9,307 research outputs found

    Anatomical Changes in the Skin of Rattus Norvegicus After Artificial UV Exposure

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    Acute and subacute artificial UV exposure to albino rats exhibit morphological and histo-anatomical changes in the skin of albino rat. The anatomical changes include hyperplasia, hyperkeratosis, hypergranulosis and acanthosis beside numerical changes in keratinocytes, Langerhans, melanocytes and fibroblast seen after acute and subacute artificial UVB exposure

    Dynamic Secrets and Secret Keys Based Scheme for Securing Last Mile Smart Grid Wireless Communication

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    An integrated and optimized smart grid cannot be achieved without a secure communication network. Due to the large-scale nature of the power system, the variety of technologies used, and limitations of communication bandwidth, supervisory applications for smart grid still use weak security in many deployments. Adversaries can potentially modify measurement values or inject bad commands over the network. In this paper, we propose a novel scheme based on dynamic secrets and encryption with secret keys. The scheme generates a series of dynamic secrets over the communication network, which are used to generate secret keys for data encryption. The generation of dynamic secret is frequent and no adversary can compromise the network for a longer period, even if he/she knows a secret key. The scheme is secure against eavesdropping, malicious communication injection, man-in-the-middle attack, replay attack, impersonation attack, and chosen-plaintext attack. The security analysis and performance evaluation show that our scheme is feasible to be used in the communication between supervisory and control nodes of various smart grid applications

    Authentication protocol for an IoT-enabled LTE networks

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    The Evolved Packet System-based Authentication and Key Agreement (EPS-AKA) protocol of the long-term evolution (LTE) network does not support Internet of Things (IoT) objects and has several security limitations, including transmission of the object’s (user/device) identity and key set identifier in plaintext over the network, synchronization, large overhead, limited identity privacy, and security attack vulnerabilities. In this article, we propose a new secure and efficient AKA protocol for the LTE network that supports secure and efficient communications among various IoT devices as well as among the users. Analysis shows that our protocol is secure, efficient, and privacy preserved, and reduces bandwidth consumption during authentication

    Error latency estimation using functional fault modeling

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    A complete modeling of faults at gate level for a fault tolerant computer is both infeasible and uneconomical. Functional fault modeling is an approach where units are characterized at an intermediate level and then combined to determine fault behavior. The applicability of functional fault modeling to the FTMP is studied. Using this model a forecast of error latency is made for some functional blocks. This approach is useful in representing larger sections of the hardware and aids in uncovering system level deficiencies

    Securing Restricted Publisher-Subscriber Communications in Smart Grid Substations

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    Smart Grid applications require accurate and correct data transmission from publisher to subscribers with critical communication latency requirements. Since the smart grid is being supported by distributed communication networks, deployed using various wired and wireless technologies, including IP-based networks, securing the communication infrastructure is both critically important and challenging. In this paper, we propose a secure and efficient data delivery scheme, based on a restricted yet dynamic publisher-subscriber architecture, for the published messages from a publisher to the subscribers distributed in the smart grid network. The scheme ensures that the published message is delivered from an authentic publisher to only those authorized subscribers by verifying publisher's signature and access structure of all subscribers. Operation overheads are reduced by performing only one encryption and decryption or hashing per subscriber location using a proxy node as a remote terminal unit. Our analysis shows that the scheme is resistant against replay, man-in-the-middle, and impersonation attacks. Performance evaluation shows that the scheme can support 600 subscribers given the communication latency requirement of 3 ms. We provide the performance of the scheme under different scenarios, and observe that the efficiency of our scheme increases as the ratio of the geographical locations within a substation to the number of subscribers increases

    Domain Wall and Periodic Solutions of Coupled phi4 Models in an External Field

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    Coupled double well (phi4) one-dimensional potentials abound in both condensed matter physics and field theory. Here we provide an exhaustive set of exact periodic solutions of a coupled ϕ4\phi^4 model in an external field in terms of elliptic functions (domain wall arrays) and obtain single domain wall solutions in specific limits. We also calculate the energy and interaction between solitons for various solutions. Both topological and nontopological (e.g. some pulse-like solutions in the presence of a conjugate field) domain walls are obtained. We relate some of these solutions to the recently observed magnetic domain walls in certain multiferroic materials and also in the field theory context wherever possible. Discrete analogs of these coupled models, relevant for structural transitions on a lattice, are also considered.Comment: 35 pages, no figures (J. Math. Phys. 2006

