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The control of air flow fields generated in the textile manufacturing process is important to fiber motion. With the expansion of textile applications and the challenges brought by carbon emissions, a series of fundamental research has been conducted on the control of various forms of air flow fields in textile processes. This paper reviews the research on air flow fields and fiber motion in textile processes over the past few decades, focusing on both experimental and numerical studies. The air flow field characteristics, fiber motion patterns, and corresponding control methods for vortex, jet and shear flow fields in the textile process are summarized. The results show that the air flow field and fiber motion are major factors affecting textile structure. These fundamental studies are of great significance in improving product quality, reducing energy consumption, and exploring novel applications. [ABSTRACT FROM AUTHOR]

Aircraft deicing/anti-icing fluids (ADFs) are applied to remove and prevent icing on aircraft during taxi and takeoff. The Dallas-Fort Worth (DFW) International Airport uses deicing pads for deicing activities that collect and contain the spent deicing fluids for proper treatment or disposal. Local waterways receive ADF as "drip and shear" during the aircraft taxi on the runway and then takeoff. The glycol-based ADF serves as a nutrient for bacteria that grow exponentially, deplete dissolved oxygen (DO) from receiving waterways, and subsequently kill aquatic life. In this paper, we present a data-driven discrete-event simulation modeling process developed in collaboration with DFW Airport to assess aircraft assignment strategies to deicing pad locations by monitoring impact on DO. Our process consists of the following phases: (1) Data Collection, (2) Probability Distribution Modeling, and (3) State Transition Modeling. Both Phases (2) and (3) utilized data mining approaches, including treed regression and variable selection via false discovery rate. Detailed implementation of these phases is described for the DFW Airport case study, and the DFW Airport deicing activities simulation tool framework is presented. The actual data and simulation results were compared in terms of the DO levels in airport receiving waterways to verify the model validity after implementing the proposed model for DFW. Thus, the proposed model can be implemented by airports to control and minimize the adverse environmental effects resulting from deicing activities by optimizing the aircraft assignment to the pad locations. [ABSTRACT FROM AUTHOR]

This paper discusses a possibility to evolve the current Air Traffic Flow and Capacity Management towards a more proactive approach. This new method focuses on reducing the expected probability of air traffic control intervention based on "hot spot" identification and mitigation at strategic level by applying subliminal changes on the times of arrival at the crossing or merging points (junctions). The concept is fully aligned with the trajectory-based operation principles. The approach assumes that the changes on the times of arrival only demand small speed changes from the involved aircraft. In this study, the hot spots are defined as clusters of aircraft expected to arrive to the junctions. Two aircraft are said to be in the same cluster if their proximity and closure rate are below a given threshold. Some exercises are proposed and solved by applying this method. The obtained results show its ability to remove the potential conflicts by applying simple linear programming. This approach seeks to change the current capacity limiting factor, established by the number of aircraft occupying simultaneously each sector, to another parameter where the level of traffic complexity, flowing towards junctions, is identified and mitigated at strategic level. The speed changes, used as the control variable and computed before or during the flight, are designed to provide an adjustment on aircraft's required time of arrival at the junctions in order to have a de-randomised and well-behaved (conflict free) traffic. This will enable improvements in airspace capacity/ safety binomial. It is recognised that this measure alone is unable to produce a conflict free airspace, and then other collaborative and coordinated actions, such as adjusting and swapping departing times at the departing airports (before the aircraft are taking off), offsetting some flights from nominal route, and allowing multi-agent separation management (while they are in flight) should be applied together with this method. [ABSTRACT FROM AUTHOR]

This paper provides a detailed examination of the construction of Hong Kong International Airport (HKIA). The paper begins by reviewing recent work which has reconceptualised how airports are understood in spatial terms. It then describes the development of Hong Kong’s new airport, discussing the spatial format of the new airport design at HKIA, and the relationship between aviation and non-aviation uses. Next, it examines the impact of the airport on the rapidly shifting territorial politics of Hong Kong and the Pearl River Delta within the wider Chinese state. The paper argues that this case study must be assessed as part of a wider project of state territorial restructuring. [ABSTRACT FROM PUBLISHER]

Understanding airports as both objects and agents of policymaking, this paper critically examines the policy mobilities of Singapore Changi Airport by exploring its constructions, travels, and consumptions as a ‘model airport’ within and beyond Singapore. The argument presented is twofold. First, a historical approach to policy mobility usefully highlights how contemporary policy flows cannot be understood in isolation from earlier historical travels or reduced to movements triggered primarily by processes of urban neoliberalism. Second, such sensibilities are especially vital when approaching Asian cities where modes of regulation are not straightforwardly neoliberal, but are also underpinned by diverse nationalist imperatives that filter into policymaking motivations. This paper also emphasises the complex path-dependent relationship shared by travelling models and their cities of origin, illustrating how such territorial linkages function to both enable and constrain policy travels, but are nevertheless difficult to detach from travelling models. [ABSTRACT FROM AUTHOR]

