bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequence analyses of variable cytomegalovirus genes for distinction between breast milk– and transfusion‐transmitted infections in very‐low‐birth‐weight infants
Authors: Furui Yasumi , Yamagishi Naoji , Morioka Ichiro , Taira Rikizo , Nishida Kosuke , Ohyama Shohei , Matsumoto Hisayuki , Nakamachi Yuji , Hasegawa Takashi , Matsubayashi Keiji , Nagai Tadashi , Satake Masahiro
Published: October 2018

BACKGROUND

Cytomegalovirus (CMV) transmission to very‐low‐birth‐weight infants (VLBWIs) sometimes induces serious clinical symptoms. Although breast milk is considered a major source of transmission, transfusion‐transmitted CMV (TT‐CMV) infection is often suspected when CMV disease develops after transfusion. Thus, it is clinically important to distinguish between transfusion‐transmitted and breast milk–transmitted CMV infections.

STUDY DESIGN AND METHODS

Study A: The incidence of acquired CMV transmission was prospectively investigated in 65 VLBWIs. Study B: To determine the transmission routes in 18 TT‐CMV–suspected VLBWIs who had been reported in our hemovigilance system, we performed polymerase chain reaction for CMV DNA in fed breast milk and/or repository blood samples related to transfused leukoreduced blood products. Furthermore, we evaluated the identity of CMV strains in patients' urine/blood samples and fed breast milk by sequence analyses of variable CMV genes UL139 and UL146.

RESULTS

Study A: Acquired CMV infection was found in 4 of 65 VLBWIs (6.2%). Study B: CMV DNA was detected in fed breast milk for 12 of 14 TT‐CMV–suspected cases, for which breast milk was available. Furthermore, CMV DNA sequence‐matching rates between fed breast milk and patients' urine/blood for both UL139 and UL146 genes were 100% or nearly 100% in 11 patients. In contrast, repository blood samples for 11 of 14 patients were CMV DNA negative.

CONCLUSION

CMV is principally transmitted through breast milk in VLBWIs. The risk of TT‐CMV seems to be extremely low when using leukoreduced blood products. Sequence analyses of the variable CMV genes are useful for evaluating CMV transmission routes.
Has the crisis affected Spanish investment strategy abroad? A spatial panel data approach
Authors: Gutiérrez‐Portilla Paula , Maza Adolfo , Villaverde José
Published: October 2018

This paper investigates whether the Spanish investment strategy abroad has been affected by the Great Recession. Applying a panel spatial Durbin model for two sample periods, pre‐crisis (1996–2007) and crisis (2008–14), our findings indicate that Spanish foreign direct investment (FDI) strategy has been indeed markedly altered by the global economic crisis. Complex‐vertical FDI motives prevailed over the pre‐crisis period, whereas horizontal FDI did so over the crisis. These results are robust to the use of sectoral FDI data and alternative specifications of the spatial weight matrix.
Fuzzy‐based gaps assessment of flood disaster risk reduction management systems in Metro Manila, Philippines
Authors: Gilbuena Romeo , Kawamura Akira , Medina Reynaldo , Amaguchi Hideo
Published: October 2018

Planning and prioritization in flood disaster risk reduction (FDRR) is critical and often tedious to both planners and decision‐makers. In Metro Manila, Philippines, flooding is a perennial problem that requires regular assessments and updating of its municipal‐based FDRR management systems. A simple, but practical approach may prove useful in the identification of priority schemes, especially when the need for improvement is urgent and resources are limited. This study provides a simple quantitative approach to gaps assessment for FDRR management systems using a fuzzy multiattribute decision‐making technique. This is demonstrated by utilizing the stakeholders’ perceptions and field information obtained during the aftermath of the tropical storm Ketsana in 2009. Study results show that the gaps can be quantified and ranked to establish the priority schemes for the improvement of the FDRR management systems in Metro Manila, focusing mainly on the following FDRR management systems: prevention, preparedness, response and disaster recovery.
Applications of the hyperbolic Ax–Schanuel conjecture
Authors: Daw Christopher , Ren Jinbo
Published: October 2018

In 2014, Pila and Tsimerman gave a proof of the Ax–Schanuel conjecture for the$j$-function and, with Mok, have recently announced a proof of its generalization to any (pure) Shimura variety. We refer to this generalization as the hyperbolic Ax–Schanuel conjecture. In this article, we show that the hyperbolic Ax–Schanuel conjecture can be used to reduce the Zilber–Pink conjecture for Shimura varieties to a problem of point counting. We further show that this point counting problem can be tackled in a number of cases using the Pila–Wilkie counting theorem and several arithmetic conjectures. Our methods are inspired by previous applications of the Pila–Zannier method and, in particular, the recent proof by Habegger and Pila of the Zilber–Pink conjecture for curves in abelian varieties.
The Manin constant in the semistable case
Authors: Česnavičius Kęstutis
Published: October 2018

