Transport in quantum multi-barrier systems as random walks on a lattice

A quantum finite multi-barrier system, with a periodic potential, is considered and exact expressions for its plane wave amplitudes are obtained using the Transfer Matrix method [10]. This quantum model is then associated with a stochastic process of independent random walks on a lattice, by properly relating the wave amplitudes with the hopping probabilities of the particles moving on the lattice and with the injection rates from external particle reservoirs. Analytical and numerical results prove that the stationary density profile of the particle system overlaps with the quantum mass density profile of the stationary Schrodinger equation, when the parameters of the two models are suitably matched. The equivalence between the quantum model and a stochastic particle system would mainly be fruitful in a disordered setup. Indeed, we also show, here, that this connection, analytically proven to hold for periodic barriers, holds even when the width of the barriers and the distance between barriers are randomly chosen

Socializing the Semantic Gap: A Comparative Survey on Image Tag Assignment, Refinement and Retrieval

Where previous reviews on content-based image retrieval emphasize on what can be seen in an image to bridge the semantic gap, this survey considers what people tag about an image. A comprehensive treatise of three closely linked problems, i.e., image tag assignment, refinement, and tag-based image retrieval is presented. While existing works vary in terms of their targeted tasks and methodology, they rely on the key functionality of tag relevance, i.e. estimating the relevance of a specific tag with respect to the visual content of a given image and its social context. By analyzing what information a specific method exploits to construct its tag relevance function and how such information is exploited, this paper introduces a taxonomy to structure the growing literature, understand the ingredients of the main works, clarify their connections and difference, and recognize their merits and limitations. For a head-to-head comparison between the state-of-the-art, a new experimental protocol is presented, with training sets containing 10k, 100k and 1m images and an evaluation on three test sets, contributed by various research groups. Eleven representative works are implemented and evaluated. Putting all this together, the survey aims to provide an overview of the past and foster progress for the near future.Comment: to appear in ACM Computing Survey

Finding the extraordinary and creating the unexpected: Gnome and Genius combined in an entrepreneurial ethical heuristic

Purpose – This paper aims to present an integrated framework for ethical decision making in uncertain conditions, such as those of entrepreneurship. The model aims to build an exceptional ethical heuristic employable by entrepreneurs. Design/methodology/approach – The theoretical framework is anchored to Aquinas’ theory of practical reason virtue, specifically its minor virtue gnome, and the Kantian faculty of genius or to better say its modus operandi. Thanks to the composition of these prima facie distant ontologies it is possible to build a ‘ready-to-use’ heuristic. Findings – The paper through a philosophical discussion offers a ready-to-use heuristic that may help entrepreneurs and businesspersons when ‘navigating’ uncertain and troubled situations. In such situations, firstly it is important to recognize the ‘exceptionality’ of the situation, disregarding where necessary the ordinary criteria of judgment (an act directed by gnome). Secondly, a creative reconstruction of available knowledge able to re-shape the ‘rules of the game’ is needed (an act directed by PR but with connotations drawn from genius). Research limitations/implications – The paper provides only a theoretical conceptualization of the heuristic model. However, the result is a ready-to-use heuristic rule for entrepreneurs, who work in uncertain and unclear conditions. Empirical validation of the framework can represent an opportunity for future research to test the operative impact of such an exceptional ethical heuristic. Originality/value – Little attention has been dedicated to ethical decision making in the entrepreneurial setting built on a virtue ethics approach. This paper’s proposed model may represent an innovative alternative to strictly rational models for ethical decision making

