Proofs of Control of a Quadrotor and a Ground Vehicle Manipulating an Object

This paper focuses on the control of a cooperative system composed of an Unmanned Aerial Vehicle (UAV) and an Unmanned Ground Vehicle (UGV) manipulating an object. The two units are subject to input saturations and collaborate to move the object to a desired pose characterized by its position and inclination. The dynamics are derived using Euler-Lagrange method. A pre-stabilizing control law is proposed where the UGV is tasked to deploy the object to a certain position whereas the UAV adjusts its inclination. In particular, a proportional-derivative control law is proposed for the UGV, and a cascade control approach is used for the UAV, where the inner loop controls the attitude of the UAV and the outer loop stabilizes the inclination of the object. Then, we prove the stability of the points of equilibrium using small gain arguments. To ensure constraints satisfaction at all times, a reference governor unit is added to the pre-stabilizing control scheme. Finally, numerical results combined with experimental results are provided to validate the effectiveness of the proposed control scheme in practice.Comment: 16 pages, 7 figure

Developing Modified ADS-33D Helicopter Maneuvers for the Shipboard Environment

The Office of the Secretary of Defense chartered the Joint Shipboard Helicopter Integration Process (JSHIP), Joint Test and Evaluation (JT&E) Program to improve Joint interoperability between U.S. Navy ships and U.S. Army/Air Force helicopters. One effort of the JSHIP JT&E Program was to improve the modeling and simulation tools and fidelity levels associated with conducting Joint shipboard helicopter operations, for both testing agencies and operational users. The UH-60A helicopter and the LHA class ship were identified as the highest priority helicopter-ship pair for operational forces and also allowed JSHIP to enhance models that currently existed. Enhancing the visual model of an LHA ship was a primary effort for the research and testing community in order to accurately replicate the shipboard visual cueing environment. Evaluating enhanced visual models in a research flight simulator in order to reduce actual shipboard flight testing or expand wind launch/recovery envelopes required the use of more aggressive and precise flight maneuvers than standard shipboard takeoffs and landings. The U.S. Army’s Aeronautical Design Standard 33D (ADS-33D) contained flight test industry accepted maneuvers of sufficient aggressiveness and precision, but were not designed for, or intended to be flown from the deck of a ship at sea. The methodology and procedure used to modify selected ADS-33D flight maneuvers so that they could safely be executed aboard an LHA class ship is presented in this thesis, along with the final maneuver descriptions, locations, and flight tolerances. The results of the shipboard test program and follow-on simulator assessment are not presented here, as they fall outside the scope of this thesis. However, conclusions from the at-sea flight tests relating to development of the modified ADS-33D were included. The flight test philosophy, methodology, and lessons learned while developing the modified ADS-33D maneuvers for the shipboard environment are the primary conclusions drawn

Tridendriform structures

We first study tensor products of tridendriform algebras in order to introduce the notion of tridendriform bialgebra. We shall need for this a notion of augmented tridendriform algebras. Inspired by the work of J-L. Loday and M. Ronco, we build free tridendriform algebras over reduced trees and show that they have a coproduct satisfying some compatibilities with the tridendriform products. Such an object will be called a (3, 1)--dendriform algebra. Studying the free (3, 1)--dendriform bialgebra over one generator, we describe its products and coproduct in a combinatorial way. The products are described by branches shuffle and the coproduct by admissible cuts. We compare it with quasi-shuffle algebras over words. Its graded dual is the bialgebra TSym introduced by N. Bergeron and al which is described by the lightening splitting of a tree. As a consequence, this shows that TSym has a (1, 3)--dendriform bialgebra structure. This means that its coproduct can be split in three parts with convenient compatibilities. This can be extended to (3, 1)-bialgebras over an arbitrary number of generators. Finally, we introduce the notion of (3, 2)--dendriform bialgebra. This is a Hopf algebra, where we can split the product in three pieces and the coproduct in two with Hopf compatibilities. We give an example of such an algebra built on the free (3, 1)-dendriform bialgebra with one generator. We describe and generate its codendriform primitives and count its coassociative primitives thanks to L. Foissy's work. We end this paper by showing that a quotient of this (3, 2)-dendriform bialgebra is the Loday-Ronco bialgebra

The Cartier-Quillen-Milnor-Moore theorem in the Post-Hopf case

We give the definition of left/right Post-Lie algebras and left/right Post-Hopf algebras and establish a link between those objects. We get a Cartier-Quillen-Milnor-Moore theorem for Post-Hopf algebras. We give another description for free Post-Lie algebras and a description for Post-Lie algebras obtained from an associative product

