An Ensemble-based approach for assigning text to correct Harmonized system code

Industries must follow government rules and regulations around the world to classify products when assessing duties and taxes for international shipment. Harmonized System (HS) is the most standardized numerical method of classifying traded products among industry classification systems. A hierarchical ensemble model comprising of Bert-transformer, NER, distance-based approaches, and knowledge-graphs have been developed to address scalability, coverage, ability to capture nuances, automation and auditing requirements when classifying unknown text-descriptions as per HS method

Covariance matrices for the Lyman-α\alpha forest using the lognormal approximation

We investigate the nature of correlations in the small-scale flux statistics of the Lyman-$\alpha$ (Ly$\alpha$) forest across redshift bins. Understanding these correlations is important for unbiased cosmological and astrophysical parameter inference using the Ly$\alpha$ forest. We focus on the 1-dimensional flux power spectrum (FPS) and mean flux ($\bar F$) simulated using the semi-numerical lognormal model we developed in earlier work. The lognormal model can capture the effects of long wavelength modes with relative ease as compared to full smoothed particle hydrodynamical (SPH) simulations that are limited by box volume. For a single redshift bin of size $\Delta z\simeq 0.1$, we show that the lognormal model predicts positive cross-correlations between $k$-bins in the FPS, and a negative correlation for $\bar F\times$ FPS, in qualitative agreement with SPH simulations and theoretical expectations. For measurements across two neighbouring redshift bins of width $\Delta z$ each (obtained by 'splitting' skewers of length $2\Delta z$ in half), the lognormal model predicts an anti-correlation for FPS $\times$ FPS and a positive correlation for $\bar F\times$ FPS, caused by long wavelength modes. This is in contrast to SPH simulations which predict a negligible magnitude for cross-redshift correlations derived from such `split' skewers, and we discuss possible reasons for this difference. Finally, we perform a preliminary test of the impact of neglecting long wavelength modes on parameter inference, finding that whereas the correlation structure of neighbouring redshift bins has relatively little impact, the absence of long wavelength modes in the model can lead to $\gtrsim2-\sigma$ biases in the inference of astrophysical parameters. Our results motivate a more careful treatment of long wavelength modes in analyses that rely on the small scale Ly$\alpha$ forest for parameter inference.Comment: 17 pages, 6 figures, to be submitted to JCA

A modified lognormal approximation of the Lyman-α\alpha forest: comparison with full hydrodynamic simulations at 2≤z≤2.72\leq z\leq 2.7

Observations of the Lyman-$\alpha$ forest in distant quasar spectra with upcoming surveys are expected to provide significantly larger and higher-quality datasets. To interpret these datasets, it is imperative to develop efficient simulations. One such approach is based on the assumption that baryonic densities in the intergalactic medium (IGM) follow a lognormal distribution. We extend our earlier work to assess the robustness of the lognormal model of the Lyman-$\alpha$ forest in recovering the parameters characterizing IGM state, namely, the mean-density IGM temperature ($T_0$), the slope of the temperature-density relation ($\gamma$), and the hydrogen photoionization rate ($\Gamma_{12}$), by comparing with high-resolution Sherwood SPH simulations across the redshift range $2 \leq z \leq 2.7$. These parameters are estimated through a Markov Chain Monte Carlo technique, using the mean and power spectrum of the transmitted flux. We find that the usual lognormal distribution of IGM densities cannot recover the parameters of the SPH simulations. This limitation arises from the fact that the SPH baryonic density distribution cannot be described by a simple lognormal form. To address this, we extend the model by scaling the linear density contrast by a parameter $\nu$. While the resulting baryonic density is still lognormal, the additional parameter gives us extra freedom in setting the variance of density fluctuations. With this extension, values of $T_0$ and $\gamma$ implied in the SPH simulations are recovered at $\sim 1-\sigma$ ($\lesssim$ 10%) of the median (best-fit) values for most redshifts bins. However, this extended lognormal model cannot recover $\Gamma_{12}$ reliably, with the best-fit value discrepant by $\gtrsim 3-\sigma$ for $z > 2.2$. Despite this limitation in the recovery of $\Gamma_{12}$, we argue that the model remains useful for constraining cosmological parameters.Comment: 17 pages, 8 figure

Controlling Environmental Pollution, Sectoral Composition and Factor Prices: A H-O and SFM Hybrid Approach

The consternation regarding environment is manifold. One of them is environmental quality which has both short-run and long-run implications including sustainable development goals. In view of such apprehension, this paper develops a Heckscher-Ohlin nugget kind of competitive general equilibrium model with four sectors and four factors of production to analyse the effect of tax policy to curb environmental pollution. Surprisingly we find that environmental tax on the polluting sector eventually raises the production of polluting output and widens the wage inequality between skilled and unskilled labour. On the other hand, taxing the non-polluting sector yields the desired outcome in both production and factor income. The possibility of vanishing sector strengthens the counterintuitive results we get in case of taxing the non-polluting sector. Such an intriguing outcome is driven by the recursive nature of structure of the H-O nugget model

Controlling Environmental Pollution, Sectoral Composition and Factor Prices: A H-O and SFM Hybrid Approach

The consternation regarding environment is manifold. One of them is environmental quality which has both short-run and long-run implications including sustainable development goals. In view of such apprehension, this paper develops a Heckscher-Ohlin nugget kind of competitive general equilibrium model with four sectors and four factors of production to analyse the effect of tax policy to curb environmental pollution. Surprisingly we find that environmental tax on the polluting sector eventually raises the production of polluting output and widens the wage inequality between skilled and unskilled labour. On the other hand, taxing the non-polluting sector yields the desired outcome in both production and factor income. The possibility of vanishing sector strengthens the counterintuitive results we get in case of taxing the non-polluting sector. Such an intriguing outcome is driven by the recursive nature of structure of the H-O nugget model. We empirically test the efficacy of environmental taxes using panel data of 10 OECD countries for 1997-2020 and find that environmental taxes have a deleterious effect on pollution

Preliminary study on antiulcer effect of agomelatine and its potentiation with pyridoxine

Background: Agomelatine is a synthetic analogue of melatonin and a potent agonist of melatonin receptors. Agomelatine has Hepatoprotective as well as antioxidant activity. The aim of study was to evaluate the antiulcer activity of Agomelatine and its potentiation through the pyridoxine on ethanol induced gastric ulcer in rats.Methods: Thirty number of rats were divided in to five groups contro, standard, Agomelatine low dose, Agomelatine high dose and Agomelatine with Pyridoxine groups. Ethanol was used to induced gastric ulcer in rats. ulcer index and also the other biochemical parameters like free Acidity, total Acidity, gastric pH, volume of gastric juice was determined. Statistically analysis was done by ANOVA P value less than 0.05 was considered Statistically significant.Results: In the present study, an attempt has been made to investigate the gastric antisecretory, antiulcer and cytoprotective properties of agomelatine. The results are statistically significant by ANOVA test. Ranitidine showed a statistically significant decrease in the volume of gastric juice by free acidity and total acidity. when compared to control. Agomelatine shows a showed similar response to the volume of gastric juice. A significant difference in pH was observed between the agomelatine-treated, agomelatine with pyridoxine treated group and the control groups.Conclusions: Pretreated rats with Agomelatine (40mg/kg) showed protective effect against ethanol induce gastric ulcer. Agomelatine (40mg/kg) showed the ameliorative effect with Pyridoxine (0.3mg/kg), on gastric ulcer