The Graham Bank: hydrographic features and safety of navigation

To ensure safety of navigation, the monitoring of high-risk seabed areas is one of the primary tasks of the hydrographic activity. Monitoring of these areas also provides insights into environmental and scientific applications. The Graham Bank (Strait of Sicily in the Mediterranean Sea) has been monitored by the Italian Hydrographic Institute (IIM) for over a century. This article describes the IIM monitoring of the Graham Bank by conducting surveys using techniques and technologies available at each time and integrating all of the data into a modern bathymetric database. Based on the outcomes of this case study, the IIM proposes ways to minimize the risk to vessels passing close to the Graham Bank.Para garantizar la seguridad de la navegación, la supervisión de las zonas de los fondos marinos de alto riesgo es una de las tareas principales de la actividad hidrográfica. La supervisión de estas áreas también proporciona percepciones relativas a las aplicaciones ambientales y científicas. El Banco Graham (Estrecho de Sicilia en el mar Mediterráneo) ha sido supervisado por el Instituto Hidrográfico Italiano (IIM) durante más de un siglo. Este artículo describe la supervisión por parte del IIM del Banco Graham mediante la realización de levantamientos, utilizando las técnicas y tecnologías dispnibles en cada momento e integrando todos los datos en una base de datos batimétricos moderna. Basándose en los resultados de este estudio de caso, el IIM propone modos de minimizar el riesgo para los buques que pasan cerca del Banco Graham.Afin d'assurer la sécurité de la navigation, la surveillance des zones de fonds marins à haut risque est l'une des tâches principales de l'activité hydrographique. Surveiller ces zones permet également d'avoir un aperçu des enjeux environnementaux et scientifiques. Le Banc de Graham (Canal de Sicile, Mer Méditerranée) est surveillé par le Service hydrographique italien (IIM) depuis plus d'un siècle. Cet article décrit la surveillance du Banc de Graham par l'IIM qui s'appuie sur des levés effectués à l'aide des différentes techniques et technologies disponibles à chaque époque et sur l'intégration de toutes les données dans une base de données bathymétriques moderne. Sur la base des résultats de cette étude de cas, l'IIM propose des solutions afin de minimiser les risques pour des navires qui croisent à proximité du Banc de Graham

Characterization of honeys from west and south Buenos Aires province, Argentina

Pollen analyses were carried out on 33 honey samples from Espinal, Monte de Llanuras y Mesetas and Pampeana phytogeographical Provinces, collected during the 2000-2001 period. Sample processing as well as qualitative and quantitative analyses were performed according to standard techniques. Sixty-seven morphological pollen types were identified. The association of Eucalyptus sp. (E. camaldulensis Dehnh., E. viminalis Labill.), Centaurea sp. (C. solstitialis L., C. calcitrapa L.) and Diplotaxis tenuifolia DC. characterized these honeys. Twelve samples were unifloral: six from Eucalyptus sp., five from Helianthus annuus L., and one from Brassicaceae. Asteraceae and Fabaceae were the most representative botanical families

A Melissopalynological map of the south and southwest of the Buenos Aires province, Argentina

El objetivo de este trabajo fue elaborar un mapa melitopalinológico del sur y sudoeste de la provincia de Buenos Aires, Argentina, con datos de análisis polínicos de 127 muestras de miel provenientes de las eco-regiones Pampa, Distrito del Caldén en el Espinal, y Monte de Llanuras y Mesetas, recolectadas en el período 1992-2002. Utilizando análisis de componentes principales y de cluster, los partidos se agruparon en cinco regiones: I (Tres Arroyos, San Cayetano, Coronel Pringles y Coronel Dorrego), II (Guaminí, Saavedra, Coronel Suárez y Adolfo Alsina), III (Coronel Rosales, Monte Hermoso, Bahía Blanca y Villarino), IV (Patagones y Tornquist) y V (Puán). En las Regiones I, III y IV el 80% de las muestras fueron monoflorales. La Región I se caracterizó por la presencia de un 50% de mieles de Helianthus annuus y de un 10% de mieles de trébol; la Región III por 60% de mieles de Eucalyptus sp.; y la Región IV por 30% de mieles de Diplotaxis tenuifolia. En las Regiones II y V el 50% de las mieles fueron monoflorales: la Región II se distinguió por la presencia de 50% de mieles de H. annuus y la Región V por 15% de mieles de Larrea divaricata y 15% de mieles de Vicia sp. Las mieles multiflorales de la Región V se destacaron por la presencia de pólen de Condalia microphylla. La mayor diversidad de tipos polínicos correspondió a las familias Fabaceae y Asteraceae. La asociación de Eucalyptus sp., Centaurea sp. y Diplotaxis tenuifolia caracterizó a las mieles de las cinco regiones. La variabilidad natural de las muestras de miel hace muy difícil definir límites precisos entre las diferentes regiones.The aim of this work was to produce a melissopalynological map of the south and southwest of the Buenos Aires Province, Argentina, using pollen analysis data pertaining to 127 honey samples from the Pampa, Espinal (the Calden District), and Monte de Llanuras y Mesetas ecoregions, collected over the period 1992-2002. Using principal components and hierarchical cluster analysis, the different districts were grouped into five regions: I (Tres Arroyos, San Cayetano, Coronel Pringles and Coronel Dorrego), II (Guaminí, Saavedra, Coronel Suárez and Adolfo Alsina), III (Coronel Rosales, Monte Hermoso, Bahía Blanca and Villarino), IV (Patagones and Tornquist), and V (Puán). In Regions I, III and IV, 80% of honey samples were monofloral: Region I was characterized by the presence of 50% Helianthus annuus honeys and 10% clover honeys, Region III by 65% Eucalyptus sp. honeys, and Region IV by 30% Diplotaxis tenuifolia honeys. In Regions II and V, 50% of honeys were monofloral. Region II was distinguished by the presence of 50% H. annuus honeys, and Region V by 15% Larrea divaricata and 15% Vicia sp. honeys. The multifloral honeys of Region V included samples containing Condalia microphylla pollen. The families Fabaceae and Asteraceae provided the greatest diversity of pollen types. The association of Eucalyptus sp., Centaurea sp., and Diplotaxis tenuifolia characterised the honeys from all five regions. The natural variability of honey samples renders it very difficult to define the boundaries between the different regions

