2,513 research outputs found

    Predictions of Dynamic Behavior Under Pressure for Two Scenarios to Explain Water Anomalies

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    Using Monte Carlo simulations and mean field calculations for a cell model of water we find a dynamic crossover in the orientational correlation time τ\tau from non-Arrhenius behavior at high temperatures to Arrhenius behavior at low temperatures. This dynamic crossover is independent of whether water at very low temperature is charaterized by a ``liquid-liquid critical point'' or by the ``singularity free'' scenario. We relate τ\tau to fluctuations of hydrogen bond network and show that the crossover found for τ\tau for both scenarios is a consequence of the sharp change in the average number of hydrogen bonds at the temperature of the specific heat maximum. We find that the effect of pressure on the dynamics is strikingly different in the two scenarios, offering a means to distinguish between them.Comment: 10 Pages, 4 figure

    Formal Verification of Safety Properties for Ownership Authentication Transfer Protocol

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    In ubiquitous computing devices, users tend to store some valuable information in their device. Even though the device can be borrowed by the other user temporarily, it is not safe for any user to borrow or lend the device as it may cause private data of the user to be public. To safeguard the user data and also to preserve user privacy we propose and model the technique of ownership authentication transfer. The user who is willing to sell the device has to transfer the ownership of the device under sale. Once the device is sold and the ownership has been transferred, the old owner will not be able to use that device at any cost. Either of the users will not be able to use the device if the process of ownership has not been carried out properly. This also takes care of the scenario when the device has been stolen or lost, avoiding the impersonation attack. The aim of this paper is to model basic process of proposed ownership authentication transfer protocol and check its safety properties by representing it using CSP and model checking approach. For model checking we have used a symbolic model checker tool called NuSMV. The safety properties of ownership transfer protocol has been modeled in terms of CTL specification and it is observed that the system satisfies all the protocol constraint and is safe to be deployed.Comment: 16 pages, 7 figures,Submitted to ADCOM 201

    Entropic Inequalities for a Class of Quantum Secret Sharing States

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    It is well-known that von Neumann entropy is nonmonotonic unlike Shannon entropy (which is monotonically nondecreasing). Consequently, it is difficult to relate the entropies of the subsystems of a given quantum state. In this paper, we show that if we consider quantum secret sharing states arising from a class of monotone span programs, then we can partially recover the monotonicity of entropy for the so-called unauthorized sets. Furthermore, we can show for these quantum states the entropy of the authorized sets is monotonically nonincreasing.Comment: LaTex, 5 page

    Laparoscopy and loop colostomy : a new approach to extra-peritoneal rectal injuries

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    Includes bibliographical references.Distal rectal washout and presacral drainage appear to have little or no influence on the morbidity and mortality in patients with low-energy trauma to the rectum. The ever-increasing popularity and obvious advantages of minimal access surgery have prompted surgeons to apply its use to a variety of surgical diseases, including trauma-related conditions. This study retrospectively reviews and examines the safety and efficacy of laparoscopy and the formation of a diverting sigmoid loop colostomy through an abdominal wall trephine, in a limited number of carefully selected patients with isolated extra-peritoneal rectal injuries. The patient is thus spared a major laparotomy wound. The value of distal rectal washout and presacral drainage in such injuries is also examined
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