bluuebunny/crossref_metadata_2025 huggingface dataset:
Can Public Meetings Accurately Reflect Public Attitudes Toward Wildlife Management?
Authors: PETERSON CHRISTINE C. , MESSMER TERRY A.
Published: October 2011

Abstract: State wildlife agencies often use input obtained through public meetings to develop management policies. Because public meetings can be dominated by single stakeholder groups, these policies may not reflect the attitudes of new wildlife stakeholders. In 2000 the Utah Wildlife Board, after a series of public meetings, adopted a statewide policy for winter‐feeding mule deer (Odocoileus hemionus). The policy was implemented by the Utah Division of Wildlife Resources from 2001 to 2007 in Cache County of northern Utah, USA. In 2007, we surveyed Utah households representing metropolitan, nonmetropolitan, and Cache County residents (n = 1,800) to evaluate whether the winter‐feeding policy reflected the attitudes of all wildlife stakeholders. Survey respondents, regardless of residence strata, believed winterfeeding programs were essential for managing mule deer in Utah (χ26 = 7.02, P = 0.32). However, most respondents were reluctant to support feeding programs at the expense of habitat restoration projects (χ26 = 11.64, P = 0.07). Our results suggest that the winter‐feeding policy represented the attitudes of the Utah residents surveyed, though few had participated in its development. Respondents' strong utilitarian attitudes toward wildlife (e.g., strong support for hunting and feeding) influenced those respondents' perceptions of the policy. Given the effects of increased urbanization on utilitarian attitudes toward wildlife in many parts of the United States, coupled with decreasing numbers of traditional wildlife stakeholders, state wildlife agencies should continually reevaluate their public involvement processes to ensure new wildlife stakeholders' attitudes and concerns are represented.
Total Counts Versus Line Transects for Estimating Abundance of Small Gopher Tortoise Populations
Authors: STOBER JONATHAN M. , SMITH LORA L.
Published: October 2011

Abstract:Status and trends of gopher tortoise (Gopherus polyphemus) populations are a critical information need for natural resource managers, researchers, and policy makers. Many tortoise populations are small and isolated, which can present challenges for deriving population estimates. Our objective was to compare abundance and density estimates for a small tortoise population derived using a total burrow count versus estimates obtained with line transect distance sampling (LTDS) using repeated surveys. We also compared results of the 2 survey methods using standard burrow‐to‐tortoise correction factors versus assessing occupancy of all burrows with a camera scope. In addition, we compared LTDS data obtained using a compass and measuring tape to define transects to those obtained using a Global Positioning System (GPS) and Personal Data Assistant (PDA) field computer to navigate transects. Line transect distance sampling with repeated surveys (both with a measuring tape and compass and with a GPS—PDA) yielded sufficient observations of tortoises to calculate population estimates. From 18% to 31% of burrows were occupied by tortoises as determined with the burrow camera. We found 25 burrows during the LTDS survey that we did not find in the total count survey, which demonstrated that the assumption of 100% detection for the total count was not met; hence, density or abundance measurements derived with this method were underestimates. We recommend using GPS—PDA technology, scoping all burrows detected, and using LTDS with repeated surveys to estimate abundance and density for small gopher tortoise populations.
How to engage experienced medicine users at the counter for a pharmacy-based asthma inhaler service
Authors: Kaae Susanne , Nørgaard Lotte Stig
Published: October 2011

Objectives

Recent studies have identified recruitment of customers at the pharmacy counter as a limiter to successful provision of cognitive services in community pharmacies especially that of experienced customers with refill prescriptions. The aim of the paper is to gain insight into current problems of recruiting.

Methods

A qualitative study was conducted based on semi-structured interviews with 12 participants in a project in 2010 aimed at optimising recruitment of experienced asthma patients for the Inhaler Technique Assessment Service in Denmark. An ad hoc analysis was applied in order to interpret pharmacy staff perceptions of experienced asthma patients in comparison with newly diagnosed patients and to categorise the types of developed recruitment strategies as to whether they reflected a technical or everyday-life perspective on medicine.

Key findings

Effective recruitment processes were found to follow a generic pattern which consisted of a special type of opening question followed by providing a justification for the service. The participants perceived that the main difference between experienced and newly diagnosed patients was their degree of knowledge about their condition or correct inhaler technique. Most questions, and especially those related to reasons for motivating the customer to accept the service, were dominated by a professional technical understanding of medicine. In particular, follow-up justification based on a life-world perspective needs to be developed further. The identified type of communication might prevent some customers from accepting the service as they are not motivated by technical arguments but rather by how their daily symptoms can be relieved.

