bluuebunny/crossref_metadata_2025 huggingface dataset:
Adoption of Agri‐environmental Programmes in Swiss Crop Production  L’adoption des programmes agroenvironnementaux dans les grandes cultures suisses  Die Adoption von Agrarumweltprogrammen in der Schweizer Getreideproduktion
Authors: Finger Robert , Lehmann Bernard
Published: April 2012

summary

Adoption of Agri‐environmental Programmes in Swiss Crop Production

We analyse the adoption of agri‐environmental programmes, i.e. extensive and organic crop production, in Switzerland for the years 2008 and 2009. While extensive crop production is adopted by about 60 per cent of all eligible farms, the adoption of organic crop production is very limited. Using logistic regressions we find that farms located in adverse production conditions (e.g. at higher altitudes) are more likely to be adopters of extensive crop production. Moreover, our results show that the probability of adopting organic production decreases with increasing specialisation in crop production. We find that organic producers tend to be slightly younger and better educated than other farmers. However, no differences in farmers’ age and education are found between non‐adopters and extensive crop producers. This shows that, in general, the non‐adoption of agri‐environmental programmes in Switzerland is not primarily an educational problem. Moreover, we find that land tenure has no influence on the adoption of agri‐environmental crop production schemes. Thus, large shares of rented land do not limit the adoption of agri‐environmental programmes. In order to increase the adoption rates of extensive and organic production, particularly in non‐adverse production conditions, site‐ and region‐specific levels of ecological direct payments could be used.
Challenges in the Global Agri‐Food Sector: A Consultant’s Perspective on ‘Big Picture’ Issues  Les défis pour le secteur agroalimentaire mondial : le point de vue d’un consultant sur les grandes questions  Herausforderungen in der globalen Agrar‐ und Ernährungswirtschaft: Ansichten eines Unternehmensberaters mit Blick auf das große Ganze
Authors: Giles John
Published: April 2012

summary

Challenges in the Global Agri‐Food Sector:A Consultant’s Perspective on ‘Big Picture’ Issues

The UK and international agri‐food supply chain is going through an extraordinary period of change. The impact of the global economic recession and the ongoing growth of world population and incomes, especially in the emerging markets of the BRICs and N–11 countries, along with unusual climatic and production conditions have all combined to create the so‐called ‘perfect storm’. Many reports tell us why we have reached this situation; but fewer focus on what we need to do in order to meet the challenges and how the well informed, bold and brave companies might take advantage of the opportunities. For farmers, we have often given the advice of ‘farm a bit bigger, buy a bit sharper and sell a bit higher’. It sounds simple but I am not sure that the current situation changes this very much. For food companies our advice has often been, ‘find, get in and stay in an identified chain’. Again in this fast changing environment, being outside a recognised supply chain is a risky place to be. And there are a host of other factors to take into account. As consultants, our biggest challenge is providing advice on what to do, rather just explaining what has happened and why.
The Festivals Trial Protocol: A Randomized Evaluation of the Efficacy of Functional Strength Training on Enhancing Walking and Upper Limb Function Later Post Stroke
Authors: Mares Kathryn , Cross Jane , Clark Allan , Barton Garry R. , Poland Fiona , O'Driscoll Marie-Luce , Watson Martin J. , McGlashan Kate , Myint Phyo K. , Pomeroy Valerie M.
Published: April 2012

Rationale

Functional Strength Training may enhance motor function of people who are more than six months post stroke.

Aims

to evaluate the clinical efficacy of enhancing upper and lower limb motor function with FST to explore participants' views (expectations and experiences) of FST, and to determine what cost-effectiveness data to collect in a subsequent Phase III trial.

Design

Randomized, observer-blind trial with embedded qualitative investigation of participants' views of FST ( n = 6, purposive sampling).

Study

Participants ( n = 58), six months to five years after stroke with difficulty using their paretic upper (UL) and lower limbs (LL) for everyday functional activity. All will be randomized to either FST-UL or FST-LL delivered in their own homes for fours days each week for six weeks. FST involves repetitive progressive resisted exercise during goal directed functional activities. The therapist's main input is to provide verbal prompting and feedback.

Outcomes

Measures will be undertaken before randomization (baseline), after the six-week intervention (outcome) and six weeks thereafter (follow-up). Primary outcomes for clinical efficacy will be the Functional Ambulation Categories (FAC) and the Action Research Arm Test (ARAT). Clinical efficacy analysis will use the proportional odds model for FAC and a Mann-Whitney test for ARAT. Participants' views of FST will be explored at baseline and outcome through audio-taped, semi-structured, narrative approach, interviews. The analytic process for interviews will sort transcribed data thematically and seek categories to inform conceptualization (theory-building). A purpose-designed cost questionnaire will identify what cost resource items are likely to be affected by FST.
Regulatory mobilization and service delivery at the edge of the regulatory state
Authors: Chng Nai Rui
Published: April 2012

