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ABSTRACT This article proposes a new approach to implement a quality management system’s strategic structure that incorporates prospective scenarios analysis in the determination of strategic elements, such as quality policy, mission, vision, needs, and objectives. The qualitative analysis of managers’ statements about how the results were perceived revealed a significant change in strategic structure of a study case organization within the Department of Science and Aerospace Technology. This main result of this approach lies in the reorientation of managerial focus, prioritizing organizational needs management. This realignment culminates in superior results, obtained through effective actions aimed at fully satisfying these needs, thus marking a break with historical management practices.

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ABSTRACT This review article provides a concise view of the transformative role played by silicon carbide (SiC) semiconductors in the electric power industry, along with a description of their emerging applications in electric vehicles (EVs), renewable energy systems, aeronautics, and space. It highlights SiC chips’ ability to operate at high temperatures and frequencies, surpassing the limitations of traditional silicon chips and resulting in enhanced efficiency. Additionally, it also presents the capabilities of SiC devices to manage elevated power levels within reduced size and weight parameters, emphasizing their impact on augmenting power density in EVs and enhancing reliability and efficiency in renewable energy, aeronautics, and space applications. Finally, the review concludes by providing an overview of the prevailing trends, existing challenges, and the future trajectory of SiC semiconductors within these important sectors.

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ABSTRACT The research relevance is predefined by the air travel number growth. Accordingly, the relevance of this issue is increasing, especially concerning air travel safety. Also, due to the increasing demand for international flights, it becomes essential to harmonize the standards and methodology of training aviation personnel. The research aims to consider the parameters of flight safety and the impact of the unification of training programs for aviation personnel. The conclusion that unification can significantly affect safety was made with the help of scientific and special methods, including analysis, synthesis, concretization, and generalization. An analysis of existing unification methods was conducted. The multi-crew pilot training program proved to be one of the most advanced compared to standard flight crew training programs. The method was determined to be a specialized training program tailored to the needs of the aviation industry and focused on training pilots for multi-crew and jet operations. The program is more challenging, intensive and dynamic, and includes a significant amount of simulator training. Traditional flight training programs, such as Private Pilot Licenses (PPL), Commercial Pilot Licenses (CPL), instrument qualification, and multi-engine rating, have a broader scope and provide pilots with more career opportunities. Simulator training has been identified as a critical component of many flight training programs and plays a vital role in flight safety. The study may be of interest to a range of readers concerned with the issue of standardizing aviation training and improving safety in aviation, including researchers, faculty, and students of higher education institutions in the aviation field.

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ABSTRACT Polymers based on glycidyl azide polymer (GAP) and isocyanate present molecular structures dependent on NCO/OH molar ratio and diisocyanate reactivity. In this study, GAP polymers are obtained from a reaction with aromatic (toluene diisocyanate, TDI) or aliphatic (isophoranediisocyanate, IPDI) diisocyanates, varying the NCO/OH molar ratio from equimolar to 2.5. The increment in NCO/OH molar ratio increases the gel fraction in GAP/TDI polymers up to 90 wt%, along with a progressive growth in their glass transition temperature (Tg), which rises 10 °C from NCO/OH equimolar to 2.5. In opposition, in the GAP/IPDI polymers, the maximum gel fraction is 20 wt%, and the Tg value practically does not change in NCO excess. Infrared spectroscopy shows the predominant presence of urethane groups in polymers containing up to 2.0 NCO/OH molar ratio; however, at 2.5, urethane and allophanate characteristic bands are present in both polymers. That reactivity is controlled by chemical kinetics since the activation barrier of the reaction between the GAP and TDI is 10 kcal.mol-1 lower than in the corresponding reaction with the IPDI. This difference results from the sum of the higher hyperconjugative interactions, approximately 65%, and the lower steric hindrance, about 35%, in the activated complex containing the TDI.

