Waveguide physical modeling of vocal tract acoustics: flexible formant bandwidth control from increased model dimensionality

Digital waveguide physical modeling is often used as an efficient representation of acoustical resonators such as the human vocal tract. Building on the basic one-dimensional (1-D) Kelly-Lochbaum tract model, various speech synthesis techniques demonstrate improvements to the wave scattering mechanisms in order to better approximate wave propagation in the complex vocal system. Some of these techniques are discussed in this paper, with particular reference to an alternative approach in the form of a two-dimensional waveguide mesh model. Emphasis is placed on its ability to produce vowel spectra similar to that which would be present in natural speech, and how it improves upon the 1-D model. Tract area function is accommodated as model width, rather than translated into acoustic impedance, and as such offers extra control as an additional bounding limit to the model. Results show that the two-dimensional (2-D) model introduces approximately linear control over formant bandwidths leading to attainable realistic values across a range of vowels. Similarly, the 2-D model allows for application of theoretical reflection values within the tract, which when applied to the 1-D model result in small formant bandwidths, and, hence, unnatural sounding synthesized vowels

Environmental Mechanism Designs in a New Order of Regulatory Capitalism

Complexity of environmental programs is most apparent with information asymmetries, making the design of efficient mechanisms particularly challenging. As developed theoretically in this paper, a new regulatory capitalism paradigm mating voluntary agreements with environmental education can produce outcomes at least as efficient as voluntary agreements alone. Such a design exploits a key difference between voluntary agreements versus educational programs in terms of their impact on agents' incentive compatibilities. Specifically, in a principal-agent model, voluntary agreements are associated with an incentive-compatibility constraint, whereas educational programs are not. The efficient bundle will likely consist of a set of education programs and voluntary agreements. With the new order of regulatory capitalism, it is time to concentrate on removing barriers yielding inefficient mono-mechanism design and start constructing multidimensional incentives to efficiently allocate effort toward environmental and economic goals.Command and control, environmental education, environmental policy, voluntary agreements, Environmental Economics and Policy,

An Assessment of the Economic, Environmental and Social Impacts of NSW Agriculture's Wheat Breeding Program

The Wagga wheat breeding program has been operating for over 100 years. In that time, it has released a flow of new wheat varieties for wheat growers in south-eastern Australia. Those varieties have led to increases in both yields and grain quality. The average annual rate of yield improvement in NSW has been 3.2% compared to the average for Australia of 2.4% with a significant proportion of these productivity gains arising from new varieties. In this analysis, the investment in that program from 1980 to 2003 has been evaluated. Given the lags inherent in wheat breeding investments, the benefits from those investments are being measured from 1993 to 2020. The broad structure of the program has remained relatively stable for most of the period since 1980. The program consists of 2-3 wheat breeders, one breeder-pathologist, and a cereal chemist, with appropriate technical and field support, totaling approximately 15 full-time equivalents per year. The costs of the program have averaged approximately $1.2 million per year over the period. In assessing the Wagga wheat breeding program it is important to consider how the industry would have developed without the program. The benefits of the program were measured as the difference in returns from improved wheat varieties in NSW over that period and the returns that would have been achieved in the absence of the Wagga breeding program. The assumption used to determine the impact without the Wagga program was that the rate of yield improvement in NSW would have been the same as for the rest of Australia. For quality, without the Wagga program the assumption was that in southern NSW the increase in quality would have been 20$321 million. The economic benefits of the breeding program are shared by producers, processors and consumers in the wheat industry, some of whom live overseas. Because Australia is largely a price taker on world wheat markets and because the wheat processing and distribution sector in Australia is generally considered to be competitive, most of the benefits of the wheat breeding program are likely to remain with producers. However these gains are offset by declines in the world price in response to advancing technology throughout the world. These economic benefits have positive social consequences, largely through their contribution to the incomes of farmers and those who handle and process wheat in regional NSW. Some of these gains are in the form of new marketing and processing industries around the increasingly specialised industry segments resulting directly from the changes that have occurred in wheat varieties. Perhaps these new skills add to the social capital of towns in the wheat belt of NSW. In environmental terms, the wheat breeding program itself is not likely to have major impacts, since the wheat industry would have been very similar whether or not there was a Wagga breeding program. However, to the extent that improved productivity from the Wagga program's varieties has allowed an expansion of the wheat industry, there could be some negative environmental consequences of the breeding program, such as those arising from the clearing of land, increased cultivation and increased use of herbicides. On the other hand, the high levels of disease resistance developed and maintained has meant that wheat production is not associated with large-scale fungicide use, and hence the danger of chemical contamination of the environment is less than it would have been without the resistance developed in this program. Some of these environmental impacts affect the costs and incomes of wheat farmers and hence are reflected in economic benefits and some spill over to the broader community and have not been valued here. It is not clear that these social and environmental impacts would be much different without the Wagga breeding program, except through the extent to which the Wagga program has allowed the wheat industry in NSW to develop more than it otherwise would have. Without the Wagga program the slower gains in yield and quality would also be associated with some social and environmental impacts, and it is the difference that is critical in evaluating the Wagga program. The costs of this program have been met partly by the NSW taxpayers through NSW Agriculture and partly by the grains industry through levies from the Grains Research and Development Corporation (GRDC). The recent introduction of variety royalty payments ("end-point royalties") has not yet led to significant funding, but may be expected to do so in the future. The nature of the outputs of plant breeding programs is that there are large economic benefits that flow directly to producers, processors and consumers in the industry. However the social and environmental impacts on the broader community, while not explicitly valued here, are considered to be small relative to economic benefits and relative to some other programs of NSW Agriculture that have been evaluated. Hence it is appropriate that the industry, though GRDC levies and royalties on production, has increasingly funded the operations of the wheat breeding program. Recent institutional changes for the wheat breeding program have made it even more commercially-based for the future and less reliant on government funding. The new institutional arrangements for wheat breeding programs and the strengthening role of the private sector in supplying varieties traditionally supplied by the public sector mean that the place of public wheat breeding programs is being re-assessed. A key question is whether publicly-operated programs, can offer some additional benefits either to the industry or to the community, which would not result from the complete privatisation of the wheat breeding sector. While those issues have not been addressed directly in this analysis, the results indicate that past investments in public wheat breeding program at Wagga have certainly been a productive use of public funds over the past 20 years or so.Research and Development/Tech Change/Emerging Technologies,

