581 research outputs found

    Aluminum-silicon eutectic alloy improves electrical and mechanical contact to silicon carbide

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    Alloy contact layer is made at relatively low temperature and has good wetting characteristics. Contacts adhere well to silicon carbide surface, penetrating about 300 to 500 angstroms into it. Contacts are ohmic on p-type silicon carbide and blocking on n-type

    Copper-titanium eutectic alloy improves electrical and mechanical contact to silicon carbide

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    Contact preparation at low temperatures is possible with the use of a copper-titanium eutectic alloy. Contacts formed with this alloy are ohmic on p-type silicon carbide and rectifying on n-type

    Optical and near infrared photometry of Butcher-Oemler clusters

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    Rich clusters of galaxies at moderate redshifts (z approx. .3) have a larger proportion of optically blue galaxies than their low redshift counterparts. Spectroscopic examination of the blue galaxies by various authors has shown that the blue galaxies are generally Seyferts, show evidence for recent star formation, or are foreground objects. Unfortunately, spectroscopy is too time consuming to be used on large samples. Thus, we have looked for a way to separate Seyferts, starbursts, ellipticals and nonmembers using photometry alone. Five moderate redshift clusters, Abell numbers 777, 963, 1758, 1961 and 2218, have been observed in the V, R and K bands. We model the spectral energy distributions of various kinds of galaxies found in clusters and derive observed colors. We have modeled the spectral energy distributions (SED) of several kinds of galaxies and compute their colors as a function of redshift. We expect to see ellipticals, spirals, starbursts, post-starburst and Seyfert galaxies. The SED of elliptical and Sbc galaxies was observed by Rieke and Rieke. The SEDs for the starburst galaxies was created by adding a reddened 10(exp 8) year old burst to a spiral galaxy SED. The post-starburst (E+A) galaxy SEDs are composed of a slightly reddened 10(exp 9) year old burst and elliptical galaxy SED. SEDs for the Seyferts were created by adding a v(exp -1.1) power law, and a hot dust thermal spectrum to the Sbc. From the SEDs the colors of galaxies at various redshifts with assorted filters were computed. Lilly & Gunn (1985) have optical and infrared photometry for a sample of galaxies in CL0024+1654 observed spectroscopically by Dressler, Gunn and Schneider (1985). We have used this data to choose the most appropriate SEDs for our starburst and post-starburst models. The most likely explanation for the optically blue colors in most cluster galaxies is star formation. Very few galaxies lie in the Seyfert locus. Abel 1758 has more Seyfert candidates than the other clusters, we observed. It seems possible to roughly sort types of galaxies in clusters by color alone. The cluster population seems to vary considerably between clusters, but our K selected sample has few Seyferts in any cluster

    Structural factoring approach for analyzing stochastic networks

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    The problem of finding the distribution of the shortest path length through a stochastic network is investigated. A general algorithm for determining the exact distribution of the shortest path length is developed based on the concept of conditional factoring, in which a directed, stochastic network is decomposed into an equivalent set of smaller, generally less complex subnetworks. Several network constructs are identified and exploited to reduce significantly the computational effort required to solve a network problem relative to complete enumeration. This algorithm can be applied to two important classes of stochastic path problems: determining the critical path distribution for acyclic networks and the exact two-terminal reliability for probabilistic networks. Computational experience with the algorithm was encouraging and allowed the exact solution of networks that have been previously analyzed only by approximation techniques

    Cereal variety trials - Results for 1954/55 season

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    Cereal variety trials are carried out each season to determine the relative yielding ability of varieties produced in this State or introduced from other States. After harvest, grain samples from each wheat trial are forwarded to the Cereal Research laboratory for flour quality tests

    Wheat variety trails on research stations, 1953

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    Each season, wheat variety trials are carried out at the research stations to compare the yielding ability of new varieties produced in this and other Australian States with standard varieties under commercial cultivation. Locally-produced crossbreds included in these trials have been developed to meet the demand for highyielding varieties suited to local conditions. Particular attention has been paid to better straw strength, disease resistance and to improved baking quality

    Wheat and barley trials, 1956-57

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    The results of cereal variety trials on wheatbelt research stations and also a barley trial on the property of Messrs. Hamilton Bros., Moora, are included in two separate articles in this Journal. Trials with wheat and barley are discussed in this article, while the oat variety trials have been incorporated into Oat Trials and Usage in the Wheatbelt, 1956. (See page 551.

    A review of agriculture on the Esperance Downs

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    Esperance is approaching a period of rapid development based on the results of research at Esperance Downs Research Station and on farmers\u27 properties in the area. This article reviews the soils, vegetation, climate, agricultural development and development costs of the area

    A review of differentiable digital signal processing for music and speech synthesis

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    The term “differentiable digital signal processing” describes a family of techniques in which loss function gradients are backpropagated through digital signal processors, facilitating their integration into neural networks. This article surveys the literature on differentiable audio signal processing, focusing on its use in music and speech synthesis. We catalogue applications to tasks including music performance rendering, sound matching, and voice transformation, discussing the motivations for and implications of the use of this methodology. This is accompanied by an overview of digital signal processing operations that have been implemented differentiably, which is further supported by a web book containing practical advice on differentiable synthesiser programming (https://intro2ddsp.github.io/). Finally, we highlight open challenges, including optimisation pathologies, robustness to real-world conditions, and design trade-offs, and discuss directions for future research
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