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

THE USE OF FRANCK-CONDON FACTORS FOR THE SO2 ~C-~X ELECTRONIC TRANSITION TO MEASURE VIBRATIONAL RELAXATION IN A LASER-EXCITED SUPERSONIC EXPANSION FROM AN EVEN-LAVIE VALVE

We are characterizing the vibrational relaxation dynamics of \chem{SO_2} in an Even-Lavie (EL) valve supersonic expansion. The EL valve provides rotational cooling to about 1 Kelvin with minimal clustering. In the expansion, the \~{C} $^{1}$B$_{2}$ state of \chem{SO_2} is populated using laser excitation of a selected line of the \~{C}-\~{X} electronic transition. The \~{C} state rapidly fluoresces to the \~{X} $^{1}$A$_{1}$ state with known Franck-Condon (FC) factors. \chem{SO_2} is rotationally cooled in the expansion, but vibrational cooling from the initial FC distribution is slower and depends on parameters of the supersonic expansion. Using chirped-pulse millimeter-wave spectroscopy, relative intensity measurements of selected rotational transitions and their "vibrational satellites" can be performed. The observed change of the vibrational population distribution (VPD) from that of the FC distribution describes the vibrational cooling in the EL supersonic expansion. Comparing the observed VPDs with the calculated FC intensities, we characterize the relaxation dynamics as a function of various physical parameters, including the location in the expansion and the backing pressure. This experimental scheme will also be used to characterize relaxation dynamics in a cryogenic buffer gas beam. This knowledge of the nascent (unrelaxed) VPD can be used to study the transition states of photo-fragmentation reactions

MuSeM: Detecting Incongruent News Headlines using Mutual Attentive Semantic Matching

Measuring the congruence between two texts has several useful applications, such as detecting the prevalent deceptive and misleading news headlines on the web. Many works have proposed machine learning based solutions such as text similarity between the headline and body text to detect the incongruence. Text similarity based methods fail to perform well due to different inherent challenges such as relative length mismatch between the news headline and its body content and non-overlapping vocabulary. On the other hand, more recent works that use headline guided attention to learn a headline derived contextual representation of the news body also result in convoluting overall representation due to the news body's lengthiness. This paper proposes a method that uses inter-mutual attention-based semantic matching between the original and synthetically generated headlines, which utilizes the difference between all pairs of word embeddings of words involved. The paper also investigates two more variations of our method, which use concatenation and dot-products of word embeddings of the words of original and synthetic headlines. We observe that the proposed method outperforms prior arts significantly for two publicly available datasets.Comment: Accepted paper; IEEE 2020 International Conference on Machine Learning and Applications (ICMLA

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

Indigenous Lakadong turmeric of Meghalaya and its future prospects

Turmeric (Curcuma longa) has long been used in traditional Indian medicine. India accounts for 80% of total global turmeric production. Lakadong turmeric gets its name from the tiny village of Lakadong, which is located in the foothills of the Jaintia Hills in Meghalaya, India. It is known for having a high curcumin content of more than 7%, as opposed to 2 - 4% in regular varieties. The tribes of this region brought Lakadong turmeric from the forest and domesticated it for medicinal purposes centuries ago. Growth in local coal industries and a gradual decline in the market have had a significant impact on and reduced Lakadong turmeric production. To resurrect the industry, the Meghalaya government has embarked on a mission to increase production of Lakadong turmeric to 50,000 metric tons (MT) per year by 2023, up from 20,000 MT currently. However, most farmers in this region have abandoned Lakadong turmeric cultivation due to low returns. To ensure farmers’ livelihoods, policymakers and the government must address future production challenges and create a viable market for such commodities. This review paper discusses the traditional history of Lakadong cultivation and its current status, challenges, and prospects. The paper also discusses the agronomic, phytochemical, and medicinal properties of turmeric