Conclusions

Pharmacy staff should focus both on adequate opening questions as well follow-up justification when trying to recruit customers for cognitive services. The study might inform future studies on how to create new and more adequate strategies for recruitment of customers for relevant cognitive services in community pharmacies.
Evaluation of a multi staged professional development course for practising pharmacists in anticoagulation management
Authors: Bungard Tammy J , Schindel Theresa J , Garg Sipi , Brocklebank Cynthia
Published: October 2011

Background

With the evolution of pharmacist prescriptive authority in Alberta, Canada, professional development courses need to impact change in daily practice. We designed a multi stage course targeting anticoagulation management with several components: (1) a print-based course to develop foundational knowledge; (2) a 2-day workshop; (3) a 3-day experiential programme; (4) distance mentorship to practice site; and (5) two full-day mentorship meetings.

Objective

To assess the impact of a comprehensive anticoagulation professional development course on practising pharmacists' knowledge, confidence and daily practice, with documentation of resources for the mentorship phases.

Methods

A mixed method of evaluation using surveys to assess pharmacist knowledge and confidence and semi-structured interviews to assess the impact on practice. Surveys were conducted prior to and following the workshop, after the experiential training and 4–6 months following completion of the workshop. Interviews were conducted following the experiential training and 4–6 months after the workshop.

Results

Enrolment for the complete multi stage course was limited to 12 pharmacists, while another 59 completed the course to the end of the workshop. Pharmacists completing the entire course had improved knowledge scores following the workshop, and between the workshop and 3-day experiential. These scores declined at 4–6 months. Improvements in confidence occurred throughout the course. At the final interview, all pharmacists indicated a positive impact on their practice. Mentorship was feasible and imperative to offer security to facilitate practice change.

Conclusions

Overall, this comprehensive multi stage course improved knowledge, confidence and practice for pharmacists.
Assessment of Fatigue Damage of Floating Fish Cages Due to Wave Induced Response
Authors: Thomassen Paul E. , Leira Bernt J.
Published: October 2011

Floating fish cages provide the main production utilities for salmon farming. However, despite their pivotal role in production safety as well as in protection of the environment, there is still much room for improvement in relation to verified structural design procedures and computerized tools for structural analysis. To a large extent, they can be regarded as not being in accordance with the state-of-the-art of structural analysis and design for more traditional types of marine structures. In this paper, a study of fatigue design for floating fish farms is presented. This study is based on a structure that is being applied by the Norwegian fish farming industry today. The floater is made of steel cylinders that are configured as a square. The formulation for the wave loading is based on a combination of potential theory and horizontal drag forces on the floater. Horizontal and vertical drag forces on the netpen are also accounted for. A fatigue design procedure for floating fish farms in steel is suggested. The procedure is based on a time domain analysis of the structure in irregular waves. For each seastate, 1/2 h (real time) analysis is performed and the stress history for an assumed critical location is computed. Based on the stress histories, the fatigue damage is estimated by application of rain flow counting and a given SN curve. The scatter diagram for the seastates at a given location is generated from the associated wind speed distribution.
Sound absorption of different green roof systems
Authors: Pittaluga Ilaria , Schenone Corrado , Borelli Davide
Published: October 2011

Experimental data on acoustical performances, in particular on sound absorption, of several green roof systems were evaluated and discussed. Measurements were performed on samples of three green roof systems, different for maintenance, plant setting and containment criteria, and categorized in extensive green roof (sample A), semi-intensive green roof (sample B), and common soil (sample C). Experimental values of normal incidence acoustic absorption coefficient and acoustic impedance were evaluated for each sample in one-third octave frequency bands from 160 to 1600 Hz by using a standing wave tube. Then, diffusive sound absorption coefficients and normal and diffusive weighted sound absorption coefficients were calculated in the same frequency range. Results show that green roofs provide high sound absorption, mostly if compared with the typical performances of traditional flat roofs. Curves of sound absorption coefficients result strongly dependent on the stratigraphy. Comparison between the different systems performed on the base of weighted sound absorption coefficients shows a better behavior for the sample B. Results obtained suggest that green roof technology, in addition to energy and environmental benefits, can contribute to noise control in urban areas by means of high sound absorption performances in relation to the size of the surface area.
Architectural acoustic elements to reduce the decay time in a room
Authors: Schnitta Bonnie , Russo Melissa , Greenwald Greg , Cain Michael
Published: October 2011

The paradise architectural acoustic devices are sound modifying architectural elements, or structures. The architectural structure can be made to look like any one of the standard architectural structures commonly used in a room, from baseboards to crown moldings or ceiling beams. Depending on the intended outcome, the architectural elements can either be a solid body, or what appears to be a solid element but has internal mathematically determined channels. This allows the architectural elements, or devices, to not only reduce or correct the decay time in the room, but also make certain that the architectural elements do not produce undesirable effects. The mathematical foundation of the various shapes and designs of the architectural acoustic structures, or elements, will be presented for a linear case. This will allow a better understanding of the underlining acoustical effects. An appreciation for a more precise mathematical description of the embodiments will also be discussed by additionally taking into account the nonlinear aspects of the various embodiments. Various views of an acoustic architectural device for reducing or correcting decay time will be presented. Additionally, the improvements to the acoustic environment of the room that result from the paradise architectural elements will be provided.
Acoustic simulation of renaissance Venetian churches
Authors: Boren Braxton B. , Longair Malcolm S.
Published: October 2011

