bluuebunny/crossref_metadata_2025 huggingface dataset:
The policy of free healthcare for children under the age of 6 years in Vietnam: assessment of the uptake for children hospitalised with acute diarrhoea in Ho Chi Minh City
Authors: Shieh Mae , Thompson Corinne , Phan Vu Tra My , Thi Thuy Linh Van , Tediosi Fabrizio , Merson Laura , Farrar Jeremy J. , Manh Tuan Ha , Lu Viet Ho , Thi Ngoc Tuyet Pham , Baker Stephen
Published: October 2013

Objective

To assess the proportion of, and reasons for, households not utilising the policy of free healthcare for children under 6 years of age (FCCU6) for hospitalisation with diarrhoea, and assess the risk of catastrophic expenditure for households that forgo FCCU6 and pay out of pocket.

Methods

Invoices detailing insurance information and charges incurred from 472 hospitalised diarrhoeal cases in one paediatric hospital in Ho Chi Minh City were retrieved. Hospital charges and the utilisation of elective services were analysed for patients utilising and not utilising FCCU6. Associations between socio‐economic factors with non‐utilisation of FCCU6 were evaluated.

Results

Overall, 29% of patients were FCCU6 non‐users. The FCCU6 non‐users paid a median hospital charge of $29.13 (interquartile range, IQR: $18.57–46.24), consuming no more than 1.4% of a medium‐income household's annual income. Seventy per cent of low‐income FCCU6 non‐users utilised less‐expensive elective services, whereas only 43% of medium income patients and 21% of high‐income patients did (P = 0.036). Patients from larger households and those with a parent working in government were more likely to use FCCU6.

Conclusions

The rate of FCCU6 non‐usage in this study population was 29%. A significant proportion of those that did not use FCCU6 was from lower income households and may perceive a justifiable cost–benefit ratio when forgoing FCCU6. Although a single diarrhoeal hospitalisation is unlikely to induce a catastrophic expenditure, FCCU6 non‐usage may disproportionately increase the risk of catastrophic expenditure for lower income households over multiple illnesses.
Disruption of Clathrin‐Mediated Trafficking Causes Centrosome Overduplication and Senescence
Authors: Olszewski Maciej B. , Chandris Panagiotis , Park Bum‐Chan , Eisenberg Evan , Greene Lois E.
Published: October 2013

The Hsc70 cochaperone, G cyclin‐associated kinase (GAK), has been shown to be essential for the chaperoning of clathrin by Hsc70 in the cell. In this study, we used conditional GAK knockout mouse embryonic fibroblasts (MEFs) to determine the effect of completely inhibiting clathrin‐dependent trafficking on the cell cycle. After GAK was knocked out, the cells developed the unusual phenotype of having multiple centrosomes, but at the same time failed to divide and ultimately became senescent. To explain this phenotype, we examined the signaling profile and found that mitogenic stimulation of the GAK KO cells and the control cells were similar except for increased phosphorylation of Akt. In addition, the disruption of intracellular trafficking caused by knocking out GAK destabilized the lysosomal membranes, resulting in DNA damage due to iron leakage. Knocking down clathrin heavy chain or inhibiting dynamin largely reproduced the GAK KO phenotype, but inhibiting only clathrin‐mediated endocytosis by knocking down adaptor protein (AP2) caused growth arrest and centrosome overduplication, but no DNA damage or senescence. We conclude that disruption of clathrin‐dependent trafficking induces senescence accompanied by centrosome overduplication because of a combination of DNA damage and changes in mitogenic signaling that uncouples centrosomal duplication from DNA replication.
Use of biometric, hematologic, and plasma biochemical variables, and histopathology to assess the chronic effects of the herbicide prometryn on Common Carp
Authors: Velisek J. , Stara A. , Zuskova E. , Svobodova Z.
Published: October 2013

Background

Effects of acute and subchronic exposure of fish to s‐triazine herbicides have been well documented, but data on the effects of prometryn on blood analytes in carp at environmentally realistic concentrations are lacking.

Objective

The objective of the study was to determine whether biometrics, blood analytes, and histopathology could serve as bioindicators in fish living in waters polluted by triazine.

Methods

Fish were exposed to prometryn at concentrations of 0.51 (reported concentration in Czech rivers), 8.0, and 80 μg/L for 14, 30, and 60 days. Prior to and during this period, biometrics, blood analytes, and histopathology were evaluated.

Results

After 60 days' exposure to 8.0 and 80 μg/L of prometryn, spleen weights (P < .05) and lactate (P < .01) levels were significantly lower, and concentrations of HGB (P < .01) and MHC (P < .01) and MCHC (P < .01) were higher, relative to controls. After 30 and 60 days' exposure to 0.51, 8.0, and 80 μg/L of prometryn, AST activity, calcium, magnesium, and inorganic phosphate levels were lower (P < .01), while creatinine concentration and ALT activity were higher (P < .01) than in controls. Glucose was higher after exposure to 80 μg/L after 30 and 60 days, and after 60 days' exposure to 8.0 μg/L. Renal histology revealed severe hyaline degeneration of the epithelial cells of caudal kidney tubules in fish at all exposure levels.

