11,132 research outputs found

    Single machine slack due-window assignment and scheduling of linear time-dependent deteriorating jobs and a deteriorating maintenance activity

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    In this paper, we consider the slack due-window assignment model and study a single machine scheduling problem of linear time-dependent deteriorating jobs and a deteriorating maintenance activity. The cost for each job consists of four components: earliness, tardiness, window location and window size. The objective is to schedule the jobs and to assign the maintenance activity and due-windows such that the total cost among all the jobs is minimized. A polynomial-time algorithm with the running time not exceeding O(n2logn)O(n^2logn) to give a solution to this problem is introduced, where nn is the number of jobs.Comment: Submitted - Under Revie

    Long-wavelength fluctuations and static correlations in quasi-2D colloidal suspensions

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    Dimensionality strongly affects thermal fluctuations and critical dynamics of equilibrium systems. These influences persist in amorphous systems going through the nonequilibrium glass transition. Here, we experimentally study the glass transition of quasi-2D suspensions of spherical and ellipsoidal particles under different degrees of circular confinement. We show that the strength of the long-wavelength fluctuations increases logarithmically with system sizes and displays the signature of the Mermin-Wagner fluctuations. Moreover, using confinement as a tool, we also measure static structural correlations and extract a growing static correlation length in 2D supercooled liquids. Finally, we explore the influence of the Mermin-Wagner fluctuations on the translational and orientational relaxations of 2D ellipsoidal suspensions, which leads to a new interpretation of the two-step glass transition and the orientational glass phase of anisotropic particles. Our study reveals the importance of long-wavelength fluctuations in 2D supercooled liquids and provides new insights into the role of dimensionality in the glass transition.Comment: 11 pages, 12 figures, Soft Matter (accepted

    Composite Behavioral Modeling for Identity Theft Detection in Online Social Networks

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    In this work, we aim at building a bridge from poor behavioral data to an effective, quick-response, and robust behavior model for online identity theft detection. We concentrate on this issue in online social networks (OSNs) where users usually have composite behavioral records, consisting of multi-dimensional low-quality data, e.g., offline check-ins and online user generated content (UGC). As an insightful result, we find that there is a complementary effect among different dimensions of records for modeling users' behavioral patterns. To deeply exploit such a complementary effect, we propose a joint model to capture both online and offline features of a user's composite behavior. We evaluate the proposed joint model by comparing with some typical models on two real-world datasets: Foursquare and Yelp. In the widely-used setting of theft simulation (simulating thefts via behavioral replacement), the experimental results show that our model outperforms the existing ones, with the AUC values 0.9560.956 in Foursquare and 0.9470.947 in Yelp, respectively. Particularly, the recall (True Positive Rate) can reach up to 65.3%65.3\% in Foursquare and 72.2%72.2\% in Yelp with the corresponding disturbance rate (False Positive Rate) below 1%1\%. It is worth mentioning that these performances can be achieved by examining only one composite behavior (visiting a place and posting a tip online simultaneously) per authentication, which guarantees the low response latency of our method. This study would give the cybersecurity community new insights into whether and how a real-time online identity authentication can be improved via modeling users' composite behavioral patterns

    Maximally symmetric subspace decomposition of the Schwarzschild black hole

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    The well-known Schwarzschild black hole was first obtained as a stationary, spherically symmetric solution of the Einstein's vacuum field equations. But until thirty years later, efforts were made for the analytic extension from the exterior area (r>2GM)(r>2GM) to the interior one (r<2GM)(r<2GM). As a contrast to its maximally extension in the Kruskal coordinates, we provide a comoving coordinate system from the view of the observers freely falling into the black hole in the radial direction. We find an interesting fact that the spatial part in this coordinate system is maximally symmetric (E3)(E_3), i.e., along the world lines of these observers, the Schwarzschild black hole can be decomposed into a family of maximally symmetric subspaces.Comment: Plain LaTex2e File, 8 pages, 1 eps figur

    Statistical properties of radiation fields in a compact space

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    We discuss radiation fields in a compact space of finite size instead of that in a cavity for investigating the coupled atom-radiation field system. Representations of T(1)×SO(4)T(1)\times SO(4) group are used to give a formulation for kinematics of the radiation fields. The explicit geometrical parameter dependence of statistical properties of radiation fields is obtained. Results show remarkable differences from that of the black-body radiation system in free space.Comment: LaTeX2e plain file of 10 pages, 1 eps figur

    Pc(4457)+P_c(4457)^+, Pc(4440)+P_c(4440)^+, and Pc(4312)+P_c(4312)^+: molecules or compact pentaquarks?