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ABSTRACT India and Indonesia propose a bilateral cooperation to develop and operate telemetry, tracking, and control (TCC) ground stations to support satellite missions on geostationary orbits with the use of Geostationary Satellite Launch Vehicle (GSLV) since 1997, in order to master and commercialize space technology. This cooperation needs to be assessed in order to identify how it will affect Indonesia and India and to establish an improvement strategy for improved business and ways to integrate. The objectives of this paper are to (i) evaluate the benefits and cost of this cooperation, (ii) map the business model of the telemetry, tracking and command ground station in Biak, and (iii) design a new strategy to get competitiveness. Descriptive analysis with canvas mapping and transaction cost perspective is the approach utilized. The article’s results highlight that (i) Indonesia and India have mutual benefits from tangible and intangible side, (ii) Indonesia has a competitive advantage due to its geographic location and commercialization of Biak Ground Station, so its potential to Telemetry, Tracking, and Command (TT&C) commercial businesses in the future, not only to domestic, but also international market, and (iii) Indonesia needs collaborate with commercial entities and making optimum diplomation with G2B schema to get beneficially among parties to maximize TT&C infrastructure in Biak Island.

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ABSTRACTIn this paper, the robust finite-time control for impact angle guidance of missile dynamic system with uncertainties is investigated by combining linear extended state observer (LESO) and adaptive non-singular fast terminal sliding mode method. Specially for dealing with existing uncertainties including time-varying parametric perturbation and nonparametric disturbances in high order line-of-sight rates and target acceleration, a robust LESO strategy is proposed for designing sliding mode-based impact angle guidance, which can guarantee that estimation error converges to the neighborhood of the origin in finite-time. Based on the proposed LESO framework, an adaptive non-singular fast terminal sliding mode guidance law is considered for realizing interception of maneuvering targets, which can guarantee asymptotically stability of the system. Simulation results are shown for confirming effectiveness of the proposed guidance strategy of this paper. Compared with former methods, accuracy of estimation is increased by nearly two times, and miss distance is reduced by nearly two times.

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ABSTRACT Understanding of various aerodynamic factors involved in flight trajectories is fundamental to design launch vehicles. First and foremost, computer simulation is an efficient way of predicting its behavior in the movement across the atmosphere. Considering that the available Brazilian version of Analysis, Simulation and Trajectory Optimization Software for Space Applications (Astos) does not simulate a controlled vehicle in six degrees of freedom (DoF), the aim of this article is to complement the Astos outcomes, particularly evaluating the trajectory of a controlled launch vehicle from liftoff to orbit injection, considering the model of rigid body dynamics with a six DoF. This approach carried out with an in-house developed simulator called Scott that simulated a multistage launcher with three flight configurations. In the Scott computer program, a launcher was modeled with differential equations in six DoF, coupled axes attitude control system, and aerodynamic coefficients that changed as a function of Mach number. These features improved the results generated by Astos software for the same configurations and the same initial conditions. Additionally, the results provided by Scott were close to actual vehicle in terms of attitude change and Mach number reached.

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ABSTRACT Gaussian mixture probability hypothesis density (GM-PHD) filtering often assumes a uniform distribution of clutter in the observation area. However, in practice, clutter is often unknown and non-uniform, necessitating accurate estimation of its spatial distribution, non-uniformity, and temporal variations. To address this problem, we proposed a modified GM-PHD filtering method with clutter density estimation for multiple target tracking. In the proposed method, first, potential target measurements within the tracking gate are eliminated to obtain the clutter measurement set. Next, the clutter density around each target is estimated. Finally, the estimated clutter density is incorporated into GM-PHD filtering, to estimate the target state and clutter density in complex clutter environments. Simulation results demonstrated that the proposed filtering method improves the performance of the GM-PHD filter in multi-target tracking scenarios with unknown clutter density.

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ABSTRACT This article provides a detailed look at how cyclotrimethylenetrinitramine (RDX), cyclotetramethylene-tetranitramine (HMX), and hexanitrohexaazaisowurtzitane (HNIW or CL-20) are currently being used for energy purposes in both civilian and military environments around the world. It highlights the significance of monitoring and prospecting for new technologies to promote innovation in developed and developing countries. This research was carried out by systematically analyzing nonpatent documents and patents from reputable databases such as Scopus, Derwent, and Espacenet. The report recognizes patent documentation as a valuable source of technical information and explores how analyzing patents can provide insights into using and developing high-performance compounds. Moreover, the article discusses the versatile applications of RDX, HMX, and CL-20, which are highly explosive substances that have found uses in multiple sectors. It delves into these materials’ chemical composition, structure, and importance in military and industrial contexts. The research methodology involved thoroughly searching and filtering documents from databases, focusing on titles, abstracts, and keywords. The results show the annual growth of publications related to the three explosive compounds and highlight the main research fields associated with each fabric. Overall, this article provides valuable insights into using and developing powerful compounds. It emphasizes the importance of technological monitoring and patent analysis in shaping strategic decision-making and fostering innovation. It is a foundation for further research and exploration of energetic materials and their applications.

