bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceptual measures of visual and auditory cues in film music
Authors: Lipscomb Scott D.
Published: July 2002

Both musical sound and visual images have the ability to communicate. Visual images often convey explicit (verbalizeable) content, while musical sound lies most often in the implicit, nonverbalizeable realm. Music perceived as organized by a listener follows a culture-dependent rule system, differing from that found in verbal communication. Numerous investigations have determined specific cognitive strategies utilized in musical listening. Likewise, there have been similar studies devoted to strategies utilized in the cognition of visual images. Recently, there has been a significant amount of interest in the perceptual interaction between the auditory and visual systems in multi-modal contexts. Both psychologists and musicians are beginning to investigate the manner in which a stimulus perceived in one sensory modality may affect the cognitive processing of a stimulus in a separate modality. Beginning in the 1950s, a series of psychophysical investigations revealed cross-modal influences using simple stimuli. A number of investigators are presently attempting to incorporate more complex stimuli to determine the interrelationship of auditory and visual cues processed simultaneously in ecologically valid experimental contexts. Drawing upon research carried out by the author, this paper will highlight methods utilized successfully in such investigations, summarizing results and proposing future directions.
Source deconvolution and system identification of flow-excited acoustic systems
Authors: Bezemek Jacklyn D. , Mongeau Luc
Published: July 2002

A method for the characterization of flow-excited acoustic systems in the frequency domain was investigated. The approach, based on dimensional analysis and the hypothesis that the system may be described using a linear source-filter model, allows the source spectral distribution and the magnitude of the frequency response function to be obtained directly from sound-pressure spectra measured over a range of flow velocities. The objective as to determine whether the method could be used to predict the noise emissions of a small axial-flow cooling fan in a given installation from source and response functions evaluated using different calibration facilities. The spectral decomposition algorithms were first validated using a theoretical model. The influence of discretization errors and random errors in the input spectra was evaluated. The noise emissions of two different fans were then measured for two different computer enclosures and a calibrated plenum, following standardized procedures. The results demonstrated that the use of the spectral decomposition method as a pre- dictive tool was accurate in this case, provided the fan inflow was reasonably uniform. In addition, the method was found to be very robust to random errors in the input data. Discretization errors, however, had a significant impact on accuracy.
A novel method for characterizing contact-mode shear wave transducers in immersion
Authors: Hsu David K. , Fischer Brent A. , Dayal Vinay
Published: July 2002

The dominating shear motion of a contact-mode shear wave transducer is often accompanied by a weak parasitic longitudinal mode due to its finite size and constrained boundary conditions. The amplitude and phase of this out-of-plane vibration may be exploited for determining the shear polarization direction and for detecting any asymmetry or distortion of the shear transducer’s vibration pattern. In practice, the contact-mode shear probe is immersed in water and energized by an rf pulser to serve as the transmitter. A C-scan is then made of the face of the shear transducer using a focused longitudinal wave transducer as the receiver. The resulting image shows the out-of-plane longitudinal vibration of the shear transducer. For commercial contact-mode shear probes, this pattern usually consists of two crescent-shaped regions of higher vibration amplitude but of opposite phase. A line bisecting the two crescents and passing through their centers defines the shear polarization direction. Finite-element modeling of the shear displacement of a circular disk with constrained boundary confirmed the experimentally observed behavior. This approach provides a simple method for characterizing commercial shear wave transducers. [Work supported by Center for NDE, Iowa State University.]
V-R model predictions of averaged radiation from a violin compared with spatial average of bridge force hammer-excited direct radiation
Authors: Bissinger George A. , Bailey Machele
Published: July 2002

Mechanical modal analysis data for a violin furnish two essential components for the vibration-radiation (V-R) model [G. Bissinger, J. Acoust. Soc. Am. 97, 3154–3164 (1995)] to reliably predict the averaged radiative properties of a bowed string instrument from its measured mechanical properties, viz., (1) how strongly a particular corpus mode is excited at the bridge and (2) normal mode frequency and shape data for boundary element acoustic radiation calculations of the radiation efficiency for each corpus normal mode. Combining both of these elements in the V-R model gives predictions of a spatially averaged acoustic radiation for a violin. These were compared with similarly spatially averaged measurements of direct radiation from a violin excited by force-hammer impact at the bridge using a rotating semicircular (r=30 cm) seven-microphone array in a small anechoic chamber covering almost an entire sphere around the violin. The V-R model calculations for each mode compared quite well in general to the measured average radiation.
A computer-aided paired-comparison algorithm using a 5-point comparison scale and its application to performing subjective ratings
Authors: Hsieh Hsiao-an
Published: July 2002