Educational Policy Decisions Effect Upon Same-Gender Public Education

The No Child Left Behind (NCLB) Act of 2001, with emphasis on greater choice and flexibility for parents and students in public education, to include the provision for same-gender public schools and classrooms, led to a resurgence in same-gender public education in the United States. With the results of the research on same-gender education presenting conflicting evidence and mixed-perspectives on the outcomes of same-gender education in improving academic achievement or attainment, there are still questions to be answered, not only to the effectiveness of same-gender education, but also to policy decisions to establish same-gender public education programs. While proponents of same-gender public education advocate that same-gender schooling supports increased educational opportunity and achievement while freeing students from gender stereotypes, opponents claim separate but equal is discriminatory and unconstitutional. As a result, public policy decisions by local educational agencies to establish same-gender public education programs, no matter how well intentioned, and irrespective of the provisions for same-gender schools and classrooms within NCLB, can be left open to questions on the rationales, justifications, and resources behind such decisions. This non-experimental, mixed methods study gathered and analyzed data on same-gender public education programs in the United States using a descriptive cross sectional survey with telephone interviews to question principals of 92 K-12 same-gender public schools on the proponents, rationales, justifications, resources, and metrics behind decisions to establish and maintain same-gender public education programs. Fifty-four respondents agreed the establishment and maintenance of same-gender public education programs results from actions of local educational agencies and the leadership of the same-gender school, and they agreed this leadership is knowledgeable on the requirements for same-gender public education programs. Respondents to the study also agreed school choice for low-income students is a key reason for the establishment of same-gender public schools. Respondents to the study further agreed that supplementary funding, whether federal, state, or local, was not critical in the establishment and maintenance of same-gender public education programs

An Overview of the NOAA ENC Re-Scheming Plan

The scheme (or footprints) of NOAA Electronic Navigational Charts (ENCs) are based on traditional paper/raster charts from which they were derived. As a result, modernizing current ENC coverage to improve the way they are displayed in a digital environment, increase their level of detail, and incorporate additional survey data outside of the existing bounds is complex. As part of NOAA’s “ENC-First” effort, a re-scheming approach was developed to provide a seamless, tiled coverage that can easily be segmented or extended based on geographic location, available data and scale. In this new regular gridded ENC coverage approach, fewer than a dozen chart scales are used (down from the current 130 scales used in the paper chart scheme). The re-scheme plan also aims to improve products for mariners who prefer paper charts. The uniform scales will enable mariners to create customized charts with a new online application. Additionally, NOAA has created one production line for both ENC and Raster Navigational Charts (RNCs) products that will reduce production resources for maintaining two chart products.El esquema (o el bosquejo) de las Cartas Náuticas Electrónicas (ENCs) de la NOAA se basa en las cartas tradicionales de papel/ráster de las que se derivaron. Como resultado, la modernización de la cobertura ENC actual para mejorar el modo en el que se visualizan en un entorno digital, aumentar su nivel de detalle e incorporar datos de levantamientos adicionales fuera de los límites existentes, es compleja. Como parte del esfuerzo de la NOAA «ENC-First», se desarrolló un enfoque en materia de restructuración para proporcionar una cobertura sin interrupciones y en forma de mosaico, que puede ser fácilmente segmentada o ampliada basándose en la ubicación geográfica, los datos disponibles y la escala. En este nuevo enfoque de cobertura ENC reticulada regular se utilizan menos de una docena de escalas de cartas (por debajo de las 130 escalas actuales utilizadas en el esquema de cartas de papel). El plan de restructuración también tiene por objeto mejorar los productos para los navegantes que prefieran las cartas de papel. Las escalas uniformes permitirán a los navegantes crear cartas personalizadas con una nueva aplicación en línea. Además, la NOAA ha creado una línea de producción para ambos productos, las cartas ENCs y Ráster (RNCs), que reducirá los recursos de producción para el mantenimiento de dos productos cartográficos.Les schémas (ou empreintes) des cartes électroniques de navigation (ENC) de la NOAA sont basés sur les cartes traditionnelles papier/raster à partir desquelles ils ont été tirés. En conséquence, la modernisation de la couverture en ENC actuelle afin d’améliorer la manière dont ces dernières sont affichées dans un environnement numérique, d’accroître leur niveau de détail, et d’incorporer des données de levés supplémentaires au-delà des limites existantes, se révèle compliquée. Dans le cadre de l’initiative « ENC-First » de la NOAA, une approche de reschématisation a été développée afin de fournir une couverture maillée continue pouvant aisément être segmentée ou étendue en se basant sur la localisation géographique, les données disponibles et l’échelle.  Dans le cadre de cette nouvelle approche d’une couverture en ENC maillée de manière régulière, moins d’une douzaine d’échelles cartographiques sont utilisées (bien moins que les 130 échelles actuellement utilisées dans le schéma de cartes papier). Le plan de re-schématisation vise également à améliorer les produits pour les navigateurs qui préfèrent les cartes papier. L’uniformité des échelles permettra aux navigateurs de créer des cartes personnalisées avec une nouvelle application en ligne. En outre, la NOAA a créé une ligne de production à la fois pour les produits ENC et pour les cartes de navigation raster (RNC), ce qui réduira les ressources de production pour la tenue à jour de deux produits cartographiques

Provably Secure Mobile Key Exchange: Applying the Canetti-Krawczyk Approach

info:eu-repo/semantics/publishe