Modelling and Verification of Multiple UAV Mission Using SMV

Model checking has been used to verify the correctness of digital circuits, security protocols, communication protocols, as they can be modelled by means of finite state transition model. However, modelling the behaviour of hybrid systems like UAVs in a Kripke model is challenging. This work is aimed at capturing the behaviour of an UAV performing cooperative search mission into a Kripke model, so as to verify it against the temporal properties expressed in Computation Tree Logic (CTL). SMV model checker is used for the purpose of model checking

On mathematical modelling of insect flight dynamics in the context of micro air vehicles

This paper discusses several aspects of mathematical modelling relevant to the flight dynamics of insect flight in the context of insect-like flapping wing micro air vehicles (MAVs). MAVs are defined as flying vehicles ca six inch in size (hand-held) and are developed to reconnoitre in confined spaces (inside buildings, tunnels etc). This requires power-efficient, highly-manoeuvrable, low-speed flight with stable hover. All of these attributes are present in insect flight and hence the focus of reproducing the functionality of insect flight by engineering means. This can only be achieved if qualitative insight is accompanied by appropriate quantitative analysis, especially in the context of flight dynamics, as flight dynamics underpin the desirable manoeuvrability. We consider two aspects of mathematical modelling for insect flight dynamics. The first one is theoretical (computational), as opposed to empirical, generation of the aerodynamic data required for the six-degrees-of-freedom equations of motion. For these purposes we first explain insect wing kinematics and the salient features of the corresponding flow. In this context, we show that aerodynamic modelling is a feasible option for certain flight regimes, focussing on a successful example of modelling hover. Such modelling progresses from first principles of fluid mechanics, but relies on simplifications justified by the known flow phenomenology and/or geometric and kinematic symmetries. In particular, this is relevant to six types of fundamental manoeuvres, which we define as those steady flight conditions for which only one component of both the translational and rotational body velocities is non-zero (and constant). The second aspect of mathematical modelling for insect flight dynamics addressed here deals with the periodic character of the aerodynamic force and moment production. This leads to consideration of the types of solutions of nonlinear equations forced by nonlinear oscillations. In particular, the existence of non-periodic solutions of equations of motion is of practical interest, since this allows steady recitilinear flight. Progress in both aspects of mathematical modelling for insect flight will require further advances in aerodynamics of insect-like flapping. Improved aerodynamic modelling and computational fluid dynamics (CFD) calculations are required. These theoretical advances must be accompanied by further flow visualisation and measurement to validate both the aerodynamic modelling and CFD predictions

Experimental investigation of some aspects of insect-like flapping flight aerodynamics for application to micro air vehicles

Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for micro air vehicles for indoor applications. Some aspects of the aerodynamics associated with the sweeping phase of insect wing kinematics are examined by making particle image velocimetry measurements on a rotating wing immersed in a tank of seeded water. The work is motivated by the paucity of data with quantified error on insect-like flapping flight, and aims to fill this gap by providing a detailed description of the experimental setup, quantifying the uncertainties in the measurements and explaining the results. The experiments are carried out at two Reynolds numbers-500 and 15,000-accounting for scales pertaining to many insects and future flapping-wing micro air vehicles, respectively. The results from the experiments are used to describe prominent flow features, and Reynolds number-related differences are highlighted. In particular, the behaviour of the leading-edge vortex at these Reynolds numbers is studied and the presence of Kelvin-Helmholtz instability observed at the higher Reynolds number in computational fluid dynamics calculations is also verified

Повстання Хмельницького у «Вогнем і мечем» Генріка Сенкевича, в «Переяславській раді» Натана Рибака та в історичній публіцистиці Павла Ясениці

Порівняно два історичні романи, що змальовують надзвичайно драматичний і переломний історичний момент для Польщі та України - повстання Богдана Хмельницького: «Вогнем і мечем» / енріха Сенкевича та «Переяславська рада» Натана Рибака. Ті самі або споріднені проблеми, явища й процеси, пов’язані з цим історичним моментом, нерідко одні й ті ж персонажі показано з іншого погляду, оцінюються за цілком іншими критеріями. Отже, романи є наче аверсом і реверсом однієї епохи. Історична публіцистика Павла Ясениці служить мірилом історичної правди