Where there is weak state capacity to carry out regulatory, redistributional, and developmental functions characterizing much of the developing world, the role of governance and service delivery is also performed by a myriad of private actors. Institutional reform in the utility sector in developing countries has often failed to distinguish between social and economic regulation. I show how private actors like NGOs and local community groups undertake what I term “regulatory mobilization” to influence the new rules of the service delivery game, as well as to deliver much‐needed basic services to urban poor communities. Based on extensive fieldwork carried out in the Philippines, this article reveals and explains the politics of the informal sector at the edge of the regulatory state. More than a decade since the privatization of the Metropolitan Waterworks and Sewerage System in Metro Manila in 1997, water access for the urban poor remained limited as privatized water utilities faced difficulties in extending service provision. In the context of an unpredictable regulatory landscape and an oligarchic patrimonial state, unexpected collective action by organized urban poor communities and NGOs has taken place around water as a subsistence right. Combining hybrid mobilizations to obtain water as well as influencing the rules governing their provision, these forms of regulatory mobilization appear to be peripheral and episodic. However, depending on how local and sectoral politics are conflated, such regulatory mobilization may sometimes not only result in obtaining subsistence goods, but may also occasionally project countervailing power in the policy sector, and influence formal regulatory frameworks in surprising ways.
Mindfulness Training and Teachers' Professional Development: An Emerging Area of Research and Practice
Authors: Roeser Robert W. , Skinner Ellen , Beers Jeffry , Jennings Patricia A.
Published: April 2012

This article focuses on how mindfulness training (MT) programs for teachers, by cultivating mindfulness and its application to stress management and the social‐emotional demands of teaching, represent emerging forms of teacher professional development (PD) aimed at improving teaching in public schools. MT is hypothesized to promote teachers' “habits of mind,” and thereby their occupational health, well‐being, and capacities to create and sustain both supportive relationships with students and classroom climates conducive to student engagement and learning. After defining mindfulness and its potential applications in teacher education and PD, this article discusses emerging MT programs for teachers, a logic model outlining potential MT program effects in educational settings, and directions for future research.
Predicting efficacy of dipeptidyl peptidase‐4 inhibitors in patients with type 2 diabetes: Association of glycated hemoglobin reduction with serum eicosapentaenoic acid and docosahexaenoic acid levels
Authors: Iwasaki Masahiro , Hoshian Fuminori , Tsuji Tomoko , Hirose Naoki , Matsumoto Tomoko , Kitatani Naomi , Sugawara Kenji , Usui Ryota , Kuwata Hitoshi , Sugizaki Kazu , Kitamoto Yuka , Fujiwara Shuichi , Watanabe Koin , Hyo Takanori , Kurose Takeshi , Seino Yutaka , Yabe Daisuke
Published: April 2012

This study was initiated to identify clinical and dietary parameters that predict efficacy of dipeptidyl peptidase‐4 inhibitors. A total of 72 untreated Japanese patients with type 2 diabetes who received DPP‐4 inhibitors (sitagliptin, alogliptin or vildagliptin) for 4 months were examined for changes of glycated hemoglobin (HbA1c) and body mass index (BMI), and self‐administered 3‐day food records, as well as serum levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). DPP‐4 inhibitors significantly reduced HbA1c (before initiation of DPP‐4 inhibitors 7.2 ± 0.7%, 4 months after initiation of DPP‐4 inhibitors 6.7 ± 0.6% [paired t‐test, P < 0.01 vs before]). Multiple regression analysis showed that changes of HbA1c were significantly correlated with baseline HbA1c, as well as estimated intake of fish. Furthermore, changes of HbA1c were significantly correlated with serum levels of EPA (r = −0.624, P < 0.01) and DHA (r = −0.577, P < 0.01). HbA1c reduction by DPP‐4 inhibitors is significantly correlated with estimated intake of fish and serum levels of EPA and DHA. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00214.x, 2012)
Associations between aggressive behaviour scores and cardiovascular risk factors in childhood
Authors: Louise S. , Warrington N. M. , McCaskie P. A. , Oddy W. H. , Zubrick S. R. , Hands B. , Mori T. A. , Briollais L. , Silburn S. , Palmer L. J. , Mattes E. , Beilin L. J.
Published: April 2012

Objective

To examine the influence of aggressive behaviour scores on cardiovascular disease (CVD) risk factors throughout childhood.

Methods

This study utilized cross‐sectional and longitudinal data from the Western Australian Pregnancy Cohort (Raine) Study (n = 2900). Aggressive behaviour scores were derived from the Child Behavior Checklist/4–18(CBCL), Youth Self‐Report/11–18 (YSR) and Teacher Report Form/6–18 (TRF). CVD risk factors included body mass index (BMI), blood pressure, fasting lipids and homeostasis model of insulin resistance (HOMA‐IR).

Results

Girls with higher aggressive behaviour scores had higher BMI from 10 years of age (P ≤ 0.001), higher BMI trajectories throughout childhood (P = 0.0003) and at 14 years higher HOMA‐IR (P = 0.008). At the 14‐year survey, this equated to a difference of 1.7 kg/m2 in the predicted BMI between the extreme CBCL scores in girls (top 5% (CBCL ≥ 17) vs. CBCL score = 0). Boys with higher aggressive behaviour scores had higher BMI at 5 years (P = 0.002), lower diastolic pressure at 14 years (P = 0.002) and lower systolic blood pressure trajectories throughout childhood (P = 0.016).

