Flight Dynamics and Control

In today's era, facial recognition is common in every aspect of life, whether in smartphones, security, attendance management, healthcare, or law enforcement. Modern facial recognition uses a camera mounted in different locations in urban environments but is unable to move if a suspect is hidden in locations where the mounted camera can't trace easily. Therefore, we need to use a moving object equipped with a camera and sensors to monitor suspects wherever they are present in the urban vicinity. To solve this problem, this experimental study proposes optimizing the performance of facial recognition parameters for real-time suspect detection through drone imaging and face recognition algorithms in urban environments. To achieve this, the Unmanned Aerial Vehicle is equipped with a high-definition camera and sensors, allowing it to fly in predefined urban locations and capture images to find the suspected individual through the image processing technique Convolutional Neural Networks (CNNs). In this research, the performances of three facial recognition systems, Local Binary Pattern Histogram (LBPH), FaceNet, and Face Recognition, have been presented for Frames Per Second, Accuracy, and real-time tracking. A comparative analysis of the proposed work is also presented to validate the study, where a minimum confidence threshold of 80% is achieved.

Given a desired signal y d = (y d i ) i∈{0,...,N } , we investigate the optimal control, which applied to nonlinear discrete distributed system x i+1 = Ax i + E x i + Bu i , to give a desired output y d . Techniques based on the fixed point theorems for solving this problem are presented. An example and numerical simulation is also given.

Given a desired signal y d = (y d i ) i∈{0,...,N } , we investigate the optimal control, which applied to nonlinear discrete distributed system x i+1 = Ax i + E x i + Bu i , to give a desired output y d . Techniques based on the fixed point theorems for solving this problem are presented. An example and numerical simulation is also given.

Traditional aircraft designs rely on rigid wings with limited capabilities and adaptability. However, nature's flying creatures-birds, bats, and insects-achieve extraordinary agility and efficiency through dynamic wing morphing. This paper explores how bio-inspired origami mechanisms can revolutionize the field of aircraft wing design. By integrating folds which are inspired by avian wing structures and beetle elytra, we can demonstrate how morphing wings can improve manoeuvrability, fuel efficiency, and the overall performance in turbulent environments.

Control allocation compute the commands that are applied to the actuators so that a certain set of forces or moments are generated by the control effectors. In this communication we consider the problem of the design of an airborne system whose function is to solve the problem of allocation of transportation aircraft actuators during manoeuvres. The case of a roll manoeuvre, which may be quite demanding for the wings structure, is more particularly considered. The aim of this supervision function, similar to the load alleviation function, is to control the bending and flexion moments of the wings while performing a manoeuvre which can turn to be extreme. The wings actuators considered are the ailerons, the spoilers and the flaps, but the other aerodynamic actuators, elevators and rudders, must be considered to take into account the existing coupling effects between the three body axis. The proposed approach may be applied specially in the case in which some of the actuators are failed (stuck to a particular deflection or flapping in the wind stream) while theirs limitations, such as position, speed and response time, are considered explicitly in this study.

We study a model of fluent material universe from a modified Newtonian cosmology proposed by D’Inverno [1] and Tawfik [2]. From this perspective, it shows a list of space-time curvature k with energy E, density ρ, specific heat Cp and the fluid temperature gradient considered ∆T corresponding to standard thermodynamic variables. We determined the coupling constants accompanying the matter density for different values we can take k. PACS numbers: 04.,04.20-q,04.70Bw,05.20.Gg INTRODUCCIÓN Consideremos una cosmologı́a newtoniana sin constante cosmológica, tal como lo plantea Inverno[1], asumiendo que el universo se compone de una cierta cantidad materia en el sentido clásico, tal que la posición y velocidad de todas las partı́culas se pueden medir desde cierto punto O. Ademas de imponer que el Principio Cosmológico sea válido en este con-texto. Tawfik muestra que al estudiar este tipo de cosmologı́a y teniendo en cuenta los efectos viscosos de un modelo de universo se puede obten...