For an optimal modular parametrization$J_{0}(n){\twoheadrightarrow}E$of an elliptic curve$E$over$\mathbb{Q}$of conductor$n$, Manin conjectured the agreement of two natural$\mathbb{Z}$-lattices in the$\mathbb{Q}$-vector space$H^{0}(E,\unicode[STIX]{x1D6FA}^{1})$. Multiple authors generalized his conjecture to higher-dimensional newform quotients. We prove the Manin conjecture for semistable$E$, give counterexamples to all the proposed generalizations, and prove several semistable special cases of these generalizations. The proofs establish general relations between the integral$p$-adic étale and de Rham cohomologies of abelian varieties over$p$-adic fields and exhibit a new exactness result for Néron models.
On two arithmetic theta lifts
Authors: Ehlen Stephan , Sankaran Siddarth
Published: October 2018

Our aim is to clarify the relationship between Kudla’s and Bruinier’s Green functions attached to special cycles on Shimura varieties of orthogonal and unitary type, which play a key role in the arithmetic geometry of these cycles in the context of Kudla’s program. In particular, we show that the generating series obtained by taking the differences of the two families of Green functions is a non-holomorphic modular form and has trivial (cuspidal) holomorphic projection. Along the way, we construct a section of the Maaß lowering operator for moderate growth forms valued in the Weil representation using a regularized theta lift, which may be of independent interest, as it in particular has applications to mock modular forms. We also consider arithmetic-geometric applications to integral models of$U(n,1)$Shimura varieties. Each family of Green functions gives rise to a formal arithmetic theta function, valued in an arithmetic Chow group, that is conjectured to be modular; our main result is the modularity of the difference of the two arithmetic theta functions. Finally, we relate the arithmetic heights of the special cycles to special derivatives of Eisenstein series, as predicted by Kudla’s conjecture, and describe a refinement of a theorem of Bruinier, Howard and Yang on arithmetic intersections against CM points.
Guard Digits vs. Roundoff Error vs. Overall Uncertainty
Authors: Denker John , Smith Larry
Published: October 2018

Roundoff error is an error. It can be dramatically reduced by the use of additional low-order digits, i.e. guard digits. Although the significant-figures idea in its standard form is incompatible with guard digits, this problem can be neatly solved by underlining the last “significant” digit, and then appending guard digits to the right of there. This clarifies the distinction between roundoff error and overall uncertainty while preserving compatibility with sig figs. The focus here is on reducing roundoff error; we defer discussion of most other contributions to the uncertainty.
Gravitational Model of a p-n Junction
Authors: Henrich Victor E.
Published: October 2018

When students first encounter energy bands in semiconductors, and how the properties of simple semiconductor devices such as the p-n junction diode depend on them, the concept can be a bit difficult to grasp. As part of an undergraduate physics course for non-STEM majors that includes semiconductors and simple devices based on the p-n junction, a gravitational analog of the device, using an inclined plane and ball bearings (Fig. 1), has helped students understand the concept. The model has also proved useful in introductory solid-state physics and semiconductor device courses.
An Indoor Magnetic Exploration Survey
Authors: Littleton Joshua A. H. , Secco Richard
Published: October 2018

Magnetism is traditionally taught within the subject of electromagnetism at the undergraduate and graduate levels in physics courses, with the goal of establishing a solid foundation of the underlying physical mechanisms before advancing to more specialized topics. Oftentimes, a laboratory component of these courses involves practical, hands-on exercises that include, e.g., characterization of magnetic properties of materials and dipoles, measuring the vertical and horizontal component of a magnetic field generated by power supplies, or measuring the EMF induced in a wire coil due to a changing magnetic field. Here, we provide a complement to these activities with a discovery exercise akin to an outdoor magnetic field survey, one that leverages the ready availability of strong small rare earth magnets (“neo-magnets”).
Two Simple and Inexpensive Desk-Top Experiments with Vibrations of a Uniform Beam
Authors: Oliver Douglas L.
Published: October 2018

The study of vibration in uniform beams provides physics teachers with a platform by which a broad range of physics vibration-related topics can be explored without expensive and specialized equipment. This paper presents two laboratory exercises related to lateral beam vibrations. These exercises use beam theory coupled with free sound-analysis software (Raven Lite 2.0), and are appropriate for both high school and first-year college physics students. In this paper, the uniform beam is a slender tube with unsupported (or free) ends—such as a wind chime.
Acoustical safety as important as comfort and wellness
Authors: Satoh Fumiaki
Published: October 2018

Needless to say, the points of comfort and wellness are very important for the evaluation of spaces. In addition, how about the point of safety? This doesn’t mean structural safety of buildings or safety to prevent crimes. For example, the luck of intelligibility of evacuation announcement in an emergency, this is an unsafe situation. It’s a matter of “acoustical safety.” To use absorption materials in spaces is very effective on the point of comfort and it leads to be better condition on the point of safety at the same time; however, the point of “acoustical safety” should be emphasized more. In the current situation in Japan, the consideration of using absorption materials for comfortable and safe spaces doesn’t seem to be enough. This is a common understanding in our Japanese researchers on architectural acoustics. Therefore, a committee in Architectural Institute of Japan published a book in order to be popular using absorption materials. In this presentation, the contents about the book and the discussions up to publication will be introduced, in addition to some works on acoustical safety.
Noise analysis of urban change in the structure of health care up to the present from the beginning of the Republican era in Turkey: Case studies from Ankara Numune Hospital
Authors: Kocyigit Filiz B. , Bulhaz Cagri , Resuloglu Cilga
Published: October 2018