The Venetian Renaissance was a confluence of innovative expression across many artistic disciplines. While architects like Palladio and Sansovino were designing architectural masterpieces in many of the churches built during this period, composers such as Willaert, the Gabrielli, and Monteverdi were composing complex polyphonic works for split-choir ensembles, exploring the tonal and spatial dimensions of musical performance. The large churches built during this period have extremely long reverberation times and provide low clarity for understanding the complex polyphony composed for these spaces. This paper uses modern acoustic simulation techniques to provide insights into the acoustics of large Venetian churches as they would have existed during the Renaissance. In consultation with architectural historians, the authors have collected data on the structure and layout of Palladio's Redentore and San Marco on festal occasions, when large crowds, extra seating, and wall tapestries would have provided extra absorption. Using Odeon, acoustic simulations predict that under festal conditions these churches would have had significant improvements in T30, EDT, and C80. The doge's position in San Marco's chancel has particularly good clarity for sources located in Sansovino's galleries, supporting historian Laura Moretti's hypothesis that these galleries were installed for the performance of split-choir music.
Impacts of classroom acoustics on elementary student achievement
Authors: Ronsse Lauren M. , Wang Lily M.
Published: October 2011

This research investigates relationships between unoccupied classroom acoustical conditions and elementary student achievement. Acoustical measurements were gathered in all of the third and fifth-grade school classrooms (67 total) in a public school district in north-eastern Nebraska, USA. Traditional classroom acoustic parameters, including background noise level and reverberation time, have been correlated to the standardized achievement test scores from students in the surveyed classrooms. Binaural impulse response measurements were also conducted in a subset of the rooms (20 total) and correlated to the student achievement scores. Acoustical metrics calculated from the binaural impulse response measurements include speech transmission index, distortion of frequency-smoothed magnitude, interaural cross-correlations, and interaural level differences. The results from this research indicate that scores on fifth-grade student language and reading subject areas are negatively correlated to higher unoccupied background noise levels. Also, the distortion of frequency-smoothed magnitude, which is a perception-based acoustics metric, was significantly related to the student language achievement test scores.
Comparison of the articulation test and speech transmission index values measured in two different acoustical poor conditions
Authors: Sommerhoff Jorge , Rosas Claudia
Published: October 2011

In this work, a comparison is made between articulation tests and speech transmission index (STI) values, measured in the same place, in two different acoustically poor room conditions, both with STI values of less than 0.4. In the first room condition, a 200 m3 reverberation chamber with background noise of less than 32 dBA was used. In the second room condition, pink noise was added to a small room with reverberation time of less than 0.6 s, till values of STI lower than 0.4 were reached. The articulation test corpus consisted in a 1000 phonetically Spanish combination of a consonant, vowel, and consonant (CVC logatoms). The logatoms were recorded in an anechoic chamber. In the articulation test and STI measurement, both signals were emitted in the rooms using a NTI Talkbox with a sound power equivalent to a normal human voice. The STI and articulation was measured at the listener's seats which were located at different distances from the source but within STI values less than 0.4. The articulation test results of both acoustical conditions are correlated separately with the measured STI. The results of the measurements indicate that for the same STI value, the subjective response statistically differs.
The effect of listener head movement on perceived envelopment and apparent source width
Authors: Parks Anthony J.
Published: October 2011

Current research examining listeners' perceived spatial impression of a concert hall relies on a fixed-head worldview, since the overwhelming majority of listening tests conducted to determine subjective spaciousness [listener envelopment (LEV) and apparent source width (ASW)] has required listeners to keep their heads fixed. Such a worldview is an incomplete one, because listeners make noticeable exploratory head movements while evaluating sonic environments, including the more common task of source localization as well as the more involved task of evaluating the spaciousness of a concert hall. This study investigates the role of listener head movement in the evaluation of perceived LEV and ASW under 15 different concert hall conditions simulated over eight loudspeakers using Virtual Microphone Control. The conditions consist of both varying ratios of front-to-back energy and varying levels of cross-correlated reverberant energy. Head movements are monitored in terms of angular rotation (azimuth, elevation, and roll) using a head tracker while listeners are prompted to give subjective ratings of LEV and ASW ranging from 1 (least) to 7 (most). The listening tests are then repeated while subjects are asked to keep their heads fixed. The head movements are analyzed and results of the tests are compared.
Marine acoustic ecologies and acoustic habitats: Concepts, metrics, and realities
Authors: Clark Christopher W. , Rice Aaron N. , Ponirakis Dimitri W. , Dugan Peter J.
Published: October 2011

