1,230 research outputs found

    Modeling tidal current around Mokpo, the South Western coastal zone of Korea

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    This study provide modeling of tidal circulation around the Mokpo coastal zone (MC) using unstructured triangular horizontal grid by which high resolution is concentrated in the local region that reaches to 100 m. For this simulation, the 3D finite-volume ocean model FVCOM is applied for the numerical simulation. Only the astronomical tidal constituent M2 and its harmonic M4 are considered. By expanding open boundary to the shelf break of the East China Sea, only M2 elevation was specified on the open boundaries, and the generation of M4 tide around MC was observed, which is the representative criteria for the accuracy of the shallow water tide simulation. Around the intertidal zone of MC, wet/dry point treatment method incorporated in FVCOM was also used and tested its applicability in the level of resolution of this model

    Bacteria Hunt: A multimodal, multiparadigm BCI game

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    Brain-Computer Interfaces (BCIs) allow users to control applications by brain activity. Among their possible applications for non-disabled people, games are promising candidates. BCIs can enrich game play by the mental and affective state information they contain. During the eNTERFACE’09 workshop we developed the Bacteria Hunt game which can be played by keyboard and BCI, using SSVEP and relative alpha power. We conducted experiments in order to investigate what difference positive vs. negative neurofeedback would have on subjects’ relaxation states and how well the different BCI paradigms can be used together. We observed no significant difference in mean alpha band power, thus relaxation, and in user experience between the games applying positive and negative feedback. We also found that alpha power before SSVEP stimulation was significantly higher than alpha power during SSVEP stimulation indicating that there is some interference between the two BCI paradigms

    Cluster persistence in one-dimensional diffusion--limited cluster--cluster aggregation

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    The persistence probability, PC(t)P_C(t), of a cluster to remain unaggregated is studied in cluster-cluster aggregation, when the diffusion coefficient of a cluster depends on its size ss as D(s)sγD(s) \sim s^\gamma. In the mean-field the problem maps to the survival of three annihilating random walkers with time-dependent noise correlations. For γ0\gamma \ge 0 the motion of persistent clusters becomes asymptotically irrelevant and the mean-field theory provides a correct description. For γ<0\gamma < 0 the spatial fluctuations remain relevant and the persistence probability is overestimated by the random walk theory. The decay of persistence determines the small size tail of the cluster size distribution. For 0<γ<20 < \gamma < 2 the distribution is flat and, surprisingly, independent of γ\gamma.Comment: 11 pages, 6 figures, RevTeX4, submitted to Phys. Rev.

    Fano resonance in electronic transport through a quantum wire with a side-coupled quantum dot: X-boson treatment

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    The transport through a quantum wire with a side coupled quantum dot is studied. We use the X-boson treatment for the Anderson single impurity model in the limit of U=U=\infty . The conductance presents a minimum for values of T=0 in the crossover from mixed-valence to Kondo regime due to a destructive interference between the ballistic channel associated with the quantum wire and the quantum dot channel. We obtain the experimentally studied Fano behavior of the resonance. The conductance as a function of temperature exhibits a logarithmic and universal behavior, that agrees with recent experimental results.Comment: 6 pages, 10 eps figs., revtex

    Quantum railroads and directed localization at the juncture of quantum Hall systems

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    The integer quantum Hall effect (QHE) and one-dimensional Anderson localization (AL) are limiting special cases of a more general phenomenon, directed localization (DL), predicted to occur in disordered one-dimensional wave guides called "quantum railroads" (QRR). Here we explain the surprising results of recent measurements by Kang et al. [Nature 403, 59 (2000)] of electron transfer between edges of two-dimensional electron systems and identify experimental evidence of QRR's in the general, but until now entirely theoretical, DL regime that unifies the QHE and AL. We propose direct experimental tests of our theory.Comment: 11 pages revtex + 3 jpeg figures, to appear in Phys. Rev.