This research investigates the acoustical characteristics of hospitals' building environment of the Republican period and the contemporary era. Ankara Numune Hospital has been selected as a sample for research. The acoustical effect of the evolution of urban planning on the edges of Numune hospital in Capital city Ankara is analyzed. Green areas surrounded the boundaries of Numune hospital in the 1930s, whereas nowadays these green areas have been narrowed during decades. Social, political, and economic relationships changed as a result of urbanization in Turkey. Urban planning decisions affected the development, particularly the (historic) city center of Ankara where Numune hospital, the oldest hospital in Ankara, is located. Results, at the research, include equivalent sound pressure levels (Leq) as a function of location, frequency, and time of day. It appears that there are important problems in measurements taken at the entrance and at the hospital periphery and at different days and times. Average equivalent sound levels are in the 50–60 dB (A) range for 1 min, ½, and 24 h averaging time periods. The spectra are generally flat over the 63–2000 Hz octave bands, with higher sound levels at lower frequencies, and a gradual roll off above 2000 Hz. Many units exhibit little if any reduction of sound levels in the nighttime.
Just noticeable difference of masker to enhance privacy in an open-plan office
Authors: Nadiroh Ainun , Arifianto Dhany
Published: October 2018

If a background conversation (masker) is easy to follow, then a worker at a workstation in an open-plan office will be distracted and annoyed. The aim of this study was if the mixture of the background conversations statistical distribution close to Gaussianity, then regardless the loudness level, the intelligibility will be decreased. On the other hand, the privacy at the workstation will be increased due to the loudness level of the background conversation. To assess the privacy level in a simulated open-plan office, we propose Just Noticeable Difference (JND) of the masker. The measurement was conducted in two workstations laboratory with 64 square meters for each workstation in which three conditions (male-female, all male, and all female speakers) of babble noise was built in one of them. The other workstation was simulated with single speech sound to observe speech privacy in the presence of the masker. We used objective measures to assess the intelligibility and the privacy of the workstation. The results suggest that the saliency of the masker depends on the fundamental frequency difference (dominant speaker). The higher saliency of the masker will cause the lower of the privacy of the other workstation.
Assessing ontogenetic change in acoustic pressure sensitivity in larval fishes through modelling
Authors: Salas Andria K. , Wilson Preston S. , Fuiman Lee A.
Published: October 2018

Detecting acoustic pressure can improve a fish’s survival and fitness through increased sensitivity to environmental sounds. Pressure detection results from the interactions between the swim bladder and otoliths. In larval fishes, those interactions change rapidly as growth and development alter bladder dimensions and otolith-bladder distances. We used computed tomography imagery of lab-reared larval red drum (Sciaenops ocellatus) in a finite-element model to assess ontogenetic change in acoustic pressure sensitivity in response to a plane wave at frequencies within the range of detection by fishes. We compared the acceleration at points on the sagitta, asteriscus, and lapillus when the bladder was air-filled to results from models using a water-filled bladder. For larvae of 8.5–18 mm, the air-filled bladder amplified otolith motion by a factor of 54–3485 times that of a water-filled bladder at 100 Hz. Otolith-bladder distances increased with standard length, which decreased amplification. The concomitant rapid increase in bladder volume partially compensated for the effect of increasing otolith-bladder distances. Using idealized geometry, we found that the backbone and ribs have a negligible influence on bladder motion. Our results help clarify the auditory consequences of ontogenetic changes in swim bladder morphology and otolith-bladder relationships during larval stages.
Experimental investigation of a robust algorithm for unambiguous source directionalization by sharks
Authors: Rogers Peter H. , Martin James S. , Montgomery John C. , Radford Craig A.
Published: October 2018

All fish can detect the three vector components of particle motion, enabling them to determine source bearing, but particle motion alone cannot resolve which direction is towards the source and which direction is away (i.e., there is a 180° ambiguity). However, fish with swim bladders can also detect acoustic pressure which enables such fish to resolve this 180° ambiguity. Proposed processing algorithms, though, often employ unrealistic restrictions such as sinusoidal time dependence and free-field conditions. We propose a robust algorithm for determining the unambiguous source direction by a fish that can detect acoustic pressure. The method is based on the time-averaged acoustic intensity vector (the time-integral of the product of pressure and particle velocity). This non-oscillatory quantity points in the direction of energy flow and hence directly away from the source. The algorithm has the advantage of being applicable to signals with any time dependence, in any propagation environment. For sharks, which do not have swim bladders, we hypothesize that the vertical component of particle acceleration can be substituted for pressure, provided that the shark is sufficiently close to the water surface. We test the validity of this hypothesis by determining the direction to the source for reef noise, a biologically relevant signal, and boat noise in a range-varying shallow water environment.
Toward predictive understanding of the rapidly evolving Arctic Ocean—An overview
Authors: Maslowski Wieslaw , Lee Younjoo , Kinney Jaclyn , Osinski Ronbert , Kamal Samy
Published: October 2018

