Hydro-Thermal Vent Mapping with Multiple AUV's AZORES-2001

LONG TERM GOAL: The Naval Postgraduate School (NPS) and the Instituto Superior Tecnico, Lisbon (IST) have a long standing memorandum of agreement dating back to 1994 for the exchange of scientific ideas, visits of faculty and students, and to perform collaborative work. In the past we have collaborated on joint papers, the shared supervision of doctoral work, and a shared effort on the evaluation of AUV control system methodology. This is a NICOP project aimed at developing the technology of multiple cooperating AUV's in a shallow water vent-mapping mission. The missions to be conducted in the AZORES Islands will develop multi-vehicle cooperative strategies and control using radio and acoustic communications. Results of both sonar and video images will be obtained in which the Portuguese vehicle – INFANTE, and a surface catamaran (DELFIM) will perform broad area survey to identify vent clusters, while the NPS vehicle – ARIES, will be used to reacquire vent cluster locations, and perform local area searches with close in video data gathering.Award # N0001400AF0000

Analise e desenvolvimento do processo de obtenção de fibras de carbono a partir da estabilização oxidativa das fibras de poliacrilonitrila

Orientadores: Edison Bittencourt, Jose Luis Gomes da SilvaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuimicaResumo: A utilização de fibras de carbono em compósitos estruturais torna necessário o conhecimento dos fenômenos envolvidos durante sua obtenção. O estudo da estabilização oxidativa da poliacrilonitrila (PAN) é fundamental pois nessa etapa, a fibra torna-se susceptível a transformações morfológicas que influenciam diretamente as propriedades das fibras de carbono. O objetivo deste trabalho foi o desenvolvimento e otimização do processo de obtenção da PAN oxidada (PANOX) a partir da poliacrilonitrila, por meio de um conjunto de técnicas de caracterização para monitorização do processo e da proposta de um modelo matemático de difusão do oxigênio durante a estabilização oxidativa. O controle das reações químicas, das modificações morfológicas e estruturais, durante a estabilização oxidativa, foram acompanhadas por programas analíticos. Técnicas de espectrometria no infravermelho, ressonância magnética nuclear e análise elementar orgânica foram utilizadas para a avaliação das propriedades químicas. Temperaturas de transição vítrea (Tg) e ciclização, fluxo de calor, perda de massa e estabilidades térmica e dimensional foram obtidas por análises térmicas. Índice de aromatização, ordenamento lateral e índice de cristalinidade foram obtidos por difração de raios-X. A concentração de oxigênio reagido foi monitorizada por determinação de massa específica e observação da seção transversal das fibras por microscopia eletrônica de varredura (MEV) e relacionada com as propriedades mecânicas das fibras de carbonoAbstract: The utilization of carbon fibres in structural composites makes necessary the knowledge of the involved fenomena during its production. It is important to study the oxidative stabilization of Polyacrylonitrile (PAN), since at this stage the fiber becomes susceptive to morphological transformations that affect directly the carbon fibers properties. The aim of this work was to develop and opmize the process of obtaining oxidized PAN (PANOX) from polyacrylonitrile by means of characterization techniques to monitorate the process, and the proposal of a mathematical model of oxygen diffusion during the oxidative stabilization. Analytical techniques were used to follow up chemical reactions and the structural and morphological changes. Infra-red spectroscopy, nuclear magnetic resonance and elemental analysis technique were used to evaluate the chemical properties. Glass transition temperature (Tg) e ciclyzation, heat flow, weight loss and thermal and dimensional stability were determined by thermal analysis. Aromatization and crystalinity indices and lateral ordering were obtained by X-ray diffraction. The reacted oxygen concentration, was monitored by the determination of the fiber density and the observation of transversal section of the fibers by the carbon fibersDoutoradoCiencia e Tecnologia de MateriaisDoutor em Engenharia Químic

A Velocity Algorithm for the Implementation of Gain-scheduled Controllers

A new method is proposed to implement gain-scheduled controllers for nonlinear plants. Given a family of linear feedback controllers designed for linearizations of a nonlinear plant about constant operating points, a nonlinear gain-scheduled controller is derived that preserves the input-output properties of the linear closed loop systems locally, about each equilibrium point. The key procedures in the proposed method are to provide integral action at the inputs to the plant and differentiate some of the measured outputs before they are fed back to the scheduled controller. For a fairly general class of systems, the nonlinear gain-scheduled controllers are easy to obtain, and their structure is similar to that of the original linear controllers.Research Initiation Grant of the Naval Postgraduate SchoolNSF under Grant ECS-9096109AFOSR under Grant F49620-93-1-0246AR under Grant DAAH01-93-G-001

Bernstein Polynomial-Based Method for Solving Optimal Trajectory Generation Problems

