3,179 research outputs found

    Image Enhancement via Extrapolation Techniques: A Two Dimensional Iterative Scheme a Direct Matrix Inversion Scheme

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    In [1] and [2], we have developed a model and three dimensional inversion algorithm for detecting flaw in structures. The model, based on rigorous electromagnetic theory, and the algorithm have as their main objective the high resolution imaging of the flaw. The algorithm is computationally intensive and, like other inversion techniques, involves the solution of some ill conditioned problems

    Cancer and systemic inflammation: treat the tumour and treat the host

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    Determinants of cancer progression and survival are multifactorial and host responses are increasingly appreciated to have a major role. Indeed, the development and maintenance of a systemic inflammatory response has been consistently observed to confer poorer outcome, in both early and advanced stage disease. For patients, cancer-associated symptoms are of particular importance resulting in a marked impact on day-to-day quality of life and are also associated with poorer outcome. These symptoms are now recognised to cluster with one another with anorexia, weight loss and physical function forming a recognised cluster whereas fatigue, pain and depression forming another. Importantly, it has become apparent that these symptom clusters are associated with presence of a systemic inflammatory response in the patient with cancer. Given the understanding of the above, there is now a need to intervene to moderate systemic inflammatory responses, where present. In this context the rationale for therapeutic intervention using nonselective anti-inflammatory agents is clear and compelling and likely to become a part of routine clinical practice in the near future. The published literature on therapeutic intervention using anti-inflammatory agents for cancer-associated symptoms was reviewed. There are important parallels with the development of useful treatments for the systemic inflammatory response in patients with rheumatological disease and cardiovascular disease

    Spectral weight transfer in a disorder-broadened Landau level

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    In the absence of disorder, the degeneracy of a Landau level (LL) is N=BA/Ď•0N=BA/\phi_0, where BB is the magnetic field, AA is the area of the sample and Ď•0=h/e\phi_0=h/e is the magnetic flux quantum. With disorder, localized states appear at the top and bottom of the broadened LL, while states in the center of the LL (the critical region) remain delocalized. This well-known phenomenology is sufficient to explain most aspects of the Integer Quantum Hall Effect (IQHE) [1]. One unnoticed issue is where the new states appear as the magnetic field is increased. Here we demonstrate that they appear predominantly inside the critical region. This leads to a certain ``spectral ordering'' of the localized states that explains the stripes observed in measurements of the local inverse compressibility [2-3], of two-terminal conductance [4], and of Hall and longitudinal resistances [5] without invoking interactions as done in previous work [6-8].Comment: 5 pages 3 figure

    Fractional quantum Hall effect in the absence of Landau levels

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    It has been well-known that topological phenomena with fractional excitations, i.e., the fractional quantum Hall effect (FQHE) \cite{Tsui1982} will emerge when electrons move in Landau levels. In this letter, we report the discovery of the FQHE in the absence of Landau levels in an interacting fermion model. The non-interacting part of our Hamiltonian is the recently proposed topologically nontrivial flat band model on the checkerboard lattice \cite{sun}. In the presence of nearest-neighboring repulsion (UU), we find that at 1/3 filling, the Fermi-liquid state is unstable towards FQHE. At 1/5 filling, however, a next-nearest-neighboring repulsion is needed for the occurrence of the 1/5 FQHE when UU is not too strong. We demonstrate the characteristic features of these novel states and determine the phase diagram correspondingly.Comment: 6 pages and 4 figure

    Observation of the Fractional Quantum Hall Effect in Graphene

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    When electrons are confined in two dimensions and subjected to strong magnetic fields, the Coulomb interactions between them become dominant and can lead to novel states of matter such as fractional quantum Hall liquids. In these liquids electrons linked to magnetic flux quanta form complex composite quasipartices, which are manifested in the quantization of the Hall conductivity as rational fractions of the conductance quantum. The recent experimental discovery of an anomalous integer quantum Hall effect in graphene has opened up a new avenue in the study of correlated 2D electronic systems, in which the interacting electron wavefunctions are those of massless chiral fermions. However, due to the prevailing disorder, graphene has thus far exhibited only weak signatures of correlated electron phenomena, despite concerted experimental efforts and intense theoretical interest. Here, we report the observation of the fractional quantum Hall effect in ultraclean suspended graphene, supporting the existence of strongly correlated electron states in the presence of a magnetic field. In addition, at low carrier density graphene becomes an insulator with an energy gap tunable by magnetic field. These newly discovered quantum states offer the opportunity to study a new state of matter of strongly correlated Dirac fermions in the presence of large magnetic fields

