Ground Transportation Research Articles

Wasserstein Robust Classification with Fairness Constraints

Problem definition: Data analytics models and machine learning algorithms are increasingly deployed to support consequential decision-making processes, from deciding which applicants will receive job offers and loans to university enrollments and medical interventions. However, recent studies show these models may unintentionally amplify human bias and yield significant unfavorable decisions to specific groups. Methodology/results: We propose a distributionally robust classification model with a fairness constraint that encourages the classifier to be fair in the equality of opportunity criterion. We use a type-[Formula: see text] Wasserstein ambiguity set centered at the empirical distribution to represent distributional uncertainty and derive a conservative reformulation for the worst-case equal opportunity unfairness measure. We show that the model is equivalent to a mixed binary conic optimization problem, which standard off-the-shelf solvers can solve. We propose a convex, hinge-loss-based model for large problem instances whose reformulation does not incur binary variables to improve scalability. Moreover, we also consider the distributionally robust learning problem with a generic ground transportation cost to hedge against the label and sensitive attribute uncertainties. We numerically examine the performance of our proposed models on five real-world data sets related to individual analysis. Compared with the state-of-the-art methods, our proposed approaches significantly improve fairness with negligible loss of predictive accuracy in the testing data set. Managerial implications: Our paper raises awareness that bias may arise when predictive models are used in service and operations. It generally comes from human bias, for example, imbalanced data collection or low sample sizes, and is further amplified by algorithms. Incorporating fairness constraints and the distributionally robust optimization (DRO) scheme is a powerful way to alleviate algorithmic biases. Funding: This work was supported by the National Science Foundation [Grants 2342505 and 2343869] and the Chinese University of Hong Kong [Grant 4055191]. Supplemental Material: The online appendices are available at https://doi.org/10.1287/msom.2022.0230 .

Scalable Combinatorial Vertiport Placement Method for an Urban Air Mobility Commuting Service

Vertiport locations have a significant impact on the time savings provided by an urban air mobility (UAM) commuting service relative to ground transportation and, thereby, greatly affect the value proposition and demand for UAM commuting services. In this paper, we present a discrete combinatorial vertiport placement method with a flexible objective function capable of directly optimizing for commuting demand. Preprocessing and postprocessing formulations that effectively reduce problem size and increase solution quality are also described. Demand-maximizing vertiport placement results are provided for Atlanta, New York City, San Francisco, and Seattle. We also present results showing the sensitivity of potential commuting demand to number of vertiports, ticket price, and service delay. Additionally, results that illustrate the impact of limiting vertiport placement to locations with existing airport and helipad infrastructure are presented. Finally, vertiport placement results optimized using a capacitated profitability-maximization objective are outlined.

Unlocking the power of energy efficiency: A multi-benefit approach with the referee tool

Unlocking the power of energy efficiency: A multi-benefit approach with the referee tool Energy efficiency is a cornerstone of the European Green Deal and the European Union’s (EU) pathway toward carbon neutrality. With implementation efforts underway across the Continent, the Referee tool stands ready to support decision-makers and stakeholders in their energy efficiency planning, embracing a multi-benefits approach. Energy efficiency has long been championed as a vital tool in the fight against climate change. According to the 2022 IPCC report, energy efficiency in the industrial, ground transportation, and building sectors is the best way to reduce greenhouse gas emissions. For instance, significant energy efficiency improvements in the building sector (e.g. more energy-efficient heating systems, better insulation) could reduce the energy demand of the residential building stock in the EU by 19.4% in 2030 and by 43% in 2050 compared to 2018 levels.

Implementation and Management of a Flight Program.

Air medical transport of critically ill and injured patients began during World War II. Now air transport has become an integral part of health care, nationally and internationally. With the development of portable medical equipment critical care has extended beyond the hospital by bringing critical care to the scene or to rural hospitals. Air medical programs transport critically ill and injured patients by helicopter or airplane while continuously providing critical care enroute. These transports are interfacility from accident scenes, disaster areas, and remote locations where the patient is transported to a tertiary care center so that definitive care will be provided. The 2 modes of air transport are rotor wing (helicopters) and fixed wing (airplanes). Air medical transport is utilized when ground transportation is not conducive to patient criticality or location relative to a tertiary care center. There are many factors to consider when choosing a mode of transport, and each mode has its own unique advantages and disadvantages. Air medical programs place emphasis on clinical care, safety, and quality assurance, with the patient being the focused beneficiary. This article addresses implementation and management of rotor wing air medical transport with a focus on standards of care, safety, and quality.