The dynamics of a model describing the hepatitis B viral infection model with cytotoxic T-lymphocyte and antibody responses is studied in this paper. The model consists of a system of differential equations describing the interaction between hepatocytes, the free virus and the immune responses. Both the treatment and the intracellular delay are incorporated into the model. Existence, positivity and boundedness of solutions are investigated. Also, the existence of the optimal control pair is established and the Pontryagin's minimum principle is used to characterize these optimal controls. The optimal controls represent the efficiency of drug treatment in inhibiting viral production and preventing new infections. The optimality system is derived and solved numerically using the forward and backward difference approximation. The obtained results show that the optimal treatment strategies reduce the viral load and then increase the uninfected hepatocytes, this improves the patient life quality.

Direct lift control (DLC) has been integrated into the L-1011 All Weather Landing System design to enhance the performance and safety capabilities of this Category TTT aircraft. The merits of the improved aircraft behavior achieved with DLC not only provide a higher degree of performance capability for a large vehicle of this nature, but are also firmly reflected in many subtle areas relating to the design, safety margin, and reliability of a  complex, fail operational all weather landing system. The result in terms of influence on autoland system design,
problems and limitations that constrained the design, and resulting improvements in performance and safety characteristics are the subject of this paper'

In recent years, the semi-active control of structural vibrations has interested several researchers. It has been demonstrated that semi-active control strategies are economical solutions for the safety of structure against earthquake or wind excitations. In this study, a semi active device which utilizes the Magneto-Rheological fluid characteristics to dissipate the earthquake excitation energy is proposed. The Magneto-Rheological damper is adopted to control the undesired vibrations of an earthquake-excited structure. Furthermore, a sliding mode controller coupled to the Clipped optimal algorithm is proposed to control this semiactive device. Otherwise, the sliding mode controller is reinforced by an adaptive gain law and the effectiveness of the new proposed adaptive controller to control the structural earthquake vibrations is proved by the compared numerical simulation results of the controlled and uncontrolled structure. Thus, the improvement of the sliding mode controller through the adaptive gain law is proved by the evaluation indices of an excited three-story scaled structure. Hence, a comparison between the results of the proposed adaptive sliding mode controller and the uncontrolled structure under the El Centro 1940 and the Boumerdès 2003 earthquakes excitations are discussed.

Yakıt çalkalanma dinamiğinin uçak dinamiğine etkisi olabilmektedir. Uçağın hareketleri neticesinde oluşan ivmeler yakıtın belli bir yöne doğru yığılmasına veya çalkalanma hareketi yapmasına yol açabilmektedir. Bu hareket neticesinde uçağın ağırlık merkezi ve atalet değerleri değişebilmektedir. Bu çalışmada bu etkinin yansıtılabilmesi için öncelikle yakıtın çeşitli koşullardaki denge durumları hesaplanmış, sonrasında da ikinci derece bir yakıt dinamiği modeli eklenerek yakıt yüzeyinin anlık açıları bulunmuştur. Bu anlık açılar neticesinde oluşan ağırlık merkezi ve atalet değişimleri hesaplanarak uçak dinamiğine etkileri incelenmiştir.

This paper discusses the design and development of a quad-rotor platform for the International Aerial Robotics Competition (IARC) that is to be held in the summer of 2013. The paper is about the design of a quad-rotor that, in addition to being stable at the time of flight, is able to hover autonomously, recognize and pick objects as per its requirement. A considerable amount of research was done in order to choose methodologies and controlling techniques that would be feasible for the project. A number of achievements have been made, including the design and implementation of different parts of the quad-rotor, such as the power distribution board, controller board, sensors for attitude and height sensing, and wireless communication setups for remote control over-ride purposes. In addition, a pre-fabricated controller board is experimented on and attempts are made to control the quad-rotor wirelessly through a PC, for the sake of using this methodology as a parallel plan (Plan B) fo...

Tuned mass dampers (TMD) have been widely used as one of vibration controlled devices in order to reduce the response of buildings subjected to lateral loads such as earthquake loads. Although the optimal design of TMD subjected to earthquake has received much attention of researchers, finding the most severe earthquake for this purpose has been well-known a challenging task. Hence, this paper proposes the optimal design of TMD subjected to continuous stationary critical excitation as the most severe earthquake. The continuous stationary critical excitation is determined by maximizing structural responses. In this study, the optimal parameters of TMD are determined through minimizing the sum root of the mean square of story drifts defined in the frequency domain. For achieving this purpose, at first, the performance of the improved gravitational search algorithm (IGSA) is verified using a ten story shear building with a TMD as a benchmark example. The numerical results demonstrate that IGSA converges to better solutions in comparison with other algorithms. Finally, the optimal design of TMD parameters obtained for the ten story shear building subjected to the continuous stationary critical excitation. Tuned mass dampers • Continuous stationary critical excitation • Optimal parameters • Frequency domain • Story drift • Improved gravity search algorithm B Mohsen Khatibinia

