Publications

Deformable part models (DPMs) and convolutional neural networks (CNNs) are two widely used tools for visual recognition. They are typically viewed as distinct approaches: DPMs are graphical models (Markov random fields), while CNNs are "black-box" non-linear classifiers. In this paper, we show that a DPM can be formulated as a CNN, thus providing a synthesis of the two ideas. Our construction involves unrolling the DPM inference algorithm and mapping each step to an equivalent CNN layer. From this perspective, it is natural to replace the standard image features used in DPMs with a learned feature extractor. We call the resulting model a DeepPyramid DPM and experimentally validate it on PASCAL VOC object detection. We find that DeepPyramid DPMs significantly outperform DPMs based on histograms of oriented gradients features (HOG) and slightly outperforms a comparable version of the recently introduced R-CNN detection system, while running significantly faster.

Forty-two inpatient women with bulimia nervosa and 29 women with anorexia nervosa were surveyed regarding eating behavior, patterns of licit and illicit substance use, and relation between drug use and appetite. Substantial use of licit substances such as laxatives, diuretics, and emetics were reported in women with bulimia nervosa. In addition, alcohol and cigarette use were significantly more common in women with bulimia nervosa than anorexia nervosa. The majority of bulimic subjects reported that smoking decreased appetite, alcohol increased appetite, and laxatives had no effect on appetite. Analysis of temporal patterns of drug intake suggested that binging and purging as well as alcohol, cigarette, and laxative use were considerably more prevalent in the evening hours. We suggest that the high rates of drug use in women with bulimia nervosa may be related to effects of food deprivation associated with the disorder.

Gut gemischt! Zn1−xCoxO-Nanodrähte wurden mit einem lösungsbasierten Syntheseverfahren erhalten. Gemäß struktureller, optischer und spektroskopischer Charakterisierung ersetzen bei der Cobaltdotierung die Cobaltatome die Zinkkationen im Wirtsgitter (im Bild sind Co-dotierte ZnO-Nanodrähte zu sehen).

Though it promises high bandwidths, the optical medium is not popular in local area networks. This is because current optical networks do not offer the ease of use and setup that an uncoordinated multiple access network such as Ethernet offers. In this paper, we propose a novel nonlinear trellis code designed for multiple access among coordinated nodes in an optical communications system. This code has been shown to have an efficiency of 30%. We have implemented the codes on Xilinx FPGA's for a 6 user optical system, transmitting data on a single wavelength. The above system was set up using commercial off-the-shelf components and we demonstrated BER of < 10-0 for three users, each running at a channel rate of 2 Gbps. Demonstration of this system required the design of new channel codes, architectural optimizations for the implementation of the channel codes for high speed with limited resources and electrical/optical optimizations to realize the optical channel. © 2008 IEEE.

We have coordinated Hubble Space Telescope (HST) photometry with ground-based discovery for three supernovae: Type Ia supernovae near z~0.5 (SN 1997ce, SN 1997cj) and a third event at z=0.97 (SN 1997ck). The superb spatial resolution of HST separates each supernova from its host galaxy and leads to good precision in the light curves. We use these light curves and relations between luminosity, light-curve shape, and color calibrated from low-z samples to derive relative luminosity distances that are accurate to 10% at z~0.5 and 20% at z=1. When the HST sample is combined with the distance to SN 1995K (z=0.48), analyzed by the same precepts, we find that matter alone is insufficient to produce a flat universe. Specifically, for Ωm+ΩΛ=1, Ωm is less than 1 with more than 95% confidence, and our best estimate of Ωm is -0.1+/-0.5 if ΩΛ=0. Although this result is based on a very small sample whose systematics remain to be explored, it demonstrates the power of HST measurements for high-redshift supernovae.

The first transition metal catalyzed asymmetric carboalkoxylation reaction of propargyl esters is described. The (R)-MeO-DTBM-BIPHEP(AuCl)(2)-catalyzed reactions allow for the construction of benzopyrans containing quaternary stereocenters with excellent enantioselectivity. Experimental evidence supports a mechanism proceeding via the generation of a stabilized carbocation from an allylic oxonium intermediate and subsequent trapping by a chiral allylgold(I) spieces.