3,171 research outputs found

    On Scale Invariance and Anomalies in Quantum Mechanics

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    We re-consider the quantum mechanics of scale invariant potentials in two dimensions. The breaking of scale invariance by quantum effects is analyzed by the explicit evaluation of the phase shift and the self-adjoint extension method. We argue that the breaking of scale invariance reported in the literature for the δ\delta(r) potential, is an example of explicit and not an anomaly or quantum mechanical symmetry breaking.Comment: 15 pp in latex, no figure

    Analysis of integrated STATCOM-SMES based on three-phase three-level multi-pulse voltage source inverter for high power utility applications

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    This paper is aimed to investigate the operating characteristics of a static synchronous compensator (STATCOM) integrated with superconducting magnetic energy storage (SMES) for high power applications in the transmission network level. The STATCOM controller topology comprises multi-level multi-pulse neutral-point clamped-type (NPC) voltage source inverters (VSIs) using the harmonics cancellation technique, and incorporates a SMES coil. An innovative two-quadrant multi-level dcdc converter is proposed to effectively interface the STATCOM with the superconducting coil using a buck-boost topology with neutral point voltage control capabilities; thus enabling to simultaneously control both active and reactive power exchange with the high voltage power system. A detailed analysis of major system variables is presented, including analytical results and digital simulations using the MATLAB/Simulink environment. Moreover, a three-level control scheme is designed, including a full decoupled current control strategy in the dq reference frame with a novel controller to prevent the STATCOM dc bus capacitors voltage drift/imbalance and an enhanced power system frequency controller.Fil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Watanabe, Edson H.. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin

    Decision-Making About Volitional Impairment in Sexually Violent Predators

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    The Kansas v. Hendricks (1997) decision, in which the Supreme Court authorized post-sentence civil commitment for certain sex offenders, appeared to be constitutionally legitimized by limiting the class of offenders eligible for this special form of civil commitment to those who are “unable to control” their dangerousness. Nowhere in the available record, however, did the Court elucidate what they meant by this notion of volitional impairment. This study sought to examine factors that legal professionals (n = 43), psychologists (n = 40), and mock jurors (n = 76) deem most relevant to a determination of sex offender volitional impairment. Participants, who were randomly assigned to a sexual predator commitment or an insanity hearing context, read a series of 16 vignettes that described a pedophilic offender and included combinations of variables hypothesized to be related to judgments of volitional impairment. Results suggested that participants, who as a group made remarkably high estimates of likelihood of future sexual violence, considered verbalization of control, history of sexual violence, and the context of the hearing as highly relevant to determinations of volitional impairment. Implications for policy and practice are explored

    Correlacion de pares de imagenes para medicion de solidos por fenomenos estereo

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    [Correlation of pairs of images for measurement of solids by stereo phenomena] It is made a description of optical principles, which are used to obtain 3D information from 2D information. The main interest is focused, around the problems for the intelligent matching between segments of photographs, which are taken without constrains. The automation of such a matching task, is so useful in measuring solids, where the high accuracy, and also the avoidance of human aid are desirable. Solutions, which were proposed in the Industry and Mathematics Workshop, and procedures of public domain for editing photographs, are proposed as complementary

    Problemas directo e inverso para el abatimiento del manto freatico

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    [Direct and Inverse Problems for Lowering the water table

    Family Constitutions: A Case Study of Ten Families--Problems, Issues and Concerns

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    This paper looks at ten family constitutions crafted with the assistance of the Family Business Development Center (FBDC) within a span of at least two years. The families, all Filipinos, are in different industries, reside in various cities, and are in various stages of managerial transition between generations. The ten constitutions are analyzed from different relational and business angles, including governance structure, family communication, succession and retirement plan, professionalizing the business, strategic planning, ownership contract and business protocol. The paper proposes to undertake a comparative study of family constitutions in five ASEAN countries

    Effect of Speckle Filtering in the Performance of Segmentation of Ultrasound Images Using CNNs

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    The convolutional neural networks (CNNs) as tools for ultrasound image segmentation often have their performance affected by the low signal-to-noise ratio of the images. This prevents a correct classification and extraction of relevant information and therefore affects clinical diagnosis. We propose a study of the effect of different speckle filtering methods on CNN performance. For the proposed metrics (Jaccard coefficient and BF-Score), it was obtained that the SRAD filter exhibited the best behavior even in the lowest quality data. In addition, the lowest values were obtained for the standard deviation and variance, which translates into lower data dispersion, better repeatability, and, therefore, greater confidence in its accuracy. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG

    La sustentabilidad: el reto de nuestra generación

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    Invitación a analizar críticamente lo alcanzado a 25 años de la primera definición del término sustentabilidad, para distinguir los desafíos que tenemos enfrente. El desarrollo sustentable basado en la responsabilidad ambiental, la equidad social y la viabilidad económica está en contradicción con el desarrollo centrado en el crecimiento económico. Una de las razones que hacen imposible resolver esta contradicción es el hecho de que el paradigma tecno económico en que vivimos requiere del consumo para generar riqueza. El consumo es el motor que lo alimenta, y es también este híper consumo el que descarrila los esfuerzos por alcanzar una sustentabilidad profunda. Los retos a enfrentar tienen que ver con este dilema, e implican cambios profundos en los estilos de vida, los modelos de producción y de consumo, y las estructuras de poder que nos rigen
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