The most powerful LabSat yet, the new LabSat 3 WIDEBAND captures and replays more GNSS signals at a much higher resolution than before. Small, battery powered and with a removable solid state disk, LabSat 3 WIDEBAND allows you to quickly gather detailed, real world satellite data and replay these signals on your bench. With three channels, a bandwidth of up to 56MHz and 6 bit sampling, LabSat 3 WIDEBAND can handle almost any combination of constellation and signal that exists today, with plenty of spare capacity for future planned signals.

A multiple models with two level adaptation control method for nonlinearly parameterized nonlinear system is proposed in this article. The proposed adaptive control technique is well suited for controlling nonlinear systems having unknown parameters. An estimation model of the system is designed to tune the unknown parameters. Moreover, the estimation error is shown to converge to zero asymptotically at the first level and the closed loop stability of the overall system after two level is proved using the Lyapunov stability criterion. Furthermore, different configurations for adaptive control using multiple models and selection of the optimum number of models is also reviewed. A cart-pendulum system and an academic example is simulated and results are presented. The improvement in transient and steady state performance as well as better parameter convergence using the proposed scheme are shown as compared to existing single model methods.

Nowadays, unmanned aerial vehicles take an important place in our life. There are several studies on UAVs. UAVs can be classified according to their propulsion systems like Turbofan UAVs, Turbojet UAVs or Electrical UAVs. Propellers are used to supply the thrust force to Electrical UAVs. It is difficult to obtain available performance data of micro propellers. Also, micro propeller has operated at low Reynold number, so that performance of micro propeller is obtained difficultly. Basic propeller thrust test system is needed to determine the characteristic of propeller. It is known that the characteristic of propeller has great effect on thrust force and torque which are produced by the propeller. Thrust force and torque take important place in UAVs performance. Also, Thrust force can be used to control UAVs in the flight control system. In this paper, PID controller for basic propeller thrust test system was designed and simulated for static thrust condition.

We investigate the dynamics of a driven Van der Pol-Duffing oscillator circuit and show the existence of higher-dimensional chaotic orbits (or hyperchaos), transient chaos, strange-nonchaotic attractors, as well as quasiperiodic orbits born from Hopf bifurcating orbits. By computing all the Lyapunov exponent spectra, scanning a wide range of the driving frequency and driving amplitude parameter space, we explore in twoparameter space the regimes of different dynamical behaviours.

The solvability conditions for positive real and *-norm controller synthesis problems are expressed in terms of linear matrix inequalities that include the compensator gains implicitly. A variety of issues, including explicit expressions for the solutions, the issue of strictly proper vs proper controllers and relaxing full rank assumptions on the penalty matrices can be discussed. Extension to systems with parametric uncertainties is also discussed.

The problem of modelling end point control of a one-linkflexible manipulator has been considered. The assumed mode methodas well as the Lagrangian dynamics are used to develop the dynamicmodel. It has been shown that a conventional computed torquecontroller cannot deal with the end point vibrations of flexiblelinks. The non-minimum phase characteristic of the end pointcontrol of a one link flexible

Maintenance in the aviation industry has evolved considerably since commercial and general aviation became a modern mode of transportation. ICAO has made maintenance a top priority by directing local National Aviation Authorities, NAA, to have implemented, robust and standardized training and qualifications for all maintenance personnel that work on any safety critical structure or component. There are rules, law and standards that are audited and the aviation industry is, perhaps, the most successful industry in maintaining standards and reliability. With the advent of Unmanned Aerial Vehicles, UAV, the role of maintenance is now needing to be reviewed to determine how and what is needed. This research paper reviews the concepts and importance of maintenance in this new and expanding industry and the complexity of having international standards for engineers to support continuous airworthiness.

