Search Results (11)

The increasing global demand for air travel over the past three decades has led to heightened congestion, environmental concerns, and operational inefficiencies. This study explores the potential of commercial aircraft formation flight, inspired by the energy-saving flight patterns of migratory birds, to enhance fuel efficiency on the busy Melbourne to Sydney city-pair route. The methodology is divided into macroscopic and microscopic levels, addressing both strategic planning and detailed flight optimisation. The macroscopic level focuses on route optimisation, formation flight planning, air traffic management integration, and environmental impact. The microscopic level involves adjustments to individual aircraft flight profiles to ensure minimum separation, flight safety, and efficiency. Using a gradient-based optimisation algorithm applied to a constrained nonlinear multivariable function, this study aims to minimise fuel consumption and travel time while maintaining the required separation distances. The mathematical formulation and algorithm pseudocode provides a clear framework for implementation. The experimental results demonstrate the potential of formation flight to optimise fuel efficiency and resolve path conflicts on the Melbourne to Sydney route; despite a conservative 5% fuel efficiency improvement for the follower aircraft, the total fuel consumption decreased by 2.5–2.65% compared to the non-formation flight. These findings support the feasibility of applying formation flight principles to commercial aviation in Australia for improved fuel efficiency and operation performance of busy short-haul routes. Full article

To reduce the carbon footprint of transport, policymakers are simultaneously stimulating cleaner vehicles and more sustainable mobility choices, such as a shift to rail for short-haul flights within Europe. The purpose of this study is to determine the climate impact of a journey within Europe by aircraft, train or passenger car, and to better understand what factors drive this impact in order to make smarter and more sustainable fact-based mobility choices. The study consists of a life cycle inventory (LCI) and life cycle impact assessment (LCA) of greenhouse gas emissions of specific vehicles in five case study travel scenarios in Europe. The energy and resulting direct emissions (including non-CO₂) of the aircraft scenarios were calculated for the purpose of this study using the Mission Aircraft and Systems Simulation tool developed by the Royal Netherlands Aerospace Centre NLR. For other LCA phases and other modes of transport, the study relies on emission factors from public literature. A trip by train results in three to five times less emissions than a comparable trip by aircraft. In most scenarios, the passenger car with two people onboard emits significantly more than a train but slightly less than an aircraft. The study also shows what drives the climate impact of such a trip and how this is very different for different modes of transport. The study further highlights a lack of high-quality data, especially in the areas of indirect emissions and infrastructure, poor consistency among studies and a general under-documentation and lack of transparency regarding assumptions. Full article

With a focus on disease prevention and health promotion, a reactive and disease-centric healthcare system is revolutionized to a point-of-care model by the application of wearable devices. The convenience and low cost made it possible for long-term monitoring of health problems in long-distance traveling such as flights. While most of the existing health monitoring systems on aircrafts are limited for pilots, point-of-care systems provide choices for passengers to enjoy healthcare at the same level. Here in this paper, an airline point-of-care system containing hybrid electrocardiogram (ECG), breathing, and motion signals detection is proposed. At the same time, we propose the diagnosis of sleep apnea-hypopnea syndrome (SAHS) on flights as an application of this system to satisfy the inevitable demands for sleeping on long-haul flights. The hardware design includes ECG electrodes, flexible piezoelectric belts, and a control box, which enables the system to detect the original data of ECG, breathing, and motion signals. By processing these data with interval extraction-based feature selection method, the signals would be characterized and then provided for the long short-term memory recurrent neural network (LSTM-RNN) to classify the SAHS. Compared with other machine learning methods, our model shows high accuracy up to 84–85% with the lowest overfit problem, which proves its potential application in other related fields. Full article