    Charged-Lepton-Flavour Violation in the CMSSM in View of the Muon Anomalous Magnetic Moment

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    We use the BNL E821 measurement of g - 2, the anomalous magnetic moment of the muon, to normalize, within a supersymmetric GUT framework, constrained MSSM (CMSSM) predictions for processes that violate charged-lepton flavour conservation, including mu to e gamma, mu to e conversion and K^0_L to mu e. We illustrate our analysis with two examples of lepton mass matrix textures motivated by data on neutrino oscillations. We find that mu to e gamma may well occur at a rate within one or two (two or three) orders of magnitude of the present experimental upper limit if g - 2 is within the one- (two-)standard deviation range indicated by E821. We also find that mu to e conversion is likely to occur at rate measurable by MECO, and there is a chance that K^0_L to mu e may be observable in an experiment using an intense proton source.Comment: 14 pages, 3 eps figure

    Curie temperature enhancement of electron doped Sr2_2FeMoO6_6 perovskites studied by photoemission spectroscopy

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    We report here on the electronic structure of electron-doped half-metallic ferromagnetic perovskites such Sr2x_{2-x}Lax_xFeMoO6_6 (xx=0-0.6) as obtained from high-resolved valence-band photoemission spectroscopy (PES). By comparing the PES spectra with band structure calculations, a distinctive peak at the Fermi level (EF_F) with predominantly (Fe+Mo) t2g_{2g}^\downarrow character has been evidenced for all samples, irrespectively of the xx values investigated. Moreover, we show that the electron doping due to the La substitution provides selectively delocalized carriers to the t2g_{2g}^\downarrow metallic spin channel. Consequently, a gradual rising of the density of states at the EF_F has been observed as a function of the La doping. By changing the incoming photon energy we have shown that electron doping mainly rises the density of states of Mo parentage. These findings provide fundamental clues for understanding the origin of ferromagnetism in these oxides and shall be of relevance for tailoring oxides having still higher TC_C

    Identification of a putative protein-profile associating with tamoxifen therapy-resistance in breast cancer

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    Tamoxifen-resistance is a major cause of death in patients with recurrent breast cancer. Current clinical parameters can correctly predict therapy response in only half of the treated patients. Identification of proteins that associate with tamoxifen-resistance is a first step towards better response prediction and tailored treatment of patients. In the present study we aimed to identify putative protein biomarkers indicative of tamoxifen therapy-resistance in breast cancer, using nanoLC-FTICR MS. Comparative proteome analysis was performed on ~5,500 pooled tumor cells obtained through laser capture microdissection from two independently processed data sets (n=24 and n=27) of tamoxifen therapy-sensitive and -resistant tumors. Peptide and protein identifications were acquired by matching mass and elution time features to information in previously generated accurate mass and time tag reference data bases. A total of 17,263 unique peptides were identified that corresponded to 2,556 non-redundant proteins identified with >=2 peptides. From this total, 1,713 protein

    Persistence properties of a system of coagulating and annihilating random walkers

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    We study a d-dimensional system of diffusing particles that on contact either annihilate with probability 1/(q-1) or coagulate with probability (q-2)/(q-1). In 1-dimension, the system models the zero temperature Glauber dynamics of domain walls in the q-state Potts model. We calculate P(m,t), the probability that a randomly chosen lattice site contains a particle whose ancestors have undergone exactly (m-1) coagulations. Using perturbative renormalization group analysis for d < 2, we show that, if the number of coagulations m is much less than the typical number M(t), then P(m,t) ~ m^(z/d) t^(-theta), with theta=d Q + Q(Q-1/2) epsilon + O(epsilon^2), z=(2Q-1) epsilon + (2 Q-1) (Q-1)(1/2+A Q) epsilon^2 +O(epsilon^3), where Q=(q-1)/q, epsilon =2-d and A =-0.006. M(t) is shown to scale as t^(d/2-delta), where delta = d (1 -Q)+(Q-1)(Q-1/2) epsilon+ O(epsilon^2). In two dimensions, we show that P(m,t) ~ ln(t)^(Q(3-2Q)) ln(m)^((2Q-1)^2) t^(-2Q) for m << t^(2 Q-1). The 1-dimensional results corresponding to epsilon=1 are compared with results from Monte Carlo simulations.Comment: 12 pages, revtex, 5 figure

    Complementarity of Galactic radio and collider data in constraining WIMP dark matter models

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    In this work we confront dark matter models to constraints that may be derived from radio synchrotron radiation from the Galaxy, taking into account the astrophysical uncertainties and we compare these to bounds set by accelerator and complementary indirect dark matter searches. Specifically we apply our analysis to three popular particle physics models. First, a generic effective operator approach, in which case we set bounds on the corresponding mass scale, and then, two specific UV completions, the Z' and Higgs portals. We show that for many candidates, the radio synchrotron limits are competitive with the other searches, and could even give the strongest constraints (as of today) with some reasonable assumptions regarding the astrophysical uncertainties.Comment: 22 pages, 12 figure
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