Conclusions

This study shows effects in fish blood at a concentration of 0.51 μg/L of prometryn, a significant finding in view of prometryn reaching a maximum of 4.4 μg/L or less in European rivers. Select blood analytes, such as creatinine, and histologic changes in caudal kidney are potential biomarkers for monitoring residual triazine pesticides in Common Carp.
Acoustic and cavitation field of an orthopedic shock wave device HMT Equitron
Authors: Chitnis Parag , Cleveland Robin
Published: October 2013

Extracorporeal shock wave therapy (ESWT) is a recent development in the treatment for orthopedic ailments. The SW devices are typically reduced versions of lithotripters. Measurements were taken on a HMT Equitron with a 35-mm focal length shock head. Acoustic measurements were taken with a PVDF membrane hydrophone. The average peak positive and peak negative pressures were observed to be 20 MPa and 12 MPa, respectively, with little dependence on the energy level. The focal spot was found to be 15 mm long and 16 mm wide. The cavitation field induced by SWs was measured using a passive cavitation detector (PCD) consisting of a 1-MHz focused transducer. Cavitation bubbles generated two acoustic emissions similar to the response observed in lithotripsy. The first emission coincided with the arrival of the shock waves and the second with the inertial collapse of the cavitation bubbles. The characteristic time (tc) was obtained by the time difference of the two signals. The region of strong cavitation field corresponded to the focal region of the acoustic field. The Gilmore equation was used to predict bubble response from the measured acoustic waveforms and the results were in agreement with PCD measurements. [Work supported by NIH.]
Analysis of deformation process of cells and internal bubbles by shock waves for developing DDS and bioprocess
Authors: Tamagawa Masaaki , Matsumoto Atsushi , Yamanoi Ichiroh
Published: October 2013

This paper describes the fundamental investigation for developing drug delivery systems (DDS) by shock waves and high efficient environmental bioprocess by shock wave, in which the microcapsules and cells have internal bubbles to crack the membrane easily. In this study, the analysis of flow using computational fluid dynamics (CFD) and optical visualizations for these two common phenomena were carried out. As for the analysis, the effects of the differences of acoustic impedance between internal fluid media and the outer cell and moving boundary of the cell on the pressure were examined. The result showed that the effects were large for the deformation process of the internal bubble and cell. Regarding the visualization, the deformation process of a bubble near the elastic wall as a model of cell membrane by shock waves was observed to analyze the behavior of the bubble in the cell for bioprocess or microcapsule for DDS. From these observations of deformation process, it was suggested that there should be optimized or critical point to have large deformation and displacement of the bubble by changing the initial position and diameter of the bubble in the cell and relative curvature of the elastic wall (cell diameter).
A comparison of techniques for simulating the signal received by a moving hydrophone at short range in shallow water
Authors: Duncan Alec J.
Published: October 2013

This paper presents two techniques for time series simulation applicable to the case of a moving hydrophone a few water depths from a broadband sound source. The first technique is based on the well-known image method but extends its applicability to low frequencies by accurately incorporating the physics of the seabed reflection process. The second technique is based on Fourier synthesis using transfer functions calculated using a standard fast-field propagation code. Transient and continuous-wave signals calculated using the two methods are shown to be in excellent agreement, even at frequencies where the water depth is less than half a wavelength. [Work supported by the Defence Science and Technology Organisation, Australia (DSTO).]
Complex resonance frequencies numerically obtained in the rectangular room with arbitrary wall impedances
Authors: Bistafa Sylvio R. , Morrissey John W.
Published: October 2013

Numerical methods to finding the complex resonance frequencies in the rectangular room with arbitrary wall impedances are presented. The eigenvalue equation is written in such a way that allows the unambiguous identification of each Riemann sheet. One numerical procedure applies the Newton method. For each wall-pair mode, the complex resonance frequencies are found, in each Riemann sheet, by small perturbations to the impedances of the wall pair. Another procedure transforms the eigenvalue equation into two differential equations, which are numerically integrated by the homotopic continuation procedure. The latter procedure is faster and finds all possible solutions. From the knowledge of sound decays experimentally obtained in a hard walled rectangular room, the impedances of the hard walls are obtained, which are then used to predict sound decays in the same room with one surface lined with sound absorbing material. It is shown that groups of modes with different reverberation times may collectively produce sound decays not always consistent with the Sabine prediction, and with some experimental results in a rectangular room with the floor covered with sound absorbing material of known acoustic impedance.
Scattering-induced attenuation of a fast longitudinal wave propagating in a trabecular bone modeled as a nondissipative porous medium
Authors: Luppe Francine , Conoir Jean-Marc , Franklin Herve
Published: October 2013