Перспективы применения дисперсно-наполненных композитов при полевом ремонте корпусных деталей наземных транспортно-технологических средств (обзор)

The main damages of body parts of ground transportation and technological facilities that occur during operation are presented. The main methods of repair of body parts, their advantages and disadvantages are considered. It is shown that repairs using polymer composite materials can be carried out not only within the framework of a repair enterprise, but also in the field.

Influence of inflow conditions on simplified heavy vehicle wake

In the current study, the impact of various inflow conditions, including turbulent wind profiles and turbulent intensity, on the wake flow topology of a simplified ground transportation system (GTS) model was investigated using the improved delayed detached eddy simulation. The reliability and accuracy of the numerical method adopted in this paper were verified against the results comprising the aerodynamic drag and the wake flow structure of the GTS model obtained from the large eddy simulation and the experimental data. The research results indicate that turbulent winds characterized by logarithmic and uniform velocity profiles resulted in significantly different wake flow topologies yet exhibit the same dominant frequency. The turbulent intensity also plays a crucial role in the wake of the GTS model. It is observed that an increase in turbulence intensity corresponds with a rise in the aerodynamic drag. Specifically, when the turbulence intensity is set at 15%, there is a 3.68% increase in the aerodynamic drag of the GTS model compared to a case where the turbulence intensity was only 5%. In addition, the turbulent intensity is critical to the dominant frequency characteristics of the wake region of the GTS model. These results demonstrate that both the velocity profiles and the turbulence intensities significantly influence the wake flow topology and aerodynamic drag of the GTS model, providing a valuable reference for establishing appropriate inflow conditions and exploring the formation mechanism of flow topology in the wake of the GTS model.

Stronger family ties vs. less social contact: Use intention of autonomous vehicles in family tourism

Autonomous vehicle-related services, such as Waymo, are now available for tourists, creating a new era of ground transportation in the tourism industry. However, research on autonomous vehicles in tourism literature remains in the beginning stage. To enrich understanding of autonomous vehicles in tourism and to contribute practical insights, this study examines potential users’ assessment, expectancy, and use intention toward autonomous vehicles in family tourism. A total of 439 complete survey responses were collected from car owners in Japan. Results confirmed perceived benefit, effort expectancy, and perceived risk as significant antecedents of both positive (i.e. family ties enhanced by autonomous vehicles) and negative expectancy (i.e. reduced social contact through autonomous vehicles), which influenced use intention toward autonomous vehicles. Additionally, females, those of higher age demographics (50s–60s), and those with larger family sizes (three or more) were more concerned with reduced social contact when evaluating their use intention toward autonomous vehicles.

Quantifying energy flexibility potential of ground electric vehicles in an airport with real behavior data

Towards sustainable airports, vehicle electrification can not only reduce direct carbon emissions, but also provide great energy flexibility to integrate renewable energy. However, it remains challenging to quantify their potential, due to a lack of understanding of various vehicles’ complicated behavior in an airport. Hereby, a large-scale investigation into the behavior and energy consumption of all types of vehicles was performed in a Chinese hub airport. From the overall perspective of an airport, a behavior data-based simulation was conducted to evaluate their accessible storage (EAS) under different conditions, including charging infrastructure and flight schedule. For the full-potential case with a normal flight schedule, the airside vehicles have the largest share of EAS (60 %), followed by the landside vehicles in the ground transportation center (30 %) and the staff parking lots (10 %). The overall EAS is almost as large as the energy storage demand to realize a fully solar-supplied airport. Nevertheless, the current capacity is limited to only 15 % of the full potential by electrification rate and charging behavior. This study fills the gap of lacking behavior data of the vehicles in airports. The findings shed light on the role of vehicle electrification in airport decarbonization and provide guidelines for future practice.