The paired-comparison method (PCM) is a common tool used for sound quality studies in the automobile industry. In using PCM, evaluators are asked to compare two noise samples and indicate their preference for every possible sample–pair combination. A preference ranking of all samples is then generated. This paper describes the development of a PCM based on a five-point comparison scale. The primary motivations for this work were: (1) the need of predicting preference ranking for an individual or small group of evaluators, and doing so with reasonable repeatability and accuracy; and (2) predicting an individual’s subjective acceptability ratings for all the samples without additional testing. Using a computer-optimization scheme on numerous simulated events, the author developed a weighting system for this comparison scale. A computer tool was subsequently written which incorporated this weighting system and measured the relative preference-distances among all noise samples based on an individual’s PCM inputs. The preference ranking was readily available, and the predicted subjective ratings were obtained by mapping these measured distances on a linear scale of 1 to N (1=totally unacceptable, N=perfectly acceptable). Some successes of using this method on real-life noise samples are presented and discussed. [See NOISE-CON Proceedings for full paper.]
Instability of an elastically supported Timoshenko beam under a traveling inertia load
Authors: Mackertich Seroj
Published: July 2002

The instability of an elastically supported infinite Timoshenko beam under constant velocity traveling inertia load has been investigated. The regions of dynamic instability are determined for different values of the elastic foundation constant. Since the occurrence of this dynamic instability reduces the axial buckling load of the beam, the result is important for the study of buckling of a continuous beam.
A computer-based certificate program in acoustics (noise control engineering)
Authors: Stuart Alan D.
Published: July 2002

The Pennsylvania State University, funded by a grant from the Alfred P. Sloan Foundation, is designing and developing a five-course Certificate Program in Acoustics. Scheduled to be offered in the Fall of 1997, this five-course program will allow geographically dispersed engineers working in, or seeking a career in, noise control engineering to participate in a variety of collaborative and individual learning activities that integrate basic engineering principles with real world examples and applications. Subject material is presented in multiple-media modules that blend CD-ROM-based instruction with text materials and computer conferencing. Each module is enhanced by a series of MatLab-based exercises and/or LabView-based experiments that provide instruction as well as serve as a resource that students can use in solving design problems. This computer-based certificate program makes appropriate use of technology to reach and serve students who are geographically distant from the faculty—and also from fellow students—and bring them together in new and interesting ways to create a unique kind of professional learning community. This paper will present an overview of this program. [See NOISE-CON Proceedings for full paper.]
Room noise criteria—A consultant’s experience
Authors: Lilly Jerry G.
Published: July 2002

There has been much controversy in recent years regarding the various room noise criteria that have been proposed and are in use today. Included in these criteria are the NC curves, the PNC curves, the RC curves, and most recently, the NCB curves. The NR curves, which are commonly used in Europe, must also be mentioned. The recent adoption of ANSI S12.2 has not resolved the controversy—in fact, it has actually heightened the debate because it acknowledges two room noise criteria (RC and NCB) that are clearly at odds with each other in the low-frequency region. This paper examines the limitations of each method (RC and NCB) and provides possible suggestions for modifications that might create a path for eventual resolution of this controversy. This paper also emphasizes the important characteristics of any room criteria method: it must be as simple as possible without sacrificing effectiveness, relatively easy to measure, and credible from the standpoint of human perception. In any event, it is the opinion of the author that any resolution will have to await the completion of the ASHRAE research project which is currently in progress in Australia. [See NOISE-CON Proceedings for full paper.]
Sesame I: Assessment of enhancement in the minimum detectable level using fluctuation-sensitive processors
Authors: Kooney S. F.
Published: July 2002

Minimum detectable level (MDL) measurements were made using a vertical array in a shallow-water environment during the Sesame-I experiment held in Aug.–Sept. 1995. A tapered source comb of four frequencies, 150, 154, 158, and 162 Hz, were broadcast at different levels and two depths at a range of 22 nmi. The MDL data were evaluated in terms of signal excess and standard deviation using the average-power processor and fluctuation-sensitive processors. It was found that the fluctuation-sensitive processors provided a signal enhancement of up to 7 dB in cases when the average-power processor’s signal excess was zero. In terms of standard deviation, the fluctuation sensitive processors could discern a signal buried deeper in the background noise (where the standard deviation of the noise levels were typically 5 to 6 dB) than could the average power processor. It was determined that fluctuation-sensitive processors could provide an enhancement of the MDL over the average-power processor. The methods of analysis will be discussed and the comparative performance of the algorithms will be presented. [Work supported by ONR and NRL].
A neural model predicting context effects in the identification of stops and glides
Authors: Myers Christopher W. , Cohen Michael A. , Grossberg Stephen
Published: July 2002

