Polymorphic phase boundary in piezoelectric oxides

The design of phase boundaries has now become a consolidated strategy to improve the functional properties of piezoelectric oxides because of the unique properties that may be obtained in their vicinity. In particular, polymorphic phase boundaries (PPBs) have attracted significant interest in recent years because they represent a significant breakthrough in terms of enhanced piezoelectric activity of lead-free piezoelectric oxides. PPBs are temperature-driven phase transitions where both intrinsic and extrinsic contributions maximize, thereby enhancing the macroscopic properties of piezoelectric materials. This tutorial discusses potassium–sodium–niobate-based systems as model materials to reveal some of the most relevant advances in the design of PPBs through compositional modifications. We focus on how PPBs can be modulated by engineered doping and also discuss the direct relation between PPBs and the enhancement of piezoelectric activity. Finally, we briefly describe the main experimental techniques for detecting PPBs.Postprint (author's final draft

Enhanced free space detection in multiple lanes based on single CNN with scene identification

Many systems for autonomous vehicles' navigation rely on lane detection. Traditional algorithms usually estimate only the position of the lanes on the road, but an autonomous control system may also need to know if a lane marking can be crossed or not, and what portion of space inside the lane is free from obstacles, to make safer control decisions. On the other hand, free space detection algorithms only detect navigable areas, without information about lanes. State-of-the-art algorithms use CNNs for both tasks, with significant consumption of computing resources. We propose a novel approach that estimates the free space inside each lane, with a single CNN. Additionally, adding only a small requirement concerning GPU RAM, we infer the road type, that will be useful for path planning. To achieve this result, we train a multi-task CNN. Then, we further elaborate the output of the network, to extract polygons that can be effectively used in navigation control. Finally, we provide a computationally efficient implementation, based on ROS, that can be executed in real time. Our code and trained models are available online.Comment: Will appear in the 2019 IEEE Intelligent Vehicles Symposium (IV 2019

Revisiones de la imagen de la mujer en el arte contemporáneo

La imagen artística es un poderoso factor en los procesos de creación de identidad. ¿Nos representamos como nos vemos o acaso nos reflejamos en nuestras representaciones? La redefinición de los roles femeninos de occidente ha dependido en gran medida del acceso de la mujer al mundo de la creación artística. La imagen de la figura femenina como elemento pasivo de la contemplación del artista masculino se ha mantenido durante una gran parte de nuestra Historia del Arte; los arquetipos sobre la madre, la santa o la arpía han predominado en un imaginario planteado siempre desde la mirada patriarcal. Las artistas han tenido que tomar por asalto su capacidad como creadoras de imágenes para ofrecer alternativas a estos iconos. Durante la segunda mitad del SXX numerosas artistas han planteado la deconstrucción de los esquemas heredados sobre la imagen de la mujer y han aportado nuevos discursos en la búsqueda de una nueva identidad. Esta comunicación ofrece una reflexión sobre estas consideraciones a partir de obras de diferentes artistas femeninas donde se evidencia esta “nueva” visión de la mujer en el Arte

Análisis de la relación entre la estrategia de diversificación y el desempeño de la empresa: el rol del ciclo económico