Tests in the Ames 40-by 80-foot wind tunnel of the static longitudinal characteristics of the Republic RF -84F were made to determine both the origin and a suitable remedy for a pitch up tendency of the airplane encountered at moderate lift coefficients. The results indicated that the pitch-up at moderate lift coefficients was caused by an abrupt change in downwash at the tail which in turn was traceable presumably to flow conditions associated with the inlet-to-wing leading-edge discontinuity.. Attempts to eliminate this pitch-up characteristic with various fairings and stall-control devices. were not wholly successful. The investigation revealed, however, that significant gains in the performance of the airplane could be achieved in the upper lift range.. Three different configurations consisting of a partial-span modified leading edge combined with one or with two-fenees or a leading-edge extension each delayed the onset of separation to higher lift coefficients and provided large improvements in the stability of the airplane in the upper lift range.

Tests in the Ames 40-by 80-foot wind tunnel of the static longitudinal characteristics of the Republic RF -84F were made to determine both the origin and a suitable remedy for a pitch up tendency of the airplane encountered at moderate lift coefficients. The results indicated that the pitch-up at moderate lift coefficients was caused by an abrupt change in downwash at the tail which in turn was traceable presumably to flow conditions associated with the inlet-to-wing leading-edge discontinuity.. Attempts to eliminate this pitch-up characteristic with various fairings and stall-control devices. were not wholly successful. The investigation revealed, however, that significant gains in the performance of the airplane could be achieved in the upper lift range.. Three different configurations consisting of a partial-span modified leading edge combined with one or with two-fenees or a leading-edge extension each delayed the onset of separation to higher lift coefficients and provided large improvements in the stability of the airplane in the upper lift range.

A study has been made of the application of two-dimensional data and span-loading theory for estimating the local loading characteristics on a swept wing with flaps. Estimated results, including local pressure distributions, span loadings, and the nonlinear local lift characteristics, are compared with similar results measured at large scale on a 45 0 sweptback wing of aspect ratio 6 having a O.4-epan double-elotted flap both with and without a full-span slat. Two-dimensional pressure distributions when corrected for sweep were found to agree closely with the wing pressures for most local sections either on or off the flap. This agreement continued to the higher lift coefficients and even improved near maximum lift where the flap-induced effects became minimized. The Weissinger 7Xl method was found to provide reasonably accurate span lciadings for this awept-wing configuration which had a relatively highly loaded type of flap. Twodimensional lift data, together with span-loading theory, afforded quite accurate estimates of the local nonlinear lift characteristics, includiLg maximum lift of sections outboard of the flap but were inadequate for inboard sections of the wing where the three-dimensional boundary-layer control exercises a dominant effect.

Control allocation compute the commands that are applied to the actuators so that a certain set of forces or moments are generated by the control effectors. In this communication we consider the problem of the design of an airborne system whose function is to solve the problem of allocation of transportation aircraft actuators during manoeuvres. The case of a roll manoeuvre, which may be quite demanding for the wings structure, is more particularly considered. The aim of this supervision function, similar to the load alleviation function, is to control the bending and flexion moments of the wings while performing a manoeuvre which can turn to be extreme. The wings actuators considered are the ailerons, the spoilers and the flaps, but the other aerodynamic actuators, elevators and rudders, must be considered to take into account the existing coupling effects between the three body axis. The proposed approach may be applied specially in the case in which some of the actuators are failed (stuck to a particular deflection or flapping in the wind stream) while theirs limitations, such as position, speed and response time, are considered explicitly in this study.

This paper presents design of the sliding mode controller (SMC) via a nonlinear disturbance observer (NDO) for stabilization of the rotational pendulum. The mathematical model is depicted by four first-order nonlinear differential equations with two outputs and single input. The linear model is obtained by linearizing nonlinear equations. This linearized version is found to be highly unstable. The applied NDO is capable of estimating extremely nonlinear terms (disturbance) present in the model. Then, the NDO based SMC is designed using linear model and disturbance estimation, and hence is applied to the original nonlinear system. The developed controller is enough to drive a sliding surface (which holds both actuated and unactuated dynamics) attaining the sliding mode against severe nonlinearities existing in the model, in addition large parameter variations and/or external disturbance. The sliding coefficients are determined using the linear quadratic regulator (LQR) technique. The obtained controller parameters can establish the zero dynamics as of sliding mode dynamics asymptotically. Also, the proposed control algorithm has potential to alleviate the chattering phenomenon occurred in the control signal. Overall, the control scheme expands the stability region of an arm (in horizontal half-plane) and a pendulum (over vertical half-plane) both for large initial conditions. Lastly, numerical simulations and quantitative measurements are validated with an established controller in the literature.

