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91.
J. C. Roberts C. A. Parker J. F. Muth S. F. Leboeuf M. E. Aumer S. M. Bedair M. J. Reed 《Journal of Electronic Materials》2002,31(1):L1-L6
Metal-semiconductor-metal (MSM) photodetectors have been fabricated on InxGa1−xN epitaxial films grown by metalorganic chemical vapor deposition within the composition range 0≤x≤0.13. The dark current
and spectral response were measured for devices with a varying In mole fraction x. The devices, which had nominal finger widths
and finger spacing of 5 μm, were biased with modest voltages in the range 2≤Vbias≤5 V. In general, turn-on wave-length and dark current increased with increasing x. Turn-on wavelengths ranged from λ=370
nm to 430 nm and dark current densities ranged from Idark=2×10−2 A/cm2 (Vbias=5 V, x≈0.05) to 9×104 A/cm2 (Vbias=2 V, x≈0.13) depending on the In content, x, of the device active area. 相似文献
92.
Changzhen Wang Steve Tobin Themis Parodos David J. Smith 《Journal of Electronic Materials》2006,35(6):1192-1196
The microstructure of p-n device structures grown by liquid-phase epitaxy (LPE) on CdZnTe substrates has been evaluated using
transmission electron microscopy (TEM). The devices consisted of thick (∼21-μm) n-type layers and thin (∼1.6-μm) p-type layers,
with final CdTe (∼0.5 μm) passivation layers. Initial observations revealed small defects, both within the n-type layer (doped
with 8×1014/cm3 of In) and also within the p-type layer but at a much reduced level. These defects were not visible, however, in cross-sectional
samples prepared by ion milling with the sample held at liquid nitrogen temperature. Only isolated growth defects were observed
in samples having low indium doping levels (2×1014/cm3). The CdTe passivation layers were generally columnar and polycrystalline, and interfaces with the p-type HgCdTe layers were
uneven. No obvious structural changes were apparent in the region of the CdTe/HgCdTe interfaces as a result of annealing at
250°C. 相似文献
93.
Steve Torrance 《人工智能实验与理论杂志》2013,25(3):353-376
Those who support a computationalist view of the mind tend to hold that it must apply to all aspects of mentality. This view is called computational universalism. An apparently opposed perception-phenomenal universalism-is that consciousness is at the root of all mental processes. Computationalists tend to cognitivize, or otherwise play down, phenomenal consciousness. The recent book by David Chalmers proposes one way to take both computation and phenomenal consciousness seriously. A different way is explored here, which avoids the commitment to a non-materialist ontology of consciousness in Chalmers' position. This alternative approach rejects universalism of both the computational and the phenomenal kinds. Instead a pluralistic view of mind is proposed. Cognitive and phenomenal aspects of mind are to be taken as equally fundamental and as complementary. Cognitive or productive aspects of mind have their own kind of reality which is independent of consciousness. Semantic content may well result from the combination of cognitive productivity and consciousness. The view proposed offers solutions to old problems affecting computational accounts. 相似文献
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A new research frontier for evolutionary 2D image generation is the use of mathematical models of aesthetics, with the goal of automatically evolving aesthetically pleasing images. This paper investigates the application of similar models of aesthetics towards the evolution of 3-dimensional structures. We extend existing models of aesthetics used for image evaluation to the 3D realm, by considering quantifiable properties of surface geometry. Analyses used include entropy, complexity, deviation from normality, 1/f noise, and symmetry. A new 3D L-system implementation promotes accurate analyses of surface features, as well as productive rule sets when used with genetic programming. Multi-objective evaluation reconciles multiple aesthetic criteria. Experiments resulted in the generation of many models that satisfied multiple criteria. A human survey was conducted, and survey takers showed a statistically significant preference for high-fitness highly-evolved models over low-fitness unevolved ones. This research shows that aesthetic evolution of 3D structures is a promising new research area for evolutionary design. 相似文献
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Charles Parker 《Knowledge and Information Systems》2013,35(1):131-152
If one is given two binary classifiers and a set of test data, it should be straightforward to determine which of the two classifiers is the superior. Recent work, however, has called into question many of the methods heretofore accepted as standard for this task. In this paper, we analyze seven ways of determining whether one classifier is better than another, given the same test data. Five of these are long established, and two are relative newcomers. We review and extend work showing that one of these methods is clearly inappropriate and then conduct an empirical analysis with a large number of datasets to evaluate the real-world implications of our theoretical analysis. Both our empirical and theoretical results converge strongly toward one of the newer methods. 相似文献
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