4,171 research outputs found

    A shortest-path based clustering algorithm for joint human-machine analysis of complex datasets

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    Clustering is a technique for the analysis of datasets obtained by empirical studies in several disciplines with a major application for biomedical research. Essentially, clustering algorithms are executed by machines aiming at finding groups of related points in a dataset. However, the result of grouping depends on both metrics for point-to-point similarity and rules for point-to-group association. Indeed, non-appropriate metrics and rules can lead to undesirable clustering artifacts. This is especially relevant for datasets, where groups with heterogeneous structures co-exist. In this work, we propose an algorithm that achieves clustering by exploring the paths between points. This allows both, to evaluate the properties of the path (such as gaps, density variations, etc.), and expressing the preference for certain paths. Moreover, our algorithm supports the integration of existing knowledge about admissible and non-admissible clusters by training a path classifier. We demonstrate the accuracy of the proposed method on challenging datasets including points from synthetic shapes in publicly available benchmarks and microscopy data

    Punitive Damages and the Intoxicated Driver: An Approach to Taylor v. Superior Court

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    This Note examines the applicability of punitive damages to California cases involving intoxicated drivers. Particular attention is paid to the concept of malice as required for the allowance of punitive awards under California Civil Code section 3294, and the adoption of an alternative standard for defining malice under the statute is suggested. The Note concludes that as a matter of public policy, and as a means of deterring intoxicated drivers, punitive damages should be allowed when the facts of a case demonstrate a conscious disregard on the part of the defendant for the safety of others

    Electrolytic Nickel Impregnation of Porous Anodic Aluminum Oxide Films Using AC Voltage as Solar Selective Absorber

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    AbstractAnodized aluminum oxide films on aluminum substrates 1050 (99.5% Al) was impregnated with nickel by electrodeposition technique. In these paper, we report the synthesis of Ni using the galvanostat mode, and also some experimental modification in the frequency and voltage values, in order to optimize the amount content of Ni on aluminum substrate The data values of the total reflectance were analyzed in the visible solar spectrum and near infrared as a function of voltage, frequency and time of the impregnation process. Several experiments were performed in order to correlate these parameters with the nickel content in the bottom of the pores of the film and its reflectance properties. By morphological analysis found that samples with average nickel content of 10% of the total pore volume not exhibit good properties of a selective absorber, however the samples containing 60% of the total pore volume, present in the reflectance spectrum visible solar 5% and 90% in the infrared solar spectrum so it can be considered a good selective absorber films makes these coatings are prospects for implementation in solar collectors

    “Incidencia politica de organizaciones sociales autogestivas.” Un analisis sobre el entramado de cooperativas y el movimiento cartonero

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    Anais das IV Jornadas Internacionais de Problemas Latino-Americanos: Lutas, Experiências e Debates na América Latina - ISBN 978-950-793-223-6 - Orgs. Paulo Renato da Silva ; Mario Ayala ; Fabricio Pereira da Silva ; Fernando José MartinsPresentamos un avance de la investigación enmarcada en el proyecto UBACyT sobre Estudio comparativo de la acción cultural de los movimientos populares urbanos en el AMBA. Somos universitarios y pertenecemos a una organización social de la Ciudad de Buenos Aires, que hace aproximadamente cinco años viene desarrollando diferentes proyectos de investiga- cion/acción participativa con cooperativas de cartoneros. Uno de los objetivos específicos de este investigación es estudiar las formas de incidencia política y cultural generadas por las organizaciones y el incipiente movimiento cartonero. Miles de personas excluidas pasaron de realizar una tarea individual y competitiva, a ser parte de or- ganizaciones sociales autogestivas. La propuesta es reflexionar sobre las vinculaciones entre estas organizaciones, el Estado y un sector tradicional del sindicalismo argentino (la Asociación de Trabajadores del Estado- ATE). La importancia de observar la interacción entre estas múltiples dimensiones y actores radica en que son constitutivos de las acciones colectivas que conforman los cimientos de este germinal movimiento cartonero. La estrategia para llevar adelante este proyecto se basó en el análisis, análisis de docu- mentos y entrevistas a referentes políticos de las tres cooperativas más importantes. Seleccio- namos estas cooperativas por la cantidad de miembros, por la incidencia en la agenda del mo- vimiento cartonero y en las políticas públicas que el Gobierno de la Ciudad de Buenos Aires iene hacia el sector. Nos referimos al Amanecer de los Cartoneros-MTE, Las Madreselvas y Recuperadores Urbanos del Oeste. En estas organizaciones, el trabajo fue, y es, el eje organizador de este nuevo movimiento social que llegó para quedarse.PPG – IELA – UNIL

    Investigating Diversity in the Banking Sector in Europe: The Performance and Role of Savings Banks. CEPS Paperbacks. June 2009

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    In the aftermath of the financial crisis, the foundations of modern and innovative financial systems developed over decades have suffered serious damage. This has triggered massive state interventions and has led authorities to revamp the regulatory structures and frameworks. While many voices have called for a return to more traditional approaches to banking and finance, no one has argued the merits of diversity. This book investigates the merits of a diverse banking system with a special focus on the performance and role of savings banks in selected European countries where they are still prominent (Austria, Germany and Spain) and where they have progressively disappeared (Belgium and Italy). The theoretical and empirical arguments that are developed in this book tend to support the view that it is economically and socially beneficial to have ‘dual bottom-line’ institutions, such as savings banks. For those who accept this premise, it would suggest that policy-makers should not take or support actions that could jeopardise this valuable element of the financial system in various countries in Europe and of the emerging integrated European financial system

    Radio observations of evaporating objects in the Cygnus OB2 region

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    We present observations of the Cygnus OB2 region obtained with the Giant Metrewave Radio Telescope (GMRT) at frequencies of 325 and 610 MHz. In this contribution we focus on the study of proplyd-like objects (also known as free-floating evaporating gas globules or frEGGs) that typically show an extended cometary morphology. We identify eight objects previously studied at other wavelengths and derive their physical properties by obtaining their optical depth at radio-wavelengths. Using their geometry and the photoionization rate needed to produce their radio-continuum emission, we find that these sources are possibly ionized by a contribution of the stars Cyg OB2 #9 and Cyg OB2 #22. Spectral index maps of the eight frEGGs were constructed, showing a flat spectrum in radio frequencies in general. We interpret these as produced by optically thin ionized gas, although it is possible that a combination of thermal emission, not necessarily optically thin, produced by a diffuse gas component and the instrument response (which detects more diffuse emission at low frequencies) can artificially generate negative spectral indices. In particular, for the case of the Tadpole we suggest that the observed emission is not of non-thermal origin despite the presence of regions with negative spectral indices in our maps.Fil: Isequilla, Natacha Laura. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Benaglia, Paula. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Ishwara Chandra, C. H.. National Center For Radio Astrophysics; IndiaFil: del Palacio, Santiago. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

    Air gap influence on the vibro-acoustic response of Solar Arrays during launch

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    One of the primary elements on the space missions is the electrical power subsystem, for which the critical component is the solar array. The behaviour of these elements during the ascent phase of the launch is critical for avoiding damages on the solar panels, which are the primary source of energy for the satellite in its final configuration. The vibro-acoustic response to the sound pressure depends on the solar array size, mass, stiffness and gap thickness. The stowed configuration of the solar array consists of a multiple system composed of structural elements and the air layers between panels. The effect of the air between panels on the behaviour of the system affects the frequency response of the system not only modifying the natural frequencies of the wings but also as interaction path between the wings of the array. The usual methods to analyze the vibro-acoustic response of structures are the FE and BE methods for the low frequency range and the SEA formulation for the high frequency range. The main issue in the latter method is, on one hand, selecting the appropriate subsystems, and, on the other, identifying the parameters of the energetic system: the internal and coupling loss factors. From the experimental point of view, the subsystems parameters can be identified by exciting each subsystem and measuring the energy of all the subsystems composing the Solar Array. Although theoretically possible, in practice it is difficult to apply loads on the air gaps. To analyse this situation, two different approaches can be studied depending on whether the air gaps between the panels are included explicitly in the problem or not. For a particular case of a solar array of three wings in stowed configuration both modelling philosophies are compared. This stowed configuration of a three wing solar arrays in stowed configuration has been tested in an acoustic chamber. The measured data on the solar wings allows, in general, determining the loss factors of the configuration. The paper presents a test description and measurements on the structure, in terms of the acceleration power spectral density. Finally, the performance of each modelling technique has been evaluated by comparison between simulations with experimental results on a spacecraft solar array and the influence on the apparent properties of the system in terms of the SEA loss factors has been analyse

    Enabling Identity for the IoT-as-a-Service Business Model

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    The IoT-as-a-Service (IoTaaS) business model has already been identified by some people from both industry and academia, but has not been formally defined. IoTaaS offers IoT devices on demand, with considerable cost savings and resource optimization. In addition, it enables different applications to reuse the existing devices. However, this business model is associated with different technological challenges that need to be addressed, one of which is the identity problem. Focusing on this, self-sovereign identity (SSI) schemes have proven to provide better privacy and scalability than traditional identity paradigms, which is especially important in the IoT owing to its characteristics. In this paper, we formally analyze an IoTaaS business model, identifying and detailing its main technological challenges. In addition, we tackle the identity problem of this business model and propose an SSI-based identity management system, which is compliant with the existing standards from the W3C, and include a performance evaluation.This work was supported in part by the Basque Country Government through the Collaborative Research Grants Program in Strategic Areas (ELKARTEK) Program by the Project TRUSTIND under Grant KK-2020/00054 and in part by the Spanish Government-Ministry of Science and Innovation through the Project AI4ES-2021 under Grant CER-20211030 and through the Project SICRAC under Grant PID2020-114495RB-I0
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