Acoustic Cue Weighting in Children Wearing Cochlear Implants

The purpose of this study was to determine how normal hearing adults (NHA), normal hearing children (NHC) and children wearing cochlear implants (CI) differ in the perceptual weight given cues for fricative consonant and voiceless stop consonant continua. Ten normal-hearing adults (NHA), eleven 5-8-year-old normalhearing children (NHC) and eight 5-8-year-old children wearing cochlear implants (CI) were participants. For fricative consonant perception, the /su/-/∫u/ continua were constructed by varying a fricative spectrum cue in three steps and by varying a F2 onset transition cue in three steps. For voiceless stop consonant perception, the /pu/- /tu/ continua were constructed by varying a burst cue in three steps and a F2 onset transition cue in three steps. A quantitative method of analysis (ANOVA model) was used to determine cue weighting and measure cue interaction. For the fricative consonant, both NHC and NHA gave more perceptual weight to the frication spectral cue than to the formant transition. NHC gave significantly less weight to the fricative spectrum cue than NHA. The weight given the transition cue was similar for NHC and NHA, and the degree of cue interaction was similar between two groups. The CI group gave more perceptual weight to the fricative spectrum cue than to the transition. The degree of cue interaction was not significant for CI. For the voiceless stop consonant, both NHC and NHA gave more perceptual weight to the transition cue than to the burst cue. NHC gave proportionately less weight to the transition cue than NHA. The weight given the burst cue and the degree of cue interaction were similar between NHC and NHA. The CI group gave more perceptual weight to the transition cue than to the burst cue, and there was no significant difference between children wearing cochlear implants and normal hearing children group; however, the degree of cue interaction was not significant for CI. These results indicated that all groups favored the longer-duration cue to make phonemic judgments. Also there were developmental patterns. The CI group has similar cue weighting strategies to agematched NHC, but the integration of the cues was not significant for either fricative or voiceless stop consonant perception

Are Broker Quotes Too Optimistic? Korean Evidence

We examine the behavior of broker quotes in Korean housing markets by comparing the Kookmin Bank apartment (a condominium in a high- rise residential building) price index, a broker quote based apartment price index, and a repeat sales apartment price index that we built using transaction prices, which have become available since January 2006. Broker quotes may differ from actual prices depending on the housing market conditions. Specifically, we test the hypotheses: (1) price increases shown by the broker quote based apartment price index are greater than those shown by the repeat sales apartment price index in an up market; and (2) the broker quote based price index shows a far less price reduction than the repeat sales price index in a down market. We find that indeed in a down market, the broker quote based price index shows far less price reduction than the repeat sales price index (5.75%-8.07%). However, the broker quote based price index does not distort the prices in an up market, where trading volumes are high. It appears that the price inflation in the broker quotes rises as the transaction volume drops. While broker quotes are substantially higher than transaction prices in a down market, the broker sentiment, which is a qualitative assessment of market conditions, appears to be more in line with transaction prices. We have also documented that the broker quote based index reaches its peak about two months after the peak of the repeat sales based index. Finally, broker quotes are smooth in comparison to transaction prices and they are smoothed more in a down market than an up market. Our results suggest that an optimistic view of broker quotes is problematic only in down markets where trading volumes are limited. The price inflation in broker quotes is a risk to the financial system in a market with only a broker quote based index in that it overstates the collateral values underlying mortgage loans in a down market.Broker quotes; Broker quote based apartment price index; Repeat sales apartment price index; House price cycle; Broker sentiment; Korean housing markets

Patterns of Capital Structure Adjustment by Listing Type: Evidence from European Firms

Abstrac

Photoelectric spectrophotometry of Wolf-Rayet stars

Photoelectric spectrum scans of five southern Wolf-Rayet stars in the spectral range lambda lambda 4600-4720 were analyzed to study the variability of brightness and of emission line strengths. No variations of any kind in short time scale were found. However, in WC stars night-to-night variations of three to four percent were detected in the emission line strengths

The Y-Band at 1.035 um: Photometric Calibration and the Dwarf Stellar/Sub-Stellar Color Sequence

We define and characterize a photometric bandpass (called "Y") that is centered at 1.035 um, in between the traditionally classified ``optical'' and ``infrared'' spectral regimes. We present Y magnitudes and Y-H and Y-K colors for a sample consisting mostly of photometric and spectral standards, spanning the spectral type range sdO to T5V. Deep molecular absorption features in the near-infrared spectra of extremely cool objects are such that the Y-H and Y-K colors grow rapidly with advancing spectral type especially from late M through mid L, substantially more rapidly than J-H or H-K which span a smaller total dynamic range. Consistent with other near-infrared colors, however, Y-H and Y-K colors turn blueward in the L6-L8 temperature range with later T-type objects having colors similar to those of warmer M and L stars. Use of the Y-band filter is nonetheless promising for easy identification of low-mass stars and brown dwarfs, especially at young ages. The slope of the interstellar reddening vector within this filter is A_Y = 0.38 x A_V. Reddening moves stars nearly along the YHK dwarf color sequence making it more difficult to distinguish unambiguously very low mass candidate brown dwarf objects from higher mass stars seen, e.g. through the galactic plane or towards star-forming regions. Other diagrams involving the Y-band may be somewhat more discriminating.Comment: accepted at PAS

Altering Physical Properties of Particles with Surface Roughness - Anomalous Properties of 'Hedgehog' Particles.

Particles are ubiquitous and are integral components of modern technology. Sensitive to any alterations or even a small perturbation in its constitutive properties, sizes and shapes, particles have been utilized as a versatile means in a compact platform with which to manipulate, enhance or transform any physico-chemical properties in its environment. Amongst the variety, procedural and synthetic diversities and accompanying investigation of the physical and chemical properties of micron-scale particles having highly rough surfaces is barren in previous studies. Yet, most of the particles found in nature are “rough” particles. Therefore, a thorough survey that maps the deviation in properties from what is expected of standard predictions from analytically “smooth” particles, accompanied by systematic analysis protocols, is expected bring a broad impact to multiple scientific and practical disciplines. In the early phase of the research as a precursor to the construction of “rough” particles, the focus was on the synthesis of smooth polymeric microspheres. As microspheres had been extensively characterized, the focus was on the development and streamlining of large-scale fabrication process based on microfluidics setup. The second phase of the research involved the synthesis and characterization of “rough” particles having orthogonal orientation of high aspect ratio ZnO nanospikes on polymeric microspheres, which we called the ‘hedgehog’ particles to reflect its morphology. In this phase, we studied the ‘hedgehog’ particles in a colloidal system and report an anomalous colloidal dispersion behavior Lastly, owing to unique geometrical and material configurations, the ‘hedgehog’ particles enabled us to study electromagnetic response of “rough” particles, where all of its photonic compartments are dielectric and lie within the Mie scattering regime. Here, we showed that the presence of surface roughness alters the electromagnetic responses from what would have been expected of typical micron-scale dielectric particles. These studies are only a small subset of synthetic and property diversities possible with “rough” particle configurations. We believe that continued investigation and further expansion in the knowledge of “rough”, as well as particles of other configurations, may enable us a spectrum of design possibilities for realizing high performance substrates and devices.PHDBiomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/135736/1/joonghb_1.pd

Reductive dechlorination of chlorinated aliphatic hydrocarbons by Fe(ii) in degradative solidification/stabilization

This dissertation examines the applicability of the iron-based degradative solidification/stabilization (DS/S-Fe(II)) to various chlorinated aliphatic hydrocarbons (CAHs) that are common chemicals of concern at contaminated sites. The research focuses on the transformation of 1,1,1-trichloroethane (1,1,1-TCA), 1,1,2,2-tetrachloro-ethane (1,1,2,2-TetCA) and 1,2-dichloroehtane (1,2-DCA) by Fe(II) in cement slurries. It also investigates the degradation of 1,1,1-TCA by a mixture of Fe(II), cement and three iron-bearing phyllosilicates. Transformation of 1,1,1-TCA and 1,1,2,2-TetCA by Fe(II) in 10% cement slurries was characterized using batch reactors. Dechlorination kinetics of 1,1,1-TCA and TCE* (TCE that was produced by transformation of 1,1,2,2-TetCA) was strongly dependent on Fe(II) dose, pH and initial target organic concentration. Degradation of target organics in DS/S-Fe(II) process was generally described by a pseudo-first-order rate law. However, saturation relationships between the rate constants and Fe(II) dose or between the initial degradation rates and target organic concentration were observed. These behaviors were properly described by a modified Langmuir-Hinshelwood kinetic model. This supports the working hypothesis of this research that reductive dechlorination of chlorinated ethanes occurs on the surface of active solids formed in mixtures of Fe(II) and cement. Transformation products for 1,1,1-TCA and 1,1,2,2-TetCA in mixtures of Fe(II) and cement were identified. The major product of the degradation of 1,1,1-TCA was 1,1-DCA, which indicates that the reaction followed a hydrogenolysis pathway. However, a small amount of ethane was also observed. TCE* was rapidly produced by degradation of 1,1,2,2-TetCA and is expected to undergo ò-elimination to produce acetylene. Dechlorination of 1,1,1-TCA in suspension of Fe(II), cement and three soil minerals (biotite, vermiculite, montmorillonite) was characterized using batch reactors. A first-order rate model was generally used to describe the dechlorination kinetics of 1,1,1-TCA in this heterogeneous system. The rate constants for 1,1,1-TCA in mixtures of Fe(II), cement and soil minerals were influenced by soil mineral types, Fe(II) dose and the mass ratio of cement to soil mineral. It was demonstrated that structural Fe(II) and surface-bound Fe(II) in the soil minerals affect dechlorination kinetics and the effects vary with mineral types. Furthermore, it suggests that the reductant formed from Fe(II) and cement hydration components is also effective in systems that include soil minerals