Stabilization of trajectories for systems with nonholonomic constraints

A technique for stabilizing nonholonomic systems to trajectories is presented. It is well known that such systems cannot be stabilized to a point using smooth static-state feedback. The authors suggest the use of control laws for stabilizing a system about a trajectory, instead of a point. Given a nonlinear system and a desired nominal feasible trajectory, an explicit control law which will locally exponentially stabilize the system to the desired trajectory is given. The theory is applied to several examples, including a car-like robot

Stabilization of trajectories for systems with nonholonomic constraints

A technique for stabilizing nonholonomic systems to trajectories is presented. It is well known that such systems cannot be stabilized to a point using smooth static-state feedback. The authors suggest the use of control laws for stabilizing a system about a trajectory, instead of a point. Given a nonlinear system and a desired nominal feasible trajectory, an explicit control law which will locally exponentially stabilize the system to the desired trajectory is given. The theory is applied to several examples, including a car-like robot

Aspectos práticos e jurídicos relevantes do crowdfunding de investimento

TCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Jurídicas. Direito.Desde a crise de crédito de 2008, muitas empresas em seus estágios iniciais deixaram de existir por não conseguirem arrecadar recursos suficientes para desenvolver suas ideias e projetos. As formas de financiamento tradicionais, através de empréstimos bancários, fundos de investimento e investidores anjo, nem sempre estão disponíveis no mercado e, quando estão, seus operadores nem sempre estão dispostos a arriscarem investimentos em negócios que ainda não possuem resultados ou histórico de crédito. Dentro deste contexto, alinhando a ideia do poder da multidão com a existência dessa lacuna de alternativas no mercado para se poder obter financiamento, foi que surgiu o crowdfunding. Nesta senda, o objetivo deste trabalho é realizar uma análise sobre os aspectos práticos e jurídicos relevantes, em especial, do crowdfunding de investimentos, que se apresenta como modalidade de financiamento coletivo onde a empresa investida oferece, como contrapartida, a distribuição de valores mobiliários. Para tanto, valeu-se da técnica de pesquisa bibliográfica em fontes primárias e secundárias, como também de pesquisa qualitativa através da análise da norma específica, no caso, a Instrução CVM n. 588/2017 com a respectiva exposição de motivos, e pela observação do modus operandi adotado pelas plataformas eletrônicas. O intuito do estudo é averiguar como é intermediada a relação entre empresa investida e investidor, incluindo a análise dos instrumentos jurídicos adequados para formação dessa tríade a fim de que, ao final, estabeleça-se um parâmetro de verificação dos impactos da regulação neste mercado. Verificou-se ao longo do trabalho que o crowdfunding de investimento ainda é uma novidade para os brasileiros, como também para a doutrina, de modo que esta figura ainda carece de maiores investigações. Viu-se que a instrução normativa trazida pela CVM veio em boa hora, estabelecendo limites e condições importantes para funcionalidade deste mecanismo de funcionamento, buscando-se conciliar a necessidade de proteção do investidor, em face da assimetria de informações em relação a empresa investida, com a necessidade de tornar o mercado de crowdfunding viável, e não demasiadamente oneroso e complexo. Observou-se, também, a variedade de contrapartidas que as empresas podem oferecer ao investidor, o que resulta, por conseguinte, nos mais variados arranjos jurídicos contratuais possíveis para moldar a vontade das partes. Percebeu-se que os contratos de investimento podem ser complexos ou não, dependendo do objetivo das partes, não existindo ainda um padrão ou modelo contratual nacional praticado entre as plataformas. Por fim, concluiu-se, que ainda há a necessidade de refinamento doutrinário e de pesquisa no Brasil sobre o tema; de modo que hoje já há uma regulamentação sólida a seu respeito, a qual trouxe segurança jurídica para os personagens que têm interesse em participar dessa forma de distribuição de créditos e títulos, mas que ao longo dos próximos anos pode precisar ser alterada para se adaptar à realidade e maturidade deste mercado.Since the credit crunch of 2008, many early-stage companies have ceased to exist because they could not raise enough funds to develop their ideas and projects. Traditional forms of financing, for example, bank loans, investment funds, and angel investors are not always available in the market and when it is, they are not always willing to take risk investments in businesses that still do not have results. In this context, it was aligning the idea of the crowd’s efficiency with the existence of this gap of alternatives in the market to obtain financing, that the crowdfunding emerged. The goal of this work, therefore, is to perform an analysis on the relevant practical and legal aspects concerning the investment-based crowdfunding, which is presented as a financing modality where the invested company offers in return the distribution of securities to its investors. To address this, the study is based on the examination of research papers and articles, but mainly by the analysis on the regulation brought out by Brazil’s financial regulatory authority (CVM) through the “Regulation CVM n. 588/2017”, as well as by the observation of the modus operandi adopted by the crowdfunding platforms, in order to ascertain how the relationships between companies and investors are brokered, including the analysis of the legal instruments adopted by them. It has been found throughout the study that investment-based crowdfunding is still a novelty for the market, as well as for scholars, in a sense that it still lacks for further investigation. This research shows that the regulation brought out by CVM came in good time, establishing important limits and conditions for the crowdfunding’s functionality, and it was able to reconcile the need for investor protection, given the asymmetry of information with the invested company, and the need to make the crowdfunding market feasible, not turning it into a costly and complex mechanism. It was noted the variety of counterparties that companies can offer to investors, which can lead to varied contractual arrangements. Based on this knowledge, therefore, there is still a need for scholars to delve deeper into this subject in Brazil; specially because today there is sound regulation on this issue, which has given legal certainty to the characters who are interested in participating in this form of distribution of credits and securities, but which in the coming years may need to be modified to adapt to the forthcoming reality and maturity of this market