The  aim  of  this  article  is  to  analyse  the  employment  of  Private  Military  Companies  (PMC’s)  inmilitary  operations  and  UN  missions.  The  PMC’s  operate  throughout  the  world,  commissioned  by  governments,  intelligence agencies, private industries, warlords, drug cartels and rebel groups to support their militaries and investments. These companies share not only similar  corporate  aims  but  also  a  professional  ethos;  they  are  largely  run  and  staffed by  ex-military personnel. The existing literature conf irms the fact that Africa is the largest theatre of PMC’s operation next to Iraq and Afghanistan (GWATIWA,  2016).  This  phenomenon  continues  to  raise  serious  concerns  to  the  national  armed  forces,  as  most  governments  are  still  reliant  on  their  military forces to protect their borders and vital interests. Traditionally military function has been known to be the sole responsibility of the state; (SINGER, 2008) however, the PMCs are continuing to infringe on that mandate. The international  system  has  undergone  a  signif icant  change  since  the  United  States (US) terrorist attack incident in September 2011, where the PMC’s has become broadly acceptable elements of the Global War on Terrorism (GWT). Therefore,  this  article  will  look  into  the  employment  of  PMCs  in  different  countries  and  analyse  the  trend  and  legalities  involved.  Finally,  a  conclusion  will be drawn to identify measures to curb or minimise the threats posed by PMCs to state militaries and military operations.

In this paper, a control law that enforces an output tracking of a fractional diffusion process is developed. The dynamical behavior of the process is described by a space-fractional parabolic equation. The objective is to force a spatial weighted average output to track its specified output by manipulating a control variable assumed to be distributed in the spatial domain. The state feedback is designed in the framework of geometric control using the notion of the characteristic index. Then, under the assumption that the fractional diffusion process is a minimum phase system, it is shown that the developed control law guarantees exponential stability in L 2 -norm for the resulting closed loop system. Numerical simulations are performed to show the tracking and disturbance rejection capabilities of the developed controller. Keywords Distributed parameter system • fractional partial differential equation • fractional diffusion • late lumping • geometric control • characteristic index.

Unmanned aerial vehicles (UAVs) require effective path planning algorithms to navigate through complex environments. This study investigates the application of Deep Q-learning and Dyna Q-learning methods for UAV path planning and incorporates fuzzy logic for enhanced control. Deep Q-learning, a reinforcement learning technique, employs a deep neural network to approximate Q-values, allowing the UAV to improve its path planning capabilities by maximizing cumulative rewards. Conversely, Dyna Q-learning leverages simulated scenarios to update Qvalues, refining the UAV's decision-making process and adaptability to dynamic environments. Additionally, fuzzy logic control is integrated to manage UAV movements along the planned path. This control system uses linguistic variables and fuzzy rules to handle uncertainties and imprecise information, enabling real-time adjustments to speed, altitude, and heading for accurate path following and obstacle avoidance. The research evaluates the effectiveness of these methods individually, with a focus on model-free learning in a gradual training approach, and compares their performance in terms of path planning accuracy, adaptability, and obstacle avoidance. The paper contributes to a deeper understanding of UAV path planning techniques and their practical applications in various scenarios.

A Traditional physiotherapy sessions are long and demanding, requiring a lot of effort and time from both the physiotherapist and the patient. The KUKA LWR's high work capacity and consistent precision of end-effector location and movement were utilized to solve these issues. The KUKA LWR is a seven-degrees-of-freedom robotic manipulator designed for applications in which the robot must be near the human operator. During shoulder flexion exercises, which are commonly employed in traditional physiotherapy sessions, the robotic system pretends to analyze upper-limb behaviour, specifically the shoulder complex.

Q1. Define the concept of stability in aviation and its significance. Ans: Stability in aviation refers to an aircraft's ability to maintain or return to its initial flight condition after being disturbed by external forces such as turbulence, control inputs, or environmental changes. Stability is a fundamental characteristic of an aircraft's design and operation, ensuring safety, efficiency, and ease of control. Stability encompasses how the aircraft responds immediately and over time to disturbances, playing a crucial role in flight dynamics and its performance.