Conclusion

Aggressive behaviour influences BMI from early childhood in girls but not boys. If this association is causal, childhood offers the opportunity for early behavioural intervention for obesity prevention.
Effect of inserting a thin buffer layer on the efficiency in n-ZnO/p-Cu2O heterojunction solar cells
Authors: Nishi Yuki , Miyata Toshihiro , Minami Tadatsugu
Published: April 2012

Transparent conducting Al-doped ZnO (AZO)/nondoped ZnO/Cu2O heterojunction solar cells were fabricated by inserting a thin nondoped ZnO film as a buffer layer between an n+-AZO thin film and a p-Cu2O sheet prepared by thermally oxidizing a Cu sheet. The effect of inserting the buffer layer on the obtainable photovoltaic properties in n+-AZO/n-ZnO/p-Cu2O heterojunction solar cells was investigated to improve the conversion efficiency. An improvement of photovoltaic properties was obtained by optimizing the thickness as well as the deposition conditions in the nondoped ZnO thin-film buffer layer. The obtained improvement of photovoltaic properties may be attributable mainly to an increase of the barrier height formed in the np junction, resulting from the inserted buffer layer functioning as an n-type ZnO layer as well as an enhancement of carrier lifetimes near the interface between the nondoped ZnO thin-film buffer layer and the Cu2O. A high efficiency of 4.08% was obtained in an AZO/nondoped ZnO/Cu2O heterojunction solar cell fabricated using a buffer layer prepared at room temperature and an O2 gas pressure of 1.0 Pa with a thickness of 50 nm on a Cu2O sheet and measured under simulated AM1.5G solar.
Design and evaluation of a hybrid photoacoustic tomography and diffuse optical tomography system for breast cancer detection
Authors: Xi Lei , Li Xiaoqi , Yao Lei , Grobmyer Stephen , Jiang Huabei
Published: April 2012

Purpose

: The authors present the design and evaluation of a second‐generation (G2) hybrid photoacoustic tomography (PAT) and diffuse optical tomography (DOT) imaging system for detection of breast cancer. The combined PAT/DOT system takes full advantages of two different modalities to provide complementary information and most accurate recovery of tissue optical properties.

Methods

: This system was designed to produce cross‐section images of breast tissue with a ring‐shaped home‐made array of 64 wideband acoustic transducers combined with an array of 16/16 source/detector optical fiber bundles. A scanning light delivery system was built to illuminate a large area of breast tissue for optimized tissue penetration. Finite element reconstruction methods for quantitative PAT and DOT were utilized to recover absorption and scattering coefficients of tissue‐mimicking phantoms andex vivo tumor tissue.

Results

: Performances of the acoustic transducer array and the PAT/DOT system were investigated in detail. Frequency response of the transducers is from 380 kHz to 1.48 MHz and maximum frequency response is up to 2 MHz. Directivity of a single element in the array is ±30°. The PAT/DOT system offers a spatial resolution of ∼0.5 mm for PAT and of ∼4.0 mm for DOT. Quantitatively accurate absorption and scattering coefficients were obtained from both the phantom andex vivo experiments.

Conclusions

: The PAT/DOT system provided better PAT images when the targets were smaller in size and located near the center of the background phantom, while better DOT images were obtained when the targets were larger in size and located away from the center of the background. The successful results obtained from both the phantom andex vivo experiments will allow us to test the hybrid system in humans with breast cancer in the near future.
Exploring spherical microphone arrays for room acoustic analysis
Authors: Meyer Jens , Elko Gary W.
Published: April 2012

Spherical microphone arrays offer several advantages over linear microphone arrays and single sensor microphones for room acoustic analysis. Some advantages are the ability to: a) steer the directional response in 3D space, b) change the beampattern shape (independent of the look direction) and c) spatial decomposition of the sound field into spherical harmonic orthonormal components. All of these features are available online and offline meaning that the analysis can be performed after the measurement has been done. We will present standard measurements such as spatially dependent reverberation time, diffuseness, etc. that take advantage of the spherical array decomposition of the soundfield. We will also revisit the spatial correlation function, a measure very suitable for sphercial array based room analysis. Results for various setups will be presented.
Systematic design of reversal flow mufflers by topology optimization
Authors: Lee Jin Woo
Published: April 2012

A new muffler design method is suggested for systematic design of reversal flow mufflers. In the new method, a muffler design problem is reformulated as an acoustical topology optimization problem, where the transmission loss at the frequency of interest is maximized. A finite element model is employed for acoustical analysis, and one design variable is assigned to each finite element and changes continuously from zero to one. When the design variable becomes one, the associated finite element is filled with rigid body and an incident acoustic wave is fully reflected. The rigid bodies build up partitions, which improve the acoustical characteristics of flow-reversing chambers. When the design variable becomes zero, an incident acoustic wave is freely transmitted to the other side. Since the optimal location and length of the partitions are determined automatically by the suggested muffler design method, the internal configuration of the reversal flow mufflers does not depend on the designers' intuition and experiences. Several numerical results prove the feasibility of the suggested muffler design method.
New semi-active muffler system based on the H-Q tube concept
Authors: Liu Xueguang , Yin Changchun , Wang Ye , Cui Shiming , Li Chunxia
Published: April 2012

