Generalized Zero-Shot Learning via Synthesized Examples

We present a generative framework for generalized zero-shot learning where the training and test classes are not necessarily disjoint. Built upon a variational autoencoder based architecture, consisting of a probabilistic encoder and a probabilistic conditional decoder, our model can generate novel exemplars from seen/unseen classes, given their respective class attributes. These exemplars can subsequently be used to train any off-the-shelf classification model. One of the key aspects of our encoder-decoder architecture is a feedback-driven mechanism in which a discriminator (a multivariate regressor) learns to map the generated exemplars to the corresponding class attribute vectors, leading to an improved generator. Our model's ability to generate and leverage examples from unseen classes to train the classification model naturally helps to mitigate the bias towards predicting seen classes in generalized zero-shot learning settings. Through a comprehensive set of experiments, we show that our model outperforms several state-of-the-art methods, on several benchmark datasets, for both standard as well as generalized zero-shot learning.Comment: Accepted in CVPR'1

BROADBAND MICROWAVE SPECTROSCOPY OF TRANS 3-PENTENENITRILE AND ITS PYROLYSIS PRODUCTS

Titan, a moon of Saturn, has an atmosphere that is similar to prebiotic earth, which is nitrogen rich. Pentenenitriles are of importance as they are potential precursors to hetro-aromatic compounds like pyridine. This talk will describe our broadband microwave studies of \textit{trans} 3-pentenenitrile (\textit{t}-3PN) under jet-cooled conditions. Strong-field coherence breaking (SFCB) was used to selectively modulate the intensities of microwave transitions in a conformer-specific manner, aiding analysis. Two conformers of \textit{t}-3PN were identified and the rotational transitions were assigned. The talk will compare the conformational preferences of 3-pentenenitrile with its isomer, 4-pentenenitrile, previously studied in our laboratory. The studies of \textit{t}-3PN serve as a necessary foundation for subsequent studies of its pyrolysis over the 300K-850K temperature range, using a modified Chen nozzle followed by supersonic expansion. We combined CP-FTMW instrument with vacuum ultraviolet (VUV) time-of-flight mass spectrometry (TOF-MS) to obtain mass-correlated broadband microwave spectra. The temperature dependence of the mass spectra aid in identifying the carriers of new transitions appearing in the microwave spectrum. The thermal decomposition of t-3PN produces a range of products, including those that are both radical and molecular in nature

PROPYLBENZENE-(H2O)n CLUSTERS: EFFECT OF THE ALKYL CHAIN ON THE π H-BOND

This talk focuses on the mass resolved- resonant 2-photon ionization (R2PI), resonant ion-dip infrared spectroscopy (RIDIR) and IR-UV holeburning (IR-UV HB) spectroscopy of propylbenzene(pBz)-(\chem{H_2O})$_{n}$ clusters and the comparison with their Benzene(Bz)-(\chem{H_2O})$_{n}$ cluster counterparts, which are a well-studied prototype system for the $\pi$ H-bond. Since the pBz monomer exists in \textit{gauche} and \textit{trans} conformers, one anticipates the presence of pBz-\chem{H_2O} complexes with \chem{H_2O} on the same or opposite sides of the ring as the \textit{gauche} or \textit{trans} propyl chain. Indeed, local minima associated with these four complexes were identified by dispersion-corrected DFT calculations. R2PI and IR-UV HB spectra of pBz-\chem{H_2O} show long Franck-Condon progressions associated with the set of conformers of the complex. The OH stretch RIDIR spectra consist of a single transition in the symmetric stretch region, and a doublet with varying spacing in the antisymmetric stretch region, indicating coupling to a large-amplitude motion (LAM). The changes in the OH stretch region indicate that the water molecule bound to propylbenzene undergoes more restricted motion on the $\pi$ cloud than its Bz-\chem{H_2O} counterpart. The potential energy surface for \chem{H_2O} tumbling on the pBz $\pi$ cloud was mapped out, and used as the basis for calculating from first principles the OH stretch infrared spectrum. Comparison with the spectrum for Bz-\chem{H_2O} further illustrates the source and restrictions of the LAM of \chem{H_2O} in pBz compared to Bz. OH stretch IR spectra of the higher water clusters pBz-(\chem{H_2O})$_{n}$ with n=3, 4 are very similar to their Bz-(\chem{H_2O})$_{n}$ counterparts, existing as H-bonded cycles, with no evidence of LAM on the aromatic $\pi$ cloud

