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In the realm of prognosticating the remaining useful life (RUL) of pivotal components, such as aircraft engines, a prevalent challenge persists where the available historical life data often proves insufficient. This insufficiency engenders obstacles such as impediments in performance degradation feature extraction, inadequacies in capturing temporal relationships comprehensively, and diminished predictive accuracy. To address this issue, a 1D CNN-GRU prediction model for few-shot conditions is proposed in this paper. In pursuit of more comprehensive data feature extraction and enhanced RUL prognostication precision, the Convolutional Neural Network (CNN) is selected for its capacity to discern high-dimensional features amid the intricate dynamics of the data. Concurrently, the Gated Recurrent Unit (GRU) network is leveraged for its robust capability in extracting temporal features inherent within the data. We combine the two to construct a CNN-GRU hybrid network. Moreover, the integration of data distribution alongside correlation and monotonicity indices is employed to winnow the input of multi-sensor monitoring parameters into the CNN-GRU network. Finally, the engine RULs are predicted by the trained model. In this paper, experiments are conducted on a sub-dataset of the National Aeronautics and Space Administration (NASA) C-MAPSS multi-constraint dataset to validate the effectiveness of the method. Experimental results have demonstrated that this method has high accuracy in RUL prediction tasks, which can powerfully demonstrate its effectiveness. [ABSTRACT FROM AUTHOR]

INTRODUCTION: This paper describes the method for assigning medical diagnostic and treatment capabilities and resources to the database which assists with an updated probabilistic risk analysis (PRA) tool for exploration class medical system planning. The National Aeronautics and Space Administration has used PRA since 2011 to inform mission medical system design, but existing tools are designed only for low Earth orbit. An updated PRA tool was needed to assist with exploration class missions. METHODS: A team of medical experts with a wide range of expertise and experience, including Space Medicine, was assembled to build capability and resource tables for the new PRA tool. This team met over 8 mo and used practice guidelines, literature, and experience to build capability and resource tables (CRTs) for each condition in the new PRA tool database. RESULTS: This process led to CRTs for each condition and a total of 617 distinct capabilities and 839 discrete resources. CONCLUSION: The CRT method is an effective way to translate medical practice guidelines into capabilities and resources usable by PRA tools for exploration class medical system planning. This same method may be used in commercial space ventures and in other applications in which medical predictive analytics are informative. [ABSTRACT FROM AUTHOR]

Accurate navigation is a crucial asset for safe aviation operation. The GNSS (Global Navigation Satellite System) is set to play an always more important role in aviation but needs to cope with the risk of interference, possibly causing signal disruption and loss of navigation capability. It is crucial, therefore, to evaluate the impact of interference events on the GNSS system on board an aircraft, in order to plan countermeasures. This is currently obtained through expensive and time-consuming flight measurement campaigns. This paper shows on the other hand, a method developed to create a virtual digital twin, capable of reconstructing the entire flight scenario (including flight dynamics, actual antenna, and impact of installation on aircraft) and predicting the signal and interference reception at airborne level, with clear benefits in terms of reproducibility and easiness. Through simulations that incorporate jamming scenarios or any other interference scenarios, the effectiveness of the aircraft's satellite navigation capability in the real environment can be evaluated, providing valuable insights for informed decision-making and system enhancement. By extension, the method shown can provide the ability to predict real-life outcomes even without the need for actual flight, enabling the analysis of different antenna-aircraft configurations in a specific interference scenario. [ABSTRACT FROM AUTHOR]