For a fixed bandwidth noise, the appropriate control device is used to change the internal structure of the semi-active muffler to get the large amount of noise reduction. This paper analyzes the principle of Hershcel-Quincke tube, then according to the principle of the Hershcel-Quincke tube, a semi-active silencing device is presented here, which can effectively control the noise. Then a test bench basing on the design is built. The control system which includes the control of the valves and the stepping motor is studied here. In the conditions without flow, the acoustic characteristic testing has been done using the control systems. It shows that the valves and the stepping motor have a rapid response, meanwhile, the testing results are identical with the theoretical control state, which achieves the control of the semi-active muffler. According to the analysis of the testing results, the muffler has a good noise reduction effect to low frequency noise and the harmonic frequency noise corresponding to the low frequency. It shows an average noise reduction of 10dB as well as the maximum noise reduction approaching to 35dB, which reveals the excellent noise reduction characteristic of the muffler.
Analysis of Korean head-related transfer function
Authors: Ju Yongwon , Park Youngjin , Son Daehyuk , Lee Seokpil
Published: April 2012

It is necessary to construct head-related transfer function database for rendering and studying three dimensional audio. For this reason, many research groups have tried to develop a HRTF measurement system and to construct a HRTF database for their research. Even though there are various HRTF databases, there is no database with anthropometry in public domain aimed at Koreans even if the HRTFs vary based on physical shapes of subjects. Because Koreans hear three dimensional sound rendered by HRTF database based on Caucasians, performance of three dimensional sound might be hindered. To verify this possibility and remedy the drawbacks of established HRTF database, construction of new HRTF database aimed at Korean is needed. For constructing HRTF database, new HRTF measuring system using sine sweep signal was developed and the HRTFs for 10 subjects at 49 different elevation and 36 different azimuths at 5angular increments were measured. By using measured HRTFs, the HRTFs aimed at Koreans were compared with CIPIC HRTF database and analyzed.
Dual-layer loudspeaker array for multiple listening zones
Authors: Fazi Filippo M. , Hirono Fabio , Nelson Philip A.
Published: April 2012

A dual-layer array consisting of sixteen small (1″) loudspeakers has been built for simultaneous transmission of audio signals to multiple listeners occupying different regions of the space. The audio signals are filtered through a bank of FIR filters, computed using a Least Mean Squares (LMS) approach with regularization. The plant matrix of the array, representing the transfer functions between the loudspeakers and a set of control points, was measured in the anechoic chamber of the ISVR and was used in the filter matrix calculation. It is shown that the selection of both the number and location of the control points has direct impact on the condition number of the plant matrix, on the frequency response of the digital filters, on the frequency response of the reproduced signals, and on the acoustic radiation pattern of the array. Results are shown for several application cases, which demonstrate also the capability of controlling independently the sound radiation to the front and to the back of the dual-layer array.
A hybrid approach for simulation of room reverberation
Authors: Li Junfeng , Xia Risheng , Yan Yonghong
Published: April 2012

Simulation of room reverberation plays an important role in room acoustics, virtual surround sound and 3D audio. Traditional reverberation simulation approaches, e.g., the geometric technique (e.g., image method) and digital signal processing-based technique, suffer from the inefficient and unnatural problems. In this paper, we propose a hybrid approach for simulation room reverberation in which the early reflections are generated using the image method with low reflection order and the late reverberation is simulated using the digital signal processing based technique. The main focus of this paper is given to realize the smooth transition from early reflection to late reverberation without any audible artifacts. Specifically, the energy decay curve (EDC) of the early reflections modeled by the image method is first formulated and subsequently exploited for late reverberation generation by the feedback delay network (FDN) approach. The subjective and objective experiments demonstrate the effectiveness of this proposed hybrid reverberation simulation approach.
Horizontal and vertical sound image control using multiple parametric speakers
Authors: Maeda Kumi , Nishino Takanori , Naruse Hiroshi
Published: April 2012

Stereophonic sound systems, such as a 5.1-ch surround system, are becoming more popular because they control horizontal sound localization; however, their vertical localization remains unsatisfactory. In this paper, a method that controls a sound image with four parametric speakers are proposed and evaluated. These parametric speakers have 50 ultrasonic transducers with 10 mm diameters on the substrate and achieve super-directivity using frequency modulation. Proposed system uses sounds that are reflected on a wall and controls the sound images based on the sound level differences among parametric speakers. The sound localization performances were evaluated by subjective tests. From the results, horizontal sound localization was roughly achieved; however, vertical sound localization was difficult. [Work supported by the Hoso Bunka Foundation.]
A simplified crosstalk cancellation method for multichannel audio equalization
Authors: Ye Qinghua , Yang Hefei , Li Xiaodong
Published: April 2012

