Parameter estimation of bilinear systems based on an adaptive particle swarm optimization

Bilinear models can approximate a large class of nonlinear systems adequately and usually with considerable parsimony in the number of coefficients required. This paper presents the application of Particle Swarm Optimization (PSO) algorithm to solve both offline and online parameter estimation problem for bilinear systems. First, an Adaptive Particle Swarm Optimization (APSO) is proposed to increase the convergence speed and accuracy of the basic particle swarm optimization to save tremendous computation time. An illustrative example for the modeling of bilinear systems is provided to confirm the validity, as compared with the Genetic Algorithm (GA), Linearly Decreasing Inertia Weight PSO (LDW-PSO), Nonlinear Inertia Weight PSO (NDW-PSO) and Dynamic Inertia Weight PSO (DIW-PSO) in terms of parameter accuracy and convergence speed. Second, APSO is also improved to detect and determine varying parameters. In this case, a sentry particle is introduced to detect any changes in system parameters. Simulation results confirm that the proposed algorithm is a good promising particle swarm optimization algorithm for online parameter estimation.     

Broiler chicken litter application timing effect on Coastal bermudagrass in southeastern U.S.

Presently, more than 85% of the broiler chicken (Gallus gallus domesticus) litter (BCL) is being applied to pasture lands year-round. This practice results in nutrient losses and potentially unfavorable environmental impacts particularly during the wet winter months. A field plot experiment was initiated in 2001 on a Ruston silt loam in Mize, MS to identify the proper BCL application timing that enhances BCL nutrient uptake by crops while minimizing undesirable nutrient buildup in soil. Seven treatments (BCL application timings) were employed on previously established “Coastal” hybrid bermudagrass [Cynodon dactylon (L.) Pers.] plots. For each treatment, the quantity of broiler chicken litter (a mixture of chicken manure plus bedding materials) needed for each plot was calculated based on the BCL total N content to provide 400 kg N ha⁻¹ for top bermudagrass yield (18 Mg ha⁻¹) and applied either as a single, two-way split, or three-way split at different dates as follow: May; May/June; April/May/June; May/June/July; June/July/August; July/August/September; and August/September/October. Bermudagrass was harvested 5 times each year for dry matter (DM) and nutrient uptake determination. Significant differences in DM yield were observed in each year among application timings. The greatest DM yield was 18.6 Mg ha⁻¹ for the single application in May and lowest at 15.0 Mg ha⁻¹ for Aug/Sep/Oct application dates in 2001 and followed by the same trend in 2002. The N and P uptake by bermudagrass ranged from 270 to 381, and 53 to 63 kg ha⁻¹ respectively, in 2001. Similar trend, but lower values for nutrient uptake were observed in 2002. Significant differences were observed among BCL application timings in regard to soil residual of total carbon (TC), total nitogen (TN), Mehlich 3 extracted P (M3-P), NO₃–N, Cu, and Fe elements at the end of the study. In general, summer and early fall BCL applications resulted in greater buildup of most of these elements. Based on the results of this study, there is a wide window (May–July) for BCL application timing on bermudagrass considering the criteria of producing high yield and low soil residual nutrient. However, the best BCL application timing should be in spring (late April–June) when minimum temperatures exceed those required (24–27°C) for bermudagrass growth.     

Emerging Advances of Nanotechnology in Drug and Vaccine Delivery against Viral Associated Respiratory Infectious Diseases (VARID)

Viral-associated respiratory infectious diseases are one of the most prominent subsets of respiratory failures, known as viral respiratory infections (VRI). VRIs are proceeded by an infection caused by viruses infecting the respiratory system. For the past 100 years, viral associated respiratory epidemics have been the most common cause of infectious disease worldwide. Due to several drawbacks of the current anti-viral treatments, such as drug resistance generation and non-targeting of viral proteins, the development of novel nanotherapeutic or nano-vaccine strategies can be considered essential. Due to their specific physical and biological properties, nanoparticles hold promising opportunities for both anti-viral treatments and vaccines against viral infections. Besides the specific physiological properties of the respiratory system, there is a significant demand for utilizing nano-designs in the production of vaccines or antiviral agents for airway-localized administration. SARS-CoV-2, as an immediate example of respiratory viruses, is an enveloped, positive-sense, single-stranded RNA virus belonging to the coronaviridae family. COVID-19 can lead to acute respiratory distress syndrome, similarly to other members of the coronaviridae. Hence, reviewing the current and past emerging nanotechnology-based medications on similar respiratory viral diseases can identify pathways towards generating novel SARS-CoV-2 nanotherapeutics and/or nano-vaccines.     