Monograph on Computation of RF Hazards

No abstract availabl

Radiation-induced insulator discharge pulses in the CRRES internal discharge monitor satellite experiment

The Internal Discharge Monitor (IDM) was designed to observe electrical pulses from common electrical insulators in space service. The sixteen insulator samples included twelve planar printed circuit boards and four cables. The samples were fully enclosed, mutually isolated, and space radiation penetrated 0.02 cm of aluminum before striking the samples. Pulsing began on the seventh orbit, the maximum pulse rate occurred on the seventeenth orbit when 13 pulses occurred, and the pulses slowly diminished to about one per 3 orbits six months later. After 8 months, the radiation belts abruptly increased and the pulse rates attained a new high. These pulse rates were in agreement with laboratory experience on shorter time scales. Several of the samples never pulsed. If the pulses were not confined within IDM, the physical processes could spread to become a full spacecraft anomaly. The IDM results indicate the rate at which small insulator pulses occur. Small pulses are the seeds of larger satellite electrical anomalies. The pulse rates are compared with space radiation intensities, L shell location, and spectral distributions from the radiation spectrometers on the Combined Release and Radiation Effects Satellite

Discrete Lie Advection of Differential Forms

In this paper, we present a numerical technique for performing Lie advection of arbitrary differential forms. Leveraging advances in high-resolution finite volume methods for scalar hyperbolic conservation laws, we first discretize the interior product (also called contraction) through integrals over Eulerian approximations of extrusions. This, along with Cartan's homotopy formula and a discrete exterior derivative, can then be used to derive a discrete Lie derivative. The usefulness of this operator is demonstrated through the numerical advection of scalar fields and 1-forms on regular grids.Comment: Accepted version; to be published in J. FoC

The detection of tightly closed flaws by nondestructive testing (NDT) methods

Liquid penetrant, ultrasonic, eddy current and X-radiographic techniques were optimized and applied to the evaluation of 2219-T87 aluminum alloy test specimens in integrally stiffened panel, and weld panel configurations. Fatigue cracks in integrally stiffened panels, lack-of-fusion in weld panels, and fatigue cracks in weld panels were the flaw types used for evaluation. A 2319 aluminum alloy weld filler rod was used for all welding to produce the test specimens. Forty seven integrally stiffened panels containing a total of 146 fatigue cracks, ninety three lack-of-penetration (LOP) specimens containing a total of 239 LOP flaws, and one-hundred seventeen welded specimens containing a total of 293 fatigue cracks were evaluated. Nondestructive test detection reliability enhancement was evaluated during separate inspection sequences in the specimens in the 'as-machined or as-welded', post etched and post proof loaded conditions. Results of the nondestructive test evaluations were compared to the actual flaw size obtained by measurement of the fracture specimens after completing all inspection sequences. Inspection data were then analyzed to provide a statistical basis for determining the flaw detection reliability

Teegi: Tangible EEG Interface

We introduce Teegi, a Tangible ElectroEncephaloGraphy (EEG) Interface that enables novice users to get to know more about something as complex as brain signals, in an easy, en- gaging and informative way. To this end, we have designed a new system based on a unique combination of spatial aug- mented reality, tangible interaction and real-time neurotech- nologies. With Teegi, a user can visualize and analyze his or her own brain activity in real-time, on a tangible character that can be easily manipulated, and with which it is possible to interact. An exploration study has shown that interacting with Teegi seems to be easy, motivating, reliable and infor- mative. Overall, this suggests that Teegi is a promising and relevant training and mediation tool for the general public.Comment: to appear in UIST-ACM User Interface Software and Technology Symposium, Oct 2014, Honolulu, United State