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ABSTRACT Small multirotor unmanned aerial systems (sUAS) have become more accessible and efficient recently, spurring their development for various personal and commercial uses. However, this rapid evolution raises concerns about security, control, and public health due to the proliferation of noisy drones. This study focuses on investigating a major noise source in drones called rotor-airframe interaction, which generates tonal noise through pressure fluctuations and wake interactions. To address this issue, we designed and tested three airframes with varying arm configurations. High-definition microphones and data acquisition systems were employed to measure pressure levels, and MATLAB code helped analyze the data as A-weighted signals to identify noise reduction possibilities. The key finding was that motor noise was a significant contributor, producing multiple pure tones at mid and high frequencies. Additionally, the noise signature was heavily influenced by the arm’s geometric shape and angles, underscoring the complex nature of rotor-airframe flow and acoustic interactions.

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ABSTRACT This study investigates the issue of multi-objective mission planning for multi-payload satellite constellations via the non-dominated sorting carnivorous plant algorithm (NSCPA). Observation time windows are generated, and a constraint satisfaction model is established based on multiple regional targets, satellite orbits, and characteristics of the synthetic aperture radar (SAR) payload and optical payload. A task conflict detection and resolution method is proposed to handle the task assignment among multiple satellites. Based on the existing single objective-based CPAs, a modified multi-objective NSCPA is first developed for multi-objective planning optimization using the non-dominated sorting algorithm. The effectiveness and superiority of the NSCPA are verified by a series of simulation experiments and comparisons with the traditional non-dominated sorting genetic algorithms-II (NSGA-II) and particle swarm optimization (PSO).

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ABSTRACT The concept of a swarm of drones assumes the presence of a wireless ad hoc network, in which drones are network nodes and exchanging information with each other. This article is devoted to studying the behavior of an ad hoc network in a transient mode and assessing the characteristics of updating local adjacency matrices (LAM), which allow network nodes to autonomously form packet transmission routes. Using a simulation model, a comparison was made of two multiple access methods to a common data transmission channel in the process of updating matrices: cyclic and random (slotted ALOHA). The simulation results made it possible to determine areas of their effective application: slotted ALOHA is advisable to use with relatively high probabilities of packet distortion (of the order of 0.1 and higher), a numerous nodes (more than 40), and low network connectivity, and cyclic access (CA) is effective at a low level of distortion. It is shown that the completion of the process of updating adjacency matrices (AM) can be judged by such indicators of the exchange of routing information as the achievement of a certain threshold of the number of transmissions and a decrease in the level of network traffic.

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ABSTRACT The global increase in the number of passengers with disabilities in the aviation market raises the need for airlines to offer an inclusive service to these groups, which can represent a differentiation in the market. This paper is part 1 of a two-part series where it was proposed to apply a methodology inspired on Design Thinking, with tools such as persona mapping and user’s journey to define requirements and propose a concept for an accessible cabin. In this part, bibliographic research, with study of other papers that investigated the aviation market and mapped the complaints and needs of users with disabilities were initially carried out. The result of these researches served as the basis for the application of the methodology and definition of needs and requirements for an accessible cabin concept. It was concluded with this work that it is crucial to consider the needs of all stakeholders involved in the system for the good definition of the needs, that is, users, manufacturers, and airlines, since modifications to the cabin can affect important parameters such as cost and weight, and must be made to address points that can really improve the user experience. It was noted that research is limited for passengers with sensory impairments making it harder to clearly define their needs. Passengers with mobility restrictions, on the other hand, are better represented in research. Finally, the proposed list of needs demonstrates the potential to enhance the flight experience for passengers with special needs, potentially increasing their market share and overall satisfaction.

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ABSTRACT With modern technology, only a small percentage of the overall mass of a launch vehicle, usually less than 5%, can be used as payload mass. To achieve any acceptable performance, a key aspect that is exhaustively analyzed during vehicle design is the definition of the number and sizes of its stages. The problem of finding the best vehicle configuration for a given mission is called staging optimization. This work presents the formulation and a resolution method for the staging optimization of a launch vehicle. The problem is formulated as an optimal control problem (OCP) and, for its solution, a direct approach, employing a gradient-based algorithm as solver, is proposed. An application is performed for the Brazilian microsatellite launcher VLM-1. This vehicle has a notable characteristic that, in its nominal configuration, the first and second stages are very similar to each other (same solid rocket motor with the same quantity of propellant). Different vehicle configurations are investigated which result in an improvement in its performance. The obtained results show good agreement with those from a commercial optimization tool.

