Fatores que afetam a adoção de análises de Big Data em empresas

With the total quantity of data doubling every two years, the low price of computing and data storage, make Big Data analytics (BDA) adoption desirable for companies, as a tool to get competitive advantage. Given the availability of free software, why have some companies failed to adopt these techniques? To answer this question, we extend the unified theory of technology adoption and use of technology model (UTAUT) adapted for the BDA context, adding two variables: resistance to use and perceived risk. We used the level of implementation of these techniques to divide companies into users and non-users of BDA. The structural models were evaluated by partial least squares (PLS). The results show the importance of good infrastructure exceeds the difficulties companies face in implementing it. While companies planning to use Big Data expect strong results, current users are more skeptical about its performance.Con la cantidad total de datos duplicándose cada dos años, el bajo precio de la informática y del almacenamiento de datos, la adopción del análisis Big Data (BDA) es altamente deseable para las empresas, como un instrumento para conseguir una ventaja competitiva. Dada la disponibilidad de software libre, ¿por qué algunas empresas no han adoptado estas técnicas? Para responder a esta pregunta, ampliamos la teoría unificada de la adopción y uso de tecnología (UTAUT) adaptado para el contexto BDA, agregando dos variables: resistencia al uso y riesgo percibido. Utilizamos el grado de implantación de estas técnicas para dividir las empresas entre: usuarias y no usuarias de BDA. Los modelos estructurales fueron evaluados con partial least squres (PLS). Los resultados muestran que la importancia de una buena infraestructura excede las dificultades que enfrentan las empresas para implementarla. Mientras que las compañías que planean usar BDA esperan muy buenos resultados, las usuarias actuales son más escépticos sobre su rendimiento.Com a quantidade total de dados duplicando a cada dois anos, o baixo preço da computação e do armazenamento de dados tornam a adoção de análises de Big Data (BDA) desejável para as empresas, como aquelas que obterão uma vantagem competitiva. Dada a disponibilidade de software livre, por que algumas empresas não adotaram essas técnicas? Para responder a essa pergunta, estendemos a teoria unificada de adoção e uso de tecnologia (UTAUT) adaptado para o contexto do BDA, adicionando duas variáveis: resistência ao uso e risco percebido. Usamos a nível da implementação da tecnologia para dividir as empresas em usuários e não usuários de técnicas de BDA. Os modelos estruturais foram avaliados por partial least squares (PLS). Os resultados mostram que a importância de uma boa infraestrutura excede as dificuldades que as empresas enfrentam para implementá-la. Enquanto as empresas que planejam usar Big Data esperam resultados fortes, os usuários atuais são mais céticos em relação ao seu desempenho

Quantum Polarization of D4-branes

The low energy effective field theory of type II D4-branes coupled to bulk supergravity fields is used to investigate {\it quantum} effects for D4-branes in the D0 supergravity background. Classically, the D4-branes are unaffected by this background. However, quantum (one-loop) effects are argued to lead to an induced density of D0-brane charge; e.g., D0-multipole moments on the D4-brane. The effect is divergent in field theory, but is expected to be cut-off naturally by stringy corrections.Comment: 15 pages, Some changes in the implications for string theory after discussions with Friedel Eppl

Living rough

Viure a la intempèrie ha estat, des de sempre, una de les expressions més acabades i completes de la misèria. Els desplaçats per les guerres o la fam, els refugiats polítics i els emigrants econòmics que marxen a la recerca d ' un lloc on poder radicar un projecte vital que els ofereixi unes mínimes possibilitats de supervivencia o millora personal, constitueixen la immensa majoria de la gent sense sostre. Una anàlisi detallada i extensa d'aquesta crua realitat conforma aquest article.Vivir a la intemperie ha sido, desde siempre, una de las expresiones más acabadas y completas de la miseria. Los desplazados por las guerras o el hambre, los refugiados políticos y los emigrantes económicos que marchan a la búsqueda de un lugar donde poder radicar un proyecto vital que les ofrezca unas mínimas posibilidades de supervivencia o mejora personal, constituyen la inmensa mayoría de la gente sin techo. Un análisis detallado y extenso de esta cruda realidad conforma este artículo.Living out in the weather has always been one of the lowest and most complete expressions of poverty. People displaced by war or hunger, political refugees and economic emigrants who leave in search of a place where they can make a life for themselves, which would give them the minimum possibilities of survival or personal improvement, constitute the vast majority of homeless people. This article is an extensive, detailed analysis of this crude reality

Minimal-time bioremediation of natural water resources

We study minimal time strategies for the treatment of pollution of large volumes, such as lakes or natural reservoirs, with the help of an autonomous bioreactor. The control consists in feeding the bioreactor from the resource, the clean output returning to the resource with the same flow rate. We first characterize the optimal policies among constant and feedback controls, under the assumption of a uniform concentration in the resource. In a second part, we study the influence of an inhomogeneity in the resource, considering two measurements points. With the help of the Maximum Principle, we show that the optimal control law is non-monotonic and terminates with a constant phase, contrary to the homogeneous case for which the optimal flow rate is decreasing with time. This study allows the decision makers to identify situations for which the benefit of using non-constant flow rates is significant

Predicting venous thromboembolic events in patients with cancer using a new machine learning paradigm

Treballs finals del Màster de Fonaments de Ciència de Dades, Facultat de matemàtiques, Universitat de Barcelona. Any: 2021. Tutor: Oriol Pujol Vila i José Manuel Soria[en] The rise of machine learning in the last decade has facilitated great advances in fields such as medicine, where very powerful models have been developed, capable of predicting certain medical conditions with an accuracy never seen before. The present work is focused on predicting one of the leading causes of death among patients with cancer: venous thromboembolic events (VTE). Over the years, several statistical models based on clinical/genetic data have been developed, and have made it possible to create some risk assessment tools, like the Khorana score [2]. However, none of them are based on machine learning. In this way, we propose a new model that uses advanced machine learning techniques and is able to outperform all models currently available. Furthermore, the model is based on a very recent and promising learning paradigm that has barely been tested, hence it is a great opportunity for us to explore and evaluate it. This breakthrough ultimately has an impact on the patient’s quality of life, improving the ability to detect patients at high risk of developing a VTE, who would benefit from preventive treatment

Impedance-compensated grid synchronisation for extending the stability range of weak grids with voltage source converters

This paper demonstrates how the range of stable power transfer in weak grids with voltage source converters (VSCs) can be extended by modifying the grid synchronisation mechanism of a conventional synchronous reference frame phase locked loop (PLL). By introducing an impedance-conditioning term in the PLL, the VSC control system can be virtually synchronised to a stronger point in the grid to counteract the instability effects caused by high grid impedance. To verify the effectiveness of the proposed approach, the maximum static power transfer capability and the small-signal stability range of a system with a VSC HVDC terminal connected to a weak grid are calculated from an analytical model with different levels of impedance-conditioning in the PLL. Such calculations are presented for two different configurations of the VSC control system, showing how both the static power transfer capability and the small-signal stability range can be significantly improved. The validity of the stability assessment is verified by time-domain simulations in the Matlab/Simulink environment.Peer ReviewedPostprint (published version