Mitigating low-frequency broadband aircraft noise through a structured assembly of acoustic material and devices

Addressing the challenge of attenuating low-frequency broadband noise emerges as a critical concern within the fields of aeronautics, ground transportation, and construction industries, requires innovative solutions for enhanced acoustic control. Over the last few decades, the literature has seen an increase in low-frequency noise control solutions centered around acoustic metamaterial designs. These proposed technologies exhibit promising acoustic performance, especially proving superior to conventional sound insulation materials in constrained spaces, such as in aerospace applications. Despite the efficacy of typical metamaterials in attenuating tonal noise through narrow resonant frequency maxima, practical applications reveal some challenges, as even slight variations in tonal noise frequencies can compromise the overall effectiveness of such solutions. In response to this, the present paper introduces a novel thin acoustic metamaterial design aimed at improving broadband noise attenuation at low frequencies. This design uses carefully arranged structured metamaterials within a fiberglass layer to create optimal resonance frequency bands for maximum low-frequency noise attenuation. Performance assessment in the low-frequency domain employed COMSOL Multiphysics finite element methods, predicting sound absorption coefficient and transmission loss. Results confirm the effectiveness of the proposed metamaterial design, showcasing broad noise attenuation at low frequencies.

A BI-OBJECTIVE COST MINIMIZATION MODEL FOR THE INSULAR TOUR ROUTE PLANNING PROBLEM

This article presents a study on the development of a bi-objective cost problem optimization model in planning tourist routes in the island zone. This problem is a new variant of the tour route plan problem. Bi-objective view of two cost components, namely maritime transportation costs and ground transportation costs. Two models were formulated using a mixed integer linear programming approach. The first model was designed to minimize one of the two cost components separately. The second model was bi-objective cost minimization based on the priority weights of the two costs. It was designed to determine minimum transportation costs based on priority weights. Model testing was carried out through numerical experiments on several cases that often occur in industries in Maluku, Indonesia, especially tourism and goods shipping. Each case has variations in the number of islands and nodes. As a result, the model can demonstrate its adaptability to changes in objectives and parameters. For cases that do not have a single solution, an increase in the network structure on the number of islands and nodes will increase the variety of efficient alternative solutions. The set of efficient solutions also shows an inverse relationship between MTC and GTC. The results also show that MTC minimization cannot be used as a reference for TC minimization in cases with many nodes and islands. Efforts to minimize MTC in the island zone impact reducing total costs but do not mean minimizing total costs. In addition, based on the exponential trend line of computing time, the number of nodes has a more significant influence on computing time compared to the number of islands.

Impacts of the COVID-19 pandemic on population management in AZA.

Soon after the onset of the COVID-19 pandemic, almost all Association of Zoos and Aquariums (AZA) facilities closed to the public. Resulting cost-saving and safety measures led some facilities to temporarily cease or reduce animal breeding and/or transfers. We surveyed AZA facilities and Species Survival Plan® (SSP) Coordinators for AZA's cooperative population management programs to evaluate how widespread these decisions were, if impacts varied by taxa, and how the AZA community navigated related challenges during the pandemic. We found that 60% of responding facilities did not suspend breeding and 22% did not suspend transfers. About 50% of responding zoos increased their reliance on ground transportation to move animals, while aquariums reported no change to transportation methods. SSP Coordinators reported the main reason why breeding decreased, regardless of taxa, was due to canceled or delayed transfers. The reasons transfers decreased differed by taxa, such as limited financial resources and lack of access to air transportation. The majority of respondents for both surveys stated transfers were the greatest challenge they faced. To address this, facilities utilized alternative transportation methods and worked closely with nearby zoos and aquariums for the movement of animals, while SSP Coordinators issued alternative transfer recommendations. If another pandemic or other widespread facility closure occurs, our research highlights the importance of communication, collaboration, and flexibility to fulfill breeding and transfer recommendations to maintain sustainable zoo and aquarium populations.

Abstract WP22: “Chopperlysis:” Improved Functional Outcomes Associated With Helicopter Transport in Large Vessel Occlusion Stroke Patients Treated With Tenecteplase