This paper presents a nonlinear control strategy to stabilize the response of a floating platform in waves. The floating platform consists of multiple floating modules connected in sequence with flexible connectors. A nonlinear dynamic model with a number of controllers is developed for the stability control of the chain-shape floating structure. The backstepping method in conjunction with the Lyapunov stability criteria is proposed to derive the control law for each of the control actuators where the actuator forces are limited with output saturation. The numerical experiments illustrate the feasibility and effectiveness of the control strategy in various conditions of heading waves. The performance of the control method is discussed, especially associated with the saturated output. [ABSTRACT FROM AUTHOR]

This paper applies the dynamic panel data generalized method of moments estimator to the data on commercial passenger air traffic at all primary airports in the United States to evaluate the impact of traffic volume and number of destinations served with non-stop flights on the key indicators of regional economic development. We find that number of destinations served with non-stop flights has a much clearer and more robust impact on level of employment, number of business establishments, and average wage in the region. Passenger traffic volume affects employment and average wage, but not number of establishments. At the sample median, connecting a metropolitan statistical area with an extra destination, keeping everything else constant, creates 98 jobs and facilitates the opening of four new business establishments that employ people. The corresponding numbers for the sample mean are 223 jobs and 15 businesses. The impact of air travel on regional economic development is influenced by competition on the respective airline markets. [ABSTRACT FROM PUBLISHER]

The role of infrastructure as a factor of growth and development of countries and regions is often considered to be crucial. Among the various types of transport infrastructure, airports are considered as particularly strategic because of the increasing importance of air transport in connecting territories. This paper studies the impact of airports on Italian provinces. To this end, it builds on the framework proposed by Brueckner, where sectoral employment is regressed on a series of controls and on airline traffic. That framework is extended to take account of selection bias due to the location choices of airports and spatial spillover effects. It is found that the elasticity of service sector employment to airport passengers is 0.045 and that of spillover effects due to neighbouring airports is almost 0.017. [ABSTRACT FROM AUTHOR]

The paper examines the potential role that airfreight transport in the US can play in stimulating local and regional economic development. The analysis examines trends in employment and income for metropolitan statistical areas that make use of airfreight services. The focus is on causality, and not on simple correlation, and uses econometric analysis rather than simpler economic multiplier approaches. Granger causality testing based on panel data covering 35 airport and 32 metropolitan statistical areas in the US from 1990 to 2009 indicates that airfreight transport was a positive driver for local economic development. The conclusions focus on the strengths but also the weaknesses of the methodology for assessing causality. [ABSTRACT FROM PUBLISHER]

Algarve is a tourism region in the south of Portugal. This paper develops and empirically validates a second-order factor analysis model to assess the overall image of Algarve held by tourists who visit it. The data are based on the opinions of a random convenience sample of tourists taken at Faro Airport. It is found that the observable variables define three first-order factors - that is, three image factors - and these are used as indicators of a unique second-order factor, which is the overall image held by tourists to Algarve. The main conclusion of the paper is that the `sun and sand' factor is the most important determinant of tourists' overall image of the region. [ABSTRACT FROM AUTHOR]

In order to reduce the fiber diameter and the energy consumption in the meltblowing process, a modified slot die with two blocks was designed in this article. The numerical calculation and the experimental verification of the airflow field under the modified slot die were carried out, and the effect of the block structure parameters on the air field was investigated. The research results indicate that compared to the common slot die, the modified slot die with the blocks could increase the velocity on the spinning line and reduce the rate of the temperature decay on the spinning line. When the block width and the block inclination angle lower, and the block height expands, it could increase the peak of the air velocity, the temperature and the turbulence intensity on the center line of the air field under the modified slot die. The average velocity on the spinning line of the modified die under the conditions of block width = 20 mm, block height = 30 mm and block inclination angle = 60° is the highest. [ABSTRACT FROM AUTHOR]