In deviation from the ideal listening environment, multichannel loudspeaker equalization can improve the listening experience. In this paper a multichannel equalization method based on crosstalk cancellation is presented. The basic idea is to estimate the real and desired spatial location or acoustic transfer function for each loudspeaker, and design the equalization filters by a simplified crosstalk cancellation algorithm. The process can be divided into three steps. Firstly, the loudspeakers emit uncorrelated signals simultaneously, while the spatial location and transfer function of each loudspeaker can be measured using a binaural microphone pair. Transfer functions of other desired directions can also be measured by head rotation. Secondly, set the expected loudspeaker configuration, and get the transfer functions between the expected speakers and the listening position utilizing physical model or measuring results from previous step. Finally, the equalization filters are calculated by means of a simplified and robust multichannel crosstalk cancellation algorithm. This method can achieve equalization quickly and easily for multi-loudspeaker systems, and its effectiveness is verified by comparison with other equalization methods.
Tonal features of Chinese plucked string instruments extracted from constant-Q transform spectrum
Authors: Liu Jing , Xie Lingyun
Published: April 2012

The tonal features can demonstrate some musical acoustical characteristics of a musical instrument. The Constant-Q Transform (CQT) transforms temporal signal into logarithmically spaced frequency domain, which suits musical content very well. To analyze the sound of the notes played on Chinese plucked string instruments, this paper proposed an algorithm to draw the chromagram used for extracting tonal features and recorded four Chinese plucked string instruments. The classic brute force method for CQT was employed to produce the spectrograms of notes which were tuned and mapped to obtain the chromagrams. Tonal features were then extracted from them and proved to be informative for analyzing the timbre of Chinese plucked string instruments.
Sound power level measurement of Chinese bowed stringed instrument-Gaoyinbanhu
Authors: Li Nan , Zhao Yuezhe , Wu Shuoxian , Huang Hong , Wu Liling
Published: April 2012

Gaoyinbanhu is a kind of Chinese traditional musical instrument which is popularly used in the north of China. This instrument and other two-bowed stringed instruments are adapted to play Chinese traditional musical scales and melodies which are composed with 5 notes. In this paper the sound power level measurements of Gaoyinbanhu were performed in a semi-anechoic chamber. Two professional musicians were invited to perform on their own instrument. 10-channels acoustic measuring equipments were used to investigate the sound power level and the dynamic ranges when single notes, musical scale and melodies are performed under pp, mp, f and ff dynamics. It was found that both the sound power level and its spectrum were quite close when music scale was performed under f dynamic to that when melodies were performed under normal dynamic mark. Thus the typical sound power level of Gaoyinbanhu instruments can be represented by the radiated sound power levels when musical scale was performed under f dynamic marking.
Development of long-term data acquisition system of noise exposure and personal behavior for analysis of health risk: Measuring equipments
Authors: Yonemoto Yuichi , Ohya Masaharu , Imaizumi Hiroyuki , Fujimoto Kazutoshi , Anai Ken , Hiraguri Yasuhiro
Published: April 2012

We have built a trial prototype of a long-term data acquisition system of individual noise exposure (hereafter referred to as HIKE) and have carried out technical verification of the system. HIKE consists of a noise exposure meter, a thermohygrometer, an illuminometer, and a smartphone. HIKE continuously measure LAeq,1s and global positions of subjects in daytime, and in addition environmental parameters such as atmospheric temperature, relative humidity and illumination in nighttime. The noise exposure meter should be as small and light as possible for the portability and equip longer battery-life to realize the long-term data acquisition. Global positioning system on the smartphone is utilized to detect the position of subject, and we have newly developed original software for integrating the functions of collecting, storing, and displaying all data measured on the smartphone. Wireless network is applied to connect the smartphone with other measuring equipments for convenience of long-term measurement, and to accumulate all data on a database server successively and prepare for health risk analyses. This report presents the system specification and the technical considerations for setting up HIKE.
Self-nucleated nuclear effect of acoustic cavitation in focusing acoustic field
Authors: Cheng Qian , Li Xin-Nian , Qian Meng-Lu , Wang Yin-Guan
Published: April 2012

Bubble fusion have been discussed for a decade since Taleyarkhan' reported that fusion could take place under the condition of acoustic cavitation at SCIENCE in 2002, and a lot of theoretical and experimental investigations have been engaged to probe the nuclear effect of acoustic cavitation (NEAC). The self-nucleated NEAC in focusing acoustic field is preliminary investigated in this paper. The 5.5 MeV alpha particles from radioactive Am241 sheets placed in heavy water for bubble nucleation are used to avoid the possible influence of external incident neutrons on the counting of emitted neutrons. In consideration of the penetration depth of alpha particles in heavy water is very small (~ 40 μm) due to its heavily ionizing radiation, different focusing acoustic transducers are designed in order to focus the acoustic energy around Am241 sheets. The experimental datas show that the cavitation counts Ccav.on, is higher than the cavitation-free counts Ccav.off, and the neutron increment ▵C, i.e. the difference between Ccav.on and Ccav.off, is statistically significant. Besides, the tritium content of the test liquids also increases. The experiment results verify that self-nucleated acoustic cavitation in focusing acoustic field can help to intensify nuclear effect. One of the reasons may be that the cavitation bubbles increase the collision cross section of deuterium. This work is supported by the National Natural Science Foundation of China (No. 10974145 and 10804085)
Sound radiation of elastically restrained stiffened orthotropic plates
Authors: Kam Tai Yan , Lee B. Y.
Published: April 2012