This paper presents a disturbance attenuation controller for horizontal position stabilization for hover and automatic landings of a Rotary-wing Unmanned Aerial Vehicle (RUAV) operating in rough seas. Based on a helicopter model representing aerodynamics during the landing phase, a nonlinear state feedback H ∞ controller is designed to achieve rapid horizontal position tracking in a gusty environment. The resultant control variables are further treated in consideration of practical constraints (flapping dynamics, servo dynamics and time lag effect) for implementation purpose. The high-fidelity closed-loop simulation using parameters of the Vario helicopter verifies performance of the proposed position controller. It not only increases the disturbance attenuation capability of the RUAV, but also enables rapid position response when gusts occur. Comparative studies show that the H ∞ controller exhibits great performance improvement and can be applied to ship/RUAV landing systems.

This paper presents a disturbance attenuation controller for horizontal position stabilization for hover and automatic landings of a Rotary-wing Unmanned Aerial Vehicle (RUAV) operating in rough seas. Based on a helicopter model representing aerodynamics during the landing phase, a nonlinear state feedback H ∞ controller is designed to achieve rapid horizontal position tracking in a gusty environment. The resultant control variables are further treated in consideration of practical constraints (flapping dynamics, servo dynamics and time lag effect) for implementation purpose. The high-fidelity closed-loop simulation using parameters of the Vario helicopter verifies performance of the proposed position controller. It not only increases the disturbance attenuation capability of the RUAV, but also enables rapid position response when gusts occur. Comparative studies show that the H ∞ controller exhibits great performance improvement and can be applied to ship/RUAV landing systems.

System identification is a challenging and interesting engineering problem that has been studied for decades. In particular, the NARMAX methodology has been extensively used with interesting results. Such methodology identifies a deterministic parsimonious model by ranking a set of candidate terms using a linear dependency metric with respect to the output. Other metrics have been used that identify nonlinear dependencies, like the mutual information, but they are hard to interpret. In this work, the distance correlation metric is implemented together with the bagging method. These two implementations enhance the performance of the NARMAX methodology providing interpretability of nonlinear dependencies and uncertainty measures in the model identified. A comparison of the new BOFR-dCor (Bagging Orthogonal Forward Regression using distance Correlation) algorithm is done with respect to the traditional OFR (Orthogonal Forward Regression) algorithm and the OFR-MI (Orthogonal Forward Regression using Mutual Information) algorithm showing interesting results that improve interpretability and uncertainty analysis.

A blended-wing-body is an example of an aircraft configuration with multiple control surfaces. The most effective use of these control surfaces, e.g. to minimize cruise drag due to pitch trim, or to maximize pitching moment at low speed in an engine-out condition, leads to optimization problems. The method investigated is this paper is applied to multiple control surfaces, taking into account their mutual interactions and also the influence of shifts of center of gravity. It is shown in a particular case that it is possible to achieve pitch trim in cruise with drag reduction relative to the untrimmed case.

Wall temperature variations significantly influence the stability and transition dynamics of hypersonic boundary layers. This study numerically investigates the stability response to thermal gradients, with wall temperatures ranging from 262 K to 362 K, for double-cone and cone-cylinder-flare (CCF) geometries. The CCF geometry, modeled using data from the Research Task Group NATO-AVT-346, consists of a 5°half-angle cone followed by a 147.3 mm cylindrical section and a 12°flare, with the sharp-nosed variant (0.1 mm nose radius) analyzed to emphasize instability mechanisms such as the first and second Mack modes. For the double cone, modeled after the ROTEX-T flight-test vehicle (457.31 mm in length, 1 mm nose radius, and 7°half-angle) at Mach 5.7, flow conditions were representative of the AFOSR-Notre Dame Large Mach 6 Quiet Wind Tunnel. Heating the entire wall stabilized second-mode instabilities while amplifying the first mode, particularly within the separation bubble. In contrast, for the CCF geometry, wall heating upstream of the separation bubble consistently stabilized both first-and second-mode instabilities throughout the flowfield. Numerical stability analyses were conducted using the JoKHeR Parabolized Stability Equations (PSE) code. These results underscore the geometry-dependent nature of thermal stabilization strategies and suggest that targeted upstream heating can effectively suppress boundary layer instabilities and delay transition in hypersonic flows.