In this work, the calcaneus is modeled as a porous medium, made up with cortical bone and marrow. The Biot theory is used to describe acoustic propagation, in the 0.2–1 MHz range. In this frequency domain, the marrow viscosity effect is negligible, so that the calcaneus is considered as a nondissipative porous medium. In that same frequency range, however, the largest pores can not be included in the Biot modelization, as they may be larger than the acoustic wavelengths. They are hence supposed to act as scatterers, which radiate energy in other directions than an incident fast longitudinal plane wave. By use of an independent scattering approximation, with a unit scattering cell composed of two marrow filled cylinders, the effective attenuation induced by multiple scattering is studied, for different values of bone porosity and spatial arrangement of the two cylindrical pores considered as one single scatterer.
Estimation of the Doppler shift frequency using selected phase information for high-frame rate blood flow imaging
Authors: Tanaka Naohiko , Ohtsuki Shigeo
Published: October 2013

A new signal processing approach is presented for the estimation of the Doppler shift frequency in high-frame rate blood flow imaging with fewer pulse transmission. When an ultrasound pulse is transmitted to a large number of scatterers, the echoes from the scatterers overlap and interfere with one another. This interference causes a fluctuation in the phase of the received echo signal, and the estimation of the Doppler shift frequency will be disturbed by this phase fluctuation. A new technique proposed here makes it possible to eliminate the disturbed phase information by the interference, and the remaining information is applied to the estimation of the Doppler shift frequency. The instantaneous frequency of the echo signal can be used as an index of the influence of interference. To test this technique, radio-frequency echo signal from the carotid artery is used for the simulation, and the error of the estimated Doppler shift frequency is evaluated for several cases. The result shows that better performance can be achieved using this technique in the case of a limited number of pulse transmissions.
Teaching musical technology at the University of Edinburgh
Authors: Campbell D. Murray
Published: October 2013

The teaching of musical technology at the University of Edinburgh dates from the appointment of John Donaldson as Professor of Music in 1845. One of the courses which he offered was on ‘‘The Structure, Compass and Properties of Musical Instruments,’’ the stated objective being ‘‘to discover the true principles on which musical instruments ought to be constructed, and which may lead, and have led, to the invention of new ones.’’ To this end he created a music classroom well equipped with acoustical apparatus and demonstration instruments. Out of Donaldson’s pioneering work developed a long-standing cooperation between the Faculty of Music and the Department of Natural Philosophy (later Physics and Astronomy) at Edinburgh. Currently two Honors Degree programs with a strong emphasis on musical technology are offered. One is a Bachelor of Music Degree in Music Technology; the other is a Bachelor of Science Degree in Physics with Music. Both programs include courses in introductory musical acoustics, acoustics of musical instruments, analysis and synthesis of sound, and practical music technology. The B.Sc. requires an advanced school qualification in physics and mathematics, but no music; the B.Mus. requires an advanced school music qualification, but less advanced scientific background.
Soundtrack: Focus on electronics
Authors: Rhea Thomas L.
Published: October 2013

A retrospective-perspective on the nexus where music composition, electronic technology, and music technology converge to facilitate production of underscoring, foley, and sound effects for motion pictures. Clips excerpted from the speaker’s film collection will be presented to illustrate: (1) the arrival of film sound, with a Vitaphone demonstration; (2) music editing, with illustrations of click track, and punches and streamers synchronization techniques; (3) production and layering of modern sound FX and foley; (4) musical examples of ‘‘Mickey Mousing,’’ and source music vs underscore distinctions; (5) demonstrations and film clips featuring electronic musical instruments used in the film score, e.g., theremin and Hammond Novachord; and (6) assembly of modern soundtrack elements to present a sonic ‘‘hyper-reality.’’ The thesis that early sound film workers anticipated many of the magnetic audio tape techniques developed by pioneers in the early production of electronic music will also be explored. [Support in the form of stipend, travel, housing, and technical personnel support provided during a Residency in 2000–2001 at the Institute of Electronic Arts (IEA) at Alfred University, NY. Film clips presented on DVDs mastered by Ms. Lara Odell.]
Acoustic resonators for measuring the thermodynamic and transport properties of industrial gases and for calibrating thermometers
Authors: Moldover Michael R.
Published: October 2013

At the NIST, high Q cylindrical acoustic resonators are routinely used to measure the speed of sound in difficult-to-handle process gases with uncertainties of 0.01% or less. Model intermolecular potentials are fitted to the acoustic data to obtain the gas density and heat capacities with uncertainties of 0.1% as well as estimates of the viscosity and thermal conductivity. We have developed novel, low-Q, acoustic resonators to directly measure the viscosity and thermal conductivity. Spherical resonators are used to measure the speed of sound in gases with sub-part-per-million uncertainties. An argon-filled spherical resonator was used to redetermine the universal gas constant R with a fractional standard uncertainty of 1.7×10−6. The same resonator was used to measure imperfections of the internationally accepted temperature scale (ITS90) in the range 217–303 K with uncertainties of 0.6 mK; this work is now being extended to 800 K. In effect, very accurate speed-of-sound measurements will be used to calibrate other thermometers.
The electro-mechanical impedance method for damage identification in circular plates
Authors: Zagrai Andrei N. , Giurgiutiu Victor
Published: October 2013

