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941.
First available appraisals for 67,644 Jersey cows were used to estimate relative magnitudes of additive and selected sources of nonadditive genetic variance and covariance for 13 type traits scored linearly from 50 to 99 points. Covariances among four types of relatives were used to estimate components of genetic variance and covariance for each of the 13 traits. Direct additive, direct dominance, and additive maternal genetic variances and the direct-maternal additive genetic covariance were estimated using covariances among paternal half-sibs, full-sibs, daughters and dams, and maternal half-sibs. Estimates of additive genetic variance were 11 to 36% of variance within herd-appraiser subclasses with largest values for stature, strength, rump angle, rump width, and udder depth. Dominance components were two to four times the magnitude of additive components for dairy character, rump width, fore udder, rear udder height, rear udder width, and suspensory ligament but much smaller for other traits. Maternal effects and the direct-maternal additive genetic covariance appeared small for all linear type traits. 相似文献
942.
Our goal is to develop a robust out-of-core sorting program for a
distributed-memory cluster. The literature contains two dominant
paradigms for out-of-core sorting algorithms: merging-based and
partitioning-based. We explore a third paradigm, that of oblivious
algorithms. Unlike the two dominant paradigms, oblivious algorithms
do not depend on the input keys and therefore lead to predetermined
I/O and communication patterns in an out-of-core setting.
Predetermined I/O and communication patterns facilitate overlapping
I/O, communication, and computation for efficient implementation. We
have developed several out-of-core sorting programs using the paradigm
of oblivious algorithms. Our baseline implementation, 3-pass
columnsort, was based on Leighton's columnsort algorithm. Though
efficient in terms of I/O and communication, 3-pass columnsort has a
restriction on the maximum problem size. As our first effort toward
relaxing this restriction, we developed two implementations: subblock
columnsort and M-columnsort. Both of these implementations
incur substantial performance costs: subblock columnsort performs
additional disk I/O, and M-columnsort needs substantial
amounts of extra communication and computation. In this paper we
present slabpose columnsort, a new oblivious algorithm that we have
designed explicitly for the out-of-core setting. Slabpose columnsort
relaxes the problem-size restriction at no extra I/O or communication
cost. Experimental evidence on a Beowulf cluster shows that unlike
subblock columnsort and M-columnsort, slabpose columnsort runs
almost as fast as 3-pass columnsort. To the best of our knowledge,
our implementations are the first out-of-core multiprocessor sorting
algorithms that make no assumptions about the keys and produce output
that is perfectly load balanced and in the striped order assumed by
the Parallel Disk Model. 相似文献
943.
Eva M. Valero Juan L. Nieves Sérgio M. C. Nascimento Kinjiro Amano David H. Foster 《Color research and application》2007,32(5):352-360
Many spectral‐recovery methods using RGB digital cameras assume the underlying smoothness of illuminant and reflectance spectra, and apply low‐dimensional linear models. The aim of the present work was to test whether a direct‐mapping method could be used instead of a linear‐models approach to recover spectral radiances and reflectances from natural scenes with an RGB digital camera and colored filters. In computer simulations, a conventional RGB digital camera with up to three colored filters was used to image scenes drawn from a hyperspectral image database. Three measures were used to evaluate recovery with the direct‐mapping method: goodness‐of‐fit, root‐mean‐square error, and a color‐difference metric. It was found that with two and three filters both spectral radiances and reflectances could be recovered sufficiently accurately for many practical applications. With little increase in computational complexity, an RGB camera and a few colored filters can provide significantly better recovery of natural scenes than an RGB camera alone. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 352–360, 2007 相似文献
944.
945.
A synthesis procedure for generating current conveyor active filters is presented, and a novel network which realises the general 2nd-order voltage transfer function is given.<> 相似文献
946.
Two techniques for the design and fast search of a vector quantiser codebook are proposed. These classify speech data vectors according to (i) the sign and (ii) the slope between successive samples. With both techniques the performance obtained is superior to that obtained from a conventional gain/shape vector quantiser and comparable to that of a full search vector quantiser. A major attraction of both approaches is that they significantly reduce the number of computations required for the codebook search. 相似文献
947.
Blair J.D. Correale A. Jr. Cranford H.C. Dombrowski D.A. Erdelyi C.K. Hoffman C.R. Lamphere J.L. Lang K.W. Lee J.K. Mullen J.M. Norman V.R. Oakland S.F. 《Solid-State Circuits, IEEE Journal of》1989,24(6):1647-1655
The authors describe a 9.02×9.02-mm chip built in 1-μm CMOS with two levels of metal and an additional mask level for fabricating capacitors. It contains both analog and digital circuits and has provisions for self-test. The function includes the transmitter, receiver, protocol handler, an microprocessor, as well as interfaces for RAM/ROM storage, IBM PC bus, IBM PS/2 bus, IBM 3174 bus, and Motorola 68000 bus. The physical design terrains are formed by 24K circuits of standard cell gates, a 10K-circuit equivalent hand-honed custom microprocessor, and an analog macro. The chip operates from a single 5-V supply, and the power consumption is 0.8 W nominal at 16 Mb/s. The chip can also be operated at 4 Mb/s 相似文献
948.
The digital multistep method generates uniform pseudorandom numbers by transforming sequences of integers obtained by multistep recursions. The statistical independence properties of these pseudorandom numbers depend on the characteristic polynomial of the recursion. We describe a method of calculating characteristic polynomials that are optimal with respect to statistical independence of pairs of successive pseudorandom numbers. Tables of such optimal characteristic polynomials for degrees ≤64 are included. 相似文献
949.
SIMULATION OF THAWING OF FOODS USING FINITE ELEMENT METHOD 总被引:2,自引:0,他引:2
950.