The article of record as published may be found at http://dx.doi.org/10.3390/s22051869This paper presents a method for the generation of trajectories for autonomous system operations. The proposed method is based on the use of Bernstein polynomial approximations to transcribe infinite dimensional optimization problems into nonlinear programming problems. These, in turn, can be solved using off-the-shelf optimization solvers. The main motivation for this approach is that Bernstein polynomials possess favorable geometric properties and yield computationally efficient algorithms that enable a trajectory planner to efficiently evaluate and enforce constraints along the vehicles� trajectories, including maximum speed and angular rates as well as minimum distance between trajectories and between the vehicles and obstacles. By virtue of these properties and algorithms, feasibility and safety constraints typically imposed on autonomous vehicle operations can be enforced and guaranteed independently of the order of the polynomials. To support the use of the proposed method we introduce BeBOT (Bernstein/B�zier Optimal Trajectories), an open-source toolbox that implements the operations and algorithms for Bernstein polynomials. We show that BeBOT can be used to efficiently generate feasible and collision-free trajectories for single and multiple vehicles, and can be deployed for real-time safety critical applications in complex environments.This research was supported by the Office of Naval Research, grants N000141912106, N000142112091 and N0001419WX00155. Antonio Pascoal was supported by H2020-EU.1.2.2-FET Proactive RAMONES, under Grant GA 101017808 and LARSyS-FCT under Grant UIDB/50009/2020. Isaac Kaminer was supported by the Office of Naval Research grant N0001421WX01974.This research was supported by the Office of Naval Research, grants N000141912106, N000142112091 and N0001419WX00155. Antonio Pascoal was supported by H2020-EU.1.2.2-FET Proactive RAMONES, under Grant GA 101017808 and LARSyS-FCT under Grant UIDB/50009/2020. Isaac Kaminer was supported by the Office of Naval Research grant N0001421WX01974

Mudanças institucionais e reestruturação na indústria brasileira de laticínios (1990-2000)

In the nineties, Brazil has experienced several public policies which have transformed the country economy. The dairy sector was affected, mainly by the market deregulation, the Mercosur implementation and, by the economical stabilization resulting from the "Plano Real". This article aims to identify the changes in the institutional environment that had affected the national dairy industry and evaluate its restructuration. The new institutional economy and Porter's five competitive forces framework are the theoretical basis of the present analysis. The results demonstrate that the changes in the institutional environment had provoked immediate alterations in the relations between agents, demanding a sector restructuration in order to face the external competitors. The price liberalization due to the market deregulation brings back the bargain and, negotiations become more intense from the producer up to the industry to come along with the external competitiveness. The economical stabilization contributes to an increase in the consumption, production and importation of dairy products.O Brasil experimentou na década de noventa várias políticas públicas que transformaram a economia do país. O setor de laticínios foi afetado, principalmente, com a desregulamentação do mercado, a implantação do Mercosul e a estabilização econômica resultante do “Plano Real”. Neste artigo, objetiva-se identificar as mudanças no ambiente institucional que afetaram a indústria nacional de laticínios e avaliar a sua reestruturação. A nova economia institucional e o modelo das cinco forças competitivas de Porter servem de base teórica na análise. Os resultados mostram que as mudanças no ambiente institucional provocam, de imediato, alterações nas relações entre os agentes, exigindo uma reestruturação do setor a fim de enfrentar os concorrentes externos. Com a liberalização de preços pela desregulamentação ressurge a barganha e as negociações são mais intensas; e a produtividade aumenta, desde o produtor até a indústria, para acompanhar a concorrência externa. A estabilização econômica contribuiu para aumentos no consumo, na produção e nas importações de laticínios

Preparing a change laboratory intervention: waste management in a University hospital

Abstract: Researchers, interventionists and managers are challenged to plan an intervention for the development of an activity. To this purpose, it is necessary to understand and negotiate the object of the intervention with the participants. This task can be facilitated through the elaboration of a research scheme used as a planning and learning tool among interventionists and participants. This article presented an outline of such scheme for future application of a Change Laboratory (CL). This lab is considered a method to provide the development of the solid waste management activity in a university hospital in Paraná State, Brazil. The study shows the aspects to be explored to plan a CL in order to develop a new concept of this activity. It is a draft for the planning of these methodology sessions. Its preparation makes use of preliminary ethnographic data collected during the beginning of the investigative procedure foreseen by CL, seeking the current conflict historical understanding. Keywords: Activity Theory. Change Laboratory. Waste Management. University Hospital.   Preparando uma intervenção do Laboratório de Mudança:  a gestão dos resíduos de um hospital universitário   Resumo: Pesquisadores, intervencionistas e gestores são desafiados a planejar uma intervenção visando ao desenvolvimento de uma atividade. Para tanto, faz-se necessário entender e negociar o objeto da intervenção com os participantes. Tal tarefa pode ser facilitada por meio da elaboração de um esquema usado como instrumento de planejamento e aprendizagem entre intervencionista e participantes. Neste artigo apresentou-se um esboço deste esquema para a aplicação futura de um Laboratório de Mudança (LM). Este laboratório é considerado um método para propiciar o desenvolvimento da atividade de gestão de resíduos sólidos em um hospital universitário do Paraná. O estudo mostra os aspectos a serem explorados para planejar um LM visando desenvolver um novo conceito dessa atividade. Trata-se de um rascunho para o planejamento das sessões dessa metodologia. Sua elaboração faz uso de dados etnográficos preliminares coletados durante o início do processo investigativo previsto pelo LM, buscando a compreensão histórica da atual situação do conflito. Palavras-chave: Teoria da Atividade. Laboratório de Mudança. Gestão de Resíduos. Hospital Universitário