Whales, dolphins, and porpoises (cetaceans) are adapted to produce and perceive sounds that collectively span 4–6 orders of magnitude along space, time, and frequency dimensions. Two important concepts, acoustic ecology and acoustic habitat, emerge from this perspective: where acoustic ecology is the study of acoustics involved in interactions of living organisms, and acoustic habitat as ecological space acoustically utilized by particular species. Cetaceans are dependent on access to their normal acoustic habitats for basic life functions. Communication masking from anthropogenic sounds that are chronically present can result in measurable losses of cetacean acoustic habitats, especially for low-frequency specialists, baleen whales. A communication masking model, informed by multi-year datasets, demonstrates cumulative influences of multiple vessels on fin, humpback and right whale acoustic habitats at spatial, temporal, and spectral scales matched to ecologically meaningful habitats. Results quantify acoustic habitat spatio-temporal variability over ecologically meaningful scales. In some habitats with high vessel traffic and vessel noise, predicted habitat loss and area over which animals can communicate is dramatically reduced compared to what it would be under non-vessel conditions. From a large-scale, ecological perspective, these acoustic habitat reductions likely represent significant costs for species for which acoustic communication is biologically critical.
Influence of impulsive sources on the soundscape of under-ice Arctic marine mammals
Authors: Arvelo Juan I.
Published: October 2011

The Arctic Ocean exemplifies the danger in using sound propagation and interaction models without a clear understanding of the physics of the problem or weaknesses inherent in these models. The zone-of-influence for under-ice marine mammals should be expected to differ significantly from that of open-sea organisms. However, increasing the effective sound attenuation, to empirically account for sound interactions with keel drafts, may lead to grossly erroneous conclusions from predictive and forensic studies. Ice elasticity and ridges combine to increase water/ice low-frequency sound penetration enabling long-distance transmission along this liquid–solid interface in the form of an evanescent wave. Consequently, sound pressure and exposure levels near the canopy are significantly higher even when the acoustic wavelength is several times longer than the ice thickness. Therefore, these physical mechanisms should also be taken into account in Arctic environmental impact assessment calculations. For example, it is more efficient for under-ice marine mammals to mitigate exposure to subsequent active sonar events by diving just a few meters deeper under the ice cap rather than increasing range by hundreds of meters. Therefore, some under-ice marine mammals are likely to exhibit a stronger preference toward diving avoidance behavior. [Work funded by UAF sub-award under NOAA Grant NA09NOS4000262.]
The acoustic ecology of minke whales in the tropical north pacific
Authors: Norris Thomas , Martin Steven W. , Yack Tina M. , Thomas Len , Oswald Julie
Published: October 2011

The minke whale (Balaenoptera acutorostrata) is a ubiquitous but rarely sighted species that occurs in subtropical waters of the North Pacific during winter and spring. It produces a unique vocalization called a boing that is easy to detect and localize. We characterized the acoustic ecology of minke whales by detecting and localizing boings using passive acoustic methods. We conducted passive acoustic line-transect surveys in 2006 for a large area around the Northern Mariana Islands (site 1), and in 2010 for a smaller area off the Pacific Missile Range, Kauai, HI (site 2). We also recorded acoustic data from deep waters using cabled seafloor hydrophones at site 2. Densities of calling animals were estimated from line-transect surveys and will be used to estimate calling rates for use in spatially explicit capture–recapture analysis of fixed seafloor hydrophone data. Spatial analysis of acoustic localizations in relation to bathygraphic and oceanographic variables will be discussed. We provide examples of counter-calling and complex responses to vessel noise. These results provide important information about the acoustic ecology and behavior of minke whales that can be used to improve the conservation and management of this elusive but common whale. [Work sponsored by ONR and NAVFAC.]
High-frequency modulated signals of killer whales (Orcinus orca) in the North Pacific
Authors: Simonis Anne E. , Baumann-Pickering Simone , Oleson Erin , Melcón Mariana L. , Gassmann Martin , Wiggins Sean M. , Hildebrand John A.
Published: October 2011

Killer whales (Orcinus orca) use acoustic signals to echolocate and communicate, although there are differences in acoustic behavior among ecotypes. Atlantic resident populations recently have been reported to produce acoustic signals at higher frequencies than previously known. Acoustic recordings from ship-based acoustic and visual surveys and from autonomous acoustic recorders reveal that killer whales across a broad range of the North Pacific Ocean also use similar high frequency modulated signals. The median peak frequency of these signals ranged from 19.6 to 36.1 kHz at different locations, with median durations from each location ranging from 50 to 163 ms. All observed high frequency modulated signals were frequency downswept with no or few inflection points. Killer whales are generally believed to use whistles for close range communication in social contexts; however, these uniform, repetitive, down-swept signals are similar to bat echolocation signals and may have echolocation functionality. The large geographic range of occurrence suggests that these signals are utilized by different killer whale ecotypes. [Work funded by Michael Weise at the Office of Naval Research, Frank Stone at Navy CNO-N45, Bob Haskell at Pacific Life, and Mark Spaulding at the Ocean Foundation.]
Long-term passive acoustic monitoring of parrotfishes (Scaridae) in the Hawaiian Archipelago
Authors: Munger Lisa M. , Fisher-Pool Pollyanna , McCoy Kaylyn , Lammers Marc O. , Tricas Timothy , Au Whitlow W. L. , Wong Kevin , Brainard Russell E.
Published: October 2011