Prior to the COVID-19 pandemic, tourism had permeated all spaces of experience, reaching nearly every country, region, community, and corner of the globe. In recent decades, the meanings, implications, and roles of tourism have also expanded significantly. This article focuses on unconventional tourism mobilities, including same-day visits, which are an important but often neglected part of the tourism system, constantly challenging both scholars and tourism industry stakeholders. Unconventional tourism is an umbrella term that covers most kinds of unregistered or unaccounted tourist mobilities, some of which might not appear to be ‘tourism’ but should be in certain localities and under certain conditions. Given the growth of unregistered tourist flows and unaccounted leisure (or utilitarian) mobilities, there is a need in tourism studies to apply innovative research methods and to reconceptualize the meanings of tourism in different geographical and social contexts. It is expected that people’s desire to travel in the post-pandemic era will educe new spatial and temporal travel experiences and behaviours in which unconventional tourisms will play an important role. To better understand this phenomenon and to evaluate the development of new approaches to travel and behavioural spatialities, new ways of thinking, new theoretical constructs, and new methodologies are needed. This article seeks to explore certain hidden or invisible tourism mobilities, focusing on the geographical patterns, processes, and hidden aspects of unconventional tourism. Full article

Recently, there has been much interest in measuring the environmental impact of short-to-medium-haul flights. Emissions of CO₂ are usually measured to consider the environmental footprint, and CO₂ calculators are available using different types of approximations. We propose analytical models calculating gate-to-gate CO₂ emissions and travel time based on the flight distance and on the number of available seats. The accuracy of the numerical results were in line with other CO₂ calculators, and when applying an analytical fitting, the error of interpolation was low. The models presented the advantage with respect to other calculators of being sensitive to the number of available seats, a parameter generally not explicitly considered. Its applicability was shown in two practical examples where emissions and travel time per kilometre were calculated for several European routes in a simple and efficient manner. The model enabled the identification of routes where rail would be a viable alternative both from the emissions and total travel time perspectives. Full article

There are two key parameters in short-haul truck operations to deliver biomass to a biorefinery: (1) mass of the load and (2) cycle time (load, travel, unload, and return). A plan to optimize both these parameters is outlined in this study. Operation of a logistics system to deliver 20-bale racks to a biorefinery for continuous 24/7 operation, 48 weeks/year is described. Round bales are stored in satellite storage locations (SSLs) by feedstock producers. A truckload consists of two tandem trailers (40, 0.4 Mg bales), a specification that maximizes load mass. Load-out at the SSL (loading bales into racks) is performed by a contractor and paid by the biorefinery. Subsequent hauling (truck tractor to pull the trailers) is also contracted for by the biorefinery. Central control is specified; the “feedstock manager” at the biorefinery decides the order SSLs are loaded out and can route a truck to any SSL where a load is ready. Tandem trailers with empty racks are dropped at the SSL, and the trailers with full racks are towed to the biorefinery. Uncoupling the loading and hauling in this manner reduces the time the truck waits for loading and the SSL load-out waits for a truck; thus, productivity of both operations is increased. At the biorefinery receiving facility, full racks are removed from the trailers and replaced with empty racks. The objective for this transfer is a 10 min unload time, which completes a logistics design that minimizes cycle time. A delivered rack is placed in a rack unloader to supply bales for immediate processing, or it is placed in central storage to supply bales for nighttime and weekend operations. Three biorefinery capacities were studied: 0.5, 1.0, and 1.5 bale/min. The analysis shows that rack cost to supply a biorefinery processing a bale/min for 24/7 operation is ~3.00 USD/Mg of annual biorefinery capacity, and the rack trailer cost is ~3.25 USD/Mg. Total delivery cost, beginning with bales in SSL storage and ending with a rack being placed in an unloader to deliver individual bales for processing, is 31.51, 28.42, and 26.92 USD/Mg for a biorefinery processing rates of 0.5, 1.0, and 1.5 bale/min, respectively. Full article

The COVID-19 outbreak has restricted international travel, halting tourism globally. Thus, travel demand has shifted from international to domestic destinations. The prolonged travel restriction has changed travel trends and travelers’ behaviors, adversely affecting the tourism industry worldwide. This study attempted to understand and examine the changes in travel preferences, such as choice of destinations, activities, and transportation modes, following the COVID-19 outbreak. This study used primary survey data of 200 respondents collected in June 2020 and secondary survey data collected by the Korea Tourism Organization in 2015 and 2017. The study also examined the role of the government in supporting strategies to prepare for the post-COVID tourism landscape. The analysis showed that the pandemic has caused travelers to favor short-haul destinations where non-contact (socially distanced) travel is possible. The study also found that the distributed land strategy that can make “untact” tourism a possibility could boost the struggling tourism industry. Full article