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Abstract Despite a global increase in the number of passengers with disabilities on regional aviation, most aircraft cabins are still not adequately equipped to provide sufficient comfort to this public, making the travel experience much less attractive. In order to investigate how airlines and aircraft manufacturers could improve the cabin’s accessibility, this study aims to investigate solutions and systems available in the market to propose an accessible cabin concept for regional aviation. This research is part 2 of a two-part series that aims to apply a methodology inspired by Design Thinking Tools such as persona mapping to suggest improvements for the experience of passengers with disabilities. To this end, potential systems were evaluated and a cabin concept was proposed. It was noted that for passengers with sensory impairments, it is possible to improve their experience without major cabin modifications. However, research on their needs is limited and there are few solutions on the market targeting this audience. Conversely, passengers with mobility restrictions pose more complex challenges. Finally, the proposed accessible cabin concept demonstrates the potential to enhance the flight experience for passengers with special needs, potentially increasing their market share and overall satisfaction.

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Abstract Recently, solar energy has become most favorable source of energy. It is sustainable and environmentally friendly, and one of the most common application of solar energy is the solar water heater, which has a wide commercial and domestic applications. To enhance the performance of this device, many modifications are recommended. The enhancements may involve changes in pipe shape or materials or in absorber plate manufacturing, or sometimes by using a thermal storage tank to maintain heating. In this study, a variable cross-sectional area pipe is used to enhance heat transfer. Firstly, the vertical length is increased at the outlet to 1.2-1.8 ratios, while the horizontal sides remain constant. Then, for the same ratio, the horizontal sides are varied while the vertical sides remain constant. Finally, both the vertical and horizontal sides are increase. A three-dimensional numerical analysis is used to investigate the conjugated heat transfer and the flow characteristics in the pipe under study for each case. FLUENT ANSYS 17.2 is used to achieve this analysis using finite volume technique. Energy, Navier-Stokes, and continuity equations are solved at constant heat flux condition for a range of Reynolds numbers from 100 to 500. The hydraulic-thermal function ε is adopted in this study. The best increase in ε is 48%, achieved in the case of changes to both vertical and horizontal dimensions at a ratio of 1.8. The lowest percentage of decrease in pressure drop is 9.7%, and the highest temperature difference found is and 45.5% for the same case when compared with the uniform case for Reynolds number of 100. The present work is validated with another study adopting Shah’s empirical relation with a very good agreement.

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ABSTRACT The aircraft manufacturing industry is critical to national defense and linked to various other industries. This paper explains the development of Korea’s aircraft manufacturing industry and the role of the government. Despite late entrance to the industry, Korea has developed and produced basic and jet trainers since the 1990s. In the meantime, the government has pursued technology sharing, integrated large companies, and provided financial incentives to manufacturers. It has also supported the strengthening of human capital and established a government research institute devoted to the aircraft manufacturing industry. In the early 2020s, Korea began to produce advanced fighter jets using its technologies. Based on Korea’s experience, this research presents policy implications for developing countries. The government must play a critical role in the aircraft manufacturing industry, which is an example of the infant industry argument. In the early stages of development, a developing country may learn advanced technologies through licensed production contracts and by requesting technology transfer when purchasing aircraft. It is necessary for the government to provide appropriate incentives, particularly for R&D activities, human capital development, and a dedicated government research institute in aircraft manufacturing. Moreover, regulating the number of domestic aircraft manufacturers may lead to greater efficiency.

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ABSTRACT The development of innovative technologies represents a fundamental pillar for economic and social progress in countries, and understanding the opportunities for utilizing these technological solutions is a critical success factor. The dynamics of the technology transfer (TT) process are determined by the peculiarities of factors related to both the consumer market and the business environment in which scientific and technological institutions (STIs) operate. In the aerospace and defense sector, technologies have high dual-use potential and interest various industrial sectors. This manuscript explores emerging trends and the potential for TT of the intellectual property (IP) portfolio of these STIs across a diversified spectrum of significant technological areas in the industrial sectors. It is a case study applied to public STIs, seeking to understand the trajectories of technological development and anticipate their impact on the Brazilian productive sector. This focus is relevant as it addresses critical aspects affecting research, development, and innovation (RD&I) in public STIs, which are all essential to deciphering the complexities of the contemporary technological innovation ecosystem. This study offers valuable insights for researchers and managers of RD&I and TT, highlighting the critical role of technology in understanding the dynamics of innovation and managing of RD&I in the sector in focus.

