Lagrangian Recurrent Steganalysis and Hyper Elliptic Certificateless Signcryption for Secure Image Transmission

Present-day evolution in communication and information technology dispenses straightforward and effortless access to data, but the most noteworthy condition is the formation of secure communication. Numerous approaches were designed for safety communication. One of the crucial approaches is image steganography. Moreover, provisioning of information security services is arrived at via cryptosystems where cryptosystems make certain the secure messages transmission between the users in an untrustworthy circumstance.  The conventional method of providing encryption and signature is said to be first signing and then encryption, but both the computation and communication costs are found to be high. A certificateless signcryption mechanism is designed to transfer the medical data or images securely. This mechanism will minimize the storage and verification costs of public key certificates. The author of this article proposes a method named Lagrangian recurrent Steganalysis and Hyper Elliptic Certificateless Signcryption for transferring the medical data or images securely. In two sections the LRS-HECS method is split. They are medical image steganalysis and certificateless signcryption. First with the Chest X-Ray images obtained as input, a Codeword Correlated Lagrangian Recurrent Neural Network-based image steganography model is applied to generate steg images. Second, to transfer the medical images securely the steg images provided as input is designed a model named a Hyper Elliptic Curve-based Certificateless Signcryption. The issue of providing the integrity and validity of the transmitted medical images and receiver anonymity is addressed by the application of Hyper Elliptic Curve. Chest X-Ray pictures were used in experimental simulations, and the findings showed that the LRS-HECS approach had more advantages over existing state-of-the-art methods in terms of higher peak signal to noise ratio with data integrity and with reduced encryption time and transmission cost

Piezoelectric actuators for delamination control in composite plates subjected to low velocity impact

The potential of MFC actuator as a tool for reducing low velocity impact induced delamination has been investigated using LS-DYNA explicit code. For this purpose, three different piezoelectric actuation models were implemented through its user defined material subroutine, namely, the linear strain model, electric field dependent model and induced strain model. The induced strain model was found to provide the best match with experimental results for actuation strain prediction, hence used in impact investigations. In predicting the delamination, a newly formulated damage model was used as it was found that the existing damage models in LS-DYNA are simplistic and rate sensitive. An independent three-dimensional piezoelectric finite element code was developed and used to study the effects of design and actuation parameters on the actuation characteristics of the MFC. The parametric study was meant to determine a laminate-actuator system that would allow sufficient presence of the piezoelectric effects in it. A selected laminate-actuator system was later used to investigate the effects of piezoelectric control actions on the impact force and displacement for purely elastic impact cases. For simply supported laminate it was found that the peak impact force and displacement could be reduced by applying a counter moment to the incoming impact load, whereas for clamped laminate the same was achieved by regulating the laminate stiffness at the impact point. The technique of impact force reduction confirmed that delamination could be reduced. However, this concept could not be experimentally verified as the design requirements could not be practically implemented. The actuator required voltages beyond its operating range to reduce delamination even in the case of very low energy impact. This is something not achievable with the existing piezoelectric materials. Assuming powerful piezoelectric actuators are not impossible in near future, this study could provide useful information for an attempt to validate this concept

Identifying and Prioritising Future Robot Control Research with Multi-Criteria Decision-Making

The gap between researchers who carry out scientific exploration and practitioners who can make use of the research results is well known. In addition, while practitioners place a high value on research, they do not read many research papers. This paper attempts to define and prioritise future research in robotics using the analytical hierarchy process (AHP). Fifteen research alternatives and gaps, five performance criteria, eight industry types, and six production processes, investigated by both academics and practitioners, are filtered to six alternatives, four performance criteria, three industry types, and three production processes, respectively, based on the most important factors in decision-making. Subsequently, they are analysed by the Expert Choice software. This research aims at bridging the gap between academics and practitioners in robotics research and at conducting research that is relevant to industry. The results indicate that the research in multi-robot control ranked first with 26.8%, followed by the research in safe control with 23.3% and the research in remote robot supervision with 19.0%. The research in force control ranked fourth with 17.8%, followed by the research in 3D vision and wireless communication with 8.4% and 6.4%, respectively. Based on the results, the academics involved in robotics research should direct their effort to the research activities that received the highest priority in the AHP model

Modeling approach to evaluating reduction in stress intensity factor in center-cracked plate with piezoelectric actuator patches

