Harris Hawks Optimizer with Graph Convolutional Network Based Weed Detection in Precision Agriculture

Precision agriculture includes the optimum and adequate use of resources depending on several variables that govern crop yield. Precision agriculture offers a novel solution utilizing a systematic technique for current agricultural problems like balancing production and environmental concerns. Weed control has become one of the significant problems in the agricultural sector. In traditional weed control, the entire field is treated uniformly by spraying the soil, a single herbicide dose, weed, and crops in the same way. For more precise farming, robots could accomplish targeted weed treatment if they could specifically find the location of the dispensable plant and identify the weed type. This may lessen by large margin utilization of agrochemicals on agricultural fields and favour sustainable agriculture. This study presents a Harris Hawks Optimizer with Graph Convolutional Network based Weed Detection (HHOGCN-WD) technique for Precision Agriculture. The HHOGCN-WD technique mainly focuses on identifying and classifying weeds for precision agriculture. For image pre-processing, the HHOGCN-WD model utilizes a bilateral normal filter (BNF) for noise removal. In addition, coupled convolutional neural network (CCNet) model is utilized to derive a set of feature vectors. To detect and classify weed, the GCN model is utilized with the HHO algorithm as a hyperparameter optimizer to improve the detection performance. The experimental results of the HHOGCN-WD technique are investigated under the benchmark dataset. The results indicate the promising performance of the presented HHOGCN-WD model over other recent approaches, with increased accuracy of 99.13%.     

A Novel Internet of Medical Thing Cryptosystem Based on Jigsaw Transformation and Ikeda Chaotic Map

Image encryption has attracted much interest as a robust security solution for preventing unauthorized access to critical image data. Medical picture encryption is a crucial step in many cloud-based and healthcare applications. In this study, a strong cryptosystem based on a 2D chaotic map and Jigsaw transformation is presented for the encryption of medical photos in private Internet of Medical Things (IoMT) and cloud storage. A disorganized three-dimensional map is the foundation of the proposed cipher. The dispersion of pixel values and the permutation of their places in this map are accomplished using a nonlinear encoding process. The suggested cryptosystem enhances the security of the delivered medical images by performing many operations. To validate the efficiency of the recommended cryptosystem, various medical image kinds are used, each with its unique characteristics. Several measures are used to evaluate the proposed cryptosystem, which all support its robust security. The simulation results confirm the supplied cryptosystem’s secrecy. Furthermore, it provides strong robustness and suggested protection standards for cloud service applications, healthcare, and IoMT. It is seen that the proposed 3D chaotic cryptosystem obtains an average entropy of 7.9998, which is near its most excellent value of 8, and a typical NPCR value of 99.62%, which is also near its extreme value of 99.60%. Moreover, the recommended cryptosystem outperforms conventional security systems across the test assessment criteria.     

Framework for Effective Utilization of Distributed Scrum in Software Projects

There is an emerging interest in using agile methodologies in Global Software Development (GSD) to get the mutual benefits of both methods. Scrum is currently admired by many development teams as an agile most known methodology and considered adequate for collocated teams. At the same time, stakeholders in GSD are dispersed by geographical, temporal, and socio-cultural distances. Due to the controversial nature of Scrum and GSD, many significant challenges arise that might restrict the use of Scrum in GSD. We conducted a Systematic Literature Review (SLR) by following Kitchenham guidelines to identify the challenges that limit the use of Scrum in GSD and to explore the mitigation strategies adopted by practitioners to resolve the challenges. To validate our review findings, we conducted an industrial survey of 305 practitioners. The results of our study are consolidated into a research framework. The framework represents current best practices and recommendations to mitigate the identified distributed scrum challenges and is validated by five experts of distributed Scrum. Results of the expert review were found supportive, reflecting that the framework will help the stakeholders deliver sustainable products by effectively mitigating the identified challenges.     

Split internal-loop photobioreactor for Scenedesmus sp. microalgae:Culturing and hydrodynamics

In this study, the evaluation of the performance of the split internal loop photobioreactor for culturing a species of green microalgae, Scenedesmus sp. under different operating superficial gas velocity and during a different time of growth (i.e., starting for the first day until end day of the culturing process) was addressed. The evaluation of the performance of the split internal loop photobioreactor was included assessing the density, pH, temperature, vis-cosity, surface tension, the optical density, cell population, dry biomass, and chlorophyll of the culture medium of the microalgae culturing. Additionally, the hydrodynamics of a Split Internal-Loop Photobioreactor with microalgae culturing was comprehensively quantified. Radioactive particle tracking (RPT) and gamma-ray com-puted tomography (CT) techniques were applied for the first time to quantify and address the influence of microalgae culture on the hydrodynamic parameters. The hydrodynamics parameters such as local liquid veloc-ity field, shear stresses, turbulent kinetic energy, and local gas holdup profiles were measured at different super-ficial gas velocities as well as under different times of algae growth. The obtained results indicate that the flow distribution may significantly affect the performance of the photobioreactor, which may have substantial effects on the cultivation process. The obtained experimental data can serve as benchmark data for the evaluation and validation of computational fluid dynamics (CFD) codes and their closures. This, in turn, allows us to develop ef-ficient reactors and consequently improving the productivity and selectivity of these photobioreactors.     