[EN] The relationship between corporate strategies and firm performance has been one of the key debates in the discipline of Strategic Management. There are studies that analyse the moderating role that certain variables may play in that relationship. These variables tend to refer to aspects within the firm or, at the very least, within the competitive environment in which a firm operates. Nevertheless, the empirical evidence on the part the general environment plays from an economic perspective is much less common, and focuses on large corporations and on periods of economic growth. Accordingly, using a panel of 1,828 Spanish manufacturing firms of different sizes, an analysis is conducted of the differences in Return On Assets (ROA), Growth in Sales (GS) and Labor Productivity (LP) between specialised firms, those with related diversification, and those with unrelated diversification, between 2002 and 2011, in which there was a period of growth alternated with another one of economic recession. Although some superiority is noted of related diversification and specialisation over unrelated diversification, the differences between strategies are less significant in periods of economic recession, and vary according to the dimension of performance considered. These results reveal the need to consider the economic cycle as a contingent factor that affects the impact corporate strategies have on firm performance.[ES] La relación entre las estrategias corporativas y el desempeño empresarial ha sido uno de los debates centrales en la disciplina de la dirección estratégica. Diversos estudios analizan el rol moderador que juegan diversas variables en esta relación. Dichas variables tienden a referirse a aspectos internos de la empresa o, si acaso, a aspectos del entorno competitivo en el que la empresa opera. Sin embargo, es más escasa la evidencia empírica sobre el rol que desempeña el entorno general y suele enfocarse en grandes empresas y en períodos de crecimiento económico. En consecuencia, utilizando un panel de 1.828 empresas manufactureras españolas de diferentes tamaños, se realiza un análisis de las diferencias de rentabilidad sobre activos, crecimiento de ventas y productividad laboral entre empresas especializadas, con diversificación relacionada y con diversificación no relacionada, entre los años 2002 y 2011, en los cuales hubo un período de crecimiento alternado con otro de recesión económica. Aunque se destaca cierta superioridad de la diversificación relacionada y la especialización sobre la diversificación no relacionada, las diferencias entre estrategias son menos significativas en los períodos de recesión económica y varían de acuerdo a la dimensión de desempeño considerada. Estos resultados revelan la necesidad de considerar el ciclo económico como un factor contingente que afecta el impacto que las estrategias corporativas tienen sobre el desempeño de la empresa.This paper has been supported by Project ECO2015-67434-R of Spanish Ministry of Economy and Competitiveness (Spain) and for the Excellent Research Group “Strategor” of URJC-Bank of Santander

The economic determinants of conditional conservatism.

We study the economic determinants of conditional conservatism. Consistent with prior literature, we find that contracting induces only conditional conservatism and litigation induces both conditional and unconditional conservatism. We extend prior evidence by Qiang (2007) by showing that taxation and regulation induce not only unconditional conservatism, but conditional conservatism as well. We show that in certain scenarios taxation and regulation create incentives to shift income from periods with high taxation pressure and high public scrutiny to periods with lower taxation pressure and lower public scrutiny. These income shifting strategies are implemented by recognising current economic losses that, given managerial incentives to report aggressively, would not have been recognized otherwise, or by delaying the recognition of current economic gains that would have been recognized had circumstances been different.Conservatism; Contracting; Taxation; Political costs; Litigation risk;

Accounting conservatism and corporate governance.

We predict that firms with stronger corporate governance will exhibit a higher degree of accounting conservatism. Governance level is assessed using a composite measure that incorporates several internal and external characteristics. Consistent with our prediction, strong governance firms show significantly higher levels of conditional accounting conservatism. Our tests take into account the endogenous nature of corporate governance, and the results are robust to the use of several measures of conservatism (market-based and nonmarket-based). Our evidence is consistent with the direction of causality flowing from governance to conservatism, and not vice versa, indicating that governance and conservatism are not substitutes. Finally, we study the impact of earnings discretion on the sensitivity of earnings to bad news across governance structures. We find that, on average, strong-governance firms appear to use discretionary accruals to inform investors about bad news in a timelier mannerConditional conservatism; Corporate governance; Managerial discretion;

Board of directors' characteristics and conditional accounting conservatism : Spanish evidence.

Using a sample of Spanish listed firms for the period 1997-2002 we find that firms where the CEO has low influence over the functioning of the board of directors show a greater degree of accounting conservatism. We measure the influence of the CEO over the board of directors using two aggregate indexes combining 6 (8) characteristics of the functioning of the board of directors and its monitoring committees: board size, proportion of non-executive directors, proportion of independent directors, whether the chairman of the board is an executive director, the number of board meetings, and the existence of an audit committee, a nomination/remuneration committee and an executive committee. We define conservatism as the asymmetric recognition speed of good and bad news in earnings, and we measure it following Basu (1997) and Ball and Shivakumar (2005). Our results are robust to alternative specifications and specific controls for investment opportunities and for the endogenous nature of corporate governance and earnings quality. Overall, our evidence shows that firms with strong boards use conservative accounting numbers as a governance tool, even in an institutional setting with low litigation risk such as SpainConservatism; Governance; CEO; Board of Directors; Earnings Timeliness; Spain;