One class of phonetic context effects involves durational contrasts: A signal can be perceived as a stop consonant or a glide, depending on the length of the adjacent segment. For example, the syllable [wa] is perceived as [ba] if the steady-state frequencies corresponding to the vowel are lengthened. Thus the vocalic information affects reported phonetic judgments of the prior consonantal segment. The neural model presented processes consonant–vowel transitions and steady-state vowel signals by transient and sustained channels. This model predicts the experimental effects of vowel duration, CV transition rate, and frequency extent in identifying [ba] and [wa]. The product of a leaky integrator’s output with the quotient of two linear expressions in the stimulus parameters generates the model’s output. With a single small set of parameters, the model predicts over 99% of the variance in two data sets [J. L. Miller and A. M. Liberman, Percept. Psychophys. 25(6), 457–465 (1979); Schwab et al., Percept. Psychophys. 29(2), 121–128 (1981)]. It outperforms a number of simple alternative models. Implications for other phonetic distinctions and physiological analogs to the model in monkey cortex are described. [Work supported by AFOSR and ONR.]
Acoustic microscopy for characterization of high-temperature superconducting tape
Authors: Miyasaka Chiaki , Cobucci Chris , Tittmann Bernhard
Published: July 2002

Although material scientists constantly discover superconducting compounds with higher critical temperatures (Tc’s), manufacturing of the high-temperature superconductors (HTS) remains a problem and long lengths (>1 mile) have yet to be produced. In an effort to produce long length superconductors, manufacturing steps for HTS tape production have been critically looked at to find their effects in producing tape with the desired characteristics. In support of determining superconducting tape characteristics, acoustic microscopy offers the potential for internal microstructural material characterization. This research will ultimately support in-process monitoring of HTS manufacturing as part of an advanced sensing system to determine the presence of defects and/or the effects of process variables on the HTS tape. This presentation will overview scanning acoustic microscopy and present images of HTS tape at several frequencies ranging from 50 to 500 MHz. The results clearly demonstrate the feasibility of determining the Ag/ceramic interface location and the general integrity of the constituents.
Loudness summation at low levels and the form of the loudness function near threshold
Authors: Buus So/ren , Florentine Mary , Müsch Hannes
Published: July 2002

This study uses measurements of loudness summation to examine the form of the loudness function for tones near threshold. An adaptive, two-interval, two-alternative, forced-choice, roving-level procedure was used to obtain loudness-balance measurements between a 1600-Hz tone and tone complexes centered at 1600 Hz. The complexes consisted of equal-SL components with levels between about −3 and 20 dB SL. Frequency separations were one, two, four, or six critical bands for four-tone complexes and one or two critical bands for ten-tone complexes. Results for six young listeners with normal hearing show that the SL difference between the pure tone and the components of the equally loud tone complex near threshold averages about 4 dB for the four-tone complexes and about 7 dB for the ten-tone complexes. When the component level of the four-tone complexes with wide frequency separations is around 20 dB SL, the equally loud pure tone is near 47 dB SL. These results indicate that loudness may grow approximately as I1.5 (where I is tone intensity) near threshold and as I0.2 at moderate levels. [Work supported by NIH-NIDCD R01DC02241.]
Active classification of submerged structures by means of wave packet decomposition
Authors: Yen Nai-chyuan , Dragonette Louis R.
Published: July 2002

This paper addresses the exploitation of the information contained in a signal by means of wave packet decomposition. This general technique has a wide range of signal processing applications: The application considered here is sonar systems with a particular emphasis on providing a broader view of time-frequency waveform analysis for target classification. The acoustic response of a submerged object depends on its physical shape and structure and on its elastic properties. A methodology of nonorthogonal decomposition is used to reduce the scattered echoes into wave packets associated with the important scattering mechanisms. This decomposition method is based on the energy distribution of the individual components and can be related to the structural scattering physics. In the case of a sonar target, mechanisms such as specular reflections, creeping waves, Bragg waves, and Bloch waves from the different parts of target or scattering centers can be incorporated into the target characterization. By applying pattern recognition logic, the present study can serve as a useful background for new sonar system development with advanced processing techniques and state-of-the-art computer hardware. Examples from numerical simulations and laboratory measurements are used to discuss the effectiveness of this target classification scheme. [Work supported in part by ONR.]
Dynamics of single bubbles in laboratory sediments
Authors: Gaitan D. Felipe , Sabatier James M.
Published: July 2002

Increased interest in the acoustical properties of sediments has been motivated by the fact that in shallow-water environments the seabed is the dominant factor controlling propagation. With this in mind, the dynamics of a gas bubble surrounded by a poro-elastic medium in a laboratory sediment have been studied. Measurements of the effect of the surrounding medium on the resonance frequency and the quality factor of the bubble will be presented. [Work supported by ONR.]
An alternative feedback structure for the adaptive active control of time-varying periodic or time-varying narrow-band disturbance
Authors: Bouchard Martin , Paillard Bruno
Published: July 2002