Parrotfishes (family Scaridae) are an important component of coral reef ecosystems, and this key functional group plays a major role in algae removal and bioerosion of reef substrate. They are also heavily fished in many locations, which may lead to ecosystem-wide impacts such as increased algal cover. In the State of Hawaii, parrotfish management is a priority for marine resource managers, with an ongoing need for accurate population monitoring that is currently addressed by diver-based visual surveys. However, parrotfishes are highly mobile and somewhat skittish around SCUBA divers, particularly in areas where fishing pressure is high. Because parrotfishes produce frequent audible scraping and crunching sounds associated with feeding, passive acoustic monitoring (PAM) can provide information on parrotfish occurrence without requiring the invasive presence of divers. Here, we present results from analyses of parrotfish foraging sounds in long-term acoustic recordings from 10 shallow reef locations throughout the Hawaiian Archipelago dating back to 2006. Parrotfish sounds are compared spatially across a fishing pressure gradient, from heavily fished areas in the main Hawaiian Islands to protected waters within the Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands). Results from PAM are compared when possible with data from adjacent visual censuses conducted by divers.
Van Holliday: Ocean acoustician and biological oceanographer
Authors: Pieper Richard E.
Published: October 2011

I first met Van Holliday in 1970 at the International Symposium on Biological Sound Scattering in the Ocean. We were both graduate students, Van at Scripps and I was at the UBC. Two of us were interested in higher frequency acoustics and scattering from zooplankton. In the Working Group on Bioacoustics Recommendations, Brooke Farquhar and Van Holliday wrote “By using acoustic techniques over large frequency ranges (100 Hz to 10 mHz), the distribution of nekton and plankton could be obtained.” I moved to USC after graduation and began to meet Van at ONR site reviews. We received funding from ONR and NSF in mid 1970. I bought a plankton pump and Van put together a four-frequency acoustic array (0.5, 1.16, 1.80, and 3.08 MHz). The program began and continued for over 30 yr. With the success of our four-frequency system, we obtained a recently de-classified Shadowgraph system from the Navy and Van built a 21-frequency array (100 kHz to 10 MHz) which was used in many ocean environments. The uniqueness of scattering from zooplankton led Van to develop an inversion algorithm to calculate zooplankton size spectra from the acoustic data. The four-frequency TAPS was designed and is used by many today.
Van Holliday: A lifetime of contributions to acoustical oceanography
Authors: Farmer David M.
Published: October 2011

Van Holliday's achievements have transformed the acoustical study of marine biology. Working closely with colleagues from fisheries and marine biology, he brought his keen understanding of acoustics and lively curiosity to the solution of many challenging problems. In reviewing his accomplishments one is struck by their range and by the special way in which he reached out to the fields to which he contributed. For example, when he solved a problem such as acoustical scattering by fish schools, he quickly saw the possibilities of exploiting his new understanding to study schooling behavior. He explored the characteristics of ice noise, he was the first to track the movement of whales acoustically and he made major contributions to our understanding of the scattering of sound by zooplankton. His work on plankton acoustics led to the important new sub-discipline of spectral acoustic determination of zooplankton populations and their behavior. His profound contributions to biology, biophysics, and other marine topics display an intellectual breadth, an enthusiasm for crossing disciplinary boundaries, and a deep curiosity that serve us well as a model for achievement in the field of acoustical oceanography.
Planktonic layers: New insights stimulated by Van Holliday
Authors: Cowles Timothy J. , Benoit-Bird Kelly
Published: October 2011

During the late 1980s and early 1990s, initial evidence for persistent thin layers of phytoplankton (less than 1 m in thickness) in the upper ocean was obtained with optical instrumentation. These observations were inconsistent with the existing understanding of small-scale vertical mixing processes and raised questions about the ecological consequences of such structures, should they prove to occur on a regular basis. Dr. D. Van Holliday quickly saw the need for new approaches in acoustical oceanography to address these important ecological questions. Over a period of a few years, Dr. Holliday developed new acoustical tools that could be deployed in concert with other sensors. His moorings with customized high-frequency transducers allowed acoustical resolution over scales of centimeters, sufficient to capture the acoustic signature of marine zooplankton and their spatial relationship to their food supply. The insights provided by Van's work, and his constant encouragement to his colleagues, have led to significant breakthroughs in our understanding of upper ocean physical, biological and chemical processes. This presentation will incorporate recent observations and build upon Van's observations to illustrate the importance of his contributions to ocean science.
Multifunctional acoustic metamaterial composites
Authors: Naify Christina J , Nutt Steven
Published: October 2011

