9 research outputs found
Out of the spotlight: Four years of Italian coach market prices
No full textAnalogous to Germany and France, Italian coach market radically changed after liberalisation (2014). Liberalisation led to new routes, increased frequencies, mergers, and withdrawals. The paper analyses market trends from four years of real ticket prices collected through collaboration with www.checkmybus.it. The dataset, consisting of monthly average prices and the number of clicks by company and by city-pair, is enriched with spatial information, including the separation of airport routes. Results show that sub-national markets had different trends, with the growth of offer on routes linked to network expansion of the early liberalisation slowing down. Contrarily, the historical routes to the Centre and South remain stable. Interestingly, larger (Top-5) companies' prices are below market average up to 5–10% less. Smaller companies operate often on niche routes, with fewer economies of scale and thus maintain higher prices. This trend switched during the COVID pandemic. A further comparison with rail prices showed that coaches were able to reduce the price gap at least with conventional trains, from −50% (average for 2017–2020) to −20% for the second semester of 2020. This is a sign of the ability of the coach sector to adapt to the shock, by reducing capacity and concentrating on more competitive routes
Long-distance rail in Europe: Comparing the forms of head-on competition across Europe
No full textEurope is finally entering a season of liberalisation in the long-distance rail passenger market, which takes the form of on-track competition among public and private operators. The paper provides a broad-scope comparison of relevant European markets, belonging to liberalised and non-liberalised countries, aiming to point out the patterns in terms of supply, competition model and prices. The paper is based on a sample of heterogeneous 69 city-pairs, analysed in two fourteen days periods in 2019 (May/June and November). All available modes are observed, collecting info on companies, frequency of services, and cheapest price. The analysis starts from a schematisation of different business models, based on literature. Then, using the database, we study the country's supply structure, size, and level of intermodal and intra-modal competition through HHIs. Prices are analysed in two steps: the average prices and the price dispersion, searching for their main determinants, including but not limited to competition. Results show that a higher competition level is not always corresponding to low prices, which are instead determined by many other factors such as size of market, demand, socio-economic characteristics, subsidies, production costs, speed advantage, strength of the incumbent, etc. The competition level, instead, directly influences the quality, the supplied capacity, and the price dispersion
Evaluating the interaction between engineered materials and aircraft tyres as arresting systems in landing overrun events
No full textAccording to the registered databases of air accidents around the world, landing overruns are the most probable accidents among all runway excursion events. Although new aircraft are enhanced with the latest technologies that improve the maneuvers safety, the frequency of landing overruns are bound to increase because of the ascending growth rate of annual traffic. The principal scope of this paper is to evaluate the functionality of Engineered Materials Arresting System (EMAS) as a mitigation strategy to reduce the possible consequences of landing overrun events and in particular to determine if installing an EMAS can help land-locked airports to meet Federal Aviation Administration (FAA) recommendations in order to upgrade their Runway End Safety Areas (RESAs). In the previous studies, not enough investigations are dedicated to predicting the behavior of the aircraft and its deceleration rate after interfering EMAS and how different materials as arrestor beds would modify aircraft braking distance in RESA. Therefore, secondary objective of this paper is to determine the most optimum height of EMAS slabs, in function of execution costs and accident severity reduction rate. In this regard, a MATLAB®-based numerical code, which simulate the tire-pavement interface, is developed in order to evaluate the functionality of EMAS for aircraft ground maneuvers. Although this code is developed for both dry and wet runway conditions, dry runway's surface is selected as the boundary condition of this study. It simulates aircraft arresting distance by calculating a dynamic skid resistance between aircraft main gear and runway pavement with a fix time step. The results are plotted as risk contour intervals on the layout of EMAS that is installed at the RESA. In addition, this numerical code is adopted in order to perform a sensitivity analysis on five arresting bed materials, which consist of three low-density concretes with maximum crushing stress thresholds of 172500, 345000 and 930000 Pa, one gravel-based material and one foam aggregate-based mixture. Among all, low-density concrete with the highest crushing strength causes shorter aircraft arresting distance
Non-Linear Characterisation of Kevlar and Silicon Carbide Fibres for Structural Health Monitoring Applications