In this paper, a method is proposed for studying the sound radiation behaviors of elastically restrained stiffened orthotropic plates. The plate stiffened by a number of relatively thick beams on the bottom surface of the plate is elastically restrained around the periphery of the plate. In the vibro-acoustic analysis of the plate, the deformation of the stiffened plate is formulated based on the first-order shear deformation theory and the peripheral elastic restraint modeled as a set of distributed springs. The Ritz method is used to construct the equations of motion for the elastically restrained stiffened plate. The response (amplitudes and phases) at any point on the top surface of the plate subjected to harmonic excitation is used in the Rayleigh first integral to calculate the sound pressure generated by the plate. The sound pressure level (SPL) curve of the plate in the audible frequency range (20-20kHz) is constructed for the plate. The proposed method is then used to study the effects of material properties and stiffened pattern on the SPL curve of the elastically restrained stiffened orthotropic plate. The experimental SPL curves of two elastically restrained stiffened orthotropic plates are determined to verify the accuracy of the theoretical results and demonstrate the applications of the proposed method in the audio industry.
Power flows between strongly coupled structural components
Authors: Jiang Shiliang , Li Wen L , Yang Tiejun , Du Jingtao
Published: April 2012

In this study, the energy distributions and power flows between some basic structural components such as beams, plates, and shells are studied using a so-called Fourier Spectral Element Method (FSEM). Similar to the SEA modeling, a complex system is here also considered as an assembly of subsystems or components. The FSEM, however, is deterministic in nature in that the solution is obtained by directly and faithfully solving the governing equations for each component under the actual boundary and coupling conditions. What make this model powerful and unique lie in its capability and flexibility of effectively dealing with model uncertainties (due to the probabilistic/stochastic natures of some model parameters) and engineering and manufacturing errors which tend to become critically important at higher frequencies. Since this method does not involve any artificial assumptions or simplifications, it potentially offers a whole frequency solution with adaptive spatial and frequency resolutions.
Energy flux streamlines versus acoustic rays for modeling interaction with rigid boundaries: a Lloyd's mirror experiment
Authors: Dean Cleon E. , Braselton James P.
Published: April 2012

An energy flux streamline model was developed in support of a simple Lloyd's mirror experiment originally intended for use by high school students wherein 10 000 Hz harmonic sound, emitted from a roughly 10 cm diameter baffled loudspeaker, was reflected off a floor, treated as a rigid boundary. The model is used to draw out similarities and differences between energy flux streamlines and acoustic rays. Particular attention is paid to conditions and angles of reflection that hold for acoustic rays reflected from a rigid boundary versus the conditions that hold for the equivalent reflection and reflection angles of energy flux streamlines.
Transient dynamics of three-dimensional beam trusses using higher order kinematics
Authors: Guennec Yves Le , Savin Eric
Published: April 2012

Spatial structures are often subjected to impulse loads which induce high-frequency (HF) wave propagations. Despite some recent researches, the characterization of the transient response to such loads remains an open problem. The objective of this research is to develop a reliable model of the HF energy evolution within three-dimensional beam trusses in order to predict, for example, their potential steady state behavior at late times or the energy paths. The theory of micro-local analysis of wave systems shows that the energy density associated with their HF solutions satisfies a Liouville-type transport equation. A suitable HF transport model for beams is derived from the spectrum relations for Lamb waves in the HF range. At the interfaces between substructures, the energy flow is partly reflected and partly transmitted. The corresponding reflection/transmission coefficients are also derived in this study. Numerical simulations are performed by a spectral discountinuous Galerkin (DG) method for spatial resolution and a strong stability-preserving Runge-Kutta (RK) method for time integration. Numerical results using the RK-DG method are presented for the example of a three-dimensional beam truss that exhibit diffusive behavior at late times.
Three- to five-year-old children in Taiwan show little development in their production of monosyllabic Mandarin lexical tones
Authors: Wong Puisan
Published: April 2012

While a couple of studies reported that 2-year-old children in Beijing have mastered the production of Mandarin tones in various contexts, several studies found that three-year-old children learning Mandarin as a first language in the U.S. have not produced adult-like tones in monosyllabic words. This study collected monosyllabic Mandarin tone productions from 33 three- to five-year-old children growing up in Taiwan. Five judges categorized the tones of the 734 child productions and 92 productions by 4 adults via low-pass filtered words in which the segmental information was degraded while F0 information was retained. Adult tones were categorized with 93%, 96%, 82%, and 94% accuracy. Children's tones were identified with significantly lower accuracy (p<.05) at 63%, 50%, 50% and 77%, respectively. Age accounted for 0.2%, 2.4%, 4.0% and 8.2% of the variance in children's accuracy of the four tones, respectively, suggesting little developmental change. Children produced T4 more accurately than T1. T2 and T3 were significantly more difficult. These results are in line with findings in previous studies with children growing up in the U.S. using the same methodology and seem to support that tone development is related to maturation of speech motor control. [Work supported by NSF EAPSI]
Hybrid low delay frame loss concealment in an MDCT based audio codec
Authors: Lin Zhibin , Wu Ming , Lu Jing , Qiu Xiaojun
Published: April 2012

