analysis of Airfare Elasticity for Passenger Demand

    Science.gov (United States)

    Castelli, Lorenzo; Ukovich, Walter; Pesenti, Raffaele

    2003-01-01

    Price elasticity of passenger demand for a specific airline is estimated. The main drivers affecting passenger demand for air transportation are identified. First, an Ordinary Least Squares regression analysis is performed. Then, a multilevel analysis-based methodology to investigate the pattern of variation of price elasticity of demand among the various routes of the airline under study is proposed. The experienced daily passenger demands on each fare-class are grouped for each considered route. 9 routes were studied for the months of February and May in years from 1999 to 2002, and two fare-classes were defined (business and economy). The analysis has revealed that the airfare elasticity of passenger demand significantly varies among the different routes of the airline.

  6. ASPECTS OF MARKETING APPLICATION WITHIN AIRLINE TRAVELLING COMPANIES. THE CASE OF ALBANIA

    Directory of Open Access Journals (Sweden)

    Areti STRINGA

    2008-06-01

    Full Text Available The objectives of the research were defined through the following tasks: 1. To synthesise the features of daily marketing activities of the airlines operating on the Albanian market and establish their strengths and weaknesses. 2. To analyse and establish if there are marked differences in marketing activities of the airlines operating on the Albanian market. Different sources of primary and secondary data were used in analysis of services marketing of airlines operating on the Albanian market. The nature of the research was exploratory. Primary data were mostly gathered from expert opinion by means of personal interviews. The depth interviews took place in offices of the respondents.

  7. Working hours associated with unintentional sleep at work among airline pilots

    Directory of Open Access Journals (Sweden)

    Elaine Cristina Marqueze

    Full Text Available ABSTRACT OBJECTIVE Tto identify factors associated with unintentional sleep at work of airline pilots. METHODS This is a cross-sectional epidemiological study conducted with 1,235 Brazilian airline pilots, who work national or international flights. Data collection has been performed online. We carried out a bivariate and multiple logistic regression analysis, having as dependent variable unintentional sleep at work. The independent variables were related to biodemographic data, characteristics of the work, lifestyle, and aspects of sleep. RESULTS The prevalence of unintentional sleep while flying the airplane was 57.8%. The factors associated with unintentional sleep at work were: flying for more than 65 hours a month, frequent technical delays, greater need for recovery after work, work ability below optimal, insufficient sleep, and excessive sleepiness. CONCLUSIONS The occurrence of unintentional sleep at work of airline pilots is associated with factors related to the organization of the work and health.

  8. Modelling altered fractionation schedules

    International Nuclear Information System (INIS)

    Fowler, J.F.

    1993-01-01

    The author discusses the conflicting requirements of hyperfractionation and accelerated fractionation used in radiotherapy, and the development of computer modelling to predict how to obtain an optimum of tumour cell kill without exceeding normal-tissue tolerance. The present trend is to shorten hyperfractionated schedules from 6 or 7 weeks to give overall times of 4 or 5 weeks as in new schedules by Herskovic et al (1992) and Harari (1992). Very high doses are given, much higher than can be given when ultrashort schedules such as CHART (12 days) are used. Computer modelling has suggested that optimum overall times, to yield maximum cell kill in tumours ((α/β = 10 Gy) for a constant level of late complications (α/β = 3 Gy) would be X or X-1 weeks, where X is the doubling time of the tumour cells in days (Fowler 1990). For median doubling times of about 5 days, overall times of 4 or 5 weeks should be ideal. (U.K.)

  9. Estimating exponential scheduling preferences

    DEFF Research Database (Denmark)

    Hjorth, Katrine; Börjesson, Maria; Engelson, Leonid

    Extended abstract Choice of departure time is a travel choice dimension that transportation planners often need to forecast in appraisal. A traveller may shift departure time in response to changes in expected travel time or travel time variability (TTV) or in response to time-differentiated cong......Extended abstract Choice of departure time is a travel choice dimension that transportation planners often need to forecast in appraisal. A traveller may shift departure time in response to changes in expected travel time or travel time variability (TTV) or in response to time...... from the underlying scheduling preferences (Noland and Small, 1995, Bates et al., 2001, Fosgerau and Karlström, 2010). The scheduling preferences can be formally represented as time-dependent rates of utility derived at different locations. Assuming that the travellers are rational and choose departure......’ departure time choice. The assumption underlying the scheduling approach is that the traveller rationally maximises her total utility obtained during a period of time. The total utility depends on time of departure from the origin and time of arrival to the destination. The total utility is usually assumed...

