DHFormer: A Vision Transformer-Based Attention Module for Image Dehazing

Images acquired in hazy conditions have degradations induced in them. Dehazing such images is a vexed and ill-posed problem. Scores of prior-based and learning-based approaches have been proposed to mitigate the effect of haze and generate haze-free images. Many conventional methods are constrained by their lack of awareness regarding scene depth and their incapacity to capture long-range dependencies. In this paper, a method that uses residual learning and vision transformers in an attention module is proposed. It essentially comprises two networks: In the first one, the network takes the ratio of a hazy image and the approximated transmission matrix to estimate a residual map. The second network takes this residual image as input and passes it through convolution layers before superposing it on the generated feature maps. It is then passed through global context and depth-aware transformer encoders to obtain channel attention. The attention module then infers the spatial attention map before generating the final haze-free image. Experimental results, including several quantitative metrics, demonstrate the efficiency and scalability of the suggested methodology

Qualitative Analysis of Post-blast Residue using the Double Hyphenated UHPLC-(HESI)-MS/MS Technique

In this paper, the identification and forensic analysis of post-blast residues recovered from controlled blast sites has been presented. The targeted sample was extracted from post-blast soil by using the Accelerated Solvent Extraction technique. The average recovery varies from 86-93% at 250, 500,750 and 1000 ng/g concentration level. The target compound was primarily identified to be PETN (Penta Erythritol Tetra Nitrate) by a color test and TLC (Thin Layer Chromatography). The confirmatory test for the target analyte was done by using LC-MS/MS (Liquid Chromatography - Tandem Mass Spectrometry). Heated Electron Spray Ionization (HESI) interface with negative mode was employed and SRM (Selected Reaction Monitoring) on Triple Quadruple Mass Analyzer was used for confirmation of PETN in the sample. The Limit of Detection (LOD) obtained from the analysis of post-blast residue by using this method was 7.9 ng/g. This manuscript demonstrates the viability of LC-MS/MS for a fast, accurate and quality-assured analysis of post-blast residue