    Evaluation of CNN-based Single-Image Depth Estimation Methods

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    While an increasing interest in deep models for single-image depth estimation methods can be observed, established schemes for their evaluation are still limited. We propose a set of novel quality criteria, allowing for a more detailed analysis by focusing on specific characteristics of depth maps. In particular, we address the preservation of edges and planar regions, depth consistency, and absolute distance accuracy. In order to employ these metrics to evaluate and compare state-of-the-art single-image depth estimation approaches, we provide a new high-quality RGB-D dataset. We used a DSLR camera together with a laser scanner to acquire high-resolution images and highly accurate depth maps. Experimental results show the validity of our proposed evaluation protocol

    Soliton Lattice and Single Soliton Solutions of the Associated Lam\'e and Lam\'e Potentials

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    We obtain the exact nontopological soliton lattice solutions of the Associated Lam\'e equation in different parameter regimes and compute the corresponding energy for each of these solutions. We show that in specific limits these solutions give rise to nontopological (pulse-like) single solitons, as well as to different types of topological (kink-like) single soliton solutions of the Associated Lam\'e equation. Following Manton, we also compute, as an illustration, the asymptotic interaction energy between these soliton solutions in one particular case. Finally, in specific limits, we deduce the soliton lattices, as well as the topological single soliton solutions of the Lam\'e equation, and also the sine-Gordon soliton solution.Comment: 23 pages, 5 figures. Submitted to J. Math. Phy

    On the Limits of Depth Reduction at Depth 3 Over Small Finite Fields

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    Recently, Gupta et.al. [GKKS2013] proved that over Q any nO(1)n^{O(1)}-variate and nn-degree polynomial in VP can also be computed by a depth three ΣΠΣ\Sigma\Pi\Sigma circuit of size 2O(nlog3/2n)2^{O(\sqrt{n}\log^{3/2}n)}. Over fixed-size finite fields, Grigoriev and Karpinski proved that any ΣΠΣ\Sigma\Pi\Sigma circuit that computes DetnDet_n (or PermnPerm_n) must be of size 2Ω(n)2^{\Omega(n)} [GK1998]. In this paper, we prove that over fixed-size finite fields, any ΣΠΣ\Sigma\Pi\Sigma circuit for computing the iterated matrix multiplication polynomial of nn generic matrices of size n×nn\times n, must be of size 2Ω(nlogn)2^{\Omega(n\log n)}. The importance of this result is that over fixed-size fields there is no depth reduction technique that can be used to compute all the nO(1)n^{O(1)}-variate and nn-degree polynomials in VP by depth 3 circuits of size 2o(nlogn)2^{o(n\log n)}. The result [GK1998] can only rule out such a possibility for depth 3 circuits of size 2o(n)2^{o(n)}. We also give an example of an explicit polynomial (NWn,ϵ(X)NW_{n,\epsilon}(X)) in VNP (not known to be in VP), for which any ΣΠΣ\Sigma\Pi\Sigma circuit computing it (over fixed-size fields) must be of size 2Ω(nlogn)2^{\Omega(n\log n)}. The polynomial we consider is constructed from the combinatorial design. An interesting feature of this result is that we get the first examples of two polynomials (one in VP and one in VNP) such that they have provably stronger circuit size lower bounds than Permanent in a reasonably strong model of computation. Next, we prove that any depth 4 ΣΠ[O(n)]ΣΠ[n]\Sigma\Pi^{[O(\sqrt{n})]}\Sigma\Pi^{[\sqrt{n}]} circuit computing NWn,ϵ(X)NW_{n,\epsilon}(X) (over any field) must be of size 2Ω(nlogn)2^{\Omega(\sqrt{n}\log n)}. To the best of our knowledge, the polynomial NWn,ϵ(X)NW_{n,\epsilon}(X) is the first example of an explicit polynomial in VNP such that it requires 2Ω(nlogn)2^{\Omega(\sqrt{n}\log n)} size depth four circuits, but no known matching upper bound
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