This paper considers the comparative analysis of the physical and mathematical methods of the optimal operation of aviation objects' automatic control systems, which is an urgent scientific and technical task. The paper also represents the corresponding stability criteria, depending on the operating conditions, and the influence of external factors that allows ensuring the automatic control systems' reliable operation not only in normal circumstances, but also in the presence of probable disagreements. The scientific novelty of the research lies in developing new stability criteria by means of synthesising the influence of different factors and also the ability to ensure optimal functioning of the automatic control systems. Corresponding mathematical and computer models have been developed. The use of these models allows to determine the optimal stability criteria for control systems with parameters of a different physical nature and ensure reliable operation of electromechanical systems for general and special applications based on the current analysis. The research results are illustrated by corresponding mathematical models, engineering calculations and modelling of the optimal control limits depending on the influence of various factors. The simulation results coincide with the theoretical calculations, which indicates the consistency between the microprocessor-based and software of automatic control systems. [ABSTRACT FROM AUTHOR]

Aluminum alloys (AAs) are pivotal materials in modern aircraft due to their superior mechanical properties and low weight. The structural integrity of these alloys, crucial for aircraft safety, heavily depends on heat treatment processes that alter their mechanical characteristics. Nondestructive evaluation (NDE) techniques, such as eddy current (EC) conductivity measurements, play a vital role in assessing these alloys throughout their lifecycle. EC methods enable the measurement of electrical conductivity, a structure-sensitive parameter that correlates with mechanical properties affected by heat treatments and operational stresses. This paper reviews the application of EC conductivity measurements in the aerospace industry, focusing on their role in assessing AA structural integrity. It discusses how EC methods can penetrate non-conductive coatings, crucial for in-service measurements without surface removal. Recent developments include a novel small-size EC probe and signal processing algorithms aimed at enhancing sensitivity to conductivity changes through dielectric coatings, up to 0.5 mm thick, commonly found in aircraft structures. Key findings include analyses of specific electrical conductivity (SEC) changes in AAs due to heat treatment deviations and long-term operational stresses, crucial for predicting residual life and maintaining safety standards. Case studies on aircraft wing skins and helicopter rotor blades demonstrate the practical application of EC conductivity meters in identifying critical damage zones. The methodology proves effective in evaluating localized degradation based on SEC distributions, thereby enhancing maintenance efficiency and aircraft safety. Overall, this research underscores the significance of EC conductivity measurements in advancing NDE practices for AAs in aircraft applications. The methodologies and findings presented aim to improve safety, durability assessment, and maintenance efficiency in the aerospace industry. [ABSTRACT FROM AUTHOR]

This paper explores the influence of engine modernization on the dynamic stability and performance of a general aviation aircraft. Utilizing an integral mathematical model, the study conducts a comparative analysis of the I-23 Manager piston-engine aircraft and its modified I-31T turboprop version, examining changes in aircraft dynamics depending on the power plant type. The modernization necessitated a redesign of the nose section of the fuselage, resulting in alterations to the external shape and flight properties of the aircraft. The research evaluates various dynamic stability parameters, including phugoid, short period, Dutch roll, roll, and spiral modes, under different flight conditions. Results indicate minimal changes in aerodynamic characteristics due to the engine type, yet significant improvements are observed in efficiency, noise reduction, and operational costs. The impact of the propulsion unit on the dynamic stability of the light aircraft was assessed as insignificant, suggesting that the strategy of modernizing an existing piston-driven aircraft by switching to a turboprop drive is indeed promising. With appropriate initial design assumptions, a modern turbine aircraft with strong flight qualities can be efficiently modernized in this way, without compromising the good flying properties of the existing plane. The outcomes are validated against flight tests, reinforcing the viability of integrating more sustainable and efficient propulsion systems into light aircraft. This study may therefore inform future design and regulatory decisions, providing a perspective on the implications of engine upgrades in the general aviation sector. [ABSTRACT FROM AUTHOR]