Wall temperature variations significantly influence the stability and transition dynamics of hypersonic boundary layers. This study numerically investigates the stability response to thermal gradients, with wall temperatures ranging from 262 K to 362 K, for double-cone and cone-cylinder-flare (CCF) geometries. The CCF geometry, modeled using data from the Research Task Group NATO-AVT-346, consists of a 5°half-angle cone followed by a 147.3 mm cylindrical section and a 12°flare, with the sharp-nosed variant (0.1 mm nose radius) analyzed to emphasize instability mechanisms such as the first and second Mack modes. For the double cone, modeled after the ROTEX-T flight-test vehicle (457.31 mm in length, 1 mm nose radius, and 7°half-angle) at Mach 5.7, flow conditions were representative of the AFOSR-Notre Dame Large Mach 6 Quiet Wind Tunnel. Heating the entire wall stabilized second-mode instabilities while amplifying the first mode, particularly within the separation bubble. In contrast, for the CCF geometry, wall heating upstream of the separation bubble consistently stabilized both first-and second-mode instabilities throughout the flowfield. Numerical stability analyses were conducted using the JoKHeR Parabolized Stability Equations (PSE) code. These results underscore the geometry-dependent nature of thermal stabilization strategies and suggest that targeted upstream heating can effectively suppress boundary layer instabilities and delay transition in hypersonic flows.

Coronaviruses are types of viruses that are widely spread in humans, birds, and other mammals, leading to hepatic, respiratory, neurologic, and enteric diseases. The disease is presently a pandemic with great medical, economical, and political impacts, and it is mostly spread through physical contact. To extinct the virus, keeping physical distance and taking vaccine are key. In this study, a dynamical transmission compartment model for coronavirus (COVID-19) is designed and rigorously analyzed using Routh-Hurwitz condition for the stability analysis. A global dynamics of mathematical formulation was investigated with the help of a constructed Lyapunov function. We further examined parameter sensitivities (local and global) to identify terms with greater impact or influence on the dynamics of the disease. Our approach is data driven to test the efficacy of the proposed model. The formulation was incorporated with available confirmed cases from January 22, 2020, to December 20, 2021, and parameterized using real-time series data that were collected on a daily basis for the first 705 days for fourteen countries, out of which the model was simulated using four selected countries: USA, Italy, South Africa, and Nigeria. A least square technique was adopted for the estimation of parameters. The simulated solutions of the model were analyzed using MAPLE-18 with Runge-Kutta-Felberg method (RKF45 solver). The model entrenched parameters analysis revealed that there are both disease-free and endemic equilibrium points. The solutions depicted that the free equilibrium point for COVID-19 is asymptotic locally stable, when the epidemiological reproduction number condition (R 0 < 1). The simulation results unveiled that the pandemic can be controlled if other control measures, such as face mask wearing in public areas and washing of hands, are combined with high level of compliance to physical distancing. Furthermore, an autonomous derivative equation for the five-dimensional deterministic was done with two control terms and constant rates for the pharmaceutical and non-pharmaceutical strategies. The Lagrangian and Hamilton were formulated to study the model optimal control existence, using Pontryagin's Maximum Principle describing the optimal control terms. The designed objective functional reduced the intervention costs and infections. We concluded that the COVID-19 curve can be flattened through strict compliance to both pharmaceutical and non-pharmaceutical strategies. The more the compliance level to physical distance and taking of vaccine, the earlier the curve is flattened and the earlier the economy will be bounce-back.

A flight recorder, commonly referred to as a black box, is regarded as the most crucial source of information in the investigation of air accidents. Since the 1950s, flight recorders have been recognized as essential components of onboard equipment for both military and civilian aircraft worldwide. These devices are invaluable not only for analyzing flights after unexpected incidents but also for pilot training, evaluating pilot skills, diagnosing onboard systems, and assessing the performance of aircraft systems. Consequently, flight recorders play a significant role in ensuring high aircraft reliability and aviation safety. This research project introduces a digitalized Flight Data Recorder (FDR) system designed for light aircraft, aimed at enhancing aviation safety. The primary objective of this system is to accurately record essential flight parameters to improve the analysis and understanding of aircraft performance and safety. The system integrates with various sensors, including accelerometer, Pitot tube with airspeed sensor. The paper looks at methodology, design issues and testing steps of the Flight Data Recorder (FDR) system development. In fact, the early stages of this project showed that it had a reliable and accurate system during test flights as well as for collecting and monitoring critical flight data. The following areas will see the integration of more sensors in tandem with AI-driven functionalities to enhance its capacity further. These findings provide insights into how important these advanced FDR systems are for light aircraft operations. This AI-enhanced FDR system uses state-of-the-art technology to improve aviation safety.