Among structural acoustics methods, the electromechanical (E/M) impedance method is a new method that is easy to implement on complex structures with minimum instrumentation and straightforward results. This new acoustic method benefits from the advent of commercially available low-cost piezoceramics that have opened new opportunities for structural identification. The structural dynamics is identified by obtaining the E/M impedance or admittance signatures of piezoelectric active sensors that are permanently attached to the structure. In the presented study, the E/M impedance method was used to identify the structural dynamics and the presence of damage in circular plates. An analytical expression, which accounts for both axial and flexural vibrations of a plate, was derived and validated through a set of experiments. The experimental results show good matching with the theory. Additional acoustic experiments were conducted to assess the presence of damage in circular plates for a particular set of boundary conditions. Some damage metrics were suggested to analyze the frequency spectrum obtained. The results show the changes in the E/M impedance spectrum due to damage presence. Future research will focus on the application of the E/M impedance to the acoustical diagnostics of aging aircraft structures.
Imaging and time reversal in random media
Authors: Papanicolaou George C.
Published: October 2013

Time reversal in random media can result in refocusing on the source with a resolution that is better than the diffraction limit. This is because of the multipathing that occurs in the random medium, making the time reversal array appear to be wider than it is. What is not clear, however, is why this phenomenon is statistically stable. That is, why the refocused spot size does not fluctuate in the random medium. The reason for this statistical stability is that it is a time domain phenomenon and does not occur with narrow band signals. I will explain this effect analytically and will also show how it can be used for imaging in random media.
Listening in the dark: Behavioral and neural mechanisms of acoustic recognition in a singing fish
Authors: Bass Andrew H.
Published: October 2013

Vocalizing species of teleost fish have a simple repertoire of species-typical signals central to their social and reproductive behavior. Male midshipman fish (‘‘the California singing fish’’) acoustically court females using ‘‘hums’’ that are long duration (secs 1h) and spectrally simple. Individual hums exhibit an essentially flat envelope consisting of a low fundamental frequency (90–100 Hz) and several harmonics. By contrast, naturally occurring acoustic beats show envelope modulations: the hums of neighboring males overlap to produce a beat with a difference frequency (0–8 Hz) in which amplitude and phase modulations result from the continual shifting of the two fundamental frequencies. Behavioral playback (phonotaxis) studies show that individual midshipman can use multiple signal parameters including hum duration, gap duration between successive hums, fundamental frequency, and intensity to distinguish hums from each other, while the effectiveness of beats as playback signals depends upon both beat modulation rates and depth of modulation. Neurophysiological evidence shows that auditory neurons in the midshipmans VIIIth nerve and midbrain encode the physical attributes of these signals mainly using spike rate and spike synchronization, mechanisms that we propose contribute to the neural templates adapted for both hum and beat recognition. [Research supported by NIH.]
On the increase of disintegration efficiency of an acoustic lithotripter
Authors: Singh V. R.
Published: October 2013

Currently, disintegration of renal calculi, noninvasively, with the use of lithotripters, is in common use. In the hospitals, commercial lithotripters like extra-corporeal shock wave lithotripters (ESWL) are in routine use. These systems are very cumbersome and expensive. Treatment of the patients also takes comparatively more time, due to more number of sittings. The high ultrasonic intensity used in such systems has side effects, and causes damage to delicate nerves and fibers in the surroundings of the stones present in the kidney. Therefore, the present lithotripters are required to be improved by increasing the efficiency of disintegration and other factors. In the present work, the increase in the disintegration efficiency of the ultrasonic lithotripters, in this case Siemens ESWL, is made by stimulating externally the main shock wave with an acoustic stress wave. The cavitation bubbles are found to implode faster, with more disintegration efficiency of the lithotripter, giving in turn, better treatment to the patient, with less sitting time and less ultrasound dosage level.
How important are torsion modes in bowed-string dynamics?
Authors: Inácio Octávio , Antunes José , Henrique Luis
Published: October 2013

In spite of the venerable history of bowed-string research, several aspects are still inadequately clarified. The importance of torsion modes on the motion regimes of bowed strings is one such issue. Experiments involving torsion are difficult to perform and most of the results available pertain to numerical simulations. The authors’ approach differs from previous efforts in two main aspects: (1) the development of a computational method quite distinct from the classic wave-propagation approach pioneered by McIntyre, Schumacher, and Woodhouse and (2) an extensive and systematic analysis of the coupling between torsion and transverse motions. The numerical simulations are based on a modal representation and a friction model that enable accurate representations of the stick-slip friction forces and of the string dynamics, in both time and space. Many relevant aspects of the bowed-string can be readily implemented, including string inharmonic behavior, finite bow-width and torsion effects. Concerning the later aspect, a realistic range of the wave-speed ratio α≡CTors/CTran=2∼7 is investigated, for several values of the bow velocity and normal force. The results suggest that torsion modes can affect both transient durations and steady state regimes, in particular when α<4. Gut strings should then be particularly prone to torsion effects.
The new standard’s HVAC background noise requirements and their implementation in building design
Authors: Schaffer Mark E. , Lilly Jerry G.
Published: October 2013

