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51.
Kwon BJ Perry TT Wilhelm CL Healy EW 《The Journal of the Acoustical Society of America》2012,131(4):3111-3119
Normal-hearing (NH) listeners maintain robust speech understanding in modulated noise by "glimpsing" portions of speech from a partially masked waveform--a phenomenon known as masking release (MR). Cochlear implant (CI) users, however, generally lack such resiliency. In previous studies, temporal masking of speech by noise occurred randomly, obscuring to what degree MR is attributable to the temporal overlap of speech and masker. In the present study, masker conditions were constructed to either promote (+MR) or suppress (-MR) masking release by controlling the degree of temporal overlap. Sentence recognition was measured in 14 CI subjects and 22 young-adult NH subjects. Normal-hearing subjects showed large amounts of masking release in the +MR condition and a marked difference between +MR and -MR conditions. In contrast, CI subjects demonstrated less effect of MR overall, and some displayed modulation interference as reflected by poorer performance in modulated maskers. These results suggest that the poor performance of typical CI users in noise might be accounted for by factors that extend beyond peripheral masking, such as reduced segmental boundaries between syllables or words. Encouragingly, the best CI users tested here could take advantage of masker fluctuations to better segregate the speech from the background. 相似文献
52.
Leader-following consensus criteria for multi-agent systems with time-varying delays and switching interconnection topologies 下载免费PDF全文
We consider multi-agent systems with time-varying delays and switching interconnection topologies.By constructing a suitable Lyapunov-Krasovskii functional and using the reciprocally convex approach,new delay-dependent consensus criteria for the systems are established in terms of linear matrix inequalities(LMIs),which can be easily solved by using various effective optimization algorithms.Two numerical examples are given to illustrate the effectiveness of the proposed methods. 相似文献
53.
We present a microscopic quantum theoretical analysis of the nanoscale superfluid properties of solvating clusters of para-H2 around the linear OCS molecule. Path-integral calculations with N=17 para-H2 molecules, constituting a full solvation shell, show the appearance of a significant superfluid response to rotation around the molecular axis at T=0.15 K. This low-temperature superfluid response is highly anisotropic and drops sharply as the temperature increases to T approximately 0.3 K. These calculations provide definitive theoretical evidence that an anisotropic superfluid state exists for molecular hydrogen in this microscopic solvation layer. 相似文献
54.
Sungchil Kang Alexander Efremov Sun Jin Yun Jinyoung Son Kwang-Ho Kwon 《Plasma Chemistry and Plasma Processing》2013,33(2):527-538
An investigation of etching behaviors for Mo and Al2O3 thin films in O2/Cl2/Ar inductively coupled plasmas at constant gas pressure (6 mTorr), input power (700 W) and bias power (200 W) was carried out. It was found that an increase in Ar mixing ratio for Cl2/Ar plasma results in non-monotonic etching rates with the maximums of 160 nm/min at 60 % Ar for Mo and 27 nm/min at 20 % Ar for Al2O3. The addition of O2 in the Cl2/Ar plasma causes the non-monotonic Mo etching rate (max. 320 nm/min at 40–45 % O2) while the Al2O3 etching rate decreases monotonically. The model-based analysis of etching kinetics allows one to relate the non-monotonic etching rates in Cl2/Ar plasma to the change in the etching regime from the ion-flux-limited mode (at low Ar mixing ratios) to the neutral-flux-limited mode (for high Ar mixing ratios). In the Cl2/O2/Ar plasma, the non-monotonic Mo etching rate is probably due to the change in reaction probability. 相似文献
55.
This study was conducted to examine the anti-hair loss mechanism of the supercritical fluid extraction-residues extract of Ulmus davidiana by the regulation of cytokine production and hormone function in human dermal follicle papilla cells (HDFPCs). To investigate the modulatory effects on H2O2-induced cytokines, we measured transforming growth factor-beta and insulin-like growth factor 1 secreted from HDFPCs. To investigate the regulatory effects of supercritical extraction-residues extract of Ulmus davidiana on dihydrotestosterone hormone production, cells were co-incubated with high concentrations of testosterone. The supercritical extraction-residues extract of Ulmus davidiana significantly inhibited the secretion of transforming growth factor-beta but rescued insulin-like growth factor 1 in a dose-dependent manner. The supercritical extraction-residues extract of Ulmus davidiana markedly reduced dihydrotestosterone production. These results suggest that the supercritical fluid extract residues of Ulmus davidiana and their functional molecules are candidates for preventing human hair loss. 相似文献
56.