For the feedback active control of noise and vibrations, there are still a few situations where today’s adaptive control algorithms do not perform well (slow convergence and/or bad transient response). In this paper, a feedback structure suited for the control of time-varying periodic or time-varying narrow-band disturbances is inspired from a technique used in today’s low bit-rate speech coders. The main concept is to separate the information and the processing pertaining to the plant from the information and the processing pertaining to the excitation signal (disturbance). Since the time constants of the variations of the plant are usually much longer than the time constants of the disturbance fluctuations, the adaptation effort can then be put on the prediction of the disturbance. Simulations will be presented, showing that either for low damping systems or multiharmonic disturbance signals, the algorithm presented in this paper can be compared favorably to a popular internal model control (IMC) structure that uses a stochastic gradient algorithm. [Work supported by I.R.S.S.T.]
Effects of masker envelope distribution on binaural masking at high frequencies: Evidence for the influence of peripheral compression?
Authors: van de Par Steven , Kohlrausch Armin
Published: July 2002

NoSπ thresholds were measured using a 3IFC paradigm for masker levels between 10 and 80 dB SPL. Three types of narrow-band maskers were used to investigate the influence of the envelope probability distribution on signal detectability. The three types were multiplied noise (MN), Gaussian noise (GN), and low-noise noise (LNN) each with a bandwidth of 25 Hz. Due to the rather low NoSo thresholds for LNN, both monaural and binaural detection cues might be used by subjects in the NoSπ condition. In order to avoid this, for LNN maskers, an NoSo stimulus was presented in the reference intervals at the same signal-to-noise ratio as in the NoSπ test interval. The results show that at medium levels (40–70 dB), thresholds in MN are about 10 dB lower than for the other maskers. This difference decreases or even disappears at low and high levels. It is proposed that these effects are related to the compressive transformations which occur in the cochlea. These transformations decrease the size of the interaural intensity differences present in the envelopes of the maskers, and can be shown to do so more effectively for GN and LNN maskers than for MN maskers.
On-line contactless measurement of the elastic modulus of a moving sheet by ultrasonic method
Authors: Khoury Mazen , Schroder Andre , Tourtollet Guy E.
Published: July 2002

There is still a strong interest in the paper industry for a contactless method that would allow the measurement of the elastic modulus of paper and of the anisotropy of this modulus in the sheet plane. A contactless method is presented that enables the measurement of the transmission coefficient of sound through a paper sheet, in the frequency range 200– 800 kHz, for incidence angles between −66 and +66. These measurements can be performed on a moving sheet at velocities in the same range as those observed on a paper machine. From the state equation of plate waves, the possibility to calculate the elastic modulus of paper was demonstrated by using only the equation of the first antisymmetric mode, without neglecting any term of it, contrary to what is commonly used in the literature. This model fits very well with measurements made and leads to consideration of the development of an on-line version for use on industrial paper machines.
The effect of surface noise in low-frequency passive detection in coastal waters
Authors: Sanders William M. , Tappert Frederick D.
Published: July 2002

The effect of the environment on sensor performance is twofold. Signal level and local noise level are both affected by acoustic propagation. In performance analyses, noise level is often taken to be a spatially homogeneous and temporally constant value. This paper utilizes a three-dimensional propagation model to determine the detection properties of bottom-mounted passive low-frequency sensors. The parabolic equation (PE) model is used to propagate noise from a field of surface dipole sources to the sensor location. Summation of noise from the entire area under consideration yields the local noise level. Two environments are considered. In the Adriatic Sea, the acoustic environment emphasizes local noise sources. In the Florida Straits, noise from distant sources affects local noise levels.
Scattering from a fluctuating object in a fluctuating waveguide
Authors: Makris Nicholas C.
Published: July 2002

In many practical applications of active target scattering in ocean acoustics, there is a significant amount of uncertainty in both the scattering properties of the target and the propagation characteristics of the medium. In order to consistently combine a reasonable description of this uncertainty with the established physics of scattering from submerged objects, a statistical model is developed that describes both the spatial and temporal characteristics of the scattered field. An essential aspect of this model is the multiplicative nature of the scattering process. The acoustic field propagates from the source through a random waveguide. It is then scattered from a random target that undergoes fluctuations that are uncorrelated with those of the incident field. This scattered field then propagates into azimuthal directions where the random waveguide to the receiver may be partially or fully uncorrelated with the incident waveguide. Standard assumptions for statistical fluctuations of the waveguide channels and target lead to a non-Gaussian field at the receiver. Possible randomness of the sound source leads to a further departure from Gaussianity in the received field statistics. Expressions for the spatio-temporal mutual intensity structure of the received field will be provided, with illustrative examples for a shallow water scenario.
Recent progress in the INRS speech recognition system
Authors: O’Shaughnessy Douglas D. , Lee Clark Z. , Savariaux Christophe , Farhat Azarshid , El Méliani Rachida , Vergin Rivarol , Héon Michel
Published: July 2002