Composite structures used in aerospace applications are designed to optimize high bending stiffness to weight ratio. Acoustical performance of composite structures, however, is notoriously poor due to decreased mass law performance and decreased coincidence frequency. Efforts to improve the acoustic properties of composite structures have included optimization of material selection as well as addition of acoustic treatments. Additionally, development of composite structures to include multifunctional properties has increased. In this study, two types of multifunctional approaches were examined using acoustic metamaterials. Locally resonant acoustic metamaterials (LRAM), which have sound insulation performance of 500% increase over the mass law prediction, were integrated into a high-strength sandwich structure array to provide increased acoustic performance without increase in mass. LRAM were constructed of thin, tensioned membranes with centrally located masses in the form of small magnets. Varying the geometry of the metamaterial to tune effective frequencies optimized acoustic performance. Acoustic excitation of the central magnet was used to harvest energy by positioning a wire coil around each cell such that the displacement of the magnet induced a voltage. Combination of energy harvesting and array configurations produced multifunctional materials with three applications: increased stiffness, optimal acoustic performance, and harvesting of acoustic energy.
Transmission loss of curved sandwich-composite panels with attached noise control materials
Authors: Atalla Noureddine , Sgard Franck
Published: October 2011

This paper discusses the modeling of the transmission loss of curved sandwich-composite panels with attached noise control treatments using both analytical and numerical methods. Special attention is devoted to the modeling using the Transfer Matrix Method (TMM) and Statistical Energy Analysis (SEA) of these structures in various mounting conditions (single wall and double wall) under diffuse acoustic field excitation with a systematic comparison with an efficient FEM/VBEM formulation of the problem. Classically, in SEA models the sound package is unwrapped and the TMM is used to calculate its effects in terms of added damping, absorption, and insertion loss. Examples are presented to examine the validity of this practice and demonstrate its range of applicability and usefulness.
Active control of a composite panel utilizing piezoelectric patches connected to negative capacitance shunts
Authors: Cunefare Kenneth A. , Beck Benjamin S. , Badea Romero Francisco Mariano
Published: October 2011

Many industries are implementing the use of thin, lightweight carbon fiber panels to increase stiffness and decrease weight. Yet, vibrations of the panels can reach large amplitudes causing an increased acoustic noise field. The use of piezoelectric actuators bonded on or within the composite panels can be used to decrease the vibration. Negative capacitance shunts have been shown to decrease flexural vibrations over a broadband frequency range. By using the negative capacitance shunts connected to piezoelectric patches, the noise field can be reduced. Yet, the effect of the control may also cause increased acoustic coupling causing more of the flexural modes to create propagating acoustic waves. The acoustic effects of the control system on a clamped carbon fiber composite panel are analyzed by investigating the flexural amplitude and wave number decomposition. The results of the numerical model of the panel are experimentally validated.
Using the Markov chain Monte Carlo method to estimate model order
Authors: Goggans Paul M. , Chan Chung-Yong
Published: October 2011

Markov chain Monte Carlo (MCMC) methods are widely used in the solution of parameter estimation problems arising in acoustics and other applications. The use of MCMC to estimate the parameters of a single model is well established. However, in many applications, there is not a single model for the data but rather a number of competing models. A common method of dealing with multiple models is to use MCMC to compute the posterior probability and estimate the parameter values of each model in turn. However, for problems with many models, it is more efficient to combine the parameter spaces of all models into a single space and use MCMC to perform across-model sampling of the joint space. Although the development of an MCMC algorithm of this sort is sufficiently difficult so as to be unprofitable for the non-specialist, the acoustician wishing to solve their multi model parameter estimation problem using MCMC can still do so using an existing algorithm. This presentation gives an overview and brief tutorial of MCMC for parameter estimation and then discusses and gives an example of using the open source computer program BayeSys [Skilling, 2004] to determine the model order of a simple atomic model.
Bayesian inversion of seabed reverberation and scattering data via parallel tempering
Authors: Dosso Stan E. , Holland Charles W.
Published: October 2011