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ABSTRACT In this study, several composite beam samples were made from woven fiberglass and epoxy. The first sample was created using epoxy, whereas the others used epoxy together with fiberglass layers. These samples were used to study, experimentally and numerically, the effect of fiberglass layers on the natural frequency of composite beams. A numerical model was constructed using ANSYS software 17.2 to assess vibration properties for the manufactured samples. The effects of boundary conditions (simply supported, clamped-clamped, and clamped-free), with crack depths (2 mm and 3 mm) and the number of fiberglass layers (0, 1, 2, 3, and 4) were investigated. The results of the experimental and numerical models were compared, and the numerical model was acceptable with an error rate of less than 15%. Crack depth has a significant impact on natural frequency and mode shape; therefore, transverse cracks were created in the upper surfaces of beams to investigate the vibration mode shape and natural frequency.

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ABSTRACT In this paper, the modeling, open-loop analysis, and design of the constraint control system of the double-body aircraft are discussed. In a double-body aircraft configuration, two identical aircraft are connected using a one degree-of-freedom (1DOF) joint about the longitudinal body axis (hinges at the wingtips). Due to the long-term flight of the aircraft at high lift coefficients and the very high aspect ratio (AR) of the aircraft, controlling the angle of attack and the yaw rate is crucial to staying within safety limits. Additionally, the constraint control algorithm must be implementable in microprocessors to minimize weight and energy consumption. In the present research, a centralized control system with a sliding mode command governor (SMCG) is proposed to address these issues. First, the double-body aircraft was modeled using the Newton-Euler method. A nominal control system was designed with a linear control law, and then a SMCG is presented. To validate the constraint control system, numerical simulation and experimental testing were performed using a double-body simulation platform. The simulation and experimental test results indicate that the proposed control system performs well, with no deviation of the desired states from the limitations accrued.

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ABSTRACT The choice of the structure of the internet traffic exchange network is an urgent task for countries located with large areas. A mathematical model of this network with two Internet exchange points (IXes) in the form of a queuing network has been developed and analyzed. The proposed model, which, if necessary, can be generalized to the case of an arbitrary number of IXes, allows calculating the main characteristics of the network, determining its optimal parameters and analyzing alternative construction options: average round-trip delay (RTD), channel capacity, calculate the performance of traffic exchange nodes under reliability and cost constraints, and topology selection for the traffic exchange network, considering the main parameters. The results of calculations for Internet traffic exchange networks with uniform and significantly uneven loading of network channels are presented. An Internet traffic exchange network with several IXes can provide a lower delay, higher availability, and lower costs for implementation and commercial operation. In this case, a network with several IXes will enable the owners of these nodes and regional telecom operators to improve service and gain economic benefits.

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ABSTRACT The magnetic torquer rod, also called a magnetorquer, is the most popular actuator for attitude control of satellites in low Earth orbit. In the case of nano and picosatellites, the available inner space is quite limited, as is the maximum power value. An optimal design solution is highly desirable to produce adequate torque while minimizing energy consumption and mass. Based on the axiomatic design theory, a solution was developed by establishing the requirements – wire diameter, magnetic dipole moment, voltage, and solenoid length – and the physical domain variables – number of turns, current, resistance, and wire length. As a result of the modelling, the design system is decoupled. The choice of core material can also contribute to the actuator’s improvement. Two options are proposed in this work: the FINEMET, a nanocrystal composed of various metals and other elements, and the FeNi50 alloy, for comparative performance. In terms of design parameters, four prototypes were developed to evaluate different wiring configurations and two core materials. The test results of the design options reveal a contrasting performance concerning core material: while the utilization of nanocrystalline material yields superior hysteresis characteristics or linearity behavior, the FeNi50 alloy exhibits enhanced magnetization magnitude.