The INRS large-vocabulary continuous-speech recognition system employs a two-pass search. First, inexpensive models prune the search space; then a powerful language model and detailed acoustic–phonetic models scrutinize the data. A new fast match with two-phone lookahead and pruning speeds up the search. In language modeling, excluding low-count statistics reduces memory (50% fewer bigrams and 92% fewer trigrams); with Wall Street Journal texts, excluding single-occurrence bigrams and trigrams with counts less than five yields little performance decrease. In acoustic modeling, separate male and female right-context VQ models and a bigram language model are used in the first pass, and right-context continuous models and a trigram language model are used in the second pass. A shared-distribution clustering uses a distortion measure based only on the weights of Gaussian mixtures in the HMM model. Testing the system with a 5000-word vocabulary, the word inclusion rate (i.e., correct word retained in the first pass) is about 99%; word recognition accuracy is about 92.5%. Keyword spotting with new types of fillers retains accuracy with 1.2 false alarms/hour/keyword. [Work supported by NSERC-Canada and FCAR-Quebec.]
Numerical investigation of strong-pulse propagation from shallow to deep water
Authors: Piacsek Andrew A.
Published: July 2002

Finite-difference calculations of strong pulses propagating downslope in typical littoral environments were performed using the NPE program [B. E. McDonald and W. A. Kuperman, J. Acoust. Soc. Am. 81, 1406–1417 (1987)], modified to include a seabed depth that varies with range and which provides for a specification of sound-speed gradients in the bottom as well as in the water column. In these simulations, the bottom is modeled with a (compressional wave) sound-speed profile that corresponds to mud and silt overlying a sandstone bedrock; an attenuation coefficient of 0.6 dB per wavelength is applied throughout the bottom. Results indicate that a significant fraction of the acoustic energy will generally reach deep water off the continental shelf, although this is strongly influenced by the water depth at the source and the distance of shallow-water propagation leading to the shelf. In addition, the strong refraction of the pulse in the upper seabed layers and the subsequent reradiation into the water column generates head waves that are generally preserved into the deep water. This feature may potentially serve as a discriminant between seismic and explosive sources and, in the latter case, to characterize the source environment. [Work supported, in part, by DOE through the Lawrence Livermore National Laboratory.]
Rate of energy transport and arrival times in pulse propagation in a waveguide
Authors: Sidorovskaia N. A. , Werby M. F.
Published: July 2002

The concept of group velocity has one of three origins and is described in terms of a mathematical construct to predict arrival times in pulse propagation in a waveguide, particularly within the context of normal mode theory. Under certain conditions, group velocity can lead to confusion. On the other hand, the rate of energy transport, which is what one really seeks, may be derived by taking the ratio of the mean energy flux through a vertical section with the energy density between two planes separated by a wavelength. In the context of normal mode theory, this leads to an integral expression that involves the normalized vertical wavefunctions and the velocity profile leading to a physically appealing expression that lends insight to expected modal arrivals. Under certain conditions, it leads to the same results as the group velocity concept: It can be calculated with only one frequency and is valid near cutoff frequencies. This supplies one with an integral expression for a velocity that better characterizes arrival times of packets of energy. [Work sponsored by ONR, the Naval Research Laboratory, and the University of New Orleans.]
Second-order solutions for arbitrary piston radiators
Authors: Westervelt Peter J.
Published: July 2002

Eckart’s equation in the presence of the volume source density q is ⧠2[π+2(Ψ2),00]=ΓV,00−ρ0c0q,0. The interaction terms [(ρ0−ρ)c0q,0−qc0ρ,0] are absent, a consequence of ⧠2ρs=−ρ0c0q,0. If the approximate first-order solution for a radiator with directivity D1(ω,θ,φ), p1=P0r0|r′|−1D1[cos(ωt−kr+Ψ)]exp[ −rα(ω)] in which r′=r0+ir, r0=Rayleigh distance, Ψ=arctan(rr0−1), P0=ρoc0u0 with piston velocity u0, is introduced into Eckart’s equation the second-order pressure is obtained: p2=Γ(4ρ0c20)−1P20D21kr20|r′&u|−1[(ln|r′|r0−1)2+Ψ2]1/2[cos( 2ωt−2kr+Ψ−χ)]exp[−2rα(ω)] in which χ=arctan[Ψ(ln|r′|r0−1)−1]. Matching solutions at r=r0 yields the term generating fingers: pf=P*r0r−1D2[cos(2ωt−2kr+1/4π−δ)]exp[(r 0 −r)α(2ω)−2r0α(ω)] in which δ=arctan[1/4π(ln√2)−1], D2=D(2ω,θ,φ), and P*=Γ(4ρ0c20)−1P20kr02−1/2[(ln√2 )2+(1/4π)2]1/2. For rectangular radiators the zero’s of D1 coincide with the zero’s of D2 therefore fingers do not occur in the case. The total pressure pt=p2+pf. Fingers arise from colinear interaction and have nothing to do with noncolinear scattering of sound by sound which does not exist.
Supersonic acoustic intensity on planar sources
Authors: Williams Earl G.
Published: July 2002