The new ANSI classroom standard recommends long-term, steady-state background sound level limits of 35 dBA and 55 dBC. Since the HVAC system is typically a room’s dominant steady-state noise source, it is usually reasonable to apply these limits to the design of the system, assuming that other noise sources produce insignificant additions to the room’s long-term background noise environment. The recommended sound level limits are significantly lower than current industry standards, and complying with them will increase system costs. School administrators, architects, and HVAC system designers should, therefore, be prepared for the changes. This paper summarizes equipment selection and system design guidelines that have been found to be necessary for ensuring compliance with the sound level limits.
Measurements of acoustic Einstein–Hopf drag on objects undergoing volume oscillations
Authors: Tucholski Edward , Larraza Andres
Published: October 2013

It has been shown theoretically that the drag on an object undergoing volume oscillations can be modified by the presence of isotropic, homogeneous, broadband acoustic noise, when the band overlaps the objects resonance width [Larraza and Tucholski, Phys. Rev. Lett. 84, 2378–2380 (2000)]. These results constitute an acoustic analog to the Einstein–Hopf drag on an oscillating dipole in the presence of electromagnetic fluctuations. However, an important difference is that band-limited acoustic noise can reduce the drag when the lower frequency of the spectrum coincides with the resonant frequency of the object. Experimental results of the drag measured on bubbles and aerogel spheres moving in an band-limited noise field are reported.
Liquid droplet generation utilizing high intensity acoustic standing waves within shaped resonators
Authors: Roby Josh , Cameron Tim , Lipkens Bart
Published: October 2013

Generating liquid droplets from a bulk liquid underlies a vast number of process related technologies ranging from fuel combustion to respiratory drug delivery. Resonant Macrosonic Synthesis (RMS) is a technology that makes possible the generation of very high-amplitude shock-free acoustic standing waves within shaped resonators. Sound pressure levels in excess of 190 dB have been measured within RMS resonators. Bulk liquids subject to these high intensity oscillating acoustic waves are drawn into the acoustic field and atomized. Under continuous processing conditions water droplets on the order of 30 μm Sauter Mean Diameter have been generated with RMS. Droplet size measurements were obtained using a laser diffraction particle-sizing instrument. Data indicate that under all but the lowest liquid flow rates, liquid accumulates within the acoustic resonator, altering the processing characteristics. As liquid accumulation increases under fixed drive amplitude the power delivery, acoustic pressure, and acoustic resonance frequency drop, which coincides with increased mean particle diameters. Therefore the mean droplet diameters increase with an increasing liquid flow rate. Experiments have shown, however, that these characteristics are highly dependent on the process entry and removal points on the resonator.
Analytical/experimental studies of integral passive damping in composite isogrid structures
Authors: Gibson Ronald , Chen Yu
Published: October 2013

Composite isogrid structures are currently in use in a number of aerospace applications where the control of structural vibration response is an important design consideration. In this presentation, a recent investigation of the modal vibration characteristics of composite isogrid structures with embedded viscoelastic damping layers will be summarized. Analysis was done by means of a finite element method implementation of the modal strain energy method, while experiments were done by using an impulse-frequency response technique. Composite isogrid test panels were fabricated by a fast and inexpensive thermoplastic stamping process using two different co-mingled materials: glass/polypropylene and carbon/nylon. The damping materials were embedded at the interface between the ribs and the skin where the shear deformations are greatest in order to significantly improve the damping properties of the structures. It is found that the required amount of damping material can be reduced significantly if it is optimally placed. The modal vibration characteristics of composite isogrid structures are also compared with those of other composite structures such as laminates and sandwich panels. The authors gratefully acknowledge the support of the WSU Institute for Manufacturing Research, as well as donations of materials by Vetrotex America, Cytec Fiberite, and 3M Company.
A cross-linguistic study of articulatory timing in liquids
Authors: Gick Bryan , Campbell Fiona , Oh Sunyoung
Published: October 2013

A number of recent studies have observed that the timing of articulatory gestures is systematically different in prevocalic versus postvocalic allophones of English liquids. In English, the more anterior (consonant-like) gestures tend to occur at the peripheries of syllables, while more posterior (vowel-like) gestures occur nearer the syllable peak. These facts have allowed for a greatly simplified account of phonological processes involving English liquids, such as ‘‘vocalization’’ of postvocalic liquids, r- or l-coloring of vowels, and ‘‘dark’’ and ‘‘light’’ allophones of /l/. However, no such studies have been made of timing in liquids of other languages. In this study, ultrasound data were collected from one to three subjects for each of English /l/ and /r/, Quebecois French /l/, Mandarin /r/, and Korean /l/. Differences in intergestural timing were measured for prevocalic versus postvocalic allophones. Results show similar timing effects to those previously observed for English, with posterior gestures occurring earlier in postvocalic allophones. This property is consistent with phonological processes, such as pre-liquid laxing, observable in these languages. Quebecois /l/ and Mandarin /r/ were also interesting in exhibiting no measurable dorsal gesture at all in their initial allophones. [Research supported by the NSERC.]
MRI motion imaging of articulatory movement-coarticulation effects in velar consonants
Authors: Suzuki Noriko , Kitamura Tatsuya , Masaki Shinobu , Michi Ken-ichi
Published: October 2013

