817 research outputs found
Monitoring currents in cold-atom circuits
Complex circuits of cold atoms can be exploited to devise new protocols for
the diagnostics of cold-atoms systems. Specifically, we study the quench
dynamics of a condensate confined in a ring-shaped potential coupled with a
rectilinear guide of finite size. We find that the dynamics of the atoms inside
the guide is distinctive of the states with different winding numbers in the
ring condensate. We also observe that the depletion of the density, localized
around the tunneling region of the ring condensate, can decay in a pair of
excitations experiencing a Sagnac effect. In our approach, the current states
of the condensate in the ring can be read out by inspection of the rectilinear
guide only, leaving the ring condensate minimally affected by the measurement.
We believe that our results set the basis for definition of new quantum
rotation sensors. At the same time, our scheme can be employed to explore
fundamental questions involving dynamics of bosonic condensates.Comment: Figures are enlarged. Section IV is added. Journal reference adde
Bistable behavior of a two-mode Bose-Einstein condensate in an optical cavity
We consider a two-component Bose-Einstein condensate in a one-dimensional
optical cavity. Specifically, the condensate atoms are taken to be in two
degenerate modes due to their internal hyperfine spin degrees of freedom and
they are coupled to the cavity field and an external transverse laser field in
a Raman scheme. A parallel laser is also exciting the cavity mode. When the
pump laser is far detuned from its resonance atomic transition frequency, an
effective nonlinear optical model of the cavity-condensate system is developed
under Discrete Mode Approximation (DMA), while matter-field coupling has been
considered beyond the Rotating Wave Approximation. By analytical and numerical
solutions of the nonlinear dynamical equations, we examine the mean cavity
field and population difference (magnetization) of the condensate modes. The
stationary solutions of both the mean cavity field and normalized magnetization
demonstrate bistable behavior under certain conditions for the laser pump
intensity and matter-field coupling strength.Comment: Proceeding of Laser Physics 201
On quantifying fault patterns of the mesh interconnect networks
One of the key issues in the design of Multiprocessors System-on-Chip (MP-SoCs), multicomputers, and peerto- peer networks is the development of an efficient communication network to provide high throughput and low latency and its ability to survive beyond the failure of individual components. Generally, the faulty components may be coalesced into fault regions, which are classified into convex and concave shapes. In this paper, we propose a mathematical solution for counting the number of common fault patterns in a 2-D mesh interconnect network including both convex (|-shape, | |-shape, ý-shape) and concave (L-shape, Ushape, T-shape, +-shape, H-shape) regions. The results presented in this paper which have been validated through simulation experiments can play a key role when studying, particularly, the performance analysis of fault-tolerant routing algorithms and measure of a network fault-tolerance expressed as the probability of a disconnection
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Robust search-free car number plate localization incorporating hierarchical saliency
There are two major shortcomings associated with presently implemented automatic license plate recognition (ALPR) systems: first, processing images with complex background is time-consuming and second, the results are not sufficiently accurate. To overcome these problems and also to achieve a robust recognition of multiple car number plates, saliency detection based on the ALPR system is used in this paper and also an improved and more effective definition of saliency is presented. In this new approach, the notion of the directionality of the edges using Gabor filtering and the detection of the patterns of numbers using L1 -norm have been added to the traditional saliency detection method. The proposed algorithm was tested on 660 images; some consisting of two or more cars.
A detection accuracy of 94.77% and an average execution time of 40 ms for 600 × 800 images are the marked outcomes. The proposed SB-ALPR method outperforms most of the state of the art techniques in terms of execution time and accuracy, and can be used in real-time applications. Also, unlike some recently introduced saliency-based ALPR methods, our two-stage saliency detection approach exploits smaller numbers of sample sizes to reduce the computation cost
Incorporating negentropy in saliency-based search free car number plate localization
License plate localization algorithms aim to detect license plates within the scene. In this paper, a new algorithm is discussed where the necessary conditions are imposed into the saliency detection equations. Measures of distance between probability distributions such as negentropy finds the candidate license plates in the image and the Bayesian methodology exploits the a priori information to estimate the highest probability for each candidate. The proposed algorithm has been tested for three datasets, consisting of gray-scale and color images. A detection accuracy of 96% and an average execution time of 80 ms for the first dataset are the marked outcomes. The proposed method outperforms most of the state-of-the-art techniques and it is suitable to use in real-time ALPR applications
Catalase epitopes vaccine design for Helicobacter pylori: A bioinformatics approach
Bioinformatics tools are helpful for epitopes prediction directly from the genomes of pathogens in order to design a vaccine. Epitopes are sub-sequences of proteins (8 to 10 mer peptides) which bind to MHC to interact with the T cell receptors and stimulate immune responses. Finding a suitable vaccine against Helicobacter pylori is necessary, because of high prevalence of the infection (25 to 90%). Moreover, this bacteria has been classified as a grade I carcinogen by WHO since 1994. Catalase, an important enzyme in the virulence of H. pylori, could be a suitable candidate for vaccine design because it is highly conserved, which is important for the survival of H. pylori; it is expressed in high level and it is exposed on the surface of the bacteria. In this study, we designed epitope-based vaccine for catalase specific regions of H. pylori by means of immunobioinformatic tools. H. pylori (26695) catalase has been compared with human catalase in order to select specific regions. Afterwards, epitopes of catalase were determined by propred software. Among predicted epitopes, three epitopes were selected including, MVNKDVKQTT, VLLQSTWFL and FHPFDVTKI. Three candidates out of 51catalase antigen epitopes had the highest score for reactivating with MHC II MHC in propred software. The candidate epitopes for vaccine design should be rather a composition of considering epitopes: MVNKDVKQTTKKVLLQSTWFLKKFHPFDVTKI. In this manner, 39 of 51 alleles of MHC class ІІ were involved and stimulated T-cell responses. We believe prediction of catalase epitopes by the immunoinformatics tools would be valuable for developing new immuoprophylatic strategy against H. pylori infection.Key words: Helicobacter pylori, catalase, epitopes
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