The operating room is the environment where harm to the patient is most likely. Robotic surgery was listed as one of the top 10 health hazards as late as 2020. Taking inspiration from other fields of application, such as aeronautics, checklists have been increasingly implemented in medical practice over the years, becoming essential components of the operating theatre. In addition to checklists, simulation has taken on a fundamental importance in reducing errors. This paper aims to provide a narrative review to assess the importance of checklists and training in robotic surgery and how they improve the outcome. A comprehensive literature search from January 2000 to September 2023 was conducted. A total of 97 articles were included in the initial search. Eleven studies were deemed relevant and were considered eligible for full-text reading. Among these, ten studies focused on the analysis of training effectiveness. An article in our review assessed the benefits of introducing checklists in the operating room. Innovations created in aviation, such as checklists and simulation, have entered the medical field to prevent human error. Developing dedicated checklist and surgical teams, through theoretical and practical training, has become essential in modern medicine. Tools such as checklists, training, and simulation are among the best methods to reduce adverse medical events. [ABSTRACT FROM AUTHOR]

SMA actuators are a group of lightweight actuators that offer advantages over conventional technology and allow for simple and compact solutions to the increasing demand for electrical actuation. In particular, an increasing number of SMA torsional actuator applications have been published recently due to their ability to supply rotational motion under load, resulting in advantages such as module simplification and the reduction of overall product weight. This paper presents the conceptual design, operating principle, experimental characterization and working performance of torsional actuators applicable in active rudder in aeronautics. The proposed application comprises a pair of SMA torsion springs, which bi-directionally actuate the actuator by Joule heating and natural cooling. The experimental results confirm the functionality of the torsion springs actuated device and show the rotation angle of the developed active rudder was about 30° at a heating current of 5 A. After the design and experiment, one of their chief drawbacks is their relatively slow operating speed in rudder positioning, but this can be improved by control strategy and small modifications to the actuator mechanism described in this work. [ABSTRACT FROM AUTHOR]

Although the use of articulated robots and AGVs is common in many industrial sectors such as automotive or aeronautics, the use of mobile manipulators is not widespread nowadays. Even so, the majority of applications separate the navigation and manipulation tasks, avoiding simultaneous movements of the platform and arm. The capability to use mobile manipulators to perform operations on moving objects would open the door to new applications such as the riveting or screwing of parts transported by conveyor belts or AGVs. This paper presents a novel position-based visual servoing (PBVS) architecture for mobile manipulators for precise industrial operations on moving parts. The proposed architecture includes a state machine to guide the process through the different phases of the task to ensure its correct execution. The approach has been validated in an industrial environment for screw-fastening operations, obtaining promising results and metrics. [ABSTRACT FROM AUTHOR]

For over a decade, the National Aeronautics and Space Administration (NASA) has tracked and configuration-managed approximately 30 risks that affect astronaut health and performance before, during and after spaceflight. The Human System Risk Board (HSRB) at NASA Johnson Space Center is responsible for setting the official risk posture for each of the human system risks and determining—based on evaluation of the available evidence—when that risk posture changes. The ultimate purpose of tracking and researching these risks is to find ways to reduce spaceflight-induced risk to astronauts. The adverse effects of spaceflight begin at launch and continue throughout the duration of the mission, and in some cases, across the lifetime of the astronaut. Historically, research has been conducted in individual risk "silos" to characterize risk, however, astronauts are exposed to all risks simultaneously. In January of 2020, the HSRB at NASA began assessing the potential value of causal diagramming as a tool to facilitate understanding of the complex causes and effects that contribute to spaceflight-induced human system risk. Causal diagrams in the form of directed acyclic graphs (DAGs) are used to provide HSRB stakeholders with a shared mental model of the causal flow of risk. While primarily improving communication among those stakeholders, DAGs also allow a composite risk network to be created that can be tracked and configuration managed. This paper outlines the HSRB's pilot process for this effort, the lessons learned, and future goals for data-driven risk management approaches. [ABSTRACT FROM AUTHOR]

The present paper examines the use of modified dual-wavelength sawtooth serrations introduced at the trailing edge (TE) of a National Advisory Committee for Aeronautics (NACA) 65 (12)-10 airfoil as a passive means for the control of airfoil broadband noise. The studies are conducted for different parameters such as serration wavelengths (λ), serration amplitudes (h) as well as (hꞌ) modified amplitude to determine the best serration parameter which provides higher noise reductions. The reduction of noise level brought by the modified dual-wavelength sawtooth serrations at the TE is about 4 dB, while it is about 3.3 dB for the simple ones. It reveals that the modified sawtooth can provide a substantial reduction of self-noise alongside the interaction noise over an extensive range of frequencies which indicates the existence of strong far-field destructive interference (i.e., feedback) from low to mid-frequency ranges (i.e., 1.5 - 5 kHz). The TE serrated airfoils show lower acoustic emissions as compared to baseline although they exhibit a common behavior for all emission angles. The large noise decrease provided by the dual-wavelength sawtooth may be because of the significant reductions in the scattering intensity of sound as well as strong far-field destructive interference owing to the presence of two roots between the two successive maximum amplitude peaks. [ABSTRACT FROM AUTHOR]

Global navigation satellite system (GNSS) integrity monitoring (IM) has been introduced in aviation, but remains challenging for urban scenarios because of limited satellite visibility and strong multipath and non-line-of-sight effects. Consequently, factors such as limited measurement redundancy and inaccurate uncertainty modeling significantly compromise positioning and IM performance. To alleviate these issues, this paper proposes an integrity-constrained factor graph optimization model for GNSS positioning augmented by switch variables. In contrast to conventional IM methods, this method enhances redundancy through the factor graph structure. Instead of directly excluding measurements, the proposed method reweights the measurements by using switch variables to satisfy a chi-square test constraint within the optimization, ultimately yielding optimal positioning accuracy. Moreover, a proper protection level that conservatively bounds the positioning error can be derived by using the modified weighting matrix under a single-fault assumption. The effectiveness of the proposed method was verified based on data sets collected in open-sky and urban-canyon areas in Hong Kong. [ABSTRACT FROM AUTHOR]

Global navigation satellite systems have enabled significant improvements in aeronautical navigation. However, in recent years, a growing number of interference events have been reported by flight crews. In this paper, we first identify such events using crowd-sourced surveillance data collected between February and December 2022 for three different regions: the Baltic states, eastern Europe bordering the Black Sea, and the eastern Mediterranean. Then, we assess the extent and duration of these events to determine their impact on civil aviation. The analysis shows different characteristics, ranging from isolated events to regular large-scale and recurrent disruptions. Next, we identify aircraft types for the affected flights and evaluate flight plan data with respect to navigation equipment in order to identify flights that rely solely on satellite navigation and that might require assistance in the case of a loss of satellite navigation. Finally, we show the impact of radio frequency interference (RFI) on a selected passenger flight by analyzing automatic dependent surveillance-broadcast data as well as avionics data obtained from the airline's flight data monitoring department for that specific flight and link the observations to the warnings triggered by the aircraft to alert the flight crew while encountering RFI. [ABSTRACT FROM AUTHOR]

The development of aviation market in Southeast Asia after the Covid-19 pandemic is promising. More aircraft are delivered to the Asia-Pacific region, including the Association of South East Asian Nations (ASEAN) Member States. The introduction of ASEAN Open Skies (also known as ASEAN Single Aviation Market) a decade earlier together with ASEAN Economic Community Blueprint 2025 goals for an integrated and cohesive regional economy highlight the importance of a seamless air connectivity. Liberalisation of the airline industry in ASEAN Member States is crucial to restart the airline industry prepandemic and to grasp the so-called Asian century momentum. However, ASEAN Member States are reluctant towards liberalisation efforts, maintaining protectionism on both freedoms of the air (traffic rights) as well as foreign direct investment (ownership and control). Existing legal framework at regional level, namely ASEAN Framework Agreement on Services (AFAS) and ASEAN Trade in Services Agreement (ATISA), only received lukewarm attention from ASEAN Member States. This article discusses the urgency to recall the commitment of a gradual liberalisation based on AFAS and ATISA among the ASEAN Member States, the implementation of which will lead to the establishment of a regional community carrier which benefits ASEAN citizens. [ABSTRACT FROM AUTHOR]

This paper investigated the discomfort caused by vertical whole-body vibration (WBV) over 20 minutes using data recorded at the front, middle, and rear seats of the passenger cabin in civil aviation during a cruising flight. Twenty-four subjects experienced each stimulus at 0.5 ms−2 r.m.s. and judged discomfort at various moments (i.e. 1/6, 5, 10, 15, and 20 min) using a category-ratio method. The difference in discomfort due to high-frequency vibration components vanished after 10 min. Based on Stevens' power law, a method is developed to estimate long-term vertical WBV discomfort by considering the static discomfort and an interaction coefficient between vibration and static discomfort as parameters. The proposed estimation method showed high accuracy with determination coefficients (R2) higher than 0.97 and good linearity with values of growth rates 0.95, 1, and 0.95 for the vertical WBV discomfort at the front, middle, and rear seat positions in the aircraft cabin. Practitioner summary: An estimation method for the discomfort caused by vertical WBV considering the duration and static sitting discomfort is developed. This method can provide accurate discomfort estimating for long-term vibration exposure, e.g. in civil aviation during a cruising flight, by introducing an 'interaction term' between static and dynamic discomfort. [ABSTRACT FROM AUTHOR]

In order to study the blast damage effects of aviation kerosene storage tanks, the out-field explosion experiments of 8 m3 fixed-roof tanks were carried out. The fragments, shock wave and fireball thermal radiation of the tank in the presence of bottom oil, half oil and full oil, as well as empty tank, were investigated under internal explosion by various TNT charge contents (1.8 kg, 3.5 kg and 6.2 kg). The results showed that the tank roof was the only fragment produced, and the damage forms could be divided into three types. The increase of TNT charge content and oil volume enlarged the deformation of the tank, while the hole ratio presented a trend of increase first and then decrease. The Hr, max and Vmax values positively increased as increasing the TNT charge content and oil volume (from empty to half oil), but decreased in full oil. The Pmax values had a progressive increase with the increment of TNT charge content, but not the case with the increase in oil volumes. The development of fireball was divided into three stages: tank roof 'towed' flame, jet flow flame tumbling and rising, and jet flow flame extinguishing. The Dmax and Hf, max values both increased as increasing TNT charge content and oil volumes. The oscillation phenomenon of fireball temperature was observed in the cooling process. The average temperature of fireball surface was positively correlated with TNT charge content, and negatively correlated with oil volumes. [ABSTRACT FROM AUTHOR]

With the process of urbanization and the increase in car ownership, traffic problems are becoming increasingly prominent. In order to improve traffic mobility and improve traffic safety, a machine learning based autonomous obstacle avoidance system was studied and designed in the context of intelligent transportation. Design an obstacle avoidance hardware system consisting of a tracking sensor module, an intelligent patrol module, an obstacle avoidance sensor module, and a motor module. Through the coordination and cooperation of multiple modules, the adaptive ability of the obstacle avoidance system is improved. On the basis of hardware design, a road coordinate system is established, and the lane‐changing path is planned with the longitudinal, lateral distance and speed of the ego vehicle and the preceding vehicle as input, and the vehicle steering and lane‐changing control is completed using the front wheel angle of the ego vehicle as the control quantity. The model predictive control method is used for obstacle avoidance trajectory planning. Based on the obstacle avoidance path planning results, the reinforcement learning method is used to design the vehicle's autonomous obstacle avoidance early warning to improve the efficiency of obstacle avoidance. The experimental results show that the designed system can maintain the lateral stability of the vehicle under continuous steering conditions, and the fit between the path tracking and the reference path is better, that is, the vehicle obstacle avoidance control effect is better; the convergence speed is faster. The vehicle autonomous obstacle avoidance warning time is short, which can ensure the safety of the vehicle to the greatest extent. This research achievement will provide important support for the development and practical application of intelligent transportation systems, and promote innovation and progress in the transportation field. [ABSTRACT FROM AUTHOR]