Magnetic resonance imaging (MRI) techniques have been used in speech research for measuring the vocal tract. Recently, MRI motion imaging has been developed and applied to the study of speech production. In this study, the coarticulatory effects of Japanese velar stop consonants were measured using a synchronized sampling method. The MRI technique employed is a synchronized sampling technique which is a modification of one originally developed for cardiac motion imaging. Speech samples consisted of /aka/ and /aki/, including the Japanese velar stop consonant /k/ and vowel /i/, in normal subjects. Results depicted motion of the speech organs in the midsagittal plane. When velar consonants were followed by a back vowel /a/, the back of the tongue contacted the posterior part of the soft palate, and when followed by front vowel /i/, tongue contact was more toward the anterior of the soft palate. Thus the tongue contact position for Japanese velar stop consonants was found to be strongly influenced by the following vowel.
Inversion for source and environmental parameters using a broadband rotated coordinates technique
Authors: Neilsen Tracianne B. , Knobles David P.
Published: October 2013

The problem of localizing and tracking a source in the shallow ocean is often complicated by uncertainty in the environmental parameters. Rotated coordinates [M. D. Collins and L. Fishman, J. Acoust. Soc. Am. 98, 1637–1644 (1995)] calculated for a broadband cost function are used in simulated annealing to invert for both source and environmental parameters. The resulting broadband rotated coordinates identify the coupling and relative sensitivity the parameters over the specified bounds. Multiple sets of broadband rotated coordinates, each corresponding to a different set of bounds, are used to systematically decouple the parameters. The cost function minimized in the inversion algorithm is model-data cross-phone spectra summed coherently over phone pairs, frequency, and time sequence. The results of applying this inversion method to simulated array data are presented along with preliminary results using data from the Area Characterization Test II experiment performed on the New Jersey continental shelf. [Work supported by ONR.]
Matched-field inversion of seabed geoacoustic properties complemented by chirp sonar surveys
Authors: Turgut Altan , Wolf Stephen
Published: October 2013

Matched-field inversion of range-dependent seabed parameters is studied using broadband (525–725 Hz) acoustic data collected on the New Jersey Shelf during the SWARM95 experiment. An efficient global optimization scheme is used to minimize an objective function defined by the Bartlett processor output in both beam and mode space. With the input from chirp sonar bathymetry and sediment thickness data, a broadband acoustic field is calculated by a coupled normal mode model and range-dependent geoacoustic properties are inverted. An independent chirp sonar inversion of acoustic impedance profiles was also performed along the same track by using chirp sonar data. The inversion results indicate good agreement between two inversion methods and show their effectiveness if they are used as complementary to each other. The effect of a strongly range-dependent water column on the inversion performance and possible broadband inversion using single hydrophone is also studied. [Work supported by ONR.]
Using an adjoint model to invert for unknown perturbations to a presumed environment
Authors: Hursky Paul , Porter Michael B. , Cornuelle Bruce , Hodgkiss William S. , Kuperman William A.
Published: October 2013

Adjoint modeling is an inversion technique that has the potential to sharply reduce the number of modeling runs typically needed to achieve an inversion. Although adjoint models are being used in oceanographic and meteorological modeling, they seem to have been overlooked by the acoustics community. A single adjoint modeling iteration calculates an adjustment to forward model control inputs (initial conditions and boundary conditions) needed to correct for a mismatch between predicted and measured system parameters. We will present how the adjoint of an acoustic propagation model can be used to trace a mismatch in predicted and measured acoustic parameters back to the perturbations in the environmental parameters needed to correct for the mismatch.
Seabed and sub-bottom classification using measurements of normal incidence backscatter from 1–10 kHz
Authors: Osler John C. , Hines Paul C. , MacDougald Darcy J.
Published: October 2013

It has been established that the first and second normal incidence acoustic returned from the seabed can be used as a classification tool to discriminate between different sediments. Typically this is accomplished using monostatic echosounder systems that operate in the range of several 10 s of kHz so that bottom roughness at the seabed interface is the dominant scattering mechanism. Model results (Hines and Heald, Proceedings of the Institute of Acoustics Conference on Acoustical Oceanography, Southampton, UK, April 2001) indicate that at lower frequencies, normal incidence returns from the sub-bottom should provide an additional discrimination tool without significantly corrupting the information contained in the interface scatter returns. This paper presents an experimental methodology for making these measurements in the 1 to 10 kHz frequency band using a vertical line array of receivers and a downward-looking superdirective projector array. Results from experiments at the ONR Strataform area and Scotian Shelf will be compared with independent geo-acoustic information.
Speech privacy design and masking sound systems
Authors: Roy Kenneth P.
Published: October 2013