Some of the most rapid climate changes on the planet are experienced in the Arctic. In particular, the Arctic has been warming at a quicker pace than any other place on Earth, what is recognized as Arctic Amplification (AA). This warming has been most visibly manifested through a declining perennial sea ice cover, increasing the potential for its transition from the permanent toward a seasonal coverage. Those changes also affect air-sea heat fluxes and amplify ice-albedo feedback, which strongly influences ocean’s absorption of solar radiation. In addition, they also alter the Arctic Ocean acoustical regime, as the thinning sea ice moves faster and deforms easier, while its reduced coverage allows increased momentum transfer from the atmosphere to the upper ocean. This talk will provide an updated overview of the recent changes and trends in the Arctic Ocean of relevance to acoustical oceanography. We will focus on the evolution of the upper ocean stratification and water masses, mesoscale processes, and their linkages to the changing regime of the sea ice cover from multi-year to first-year sea ice. Also, the latest advancements and outstanding challenges in modeling and prediction of Arctic climate change at sub-seasonal to interannual time scales will be discussed.
The 2016–2017 deep-water Canada Basin Acoustic Propagation Experiment (CANAPE): An overview
Authors: Worcester Peter F. , Dzieciuch Matthew A. , Colosi John A. , Proshutinsky Andrey Y. , Krishfield Richard A. , Nash Jonathan D. , Kemp John N.
Published: October 2018

The Arctic Ocean is undergoing dramatic changes in the ice cover and ocean structure. The 2016–2017 deep-water Canada Basin Acoustic Propagation Experiment (CANAPE) was designed to understand the effects of changing Arctic conditions on low-frequency, long-range propagation and ambient noise. Five acoustic transceivers were deployed in a pentagon with a sixth transceiver at the center, forming an ocean acoustic tomography array with a radius of 150 km in the central Beaufort Sea. The transceivers had broadband sources centered at approximately 250 Hz located at 175-m depth in the Beaufort Duct and 15 Hydrophone Modules spanning 135 m located above the sources. A Distributed Vertical Line Array receiver with 60 Hydrophone Modules spanning 540 m was embedded within the tomographic array to provide measurements of acoustic time fronts and their fluctuations. The tomographic array was largely in open water during summer, in the marginal ice zone as it transitioned across the array during the spring and autumn, and under complete ice cover during winter. The tomographic data, together with moored data from Sea-Bird MicroCATs, Acoustic Doppler Current Profilers, ice-profiling sonars, and precision temperature sensors, will help characterize the large-scale oceanographic variability throughout the year, aiding in the interpretation the acoustic data.
Overview of one year acoustical oceanography measurements on Chukchi shelf during Shallow Water Canada Basin Acoustic Propagation Experiment 2016–2017
Authors: Badiey Mohsen , Eickmeier Justin , Lin Ying-Tsong , Turgut Altan , Pecknold Sean , Ballard Megan S. , Sagers Jason D. , Worcester Peter F. , Dzieciuch Mathew , Whitt Christopher
Published: October 2018

A multi-institutional, acoustical oceanography experiment was conducted from October 2016 through November 2017 on the Chukchi continental shelf covering 100–700 m isobaths. Parallel to a deep-water experiment conducted during the same period, the Shallow Water Canada Basin Acoustic Propagation Experiment (SW CANAPE) was designed to assess basin scale acoustic signals on the shelf region while detailed oceanographic dynamic of the shelf break region, particularly the upwelling and other dynamic of the upper 500 m water column, was measured simultaneously. Multiple arrays of oceanographic sensors including upward looking ice profiler, current profiler, temperature, conductivity, and pressure profiles measured temporal and spatial dynamics of 500 m upper ocean in connection with acoustic measurements. Distributed in a 30 km2 area north of Barrow Alaska, vertical line arrays including an L-shaped array, covered upper 200 m of the water column. Two acoustic sources placed at 148 m and 193 m depths on the shelf emitted broadband acoustic signals in frequency bands (700–1100 Hz, and 1400–4000 Hz) along and across the shelf while the sound speed and current profile and surface ice were being measured continuously. Deep water low frequency signals were also recorded. This talk provides an overview of the SW CANAPE experiment and highlights some of the detailed measurements. [Work supported by ONR.]
Deep learning for automated detection of B-lines in lung ultrasonography
Authors: J. G. van Sloun Ruud , Demi Libertario
Published: October 2018

