Endogenous Credit-card Acceptance in a Model of Precautionary Demand for Money

A credit-card acceptance decision by retailers is embedded into a simple model of precautionary demand for money. The model gives a new explanation for how the use of credit-cards can differ so widely across countries. Retailers' propensity to accept cards reduces the need for buyers to hold cash as the chance of a stock-out (of cash) is reduced. When retailers make their decision with respect to credit-card acceptance they do not take into account the effect that decision has on other sellers. This externality generates multiple equilibria over some portions of the parameter space.

Hybrid visual servoing with hierarchical task composition for aerial manipulation

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper a hybrid visual servoing with a hierarchical task-composition control framework is described for aerial manipulation, i.e. for the control of an aerial vehicle endowed with a robot arm. The proposed approach suitably combines into a unique hybrid-control framework the main benefits of both image-based and position-based control schemes. Moreover, the underactuation of the aerial vehicle has been explicitly taken into account in a general formulation, together with a dynamic smooth activation mechanism. Both simulation case studies and experiments are presented to demonstrate the performance of the proposed technique.Peer ReviewedPostprint (author's final draft

Investigation of the Micromechanics of the Microbond Test

The microbond test is a method which is sometimes used for measuring interfacial shear strength. In the analysis of the data it is often assumed that the interfacial shear stress is constant and thus, by implication, that the strain in the fibre along the embedded fibre decreases linearly from the point of entry to the point of exit. In this paper the results of conventional microbond tests and simulated microbond tests performed under a Raman microscope on a Kevlar-49/epoxy system are reported. The conventionally performed tests show that the calculated interfacial shear strength for this system is approximately 16 MPa regardless of the position of the supporting knife edges. The strain distribution along the fibre during simulated microbond tests was studied as a function of knife edge position, interfacial area and level of load by means of Raman spectroscopy. It was found that the interfacial shear stress was not constant, as is frequently assumed, but was strongly dependent upon distance through the droplet, knife-edge position and applied load. At low loads the strain was a maximum at the point where the fibre entered the droplet and then dropped off sharply through the embedded length. This effect was enhanced when the knife-edge separation was reduced. The variation of the shape of the stress distribution was similar to that predicted by a linear finite element analysis. At higher load levels the onset of failure in the region closest to the point where the fibre entered the droplet could be observed

A 3D serious game for dental learning in higher education

Natural User Interfaces and advanced displays can be combined to provide rich learning experiences. In this paper, we present the development and validation of a serious game that combines autostereoscopy and Natural User Interfaces for dental learning in higher education. The game includes two modes: neutral and real-world background. A comparative study to check different aspects was carried out. A total of 33 dentistry students participated in the study. From the results, the students increased significantly their knowledge about teeth morphology. Most of the students preferred the neutral background for dental learning. The real-world background was identified as being more suitable for leisure activities

Polynomial Time Cryptanalytic Extraction of Neural Network Models

Billions of dollars and countless GPU hours are currently spent on training Deep Neural Networks (DNNs) for a variety of tasks. Thus, it is essential to determine the difficulty of extracting all the parameters of such neural networks when given access to their black-box implementations. Many versions of this problem have been studied over the last 30 years, and the best current attack on ReLU-based deep neural networks was presented at Crypto 2020 by Carlini, Jagielski, and Mironov. It resembles a differential chosen plaintext attack on a cryptosystem, which has a secret key embedded in its black-box implementation and requires a polynomial number of queries but an exponential amount of time (as a function of the number of neurons). In this paper, we improve this attack by developing several new techniques that enable us to extract with arbitrarily high precision all the real-valued parameters of a ReLU-based DNN using a polynomial number of queries and a polynomial amount of time. We demonstrate its practical efficiency by applying it to a full-sized neural network for classifying the CIFAR10 dataset, which has 3072 inputs, 8 hidden layers with 256 neurons each, and over million neuronal parameters. An attack following the approach by Carlini et al. requires an exhaustive search over 2 to the power 256 possibilities. Our attack replaces this with our new techniques, which require only 30 minutes on a 256-core computer

Propiedades antioxidantes y anticancerígenas de la alcachofa (Cynara scolymus) sobre Caco-2