The concept of supersonic acoustic intensity was developed in 1995 out of a need to locate the sources of radiation on an internally excited, submerged cylindrical shell. Supersonic intensity is obtained through signal processing of near-field holographic data to remove the subsonic part of the helical or plane wave spectrum, leaving only the radiating components. This eliminates the out-of-plane circulation of the acoustic intensity vector which results from evanescent waves. The resulting supersonic intensity on the surface is generally only positive, representing outgoing power flow from the surface. Since negative intensity regions of a vibrator are removed, sources of radiation are readily located on the surface of the vibrator. Since the earlier work concentrated on a cylindrical geometry, the theory is presented here for a planar geometry. In many ways the theory for the planar case is simpler and more straightforward. Numerical examples are given for simply supported, baffled plates. It is shown how the supersonic intensity reconstructions, and resulting location of radiating source regions are consistent with the popular theories of corner and edge mode radiation from plates.
A mixed displacement-pressure formulation for poroelastic materials
Authors: Atalla Noureddine , Panneton Raymond , Debergue Patricia
Published: July 2002

Recently, finite element models based on Biot’s displacement (u¯,U¯) formulation for poroelastic materials have been extensively used to predict the acoustical and structural behavior of multilayer structures. These models while accurate lead to large frequency dependent matrices for three-dimensional problems necessitating important setup time, computer storage and solution time. In this paper, a novel exact mixed displacement pressure (u¯,p) formulation is presented. The formulation derives directly from Biot’s poroelasticity equations. It has the form of a classical coupled fluid-structure problem involving the dynamic equations of the skeleton in vacuo and the equivalent fluid in the rigid skeleton limit. The governing (u¯,p) equations and their weak integral form are given together with the coupling conditions with acoustic media. The numerical implementation of the presented approach in a finite element code is discussed. Examples are presented to show the accuracy and effectiveness of the presented formulation.
Silicon capacitive microphones with corrugated diaphragms
Authors: Zou Quanbo , Lin Rongming
Published: July 2002

Several miniature silicon capacitive microphones that are newly developed, including a single-chip fabricated condenser microphone and a floating-electrode-electret microphone, and a double-chip fabricated condenser microphone, will be presented. All these microphones take advantage of the corrugated diaphragm technique, which has been proven to be an excellent technique for highly sensitive structures. This technique has greatly improved the performance of the silicon capacitive microphones, especially the sensitivities and noise levels. High reproducibility of the microphone performance has also been achieved as the result of the reduction of the thin-film initial stress effects on the mechanical membranes. Moreover, the corrugation technique makes it possible to integrate easily the electric circuits on the single chip that contains the microphone. Overall design considerations for various microphones will be presented, followed by the finite-element analyses for the mechanical properties of the diaphragms and backplates. Fabrication processes for these microphones are briefly described. Finally, the experimental results are compared with the calculations. The study shows that the single-chip fabricated condenser and electret microphones with integrated preamplifiers have higher sensitivities or greater potentials compared with other capacitive microphones of the same diaphragm sizes, and many promising applications can be expected.
Evidence against an effect of grouping by spectral regularity on the perception of virtual pitch
Authors: Ciocca Valter
Published: July 2002

Two experiments investigated the role of the regularity of the frequency spacing of harmonics, as a separate factor from harmonicity, on the perception of the virtual pitch of a harmonic series. The first experiment compared the shifts produced by mistuning the 3rd, 4th, and 5th harmonics in the pitch of two harmonic series: the odd-H and the all-H tones. The odd-H tone contained odd harmonics 1 to 11, plus the 4th harmonic; the all-H tone contained harmonics 1 to 12. Both tones had a fundamental frequency of 155 Hz. Pitch shifts produced by mistuning the 3rd harmonic, but not the 4th and 5th harmonics, were found to be significantly larger for the odd-H tone than for the all-H tone. This finding was consistent with the idea that grouping by spectral regularity affects pitch perception since an odd harmonic made a larger contribution than an adjacent even harmonic to the pitch of the odd-H tone. However, an alternative explanation was that the 3rd mistuned harmonic produced larger pitch shifts within the odd-H tone than the 4th mistuned harmonic because of differences in the partial masking of these harmonics by adjacent harmonics. The second experiment tested these explanations by measuring pitch shifts for a modified all-H tone in which each mistuned odd harmonic was tested in the presence of the 4th harmonic, but in the absence of its other even-numbered neighbor. The results showed that, for all mistuned harmonics, pitch shifts for the modified all-H tone were not significantly different from those for the odd-H tone. These findings suggest that the harmonic relations among frequency components, rather than the regularity of their frequency spacing, is the primary factor for the perception of the virtual pitch of complex sounds.
Statistical structures of indoor traffic noise in a high-rise city
Authors: Tang S. K. , Au W. H.
Published: July 2002