The term ‘‘speech privacy’’ when applied to the office building segment must be considered both from the point of view of the person talking and from that of the listener. The achievement of adequate speech privacy for a particular situation is based on both the architectural design of the space, and the acoustical factors including speech and noise characteristic. The signal to noise ratio is the key to privacy performance, and this will be addressed by review of a case study for a recent office application. Electronic masking sound is a key concept in the attainment of speech privacy; and a new approach to masking system design will be reviewed, including an improved speaker concept, source DSP, and modeling tools.
System for measurement of microphone distortion and linearity at very high sound levels
Authors: Frederiksen Erling
Published: October 2013

Even if sound measurements are made over a very wide dynamic range, say from 0 dB to 180 dB, the applied instruments are typically tested only at one level, which is most often within the range between 94 dB and 124 dB. Is this enough? Some types of microphone have probably never been tested at medium and high levels, as neither standardized nor generally agreed methods are described or available. However, today aerospace organizations, accreditation bodies and laboratories performing pattern approval of instruments ask for documentation, methods, and test equipment. Therefore, B&K decided to develop a system for generation of sound pressure over a wide dynamic range for routine testing of measurement microphones and pressure transducers. This paper describes the design and the properties of the system, which generates high pressures by a system of coupled tubes with standing waves. The general operation principle is not new, but the system, which can operate upon an ordinary laboratory table, is refined and optimized for a generation of levels as high as 174 dB at 500 Hz with a very low distortion (attention is paid to third harmonic distortion, which indicates lack of linearity).
Measurement of background noise in piezoelectric and electret condenser microphones
Authors: Zuckerwar Allan J. , Serbyn M. Roman
Published: October 2013

An upgraded version of a previously described acoustic isolation vessel [K. C. T. Ngo and A. J. Zuckerwar, J. Acoust. Soc. Am. 93, 2974–2980 (1993)] has been used to investigate the background noise in piezoresistive and electret condenser microphones over the frequency range 1 Hz–100 kHz. The test microphones represent four different manufacturers. Theoretical models for predicting the noise characteristics of piezoresistive (nonreciprocal) and electret condenser (reciprocal) microphones are proposed. In particular, the results of 1/f noise measurements on these microphones are compared with those previously obtained from air condenser microphones.
The performance of two-dimensional acoustic resonators with large openings
Authors: Line K. Scott , Anderson Michael J. , Budwig Ralph S.
Published: October 2013

We address the design of acoustic resonators with large openings. This problem is of interest to those who wish to achieve high levels of acoustic amplification in spite of energy leakage through the openings. A 2-D analytical model was used to predict the performance of a rectangular resonator with rigid walls and compare the performance to the corresponding situation for a cavity between two rigid semi-infinite walls. The fluid in the resonator was air, and the dissipation model included body absorption and simplified boundary layer losses. It was found that the collimation of the transducer field, and the nature of the attenuation model determined the performance of a resonator with large openings. For the dissipation model used, it was predicted that optimal performance of a resonator with openings would be obtained at a transducer ka of approximately 100. Experimental measurements of closed and open cavity quality factors, for transducer ka ranges lower than 100, showed the same trends as analytical predictions, however, the measured quality factors were much lower than the analytical predictions.
Model studies of source term and reflection components of synchronous-evoked and distortion product otoacoustic emissions
Authors: Talmadge Carrick , Tubis Arnold
Published: October 2013

The unified model of synchronous-evoked, distortion product, and spontaneous otoacoustic emissions of Talmadge et al. [J. Acoust. Soc. Am. 104, 1517 (1998); 105, 275 (1999); 108, 2570 (2000)] provides a useful testing ground for various paradigms that have been proposed for separately determining source terms and reflectance components of synchronous-evoked and distortion-product otoacoustic emissions. The source terms are the ear canal components that would exist in the absence of effects associated with cochlear wave reflections due to, e.g., distributed inhomogeneities [Zweig and Shera, J. Acoust. Soc. Am. 98, 2018 (1995)] and nonlinearity [Talmadge et al., 2000]. Model calculations are used to compare results for the unmixing of these components obtained using reflection-suppression techniques [see, e.g., Kalluri and Shera, J. Acoust. Soc. Am. 109, 622 (2001)] and various forms of time-domain latency windowing ones [see, e.g., Knight and Kemp, J. Acoust. Soc. Am. 107, 457 (2000)]. Because of multiple internal wave reflections at the cochlear base and the tonotopic place for the cochlear waves, the model implies (and experimental data indicate) that the reflectance components will generally exhibit fine structure effects similar to those of the total ear canal signal.
Use of the two channels method to determine the guided waves damping coefficients of an asymmetrically fluid-loaded plate: Theory and experiment
Authors: Mounsif Ech-Cherif El-Kettani , Herve Franklin
Published: October 2013

Exact and approximate formalisms describing the interactions of acoustic plane waves with an elastic isotropic plate immersed between two different fluids are presented. This is an extention of the Fiorito, Madigosky, and Berall (FMU) theory. Resonant approximations are given for the reflection and transmission coefficients, which assume light fluids loading. These approximations show that the resonance widths are the sum of two independent partial widths, each of them being related to one fluid and to the plate physical properties. In addition, experimental results are presented for a steel plate; the damping coefficients of the propagating leaky Lamb waves along the loaded plate are measured in two different loading situations. In the first situation the plate is embedded in water (water loading on both sides), while in the second situation it is loaded with water on one side and acetone on the other side. The experimental damping coefficient of the acetone-steel-acetone structure is deduced therefrom. The damping coefficient obtained in each case is then compared to the theoretical half resonance width, and the experimental results are found to be in good agreement with the theoretical predictions.
Intonation patterns in productions by Seoul Korean speakers of English
Authors: Tevis McGory Julia
Published: October 2013