La investigación sobre el desarrollo y el tratamiento del cáncer está muy presente en la actualidad al tratarse de una de las enfermedades con mayor incidencia y tasa de mortalidad a nivel mundial, siendo el de colon el tercer tipo más común. Los tratamientos convencionales del cáncer, como la quimioterapia o la radioterapia, resultan eficaces, pero generan diversos efectos secundarios en el paciente. Por ello, se están investigando nuevas terapias alternativas y complementarias con sustancias naturales que sean menos agresivas, para así reducir o eliminar los efectos secundarios. Entre estas nuevas terapias destacan residuos de la industria alimentaria con potencial aplicación terapéutica por sus múltiples propiedades beneficiosas para el organismo. Por tanto, el objetivo de este Trabajo de Fin de Grado consistió en evaluar las propiedades antioxidantes, antiinflamatorias y anticancerígenas de dos fracciones de extractos de las hojas externas de la alcachofa (Cynara scolymus) sobre células del carcinoma de colon humano (Caco-2/TC7). Para evaluar su actividad antiinflamatoria se realizaron estudios de la desnaturalización de la albúmina sérica bovina; su capacidad antioxidante se determinó mediante el ensayo ABTS; y las propiedades anticancerígenas se evaluaron mediante la técnica SRB, citometría de flujo y medida de la producción de especies reactivas de oxígeno. Aunque ninguna de las fracciones posee propiedades antioxidantes ni antiinflamatorias, la Fracción 1 destacó por su potencial anticancerígeno. Si bien la Fracción 2 carecía de selectividad puesto que ocasionó la muerte de enterocitos sanos, la Fracción 1 causó la muerte no apoptótica de las células Caco-2 sin dañar las células no tumorales. En cuanto a su mecanismo de acción, se observó un efecto prooxidante relacionado con daños en la membrana mitocondrial de las células cancerígenas. Estos resultados permitieron concluir que los extractos de hojas externas de alcachofa podrían ser aplicados en quimioterapia

Flexible Bonding of the Phosph(V)azane Dianions [S(E)P(µ-NtBu)]22-

Oxidation of the P(III) dianion [S-P(µ-NtBu)]22- (1) with elemental sulphur, selenium and tellurium gives the P(V) dianions [(S)(E)P(µ-NtBu)]22- (E = S (6a), Se (6b), Te (6c)). Although 6c proves to be too unstable, the S,S-dianion 6a and ambidentate S,Se-dianion 6b are readily transferred intact to main group and transition metal elements, producing a range of new cage and coordination compounds. While their coordination characteristics are in many ways similar to closely-related isoelectronic phosph(V)azane anions [(E)(RN=)P(µ-NtBu)]22-, the sterically unhindered nature of 6 introduces an expanded range of coordination modes, i.e., facial S,S- and Se,Se-bonding as well as side-on S,Se-coordination. All of these bonding modes are observed for the amibidentate S,Se dianion 6b.We thank the EU (ERC Advanced Grant for DSW, Erasmus grant for AJP), Cambridge Australia Scholarships (FJR) and the Cambridge Trust (AJP, FJR) and the PPF (AJP) for funding and the Spanish MINECO-AEI and the European Union (ESF) for a Ramon y Cajal contract (RG-R, RYC-2015–19035)

El remedio parlamentario al fallo de la Corte en el caso Muiña

Tras la Sentencia dictada en el caso Muiña se extendió la idea de que la Corte Suprema había actuado de forma correcta al conceder el beneficio del cómputo de 2x1 a un condenado por delitos de lesa humanidad. Esta afirmación descansa en la creencia de que la consecuencia reprochable del fallo no se debió a un error de la Corte sino a una laguna del sistema normativo, la que fue subsanada por la ley N° 27362 dictada por el Congreso días después. El objetivo de este trabajo es mostrar que, contrariamente a esta opinión, el fallo no fue el resultado de un vacío legal sino de una interpretación incorrecta de las normas por parte de la Corte. Por tanto, la ley dictada por el Congreso no tuvo como objetivo suplir una laguna sino corregir este error mediante una interpretación auténtica del material normativo. Asimismo, se intenta mostrar que la interpretación restaurada por el Congreso es la correcta por ser la que mejor se adecua a nuestra historia institucional en materia de persecución y condena de delitos de lesa humanidad.After the judgment rendered in the ―Muiña‖ case, many considered that the Supreme Court had ruled properly by granting the ―2x1‖ calculation benefit to a person convicted for the commission of crimes against humanity. This statement was based on the idea that the undesirable outcome of the judgment did not result from a Court’s misinterpretation of the law but from a gap in the legal system, which was filled through an act passed by the Parliament in the following days. The aim of this paper is to show that, contrary to this widely held opinion, the Court misconstrued the law and, therefore, the purpose of the parliamentary act was not to fill a normative gap but to correct this mistake by an authentic interpretation of the legal rules. Moreover, this paper aims to show that the Parliament's interpretation is the correct one since it is the one that best meets our institutional history with regard to the persecution and conviction of crimes against humanity.Fil: Huais, María Valentina. Universidad Nacional de Córdoba. Facultad de Derecho y Ciencias Sociales. Centro de Investigaciones Juridícas y Sociales; ArgentinaFil: Rodrigez Nasuti, Florencia. Universidad Nacional de Córdoba. Facultad de Derecho y Ciencias Sociales. Centro de Investigaciones Juridícas y Sociales; ArgentinaFil: Seleme, Hugo Omar. Universidad Nacional de Córdoba. Facultad de Derecho y Ciencias Sociales. Centro de Investigaciones Juridícas y Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin