810 research outputs found

    Significados mĂşltiples y contradictorios del sobreendeudamiento : un estudio de caso de hogares en pobreza rural en Tamil Nadu

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    Con base en el estudio de caso de una zona rural en el sur de la India argumentamos que la definiciĂłn de sobreendeudamiento no puede restringirse a procesos de empobrecimiento material, puesto que las consecuencias de la deuda en tĂ©rminos de estatus social —los prestatarios valoran y clasifican las deudas de acuerdo con pĂ©rdidas de autorrespeto y dignidad— son de gran relevancia. El significado social de la deuda es tan importante como sus criterios financieros, depende de relaciones preexistentes entre deudores y prestamistas, y a su vez fortalece, preserva y en ocasiones reta ciertas posiciones preexistentes dentro de las jerarquĂ­as locale

    Trust in Collaborative Web Applications

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    Collaborative functionality is increasingly prevalent in web applications. Such functionality permits individuals to add - and sometimes modify - web content, often with minimal barriers to entry. Ideally, large bodies of knowledge can be amassed and shared in this manner. However, such software also provide a medium for nefarious persons to operate. By determining the extent to which participating content/agents can be trusted, one can identify useful contributions. In this work, we define the notion of trust for Collaborative Web Applications and survey the state-of-the-art for calculating, interpreting, and presenting trust values. Though techniques can be applied broadly, Wikipedia\u27s archetypal nature makes it a focal point for discussion

    Surgical Applications of Compliant Mechanisms:A Review

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    Current surgical devices are mostly rigid and are made of stiff materials, even though their predominant use is on soft and wet tissues. With the emergence of compliant mechanisms (CMs), surgical tools can be designed to be flexible and made using soft materials. CMs offer many advantages such as monolithic fabrication, high precision, no wear, no friction, and no need for lubrication. It is therefore beneficial to consolidate the developments in this field and point to challenges ahead. With this objective, in this article, we review the application of CMs to surgical interventions. The scope of the review covers five aspects that are important in the development of surgical devices: (i) conceptual design and synthesis, (ii) analysis, (iii) materials, (iv) maim facturing, and (v) actuation. Furthermore, the surgical applications of CMs are assessed by classification into five major groups, namely, (i) grasping and cutting, (ii) reachability and steerability, (iii) transmission, (iv) sensing, and (v) implants and deployable devices. The scope and prospects of surgical devices using CMs are also discussed

    Lorenz function of Bi2_{2}Te3_{3}/Sb2_{2}Te3_{3} superlattices

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    Combining first principles density functional theory and semi-classical Boltzmann transport, the anisotropic Lorenz function was studied for thermoelectric Bi2_{2}Te3_{3}/Sb2_{2}Te3_{3} superlattices and their bulk constituents. It was found that already for the bulk materials Bi2_{2}Te3_{3} and Sb2_{2}Te3_{3}, the Lorenz function is not a pellucid function on charge carrier concentration and temperature. For electron-doped Bi2_{2}Te3_{3}/Sb2_{2}Te3_{3} superlattices large oscillatory deviations for the Lorenz function from the metallic limit were found even at high charge carrier concentrations. The latter can be referred to quantum well effects, which occur at distinct superlattice periods

    A Monolithic Compliant Continuum Manipulator:A Proof-of-Concept Study

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    Continuum robots have the potential to form an effective interface between the patient and surgeon in minimally invasive procedures. Magnetic actuation has the potential for accurate catheter steering, reducing tissue trauma and decreasing radiation exposure. In this paper, a new design of a monolithic metallic compliant continuum manipulator is presented, with flexures for precise motion. Contactless actuation is achieved using time-varying magnetic fields generated by an array of electromagnetic coils. The motion of the manipulator under magnetic actuation for planar deflection is studied. The mean errors of the theoretical model compared to experiments over three designs are found to be 1.9 mm and 5.1degrees in estimating the in-plane position and orientation of the tip of the manipulator, respectively and 1.2 mm for the whole shape of the manipulator. Maneuverability of the manipulator is demonstrated by steering it along a path of known curvature and also through a gelatin phantom which is visualized in real time using ultrasound imaging, substantiating its application as a steerable surgical manipulator

