3,106 research outputs found
Space-Time Curvature Signatures in Bose-Einstein Condensates
We derive a generalized Gross-Pitaevski (GP) equation immersed on a
electromagnetic and a weak gravitational field starting from the covariant
Complex Klein-Gordon field in a curved space-time. We compare it with the GP
equation where the gravitational field is added by hand as an external
potential. We show that there is a small difference of order between
them that could be measured in the future using Bose-Einstein Condensates
(BEC). This represents the next order correction to the Newtonian gravity in a
curved space-time.Comment: 4 pages, no figure
The effects of structural reforms on employment outcomes in Portugal: a short-term analysis
This paper evaluates the short-term effects of both product and labour market reforms on employment growth. Using Portuguese firm-level data, covering the period 2006-2015, we show that product market deregulation brings employment gains. Concerning the labour market, while expenditure in active labour market policies and reductions of the tax wedge are also associated with positive employment developments, reforms targeted at lowering employment protection are associated with lower employment growth, at least during the short-term
Selection of portfolios of electricity generation projects : an exploratory study
The electricity planning traditionally relies on optimization models with the objective of minimizing system costs. However, the liberalization trend of the market and development of renewable energy increased the complexity of this planning exercise. It becomes then necessary to study other methodologies in order to include in the planning process the risk variables and potential correlation between technologies and fuels. The main guidelines of current energy policy in Portugal should meet the goals of energy efficiency, reduce energy dependence without compromising security of supply, minimizing the environmental impact and promoting renewable energy development. In a scenario of high growth of renewable energy sources (RES), it is pertinent to study the seasonality of electricity production by the various RES (biomass, hydro, wind, solar ...) evaluating the potential complementarily between these sources as a mitigation or increase risk factor. As for thermal power plants, the existence or not of correlation between fossil fuel prices must also be considered. The risk-return approach is often used in the selection of financial assets, however, several studies have revealed its potential when applied to electricity planning, especially with regard to the inclusion of RES projects. This study will test the possible application this model for the Portuguese electricity system, resulting in the proposal of future scenarios for the electricity generation sector taking into account the increasing importance of RES
Proibicionismo e segregação: uma análise pela perspectiva do interacionismo simbólico
Este artigo qualitativo-descritivo tem como objetivo evidenciar fenômenos de criação de regras e, subsequentemente, a figura do desviante. Através de pesquisa bibliográfica, serão analisados os marcos da história do proibicionismo pelas lentes do interacionismo simbólico, de modo a confirmar a hipótese de que o discurso proibicionista funciona como instrumento de manutenção da segregação
Statistical Complexity Analysis of Turing Machine tapes with Fixed Algorithmic Complexity Using the Best-Order Markov Model
Sources that generate symbolic sequences with algorithmic nature may differ in statistical complexity because they create structures that follow algorithmic schemes, rather than generating symbols from a probabilistic function assuming independence. In the case of Turing machines, this means that machines with the same algorithmic complexity can create tapes with different statistical complexity. In this paper, we use a compression-based approach to measure global and local statistical complexity of specific Turing machine tapes with the same number of states and alphabet. Both measures are estimated using the best-order Markov model. For the global measure, we use the Normalized Compression (NC), while, for the local measures, we define and use normal and dynamic complexity profiles to quantify and localize lower and higher regions of statistical complexity. We assessed the validity of our methodology on synthetic and real genomic data showing that it is tolerant to increasing rates of editions and block permutations. Regarding the analysis of the tapes, we localize patterns of higher statistical complexity in two regions, for a different number of machine states. We show that these patterns are generated by a decrease of the tape's amplitude, given the setting of small rule cycles. Additionally, we performed a comparison with a measure that uses both algorithmic and statistical approaches (BDM) for analysis of the tapes. Naturally, BDM is efficient given the algorithmic nature of the tapes. However, for a higher number of states, BDM is progressively approximated by our methodology. Finally, we provide a simple algorithm to increase the statistical complexity of a Turing machine tape while retaining the same algorithmic complexity. We supply a publicly available implementation of the algorithm in C++ language under the GPLv3 license. All results can be reproduced in full with scripts provided at the repository.Peer reviewe
Tecnologia e desenvolvimento: estudando as relações
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Sócio-Econômico, Programa de Pós-Graduação em Economia, Florianópolis, 2015.Desenvolvimento econômico e tecnologia possuem uma relação direta, de importância central nas ciências econômicas. A dissertação tem como objetivo estudar essa relação do ponto de vista teórico, utilizando o referencial da teoria do gap tecnológico, e corroborar o seu conteúdo através de um estudo empírico baseado em Fagerberg e Shrolec (2008). Os resultados reforçam a importância das capacidades tecnológicas e sociais, assim como das instituições e da educação básica para o desenvolvimento econômico. Esses resultados vão de encontro ao que é apresentado pela economia evolucionária, institucionalista, dos sistemas nacionais de inovação e dos paradigmas tecno-econômicos.Abstract : Economic development and technology have a direct relationship, with central importance in economics. The dissertation aims to study this relationship from a theoretical point of view, using the framework of the technological gap theory, and confirm its contents through an empirical study based on Fagerberg and Shrolec (2008). The results reinforce the importance of technological and social capabilities, as well as the institutions and basic education to economic development. These results relate to what is presented by evolutionary and institutionalist economics, national innovation systems and techno- economic paradigms theory
Reflexões sobre o regime de trabalho 12x36 na reforma trabalhista
O trabalho tem por finalidade realizar uma reflexão sobre a inclusão do artigo 59-A na CLT, pela Lei nº 13.467/2017 (Reforma Trabalhista), que estabelece o regime de trabalho 12x36 para qualquer atividade e podendo ser inclusive estabelecida por simples acordo individual. A fim de estabelecer bases sobre o tema foi analisado o instituto da jornada de trabalho, sua criação e evolução, para então ser estudado o regime 12x36. No que diz respeito especificamente ao regime de trabalho 12x36 foi feita a análise do artigo 59-A da CLT de onde se extrairam alguns elementos que foram trabalhados de forma mais ampla, como, por exemplo, a possibilidade de estabelecimento do referido regime por acordo individual e a configuração de salário complessivo pela previsão do parágrafo primeiro. A análise chegou no TST com o estudo sobre a Súmula nº 444 e posteriormente chegou ao STF com o exame da ADI nº 4.842/DF. Foi realizada pesquisa confrontando o citado regime12x36 com o direito ao descanso e o direito à saúde e sua possível ligação com a ocorrência de acidentes de trabalho. O que se observou é que o regime 12x36 apresenta problemas por gerar fadiga excessiva aos trabalhadores, podendo potencializar o risco de ocorrência de acidentes de trabalho. Ademais, o artigo 59-A da CLT não dialoga com as demais previsões legais e constitucionais, como por exemplo a ausência de observância do pagamento a maior das horas trabalhadas em horário noturno; bem como por confrontar a jurisprudência trabalhista (Súmula nº 91 do TST) pois possibilita a ocorrência de salário complessivo, o que é considerado nulo pelo TST.The goal of this work is to reflect about the inclusion of Article 59-A in the CLT, by Law 13.467 (Labor Reform), which establishes the 12x36 labor day for any work area, and may even be established by simple individual agreement. In order to settle the bases about the subject, the institute of jornada was analyzed, their creation and evolution, for then to be studied the 12x36 labor day. About the 12x36 labor day, it was analyzed the article 59-A, from where it was extracted some elements that was studied in a extensively way, such as the possibility of establishing this journey by individual agreement and the occurrence of salary compliant with the provisions of the first paragraph. The analysis arrived in the TST with the study on the Precedent nº 444 and later it went to the STF with the examination of ADI 4.842 / DF. A research was conducted comparing the 12x36 labor day with the right to rest and the right to health and its possible connection with the occurrence of work accidents. What was observed it was that the 12x36 labor day presents some presents problems because it causes excessive fatigue to the laborer, so can increase the occurrence of occupational accidents. The article 59-A don‘t dialogues with other legal and constitutional provisions, such as the absence observance of the greater payment of hours worked in the evening. It also disagrees with the labor jurisprudence (Precedent nº 91 of the TST) because it allows the occurrence of compliant salary, which is considered null by the TST
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