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ABSTRACT Optimizing pilot-automation collaboration necessitates early safety assessment of the aircraft, which involves a rigorous examination of potential scenarios. This article seeks to establish a comprehensive framework for safety analysis, exploring various levels of automation (LoA) within high-technology projects such as electric vertical takeoff and landing (eVTOL) aircraft. The method is divided into three phases: the first involves defining the operations concept; the second involves applying the systems theoretic process analysis (STPA) method; and the third encompasses determining the safest LoA. Furthermore, this article scrutinizes the landing operations of eVTOL aircraft in urban centers. The identified control actions (CAs) include flight monitoring, landing verification, speed selection, and maneuvering. Ultimately, a LoA categorized as automated decision making emerged as the safest. This entails the concurrent monitoring and generation of alternatives by both the pilot and the autopilot, with the final selection of the optimal alternative and its subsequent implementation exclusively entrusted to the autopilot. This work contributes by presenting evidence that safety analysis should commence at the level of individual CAs, rather than at a higher level encompassing complete operations or the entire aircraft. This approach aims to generate comprehensive, practical, and effective safety requirements.

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ABSTRACT This paper introduces a new method for synthesizing guidance laws for anti-tank guided missiles (ATGM) to intercept maneuvering tank targets. It utilizes a nonlinear relative model in the two-dimensional horizontal plane and optimal error dynamics (OED) theory. The nonlinear relative model simplifies the problem of targeting a moving target into attacking a stationary target, making the guidance law synthesis task easier. The selection of OED allows for the design of a guidance command that ensures the zero effort miss (ZEM) error decreases to zero within a finite time, ensuring successful target interception. The paper also introduces an exponential decay weighting function of remaining time-to-go to optimize the distribution of command accelerations throughout the guidance process, thereby reducing initial command requirements and converging acceleration commands towards zero at the end time. The synthesized guidance laws are derived based on the nonlinear relative model and OED without making any small-angle linearization assumptions, allowing them to address various nonlinear scenarios. Numerical simulations illustrate the proposed guidance law’s performance.

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ABSTRACT The aerospace industry continually seeks to optimize product development processes to remain competitive. Design for Excellence (DFX) plays a crucial role in meeting customer expectations while aligning with organizational capabilities. However, the diversity of DFX technological areas and methods can make it challenging for companies to select the appropriate ones for each project. Successful DFX application, ensuring projects stay within scope, time, cost, and quality constraints without overburdening the development process, often depends on the engineering team’s experience and the project phase. This work maps DFX technological areas to address the decision-making problem of selecting the most suitable ones for various projects. The objective is to evaluate, from the engineering team’s perspective, whether a general approach can guide project managers in selecting key DFX areas, considering a typical aerospace organization’s project portfolio and specific project phase characteristics. Starting with a literature review of DFX in aerospace, the research includes a survey along with senior product development engineers. Quantitative results are gathered using the Likert scale and analyzed through the analytic hierarchy process (AHP). The paper presents a method to guide the initial selection of DFX areas, aiding project managers and engineers in designing complex products.

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ABSTRACT The airspace is constantly adapting to efficiently absorb the growing traffic demand in the coming years and may therefore present bottlenecks for safety maintenance, especially in the Terminal Control Area (TMA), where the concentration of aircraft causes them to fly closer to each other. This paper presents a matrix of safety parameters to assess the perception of the safety level after modifications to the airspace, using the TMA from the state of São Paulo/Brazil, as an example for validation, following the implementation of the new airspace circulation in 2021. Through theoretical review, it was possible to delimit the study area and link related research to the presented matrix. The results indicated points of divergence among the surveyed stakeholders, such as speed adjustments which resulted in significant improvements for controllers, while for pilots, improvements were seen in traffic flow and waiting times. Overall, there was a positive perception regarding the decrease in workload in complex airspace, which translates into increased operational safety. Finally, areas for improvement were identified for future terminal designs, particularly regarding the need to reduce potential conflicts.

Abstract in English:

ABSTRACT This paper introduces a new method for synthesizing guidance laws for anti-tank guided missiles (ATGM) to intercept maneuvering tank targets. It utilizes a nonlinear relative model in the two-dimensional horizontal plane and optimal error dynamics (OED) theory. The nonlinear relative model simplifies the problem of targeting a moving target into attacking a stationary target, making the guidance law synthesis task easier. The selection of OED allows for the design of a guidance command that ensures the zero effort miss (ZEM) error decreases to zero within a finite time, ensuring successful target interception. The paper also introduces an exponential decay weighting function of remaining time-to-go to optimize the distribution of command accelerations throughout the guidance process, thereby reducing initial command requirements and converging acceleration commands towards zero at the end time. The synthesized guidance laws are derived based on the nonlinear relative model and OED without making any small-angle linearization assumptions, allowing them to address various nonlinear scenarios. Numerical simulations illustrate the proposed guidance law’s performance.

