COTA: Improving the Speed and Accuracy of Customer Support through Ranking and Deep Networks

For a company looking to provide delightful user experiences, it is of paramount importance to take care of any customer issues. This paper proposes COTA, a system to improve speed and reliability of customer support for end users through automated ticket classification and answers selection for support representatives. Two machine learning and natural language processing techniques are demonstrated: one relying on feature engineering (COTA v1) and the other exploiting raw signals through deep learning architectures (COTA v2). COTA v1 employs a new approach that converts the multi-classification task into a ranking problem, demonstrating significantly better performance in the case of thousands of classes. For COTA v2, we propose an Encoder-Combiner-Decoder, a novel deep learning architecture that allows for heterogeneous input and output feature types and injection of prior knowledge through network architecture choices. This paper compares these models and their variants on the task of ticket classification and answer selection, showing model COTA v2 outperforms COTA v1, and analyzes their inner workings and shortcomings. Finally, an A/B test is conducted in a production setting validating the real-world impact of COTA in reducing issue resolution time by 10 percent without reducing customer satisfaction

Lone Star imPRESSions: A History of Small Press in Texas

Welcome. I believe that small press publishing is a force in Texas, and this exhibit is my way of honoring that. There have been so many different small presses to exist throughout Texas history that I could spend years collecting that information. So I decided to create an exhibit that highlights some of the oldies and some of the new players on the block. The exhibit is not a comprehensive history, but its a window into a history that is diverse and rich. If you are looking to read further on small press, check out my exhibit catalog at guides.lib.utexas.edu/utpc/currentexhibit. I have taken the liberty of providing additional details about each press, adding some others that couldn’t quite fit the exhibit, and providing submission details on each press for those of you looking to publish. I hope you enjoy the exhibit. Welcome to the hard work and perseverance that is Texas small press!UT Librarie

Classifying Voronoi graphs of hex spheres

A hex sphere is a singular Euclidean sphere with four cones points whose cone angles are (integer) multiples of 2*pi/3 but less than 2*pi. Given a hex sphere M, we consider its Voronoi decomposition centered at the two cone points with greatest cone angles. In this paper we use elementary Euclidean geometry to describe the Voronoi regions of hex spheres and classify the Voronoi graphs of hex spheres (up to graph isomorphism).Comment: 14 pages, 9 figure

Cota 823.00

Postprint (published version

Protein engineering of cota laccase by using bacillus subtilis spore display

Spore display offers advantages over more commonly utilized microbe cell-surface display systems. For instance, protein-folding problems associated with the expressed recombinant polypeptide crossing membranes are avoided. Hence, a different region of protein space can be explored that previously was not accessible. In addition, spores tolerate many physical/chemical extremes. The aim is to improve pH stability using spore display. The maximum activity of CotA is between pH 4 and 5 for the substrate ABTS (ABTS = diammonium 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate)). However, the activity dramatically decreases at pH 4. The activity is not significantly altered at pH 5. CotA is used as a model to prove that enzymes could be improved for pH resistance by using Bacillus subtilis spore display. First, CotA is evolved for increased half-life (t1/2) at pH 4. Next, a double mutant is constructed. This variant combines the amino acid substitutions from the improved t1/2 variant (E498G) and organic solvent tolerant mutant (T480A). The t1/2 and kinetic parameters are evaluated for the double mutant. Consequently, T480A/E498G-CotA is constructed and the t1/2 is 62.1 times greater than wt-CotA. Finally, T480A/E498G-CotA yields 5.3-fold more product than does wt-CotA after recycling the biocatalyst seven times over 42 h. Also, the mutant and wild-type are overexpressed in E. coli and purified. The enzymes immobilized in the spore coat are compared with the purified free protein. The t1/2 and catalytic efficiency follow the same trends for spore or E. coli expressed wt-CotA and E498G-CotA, although the kinetic parameters are different. In a previous investigation, a laccase (CotA), which is found on the spore coat of Bacillus subtilis, was engineered by directed evolution for improved activity in organic solvents. A CotA variant was identified with a Thr480Ala (T480A-CotA) amino acid substitution after only one round of evolution. The screen was performed at 60 % DMSO and it was 2.38-fold more active than the wild-type CotA (wt-CotA) with substrate ABTS. T480A-CotA was more active from a range of 0 - 70 % DMSO. In addition, the variant was more active in ethanol, methanol and acetonitrile. In this study, the catalysis of T480A-CotA and wt-CotA in the spore coat is determined with natural phenolic compounds, such as (+)-catechin, (-)-epicatechin and sinapic acid in aqueous-organic media. In general, the catalytic efficiency (Vmax/Km (δA/OD580)/mM) of T480A-CotA is higher than wt-CotA for all the substrates. Then, the Vmax for T480A-CotA is greater than the wt-CotA in all organic solvents used in this study. The Vmax for T480A-CotA is up to 3.4-fold, 7.9-fold and 6.4-fold greater than wt-CotA for substrate (+)-catechin, (-)-epicatechin and sinapic acid, respectively. In addition, the catalyst can be easily removed from the reaction solution and reused. This allows for simpler recovery of the product from the enzyme. This investigation indicates that enzymes expressed on the spore coat can be utilized for industrial applications