  10. Financial Comparisons across Different Business Models in the Canadian Airline Industry

    Science.gov (United States)

    Flouris, Triant; Walker, Thomas

    2007-01-01

    This paper examines the accounting and stock price performance of two Canadian airlines, WestJet and Air Canada, over a five year period, taking into account the aftermath of the systemic shock to the airline industry produced by the September 11, 2001 (9-11), terrorist attacks and subsequent events such as the 2002 SARS outbreak, the wars in Afghanistan and Iraq, and the accompanying rise in jet fuel prices. Our study focuses on the viability of low-cost versus conventional-cost business models in Canada under the current business environment and the ability of airlines to withstand and effectively respond to catastrophic industry events. Furthermore, we link the effectiveness of the airlines responses to these events to specific elements of their respective business models. We test our hypothesis through a case study. We focus on WestJet as a typical low-cost airline and compare its accounting and stock performance to Air Canada, a legacy carrier and rival in several business sectors. We find WestJet to be much less affected by catastrophic industry events. By decomposing each airline s return volatility, we observe that WestJet s systematic and unsystematic risk increased only slightly during the industry's post-9-11 turmoil when compared to Air Canada. In addition, we find that both WestJet s accounting and stock performance have been highly superior to those of Air Canada. We argue that WestJet s business model provides the firm with significantly more financial and operational flexibility than its legacy rival, Air Canada. WestJet's lower operating costs, high consumer trust, product offering, corporate structure, workforce and work practices, as well as operational procedures are all factors that appear to contribute to its relative success.

  11. 75 FR 43564 - TA-W-71,483, Continental Airlines, Inc., Reservations Division, Houston, TX; TA-W-71,483A...

    Science.gov (United States)

    2010-07-26

    ... DEPARTMENT OF LABOR Employment and Training Administration TA-W-71,483, Continental Airlines, Inc., Reservations Division, Houston, TX; TA-W-71,483A, Continental Airlines, Inc., Reservations Division, Tampa, FL; TA-W-71,483B, Continental Airlines, Inc., Reservations Division, Salt Lake City, UT; Notice of...

  12. The Low Cost Airline Consumer Price Sensitivity. An Investigation on The Mediating Role of Promotion and Trust in Brand

    Directory of Open Access Journals (Sweden)

    Janfry Sihite

    2014-12-01

    Full Text Available The ASEAN Open Sky Policy is one of ASEAN policy to open the airspace between the ASEAN member countries. Aviation services based companies including the Low Cost airlines will experience tight com-petition among ASEAN airline companies. This research aim to explore the effect of price on customer loyalty through the mediating role of promotion and trust in brand. The original sample collected from 100 Indonesian low-cost airline Citilink consumer that just arrived in Soekarno-Hatta International Airport, the bootstrapped techniques conducted for 500 sub-samples and further analyzed with structural equation modelling partial least square. The research findings support the low cost airline consumer price sensitivity, furthermore price affect the trust in brand more severe compared with the promotion. Price effect fully mediated through the trust in brand and promotion toward the consumer loyalty. Further research should consider the sensitivity of price to elaborate the decision making process for the low cost airline consumer.

  13. An evaluation of airline beta values and their application in calculating the cost of equity capital.

    OpenAIRE

    Turner, Sheelah; Morrell, Peter

    2003-01-01

    This paper focuses on the calculation of the cost of equity capital in a sample of airlines, in comparison to industry-calculated values. The approach usually taken is to apply the Capital Asset Pricing Model to airline stock prices and market indices. The research shows that the calculated b values are sensitive to the precise methodology and calculations used. Further, the low regression model fits indicate the Capital Asset Pricing Model may not be the most suitable model for b value calcul...

  14. Competition in the Malaysian Airline Industry: An Exploratory Study using Game-Theoretical and Empirical Analysis

    OpenAIRE

    Ho, Kevin Swee Aun

    2005-01-01

    The competitive landscape of the Malaysian airline industry is facing changes due to the presence of a low-cost carrier, AirAsia. AirAsia has gain much market share by introducing low-fares much to the expense of the national carrier, MAS. Due to the increased competition, the national carrier must react in order to stop the decline of its domestic operations. This aim of this study is to understand the strategies of the two dominant carriers in the Malaysian airline industry, MAS and AirAsia...

  15. Specifications and test procedures for airline-type supplied-air suits

    International Nuclear Information System (INIS)

    Revoir, W.H.; Pritchard, J.A.; Davis, T.O.; Richards, C.P.; Wheat, L.D.

