Generation of cluster states

We propose two schemes for the generation of the cluster states. One is based on cavity quantum electrodynamics (QED) techniques. The scheme only requires resonant interactions between two atoms and a single-mode cavity. The interaction time is very short, which is important in view of decoherence. Furthermore, we also discuss the cavity decay and atomic spontaneous emission case. The other is based on atomic ensembles. The scheme has inherent fault tolerance function and is robust to realistic noise and imperfections. All the facilities used in our schemes are well within the current technology.Comment: Complete rewite version, adding the main results of quant-ph/0511045. 7 pages and 3 figure

Two-stream convolutional neural network for non-destructive subsurface defect detection via similarity comparison of lock-in thermography signals

Active infrared thermography is a safe, fast, and low-cost solution for subsurface defects inspection, providing quality control in many industrial production tasks. In this paper, we explore deep learning-based approaches to analyze lock-in thermography image sequences for non-destructive testing and evaluation (NDT&amp;E) of subsurface defects. Different from most existing Convolutional Neural Network (CNN) models that directly classify individual regions/pixels as defective and non-defective ones, we present a novel two-stream CNN architecture to extract/compare features in a pair of 1D thermal signal sequences for accurate classification/differentiation of defective and non-defective regions. In this manner, we can significantly increase the size of the training data by pairing two individually captured 1D thermal signals, thereby greatly easing the requirement for collecting a large number of thermal sequences of specimens with defects to train deep CNN models. Moreover, we experimentally investigate a number of network alternatives, identifying the optimal fusion scheme/stage for differentiating the thermal behaviors of defective and non-defective regions. Experimental results demonstrate that our proposed method, directly learning how to construct feature representations from a large number of real-captured thermal signal pairs, outperforms the well-established lock-in thermography data processing techniques on specimens made of different materials and at various excitation frequencies.</p

Fast Blind Audio Copy-Move Detection and Localization Using Local Feature Tensors in Noise

The increasing availability of audio editing software altering digital audios and their ease of use allows create forgeries at low cost. A copy-move forgery (CMF) is one of easiest and popular audio forgeries, which created by copying and pasting audio segments within the same audio, and potentially post-processing it. Three main approaches to audio copy-move detection exist nowadays: samples/frames comparison, acoustic features coherence searching and dynamic time warping. But these approaches will suffer from computational complexity and/or sensitive to noise and post-processing. In this paper, we propose a new local feature tensors-based copy-move detection algorithm that can be applied to transformed duplicates detection and localization problem to a special locality sensitive hash like procedure. The experimental results with massive online real-time audios datasets reveal that the proposed technique effectively determines and locating copy-move forgeries even on a forged speech segment are as short as fractional second. This method is also computational efficient and robust against the audios processed with severe nonlinear transformation, such as resampling, filtering, jsittering, compression and cropping, even contaminated with background noise and music. Hence, the proposed technique provides an efficient and reliable way of copy-move forgery detection that increases the credibility of audio in practical forensics application

Spectroscopy and Formation of Lanthanum-Hydrocarbon Radicals Formed by Association and Carbon-Carbon Bond Cleavage of Isoprene

La atom reaction with isoprene is carried out in a laser-vaporization molecular beam source. The reaction yields an adduct as the major product and C—C cleaved and dehydrogenated species as the minor ones. La(C5H8), La(C2H2), and La(C3H4) are characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of all three species exhibit a strong origin band and several weak vibronic bands corresponding to La-ligand stretch and ligand-based bend excitations. La(C5H8) is a five-membered metallacycle, whereas La(C2H2) and La(C3H4) are three-membered rings. All three metallacycles prefer a doublet ground state with a La 6s1-based valence electron configuration and a singlet ion. The five-membered metallacycle is formed through La addition and isoprene isomerization, whereas the two three-membered rings are produced by La addition and insertion, hydrogen migration, and carbon-carbon bond cleavage

Lanthanum-Mediated Dehydrogenation of Butenes: Spectroscopy and Formation of La(C\u3csub\u3e4\u3c/sub\u3eH\u3csub\u3e6\u3c/sub\u3e) Isomers

La atom reactions with 1-butene, 2-butene, and isobutene are carried out in a laser-vaporization molecular beam source. The three reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butenes. The dehydrogenated species La(C4H6) is the major product, which is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectrum of La(C4H6) produced from the La+1-butene reaction exhibits two band systems, whereas the MATI spectra produced from the La+2-butene and isobutene reactions display only a single band system. Each of these spectra shows a strong origin band and several vibrational progressions. The two band systems from the spectrum of the 1-butene reaction are assigned to the ionization of two isomers: La[C(CH2)3] (Iso A) and La(CH2CHCHCH2) (Iso B), and the single band system from the spectra of the 2-butene and isobutene reactions is attributed to Iso B and Iso A, respectively. The ground electronic states are 2A1 (C3v) for Iso A and 2A′ (Cs) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and leads to the 1A1 ion of Iso A and the 1A′ ion of Iso B. The formation of both isomers consists of La addition to the C=C double bond, La insertion into two C(sp3)—H bonds, and H2 elimination. In addition to these steps, the formation of Iso A from the La+1-butene reaction may involve the isomerization of 1-butene to isobutene prior to the C—H bond activation, whereas the formation of Iso B from the La+trans-2-butene reaction may include the trans- to cis-butene isomerization after the C—H bond activation

Lanthanum-Mediated Dehydrogenation of 1- and 2-Butynes: Spectroscopy and Formation of La(C\u3csub\u3e4\u3c/sub\u3eH\u3csub\u3e4\u3c/sub\u3e) Isomers

La atom reactions with 1-butyne and 2-butyne are carried out in a laser-vaporization molecular beam source. Both reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butynes. The dehydrogenated species La(C4H4) is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of La(C4H4) produced from the two reactions exhibit two identical transitions, each consisting of a strong origin band and several vibrational intervals. The two transitions are assigned to the ionization of two isomers: La(η4–CH2CCCH2) (Iso A) and La(η4–CH2CHCCH) (Iso B). The ground electronic states are 2A1 (C2v) for Iso A and 2A (C1) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and results in a 1A1 ion of Iso A and a 1A ion of Iso B. The formation of Iso A from 2-butyne and Iso B from 1-butyne involves the addition of La to the C≡C triple bond, the activation of two C(sp3)–H bonds, and concerted elimination of a H2 molecule. The formation of Iso A from 1-butyne and Iso B from 2-butyne involves the isomerization of the two butynes to 1,2-butadiene in addition to the concerted H2 elimination