Reliability of My Jump 2 Derived from Crouching and Standing Observation Heights

The crouching or prone-on-the-ground observation heights suggested by the My Jump app are not practical in some settings, so users usually hold smartphones in a standing posture. This study aimed to analyze the reliability of My Jump 2 from the standardized and standing positions. Two identical smartphones recorded 195 countermovement jump executions from 39 active adult athletes at heights 30 and 90 cm, which were randomly assessed by three experienced observers. The between-observer reliability was high for both observation heights separately (ICC~0.99; SEM~0.6 cm; CV~1.3%) with low systematic (0.1 cm) and random (±1.7 cm) errors. The within-observer reliability for the three observers comparing the standardized and standing positions was high (ICC~0.99; SEM~0.7 cm; CV~1.4%), showing errors of 0.3 ± 1.9 cm. Observer 2 was the least accurate out of the three, although reliability remained similar to the levels of agreement found in the literature. The reliability of the mean observations in each height also revealed high reliability (ICC = 0.993; SEM = 0.51 cm; CV = 1.05%, error 0.32 ± 1.4 cm). Therefore, the reliability in the standing position did not change with respect to the standardized position, so it can be regarded as an alternative method to using My Jump 2 with practical added benefits.This research was funded by Generalitat Valenciana, grant number GV/2021/098

Deterministic reversible model of non-equilibrium phase transitions and stochastic counterpart

N point particles move within a billiard table made of two circular cavities connected by a straight channel. The usual billiard dynamics is modified so that it remains deterministic, phase space volumes preserving and time reversal invariant. Particles move in straight lines and are elastically reflected at the boundary of the table, as usual, but those in a channel that are moving away from a cavity invert their motion (rebound), if their number exceeds a given threshold T. When the geometrical parameters of the billiard table are fixed, this mechanism gives rise to non--equilibrium phase transitions in the large N limit: letting T/N decrease, the homogeneous particle distribution abruptly turns into a stationary inhomogeneous one. The equivalence with a modified Ehrenfest two urn model, motivated by the ergodicity of the billiard with no rebound, allows us to obtain analytical results that accurately describe the numerical billiard simulation results. Thus, a stochastic exactly solvable model that exhibits non-equilibrium phase transitions is also introduced

Concurrent Validity of the Inertial Measurement Unit Vmaxpro in Vertical Jump Estimation

The aim of this study was to evaluate if the inertial measurement unit (IMU) Vmaxpro is a valid device to estimate vertical jump height (VJH) when compared to a motion capture system (MoCAP). Thirteen highly trained female volleyball players participated in this study which consisted of three sessions. After a familiarization session, two sessions comprised a warm-up followed by ten countermovement jumps, resting two min between each attempt. Jump height was measured simultaneously by Vmaxpro using take-off velocity and MoCAP using center-of-mass vertical excursion. Results show significant differences in jump height between devices (10.52 cm; p < 0.001; ES = 0.9), a very strong Spearman’s correlation (rs = 0.84: p < 0.001), and a weak concordance correlation coefficient (CCC = 0.22; ρ = 0.861; Cb= 0.26). Regression analysis reveals very high correlations, high systematic error (8.46 cm), and a nonproportional random error (SEE = 1.67 cm). Bland–Altman plots show systematic error (10.6 cm) with 97.3 % of the data being within the LoA. In conclusion, Vmaxpro can be considered a valid device for the estimation of VJH, being a cheaper, portable, and manageable alternative to MoCAP. However, the magnitude of systematic error discourages its use where indistinguishable data from Vmaxpro and MoCAP are used unless the corresponding specific fitting equation is applied.This work was supported by Generalitat Valenciana (grant number GV/2021/098)