The Effect of Furnace Parameters on Fire Severity in Standard Fire Resistance Tests

This paper discusses the predicted results obtained from models developed to determine the effects of furnace depth (2.5 m and 0.5 m), type of furnace lining material type (fireclay brick, insulating firebrick and ceramic fibre insulation) and type of fuel (gas or liquid) on fire severity in fire resistance test furnaces using the CAN/ULC-S101, ASTM E119 and ISO 834 time–temperature relationships. The type of fuel used in the furnace and the type of furnace wall lining material significantly affected the heat absorbed by the test specimen while the furnace depth effect was minimal when the furnace was lined with ceramic fibre insulation. Factors to improve the repeatability and reproducibility of the fire severity in fire resistance test furnaces are provided.     

On the positioning of revolute‐joint robot manipulators

A new technique is introduced for obtaining the sets of joint‐motor‐displacements which correspond to a desired spatial pose at the end‐effector of a revolute‐joint manipulator. The properties of rotation are exploited and a new local coordinate notation is introduced to obtain the required solution. The proposed technique leads to two simplified sets of linear equations which correspond to the kinematic behavior of both the arm and the wrist. These two sets of equations have been manipulated further to obtain polynomial solutions for both manipulator structures. © 2000 John Wiley & Sons, Inc.     

Synthesis of physically cross-linked gum Arabic-based polymer hydrogels with enhanced mechanical,load bearing and shape memory behavior

The TiO2 dispersed physically cross-linked polymer hydrogels were synthesized through a single step free radical addition polymerization mechanism based on acrylic acid and gum Arabic (GA) as polymer constituents, and ferric ions (Fe3+) as physical cross-linker. The effect of TiO2 powder was investigated on thermal and mechanical properties of the hydrogels by dispersion of 0.01, 0.02 and 0.03 g of TiO2 in hydrogels. The prepared hydrogels were successfully characterized through FTIR, XRD, SEM and thermogravimetric analysis (TGA). For the mechanical properties, dynamic mechanical analysis and universal testing machine (UTM) were used. The DMA results showed that the storage modulus was increased with the TiO2, while UTM results showed that 0.02 g of TiO2 powder significantly enhanced the fracture stress, elastic modulus, toughness and stretchability by 4514%, 4328%, 4124% and 20%, respectively, compared to the virgin hydrogels. Cole–Cole plot confirmed the homogeneity and viscoelastic behavior of the system, while manual load bearing and shape memory test showed that the hydrogels bear a load of 2.5 kg for a long time and it is recovered within 10 s to its original state. The materials can be applied for the synthesis of artificial body parts in the field of bio-engineering. The use of un-modified GA for the synthesis of hydrogels will open a new window for the researchers working in this field.     

Comparative studies on the effects of casting solvent on physico‐chemical and gas transport properties of dense polysulfone membrane used for CO2/CH4 separation

The effects of casting solvents on the physico–chemical and transport properties of polysulfone membranes were investigated. Comparative analysis of the properties of membranes prepared from a new solvent (diethylene glycol dimethyether, DEG) and other commonly used solvents (1‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, dimethyl sulfoxide and N,N‐dimethylformamide) were performed using gas permeation, X‐ray diffraction, scanning electron microscopy, thermogravimetric, and Fourier transform infrared spectroscopy analyses. The degree of polymer–solvent interaction was evaluated using the solvent molar volume, and Hansen and Flory–Huggins parameters. Membrane prepared from DEG displayed a relatively higher permeability of 29.08 barrer and CO₂/CH₄ selectivity of 23.12 compared to membranes prepared from other solvents. This improved performance was attributed to the better interaction between the DEG solvent and polysulfone than other solvents that were considered. DEG has the highest molar volume of 142.280 cm³/mol and the lowest Flory–Huggins parameter of 0.129. Thus a thorough evaluation of polymer–solvent interaction is very crucial in preparing membranes with optimum performance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42205.     

Experimental optimization of composite collapsible tubular energy absorber device

A four-phase program to improve the specific energy absorbed by axially crushed composite collapsible tubular energy absorber devices was undertaken. In the first phase, examining of the crushing behaviour of non-triggered tubes was carried out. The second phase is aimed at obtaining the best position for the triggered wall. The third phase focuses on the effects of material sizing in order to understand the influence of triggered wall length on the responses of composite circular tubes to the axial crushing load. The results of these three phases of the study contribute to the fourth whose objective is to optimize the shape geometry of the cross-section area to further improving in tube energy absorption capability. The experimental results demonstrated the strong potential benefits of optimizing the material distribution. The sizing and shape optimization of composite collapsible tubes exhibited a pronounced effect on their capability to absorb high specific energy under axial compressive load.     

Designing structures for dynamical properties via natural frequencies separation: Application to tensegrity structures design

The design of structures for dynamic properties is addressed by placing conditions on the separation between natural frequencies. Additional constraints, like lower and upper bounds on the natural frequencies, are also included. A fast numerical algorithm that exploits the mathematical structure of the resulting problem is developed. Examples of the algorithm's application to tensegrity structures design are presented and the connection between natural frequencies separation and proportional damping approximation is analyzed.