By combining tonal-dominant and noise-dominant signal frame loss concealment (FLC) approaches, a hybrid low delay FLC method is proposed for an modified discrete cosine transform (MDCT) based codec. Based on the observations that the phase of the MDCT-MDST (modified discrete sine transform) coefficients of tonal-dominant signals decreases linearly with the increase of the frame index and the amplitude keeps unchanged, the tonal-dominant signal FLC approach uses the frame interpolation to estimate the phase and magnitude of the MDCT-MDST coefficients of the lost frame while the noise-dominant signal FLC method implements a modified shaped-noise insertion. Both objective and subjective test results show that the proposed technique provides better performance than the existing methods for music signals and voiced speech signals.
Improved acoustic models for spontaneous speech recognition
Authors: Zhang Qingqing , Cai Shang , Pan Jielin , Yan Yonghong
Published: April 2012

This paper describes advances for acoustic models in Chinese spontaneous Conversational Telephone Speech (CTS) recognition task. A number of approaches were investigated in the acoustic modeling, including Heteroscedastic Linear Discriminant Analysis (HLDA), Vocal Tract Length Normalization (VTLN), Gaussianization, Minimum Phone Error (MPE), Feature space MPE (fMPE), and etc. Considering pronunciation variations in continuous speech, tones in recognition vocabulary were modified due to the Sandhi rule. The acoustic models were trained on over 200 hours of audio data from standard LDC corpora. The improved acoustic models reduce the relative Character Error Rate (CER) by about 25% over the baseline acoustic models on standard LDC test set and China 863 program evaluation data set. Acknowledgment: This work is partially supported by the National Natural Science Foundation of China (No's. 10925419, 90920302, 10874203, 60875014, 61072124, 11074275, 11161140319).
Passive vs active geoacoustic inversion with a compact receiver array (MREA/BP'07 sea trials)
Authors: Hermand Jean-Pierre , Carrière Olivier , Ren Qunyan
Published: April 2012

MREA/BP'07 sea trials were an interdisciplinary experimental effort that aimed at addressing novel concepts of Maritime Rapid Environmental Assessment in shallow waters. Southeast of Elba island in Mediterranean sea, several standard and advanced techniques of environmental characterization covering the fields of underwater acoustics, physical oceanography and geophysics were combined within a coherent scheme of data acquisition, processing and assimilation. Broadband (0.2-1.6 kHz) active and passive sounds propagated over ranges on the order of 1 km have been used to extract information about the ocean and subbottom environments. This paper compares the results of different inversion methods: 1) global optimization and sequential Bayesian filtering applied to matched-field (MFP) and model-based matched filter (MBMF) processed multitone and frequency-modulated data, respectively, and 2) local feature analysis of striations extracted from interference data due to ship noise. The approaches only require a compact and sparse hydrophone array which is easily deployable from small vessels giving similar estimates of the bottom geoacoustic properties for assimilation into hybrid MREA schemes.
Artec concert halls - a new generation
Authors: Doria Damian J. , Arenius Edward P. , Nakajima Tateo , Brooks Todd L.
Published: April 2012

In 2011, Artec opened new concert halls in Carmel, IN (USA), Reykjavik (Iceland), and Montreal (Canada). These three halls, each quite different from each other, indicate the directions that Artec's leadership will pursue and develop in the future. As on any major concert hall project, each tells a complex story about the Client's ambitions, expectations, resources and unforeseen challenges, as well as the interpersonal dynamics of the design teams. The differences of these halls development and final design will be discussed in regards to the acoustic adjustability, plan and sectional conformation, and the connection of the programming of each room relationship to its final form.
Sound levels in rehearsal and medium sized concert halls; are they too loud for the musicians?
Authors: Gade Anders Christian
Published: April 2012

After the EU directive related to sound exposure in the work environment became valid also for the music industry in February 2008, managers of symphony and opera orchestras in Europe should now pay serious attention to the sound levels to which their musicians are exposed. In this context, it is often discussed whether some halls are simply too small to accommodate the large sound power output of a symphony orchestra. Based on measurements of sound exposure levels of musicians according to ISO 9612 in both performance and smaller rehearsal halls, as well as room acoustic measurements in a number of small sized halls that we have designed, it is discussed whether this is likely to be true.
A model to predict measurement uncertainties due to loudspeaker directivity and its validation
Authors: Witew Ingo , Knüttel Tobias , Vorländer Michael
Published: April 2012

In order to improve the understanding of uncertainties in measuring the acoustics in auditoria, the influence of a sound source's directivity is investigated. In previous work a model to predict the uncertainties when measuring room impulse responses with sources of a given directivity pattern has been developed. As a result, properties of the measurement environment, i.e. the size of the room, its reverberation as well as the sound scattering behaviour of the room surfaces, were identified to be significant secondary influences. Through extensive series of scale measurements data has been collected in a reverberation room to validate the model prediction. By introducing adjustable partition panels, absorbing and sound scattering surface elements the secondary influence factors were carefully controlled over a large range of values. After a brief explanation of the uncertainty model the results of the validation measurements will be presented. The significance of the different influence factors on the measurement uncertainty will be discussed.
The impact of microbubbles on measurement of drug release from echogenic liposomes
Authors: Kopechek Jonathan , Haworth Kevin , Radhakrishnan Kirthi , Huang Shaoling , Klegerman Melvin , McPherson David , Holland Christy
Published: April 2012