O-Kab Kwon Dongmin Jang Yoonbai Kim D. D. Tolla 《The European Physical Journal C - Particles and Fields》2018,78(10):856
We investigate the gauge/gravity duality between the \(\mathcal{N} = 6\) mass-deformed ABJM theory with \(\hbox {U}_k(N)\times \hbox {U}_{-k}(N)\) gauge symmetry and the 11-dimensional supergravity on LLM geometries with SO(2,1)\(\times \)SO(4)/\({\mathbb {Z}}_k\) \(\times \)SO(4)/\({\mathbb {Z}}_k\) isometry, in terms of a KK holography, which involves quadratic order field redefinitions. We establish the quadratic order KK mappings for various gauge invariant fields in order to obtain the canonical 4-dimensional gravity equations of motion and to reduce the LLM solutions to an asymptotically AdS\(_4\) gravity solutions. The non-linearity of the KK maps indicates that we can observe the true purpose of the non-linear KK holography of the LLM solutions. We read the vacuum expectation value of conformal dimension two operator from the asymptotically AdS\(_4\) gravity solutions. For the LLM solutions which are represented by square-shaped Young diagrams, we compare the vacuum expectation value obtained from the holographic procedure with the result obtained from the field theory, which is given by \(\langle \mathcal{O}^{(\Delta =2)}\rangle =\sqrt{k}N^{\frac{3}{2}}f_{(\Delta =2)}+\mathcal{O}(N)\), where \(f_{\Delta }\) is independent of N. Based on this result, we examine the gauge/gravity duality in the large N limit and finite k. We also show that the vacuum expectation values of the massive KK graviton modes are vanishing as expected by the supersymmetry. 相似文献
57.
We investigated the transverse beam dynamics in a thermal wave model by using a functional method. It can describe the beam optical elements separately with a kernel for a component. The method can be applied to general quadrupole magnets beyond a thin lens approximation as well as drift spaces. We found that the model can successfully describe the PARMILA simulation result through an FODO lattice structure for the Gaussian input beam without space charge effects. 相似文献
58.
Im HJ Ito T Kim HD Kimura S Lee KE Hong JB Kwon YS Yasui A Yamagami H 《Physical review letters》2008,100(17):176402
Ce 4d-4f resonant angle-resolved photoemission spectroscopy was carried out to study the electronic structure of strongly correlated Ce 4f electrons in a quasi-two-dimensional nonmagnetic heavy-fermion system CeCoGe1.2Si0.8. For the first time, dispersive coherent peaks of an f state crossing the Fermi level, the so-called Kondo resonance, are directly observed together with the hybridized conduction band. Moreover, the experimental band dispersion is quantitatively in good agreement with a simple hybridization-band picture based on the periodic Anderson model. The obtained physical quantities, i.e., coherent temperature, Kondo temperature, and mass enhancement, are comparable to the results of thermodynamic measurements. These results manifest an itinerant nature of Ce 4f electrons in heavy-fermion systems and clarify their microscopic hybridization mechanism. 相似文献
59.
The carbamoylphosphosphonate silane (CMPO analogue; 2-(diphenylphosphoryl)-N-(3-(triethoxysilyl)propyl) acetamide) modified mesoporous silica was prepared via a post-synthesis grafting method for the effective purification of rare earth elements. The guest CMPO analogue was synthesized by direct coupling reaction of 2-(diphenylphosphoryl) acetic acid and 3-(triethoxysilyl)propan-1-amine. Various mesoporous silicates such as MCM-41, SBA-15, or amorphous silica nanoparticles were adopted as host materials. The resulting surface-modified mesoporous materials were characterized with respect to their structural integrity, surface area, and pore size and the concentration of the CMPO silane species. These CMPO functionalized periodic mesostructured silicates offer the potential of applications as catalysts, sensors, or environmental sorbents. 相似文献
60.
Kyeongnan Kwon 《Journal of Dispersion Science and Technology》2016,37(10):1518-1525
Glucose-responsive monoolein (MO) cubic phase was prepared by immobilizing proteinoid composed of Asp and Leu (PAL) and hydrophobically modified glucose oxidase (HmGOD) onto the MO bilayers. The hydrodynamic mean diameter of PAL aggregate in aqueous solution decreased with increasing the pH value. The number of pamitic acid residue per one molecule of HmGOD was determined to be 6.3 by a calorimetric method. HmGOD could acidify glucose solution in a few hours, possibly because it converted glucose to gluconic acid. PAL- and HmGOD-immobilized MO cubic phase was prepared by hydrating MO melt with the mixture aqueous solution of PAL and HmGOD. The cubic phase exhibited its phase transition around 62.5°C, determined by polarizing microscopy. The release of carboxylic fluorescein (CF) from the cubic phase was suppressed when the pH value of release medium decreased, possibly because PAL can aggregate more at a lower pH value. The release was suppressed when glucose concentration increased, possibly because the release medium can be more acidified and PAL will be more aggregated at a higher glucose concentration. The cubic phase could be used as a drug carrier which releases its content in a sustained manner when the glucose concentration is abnormally high. 相似文献