A randomized attitude slew planning algorithm for autonomous spacecraft

The ability to autonomously generate and execute large angle attitude maneuvers, while operating under a number of celestial and dynamical constraints, is a key factor in the development of several future space platforms. In this paper we propose a ran-domized attitude slew planning algorithm for autonomous spacecraft, which is able to address a variety of pointing constraints, including bright object avoidance and ground link maintenance, as well as constraints on the control inputs and spacecraft states, and integral constraints such as those deriving from thermal control requirements. Moreover, through the scheduling of feedback control policies, the algorithm provides a consistent decoupling between low-level control and attitude motion planning, and is robust with respect to uncertainties in the spacecraft dynamics and environmental disturbances. Sim-ulation examples are presented and discussed

Newly diagnosed rheumatic heart disease among indigenous populations in the Pacific

Objectives Rheumatic heart disease (RHD) remains the leading acquired heart disease in the young worldwide. We aimed at assessing outcomes and influencing factors in the contemporary era. Methods Hospital-based cohort in a high-income island nation where RHD remains endemic and the population is captive. All patients admitted with newly diagnosed RHD according to World Heart Federation echocardiographic criteria were enrolled (2005–2013). The incidence of major cardiovascular events (MACEs) including heart failure, peripheral embolism, stroke, heart valve intervention and cardiovascular death was calculated, and their determinants identified. Results Of the 396 patients, 43.9% were male with median age 18 years (IQR 10–40)). 127 (32.1%) patients presented with mild, 131 (33.1%) with moderate and 138 (34.8%) with severe heart valve disease. 205 (51.8%) had features of acute rheumatic fever. 106 (26.8%) presented with at least one MACE. Among the remaining 290 patients, after a median follow-up period of 4.08 (95% CI 1.84 to 6.84) years, 7 patients (2.4%) died and 62 (21.4%) had a first MACE. The annual incidence of first MACE and of heart failure were 59.05‰ (95% CI 44.35 to 73.75) and 29.06‰ (95% CI 19.29 to 38.82), respectively. The severity of RHD at diagnosis (moderate vs mild HR 3.39 (0.95 to 12.12); severe vs mild RHD HR 10.81 (3.11 to 37.62), p<0.001) and ongoing secondary prophylaxis at follow-up (HR 0.27 (0.12 to 0.63), p=0.01) were the two most influential factors associated with MACE. Conclusions Newly diagnosed RHD is associated with poor outcomes, mainly in patients with moderate or severe valve disease and no secondary prophylaxis