The microclimate of an airline cabin consists of dry, recirculated, and cool air, which is maintained at lower pressure than that found at sea level. Being exposed to this distinctive, encapsulated environment for prolonged durations, together with the short-term chair-rest immobilization that occurs during long-haul flights, can trigger distinct and detrimental reactions to the human body. There is evidence that long-haul flights promote fluid shifts to the lower extremity and induce changes in blood viscosity which may accelerate dehydration, possibly compromising an athlete’s potential for success upon arrival at their destination. Surprisingly, and despite several recent systematic reviews investigating the effects of jet lag and transmeridian travel on human physiology, there has been no systematic effort to address to what extent hypohydration is a (health, performance) risk to travelers embarking on long journeys. This narrative review summarizes the rationale and evidence for why the combination of fluid balance and long-haul flight remains a critically overlooked issue for traveling persons, be it for health, leisure, business, or in a sporting context. Upon review, there are few studies which have been conducted on actual traveling athletes, and those that have provide no real evidence of how the incidence rate, magnitude, or duration of acute dehydration may affect the general health or performance of elite athletes. Full article

China’s international air transportation has experienced tremendous growth and major reforms over the past two decades. While there has been a considerable discussion on the evolution of China’s domestic aviation market, studies on China’s international aviation markets have been limited. This paper first describes the historical development of China’s international aviation market and then, based on actual origin/destination (O/D) passenger flow data, explores the relevant evolution of China’s international air networks from the perspectives of the spatial distribution of international air networks and clustering characteristics of international air passengers. The development of China’s international aviation market can be attributable to the deregulation process in China’s aviation market and a broad “opening up” strategy in the global forum after 1990. Due to China’s proximity to East Asia and Southeast Asia, China’s international air networks show an obvious clustering pattern for short and medium-haul travel in Asia. In addition, average international air travel distance, institutional and policy changes, and increasing foreign trade and foreign tourism are crucial for the expansion of China’s international air networks. Full article

Air travel requirements are a concern for National Basketball Association (NBA) coaches, players, and owners, as sport-based research has demonstrated short-haul flights (≤6 h) increase injury risk and impede performance. However, examination of the impact of air travel on player health and performance specifically in the NBA is scarce. Therefore, we conducted a narrative review of literature examining the influence of air travel on health and performance in team sport athletes with suggestions for future research directions in the NBA. Prominent empirical findings and practical recommendations are highlighted pertaining to sleep, nutrition, recovery, and scheduling strategies to alleviate the negative effects of air travel on health and performance in NBA players. Full article

The travelling population is increasing globally year on year. International tourist arrival figures reached 1087 million in 2013 and 1133 million in 2014; of which 53% and 54% respectively accounted for air transport. The water on board aircraft is sourced from surface or ground water; piped to a central filling point and distributed to each aircraft by water service vehicles at the home base or at the destination airport. The purpose of this study was to ascertain the microbial, chemical (pH; Total and Free chlorine) and physical (temperature) quality of water from two aircraft, long- and short-haul, as well as from the original water source and the water service vehicle. A total of 154 water samples were collected and analysed. Long-haul flights were found to be significantly poorer in terms of microbial quality than short haul flights (p = 0.015). Furthermore, correlation and regression analysis showed that the water service vehicle was a significant source of increased microbial load in aircraft. Microbial diversity was also demonstrated, with 37 bacterial species identified belonging to eight classes: γ-Proteobacteria; β-Proteobacteria; α-Proteobacteria; Bacilli; Actinobacteria; Flavobacteria; Sphingobacteria and Cytophaga; using phenotypic and 16S rDNA sequence-based analysis. We present a novel quantified study of aircraft-related potable water supplies. Full article