Noise measurements were conducted in seven residential flats close to the traffic in Hong Kong. Noise-level time variations and their statistics are discussed. The results of the overall noise level statistics reveal that Gaussian noise-level distribution can only be found under the free traffic-flow condition while some characteristics of gamma noise-level distributions are observed when the flow is of the interrupted type. Short-duration noise-level time variation statistics reveal a well-defined relationship between skewness and kurtosis for each traffic-flow pattern identified. Results also suggest that the Pearson type I and IV distributions are useful for describing the short-duration noise-level distributions.
Piano hammers and their force compression characteristics: Does a power law make sense?
Authors: Giordano N. , Winans J. P.
Published: July 2002

We have studied the force characteristics of a collection of piano hammers, through studies of the acceleration of the hammer head, the force due to the compression of the hammer felt, Fh, and the associated bending of the hammer shank which occurs when a hammer strikes a rigid object. By integration of the acceleration one can estimate the compression of the felt, and thus obtain a force-compression Fh(z) relationship; our results for this function are compared with previous experiments and theoretical models. Close examination of our findings suggests that bending of the hammer shank, and also the time required for the force to be transmitted from the outer edge of the hammer to its core, play significant roles in the hammer dynamics. The data are used to estimate the quantitative impact of these effects on the derived Fh(z) relation. The implications for physical modeling of a piano tone are briefly discussed.
Muscles alive!
Authors: Harris Katherine S.
Published: July 2002

As the Haskins work on speech perception revealed the importance of the contribution to speech perception of time-varying aspects of the acoustic signal, Frank Cooper began a search for techniques to make detailed studies of the dynamic aspects of articulation. While some important work using cinefluorography, by Moll and his associates, had appeared in the 1960s, increasing concern about the hazards of radiation exposure severely limited the collection of substantial bodies of data by such a means. Frank suggested that recording the muscle signals underlying articulator movement, using the techniques suggested by Basmajian for various nonarticulatory systems, might have important advantages. To solve the problem of recording from tongue surfaces, he developed a suction electrode system. However, a later collaboration with researchers from the University of Tokyo using hooked wire electrodes provided better isolation of muscle fiber groups with complex relations to articulator surfaces. This work has led to present day modeling of the relationship of muscles to movement, although substantial problems remain for the work of future generations.
Poly(vinyl Chloride) Melt Rheology and Flow Activation Energy
Authors: Collins Edward A. , Krier Charles A.
Published: July 2002

The melt rheology of poly(vinyl chloride) (PVC) resin has been investigated as a function of shear rate over an 80°C temperature range. The microcrystalline nature of PVC has been observed in the form of a low activation energy (δEγ)L at low temperatures and a high activation energy (δEγ)H at high temperatures. The two distinct flow activation energies suggest different rheological flow units in the low and high temperature regions. It was possible to reduce the shear stress-shear rate curves to a single master curve at 200°C by superposition of temperature and rate of shear.
Restrictions Upon Viscoelastic Relaxation Functions and Complex Moduli
Authors: Christensen R. M.
Published: July 2002

The requirements of nonnegative stored energy, nonnegative rate of dissipation of energy, and fading memory are used to derive restrictions upon the forms of the isotropic relaxation functions and the complex moduli of the linear theory of viscoelasticity. The results suggest some new means of displaying and interpreting mechanical properties.
Low Vision Rehabilitation Service Utilization Before and After Implementation of a Clinical Decision Support System in Ophthalmology
Authors: Guo Xinxing , Boland Michael V. , Swenor Bonnie K. , Goldstein Judith E.
Published: February 2023

Importance

Electronic clinical decision support systems apply clinical guidelines in real time and offer a new approach to improve referral and utilization of low vision rehabilitation (LVR) care.

Objective

To characterize patients and factors associated with LVR service utilization with and without the use of an electronic health record (EHR) clinical decision support system (CDSS) alert.

Design, Setting, and Participants

Quality improvement study using EHR data to compare patients who did and did not utilize LVR service after referral between November 6, 2017, and October 5, 2019, (primary) and to assess overall service utilization rate from September 1, 2016, to April 2, 2021, regardless of referral status (secondary). Participants in the primary analysis were patients at a large ophthalmology department in an academic medical center in the US who received an LVR referral recommendation from their ophthalmologist according to the CDSS alert. The secondary analysis included patients with best documented visual acuity (BDVA) worse than 20/40 before, during, and after the CDSS implementation. Data were analyzed from August 2021 to April 2022.

Exposures

Number and locations of referral recommendations for LVR service according to the CDSS alert in the primary analysis; active CDSS implementation in the secondary analysis.

Main Outcomes and Measures

LVR service utilization rate was defined as the number of patients who accessed service among those who were referred (primary) and among those with BDVA worse than 20/40 (secondary). EHR data on patient demographics (age, sex, race, ethnicity) and ophthalmology encounter characteristics (numbers of referral recommendations, encounter location, and BDVA) were extracted.