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    In a chromomagnetic model, we analyse the properties of the newly observed Pc(4457)+P_c(4457)^+, Pc(4440)+P_c(4440)^+, and Pc(4312)+P_c(4312)^+ states. We estimate the masses of the (uud)8c(ccˉ)8c(uud)_{8_c}(c\bar{c})_{8_c} and (uds)8c(ccˉ)8c(uds)_{8_c}(c\bar{c})_{8_c} pentaquark states by considering the isospin breaking effects. Their values are determined by calculating mass distances from the Σc++D\Sigma_c^{++}D^- and Ξc+D\Xi_c^{\prime+}D^- thresholds, respectively. It is found that the isospin breaking effects on the spectrum are small. From the uncertainty consideration and the rearrangement decay properties in a simple model, we find that it is possible to assign the Pc(4457)+P_c(4457)^+, Pc(4440)+P_c(4440)^+, and Pc(4312)+P_c(4312)^+ as JP=3/2J^P=3/2^-, 1/21/2^-, and 3/23/2^- pentaquark states, respectively. The assignment in the molecule picture can be different, in particular for the Pc(4312)+P_c(4312)^+. The information from open-charm channels, e.g. B[PcΣc++D]/B[PcJ/ψp]{\cal B}[P_c\to\Sigma_c^{++}D^-]/{\cal B}[P_c\to J/\psi p], will play an important role in distinguishing the inner structures of the PcP_c states. Discussions and predictions based on the calculations are also given.Comment: 15 pages, 2 figures, 8 tables. Version accepted by PR

    Well-Supported versus Approximate Nash Equilibria: Query Complexity of Large Games

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    We study the randomized query complexity of approximate Nash equilibria (ANE) in large games. We prove that, for some constant ϵ>0\epsilon>0, any randomized oracle algorithm that computes an ϵ\epsilon-ANE in a binary-action, nn-player game must make 2Ω(n/logn)2^{\Omega(n/\log n)} payoff queries. For the stronger solution concept of well-supported Nash equilibria (WSNE), Babichenko previously gave an exponential 2Ω(n)2^{\Omega(n)} lower bound for the randomized query complexity of ϵ\epsilon-WSNE, for some constant ϵ>0\epsilon>0; the same lower bound was shown to hold for ϵ\epsilon-ANE, but only when ϵ=O(1/n)\epsilon=O(1/n). Our result answers an open problem posed by Hart and Nisan and Babichenko and is very close to the trivial upper bound of 2n2^n. Our proof relies on a generic reduction from the problem of finding an ϵ\epsilon-WSNE to the problem of finding an ϵ/(4α)\epsilon/(4\alpha)-ANE, in large games with α\alpha actions, which might be of independent interest.Comment: 10 page

    Multipartite entanglement, quantum coherence, and quantum criticality in triangular and Sierpi\'nski fractal lattices

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    We investigate the quantum phase transitions of the transverse-field quantum Ising model on the triangular lattice and Sierpi\'nski fractal lattices by employing multipartite entanglement and quantum coherence along with the quantum renormalization group method. It is shown that the quantum criticalities of these high-dimensional models closely relate to the behaviors of the multipartite entanglement and quantum coherence. As the thermodynamic limit is approached, the first derivatives of multipartite entanglement and quantum coherence exhibit singular behaviors and the consistent finite-size scaling behaviors for each lattice are also obtained from the first derivatives. The multipartite entanglement and quantum coherence are demonstrated to be good indicators for detecting the quantum phase transitions in the triangular lattice and Sierpi\'nski fractal lattices. Furthermore, the factors that determine the relations between the critical exponents and the correlation length exponents for these models are diverse. For the triangular lattice, the decisive factor is the spatial dimension, while for the Sierpi\'nski fractal lattices, it is the Hausdorff dimension.Comment: 12 pages; 12 figure

    SilentSense: Silent User Identification via Dynamics of Touch and Movement Behavioral Biometrics

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    With the increased popularity of smartphones, various security threats and privacy leakages targeting them are discovered and investigated. In this work, we present \ourprotocoltight, a framework to authenticate users silently and transparently by exploiting dynamics mined from the user touch behavior biometrics and the micro-movement of the device caused by user's screen-touch actions. We build a "touch-based biometrics" model of the owner by extracting some principle features, and then verify whether the current user is the owner or guest/attacker. When using the smartphone, the unique operating dynamics of the user is detected and learnt by collecting the sensor data and touch events silently. When users are mobile, the micro-movement of mobile devices caused by touch is suppressed by that due to the large scale user-movement which will render the touch-based biometrics ineffective. To address this, we integrate a movement-based biometrics for each user with previous touch-based biometrics. We conduct extensive evaluations of our approaches on the Android smartphone, we show that the user identification accuracy is over 99%

    Entanglement concentration for concatenated Greenberger-Horne-Zeiglinger state with feasible linear optics

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    The concatenated Greenberger-Horne-Zeiglinger (C-GHZ) state which is a new type of logic-qubit entanglement has attracted a lot of attentions recently. We present a feasible entanglement concentration protocol (ECP) for logic-qubit entanglement. This ECP is based on the linear optics, and it does not know the initial coefficients of the less-entangled C-GHZ state. This protocol can be extended to arbitrary C-GHZ state. This protocol may be useful in future quantum information processing tasks.Comment: 18 pages, 4 figure
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