Using EEG and NIRS for brain-computer interface and cognitive performance measures: a pilot study

This study addresses two important problem statements, namely, selection of training datasets for online Brain-Computer Interface (BCI) classifier training and determination of participant concentration levels during an experiment. The work also attempted a pilot study to integrate electroencephalograms (EEGs) and Near Infra Red Spectroscopy (NIRS) for possible applications such as the BCI and for measuring cognitive levels. Two experiments are presented, the first being a mathematical task interleaved with rest states using NIRS only. In the next, integration of the EEG-NIRS with reference to P300-based BCI systems as well as the experimental conditions designed to elicit the concentration levels (denoted as ON and OFF states here) during the paradigm, are presented. The first experiment indicates that NIRS can be used to differentiate a concentrated (i.e., mental activity) level from the rest. However, the second experiment reveals statistically significant results using the EEG only. We present details about the equipment used, the participants as well as the signal processing and machine learning techniques implemented to analyse the EEG and NIRS data. After discussing the results, we conclude by describing the research scope as well as the possible pitfalls in this work from a NIRS viewpoint, which presents an opportunity for future research exploration for BCI and cognitive performance measures

Optimized Gillespie algorithms for the simulation of Markovian epidemic processes on large and heterogeneous networks

Numerical simulation of continuous-time Markovian processes is an essential and widely applied tool in the investigation of epidemic spreading on complex networks. Due to the high heterogeneity of the connectivity structure through which epidemics is transmitted, efficient and accurate implementations of generic epidemic processes are not trivial and deviations from statistically exact prescriptions can lead to uncontrolled biases. Based on the Gillespie algorithm (GA), in which only steps that change the state are considered, we develop numerical recipes and describe their computer implementations for statistically exact and computationally efficient simulations of generic Markovian epidemic processes aiming at highly heterogeneous and large networks. The central point of the recipes investigated here is to include phantom processes, that do not change the states but do count for time increments. We compare the efficiencies for the susceptible-infected-susceptible, contact process and susceptible-infected-recovered models, that are particular cases of a generic model considered here. We numerically confirm that the simulation outcomes of the optimized algorithms are statistically indistinguishable from the original GA and can be several orders of magnitude more efficient.Comment: 12 pages, 9 figure

The impact of fiscal policy on government bond spreads in emerging markets

Spreads on government bonds are a collective expression of differences in the level of development, risk, expected returns and other essential characteristics of states or regions the bond yields of which we wish to compare. At issue here is a collective expression of factors that work on the bond supply and demand side. These are for example the political environment (or political risks), expected return, economic risks, expected inflation, expected change in the exchange rate, solvency, way in which the bonds of a given state fit into the portfolios of the major investors and so on. The paper identifies the influence of fiscal and non-fiscal factors on movements in spreads on government bonds in emerging markets. The possibility of isolating fiscal from non-fiscal influences on spreads and the identification of the nature of fiscal impacts can be of great importance for the conduct of fiscal policy. The results obtained can be used for an optimisation of fiscal policy so as to avoid negative impacts on yields (i.e. a growth in yields), that is, a growth in the costs of government borrowing. This paper enlarges the line of research by querying whether the structure of deficit financing (domestic or foreign) has an impact on bond yields in emerging markets, and how this impact is reflected on the other determinants of fiscal policy.fiscal policy, spreads, public debt, foreign debt, public finance, financial crisis, budgetary deficit