Abstract in English:

ABSTRACT The article provides a brief analytical review of mathematical models of the working process used to study the parameters and characteristics of a gas turbine engine at all stages of its creation and operation. It is shown that the first-level mathematical model can be used for the estimation of parameters and characteristics under real operating conditions that differ significantly from the calculated ones. A mathematical model of a mixed-flow turbofan engine with an afterburner is proposed in the article; the construction principle and structure of the mathematical model of the engine are given. The model allows solving various problems associated with calculating the performance of a mixed-flow turbofan engine with an afterburner in a wide range of external conditions and engine operating modes.

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ABSTRACT Operations management (OM) involves the activities related to producing goods by transforming input into output. Operations managers typically organize the design of goods and manage the processes to ensure a quality product. Many of these processes also apply to the future production of goods in space. Space resources are enablers for space travel and life on other bodies, but they must be processed from raw material to a finished good that can be used. Using terrestrial OM processes, we can imagine the procedures and processes needed to operate production plants in space. Some critical issues will be interoperability, sustainability, and high-quality control, but many other OM factors must be considered and explored.

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ABSTRACT A numerical simulation was executed by using of ANSYS Fluent to demonstrate the effect of a Gurney flap (GF) on a National Advisory Committee for Aeronautics (NACA) 662-015 airfoil. The GFs are remarkable aerodynamic elements that show how a small modification to an airfoil’s trailing edge can have a significant impact on performance, making them a valuable tool in the pursuit of enhanced efficiency and control in various applications with increased downforce and minimal drag penalty. The height of the flap was varied from 1% of the chord up to 3% of the chord of the airfoil, with 0.5% incremental steps. The increase in lift obtained and the subsequent penalty of increased drag were quantified in terms of percentage increase compared to the clean airfoil. As a result, the lift-to-drag ratio was found to be a net positive, with the most significant increase at a 2.5% GF height-to-chord ratio. Along with the lift augmentation, the impact of the GF on the zero-lift angle of attack, lift slope, and stall angle was investigated. Furthermore the alteration of the Kutta condition as a result of installing the GF on the airfoil. The improved aerodynamic effectiveness of airfoils using GFs is mostly observed in the motorsports and aviation sectors.

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ABSTRACT This work reports the development of an induction melting system for producing paraffin-based fuel units for hybrid rockets. The system is based in oscillating low-frequency magnetic field to generate heat within the material, enabling a precise temperature control through an on/off process. Additionally, the steel used as the material for fabricating the mold facilitates a slow cooling rate, leading to the formation of homogeneous paraffin fuel units free from cracks and microfractures, which is a critical requirement for their safe application in hybrid rockets and to ensure an efficient fuel combustion. The fabricated paraffin fuel units underwent rigorous characterization of their thermal, structural, and optical properties to ensure their suitability as fuel units in a hybrid rocket engine developed for the Mexican Cabo Tuna space program.

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ABSTRACT Computer simulations have been applied in several areas. Non-player characters in computer simulations are autonomous agents. An autonomous agent receives information from the simulated environment, processes this information, and estimates a situation awareness (state), makes a decision based on the estimated state, and performs an action related to the decision. The decision-making process of an autonomous agent can be efficiently modeled through behavior trees. However, teaching the construction of behavior trees for autonomous agents can be a very complex task, especially if students have little knowledge of computer programming. The objective of this work is to simplify this task. Therefore, I proposed the pyAutonomousAgent, an academic tool for modeling autonomous agent behaviors through behavior trees. The tool is an open-source set of computer routines, developed with the aim of being easy to use and learn. As a case study, the tool provides a simulation scenario with a swarm of drones. Results of the drone behavior modeling process are presented.

Abstract in English:

ABSTRACT With the increase in image production in recent years, there has been significant progress in the application of deep learning algorithms across various domains. Convolutional neural networks (CNNs) have been increasingly employed in remote sensing, covering all stages of target discrimination according to Johnson’s criteria (detection, recognition, and identification). These CNNs are applied in many conditions and imagery from many types of sensors. In this study, we explored the use of the YOLO-v8 method, the latest version of the You Only Look Once (YOLO) family of object detection models, in conjunction with CNN architectures and supervised learning algorithms. This approach was applied to detect, recognize, and identify targets in videos captured by optical sensors, considering varying resolutions and conditions. Additionally, our research investigated the use of two CNN architectures, Inception-v3 and VGG-16, to extract relevant information from the images. The attributes obtained from the CNNs were used as input for three classification algorithms: multilayer perceptron (MLP), logistic regression, and support vector machine (SVM), thereby completing the target discrimination process. It is worth noting that in the combination of Inception-v3 and MLP, we achieved an average accuracy of 90.67%, thus completing the target discrimination process.