Results

Of the 429 patients (median [IQR] age, 71 [53 to 83] years; 233 female [54%]) who received a CDSS-based referral recommendation, 184 (42.9%) utilized LVR service. Compared with nonusers of LVR, users were more likely to have received at least 2 referral recommendations (12.5% vs 6.1%; χ21 = 5.29; P = .02) and at an ophthalmology location with onsite LVR service (87.5% vs 78.0%; χ21 = 6.50; P = .01). Onsite LVR service (odds ratio, 2.06; 95% CI, 1.18-3.61) persisted as the only statistically significant factor after adjusting for patient demographics and other referral characteristics. Among patients whose BDVA was worse than 20/40 before, during, and after the CDSS implementation regardless of referral status, the LVR service utilization rate was 6.1%, 13.8%, and 7.5%, respectively.

Conclusions and Relevance

In this quality improvement study, ophthalmologist referral recommendations and onsite LVR services at the location where patients receive other ophthalmic care were significantly associated with service utilization. Ophthalmology CDSSs are promising tools to apply clinical guidelines in real time to improve connection to care.
Actual conditions and a planning review of collective relocation site from the view of changes in neighborhood relationships: Focusing on the collective relocation project for disaster prevention in Koizumimachi district, Kesennuma city, Japan
Authors: Tsubouchi Ken , Mori Suguru , Nomura Rie
Published: February 2023

This article aims to review a large‐scale collective relocation planning of the Koizumimachi district, which implemented concept of the Radburn housing design to mitigate the environmental transition after the Great East Japan earthquake. Based on actual conditions through 2‐year investigations after resettlement, it demonstrates that residents utilized the relocation site adapting to different issues of the community relocation: continuity of the previous district's neighborhood relationships and constructions of new ones due to integrated multiple districts. On the other hand, there is a mismatch between total housing land design and individual housing reconstructions in point of the correspondence between entrance direction and cul‐de‐sac.
Exploiting the Thermotropic Behavior of Hydroxypropyl Cellulose to Produce Edible Photonic Pigments
Authors: Ming Siyi , Zhang Xiaotian , Chan Chun Lam Clement , Wang Zhen , Bay Mélanie M. , Parker Richard M. , Vignolini Silvia
Published: February 2023

Hydroxypropyl cellulose (HPC) is a widely commercialized cellulose derivative. While it is typically used as a binder or stabilizer for foods and pharmaceuticals, it can also form a cholesteric liquid crystal in aqueous solution. Moreover, at high HPC concentrations this lyotropic and thermotropic mesophase is known to reflect structural color. However, it remains a challenge to retain this vibrant coloration into the solid state. Herein, by combining the emulsification of a HPC mesophase with drying at elevated temperature, solid microparticles are produced that can reflect color across the visible spectrum, from blue to green and red. This method provides a facile and scalable pathway to fabricate structurally colored, edible pigments, which can displace existing synthetic additives used in a wide range of foods and cosmetics.
Fluorescent Flippers: Small‐Molecule Probes to Image Membrane Tension in Living Systems
Authors: Chen Xiao‐Xiao , Bayard Felix , Gonzalez‐Sanchis Nerea , Pamungkas Khurnia Krisna Puji , Sakai Naomi , Matile Stefan
Published: February 2023

Flipper probes have been introduced as small molecule fluorophores to image physical forces, that is, membrane tension in living systems. Their emergence over one decade is described, from evolution in design and synthesis to spectroscopic properties. Responsiveness to physical compression in equilibrium at the ground state is identified as the ideal origin of mechanosensitivity to image membrane tension in living cells. A rich collection of flippers is described to deliver and release in any subcellular membrane of interest in a leaflet‐specific manner. Chalcogen‐bonding cascade switching and dynamic covalent flippers are developed for super‐resolution imaging and dual‐sensing of membrane compression and hydration. Availability and broad use in the community validate flipper probes as a fine example of the power of translational supramolecular chemistry, moving from fundamental principles to success on the market.
A novel epoxy vitrimer with low dielectric constant at high‐frequency
Authors: Zhou Gang , Zhang Jian , Wang Ziqing , Ning Na , Huang Yuan , Wei Yi
Published: February 2023

Vitrmers are a new type of functional resins having the majority of published studies focused on reprocessing, recycling, healing, welding, and shape memory, and their mechanical properties are extensively investigated. While most of the intended applications of these vitrimers are related to elastomers and composites, little research has been published on their dielectric properties and their applications in tele‐communication fields. Herein, dielectric property of four typical epoxy‐anhydride vitrimers were investigated. Vitrimer catalyzed by Zn(Acac)2(zinc acetylacetonate) show excellent re‐processability, which were further improved by introducing MTHPA (methyl terahydrophthalic anhydride) and styrene maleic anhydride (SMA) polymers. The modified epoxy vitrimer shows favorable Tgof 106°C and low dielectric constant (2.77 at 10 GHz). Notably, the modified vitrimer are still re‐processable and degradable due to the dynamic ester bonds, and maintains its dielectric and thermal performances after being reprocessed.