Airport runways and taxiways have been identified as a key source of system-wide congestion and delay in the over-strained commercial air traffic system. To combat this growing problem, we present a novel approach for taxiway scheduling and traversal. Aircraft must traverse a taxiway, represented by a graph, from gates to their respective runways and arrive at their scheduled times while adhering to safety separation constraints. We describe a combinatorial mixed-integer linear program to determine the push-back time windows, aircraft speeds, stopping times, and in particular, traversal paths for a given graph and an imposed flight schedule as part of a single optimization problem. Safety and scheduling constraints are made robust to probabilistic deviations from the prescribed schedule and aircraft motion, and multiple objective functions are considered to examine the trade-off between taxi times and the probability of safety separation violation. Several scenarios are presented to demonstrate improvements gained from the method and possible uses for this approach. [ABSTRACT FROM AUTHOR]

The paraglider was conceived during the 1950s as a lightweight hybrid of parachute and inflated wing that might allow astronauts to pilot spacecraft to airfield landings. From 1961 to 1964, the US National Aeronautics and Space Administration (NASA) sought to convert the idea into a practical landing system for the Gemini spacecraft. The spacecraft would carry the paragilder safely tucked away through most of a mission. Only after re-entering the atmosphere from orbit would the crew deploy the wing. Having now converted their spacecraft into a makeshift gilder, they could fly to an airfield landing. How and why this ingenious scheme failed is the subject of this paper. [ABSTRACT FROM AUTHOR]

This study investigates the austerity HRM practices implemented in European airports during the economic crisis, the subsequent deterioration of working conditions and possible recovery policies. The survey results indicate that austerity HRM practices, especially work flexibility, increased workload and workplace discrimination, are strongly and positively correlated with work deterioration. Moreover, the impact of the crisis is not homogeneous across airports, since public airports and those located in South European regions and in countries displaying a high Economic Crisis Index suffer the most. Notwithstanding, a combination of micro-, meso - and macro -policies has the potential to alleviate the detrimental effects of the crisis on airport workplaces. [ABSTRACT FROM AUTHOR]

Automated parking systems play an important role in improving the utilization of parking facilities, particularly in busy public areas that receive many visitors, such as airports, government buildings, and shopping malls. The current parking facilities of airports in Saudi Arabia use barrier gates and ticket-issuing machines. Such parking facilities increase the waiting time at every circulation point, especially at the entry and exit terminals, and when a large number of vehicles are waiting in the queue. In this study, we address this problem by applying an automated technology at the entry/exit terminals of the current parking facilities. In particular, we introduce a parking system that uses radio-frequency identification (RFID) technology for the entry and exit terminals. The basic components of the current entry/exit system and the proposed one (i.e., using RFID technology) are described in detail. Subsequently, a simulation model for the entry/exit system using Arena 14.7 is developed to evaluate the current and proposed entry/exit systems. The evaluation is based on two performance metrics: average waiting time and average number of waiting vehicles. The developed simulation model is validated using actual data through a systematic procedure. The outcome of this study shows that the proposed RFID-based entry/exit system significantly outperforms the current system. Similarly, the validated results confirm the robustness of the simulation model. Thus, it can be concluded that an RFID-based parking system will provide an effective solution for parking facilities. [ABSTRACT FROM AUTHOR]

Automated borders promise instantaneous, objective and accurate decisions that efficiently filter the growing mass of mobile people and goods into safe and dangerous categories. We critically interrogate that promise by looking closely at how UK and European border agents reconfigure automated borders through their sense-making activities and everyday working practices. We are not interested in rehearsing a pro- vs. anti-automation debate, but instead illustrate how both positions reproduce a powerful anthropocentrism that effaces the entanglements and coordinations between humans and nonhumans in border spaces. Drawing from fieldwork with customs officers, immigration officers and airport managers at a UK and a European airport, we illustrate how border agents navigate a turbulent 'cycle' of automation that continually overturns assumed hierarchies between humans and technology. The coordinated practices engendered by institutional culture, material infrastructures, drug loos and sniffer dogs cannot be captured by a reductive account of automated borders as simply confirming or denying a predetermined, data-driven in/out decision. [ABSTRACT FROM AUTHOR]

Airfields are used in common polymer fiber spinning processes, such as melt blowing and spunbonding. A pair of louvers was installed in the air flow field of a melt blowing slot die. Previous research work has shown that, with louvers in place, the air velocity along the fiber threadline is higher than the velocity when louvers are not used. Since the air velocity is what drives the spinning process, the presence of louvers was expected to increase the attenuation of the molten filaments and thus improve the melt blowing process. Melt blowing runs were made with variable louver size (chord), louver separation, louver distance from the die face, the angle of the louvers relative to the die face, and air flow rate. Fibers were collected and fiber diameters were measured. [ABSTRACT FROM AUTHOR]