CONFORMATIONAL EXPLOSION: UNDERSTANDING THE COMPLEXITY OF THE PARA-DIALKYLBENZENE POTENTIAL ENERGY SURFACES

This talk focuses on the single-conformation spectroscopy of small-chain para-dialkylbenzenes. This work builds on previous studies from our group on long-chain n-alkylbenzenes that identified the first folded structure in octylbenzene. The dialkylbenzenes are representative of a class of molecules that are common components of coal and aviation fuel and are known to be present in vehicle exhaust. We bring the molecules para-diethylbenzene, para-dipropylbenzene and para-dibutylbenzene into the gas phase and cool the molecules in a supersonic expansion. The jet-cooled molecules are then interrogated using laser-induced fluorescence excitation, fluorescence dip IR spectroscopy (FDIRS) and dispersed fluorescence. The LIF spectra in the S$_{0}$-S$_{1}$ origin region show dramatic increases in the number of resolved transitions with increasing length of alkyl chains, reflecting an explosion in the number of unique low-energy conformations formed when two independent alkyl chains are present. Since the barriers to isomerization of the alkyl chain are similar in size, this results in an 'egg carton' shape to the potential energy surface. We use a combination of electronic frequency shift and alkyl CH stretch infrared spectra to generate a consistent set of conformational assignments

A Defected Ground Structure Based Compact Circular Patch Antenna Design for mm Wave Application

This paper presents a novel defected ground structure-based slotted circular patch antenna for mm-Wave application. A circular patch antenna with a compact size of 10 mm×8 mm×0.75 mm is fabricated in the lab. The designed antenna has a 2 GHz impedance bandwidth that covers the frequency range of 42GHz to 44GHz. It achieves a directional radiation pattern for millimeter-wave applications and has a maximum realized gain of 6 dBi at the operating frequency of 42.65 GHz. Defected ground structure (DGS) is loaded on the bottom of the dielectric substrate, which improves the gain and reduces the surface wave propagation. The proposed antenna has achieved circular polarization which makes it suitable for the mm-Wave application

Chemical Biology Strategies to Study Autophagy

Growing amount of evidence in the last two decades highlight that macroautophagy (generally referred to as autophagy) is not only indispensable for survival in yeast but also equally important to maintain cellular quality control in higher eukaryotes as well. Importantly, dysfunctional autophagy has been explicitly shown to be involved in various physiological and pathological conditions such as cell death, cancer, neurodegenerative, and other diseases. Therefore, modulation and regulation of the autophagy pathway has emerged as an alternative strategy for the treatment of various disease conditions in the recent years. Several studies have shown genetic or pharmacological modulation of autophagy to be effective in treating cancer, clearing intracellular aggregates and pathogens. Understanding and controlling the autophagic flux, either through a genetic or pharmacological approach is therefore a highly promising approach and of great scientific interest as spatiotemporal and cell-tissue-organ level autophagy regulation is not clearly understood. Indeed, chemical biology approaches that identify small molecule effectors of autophagy have thus a dual benefit: the modulators act as tools to study and understand the process of autophagy, and may also have therapeutic potential. In this review, we discuss different strategies that have appeared to screen and identify potent small molecule modulators of autophagy

A Novel Clustering Algorithm to Capture Utility Information in Transactional Data

We develop and design a novel clustering algorithm to capture utility information in transactional data. Transactional data is a special type of categorical data where transactions can be of varying length. A key objective for all categorical data analysis is pattern recognition. Therefore, transactional clustering algorithms focus on capturing the information on high frequency patterns from the data in the clusters. In recent times, utility information for category types in the data has been added to the transactional data model for a more realistic representation of data. As a result, the key information of interest has become high utility patterns instead of high frequency patterns. To the best our knowledge, no existing clustering algorithm for transactional data captures the utility information in the clusters found. Along with our new clustering rationale we also develop corresponding metrics for evaluating quality of clusters found. Experiments on real datasets show that the clusters found by our algorithm successfully capture the high utility patterns in the data. Comparative experiments with other clustering algorithms further illustrate the effectiveness of our algorithm