No full textUncertainties about the long term bearing capacity of aramid fibres have made designers reluctant to utilize them for external pre-stressing for cable-stayed bridges. Recent research carried out on cable-stayed bridges has found that the steel cables, although well protected from the external environment, are subject to corrosion, resulting in a risk of structural defects and malfunctions. The question that prompted this study is whether simple and non-destructive non-linearity tests can be used for assessing structural damage in aramid fibres or elements. The concept is to detect weak non-linearities in the dynamic response measured on fibres and ropes and to use the level of non-linearity as an indicator for evaluating the residual life span of aramid elements, cables and ropes. In perspective, a non-linearity test may be easily integrated in structural health monitoring protocols to be employed on aramid cables and elements to collect timely notifications about possible anomalies in the structural behaviour. In order to investigate the sensitivity of such an approach to structural health monitoring, non-linearity characterisation tests were conducted on aramid fibres by applying controlled sweep-sine excitations at different loading levels. In order to have a comparative term and to test the setup machine, a similar characterisation procedure was also applied to a novel material, the silicon carbide, which is known to exhibit a purely brittle behaviour, with no appreciable plastic deformatio
Targeted Analysis // IMAGINE. Developing a metropolitan-regional imaginary in the Milano-Bologna urban region
No full textESPON 2021, TARGETED ANALYSIS, IMAGINE Developing a metropolitan-regional imaginary in the Milano-Bologna urban region Final Report
No full textNon-Linear Characterisation of Kevlar and Silicon Carbide Fibres for Structural Health Monitoring Applications
No full textСовременные методы предотвращения выкатываний воздушных судов за пределы взлетно-посадочной полосы
No full textThe landing of the aircraft has always been the most challenging and dangerous stage of the flight. In order to make a safe landing, the aircraft (A/C) requires reducing the vertical (at the stage of flare-out) and horizontal (prior to touchdown) components of the aircraft's flight speed vector, which in turn reduces the capabilities to increase lift and limits the crew's ability to perform maneuvers. At the same time, during landing the crew must align the aircraft with the runway (RW) and make a touchdown, subsequent A/C landing roll and stop within a rather limited area, which eventually and particularly, under the effect of contributing adverse factors (piloting errors, wind shear, icing, engine failure, aquaplaning, etc.) can cause the aircraft to overshoot and overrun the RW. Currently, as the analysis of aviation accidents statistics shows, the issue of preventing and alerting aircraft overrun is quite relevant. The search for a solution, in terms of preventing aircraft overrunning the runway (RW), is conducted as at the level of aviation authorities as among aircraft manufacturers, operators. Within the framework of this review, an attempt is made to identify and analyze the key factors affecting the dynamics of aircraft motion during landing, using information about aviation accidents that have occurred over the past few years. Notably, such aspects as a human factor and technical features of the operation of modern jet aircraft, influencing the A/C landing roll, are considered. In addition, special attention is paid to consider the methods of prevention and warning of A/C overrun with highlighting the approaches of passive and active protection. Within the framework of the analysis of active protection techniques, the principles of on-board avionic systems operation of the most major aircraft manufacturers, such as Boeing and Airbus, are considered. As an example of the passive protection, the experience of using special energy-absorbing destructible blocks installed next to the runway threshold, is analyzed.Посадка воздушного судна была и остается наиболее сложным и опасным этапом полета. Для совершения безопасной посадки воздушному судну (ВС) необходимо уменьшить вертикальную (на этапе выравнивания)и горизонтальную (на этапе выдерживания) составляющие вектора скорости полета ВС, что в свою очередь уменьшает возможности по увеличению подъемной силы и ограничивает экипаж в возможностях совершения маневров. Также экипаж во время посадки должен подвести ВС к взлетно-посадочной полосе (ВПП) и совершить касание, последующие пробег и остановку ВС в пределах довольно ограниченной по своим размерам площадки, что в конечном итоге, в частности при воздействии сопутствующих неблагоприятных факторов (ошибки пилотирования, сдвиг ветра, обледенение, отказ двигателя, гидроглиссирование и др.), может привести к перелету и выкатыванию самолетов за пределы ВПП. В настоящее время вопрос возможности предотвращения и предупреждения выкатываний ВС, как показывает анализ статистики авиационных происшествий, достаточно актуален. Поиск решения в части предотвращения выкатываний ВС за пределы ВПП ведется как на уровне авиационных властей, так и на уровнях производителей и эксплуатантов ВС. В рамках данной обзорной статьи предпринята попытка выделить и проанализировать ключевые факторы, влияющие на динамику движения ВС при посадке, используя информацию об авиационных происшествиях, произошедших за последние несколько лет. В частности, рассмотрены такие аспекты, как человеческий фактор и технические особенности работы современных реактивных ВС, влияющие на пробег самолета по полосе. Кроме того, особое внимание в статье уделено рассмотрению методов предотвращения и предупреждения выкатываний ВС с выделением методов пассивной и методов активной защиты. В рамках анализа методов активной защиты рассмотрены принципы работы бортовых электронных систем крупнейших авиапроизводителей, таких как Boeing и Airbus. В качестве примера пассивной защиты проанализирован опыт использования специальных энергопоглощающих разрушаемых блоков, размещаемых после торца ВПП
