1,017 research outputs found

    Truncated Harmonic Osillator and Parasupersymmetric Quantum Mechanics

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    We discuss in detail the parasupersymmetric quantum mechanics of arbitrary order where the parasupersymmetry is between the normal bosons and those corresponding to the truncated harmonic oscillator. We show that even though the parasusy algebra is different from that of the usual parasusy quantum mechanics, still the consequences of the two are identical. We further show that the parasupersymmetric quantum mechanics of arbitrary order p can also be rewritten in terms of p supercharges (i.e. all of which obey Qi2=0Q_i^{2} = 0). However, the Hamiltonian cannot be expressed in a simple form in terms of the p supercharges except in a special case. A model of conformal parasupersymmetry is also discussed and it is shown that in this case, the p supercharges, the p conformal supercharges along with Hamiltonian H, conformal generator K and dilatation generator D form a closed algebra.Comment: 9 page

    AirCode: Unobtrusive Physical Tags for Digital Fabrication

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    We present AirCode, a technique that allows the user to tag physically fabricated objects with given information. An AirCode tag consists of a group of carefully designed air pockets placed beneath the object surface. These air pockets are easily produced during the fabrication process of the object, without any additional material or postprocessing. Meanwhile, the air pockets affect only the scattering light transport under the surface, and thus are hard to notice to our naked eyes. But, by using a computational imaging method, the tags become detectable. We present a tool that automates the design of air pockets for the user to encode information. AirCode system also allows the user to retrieve the information from captured images via a robust decoding algorithm. We demonstrate our tagging technique with applications for metadata embedding, robotic grasping, as well as conveying object affordances.Comment: ACM UIST 2017 Technical Paper

    ASASSN-14dq: A fast-declining type II-P Supernova in a low-luminosity host galaxy

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    Optical broadband (UBVRI) photometric and low-resolution spectroscopic observations of the type II-P supernova (SN) ASASSN-14dq are presented. ASASSN-14dq exploded in a low-luminosity/metallicity host galaxy UGC 11860, the signatures of which are present as weak iron lines in the photospheric phase spectra. The SN has a plateau duration of \sim\,90 d, with a plateau decline rate of 1.38 mag (100d)1\rm mag\ (100 d)^{-1} in V-band which is higher than most type II-P SNe. ASASSN-14dq is a luminous type II-P SN with a peak VV-band absolute magnitude of -17.7±\,\pm\,0.2 mag. The light curve of ASASSN-14dq indicates it to be a fast-declining type II-P SN, making it a transitional event between the type II-P and II-L SNe. The empirical relation between the steepness parameter and 56Ni\rm ^{56}Ni mass for type II SNe was rebuilt with the help of well-sampled light curves from the literature. A 56Ni\rm ^{56}Ni mass of \sim\,0.029 M_{\odot} was estimated for ASASSN-14dq, which is slightly lower than the expected 56Ni\rm ^{56}Ni mass for a luminous type II-P SN. Using analytical light curve modelling, a progenitor radius of 3.6×1013\rm \sim3.6\times10^{13} cm, an ejecta mass of 10 M\rm \sim10\ M_{\odot} and a total energy of 1.8×1051\rm \sim\,1.8\times 10^{51} ergs was estimated for this event. The photospheric velocity evolution of ASASSN-14dq resembles a type II-P SN, but the Balmer features (Hα\alpha and Hβ\beta) show relatively slow velocity evolution. The high-velocity Hα\alpha feature in the plateau phase, the asymmetric Hα\alpha emission line profile in the nebular phase and the inferred outburst parameters indicate an interaction of the SN ejecta with the circumstellar material (CSM).Comment: 28 pages, 29 figures, Accepted in MNRA

    Expandability, reversibility, and optimal capacity choice

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    We develop continuous-time models of capacity choice when demand fluctuates stochastically, and the firm's opportunities to expand or contract are limited. Specifically, we consider costs of investing or disinvesting that vary with time, or with the amount of capacity already installed. The firm's limited opportunities to expand or contract create call and put options on incremental units of capital; we show how the values of these options affect the firm's investment decisions.Research supported by the National Science Foundation and by the MIT Center for Energy and Environmental Policy Research

    The new option view of investment

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    This paper provides a simple introduction to the new option view of investment. We explain the shortcomings of the orthodox theory, and then outline the basic ideas behind the option framework. Several industry examples are briefly discussed.Supported by the MIT Center for Energy and Environmental Policy Research, and the U.S. Department of Energy. Supported by the National Science Foundation

    A SIMPLE AUTOMOTIVE APPLICATION USING FLEXRAY™ PROTOCOL

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    FlexRay™ protocol is emerging as the next generation automotive communication protocol which offers high data rate, deterministic, fault tolerant, flexible in-vehicle data communication. This protocol supports both time triggered and event triggered data communication. The network that uses FlexRay™ protocol is called FlexRay™ network. The need for FlexRay™ protocol is the substantial demand for the high capacity in-vehicle data communication between the electronic components. In this work, we used Infineon SoCs as FlexRay™ nodes and establish communication between multiple nodes using FlexRay™ protocol. A simple automotive application is developed with temperature and magnetic field sensor being connected to a node and the sensor data is being communicated over the FlexRay™ network

    Testudines of India: A Review on Diversity, Threats and Conservation Initiatives

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    The present review is a collection of the available literature resources related to Testudines of India. Different aspects of diversity studies pertaining to turtles in India is presented in this review along with threats and conservation initiatives in different parts of India in different timeline

    A markup interpretation of optimal rules for irreversible investment

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    We re-examine the basic investment problem of deciding when to incur a sunk cost to obtain a stochastically fluctuating benefit. The optimal investment rule satisfies a trade-off between a larger versus a later net benefit; we show that this trade-off is closely analogous to the standard trade-off for the pricing decision of a firm that faces a downward sloping demand curve. We reinterpret the optimal investment rule as a markup formula involving an elasticity that has exactly the same form as the formula for a firm's optimal markup of price over marginal cost. This is illustrated with several examples.Supported by the MIT Center for Energy and Environmental Policy Research, and by the National Science Foundation
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