604 research outputs found
Adversarially Tuned Scene Generation
Generalization performance of trained computer vision systems that use
computer graphics (CG) generated data is not yet effective due to the concept
of 'domain-shift' between virtual and real data. Although simulated data
augmented with a few real world samples has been shown to mitigate domain shift
and improve transferability of trained models, guiding or bootstrapping the
virtual data generation with the distributions learnt from target real world
domain is desired, especially in the fields where annotating even few real
images is laborious (such as semantic labeling, and intrinsic images etc.). In
order to address this problem in an unsupervised manner, our work combines
recent advances in CG (which aims to generate stochastic scene layouts coupled
with large collections of 3D object models) and generative adversarial training
(which aims train generative models by measuring discrepancy between generated
and real data in terms of their separability in the space of a deep
discriminatively-trained classifier). Our method uses iterative estimation of
the posterior density of prior distributions for a generative graphical model.
This is done within a rejection sampling framework. Initially, we assume
uniform distributions as priors on the parameters of a scene described by a
generative graphical model. As iterations proceed the prior distributions get
updated to distributions that are closer to the (unknown) distributions of
target data. We demonstrate the utility of adversarially tuned scene generation
on two real-world benchmark datasets (CityScapes and CamVid) for traffic scene
semantic labeling with a deep convolutional net (DeepLab). We realized
performance improvements by 2.28 and 3.14 points (using the IoU metric) between
the DeepLab models trained on simulated sets prepared from the scene generation
models before and after tuning to CityScapes and CamVid respectively.Comment: 9 pages, accepted at CVPR 201
Low-Alloy High-Strength Steels
IT is significant that this symposium on alloy steels is being held in the year 1956 which marks the centenary of the birth of tonnage steel. It was exactly a hundred
years ago that Henry Bessemer heralded it new era by making it possible to produce steel for the first time in commercial tonnages. The largest proportion of steel
made and rolled today finds its way into, structural
appli-cations such as the building of bridges, transport cars, etc. Therefore structural steel occupies a promin-ent place in the eyes of the metallurgist and the engineer.
Although the manufacture of Bessemer steel was well established within a few years of its discovery, the general use of steel in building bridges and other struc-tural uses had to wait for several years. As late as
1877, a Board of Trade Regulation in England prohibited the use of mild steel in bridges. The Firth of Forth Bridge built during 1 2380-1 8 90 used for the first time steel in large quantities. The earliest use of mild
steel for bridges in U.S.A. was in the Eads Bridge over the 'Mississippi river. Since then the use of mild steel for bridges has become almost universal
Dolomite as a flux for High-Alumina Blast Furnace Slags
BLAST FURNACE operators at Jamshedpur have to face a peculiar problem arising out of the high concentration of it alumina in the slag. The normal analyses are 37.3-37.8% CaO, 3.4-3.9% MgO,30.4-31.5% SiO2, 26.2-27.0% Al2O3, 0.69-0.78% FeO and 0.69-0.82% S. The actual level, i.e. 26 to 28% is much higher than that common elsewhere and brings into force a series of adverse effects. Briefly, these consist of the greater viscosity of the alumina slags, greater tendency towards silicon reduction, and less efficient desulphurisation. As a result, it becomes rather difficult consistently to produce low-sulphur hot metal without exceeding the silicon level normally specified for basic iron
Suppressed star formation in circumnuclear regions in Seyfert galaxies
Feedback from black hole activity is widely believed to play a key role in
regulating star formation and black hole growth. A long-standing issue is the
relation between the star formation and fueling the supermassive black holes in
active galactic nuclei (AGNs). We compile a sample of 57 Seyfert galaxies to
tackle this issue. We estimate the surface densities of gas and star formation
rates in circumnuclear regions (CNRs). Comparing with the well-known
Kennicutt-Schmidt (K-S) law, we find that the star formation rates in CNRs of
most Seyfert galaxies are suppressed in this sample. Feedback is suggested to
explain the suppressed star formation rates.Comment: 1 color figure and 1 table. ApJ Letters in pres
Observations of NGC 4151 During 1970 in the Optical and Infra-red
Observations of NGC 4151 at seven wavelengths from 0.3 to 3.4 microns made during the 1970 season are presented. Variations are found at all observed wavelengths but the optical and infra-red light curves are different: an optical maximum was reached in April but the galaxy continued brightening at 2.2 μ . until the end of June. The energy distributions of the point source and the background galaxy have been separated and that of the point source Closely resembles that of the quasar 3C273. The general form of the light curves can possibly be attributed to a dust model for the infra-red emission but this would be ruled out if suspected rapid infra-red variations are confirmed
Observations of NGC 4151 During 1970 in the Optical and Infra-red
Observations of NGC 4151 at seven wavelengths from 0.3 to 3.4 microns made during the 1970 season are presented. Variations are found at all observed wavelengths but the optical and infra-red light curves are different: an optical maximum was reached in April but the galaxy continued brightening at 2.2 μ . until the end of June. The energy distributions of the point source and the background galaxy have been separated and that of the point source Closely resembles that of the quasar 3C273. The general form of the light curves can possibly be attributed to a dust model for the infra-red emission but this would be ruled out if suspected rapid infra-red variations are confirmed
Development of silicon planar P-I-N photodiode
Optical receivers are used to detect optical power and to extract the information that is being transmitted. The incident optical power is detected by a photo detector, usually a PIN or avalanche photodiode (APD). A PIN or APD is an amplitude modulation envelope photo detector, insensitive to phase or small changes in wavelength. It generates an electrical output that reproduces the envelope of the received optical signal (Li, 2000). The most widely deployed photodiode for all lightwave applications is the PIN photodiode where its performance and characteristics are well understood and documented (Campbell, 1995)
Investigation on optical interconnect(OI) link performance using external modulator
This paper investigates and analyzes an Optical Interconnect (OI) link using external (indirect) modulation technique. A Continuous Wave (CW) light source with a Mach Zehnder (MZ) modulator is used in the transmitter part and a Si-based waveguide is used as a transmission path. Indium Gallium Arsenide (InGaAs) and Germanium (Ge) materials were applied to observe the performance of Avalanche Photodiode (APD) and P-I-N Photodiode (PIN). In order to evaluate the performance of OI link using external (indirect) modulation, the model of OI link was designed and simulated using OptiSPICE tools. Simulation results on the performance of MZ modulator, power degradation of OI link and receiver sensitivity are reported in this paper
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