This paper describes Bayesian inversion of reverberation data for seabed scattering and geoacoustic parameters using the method of parallel tempering. The seabed is modeled as a sediment layer over a semi-infinite basement, with interface scattering occurring at the rough upper and lower boundaries of the sediment and volume scattering within the layer. The scattering mechanisms are considered to be independent and are modeled using perturbation theory and the Born approximation. Unknown parameters include seabed geoacoustic properties (sediment thickness and sound speeds, densities, and attenuations for the sediment and basement) and scattering properties (roughnesses and scattering strengths for upper and lower layer boundaries and volume scattering strength for the sediments). The reverberation inversion problem is found to be strongly nonlinear with a highly multi-modal posterior probability density (PPD). Standard Markov-chain Monte Carlo (MCMC) methods, such as Metropolis–Hastings sampling, are ineffective at sampling the complicated parameter space. However, parallel tempering, which runs multiple MCMC chains at a series of increasing temperatures with probabilistic transitions between chains, effectively samples the multi-modal PPD. Methods to increase efficiency using multiple parallel chains at each temperature and exploiting improved mixing with temperature are considered.
Sequential Bayesian filtering for seismic tremor location
Authors: Yardim Caglar , Gerstoft Peter , Hodgkiss William S. , Michalopoulou Eliza
Published: October 2011

Sequential filtering provides a suitable framework for estimating and updating the unknown parameters of a system as data become available. The foundations of sequential Bayesian filtering with emphasis on practical issues are first reviewed focusing on particle filtering and particle smoothing. Filtering is demonstrated to be a powerful estimation tool, employing prediction from previous estimates and updates stemming from physical and statistical models that relate seismic measurements to the unknown parameters. Particle filtering and particle smoothing are discussed for tracking multiple tremor locations.
Acoustic scattering from a metallic pipe: Mode isolation and visualization via finite element analysis
Authors: España Aubrey L. , Williams Kevin L. , Marston Philip L. , Zampolli Mario
Published: October 2011

Understanding how sound couples to, and radiates from targets, aids in finding frequencies and angles advantageous for target detection and classification. Finite element models, coupled with physical acoustics models, have been used to identify resonant modes of truncated, solid cylinders [D. B. Thiessen et al., J. Acoust. Soc. Am. 129, 2686 (2011)]. This technique is extended here to an aluminum pipe. Scattering from the pipe in the freefield is studied with a finite element model based on the decomposition of the elastic displacements and fluid pressure in a series of azimuthal Fourier modes. To facilitate elastic mode identification, the calculations for the scattered pressure from a nearly rigid pipe of identical size are subtracted coherently from the elastic model results. Plotting these “subtracted” pressure amplitudes and particle displacements on the wet surface of the pipe allows for visualization of the elastic modes. Subsequently, the model is extended for the pipe in contact with sand, via a superposition of freefield results along with the water/sand reflection coefficient. The method is used to study the modal scattering in the presence of the interface. Where applicable, finite element results are validated by predictions from ray theory and experimental results. [Work supported by ONR.]
Case study: Active acoustics at the Barbara Streisand scoring stage
Authors: Ellison Steve , Murphy Shawn , Schwind David R.
Published: October 2011

Scoring stages are recording studios large enough to accommodate an orchestra, and typically used to record music sound tracks for films. The acoustic properties and goals of scoring stages are reviewed, and compared with other venue types. Recently, an active acoustics system was installed in the Barbara Streisand scoring stage on the Sony lot in Culver City, California. The system was used to electronically vary the reflected sound and reverberation during the recording of several film scores. The objectives, design, and performance of the system in the room is reviewed. The range of settings and controls provided to the scoring mixer are described as well as the process used to select parameters for different aspects of the score. These had implications on the artist performance as well as the recording and mixing process. The resultant reverberation times achieved are compared with archetypical orchestral performance venues as well as other scoring stages.
Extending the acoustical versatility of large performing arts classrooms
Authors: Brenneman Robert M. , Conant David A.
Published: October 2011

To accommodate an extensive array of performing arts programs with limited financial and facility resources, learning institutions often desire a high-degree of acoustical versatility within their larger classroom performance spaces. For the acoustician, achieving quality room acoustics in a singular space suitable for lecture, performance, and application of performance technologies can pose a significant challenge. The large multi-purpose performing arts classroom at Mesa Community College's Red Mountain Campus demonstrates how careful selection of sound absorptive materials, shaping of sound reflective surfaces, material placement, and employment of variable acoustics methods including novel, custom gobos can provide a diverse acoustical environment for addressing the varying acoustical needs of dance, music, and theater departments. This paper presents the cost-effective and practical materials and methods utilized within this multi-purpose performing arts classroom for its use as a teaching, drama, dance, and music performance space for virtually all music genres, from jazz to renaissance choral works.
Cost-effective evaluation of different residential hard-surfaced flooring and underlayment systems
Authors: Hale Marlund E.
Published: October 2011