A triple slotted aerofoil following the Handley Page 44F design was tested at City University London T-2 wind tunnel. The model allowed the study of a fixed triple slotted wing as well as investigation of the effects of isolated slots at different locations along the chord. PIV measurements were performed within the chord Reynolds number range in between approximately 200,000-400,000. The model was tested at an angle of attack of 22o. Measurements of mean streamwise velocity, velocity fluctuations and shear stress were analysed. The study shows how an isolated slot is more favourable when it is placed closest to the leading edge, although slow moving fluid regions can still be found close to the trailing edge. Fully attached flow was only achievable by using all three slots. In addition, the fully slotted profile is shown to generate channel exit velocities in the order of 1.4U∞, which highly energise the boundary layer on the suction side.

The present literature review aims to analyze the impact of COVID-19 on job performance and mental health in employees in the aviation industry, especially pilots from an organizational industrial perspective. In a study aimed at identifying the implications of COVID-19 on pilots' mental health, Flyn et al. found that, by January 2021, airlines eliminated thousands of jobs while 24 airlines ended operations. In surveys of the general population of pilots, it was identified that 13% of people had "severe distress" due to the pandemic. Whereas, in two aviation-focused surveys, between 40% and 66% of pilots agreed or strongly agreed that their mental health had worsened since the COVID-19 pandemic. Compared to previous patients with severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), more patients with COVID-19 presented mental health symptoms in the acute phase of the disease. In contrast, about 10% of COVID-19 patients appeared to have chronic or "long-lasting" symptoms (Flyn et al., 2022, p.1). The findings and information reviewed allow us to establish that no organizational development in many aviation industries in the world promotes their employees' mental health, psychological well-being, and crisis management. Industrial/organizational psychologists promote prevention for optimal employee performance in any organization, so the intervention of such health professionals is recommended to create an optimal work environment in the aviation industry.

Bir helikopterde ana rotor palleri (pervaneler) hava akışı oluşturmak maksadıyla döner ve bu esnada da kaldırma ve geri sürükleme kuvveti meydana getirirler. Rotor sisteminin dönüşü sabit bir hızda muhafaza edilir ve kaldırma kuvveti, her bir ana rotor palinin hücum açısı artırılarak oluşturulur. Pallerin hücum açılarının artırılması, pilot tarafından kokpitte bulunan kollektif adı verilen kumandanın yukarı doğru tatbik edilmesi suretiyle gerçekleştirilir.

Majority of Digital Signal Processing (DSP) applications require arithmetic blocks such as multipliers and adders for hardware realization of complex algorithms. Power consumption of arithmetic blocks need to be minimized by use of low power techniques. In this paper, an experimental setup is developed to identify the sources of power dissipation and remedies that can be adopted to minimize power dissipation in arithmetic blocks. Use of low power techniques such as Multi V t , variable V t , pipelining, geometry scaling and use of appropriate load capacitance have been used to reduce power dissipation. A 4-bit pipelined adder is designed and the power dissipation is reduced to 4.17µW from 9.6µW. The designed pipelined adder can be used for DSP applications.

There exists growing interest in the use of Unmanned Aerial Vehicles (UAVs) for missions that would otherwise be dangerous or tiresome for human pilots. Such UAVs require obstacle avoidance or Sense and Avoid (S&A) capabilities for autonomous operation. However, small UAVs do not possess the power or structure to handle heavy, expensive, and energy-consuming sensors or computers. The purpose of this research was to develop and demonstrate an inexpensive obstacle avoidance capability on a quadrotor UAV using commercial-off-the-shelf (COTS) components. The research was constrained to indoors testing, where GPS signals are inaccessible and the UAV must rely on its inertial measurement unit (IMU) for navigation.