    AS-CRED: Reputation and Alert Service for Inter-Domain Routing

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    Being the backbone routing system of the Internet, the operational aspect of the inter-domain routing is highly complex. Building a trustworthy ecosystem for inter-domain routing requires the proper maintenance of trust relationships among tens of thousands of peer IP domains called Autonomous Systems (ASes). ASes today implicitly trust any routing information received from other ASes as part of the Border Gateway Protocol (BGP) updates. Such blind trust is problematic given the dramatic rise in the number of anomalous updates being disseminated, which pose grave security consequences for the inter-domain routing operation. In this paper, we present ASCRED, an AS reputation and alert service that not only detects anomalous BGP updates, but also provides a quantitative view of AS’ tendencies to perpetrate anomalous behavior. AS-CRED focuses on detecting two types of anomalous updates (1)hijacked: updates where ASes announcing a prefix that they do not own; and (2) vacillating: updates that are part of a quick succession of announcements and withdrawals involving a specific prefix, rendering the information practically ineffective for routing. AS-CRED works by analyzing the past updates announced by ASes for the presence of these anomalies. Based on this analysis, it generates AS reputation values that provide an aggregate and quantitative view of the AS’ anomalous behavior history. The reputation values are then used in a tiered alert system for tracking any subsequent anomalous updates observed. Analyzing AS-CRED’s operation with real-world BGP traffic over six months, we demonstrate the effectiveness and improvement of the proposed approach over similar alert systems

    Enhancement of the thermoelectric figure of merit in a quantum dot due to the Coulomb blockade effect

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    We investigate the figure of merit of a quantum dot (QD) in the Coulomb blockade regime. It is found that the figure of merit ZTZT may be quite high if only single energy level in the QD is considered. On the other hand, with two or multi energy levels in the QD and without the Coulomb interaction, the ZTZT is strongly suppressed by the bipolar effect due to small level spacing. However, in the presence of the Coulomb interaction, the effective level spacing is enlarged and the bipolar effect is weakened, resulting in ZTZT to be considerably high. Thus, it is more likely to find a high efficient thermoelectric QDs with large Coulomb interaction. By using the parameters for a typical QD, the ZTZT can reach over 5.Comment: 6 pages, 4 figure

    Absorption spectrum of the HCCO radical

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    In the flash-photolysis of oxazole and isoxazole, new transient absorption bands are observed in the region 3080-3670Ă…. Vibrational analysis of these bands showed that they can be arranged into two electronic systems with their origin bands at 3333.60Ă… and 3367.01Ă…. Based on the experimental conditions under which the bands are produced and on the analysis of their vibrational and gross-rotational structure, these bands are assigned to a new carrier, the HCCO free radical

    Managed aquifer recharge in India: Consensual policy but controversial implementation

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    In the Indian water policy, Managed Aquifer Recharge (MAR) is considered as one of the best supply side water management options to face groundwater depletion. It is expected to optimize the resource as well as attain environmental sustainability and meet water demands and social justice. It is also expected to be implemented with a paradigmatic shift in water management. From policy to practices, at the local level, numerous recharge structures exist, are built or planned and reveal controversial implementation. With a sociohistorical approach, our paper analyses the trajectory of MAR implementation in the Pondicherry Region (South India). Through interviews and observations, the trajectories of two local projects are scrutinized, The Tank Rehabilitation Programs in Pondicherry district and a recharge shaft in Kiliyanur. Stakeholders' strategies and values regarding MAR are analysed and how local appropriation leads to adaptation and diversion. Finally, there is no paradigmatic shift going with MAR implementation. Instead, MAR is shown as a consensual policy because it is a possible compromise between groundwater conservation, optimization of the resource, satisfaction of the users and social justice, but controversial positions and oppositions should be acknowledged within implementation. The paper discusses opposed conceptions of MAR: participatory vs. expert driven, demand vs. supply driven and traditional vs. modern
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