The direction and mechanisms of the relationship between airport traffic volumes and property prices are somewhat unclear in the literature. This study adds to that body of knowledge by empirically investigating the role of airports as an essential driver of economic activity by creating employment and facilitating air travel between destinations. The two-stage least-squares (2SLS) approach is employed to investigate the link between house prices and the airport traffic volumes of New Zealand’s three key regions and airports (Auckland, Canterbury/Christchurch and Wellington) from July 2004 to December 2014. The empirical findings of the study suggest that airport traffic volumes positively and significantly influence the urban house prices of New Zealand’s three major regions. [ABSTRACT FROM AUTHOR]

As air transport for leisure trips, business travel and goods shipment increased rapidly over the past several decades, the emergence of airport cities has been hypothesised. Busy commercial airports may be emerging as central transport nodes in large metropolitan areas, much as ports and rail terminals were in the past, anchoring employment servicing passengers, facilitating frequent travellers and providing a spatial focus for unrelated firms. An analysis of small-area employment data for the areas surrounding 25 major US airports and the related central cities reveals the concentration of employment within 2.5 miles of these airports to be substantial—approximately half that within 2.5 miles of the central point of the corresponding CBDs—and growing. The analysis refocuses a question about the nature of spatial differentiation within metropolitan regions supporting multiple employment nodes. [ABSTRACT FROM PUBLISHER]

Air transport systems evaluation infrastructure (IESTA) is an evaluation facility for air transport systems that is currently being developed by Onera in Toulouse, France. The project aims at building a generic simulation platform, designed to ease the integration of new or existing models in order to assess air transport concepts. The first IESTA application, Clean Airport, allows the assessment of the effects of innovative concepts with regard to air traffic noise and chemical pollution on the airports' surroundings. An effective simulation capability has been built and achieved by integrating Onera's expertise in physical modelling. This article gives an overview of the resulting model toolbox architecture, the first outputs and the validation walkthrough. [ABSTRACT FROM AUTHOR]

This research examines the impact of accessibility on the growth of employment centres in the Los Angeles region between 1990 and 2000. There is extensive empirical documentation of polycentricity—the presence of multiple concentrations of employment—in large metropolitan areas. However, there is limited understanding of the determinants of growth of employment centres. It has long been held that transport investments influence urban structure, particularly freeways and airports. Using data on 48 employment centres, the effects are tested of various measures of accessibility on centre employment growth: highway accessibility, network accessibility and two measures of labour force accessibility. Access to airports is also tested. It is found that, after controlling for centre size, density, industry mix, location within the region and spatial amenities, labour force accessibility and network accessibility are significantly related to centre growth. It is concluded that accessibility continues to play an important role in urban spatial structure. [ABSTRACT FROM PUBLISHER]

A consortium of American universities was sponsored by the Federal Aviation Administration to develop technical specifications for remote airfield lighting systems that would be used for nighttime operations by general (non-commercial) aircraft. The results from three psychophysical experiments are presented here dealing specifically with the effects of light source intensity, colour and flash frequency on both objective and subjective measures of behaviour under simulated flight conditions. Of special significance, this study showed for the first time that the unified system of photometry developed by Rea et al. (2004) to model the relative contributions of rods and cones for a given visual task could also be used to model the relative contributions of rods and cones for sequential visual tasks. [ABSTRACT FROM AUTHOR]

Making greater use of smaller airports is one way that has been proposed to increase the capacity of the National Airspace System. A major difficulty is that many small airports do not have control towers, and thus capacity is severely limited during poor visibility. The authors consider a proposed system in which airplanes self-separate, so they are able to land at higher capacities without a control tower. Before such a system is implemented, it must first be shown to be safe. Safety is a difficult metric to measure and predict because accidents are so rare. Even computer simulation can be slow because of the long time to observe accidents. One methodology that has been successful in assessing aviation safety through simulation is TOPAZ (Traffic Organizer and Perturbation AnalyZer). In this study, the authors apply the methodology to assess the safety of the proposed nontowered system. [ABSTRACT FROM AUTHOR]

Despite the recent crisis in civil aviation, most agree that air traffic growth will soon recover and rise even further. To meet the expected airport demand and improve efficiency of ground operations while maintaining safety, several new operational systems and procedures are being tested and evaluated. Rapid prototyping through modeling and simulation remains a well-suited approach to meet evaluation and assessment requirements. Likewise, simulation is increasingly part of the decision support tools used by both air and ground traffic managers and the airline industry for short-term decision making. Within this context, the French Aeronautics and Space Research Center is designing a set of modeling and simulation tools for rapid prototyping of advanced operational systems and procedures. The main goal of this initiative is to develop an open, scalable, and reusable simulation architecture, facilitating both integration of additional components and interoperability between them, to evaluate and compare several airport configurations. [ABSTRACT FROM AUTHOR]