26,159 research outputs found
Surface spectral function in the superconducting state of a topological insulator
We discuss the surface spectral function of superconductors realized from a
topological insulator, such as the copper-intercalated BiSe. These
functions are calculated by projecting bulk states to the surface for two
different models proposed previously for the topological insulator. Dependence
of the surface spectra on the symmetry of the bulk pairing order parameter is
discussed with particular emphasis on the odd-parity pairing. Exotic spectra
like an Andreev bound state connected to the topological surface states are
presented.Comment: 12 pages, 9 figures, 1 tabl
Broadband Tissue Mimicking Phantoms and a Patch Resonator for Evaluating Noninvasive Monitoring of Blood Glucose Levels
(c) 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.This post-acceptance version of the paper is essentially complete, but may differ from the official copy of record, which can be found at the following web location (subscription required to access full paper): http://dx.doi.org/10/1109/TAP.2014.2313139
Towards Accurate Dielectric Property Retrieval of Biological Tissues for Blood Glucose Monitoring
(c) 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted
components of this work in other works.This post-acceptance version of the paper is essentially complete, but may differ from the official copy of record, which can be found at the following web location (subscription required to access full paper): http://dx.doi.org/10/1109/TMTT.2014.2365019
Distributed Data Summarization in Well-Connected Networks
We study distributed algorithms for some fundamental problems in data summarization. Given a communication graph G of n nodes each of which may hold a value initially, we focus on computing sum_{i=1}^N g(f_i), where f_i is the number of occurrences of value i and g is some fixed function. This includes important statistics such as the number of distinct elements, frequency moments, and the empirical entropy of the data.
In the CONGEST~ model, a simple adaptation from streaming lower bounds shows that it requires Omega~(D+ n) rounds, where D is the diameter of the graph, to compute some of these statistics exactly. However, these lower bounds do not hold for graphs that are well-connected. We give an algorithm that computes sum_{i=1}^{N} g(f_i) exactly in {tau_{G}} * 2^{O(sqrt{log n})} rounds where {tau_{G}} is the mixing time of G. This also has applications in computing the top k most frequent elements.
We demonstrate that there is a high similarity between the GOSSIP~ model and the CONGEST~ model in well-connected graphs. In particular, we show that each round of the GOSSIP~ model can be simulated almost perfectly in O~({tau_{G}}) rounds of the CONGEST~ model. To this end, we develop a new algorithm for the GOSSIP~ model that 1 +/- epsilon approximates the p-th frequency moment F_p = sum_{i=1}^N f_i^p in O~(epsilon^{-2} n^{1-k/p}) roundsfor p >= 2, when the number of distinct elements F_0 is at most O(n^{1/(k-1)}). This result can be translated back to the CONGEST~ model with a factor O~({tau_{G}}) blow-up in the number of rounds
Parity restoration in the Highly Truncated Diagonalization Approach: application to the outer fission barrier of Pu
The restoration of the parity symmetry has been performed in the framework of
the Highly Truncated Diagonalization Approach suited to treat correlations in
an explicitly particle-number conserving microscopic approach. To do so we have
assumed axial symmetry and used a generalized Wick's theorem due to L\"owdin in
a projection-after-variation scheme. We have chosen the Skyrme SkM
energy-density functional for the particle-hole channel and a
density-independent delta force for the residual interaction. We have applied
this approach in the region of the outer fission barrier of the Pu
nucleus. As a result, we have shown that the fission isomeric
state is statically unstable against intrinsic-parity breaking modes, while the
projection does not affect the energy at the top of the intrinsic outer fission
barrier. Altogether, this leads to an increase of the height of the outer
fission barrier--with respect to the fission isomeric state--by about 350 keV,
affecting thus significantly the fission-decay lifetime of the considered
fission isomer
Phase structure tuned electrocaloric effect and pyroelectric energy harvesting performance of (Pb0.97La0.02)(Zr,Sn,Ti)O3 antiferroelectric thick films
In present work, (100)-oriented (Pb0.97La0.02)(Zr0.95-xSnxTi0.05)O3 antiferroelectric thick films with x=0.08, 0.20 and 0.38, were successfully fabricated. These compositions are located in orthorhombic phase region, the morphotropic phase boundary (MPB), and tetragonal phase region, respectively. The effects of their phase structure on the electrocaloric effect and the pyroelectric energy harvesting behavior were investigated. A considerable temperature reduction of ∆T=13, 33, and 27 oC, due to the ferroelectric-antiferroelectric phase transition, was obtained at 25 oC in these thick films for x=0.08, 0.20, and 0.38, respectively. Moreover, a huge harvested energy density per cycle of W= 3.6, 6.8, and 4.0 J/cm3 was also realized under the experimental condition in the thick films with x=0.08, 0.20, and 0.38, respectively. These results indicated that both the cooling performance and the pyroelectric energy harvesting in antiferroelectrics could be optimized by the proper phase structure control
Use of FBG sensors for SHM in aerospace structures
This paper details some significant findings on the use of the fiber Bragg grating (FBG) sensors for structural health monitoring (SHM) in aerospace fiber reinforced polymer (FRP)
structures. A diminutive sensor provides a capability of imbedding inside FRP structures to monitor vital locations of damage. Some practical problems associated with the implementation of FBG based SHM systems in the aerospace FRP structures such as the difficulty of embedding FBG
sensors during the manufacturing process and interrelation of distortion to FBG spectra due to internal damage, and other independent effects will be thoroughly studied. An innovative method to interpret FBG signals for identifying damage inside the structures will also be discussed
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