Echogenic liposomes (ELIP) are under development to enable ultrasound-triggered drug delivery. The mechanisms of ultrasound-mediated drug release from ELIP are not well understood. The effect of cavitation activity on drug release from ELIP was investigated in flowing solutions using two fluorescent molecules: a lipophilic drug (rosiglitazone) and a hydrophilic drug substitute (calcein). ELIP samples were exposed to pulsed Doppler ultrasound from a clinical diagnostic ultrasound scanner at pressures above and below the inertial and stable cavitation thresholds. Control samples were exposed to Triton X-100, a detergent (positive control), or to flow alone (negative control). Fluorescence techniques were used to detect release. Encapsulated microbubbles reduced the measured fluorescence intensity. This effect should be considered when assessing drug release if microbubbles are present. Release of rosiglitazone or calcein compared to the negative control was only observed with detergent treatment, but not with ultrasound exposure, despite the presence of inertial or stable cavitation activity. Thus, cavitation activity did not correlate with release of rosiglitazone or calcein from ELIP using a clinical diagnostic ultrasound scanner. These findings lay the foundation for future studies of ultrasound-mediated drug delivery with ELIP.
Piezoelectric effect of cell's membrane
Authors: Cheng Qian , Qian Meng-Lu
Published: April 2012

In this paper, the piezoelectric effect of cell's membrane at nano-scale is preliminary investigated. For a eukaryotic cell, either it or every organelle in it is enclosed in a similar membrane made of the phospholipid bilayer. A lot of cell's physiological activities, such as signal transduction, ion transport and macromolecules delivery, realize through the membranes. Fundamentally, the realization of these physiological functions originates from the physical properties of the phospholipid bilayer. Here, the detection results of the dynamic piezoelectric effect of the plasma membrane and the nuclear envelope of rat A7r5 aorta smooth muscle cell at nano-scale using PFM are present. The results verify that cell membrane is piezoelectrically active due to ordered arrangement of polar phospholipid molecules in the liquid crystalline state. Consequently, this indicate that the ultrasound acting on the membrane structure will lead to the change of membrane potential, suggesting the piezoelectricity of cell membrane maybe play key roles in physiological activities of cells, further in drug/gene delivery, cancer treat, and so on. This work is supported by the National Natural Science Foundation of China (No. 10804085 and 11174223)
Acoustic cavitation and sonoporation involved in ultrasound-assisted gene transfection with polyethylenimine in vitro
Authors: Tu Juan , Zhang Dong , Li Qian , Fan Tingbo
Published: April 2012

It has been shown that, acoustic cavitation-induced sonoporation should play an important role in the enhancement of gene/drug delivery. However, obstacles still remain to achieve controllable sonopration outcomes. In the current work, MCF-7 cells mixed with PEI: DNA complex were exposed to 1-MHz ultrasound pulses with varied acoustic peak negative pressure, total treatment time, and pulse-repetition-frequency (PRF). The IC activities were detected using a passive cavitation detection (PCD) system and quantified as inertial cavitation dose (ICD). The DNA transfection efficiency was evaluated using flow cytometry and the cell viability was examined by PI dying assessment. Then, scan electron microscopy was used to investigate the sonopration effects on the cell membrane. The results show that: (1) the ICD generated during US-exposure could be affected by US parameters; (2) the pooled data analyses demonstrated that DNA transfection efficiency initially increased linearly with the increasing ICD, then tended to saturate instead of trying to achieve a maximum value while the ICD kept going up; and (3) the measured ICD, sonopration pore size, and cell viability exhibited high correlation among each other. All the results indicated that ICD could be used as an effective tool to monitor and control the US-mediated gene/drug delivery effect.
Microseconds vaporization dynamics of superheated droplets upon triggering with focused ultrasound
Authors: Shpak Oleksandr , Kokhuis Tom , Fowlkes Brian , de Jong Nico , Versluis Michel
Published: April 2012

Liquid emulsion nanodroplets composed of perfluorocarbon (PFC) and a drug (Doxorubicin) are currently being studied as a potential highly efficient system for tumor imaging and for local drug delivery. The nanodroplets have the ability to extravasate through hyperpermeable tumor blood vessel walls, and to accumulate in interstitial tissue. The extravasated droplets can be triggered and vaporized with focused ultrasound, converting them into gas bubbles while the encapsulated drugs are released during the explosive evaporation of the droplet. Single and double emulsions of PFC-in-water and oil-in-PFC-in-water upscaled to 5-10 um size were prepared and the nucleation and growth of the vapor bubbles (f=3.5 MHz, P_=4.5 MPa) was imaged at frame rates of up to 20 Mfps with the Brandaris ultra high-speed imaging facility. The recorded images provide new and detailed insight in the physical mechanisms associated with the vaporization dynamics. This include droplet deformation and oscillatory motion along with surrounding fluid with an amplitude of 200-400 nm, rapid growth of a vapor nucleus with a speed of 40 m/s and consecutive oscillations and collapse of several bubbles.