Introduction: Tenecteplase (TNK) is increasingly being utilized for IV thrombolysis in acute ischemic stroke, including for patients with large vessel occlusion (LVO) prior to transfer to an endovascular thrombectomy (EVT) capable center (TCC). However, there is limited data regarding factors that influence functional outcome between the time of TNK administration and TCC arrival. The purpose of this analysis is to characterize the effect of the arrival method on the effectiveness of TNK to improve patient outcomes. Methods: A retrospective registry of stroke patients between 2019-2023 at a single comprehensive stroke center was queried. Patients with LVO stroke who had complete data for method of arrival (i.e. ground transportation versus helicopter), TNK treatment, and available 90-day modified Rankin score (mRS) were included. The primary outcome was a favorable 90-day mRS of 0-2. Categorical variables were reported as frequencies, and associations across variables were analyzed using Chi-square test or Fisher's exact test. Odds ratios were calculated with univariate logistic regressions. Results: Of 2675 patients meeting inclusion criteria, 14.4% arrived by helicopter and 85.6% arrived by ground transportation. 174 (6.5%) were treated with TNK, including 5.1% of ground transported patients and 14.1% of air transported patients. Irrespective of EVT, patients arriving by ground did not differ in likelihood of achieving the primary outcome whether they did or did not receive TNK (53.9% TNK vs. 48.4% no TNK, p=0.35). However, patients arriving by helicopter had a significantly higher likelihood of achieving the primary outcome with TNK, regardless of EVT (60% TNK vs. 41.2% no TNK, p=0.04), and in patients transported by helicopter who did not undergo EVT, there was an even higher likelihood of good functional outcome associated with TNK treatment (69.2% TNK vs. 40.1% no TNK, p=0.049). Conclusion: In our cohort, treatment with TNK was associated with improved functional outcomes in helicopter transported patients but not in those transported by ground, and this benefit was found to be even more robust in patients who did not undergo EVT. Future studies are needed to validate these findings and investigate the underlying pathophysiological mechanism.

Sustainable Ground Transportation and the E-Commerce Revolution: Innovations and Challenges at the Intersection

This review paper offers a comprehensive exploration of the symbiotic relationship between sustainable ground transportation and the dynamic realm of e-commerce. It delves into the critical intersection of environmental sustainability, technological innovation, and the evolving landscape of online commerce. This review synthesises cutting-edge technologies and strategies aimed at reducing energy requirements and environmental impacts in ground transportation. It explores advancements in lightweight materials, aerodynamics, and alternative fuels, emphasising their potential to mitigate the environmental footprint of vehicles. Additionally, the transition towards zero-emission vehicles, including battery-operated and fuel-cell vehicles, is analysed, taking into account both short-term and long-term outlooks. Simultaneously, the paper delves into the evolving landscape of e-commerce, which has become an integral part of modern consumer behaviour. It investigates the influence of e-commerce on ground transportation practices, emphasising the importance of efficient logistics, last-mile delivery, and sustainability in meeting the demands of the digital commerce era. By providing a holistic view of the challenges and opportunities at the nexus of sustainable ground transportation and e-commerce, this review paper offers valuable insights for researchers, policymakers, and industry stakeholders striving to shape a more sustainable and responsive future for ground transportation in the digital age.

A hybrid strategy using an ambulance and a helicopter to convey thrombectomy candidates to definite care: a prospective observational study

BackgroundMechanical thrombectomy is the treatment of choice for large vessel occlusion strokes done only in comprehensive stroke centres (CSC). We investigated whether the transportation time of thrombectomy candidates from another hospital district could be reduced by using an ambulance and a helicopter and how this affected their recovery.MethodsWe prospectively gathered the time points of thrombectomy candidates referred to the Tampere University Hospital from the hospital district of Southern Ostrobothnia. Primary and secondary transports were included. In Hybrid transport, the helicopter emergency medical services (HEMS) unit flew from an airport near the CSC to meet the patient during transport and continued the transport to definitive care. Ground transport was chosen only when the weather prevented flying, or the HEMS crew was occupied in another emergency. We contacted the patients treated with mechanical thrombectomy 90 days after the intervention and rated their recovery with the modified Rankin Scale (mRS). Favourable recovery was considered mRS 0–2.ResultsDuring the study, 72 patients were referred to the CSC, 71% of which were first diagnosed at the PSC. Hybrid transport (n = 34) decreased the median time from the start of transport from the PSC to the computed tomography (CT) at the CSC when compared to Ground (n = 17) transport (84 min, IQR 82–86 min vs. 109 min, IQR 104–116 min, p < 0.001). The transport times straight from the scene to CT at the CSC were equal: median 93 min (IQR 80–102 min) in the Hybrid group (n = 11) and 97 min (IQR 91–108 min) in the Ground group (n = 10, p = 0.28). The percentages of favourable recovery were 74% and 50% in the Hybrid and Ground transport groups (p = 0.38) from the PSC. Compared to Ground transportation from the scene, Hybrid transportation had less effect on the positive recovery percentages of 60% and 50% (p = 1.00), respectively.ConclusionAdding a HEMS unit to transporting a thrombectomy candidate from a PSC to CSC decreases the transport time compared to ambulance use only. This study showed minimal difference in the recovery after thrombectomy between Hybrid and Ground transports.