The application of ultrasound imaging to the diagnosis of lung diseases is gaining attention. Of particular interest are several imaging-artifacts, e.g., A and B line artifacts. A-lines are hyperechoic horizontal lines, which are substantially visualized across the entire image and parallel to pleural-line. They represent the normal pattern of the lung if pneumothorax is excluded. Differently, B-line artifacts correlate with pathology and are defined as hyperechoic vertical artifacts, which originate from a point along the pleura-line and lie perpendicular to the latter. Their presence has been linked to an increase in extravascular lung water, interstitial lung diseases, non-cardiogenic lung edema, interstitial pneumonia and lung contusion. In this work, we describe a method aimed to support the clinicians by automatically identifying the frames of an ultrasound video where B-lines are found. To this end, we employ modern deep learning strategies and train a fully convolutional neural network to perform this task on b-mode images of dedicated ultrasound phantoms (Demi et al., Sci. Rep. 2017). We moreover calculate neural attention maps that visualize which components in the image triggered the network, thereby offering simultaneous localization. Future work includes characterization of the detected B-lines to enable adequate phenotyping of various lung pathologies.
Ultrasound assessment of pulmonary edema using multiple scattering
Authors: Mohanty Kaustav , Blackwell John , Masuodi Behrooz , Ali Mir H. , Egan Thomas , Muller Marie M.
Published: October 2018

Ultrasound imaging in the lungs is challenging because of air-filled alveoli which induce multiple scattering. Pulmonary edema is characterized by increased extravascular lung water, which causes acute dyspnea. There is an urgent need from pulmonologists to non-invasively quantify pulmonary edema, in order to monitor response to treatment. The present methodology takes advantage of multiple scattering and calculates the scattering mean free path (L*) for the quantitative assessment of pulmonary edema. L* is a semi-local property, which could be correlated to the amount of fluid buildup in the lung. Pulmonary edema was induced in 4 Sprague-Dawley rats using ischemia reperfusion injury. Following a sternotomy, L* was calculated from the time evolution of the backscattered incoherent intensity using an L11-4v linear array connected to a Verasonics scanner. Ex-vivo data were also acquired for 2 edematous pig lungs. For measurements, the left lung was edematous whereas the right lung was treated as control. Significant differences (p<0.001) were found between control (L* = 330±89μm) and edema (L* = 876±179 μm) for in-vivo rats. For ex-vivo pig lungs, L* was found to be 190±84 μm for control and 1074±361 μm for edema. This suggests the potential of L* for the assessment of pulmonary edema.
Observation of acoustic fountain generation by diagnostic ultrasound shear wave elastography
Authors: Patterson Brandon , Miller Douglas
Published: October 2018

High-intensity focused ultrasound has been shown to drive fountains and atomization at liquid-gas and tissue-gas interfaces. Though these phenomena are not well studied for diagnostic ultrasound, they have been hypothesized to play a role in diagnostic ultrasound-induced pulmonary capillary hemorrhage (PCH). We demonstrate that push pulses used in diagnostic shear wave elastography (SWE) also cause fountaining and atomization at water-air and blood-air interfaces. A focused ultrasound transducer (SSI SL15-4), was aimed upward, through water, at an air interface. An SWE pulse sequence, including four push pulses (amplitude ≤ 8.6 MPa, pulse duration ≅ 650 ms, and center frequency ≅ 5.0 MHz), was initiated. The interface was photographed at 20k fps and four successive fountains were observed. Fountains heights up to 12 and 11 mm were observed for water and blood respectively and ejected water droplets traveled up to 30 cm above the surface. The spacing of the four fountains was measured to be the same as the spacing of four PCH areas observed on rat lungs exposed to the same pulse sequence. Concurrent studies should reveal the relative efficacy of PCH induction from SWE and normal pulse echo and Doppler imaging.
Comparing two inverse array methods for source reconstructions of noise radiated from a high-performance jet aircraft
Authors: Ward Jacob A. , Leete Kevin M. , Gee Kent L. , Van Komen David F. , Neilsen Tracianne B. , Wall Alan T. , Downing Micah , James Michael M.
Published: October 2018

Because direct flow measurements of tactical aircraft jet engines are not currently possible, acoustic source characteristics are instead inferred from array processing. This paper compares two array processing methods using the same array data from a high-performance military aircraft. Hybrid beamforming (HBF) and multisource statistically optimized near-field acoustical holography (M-SONAH) have both been used previously for frequency-dependent jet noise source characterization, but are compared here for the same input data. A 71-element linear array of equally spaced microphones was placed approximately parallel to the shear layer covering a distance of 32 m. Complex pressures obtained from this array served as the input to both methods. Favorable agreement in terms of maximum source location, source shape, and source extent was seen between the two methods' respective results. While the methods continue to have their relative strengths and reasons for use, this favorable agreement indicates that an improved understanding of military jet noise sources has been achieved. [Work supported by an AFRL SBIR.]
Sensitivity of acoustic predictions on the mesh size of large-eddy simulation of supersonic jet
Authors: Jang Inman , Ohm Won-Suk , Joo H. S. , Shin S.-J. , Park J. W.
Published: October 2018