There is increasing interest in replacing carpeted flooring with hard-surfaced flooring. Changing from soft-surfaced to hard-surfaced floors always results in an increase in the liveness of hard-flooring rooms and increased impact noise in lower rooms due to reduced impact isolation performance of the revised floor/ceiling assembly. An effective underlayment between the subfloor and the hard-surfaced flooring must be carefully selected and evaluated for ultimate compliance with floor/ceiling assembly performance requirements. In addition, any overall increase in flooring thickness is a major concern. This paper presents optimized field performance testing of several condominiums in a luxury multi-family residential complex for which the homeowner's association had set strict performance and testing requirements. Failure meant restoring the flooring to its original condition. A series of in situ and special field tests were undertaken to assist in the selection of qualifying underlayment systems for the desired hard-surfaced flooring. In situ, client-preferred, flooring samples were installed by the respective flooring contractors. Special field tests that involved the preferred systems and other flooring/underlayment combinations were conducted in a vacant two-story residence. In the in situ and vacant testing locations, the respective variables at each location were the different flooring and multiple underlayment systems.
The potential of bioacoustic absorption spectroscopy for long term monitoring of fish populations in the ocean
Authors: Diachok Orest
Published: October 2011

Bioacoustic absorption spectroscopy (BAS), which exploits frequency selective attenuation due to swim bladder resonances, could be incorporated into ocean observatories for long term monitoring of fish populations. BAS measurements employ environmentally friendly source levels (170 dB) and provide unbiased (by avoidance and proximity to boundaries) estimates of number densities versus fish length (and with ancillary information, species). The BAS II experiment, which was conducted in the Santa Barbara Channel, and employed a fixed ultra-broadband (0.3–10 kHz) source and a fixed vertical hydrophone array separated by 4 km, demonstrated the power of this method. Observed absorption lines in frequency/depth space were consistent with theoretically calculated resonance frequencies of directly sampled year classes of sardines and anchovies, OConnell's (1955) measurements of the dimensions of the swim bladders of these species, and echo sounder measurements of layer depths. Strategies for incorporating BAS measurements into existing fish monitoring methods will be addressed. [This research was supported by the Office of Naval Research.]
Application of chirp technology in earth science: From sediment dispersal to acoustic trenching of faults
Authors: Driscoll Neal , Kent Graham
Published: October 2011

CHIRP technology developed and perfected by Steve Schock and others allows scientists to image the earth at the scale processes shape it. Here, we present CHIRP images from a number of different tectonic and depositional settings. One example is from the Salton Sea, where we discovered faults near the southern end of the San Andreas Fault. Rupture on these newly discovered step-over faults has the potential to trigger large earthquakes on the southern San Andreas Fault (M7.5). Using the CHIRP technology to conduct “acoustic trenching” has revolutionized the study of paleoseismology and geohazards. Another example of CHIRP technology is from the continental shelf edge, offshore the US East Coast where large tensional cracks are observed (~4 km long and 1 km wide) and they might mark the location of the next slope failure along the margin. Even though rare, slope failure along the continental margin may lead to tsunami generation along the US East Coast. Sedimentary layers are the recorder of earth history and CHIRP technology allows us to image and decipher the origin of these layers in terms of climate change and tectonic deformation. The development of this technology is clearly one of the big advancements in subsurface geophysical imaging.
Can slowly varying sediment layers respond acoustically like a discrete target?
Authors: Holland Charles W. , Ellis Dale D.
Published: October 2011

One of the most challenging issues in active sonar is the discrimination of targets from clutter. In bottom-limited areas, one of the primary sources of clutter is from the seabed. An important source of seabed clutter is discrete objects that may lie on or under the sediment interface. It is clear that target-like scattered returns should arise from discrete features that have a spatial scale, or scattered response with time scales of order of the target of interest. The intent of this research is to show that in certain cases, slowly and continuously varying sediment layers can also lead to a target-like response. This is not an intuitive cause of clutter, and the physical mechanisms that lead to the target-like response are expounded.
Physics-based inversion of high-frequency multibeam sonar data
Authors: Jackson Darrell , Hefner Brian T.
Published: October 2011

This work follows a path begun by other investigators toward physics-based inversion of sonar data. Data were acquired as part of the GulfEx11 experiment using a Reson 7125 multibeam sonar mounted on a vessel in a four-point mooring. One important feature of this effort is the simultaneous acquisition of ground-truth on seafloor properties, including sound speed, attenuation, and roughness. In addition, several frequencies, spanning 150–450 kHz, were used. As typical of this approach, a model is used to generate echo intensity time series including scattering by both seafloor roughness and volume heterogeneity. The model parameters are adjusted to provide a match to data, yielding estimates of acoustic impedance, attenuation, volume scattering strength, and roughness spectral parameters. Volume scattering is treated using an empirical model, while roughness scattering is treated using the small-slope approximation. The narrow beamwidths of sonars of this type facilitate separation of the roughness and volume signals, but pose a challenge with regard to compensation for variations in pitch and roll. A compensation scheme will be discussed and inverted parameters will be compared to ground truth. [Work supported by ONR.]