Airborne mapping of complex obstacles using 2D Splinegon

This paper describes a recently proposed algorithm in mapping the unknown obstacle in a stationary environment where the obstacles are represented as curved in nature. The focus is to achieve a guaranteed performance of sensor based navigation and mapping. The guaranteed performance is quantified by explicit bounds of the position estimate of an autonomous aerial vehicle using an extended Kalman filter and to track the obstacle so as to extract the map of the obstacle. This Dubins path planning algorithm is used to provide a flyable and safe path to the vehicle to fly from one location to another. This description takes into account the fact that the vehicle is made to fly around the obstacle and hence will map the shape of the obstacle using the 2D-Splinegon technique. This splinegon technique, the most efficient and a robust way to estimate the boundary of a curved nature obstacles, can provide mathematically provable performance guarantees that are achievable in practice

Reducing Versatile Bat Wing Conformations to a 1-DoF Machine

Recent works have shown success in mimicking the flapping flight of bats on the robotic platform Bat Bot (B2). This robot has only five actuators but retains the ability to flap and fold-unfold its wings in flight. However, this bat-like robot has been unable to perform folding-unfolding of its wings within the period of a wingbeat cycle, about 100 ms. The DC motors operating the spindle mechanisms cannot attain this folding speed. Biological bats rely on this periodic folding of their wings during the upstroke of the wingbeat cycle. It reduces the moment of inertia of the wings and limits the negative lift generated during the upstroke. Thus, we consider it important to achieve wing folding during the upstroke. A mechanism was designed to couple the flapping cycle to the folding cycle of the robot. We then use biological data to further optimize the mechanism such that the kinematic synergies of the robot best match those of a biological bat. This ensures that folding is performed at the correct point in the wingbeat cycle

Computational Approaches to the Nuclear Many-Body Problem

The nuclear many-body problem is conceptualized in an infinite-dimensional Hilbert space, but computationally solved in a finite one. Thus, the predictive power of microscopic calculations relies on the truncated representation of the infinite-dimensional space as well as leveraging advanced computational methods. My dissertation research focuses on three problems related to computational nuclear physics: exploring aspects of nuclear structure, efficiently solving the large sparse matrix-eigenvalue problem and improving the construction of the many-body basis in the no-core configuration-interaction (NCCI) framework. I) Elliott’s rotational SU(3) model, and its later extension, the symplectic Sp(3, R) model, both played a foundational role in improving the description of nuclear rotational spectral bands. My study of several beryllium isotopes, and 20Ne uses the decomposition of no-core shell-model wavefunctions into symmetry defined subspaces to show the Sp(3, R) picture provides a more consistent description of rotational band structure. II) Solving the non-relativistic many-body Schrödinger equation is often cast as a large sparse Hamiltonian eigenvalue problem. State-of-the-art NCCI calculation dimensions can exceed several billion and typically require supercomputers and thousands of core hours to compute small numbers of low-lying eigenstates. Thus, there is strong motivation for ways to reduce computational costs. In this research, I augment the block Lanczos algorithm using a bootstrapped pivot to significantly reduce the number of Hamiltonian-matrix multiplications typically dominating the algorithm’s total time-to-solution. My results demonstrate significant speedup in time-to-solution, often by a factor of two or more, and up to ten, can be achieved through the use of bootstrapping. III) In NCCI, the many-body basis is historically constructed from antisymmeterized products of harmonic oscillator (HO) single-particle wavefunctions. However, one often needs many HO antisymmeterized products states to produce accurate theoretical predictions of the properties of low-lying nuclear states. Alternative choices of single-particle basis which provide better descriptions of nuclear observables relative to the problem dimension and underlying basis parameters motivate continued explorations. In this research, I explore the use of a natural orbital (NO) single-particle basis, that is, one which diagonalizes the one-body density matrix of a reference many-body state, as a means of improving the description of energy, electromagnetic transitions and radii calculations relative to the problem dimension for select sd-shell nuclei

