10 research outputs found
Detection of intra-family coronavirus genome sequences through graphical representation and artificial neural network
Abstract
In this study, chaos game representation (CGR) is introduced for investigating the pattern of genome sequences. It is an image representation of the genome for the overall visualization of the sequence. The CGR representation is a mapping technique that assigns each sequence base into the respective position in the two-dimension plane to portray the DNA sequence. Importantly, CGR provides one to one mapping to nucleotides as well as sequence. A coordinate of the CGR plane can tell the corresponding base and its location in the original genome. Therefore, the whole nucleotide sequence (until the current nucleotide) can be restored from the one point of the CGR. In this study, CGR coupled with artificial neural network (ANN) is introduced as a new way to represent the genome and to classify intra-coronavirus sequences. A hierarchy clustering study is done to validate the approach and found to be more than 90% accurate while comparing the result with the phylogenetic tree of the corresponding genomes. Interestingly, the method makes the genome sequence significantly shorter (more than 99% compressed) saving the data space while preserving the genome features
Haar wavelet based approach for short tandem repeats (STR) detection
Abstract
Short Tandem Repeats (STRs)/ Microsatellites are the key factors to find the individuality on a DNA. These are playing an essential role in forensic science. Existing tools for identifying the whole series of STRs/microsatellites necessitate a complex computational method such as fast fourier transform, pattern recognition etc. The study reflects, identifying the STR regions, involving signal processing most preferably Haar wavelet and covering the complete range of STRs in the long chain of DNA sequence. The process demands less computational complexity and time compared to the other tools
Performance of fibre-reinforced slag-based alkali activated mortar in acidic environment
Abstract
The main aim of the work is to study the effect of different fibres (steel, glass and basalt) on resistance of blast furnace slag-based alkali-activated mortar in acidic environment. The alkaliactivated slag mortars were exposed to 5% sulfuric and acetic acid solutions for 30 days. Mass change, compressive strength and microstructural changes were evaluated. In plain mortar, it was observed that 70% of the strength was retained in acetic acid environment whereas only 20% of residual strength remains in sulphuric acid environment. FTIR spectroscopy shows the degradation of the matrix, which implies the alkali-activated mortar was more vulnerable in sulphuric acid environment due to its aggressive nature compared to acetic acid. Decalcification and formation of calcium acetate also hinders the further progress of damage in acetic acid attack. Fibres helped in improving the performance of the mortar by holding the matrix together when the degradation occurred in acidic environment. Compared to plain mortar, incorporation of steel fibres exhibited a maximum strength retention of 19% in acetic acid and 7% in sulphuric acid, followed by glass and basalt fibres. SEM images clearly show the debonding of fibres and disintegration of matrix in acidic environment, which resulted in strength loss
Combined granulationâalkali activationâdirect foaming process:a novel route to porous geopolymer granules with enhanced adsorption properties
Abstract
High-value applications, such as adsorbents, have drawn attention to geopolymers. In several of those applications, having the geopolymer as porous spherical particles is beneficial. This study presents a novel process for fabricating porous metakaolin-based geopolymer granules using a combination of direct foaming, one-part alkali activation, and granulation. In short, the precursor (e.g., metakaolin) and solid activator (e.g., sodium silicate) are loaded in a granulator, in which an aqueous blowing agent (e.g., HâOâ) is added while the granulator is running, and the obtained granules are cured at 60 °C. Characterization of the granules for physico-chemical and morphological properties indicated an increase in overall porosity, especially in the ”m-scale pores. Also specific surface area (+50%) and nanoscale pore volume (+102%) increased when using more concentrated HâOâ (20 or 30%) compared to nonporous granules. The use of porous granules was also demonstrated in dynamic adsorption experiments for ammonium (NHââș) uptake, which showed up to âŒ126% increase in cumulative adsorption amount compared to nonporous granules. The highest NHââș uptake was obtained with 10% HâOâ solution as the granulation fluid. The results confirmed the feasibility of the method for introducing porosity to geopolymer granules, which enhances the adsorption properties of the granules
Authentication by mapping keystrokes to music:the melody of typing
Abstract
Expressing Keystroke Dynamics (KD) in form of sound opens new avenues to apply sound analysis techniques on KD. However this mapping is not straight-forward as varied feature space, differences in magnitudes of features and human interpretability of the music bring in complexities. We present a musical interface to KD by mapping keystroke features to music features. Music elements like melody, harmony, rhythm, pitch and tempo are varied with respect to the magnitude of their corresponding keystroke features. A pitch embedding technique makes the music discernible among users. Using the data from 30 users, who typed fixed strings multiple times on a desktop, shows that these auditory signals are distinguishable between users by both standard classifiers (SVM, Random Forests and Naive Bayes) and humans alike
On the Evolution of Collective Enforcement Institutions: Communities and Courts
Impersonal exchange has been a major driver of economic development. But transactors with no stake in maintaining an ongoing relationship have little incentive to honor deals. Therefore, all economies have developed institutions to support honest trade and realize the gains of impersonal exchange. We analyze the relative capacities of communities (or social networks) and courts to secure cooperation among heterogeneous, impersonal transactors. We find that communities and courts are complementary in the sense that they tend to support cooperation for different sets of transactions but that the existence of courts weakens the effectiveness of community enforcement. By relating the effectiveness of enforcement institutions to changes in the cost and risks of long-distance trade, driven in part by improvement in shipbuilding methods, our analysis also provides an explanation for the emergence of the medieval Law Merchant and its subsequent supersession by state courts.