A Mutation in DNA Polymerase α Rescues WEE1KO Sensitivity to HU

During DNA replication, the WEE1 kinase is responsible for safeguarding genomic integrity by phosphorylating and thus inhibiting cyclin-dependent kinases (CDKs), which are the driving force of the cell cycle. Consequentially, wee1 mutant plants fail to respond properly to problems arising during DNA replication and are hypersensitive to replication stress. Here, we report the identification of the polα-2 mutant, mutated in the catalytic subunit of DNA polymerase α, as a suppressor mutant of wee1. The mutated protein appears to be less stable, causing a loss of interaction with its subunits and resulting in a prolonged S-phase.     

Experimental and numerical study of distortion in flat,L‐shaped,and U‐shaped carbon fiber–epoxy composite parts

In this study, flat composite panels were fabricated to find the effect of different manufacturing parameters, including stacking sequence, part thickness, and tooling material, on distortion of carbon fiber‐epoxy composite parts. L‐shaped and U‐shaped panels were also made to investigate the effect of stacking sequence on spring‐in angle and warpage of the curved panels. Results showed that distortion of the flat panels caused by asymmetry in the stacking sequence was an order of magnitude greater than distortion of the panels with an unbalanced stacking sequence; whereas in the curved panels, the panel with an asymmetric stacking sequence showed the least spring‐in angle, and the largest angle was observed in the symmetric panel. MSC Marc was used to predict distortion of the panels, and the simulation results were compared with the experimental results for several stacking sequences of the flat and the L‐shaped panels. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40439.     

A Cyber-Kill-Chain based taxonomy of crypto-ransomware features

Journal of Computer Virology and Hacking Techniques - In spite of being just a few years old, ransomware is quickly becoming a serious threat to our digital infrastructures, data and services....     

Investigation of palladium-103 production and IR07-Pd brachytherapy seed preparation

In this study, design and fabrication of ¹⁰³Pd brachytherapy seed was investigated. The excitation functions of ¹⁰³Rh(p,n)¹⁰³Pd and ¹⁰³Rh(d,2n)¹⁰³Pd reactions were calculated using EMPIRE (version 3.1 Rivoli), ALICE/ASH and TALYS-1.2 codes, the TENDL-2010 database and compared with the published data. Production of ¹⁰³Pd was done via ¹⁰³Rh(p,n)¹⁰³Pd nuclear reaction. The target was bombarded with 18 MeV protons at 200 μA beam current for 15 h. After irradiation and radiochemical separation of the electroplated rhodium target, the optimum condition for absorption of ¹⁰³Pd into Amberlite®IR-93 resin was achieved at 0.5 M HCl. Version 5 of the (MCNP) Monte Carlo radiation transport code was employed to calculate the dosimetric parameters around the ¹⁰³Pd brachytherapy seed. Finally the calculated results were compared with published results for other commercial sources.     

Influence of decelerating flow on incipient motion of a gravel-bed stream

An experimental study on incipient motion of gravel-bed streams under steady-decelerating flow is presented. Experiments were carried out in a flume with two median grain sizes, d ₅₀ = 16.7 mm for a fixed-bed case and d ₅₀ = 8 mm for a mobile bed case. In addition, an effort is made to determine a simplified method for the estimation of bed shear stress in decelerating flow over fixed and mobile beds for use in field situations. From the observation of eleven fixed-bed and nine mobile-bed velocity profiles, it is revealed that the parabolic law method (PLM) and the Reynolds stress method are comparable for estimation of shear velocity in general. Also, the results show that the shear stress distribution adopts a convex form over fixed and mobile beds. Due to this form the critical Shields parameter value for decelerating flow is less than the reported values in literature. This paper supports Buffington & Montgomery (1997) statement that less emphasis should be given on choosing a universal shields parameter, and more emphasis should be given on choosing defendable values based on flow structure.