This study compares the intonation patterns produced in English declaratives and yes–no questions by native American English speakers and native Korean speakers. As is well known, stress and pitch accent are integral to English intonation. Declaratives are produced with an F0-rise (L+H*) in the stressed syllable of the most prominent word followed by a steep utterance-final fall while yes–no questions are produced with a sharp F0-fall (L*) onto the stressed syllable followed by a gradual utterance-final rise. Words that follow the focused word are not associated with any particular F0 pattern. In contrast, Korean has neither stress nor pitch accent. Prominent words in statements and questions are produced at the beginning of a phrase and realized with an F0-rise (LH) followed by a gradual fall to the end of statements (L%) and a final rise (LH%) in questions. In this study, subjects from both subject groups produced the words ‘‘memorial’’ and ‘‘memorizes’’ in both focus and post-focus positions in both statements and yes–no questions. The question of interest is whether Korean speakers follow the intonational pattern of English (their L2) or utilize the intonational characteristics of their native language.
Articulatory gestures of /l/ by bilingual Korean–English children
Authors: Oh Sunyoung
Published: October 2013

Properties of articulatory gestures (e.g., timing and magnitude) have been used to find the phonetic correlates of syllable position. For example, allophones of English /l/ are determined by the timing relationship between the tongue tip and dorsum gestures, where greater timing lag is observed in the post-vocalic position. On the other hand, allophones of Korean /l/ are determined by the position of the tongue tip, prevocalic post-alveolar versus post-vocalic alveolar. The magnitude of both gestures is also greater in post-vocalic position, and the tongue dorsum is slightly advanced in Korean. This paper examines cross-language influences of the articulatory gestures of /l/. To test this, an ultrasound study of the speech of two bilingual Korean–English children was conducted. The results showed that bilingual children produced /l/ using the correct tongue tip gestures of Korean in both positions (post-alveolar versus alveolar); however, they failed to implement tongue dorsum advancement. Instead, they incorrectly adopted the English-like gesture and implemented tongue dorsum retraction in post-vocalic positions. These indicate that bilingual children are attuned to language-specific gestures of both languages and there is at least a one-way effect (English to Korean) on /l/ gestures.
Acoustic analysis of American listeners’ Mandarin tone productions before and after perceptual training
Authors: Wang Yue , Jongman Allard , Sereno Joan A.
Published: October 2013

Training American listeners to perceive Mandarin tones has been shown to be effective, with the trainees’ identification improving by 21% [Y. Wang, A. Jongman, and J. Sereno, J. Acoust. Soc. Am. 106, 3649–3658 (1999)]. The effect on production as a result of perceptual training was first assessed by native Mandarin listeners’ evaluation of the trainees’ tone productions, showing that post-training productions were 18% more accurately identified than pre-training productions [Y. Wang, M. Spence, A. Jongman, and J. Sereno, J. Acoust. Soc. Am. 105, 1095 (1999)]. A detailed acoustic analysis has now been performed to further examine the nature of the production improvement. Trainees’ productions include 80 Mandarin words recorded both before and after perceptual training. For comparison, these words were also produced by native Mandarin speakers. For each production, a pitch track was derived. Results show that post-training tone contours approximate native norms to a greater degree than pre-training tone contours, indicating an improvement in production following perceptual training. Furthermore, pitch height and pitch contour are not mastered in parallel, with the former being more resistant to improvement than the latter. The results are discussed in terms of the production–perception relationship and native language influence.
Perception of coarticulation with Japanese voiced and voiceless vowels
Authors: Hashimoto Tomomi
Published: October 2013

Two experiments investigate whether coarticulatory information of voiced and devoiced vowels in their preceding segments can be exploited by speakers of different dialects and/or by second language learners. In standard Tokyo Japanese, the high vowels [i, u] are devoiced between voiceless segments while vowel devoicing is not typical in Osaka dialect. This study examines how vowel’s voicing status affects listeners’ ability to exploit coarticulatory information in initial consonants. In both experiments, listeners consisted of native speakers of Tokyo and Osaka dialects and native speakers of English learning Japanese as a second language. In the first experiment, the post-alveolar fricative /(esh)/ followed by a vowel, either /i/ or /u/, was produced in real words by native speakers of Tokyo and Osaka dialects. The listeners were presented with a series of excised /(esh)/ to determine the original vowel identity. The second experiment replicated the first experiment testing with the velar stop /k/. The preliminary results suggest vowel devoicing may cause perceptual difficulties in the fricative-vowel context, but not in the stop-vowel context. The results also indicate a difference in cue weighting among 3 groups. Explanation for this finding will also be explored by way of acoustic measurements.