Comparative Analysis of Aviation and Ground Transportation Safety Standards Applicable to the Integration of Unmanned Aircraft Operations

Comparative Analysis of Aviation and Ground Transportation Safety Standards Applicable to the Integration of Unmanned Aircraft Operations

Lay-out of air source heat pump heating system in Lugang Logistics Park

In order to understand the process of using the heat pump heat organization, the author proposes to conduct a study based on the concept of heat pump air heating system in ?Land Port Logistics Park?. The author first analyzed the heating characteristics of the ground transportation fleet according to the actual situation, optimized the design of the heat pump, and proposed the same plan. Second, taking some provincial underground parks as examples, the actual performance of the park?s air source heat pump heating system was tested. According to the test, the temperature difference between the supply and return water is 3-4?C, and the average COP of the entire heating season is only 2.1. Based on the analysis and analysis, the meaning of the problem in the actual operation of the heat pump is explained, the cause of the problem is the determination of the pressure and the design plan. After installation, energy consumption can be further reduced, and it advises on the progress and use of the ventilation system. By using electric equipment to heat the docks in the port, it is possible to meet the heating needs of the park and reduce energy consumption and air pollution. Good this is a green and low carbon promise.

Мониторинг загрязнения почвенного покрова нефтепродуктами и разработка способа его рекультивации

Introduction. Oil waste has a high degree of toxicity and poses a great danger to humans and to the natural environment as a whole. One of the most acute problems is the negative impact of oily waste. The negative impact of petroleum products on the soil can lead to irreversible changes in the chemical composition, physical biochemical and microbiological properties of the soil, which determine, among other things, its fertility. The main potential sources of soil pollution with oil and petroleum products include ground vehicles, oil storage facilities, oil refining enterprises, as well as transport transporting petroleum products. The study of the physico-chemical properties of ash and slag waste to reduce the anthropogenic load on the environment. In Kazakhstan, as a result of the production activities of a number of large oil-producing enterprises, huge amounts of oil-and-oil soils have accumulated, significantly polluting the environment. The areas of polluted lands continue to increase as a result of emergency oil spills. Therefore, on the territory of the Kumkol oil field, it is very relevant to conduct environmental monitoring of soil pollution and carry out reclamation measures to restore land fertility The purpose of the research. Environmental monitoring in the conditions of development of the Kumkol deposit and the development of an effective technology for the reclamation of contaminated lands through the use of highly effective biological products to reduce the anthropogenic load on the natural environment. Research materials. For the research, samples of smeared soils of various sites of the Kumkol deposit of the Kyzylorda region of Kazakhstan were used. Research methods. The choice of soil monitoring methods was carried out taking into account the available sources of pollution and types of soil pollution: chemical, biochemical, biochemical, microbiological, etc. The analysis of existing methods of ecological monitoring of soils shows that due to the high cost and technological complexity, the use of a number of them is limited. Therefore, an effective approach to determine the degree of contamination of soils with petroleum products is the use of bioindication and biotesting methods Research results and discussion. As a result of the environmental monitoring, the technology of recultivation of polluted lands was developed using a biological product obtained by composting rice husks with the help of aerobic and anaerobic soil microorganisms. The scientific novelty of the proposed method of recultivation of contaminated soils is confirmed by the patent of the Republic of Kazakhstan, which confirms the scientific and practical significance of the work. The results of the research can be useful in the reclamation of oil-contaminated lands in other regions and the restoration of their vegetation cover. Conclusion. The monitoring of soil pollution by oil and petroleum products shows that the main potential sources include ground transportation facilities, oil storage facilities, oil refineries and transport, which first brings petroleum products. The developed technology of biorecultivation, firstly, reduces the anthropogenic load on the soil surface due to the biodegradation of oil spills, and, secondly, at the same time, the disposal of spilled oil in the form of vermicompost is carried out. In the work, for the first time on the basis of the application of a new technology for the reclamation of contaminated land resources using a biological product obtained from waste of plant and food origin, a new approach to the problem of utilization of oil-contaminated soils and restoration of their fertility, with the production of vermicompost, is proposed. Suggestions for practical application. A new approach to the problem of utilization of oil-contaminated soils and restoration of their fertility, with the production of vermicompost, is proposed, which can be useful in solving environmental problems in other oil-producing regions of Kazakhstan.