Abstract in English:

ABSTRACT This study addresses the inadequacy of conventional failure analyses, which, in addition to regulatory and customer requirements, often neglect organizational needs. It emphasizes the importance of a systemic approach to mitigating hazards in complex space program management. This article proposes a new approach to addressing security issues that adds the management of security-related organizational needs to systemic engineering analysis. The case study of the catastrophic event involving SpaceX’s Starship SN10 prototype used publicly available information to build the system-theoretic accident model and processes (STAMP) model and identify organizational needs. The causal analysis based on systems theory (CAST) method was then applied to identify possible causes. Finally, the system-theoretic process analysis (STPA) method was used to determine design-related organizational needs and formulate recommendations for the design of the autogenous pressurization system. The presented method considered organizational needs to identify the key elements involved in the accident, the primary causes, and the actions to mitigate the associated hazards. This study proposed that managing organizational needs for system safety requires recognizing the current situation and constructing prospective scenarios to prevent failures, while emphasizing the importance of management’s proactive measures, clear responsibilities, and active involvement of all members to ensure system reliability.

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ABSTRACT In the concept, design, and development phases of suborbital payload scientific experiments, designers tend to focus on what will be tested using automation and procedures that support the vehicle and space environment. Although tests are the focus, safety is one of the primary areas that may contribute to a successful mission. This paper presents the typical Brazilian suborbital payloads and rockets, and then reviews some losses during the launching campaigns. The system-theoretic process analysis (STPA), which is based on the system-theoretic accident model and process (STAMP) approach, was used to identify 32 unsafe control actions (UCAs), 77 loss scenarios, and 28 safety constraints. These safety constraints were the basis for establishing 74 safety requirements modeled in systems modeling language (SysML). A group of experts in space systems evaluated these safety requirements, and a case study was performed to test the requirement set. The results may contribute to mitigating or eliminating hazards related to these space systems and launch mission safety.

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ABSTRACT During the penetration process of hypersonic glide vehicles (HGV), the maneuvering forms are varied, which brings some challenges for tracking them, such as difficulty in the stable matching of single-model tracking and the slow response of multi-model tracking. Therefore, this paper proposes an improved adaptive variable structure interacting multiple model tracking algorithm by analyzing the maneuvering characteristics of the target. The algorithm can switch between interacting multiple models and single-model tracking by defining a set of model-switching conditions. Additionally, it designs two correction functions and embeds them into the model probability update phase of the adaptive variable structure interacting multiple model algorithm, so that the proposed adaptive variable structure interacting multiple model algorithm can adaptively adjust the transition probability matrix (TPM) according to the probability law of the target maneuver model. Finally, the effectiveness and superiority of the proposed algorithm were verified through comparative simulation experiments with existing algorithms. Compared with the single-model tracking algorithm, the proposed algorithm’s position root mean square error is significantly reduced by nearly one-third, while also reducing the single running time by nearly one-fourth compared to other multi-model tracking algorithms.

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ABSTRACT Extended object tracking (EOT) is a prominent research area in high-resolution radar surveillance, ship tracking, and video tracking. However, EOT algorithms are susceptible to non-Gaussian noise from factors such as sensor performance and environmental conditions. To address this problem, the Gaussian process (GP)-based maximum correntropy criterion square root cubature Kalman filter algorithm (GP-MCC-SRCKF) for EOT in non-Gaussian noise environments is proposed in this paper. The proposed method utilizes a GP to model extended objects, thereby enhancing estimation accuracy. Furthermore, weighted least squares (WLS) and MCC are incorporated to construct a cost function. The proposed method considers high-order moments of estimation error and effectively handles outliers in non-Gaussian noise environments. MCC-SRCKF improves the accuracy of object state estimation in non-Gaussian noise environments while ensuring the positive definiteness and symmetry of the error covariance matrix. Finally, simulation experiments are conducted to demonstrate the effectiveness of the proposed method.