10,590 research outputs found
Interference detection and correction applied to incoherent-scatter radar power spectrum measurement
A median filter based interference detection and correction technique is evaluated and the method applied to the Arecibo incoherent scatter radar D-region ionospheric power spectrum is discussed. The method can be extended to other kinds of data when the statistics involved in the process are still valid
Multipartite unlockable bound entanglement in the stabilizer formalism
We find an interesting relationship between multipartite bound entangled
states and the stabilizer formalism. We prove that if a set of commuting
operators from the generalized Pauli group on qudits satisfy certain
constraints, then the maximally mixed state over the subspace stabilized by
them is an unlockable bound entangled state. Moreover, the properties of this
state, such as symmetry under permutations of parties, undistillability and
unlockability, can be easily explained from the stabilizer formalism without
tedious calculation. In particular, the four-qubit Smolin state and its recent
generalization to even number of qubits can be viewed as special examples of
our results. Finally, we extend our results to arbitrary multipartite systems
in which the dimensions of all parties may be different.Comment: 7 pages, no figur
Noise bridges dynamical correlation and topology in coupled oscillator networks
We study the relationship between dynamical properties and interaction
patterns in complex oscillator networks in the presence of noise. A striking
finding is that noise leads to a general, one-to-one correspondence between the
dynamical correlation and the connections among oscillators for a variety of
node dynamics and network structures. The universal finding enables an accurate
prediction of the full network topology based solely on measuring the dynamical
correlation. The power of the method for network inference is demonstrated by
the high success rate in identifying links for distinct dynamics on both model
and real-life networks. The method can have potential applications in various
fields due to its generality, high accuracy and efficiency.Comment: 2 figures, 2 tables. Accepted by Physical Review Letter
Depth resolution of Piezoresponse force microscopy
Given that a ferroelectric domain is generally a three dimensional entity, the determination of its area as well as its depth is mandatory for full characterization. Piezoresponse force microscopy (PFM) is known for its ability to map the lateral dimensions of ferroelectric domains with high accuracy. However, no depth profile information has been readily available so far. Here, we have used ferroelectric domains of known depth profile to determine the dependence of the PFM response on the depth of the domain, and thus effectively the depth resolution of PFM detection
Nation branding: what is being branded?
Nation branding and nation brand are two different concepts. A nation has a brand image with or without nation branding. This paper examines the concept of nation branding, focusing on the central question of what is being branded. It differentiates nation branding from product branding, and draws comparisons between nation branding and product-country image. Paradoxical issues around the concept and the wider context in which nation branding can be applied are also discussed. More research is needed to find out if and how nation branding could help the economic development in a country. As many other non-marketing factors also affect a nation’s image the role played by nation branding may turn out to be only a modest one
Trade-off between multiple-copy transformation and entanglement catalysis
We demonstrate that multiple copies of a bipartite entangled pure state may
serve as a catalyst for certain entanglement transformations while a single
copy cannot. Such a state is termed a "multiple-copy catalyst" for the
transformations. A trade-off between the number of copies of source state and
that of the catalyst is also observed. These results can be generalized to
probabilistic entanglement transformations directly.Comment: Essentially the journal version. 7 pages, no figures. Minor
correction
Multiple-copy entanglement transformation and entanglement catalysis
We prove that any multiple-copy entanglement transformation [S.
Bandyopadhyay, V. Roychowdhury, and U. Sen, Phys. Rev. A \textbf{65}, 052315
(2002)] can be implemented by a suitable entanglement-assisted local
transformation [D. Jonathan and M. B. Plenio, Phys. Rev. Lett. \textbf{83},
3566 (1999)]. Furthermore, we show that the combination of multiple-copy
entanglement transformation and the entanglement-assisted one is still
equivalent to the pure entanglement-assisted one. The mathematical structure of
multiple-copy entanglement transformations then is carefully investigated. Many
interesting properties of multiple-copy entanglement transformations are
presented, which exactly coincide with those satisfied by the
entanglement-assisted ones. Most interestingly, we show that an arbitrarily
large number of copies of state should be considered in multiple-copy
entanglement transformations.Comment: 11 pages, RevTex 4. Main results unchanged. Journal versio
Towards A Holographic Model of D-Wave Superconductors
The holographic model for S-wave high T_c superconductors developed by
Hartnoll, Herzog and Horowitz is generalized to describe D-wave
superconductors. The 3+1 dimensional gravitational theory consists a symmetric,
traceless second-rank tensor field and a U(1) gauge field in the background of
the AdS black hole. Below T_c the tensor field which carries the U(1) charge
undergoes the Higgs mechanism and breaks the U(1) symmetry of the boundary
theory spontaneously. The phase transition characterized by the D-wave
condensate is second order with the mean field critical exponent beta = 1/2. As
expected, the AC conductivity is isotropic below T_c and the system becomes
superconducting in the DC limit but has no hard gap.Comment: 14 pages, 2 figures, Some typos corrected, Matched with the published
versio
Support for graphicacy: a review of textbooks available to accounting students
This Teaching Note reports on the support available in textbooks for graphicacy that will help students understand the complexities of graphical displays. Graphical displays play a significant role in financial reporting, and studies have found evidence of measurement distortion and selection bias. To understand the complexities of graphical displays, students need a sound understanding of graphicacy and support from the textbooks available to them to develop that understanding. The Teaching Note reports on a survey that examined the textbooks available to students attending two Scottish universities. The support of critical graphicacy skills was examined in conjunction with textbook characteristics. The survey, which was not restricted to textbooks designated as required reading, examined the textbooks for content on data measurement and graphical displays. The findings highlight a lack of support for graphicacy in the textbooks selected. The study concludes that accounting educators need to scrutinize more closely the selection of textbooks and calls for more extensive research into textbooks as a pedagogic tool
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