Intense noise produced by the supersonic jet plume from a rocket can cause damage to its structural system and even a failure during launch. In order to predict the acoustic loading by rocket jet noise, large-eddy simulation (LES) is commonly employed for analysis of the jet flow field that is subsequently used as a source condition for predicting the acoustic field. Although desirable from the accuracy standpoint, LES of a supersonic jet is often burdened by an overwhelming computational cost in both runtime and memory. In this talk, we discuss the sensitivity of acoustic predictions on the spatial resolution of LES, and propose a guideline for reducing the mesh requirement. . Here, the flow field of a supersonic jet is calculated using a hybrid RANS/LES scheme on meshes of different sizes, and is fed into the Helmholtz-Kirchhoff integral for prediction of the acoustic farfield. Changes in overall sound pressure level (OASPL) and directivity of the Mach radiation are monitored as the LES mesh varies in size. The study suggests that (a) the accuracy of the acoustic prediction is not much affected by the use of a coarser mesh to a certain extent and (b) the resulting improvement in computation speed and economy thus outweighs the loss of details in LES, given the prediction of acoustic loading as the ultimate goal. (This work was conducted at High-Speed Vehicle Research Center of KAIST with the support of the Defense Acquisition Program Administration and the Agency for Defense Development under Contract UD170018CD.)
The problem of parallax when using high speed cameras for measurement
Authors: Russell Daniel A.
Published: October 2018

When using a high-speed camera as a recording device to measure the displacement or position of an object, the problem of parallax must be properly accounted for, or significant errors in measured positions can occur. In this paper, an experiment to measure the elastic properties of several golf balls of varying construction is described. The goal of the experiment was to verify whether a correlation exists between a ball’s coefficient-of-restitution (COR) and the frequency of its lowest structural vibration mode. Balls were dropped from a height onto a rigid surface and the COR was obtained by taking the ratio of speeds just before and just after impact with the rigid surface. Balls were dropped and bounced in front of a scale with fine graduation markings. Video recorded with a high-speed camera was processed using tracking software to measure the ball’s position and velocity as a function of time. However, parallax due to the camera field of view introduced significant error into measurement of position and velocity. This paper describes how the parallax error was accounted for in the video-recorded measurements in order to obtain data that matched theoretical expectations.
A method for measuring the dynamic parameters by extracting the incident
Authors: Hou Hong , Wei Zhengyu , Gao Nansha , Yang Jianhua
Published: October 2018

The complex Young’s modulus of viscoelastic materials can be determined by monitoring the propagation of a traveling burst in a thin bar, which is called wave-speed method. While the test samples are always too short to make the incident wave for lower-frequency signals be detected, which lead to low-frequency test is difficult using this method. To solve this problem, a method of extracting the incident wave is presented in this paper. A pulse wave is generated by the exciter and is used to force the longitudinal vibration of a viscoelastic thin bar. The velocities of the two ends of the thin bar are measured by two laser Doppler vibrometers. The incident waves at both of the two ends of the sample can be easily extracted, and the dynamic parameters of the sample can be obtained by the ratio of the vibration velocities of them. This method expands the experimental frequency range of the wave-speed method and the measured results agree well with that of commercial viscoelastic instrument.
Machine learning in acoustic applications with wave physics models, a tutorial
Authors: Li Weichang
Published: October 2018

Through recent decades of intensive research, machine learning has established its great potential in areas such as social networking, e-commerce, computer vision, natural language processing, and robotics. Recently, it has also started to capture the attention of the acoustic research community where the problems have wave physics basis and the research has focused on related areas such as signal/image processing. This is evident in the significantly increased number of related papers presented at recent ASA meetings. The challenge appears to concerning several aspects: i) What types of acoustic applications can be formulated as ML problems in a way that could provide interesting results and potentially better performance? ii) What would be the relationship between wave physics models and machine learning methods? iii) What is the dataset requirement of machine learning that is potentially different from say, signal processing techniques, and what implications it might have on experimental design, data collection, and annotation? ii) What are the areas that might not have much benefit from taking a machine learning approach? This tutorial will present a number of acoustics/geophysics application examples along with their analogs in canonical machine learning applications, as an attempt to illustrate possibilities and limitations.
The machine learning aspects in building the global smartphone seismic network
Authors: Kong Qingkai , Allen Richard
Published: October 2018

MyShake is a global crowdsourcing smartphone seismic network to monitor and detect earthquakes. After it got released to the public in 2016, we arrived at more than 300,000 downloads with more than 800 detected earthquakes globally within 2 years. Machine learning plays a critical role in MyShake that makes everything happen. In this presentation, I will present the details of how we use the artificial neural network to distinguish earthquakes from the human activity movements recorded on a single phone in real-time. This includes how we do the data acquisition, pre-processing the data, addressing imbalanced datasets, feature engineering/selection, and evaluating the model. I will also talk other machine learning aspects in the MyShake network including the convolutional neural network that we built on the server to further classify the whole waveforms to find that caused by earthquakes, the adversarial machine learning for securities of the system, dealing with the dynamically changing network, training customized model for each user etc. These machine-learning applications in MyShake illustrate the power of combining data science and geophysics and provide good examples of how do we better facilitate the interactions of the two fields.
Total independent energy distance—A measure for choosing efficient spectrogram resolutions
Authors: Taft Benjamin N.
Published: October 2018