    Multicomponent fractional quantum Hall effect in graphene

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    We report observation of the fractional quantum Hall effect (FQHE) in high mobility multi-terminal graphene devices, fabricated on a single crystal boron nitride substrate. We observe an unexpected hierarchy in the emergent FQHE states that may be explained by strongly interacting composite Fermions with full SU(4) symmetric underlying degrees of freedom. The FQHE gaps are measured from temperature dependent transport to be up 10 times larger than in any other semiconductor system. The remarkable strength and unusual hierarcy of the FQHE described here provides a unique opportunity to probe correlated behavior in the presence of expanded quantum degrees of freedom.Comment: 5 pages, 3 figure

    Garment smoothness appearance evaluation through computer vision

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    The measurement and evaluation of the appearance of wrinkling in textile products after domestic washing and drying is performed currently by the comparison of the fabric with the replicas. This kind of evaluation has certain drawbacks, the most significant of which are its subjectivity and its limitations when used with garments. In this paper, we present an automated wrinkling evaluation system. The system developed can process fabrics as well as any type of garment, independent of size or pattern on the material. The system allows us to label different parts of the garment. Thus, as different garment parts have different influence on human perception, this labeling enables the use of weighting, to improve the correlation with the human visual system. The system has been tested with different garments showing good performance and correlation with human perception. © The Author(s) 2012.Silvestre-Blanes, J.; Berenguer Sebastiá, JR.; Pérez Llorens, R.; Miralles, I.; Moreno Canton, J. (2012). Garment smoothness appearance evaluation through computer vision. Textile Research Journal. 82(3):299-309. doi:10.1177/0040517511424530S299309823López, F., Miguel Valiente, J., Manuel Prats, J., & Ferrer, A. (2008). Performance evaluation of soft color texture descriptors for surface grading using experimental design and logistic regression. Pattern Recognition, 41(5), 1744-1755. doi:10.1016/j.patcog.2007.09.011Villette, S. (2008). Simple imaging system to measure velocity and improve the quality of fertilizer spreading in agriculture. Journal of Electronic Imaging, 17(3), 031109. doi:10.1117/1.2956835Neri, F., & Tirronen, V. (2009). Memetic Differential Evolution Frameworks in Filter Design for Defect Detection in Paper Production. Studies in Computational Intelligence, 113-131. doi:10.1007/978-3-642-01636-3_7Carfagni, M., Furferi, R., & Governi, L. (2005). A real-time machine-vision system for monitoring the textile raising process. Computers in Industry, 56(8-9), 831-842. doi:10.1016/j.compind.2005.05.010Wang, W., Wong, Y. S., & Hong, G. S. (2005). Flank wear measurement by successive image analysis. Computers in Industry, 56(8-9), 816-830. doi:10.1016/j.compind.2005.05.009Cho, C.-S., Chung, B.-M., & Park, M.-J. (2005). Development of Real-Time Vision-Based Fabric Inspection System. IEEE Transactions on Industrial Electronics, 52(4), 1073-1079. doi:10.1109/tie.2005.851648Kawabata, S., Mori, M., & Niwa, M. (1997). An experiment on human sensory measurement and its objective measurement. International Journal of Clothing Science and Technology, 9(3), 203-206. doi:10.1108/09556229710168324Fan, J., Lu, D., Macalpine, J. M. K., & Hui, C. L. P. (1999). Objective Evaluation of Pucker in Three-Dimensional Garment Seams. Textile Research Journal, 69(7), 467-472. doi:10.1177/004051759906900701Fan, J., & Liu, F. (2000). Objective Evaluation of Garment Seams Using 3D Laser Scanning Technology. Textile Research Journal, 70(11), 1025-1030. doi:10.1177/004051750007001114Yang, X. B., & Huang, X. B. (2003). Evaluating Fabric Wrinkle Degree with a Photometric Stereo Method. Textile Research Journal, 73(5), 451-454. doi:10.1177/004051750307300513Kang, T. J., Kim, S. C., Sul, I. H., Youn, J. R., & Chung, K. (2005). Fabric Surface Roughness Evaluation Using Wavelet-Fractal Method. Textile Research Journal, 75(11), 751-760. doi:10.1177/0040517505058855Mohri, M., Ravandi, S. A. H., & Youssefi, M. (2005). Objective evaluation of wrinkled fabric using radon transform. Journal of the Textile Institute, 96(6), 365-370. doi:10.1533/joti.2004.0066Zaouali, R., Msahli, S., El Abed, B., & Sakli, F. (2007). Objective evaluation of multidirectional fabric wrinkling using image analysis. Journal of the Textile Institute, 98(5), 443-451. doi:10.1080/00405000701489156Yu, W., Yao, M., & Xu, B. (2009). 3-D Surface Reconstruction and Evaluation of Wrinkled Fabrics by Stereo Vision. Textile Research Journal, 79(1), 36-46. doi:10.1177/004051750809049
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