Joint preload properties of structural threaded fasteners

Proper installation techniques are described and reliable torque-tension values are presented on joint preload /or clamp load/ properties of structural threaded fasteners

Suspended Load Path Tracking Control Using a Tilt-rotor UAV Based on Zonotopic State Estimation

This work addresses the problem of path tracking control of a suspended load using a tilt-rotor UAV. The main challenge in controlling this kind of system arises from the dynamic behavior imposed by the load, which is usually coupled to the UAV by means of a rope, adding unactuated degrees of freedom to the whole system. Furthermore, to perform the load transportation it is often needed the knowledge of the load position to accomplish the task. Since available sensors are commonly embedded in the mobile platform, information on the load position may not be directly available. To solve this problem in this work, initially, the kinematics of the multi-body mechanical system are formulated from the load's perspective, from which a detailed dynamic model is derived using the Euler-Lagrange approach, yielding a highly coupled, nonlinear state-space representation of the system, affine in the inputs, with the load's position and orientation directly represented by state variables. A zonotopic state estimator is proposed to solve the problem of estimating the load position and orientation, which is formulated based on sensors located at the aircraft, with different sampling times, and unknown-but-bounded measurement noise. To solve the path tracking problem, a discrete-time mixed $\mathcal{H}_2/\mathcal{H}_\infty$ controller with pole-placement constraints is designed with guaranteed time-response properties and robust to unmodeled dynamics, parametric uncertainties, and external disturbances. Results from numerical experiments, performed in a platform based on the Gazebo simulator and on a Computer Aided Design (CAD) model of the system, are presented to corroborate the performance of the zonotopic state estimator along with the designed controller

Imagining a New Nation: Patriotism and National Identity in the Writing of Late-18th Century American Women

Benedict Anderson defined the nation as “an imagined political community” that is “imagined as both inherently limited and sovereign.” The research for this paper began with a desire to know how American women in the time leading up to, during, and immediately after the American Revolution and War of Independence did or did not imagine themselves as members of the newly emerging political community eventually known as the United States of America. As tensions between the Colonies and Great Britain increased, as tea was dumped in Boston harbor, and as independence was declared in 1776, how did women make sense of these events and their significance for their own identities? As many colonists began to reject their previous identity as British subjects and colonial residents in favor of a new civic identity as members of a separate, sovereign nation, they needed to define what it meant to be American. Who was an American citizen? What did it mean to be an American citizen? What was it that bound the disparate thirteen colonies and their diverse populations together into one cohesive nation? Where were the limits to this newly imagined community, and did these limits include or exclude women

Epistemic Harm in Empathy

This paper delves into the intricacies of the concept of epistemic harm. Particularly, epistemic harm is used as a case study to gain insights into the efficacy and distinctiveness of the concept of harm vis-à-vis related constructs such as violence and trauma within the domain of social psychology. The paper underscores the pertinence of the concept of epistemic harm in the context of empathetic testimonial exchange using autism studies as a sample case. Subsequently, empathy is characterised as innately engendering epistemic harm, manifesting both at the inter-subjective and intra-subjective levels. The paper concludes with a contemplation on the significance of the idea of epistemic harm within the broader field of harm research

Identity as a Determinant of the Overreporting of Church Attendance in Canada

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91358/1/j.1468-5906.2012.01640.x.pd

Set-based state estimation and fault diagnosis using constrained zonotopes and applications

This doctoral thesis develops new methods for set-based state estimation and active fault diagnosis (AFD) of (i) nonlinear discrete-time systems, (ii) discrete-time nonlinear systems whose trajectories satisfy nonlinear equality constraints (called invariants), (iii) linear descriptor systems, and (iv) joint state and parameter estimation of nonlinear descriptor systems. Set-based estimation aims to compute tight enclosures of the possible system states in each time step subject to unknown-but-bounded uncertainties. To address this issue, the present doctoral thesis proposes new methods for efficiently propagating constrained zonotopes (CZs) through nonlinear mappings. Besides, this thesis improves the standard prediction-update framework for systems with invariants using new algorithms for refining CZs based on nonlinear constraints. In addition, this thesis introduces a new approach for set-based AFD of a class of nonlinear discrete-time systems. An affine parametrization of the reachable sets is obtained for the design of an optimal input for set-based AFD. In addition, this thesis presents new methods based on CZs for set-valued state estimation and AFD of linear descriptor systems. Linear static constraints on the state variables can be directly incorporated into CZs. Moreover, this thesis proposes a new representation for unbounded sets based on zonotopes, which allows to develop methods for state estimation and AFD also of unstable linear descriptor systems, without the knowledge of an enclosure of all the trajectories of the system. This thesis also develops a new method for set-based joint state and parameter estimation of nonlinear descriptor systems using CZs in a unified framework. Lastly, this manuscript applies the proposed set-based state estimation and AFD methods using CZs to unmanned aerial vehicles, water distribution networks, and a lithium-ion cell.Comment: My PhD Thesis from Federal University of Minas Gerais, Brazil. Most of the research work has already been published in DOIs 10.1109/CDC.2018.8618678, 10.23919/ECC.2018.8550353, 10.1016/j.automatica.2019.108614, 10.1016/j.ifacol.2020.12.2484, 10.1016/j.ifacol.2021.08.308, 10.1016/j.automatica.2021.109638, 10.1109/TCST.2021.3130534, 10.1016/j.automatica.2022.11042

Private-Public Sector Cooperation in Combating Cybercrime: in Search of a Model

Turnover taxes are generally considered to be risk-free from the tax competition point of view, forthey are levied exclusively at the place of consumption. The Value-Added Tax (VAT) imposed by all EuropeanUnion (EU) member states, though, has become a source of distortion in the trans-Atlantic trade: non-EUsuppliers of electronic services were not required to collect the VAT, while their EU competitors were. The levelplaying field in EU’s foreign trade in electronic services was restored in 2002 by the so-called e-VAT Directivethat obliged non-EU providers of electronic services to charge the VAT at the rate of the member state theirconsumer resides in. This paper argues that besides being largely unenforceable, the Directive has createdanother misbalance in the infra-EU electronic commerce. It is being demonstrated that since the Directive is notapplicable to EU vendors, non-EU businesses can and do circumvent it by establishing daughter companies inEU jurisdictions with the lowest VAT rates and thus spur the infra-EU tax competition

Self Trapping of a Single Bacterium in its Own Chemoattractant

Bacteria (e.g. E. Coli) are very sensitive to certain chemoattractants (e.g. asparate) which they themselves produce. This leads to chemical instabilities in a uniform population. We discuss here the different case of a single bacterium, following the general scheme of Brenner, Levitov and Budrene. We show that in one and two dimensions (in a capillary or in a thin film) the bacterium can become self-trapped in its cloud of attractant. This should occur if a certain coupling constant $g$ is larger than unity. We then estimate the reduced diffusion D_eff of the bacterium in the strong coupling limit, and find D_eff ~ 1/g.Comment: 4 pages, absolutely no figure