Stone Observatory at Bric Pinarella (Finale Ligure, Italy)

This paper reports the latest findings on the stone observatory of Bric Pinarella (Finale Ligure, Savona, northern Italy), first described in 2006 at the conference of the Italian Society of Archaeoastronomy (SIA). The settlement is located near the upland plain of the Manie, which is an area known for the archaeological remains and the natural attractions. The settlement is constituted of three archaeological evidences: a small building, two short standing stones 44 centimetres apart, and a standing stone vertically fitted in the ground with a natural hole in its free end. Archeoastronomical investigations demonstrated that the hole in the standing stone allows positioning of the sunrise at the equinoxes over the Manie skyline, whereas the two standing stones allow tracing of the local meridian with azimuth 360-180. Other possible astronomical functions such as the identification of the elongation of the Sun from the east cardinal point and the study of the Sun and Moon's upper meridian transit (in this respect the site could be described as a rudimentary meridian circle) are discussed in the paper. Despite the fact that, to date, its construction time is still unknown, the most recent findings show that the whole site could be an old astronomical observatory

A bang controller for vibration reduction in a rotating flexible beam

The mathematical setting -- The case of a flexible beam -- Simulation results

Digital emancipation: Black musicians’ use of technology to disrupt socioeconomic barriers and epistemological bias within public school instrumental music programs

This research study explicates the underrepresentation of Black students in public school instrumental music programs through a critical race perspective, focusing on socioeconomic and epistemological barriers perpetuated by public policy and school music curricula. Such barriers have encouraged some Black musicians to seek agency and satisfy their musical interests in spaces outside of the classroom, particularly in the church and community. Considering that the theory of disruptive innovation purports the potential to increase access and disrupt both socioeconomic and epistemological barriers through the use of technology, this exploratory research study sought to investigate whether Black instrumental musicians use technology in order to disrupt the socioeconomic and epistemological barriers unveiled by a critical race perspective. By employing qualitative research methods, participants’ personal experiences were synthesized into a thematic analysis which ultimately support the potential of technology to increase access, revealing that participants successfully disrupted socioeconomic and epistemological barriers through the use of asynchronous online lessons

Application des diagrammes de Nyquist et de Black pour l'amélioration de la sensibilité

Relation entre l'erreur à chaîne fermée et l'erreur à chaîne ouverte -- Conditions indépendantes de l'entrée et de la perturbation extérieure -- Conditions dépendantes de l'entrée et de la perturbation extérieure

Path-tracking control for a tractor-trailer via input-output linearization

Vehicle's model -- Path tracking dynamics -- Path tracking control design -- An application example

Espaces de résolution Hilbertienne et théorie de la stabilité

Notions préliminaires -- Espaces de Résolution Hilbertienne -- Causalité, passiivité, et faible additvité -- Structure des systèmes bouclés par rapport à la stabilité -- Notion axiomatique de stabilité -- Systèmes équivalents du point de vue de la stabilité -- Stabilité, contraction, causabilité et passivité -- Applications : méthodes du cercle et de la ligne de Popov -- Méthode du cercle -- Méthode de la ligne de Popov

Dynamique des systèmes mécaniques sous contraintes holonomes et non holonomes

Cinématique d'un ensemble de corps rigides -- Dynamique d'un corps rigide -- Dynamique d'un ensemble de corps rigides -- La procédure de modélisation -- Le cas d'un manipulateur robotique -- Modélisation d'un tracteur-remorque -- Modélisation d'un robot mobile avec roues motrices indépendantes

Practical sensitivity reduction tests for linear and nonlinear systems

Main results -- Determination of sensitivity improvement -- Compensator design procedure -- Determination of sensitivity improvement from normal operating data -- The case of the nonlinear compensator

Sensitivity-Based Model of Low Voltage Distribution Systems with Distributed Energy Resources

A key issue in Low Voltage(LV) distribution systems is to identify strategies for the optimal management and control in the presence of Distributed Energy Resources (DERs). To reduce the number of variables to be monitored and controlled, virtual levels of aggregation, called Virtual Microgrids (VMs), are introduced and identified by using new models of the distribution system. To this aim, this paper, revisiting and improving the approach outlined in a conference paper, presents a sensitivity-based model of an LV distribution system, supplied by a Medium/Low Voltage (MV/LV) substation and composed by several feeders, which is suitable for the optimal management and control of the grid and for VM definition. The main features of the proposed method are: it evaluates the sensitivity coefficients in a closed form; it provides an overview of the sensitivity of the network to the variations of each DER connected to the grid; and it presents a limited computational burden. A comparison of the proposed method with both the exact load flow solutions and a perturb-and-observe method is discussed in a case study. Finally, the method is used to evaluate the impact of the DERs on the nodal voltages of the network