    1975-05-01

    Procedures and requirements have been established to permit airline-type supplied-air suits needed by contractors of the Energy Research and Development Administration to be tested for performance by the Respirator Research and Development Section, Industrial Hygiene Group, of the Los Alamos Scientific Laboratory, and to have the adequacy of the performance of these devices evaluated by the Los Alamos Scientific Laboratory Respirator Advisory Committee. Test equipment, test methods, and performance criteria for airline-type supplied-air suits are prescribed. (U.S.)

  16. Journal of Airline and Airport Management: Taking off on an exciting journey into Air Transport Research

    Directory of Open Access Journals (Sweden)

    David Gonzalez-Prieto

    2011-11-01

    Full Text Available We are pleased to introduce this first and inaugural issue of the first volume of the Journal of Airline and Airport Management (JAIRM. JAIRM is an international journal that proposes and fosters discussion on the theory and application in all areas of air transport, including (but not limited to air transport and globalization, airline and airport management. We are interested in issues related to production, logistics, operations, marketing, policy and regulation, information systems, project management, quality, as well as regional development, economics, organizational behaviour, finance and accounting in air transport research.

  17. Effect of airline travel on performance: a review of the literature.

    Science.gov (United States)

    Leatherwood, Whitney E; Dragoo, Jason L

    2013-06-01

    The need for athletes to travel long distances has spurred investigation into the effect of air travel across multiple time zones on athletic performance. Rapid eastward or westward travel may negatively affect the body in many ways; therefore, strategies should be employed to minimise these effects which may hamper athletic performance. In this review, the fundamentals of circadian rhythm disruption are examined along with additional effects of airline travel including jet lag, sleep deprivation, travel at altitude and nutritional considerations that negatively affect performance. Evidence-based recommendations are provided at the end of the manuscript to minimise the effects of airline travel on performance.

  18. On program restructuring, scheduling, and communication for parallel processor systems

    Energy Technology Data Exchange (ETDEWEB)

    Polychronopoulos, Constantine D. [Univ. of Illinois, Urbana, IL (United States)

    1986-08-01

    This dissertation discusses several software and hardware aspects of program execution on large-scale, high-performance parallel processor systems. The issues covered are program restructuring, partitioning, scheduling and interprocessor communication, synchronization, and hardware design issues of specialized units. All this work was performed focusing on a single goal: to maximize program speedup, or equivalently, to minimize parallel execution time. Parafrase, a Fortran restructuring compiler was used to transform programs in a parallel form and conduct experiments. Two new program restructuring techniques are presented, loop coalescing and subscript blocking. Compile-time and run-time scheduling schemes are covered extensively. Depending on the program construct, these algorithms generate optimal or near-optimal schedules. For the case of arbitrarily nested hybrid loops, two optimal scheduling algorithms for dynamic and static scheduling are presented. Simulation results are given for a new dynamic scheduling algorithm. The performance of this algorithm is compared to that of self-scheduling. Techniques for program partitioning and minimization of interprocessor communication for idealized program models and for real Fortran programs are also discussed. The close relationship between scheduling, interprocessor communication, and synchronization becomes apparent at several points in this work. Finally, the impact of various types of overhead on program speedup and experimental results are presented.

  19. NRC comprehensive records disposition schedule

    International Nuclear Information System (INIS)

    1982-07-01

    Effective January 1, 1982, NRC will institute records retention and disposal practices in accordance with the approved Comprehensive Records Disposition Schedule (CRDS). CRDS is comprised of NRC Schedules (NRCS) 1 to 4 which apply to the agency's program or substantive records and General Records Schedules (GRS) 1 to 22 which apply to housekeeping or facilitative records. The schedules are assembled functionally/organizationally to facilitate their use. Preceding the records descriptions and disposition instructions for both NRCS and GRS, there are brief statements on the organizational units which accumulate the records in each functional area, and other information regarding the schedules' applicability

  20. Practical quantum appointment scheduling

    Science.gov (United States)

    Touchette, Dave; Lovitz, Benjamin; Lütkenhaus, Norbert

    2018-04-01

    We propose a protocol based on coherent states and linear optics operations for solving the appointment-scheduling problem. Our main protocol leaks strictly less information about each party's input than the optimal classical protocol, even when considering experimental errors. Along with the ability to generate constant-amplitude coherent states over two modes, this protocol requires the ability to transfer these modes back-and-forth between the two parties multiple times with very low losses. The implementation requirements are thus still challenging. Along the way, we develop tools to study quantum information cost of interactive protocols in the finite regime.