A Python-based Mixed Discrete-Continuous Simulation Framework for Digital Twins

The use of Digital Twins is set to transform the manufacturing sector by aiding monitoring and real-time decision making. For several applications in this sector, the system to be modeled consists of a mix of discrete-event and continuous processes interacting with each other. Building simulation-based Digital Twins of such systems necessitates an open, flexible simulation framework which can support easy modeling and fast simulation of both continuous and discrete-event components, and their interactions. In this paper, we present an outline and key design aspects of a Python-based framework for performing mixed discrete-continuous simulations. The continuous processes in the system are assumed to be loosely coupled to other components via pre-defined events. For example, a continuous state variable crossing a threshold may trigger an external event. Similarly, external events may lead to a sudden change in the trajectory, state value or boundary conditions in a continuous process. We first present a systematic events-based interface using which such interactions can be modeled and simulated. We then discuss implementation details of the framework along with a detailed example. In our implementation, the advancement of time is controlled and performed using the event-stepped engine of SimPy (a popular discrete-event simulation library in Python). The continuous processes are modelled using existing frameworks with a Python wrapper providing the events interface. We discuss possible improvements to the time advancement scheme, a roadmap and use cases for the framework.Comment: Under review for publication in Springer Lecture Notes in Networks and Systems (LNNS

Regulation of miR394 in Response to Fusarium oxysporum f. sp. cepae (FOC) Infection in Garlic (Allium sativum L)

MicroRNAs (miRNAs) are a class of post transcriptional regulators that negatively regulate gene expression through target mRNA cleavage or translational inhibition and play important roles in plant development and stress response. In the present study, 6 conserved miRNAs from garlic (Allium sativum L.) were analysed to identify differentially expressed miRNAs in response to Fusarium oxysporum f. sp. cepae (FOC) infection. Stem-loop RT-PCR revealed that miR394 is significantly induced in garlic seedlings post treatment with FOC for 72 h. The induction of miR394 expression during FOC infection was restricted to the basal stem plate tissue, the primary site of infection. Garlic miR394 was also upregulated by exogenous application of jasmonic acid. Two putative targets of miR394 encoding F-box domain and cytochrome P450 (CYP450) family proteins were predicted and verified using 5’ RLM-RACE (RNA ligase mediated rapid amplification of cDNA ends) assay. Quantitative RT-PCR showed that the transcript levels of the predicted targets were significantly reduced in garlic plants exposed to FOC. When garlic cultivars with variable sensitivity to FOC were exposed to the pathogen, an upregulation of miR394 and down regulation of the targets were observed in both varieties. However, the expression pattern was delayed in the resistant genotypes. These results suggest that miR394 functions in negative modulation of FOC resistance and the difference in timing and levels of expression in variable genotypes could be examined as markers for selection of FOC resistant garlic cultivars

Parameter sensitivity for wave breaking closures in Boussinesq-type models

We consider the issue of wave-breaking closure for the well known Green-Naghdi model and attempt at providing some more understanding of the sensitivity of some closure approaches to the numerical setup. More precisely and based on we used two closure strategies for modelling wave-breaking of a solitary wave over a slope. The first one is the hybrid method consisting of suppressing the dispersive terms in a breaking region and the second one is an eddy viscosity approach based on the solution of a turbulent kinetic energy model. The two closures use the same conditions for the triggering of the breaking mechanisms. Both the triggering conditions and the breaking models themselves use case depended / ad/hoc parameters which are affecting the numerical solution wile changing. The scope of this work is to make use of sensitivity indices computed by means of Analysis of Variance (ANOVA) to provide the sensitivity of wave breaking simulation to the variation of parameters such as the mesh size and the breaking parameters specific to each breaking model. The sensitivity analysis is performed using the UQlab framework for Uncertainty Quantification

Sensitivity analysis for two wave breaking models used by the Green-Naghdi equation

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Nanotechnological innovation for the production of daughter less Tilapia, Oreochromis niloticus (Linnaeus, 1758)

The aim of present work was to develop a new Fadrozole (FDZ)-loaded Poly (D,L-lactide-co– glycolide) lactide:glycolide (50:50)(PLGA) nanoparticles for effective delivery of the masculinization drug, Fadrozole, as an alternative to commercially available masculinization agents like testosterone (dietary supplementation of 17 ?- methyltestosterone) which are steroids and banned in most EU countries. The FDZ-loaded PLGA NPs were pre-pared by solvent displacement technique. The particle size of FDZ-loaded PLGA NPs was analyzed using LICOMP particle size analyser. It was found to be in the range of 60±66.7 nm to 560±66.7 nm with average size of 201.4±66.7 nm, where the Zeta potential was estimated to be about -20.82 mV, a series of experiments were carried out to induce masculinization using FDZ-loaded PLGA nanoparticles during the sex differentiation period. Tilapia, Oreochromis niloticus fry were treated with FTZ-loaded PLGA nanoparticles at dosages 5, 25, 50 and 100ppm/kg diet for 10, 15 and 30 days. The results indicated an increase in the proportion of males with dosage and duration of treatment. The male percentage was 92.35±0.86 for T7(50 ppm) at 10 days, 97.76±1.12 for T7 (100 ppm) at 15 days and 100 % for both T6 (50ppm) and T7 (100 ppm) at 30 days. This is first time done by using nanotechnology efficiently in Tilapia species which is very important Fresh water aquaculture species in present era. Which showed increase the male population with lesser dose of nano-encapsulated Fadrozole (FDZ) loaded PLGA nanoparticles drug as compared with naked control Fadrozole (FDZ) drug delivery