A CaO-Bi2O3-Al2O3-B2O3 glass system was studied as a sealant for sodium-sulfur battery. The thermal properties such as thermal expansion coefficient, glass transition, and softening temperature were determined by dilatometry and differential scanning calorimetry. Selected glasses, based on the thermal properties, were bonded with α-alumina substrate followed by aging in air at 400°C for 100 hours and in sodium vapor at 350°C for 100 hours. The interfacial compatibility and resistance to sodium vapor corrosion of the bonded and aged samples were evaluated by structural and microstructural analysis using X-ray diffractometer (XRD) and scanning electron microscope (SEM) attached with energy dispersive spectroscope (EDS). Helium leakage test was performed at room temperature to examine the sealing ability of the select glass. It is found that Bi2O3 increases the thermal expansion coefficient, decreases the glass transition and softening temperature, shows excellent interfacial compatibility and thermal cycling resistance, improves sealing ability, and degrades sodium corrosion resistance. 相似文献
Current work introduces a fast converging neural network-based approach for solution of ordinary and partial differential equations. Proposed technique eliminates the need of time-consuming optimization procedure for training of neural network. Rather, it uses the extreme learning machine algorithm for calculating the neural network parameters so as to make it satisfy the differential equation and associated boundary conditions. Various ordinary and partial differential equations are treated using this technique, and accuracy and convergence aspects of the procedure are discussed.
Multimedia Tools and Applications - Image watermarking in wavelet domain has been found useful for copyright protection and rightful ownership. Classical wavelet transforms, like discrete wavelet... 相似文献
The Internet of Things (IoT) has emerged as one of the most revolutionary technological innovations with the proliferation of applications within almost all fields of the human race. A cloud environment is the main component of IoT infrastructure to make IoT devices efficient, safe, reliable, usable, and autonomous. Reduction in infrastructure cost and demand accessibility of shared resources are essential parts of cloud-based IoT (CIoT) infrastructure. Information leakage in cloud-assisted IoT devices may invite dangerous activities and phenomena. Various cloud-based systems store IoT sensor data and later on access it accordingly. Some of them are public, and some of them are private. Private cloud services must be secured from external as well as internal adversaries. Hence, there must be a robust mechanism to prevent unauthorized access to devices. This paper proposes a novel and efficient protocol based on the Elliptic Curve property known as Elliptic Curve Discrete Logarithm Problem (ECDLP) with hash and XOR functions for the authentication in cloud-based IoT devices. In comparison to the existing protocols, the proposed protocol is resistant to attacks and other security vulnerabilities. The one-way hash function and XOR function effectively ensure a reduction in computation cost. AVISPA and BAN logic have been used for formal analysis of the proposed protocol. As per the performance analysis results, it is clear that the proposed protocol is efficiently suitable for cloud-assisted IoT devices.
In the paper by S. Chen et al. (see ibid., vol.2, no.3, p.311-19, 1990), the authors proposed an algorithm which determines whether there exists an antecedent-consequence relationship from a fuzzy proposition d s to proposition dj and if the degree of truth of proposition ds is given, then the degree of truth of proposition dj can be evaluated. The fuzzy reasoning algorithm proposed by S. Chen et al. (1990) was found not to be working with all types of data. We propose: (1) a modified form of the algorithm, and (2) a concept of hierarchical fuzzy Petri nets for data abstraction 相似文献
In this work, a composite numerical scheme based on finite difference and Haar wavelets is proposed to solve time dependent coupled Burgers’ equation with appropriate initial and boundary conditions. Time derivative is discretized by forward difference and then quasilinearization technique is used to linearize the coupled Burgers’ equation. Space derivatives discretization with Haar wavelets leads to a system of linear equations and is solved using Matlab7.0. Convergence analysis of proposed scheme exhibits that the error bound is inversely proportional to the resolution level of the Haar wavelet. Finally, the adaptability of proposed scheme is demonstrated by numerical experiments and shows that the present composite scheme offers better accuracy in comparison with other existing numerical methods. 相似文献
We analyse the performance and dependability of protocols which implement ‘sequence consistency’ in distributed replicated systems. Sites send messages to each other from time to time, passing information about the update requests that have been received. The recipient of a message is chosen according to some probability distribution which may depend on the sender. The random variables of main interest are (a) the interval between receiving an update request and being able to execute it on the original site, subject to the consistency requirement, and (b) the time it takes to bring all sites to a consistent state after the arrival of an update. 相似文献
We propose an optical scheme for quantum key distribution in which bits are encoded in relative phases of four bipartite weak coherent states${|\alpha, \alpha\rangle, |-\alpha, -\alpha\rangle, |-\alpha, \alpha\rangle}$ and ${|\alpha, -\alpha \rangle}$, with respect to a strong reference pulse. We discuss security of the scheme against eavesdropping strategies like, photon number splitting, photon beam splitting and intercept-resend attacks. It is found that present scheme is more sensitive against these eavesdropping strategies than the two-dimensional non-orthogonal state based protocol and BB84 protocol. Our scheme is very simple, requires only passive optical elements like beam splitters, phase shifters and photon detectors, hence is at the reach of presently available technology. 相似文献
The median (antimedian) set of a profile π=(u1,…,uk) of vertices of a graph G is the set of vertices x that minimize (maximize) the remoteness ∑id(x,ui). Two algorithms for median graphs G of complexity O(n idim(G)) are designed, where n is the order and idim(G) the isometric dimension of G. The first algorithm computes median sets of profiles and will be in practice often faster than the other algorithm which
in addition computes antimedian sets and remoteness functions and works in all partial cubes. 相似文献