This paper describes a quantitative method for choosing the most efficient frequency resolution and window overlap when creating spectrograms. The method calculates the Euclidean distance, d, and the coefficient of determination, R2, between a pair of successive power spectra in the spectrogram. The quantity d × (1—R2) is the Euclidean distance between the windows' power spectra, discounted by the information redundancy between the spectra. The Total Independent Energy Distance (TIED) is then the sum of those distances along the entire spectrogram. The effectiveness of TIED is computed for a variety of artificial signals including white noise, sawtooth waveforms that vary in their frequency resolution, pulse trains, and amplitude-modulated signals that vary in their time distribution, and frequency sweeps that vary in both. The TIED is then calculated for human speech, bird song, and insect buzzes, demonstrating that it provides quantitative support to time- and frequency-resolutions for the spectrograms that closely adhere to the traditional resolutions that have been arrived at through generations of human pattern recognition.
Dereverberation binaural source separation using deep learning
Authors: Arifianto Dhany , Farid Mifta N.
Published: October 2018

This paper reported a deep-learning based binaural separation using gammatone-frequency cepstral coefficient (GFCC) and multi-resolution cochleagram (MRCG) as spectral features and interaural time difference (ITD) and interaural level difference (ILD) as spatial features. A binary mask was estimated by deep neural network (DNN) binary classifier that used the features as a training data and ideal ratio mask (IRM) as a training target. In the experiment, a male speaker as a target speech at azimuth 0o and a female speaker as a masker speech at azimuth 30o, 20o, 10o, and 5o in rooms with 0.32, 0.47, 0.68, and 0.89 s reverberation time (RT60). As a training process, 50 mixtures were used for each condition experiment. The classifier contained two hidden layers, 200 binary neurons and 50 epoch, and Restricted Boltzmann Machine (RBM) was used as pre-training process. The RBM and the classifier learning rate was 1 up to 0.001 from epoch 1 to epoch 50. The sound quality results indicated by 88% intelligibility of STOI method which means that the separated sound is easily understood by the listener. The MOS value is 2.8 which means the sentence is clear but spectral distortion is slightly annoying.
Proof of concept: Machine learning based filling level estimation for bulk solid silos
Authors: Sivasothy Paaranan , Andres Matthias , Corbin Gregor
Published: October 2018

Rigid silos are often under pressure and filled with hazardous materials. Therefore, in very few cases their level can be checked visually. For example, the level of mobile bulk solids silos, which are often used on construction sites, is checked by a worker throwing a stone against the silo and uses the sound to estimate the invisible silo cavity. This method is subjective and shows great errors based on experience. The proposed method should implement this principle robustly by machine application. A sensor unit is to give a mechanical impulse to the outer silo wall with a percussion mechanism and record the resulting sound with a microphone. Just as a human being is able to make an experience-based statement about the filling level of the silo over the growing amount of sounds heard, different machine learning approaches are to be considered in order to imitate this procedure. Machine learning approaches usually aim to find patterns between different sizes. A strongly approximated mathematical model will be used to prove that there is a noisy but demonstrable direct correlation between the level and the acoustic impulse response. This should justify future efforts to find suitable machine learning methods for this application.
Geospatial estimation of noise levels between sparsely distributed sensor nodes using machine learning
Authors: Blevins Matthew G. , Ochi Gordon M.
Published: October 2018

Monitoring noise levels over large areas is typically limited by the number of sensor nodes. While previous studies have been able to accurately estimate noise levels using densely distributed sensors in confined spaces, such as along roads in urban areas, estimating noise levels with relatively few sensors spaced over a large area remains a challenging problem. Point sampling of noise levels due to single noise events is also limited by the models used to estimate between sensor locations and their inherent assumptions. To address these limitations we propose nonlinear, adaptive, and robust tools to estimate levels between sensor nodes based on machine learning. Random forests, support vector machines, and Gaussian processes are explored along with conventional geostatistical methods such as ordinary kriging. These methods are trained and evaluated on data from both measurement and simulation of blast noise on military testing and training ranges. The performance of the methods is evaluated using cross validation and root-mean-square-error.
Variability in surface reverberation observed with a high-frequency obstacle avoidance sonar
Authors: Trevorrow Mark V.
Published: October 2018