In this research, a hot composting experiment was carried out with a mixture of three waste fractions; guts 50%, manure 30% and dead leaves 20%. The experiment showed that the resulting compost has a high-level organic substance content and a minor salt content that can be a healthy soil amendment. However, the experiment did not evaluate the compost mass evolution during 45 days of the mechanism. The main aim of this work tried to improve the performance of valorization by reducing the duration of composting, evaluating its economic efficiency (monitoring of mass), and improving the qualitative efficiency. To this effect, the feasibility study aimed to rapidly compost a mixture of 50% underground guts waste and 50% manure over a period of 23 days. The results proved that the C/N rate and electrical conductivity of the compost obtained is above the limits requested by most standards. Moreover, the temperature recorded of the heap did not exceeded 39.53°C at any day of composting. Nevertheless, the economic efficiency reached 47.9%. [ABSTRACT FROM AUTHOR]

The Vacuum-Assisted Resin Transfer Molding (VARTM) process has gained popularity as a reliable and cost-effective alternative to autoclave molding for high-performance composite production, which is especially interesting for aeronautics, where weight reduction is crucial. However, to date, the environmental impact of components produced through VARTM remains relatively unknown. To address this gap, this study applied the Life Cycle Assessment (LCA) methodology to estimate the environmental impact of a thermoset composite laminate produced through heated VARTM. Aiming to support the decision, the VARTM composite part's production was compared to conventional autoclave manufacturing, and the influence of alternative end-of-life (EoL) scenarios and energy mixes was considered, through LCA. The study found that energy consumption represented the majority of the environmental impacts of the heated VARTM component (33%), followed by carbon fibers, resins, consumables, and wastes. In terms of the comparative analysis, the autoclave manufacturing process showed better environmental results. Regarding EoL management, supercritical hydrolysis (with heat recovery) recycling emerges as the most beneficial method, reducing the impacts of the VARTM-manufactured component by 25%. This study emphasizes the importance of sustainable practices, such as reducing energy consumption, using low-carbon energy mixes, and adopting recycling methods to improve VARTM composite's environmental performance. [ABSTRACT FROM AUTHOR]

In this manuscript, we present a novel deployment protection method aimed at safeguarding aeronautical radio altimeters (RAs) from interference caused by fifth-generation (5G) telecommunication base stations (BSs). Our methodology involves an integrated interference model for defining prohibited zones and utilizes power control and angle shutoff methods to mitigate interference. First, to ensure reliable protection, we define both horizontal and vertical prohibited zones and investigate their variations to immunize RA against 5G interference. Second, we validate the effectiveness of the model in various operational scenarios, analyzing the influence of factors such as base station types, antenna parameters, flight altitude, and aircraft attitudes to cover a wide range of real-world scenarios. Third, to mitigate interference, we propose and analyze the power control and angle shutoff methods through simulation for the RMa prohibited zone. Our results demonstrate the efficacy of the deployment protection method in safeguarding RAs from 5G interference, providing guidance for interference protection during civil aviation operations and base station deployment near airports. [ABSTRACT FROM AUTHOR]

Various industrial sectors require highly specialized and efficient materials for applications in fields such as the military, aeronautics, aerospace, and mechanical and civil engineering. Composite materials that meet the stringent requirements across these domains have become prominent, often serving as structural components and requiring precise mathematical modeling. Zigzag (ZZ) and Layerwise (LW) theories are commonly used for laminated-beam structural analysis. Although the LW theory provides superior accuracy, it suffers from an increase in unknowns as the number of layers grows. Conversely, the ZZ theory is less computationally intensive and less accurate. This study proposes an exponential high-order zigzag function with a unified kinematic formulation to enhance the accuracy of the ZZ theory. The results were compared with those of existing models and demonstrated excellent agreement with the reference solutions, irrespective of the layer count or slenderness index, making it a more efficient choice for laminated-beam analysis. [ABSTRACT FROM AUTHOR]