3,504 research outputs found

    Deterministic versus probabilistic quantum information masking

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    We investigate quantum information masking for arbitrary dimensional quantum states. We show that mutually orthogonal quantum states can always be served for deterministic masking of quantum information. We further construct a probabilistic masking machine for linearly independent states. It is shown that a set of d dimensional states, {a1A,ta2A,,anA}\{ |a_1 \rangle_A, |t a_2 \rangle_A, \dots, |a_n \rangle_A \}, ndn \leq d, can be probabilistically masked by a general unitary-reduction operation if they are linearly independent. The maximal successful probability of probabilistic masking is analyzed and derived for the case of two initial states.Comment: 5 pages, 1 figure

    N-Cyclo­hexyl-3-(4-hydr­oxy-6-oxo-1,6-dihydro­pyrimidin-5-yl)-3-p-tolyl­propanamide

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    In the mol­ecule of the title compound, C20H25N3O3, the aromatic rings are oriented at a dihedral angle of 88.36 (3)°. The cyclo­hexane ring adopts a chair conformation. In the crystal structure, inter­molecular N—H⋯O and O—H⋯N hydrogen bonds link the mol­ecules. C—H⋯π inter­actions are also present

    Experimental study on the validity of flow region division

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    Einstein first proposed that a river flow can be divided into three parts, corresponding to the banks and its bed, respectively, but he did not explain why the flow is dividable and how to divide the flow, in other words the flow division is only a mathematical treatment to simplify his analysis. Since Einstein\u27s proposition there have been many researches and debates on this topic, many division lines have been proposed, but there is no specially designed experimental research to verify the physical existence of division lines, and these division lines have not been tested against the experimental data. For this purpose, an experiment in a rectangular open channel was conducted to measure whether zero-shear stress exists in an open channel except its existence on the free surface. The measured results reveal that zero-shear stress indeed exists below the free surface, and some proposed equations of division line agree well with the profile of the measured zero-shear line, thus it is clarified that Einstein\u27s hypothesis is not only useful to simplify the mathematical treatment, but also it has the physical basis, i.e., zero-shear division line. As far as the authors know, in the literature, this is the first experimental proof that the division lines indeed exist in channel flows

    Biomechanics Characteristics of New Type Artificial Hip Joint

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    The structure, geometrical shape and material are the three main parts of the prostheses. This research focuses on the geometrical shape analysis. The geometrical shape of human natural femoral head is similar to the ellipse, but, the artificial femoral head is rotundity shape. There is difference between ellipse and rotundity femoral head. Two models are developed and analyzed in this paper under same conditions used Finite element analysis method. Based on the calculation results, it is shown that the ellipse shape femoral head have the similar characteristics to the natural joint than rotundity model. The ellipse has the more lowness stress distribution area and more small distortion magnitude than rotundity shape artificial femoral head. It should have the more kind effect replace rotundity femoral head with ellipse shape artificial formal head. Keywords: hip joint; prosthesis design; finite element analysis; biomechanic

    An efficient approach of secure group association management in densely deployed heterogeneous distributed sensor network

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    A heterogeneous distributed sensor network (HDSN) is a type of distributed sensor network where sensors with different deployment groups and different functional types participate at the same time. In other words, the sensors are divided into different deployment groups according to different types of data transmissions, but they cooperate with each other within and out of their respective groups. However, in traditional heterogeneous sensor networks, the classification is based on transmission range, energy level, computation ability, and sensing range. Taking this model into account, we propose a secure group association authentication mechanism using one-way accumulator which ensures that: before collaborating for a particular task, any pair of nodes in the same deployment group can verify the legitimacy of group association of each other. Secure addition and deletion of sensors are also supported in this approach. In addition, a policy-based sensor addition procedure is also suggested. For secure handling of disconnected nodes of a group, we use an efficient pairwise key derivation scheme to resist any adversary’s attempt. Along with proposing our mechanism, we also discuss the characteristics of HDSN, its scopes, applicability, future, and challenges. The efficiency of our security management approach is also demonstrated with performance evaluation and analysis
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