Sea-surface reverberation and, in particular, near-surface bubble backscatter, can pose a strong limitation on HF sonar performance. Recent high-frequency obstacle-avoidance sonar measurements showed significant variability in low grazing angle sea-surface reverberation. The sonar used in these sea-trials operated at 90kHz covering a 90-degree angular sector with 128 beams at ranges up to 600 m. It was projected horizontally forward from a ship at a depth of 3.5 m in deep water. The statistics of the background reverberation under Sea-State 3 to 4 conditions were investigated. The time- and spatially averaged background reverberation levels agreed with well-known APL-UW models. However, the instantaneous reverberation amplitudes exhibited non-Rayleigh statistical distributions, in better agreement with log-normal distributions. This variability was attributed to scattering patchiness and surface wave effects.
Statistical optimal filtering method for acoustical signal deblurring
Authors: Taroudaki Viktoria , Taroudakis Michael , Smaragdakis Costas
Published: October 2018

Acoustical signals in applications of acoustical oceanography, such as ocean acoustic tomography and sea-bed classification using acoustic signals emitted from known sources, are optimally exploited if they are noise free. The effect of blur in acoustic signals has not been well studied, although the blurring mechanism might introduce severe problems in the use of the acoustic signals for specific applications, especially those using the full signal as the carrier of the relevant information. Deblurring of the signals in addition to denoising is therefore essential for the effective use of the signals. In our work, we apply a Statistical Optimal Filtering method that uses the singular value decomposition of a first estimate of the blurring matrix and statistics to deblur the signal in an efficient and effective way and to quantify uncertainty for the recovered signal. In this talk, we will present the method and discuss its effectiveness using as test case, an application of sea-bed classification based on a statistical characterization of an acoustic signal. The statistical characterization is particularly sensitive to noise and blur contamination of the exploitable signal and any attempt for getting a signal clear from noise and blur is absolutely necessary, for obtaining reliable results.
Recent acoustic designs in China, challenges, and design approach
Authors: Scelo Thomas , Fearnside Peter , Exton Peter
Published: October 2018

Marshall Day Acoustics has now completed and commissioned sixteen performing arts venues in China and has another sixteen in design or in construction. It seems an opportune time to reflect on the latest challenges, technically or otherwise and how we have successfully approached them. Projects have become bigger and more complex, yet clients’ expectations and requirement for certainty in the outcome have increased. The paper will include three recent examples. The 1,500-seat concert hall and 1,000-seat drama theatre of the Jiangsu Grand Theatre both required on-site design to ensure acoustic requirements were met, in time. The 2,000-seat Qingdao Grand Theatre achieved a very low reverberation time suitable for the use of multiple complex sound systems while maintaining the hard finish look desired by the client. This required both careful predictions and laboratory testing. Finally, the 2,040-seat opera house at Shaanxi Grand Theatre that was delivered in less than three years. Atypical materials and simple design principles were implemented to meet the project timeframe. These cases are examples of successful acoustic engineering and what can be achieved when applying first principles and sound science, backed by simulations, testing and experience.
Using passive acoustics to localize vocalizing oyster toadfish (Opsanus tau)
Authors: Putland Rosalyn , Mackiewicz Alayna , Mensinger Allen F.
Published: October 2018

Identifying where fish inhabit is a fundamentally important topic in ecology and acoustic tools can help management to prioritize acoustically sensitive times and areas. In this study, passive acoustic monitoring is presented as a viable tool for monitoring the positions of vocalizing fish species, like the oyster toadfish. Time of arrival differences (TOADs) of sound recordings on a four-hydrophone array were used to pinpoint the location of male oyster toadfish, Opsanus tau, a sedentary fish that produces boatwhistle vocalizations to attract females. Coupling the TOAD method with cross correlation of the different boatwhistles, individual toadfish were mapped during three-hour periods at dawn, midday, dusk, and midnight to examine the relationship between temporal and spatial trends. Seven individual males were identified within 24.2 m of the hydrophone array and up to 18.2 m of the other individuals. The advantages and disadvantages of using the TOAD method to localize individual fish will be discussed. Additionally, preliminary data on how individual toadfish respond to the anthropogenic sound of passing motorized vessels as well as conspecific boatwhistles will be introduced.
Buzzing sounds used as a mean of intra-specific interaction during agonistic encounters in male European lobsters (Homarus gammarus)?
Authors: Jézéquel Youenn , Bonnel Julien , Coston-Guarini Jennifer , Guarini Jean-Marc , Chauvaud Laurent
Published: October 2018

Passive acoustics is a useful non-invasive tool to collect behavioral information in marine species. This is the case for temperate crustaceans which are known to emit a large variety of sounds through diverse mechanisms. But despite numerous studies in tanks, little is known about their ecological meaning, particularly for decapods of high commercial interest. When stressed by handling, the European lobster (Homarus gammarus) vibrates its carapace and produces low frequency “buzzing sounds” that can be characterized in tanks. In this presentation, we discuss a straightforward experimental approach to investigating the role of these buzzing sounds in male European lobsters by combining passive acoustics and behavioral analysis (video and accelerometry). We recorded sound and video simultaneously during agonistic encounters. Based on the video, an ethogram was created with a total of 30 behaviors regrouped by agonistic levels. During agonistic encounters, European lobsters emitted buzzing sounds in association with stressful events such as claw grasping or tail flipping. Our results suggest that these sounds may be used by H. gammarus to maintain dominance around its shelter.