Node location of bi-level urban metro-based ground-underground logistics distribution

Metro-based underground logistics (M-ULS) can relieve the pressure of urban traffic and avert the road congestion through coordinating with ground logistics system. A bi-level node location model is proposed based on the ground-underground logistics distribution mode. The cost of delivery and pickup from the perspective of service companies and customers are minimized as the upper and lower objectives. Since the model is belonged to NP-hard problem, the simulated annealing algorithm (SA algorithm) whose new solution generation part was improved according to the characteristics of the model is used to solve the problem. In the case analysis part, the distribution nodes and customer points close to Nanjing Metro Line 3 were selected to verify the validity of the model and algorithm. The result shows that the improved SA algorithm outperformed in taking less iteration times and obtaining better solutions. The total transportation cost of the system can be reduced by 21.7 % with the optimized node location plan, and 63.6 % of the ground transportation distance can be replaced by the underground transportation, such results are also obtained when the cargo demand increases by 1.5 times and 2 times, which verifies the advantages of M-ULS node location in reducing truck emission and total delivery cost.

Study on Aerodynamic Drag Reduction by Plasma Jets for 600 km/h Vacuum Tube Train Sets

In order to break through the speed bottleneck, researchers envision using tubes to cover high-speed maglev trains and extract some of the air inside the tubes, creating a low-density environment on the ground, greatly reducing the aerodynamic drag of the trains, and in a relatively economical and feasible way, making high subsonic (600 km/h and above) and even supersonic ground transportation possible. The faster the running speed of high-speed trains, the greater the impact of aerodynamic drag on their energy consumption. Studying the aerodynamic characteristics of trains with a speed of 600 km/h can help optimize the aerodynamic shape of the train, reduce aerodynamic drag, and reduce energy consumption. This has positive implications for improving train energy efficiency, reducing energy consumption, and environmental impact. This paper adopts the numerical simulation method to study the drag reduction effect of the plasma arrangement and different excitation speeds on the train set in four positions when the incoming wind speed is 600 km/h, to analyze the mechanism of drag reduction, and then to analyze the combination of working conditions in order to investigate the drag reduction effect of plasma on the vacuum tube train set with an ambient pressure of 10,000 Pa. The findings demonstrate that the plasma induces the directional flow of the gas close to the wall to move the flow separation point backward and delay the separation of the flow, thereby reducing the front and rear differential pressure drag of the train set and lowering the aerodynamic drag coefficient of the entire train. The plasma arrangement is located at the rear of the flow separation point and in close proximity to the flow separation point. The pneumatic drag reduction effect peaks when the excitation speed reaches 0.2 times the train speed and the pneumatic drag reduction ratio is around 0.88%; the pneumatic drag reduction ratio of the rear car peaks when the excitation speed reaches 0.25 times the train speed and the pneumatic drag reduction ratio is 1.62%. The SDBD (Surface Dielectric Barrier Discharge) device is installed at the flow separation point around the nose tip of the rear car.

Vertiport Selection in Hybrid Air–Ground Transportation Networks via Mathematical Programs With Equilibrium Constraints

Urban air mobility is a concept that promotes aerial modes of transport in urban areas. In these areas, the location and capacity of the vertiports–where the travelers embark and disembark the aircraft–not only affect flight delays, but can also aggravate the congestion of ground vehicles by creating extra ground travel demands. We introduce a mathematical model for selecting the location and capacity of the vertiports that minimizes traffic congestion in hybrid air-ground transportation networks. Our model is based on a mathematical program with bilinear equilibrium constraints. Furthermore, we show how to compute a global optimal solution to this mathematical program by solving a mixed integer linear program. We demonstrate our results via the Anaheim transportation network model, which contains more than 400 nodes and 900 links.