Digital Is Not Enough

Throughout the course of this text I will be discussing the relationship my art practice shares with various modes of digital manipulation. Discussions of the “device” and how it is inevitably the source for manipulation of information and how these paintings are using this notion as a subject matter to create a conversation about illusions in contemporary digital culture. A thorough analysis of my artistic practice reveals how my process of making in the studio relates to these illusions and forms of digital image making. Painting methods have been appropriated by digital, in the form of virtual toolboxes and filters, and my works re-appropriate these digital painting methods and effects to create my own language and to suggest that digital manipulation is not enough

Aeroservoelastic modelling and control of a slender anti-air missile for active damping of longitudinal bending vibrations

Slender anti-air missiles experience longitudinal bending in supersonic flight and yet their autopilots are designed under the rigid-body assumption. Such autopilot design employs notch filters to remove the modal frequencies of the elastic airframe but this approach limits the autopilot bandwidth. In this paper, aeroservoelastic modelling and control of the ASTER 30 missile is proposed to enable autopilot design with extended bandwidth. The aeroservoelastic model combines missile flight dynamics, actuator dynamics and airframe elasticity, the latter focusing on longitudinal bending treated as a continuous Euler–Bernoulli beam problem. The beam is discretised leading to a nodal model and the modal analysis is then performed. The modal model is expressed in the state-space form and its order is reduced to enable optimal sensor placement and active damping control. The aeroservoelastic model of the ASTER 30 missile is further refined for control purposes by optimally choosing actuator inputs together with the number and position of sensors to be mounted on the missile airframe. Once these choices are made, several variants of active vibration damping control are proposed and analysed in order to enable an extended bandwidth for the autopilot by countering the airframe deformation measured by these sensors

Automated Telephone Monitoring for Relapse Risk among Recent Quitters Enrolled in Quitline Services

poster abstractThis study is part of a randomized controlled trial to test the efficacy of interactive voice response (IVR) technology for enhancing existing quitline services (Free & Clear’s Quit for Life® program) to prevent smoking relapse and achieve abstinence. The IVR system screens for six indicators of risk for relapse including smoking lapse, physical withdrawal symptoms, depressive symptoms, perceived stress, decreased self-efficacy for quitting, and decreased motivation to quit. Participants can screen positive on any one or more risks, resulting in a rollover call to a telephone counselor. There are two intervention arms that differ in timing and frequency of IVR screening. In the Technology Enhanced Quitline arm (TEQ-10), 10 automated calls are placed at decreasing frequency for 8 weeks post-quit (twice a week for the first two weeks, then weekly). The High Intensity Technology-Enhanced Quitline arm (TEQ-20) includes 20 IVR calls (daily for the first 2 weeks, then weekly). This preliminary analysis includes IVR data collected on calls from 4/12/2010 to 10/31/2010. 2620 calls were made to 98 participants in the two intervention arms, TEQ-10 (n=44) and TEQ-20 (n=54). The two arms did not differ significantly on demographics or comorbid conditions. Three outcomes were analyzed: completed screening assessments, positive screen for relapse risk, and smoking lapse (i.e., smoking even a puff since the last call). 136 of the 736 (18.5%) completed assessments were positive for relapse risk: 66 for smoking lapse (49%), 42 craving (31%), 32 depressive symptoms (24%), 27 lack of confidence (20%), 8 stress (6%), and 8 lack of motivation (6%). Logistic regression models (adjusted for age and gender), with GEE estimation to account for withinperson correlation, showed that compared to the TEQ-10 study group, participants in the TEQ-20 study group were more likely to complete assessments (OR=1.7; 95% CI=1.2-2.4), less likely to screen positive for relapse risk (OR=.3; 95% CI=.2-.6), and less likely to have smoked (OR=.2; 95% CI=.09-.4). These results indicate that frequent IVR monitoring during the immediate postquit period may have a positive effect on relapse risk