Active repairs using piezoelectric actuators can play a significant role in reducing the crack damage propagation in thin plate structures. Mode-I crack opening displacement is the most predominant one in tension, and it is responsible for the failure which in turn affects the load carrying capability of the cracked structure. In addition, there are limited studies that investigated the effect of the piezoelectric actuator over mode-I active repair. In this study, the mode-I stress intensity factor for a plate with a center crack, and a bonded piezoelectric actuator was modeled using the linear elastic fracture mechanics. For this, an analytical closed-form solution is developed using the virtual crack closure technique taking into account mode-I as the only effective mode, coupling effects of the piezoelectric patch, and the singular stress at the crack tip. In addition, the total stress intensity factor was obtained by the superposition of the stress intensity factor obtained from the stresses produced by the piezoelectric actuators on the crack surfaces as the only external loads on the cracked plate and the stress intensity factor due to the far-field tension load. The proposed analytical model for mode-I stress intensity factor was verified by a finite element–based approach using ANSYS finite element software. The results demonstrated a good agreement between the analytical and finite element models with a relative error of less than 4% in all the cases studied. The results illustrated that the piezoelectric patch is efficient in reducing stress intensity factor when an extension mode of the actuator is applied. However, applying a contraction mode of the piezoelectric actuators produced negative strain which increased the stress intensity factor and thus the severity of the cracked structure and could lead to damage propagation

Modeling different repair configurations of an aluminum plate with a hole

This paper investigates the influence of repair configuration on a rectangular plate with a circular hole and subjected to uniform tensile load. The fundamental idea is to study the stress created by either a composite or piezoelectric (PZT) patch on a hole along the width of a rectangular plate. Finite element ANSYS software was used to evaluate the stress concentration factor (SCF) around the hole when the plate is unrepaired, repaired with a piezoelectric patch, and repaired with single and double composite patches. The results showed that the different repair configurations were effective in improving the state of the stress concentration with the positive electric field in the PZT being the most effective in decreasing stress concentration along the width of the rectangular plate. The results also showed that the SCF reduction increased with the decrease of the hole diameter to the plate width ratio (D/W) for the composite patch repair. © BEIESP

Implementing ISO 14001 and Environmental Performance Evaluation: A Logistic Regression Model

Due to the growing popularity of environmental management systems and the ongoing debate among practitioners and researchers concerning the influence of environmental management systems on environmental performance, there is a need to assess how the implemented environmental management systems impact the environment. The current study examines the relationship between the guidelines provided by the ISO 14031 and ISO 14001 standards from three aspects, namely, utilizing information and data, planning for environmental performance and reviewing and improving environmental performance. This study will utilize a binary logistic regression to model and analyse the link between ISO 14001 and ISO 14031 using a 7-point Likert scale questionnaire. A total of 590 companies operating within the Saudi Arabia industrial sector were invited to take part in the study. The collection of data using questionnaires lasted from January to March 2019, and the results were analysed and compared with those of related studies. The model included a dependent variable representing whether the company is certified or not for ISO 14001 and 13 independent variables representing the main ISO 14031 guidelines. The research findings revealed that the developed model predicts 92.8% of the values, and the remaining 7.2% of the values are not covered. Thirteen independent variables were positively correlated with the dependent variable, indicating that the company is certified. The results of this study contribute significantly to the determination of the relationship between environmental performance and ISO 14001 certification

Experimental study on energy absorption of foam filled kraft paper honeycomb subjected to quasi-static uniform compression loading

A statistical analysis was performed first to evaluate the effect of factor and to obtain the optimum configuration of Kraft paper honeycomb. The factors considered in this study include density of paper, thickness of paper and cell size of honeycomb. Based on the three level factorial design,two-factor interaction model (2FI) was developed to correlate the factors with specific energy absorption and specific compression strength. From the analysis of variance (ANOVA), the most influential factor on responses and the optimum configuration was identified. Then, Kraft paper honeycomb with optimize configuration is used to fabricate foam-filled paper honeycomb with five different densities of polyurethane foam as filler (31.8, 32.7, 44.5, 45.7, 52 kg/m3). The foam-filled paper honeycomb are subjected to quasi-static compression loading. Failure mechanism of the foam filled honeycomb were identified, analyzed and compared with the unfilled paper honeycomb. The peak force and energy absorption capability of foam filled paper honeycomb are increases up to 32% and 30% compared to the summation of individual components

Shape control of composite plates with piezoelectric actuators

In this paper, shape control of composite plates using piezoelectric actuators is being investigated. The goal of this study was to see how composite plates behave when they are integrated with piezoelectric actuators. Modelling and simulation were done using COMSOL Multiphysics software and results were validated using previously published studies. Parametric investigations were carried out to inves-tigate the effect of patch locations and stacking sequences with respect to suppression of deflection. The obtained results showed that for uniformly distributed load considered in this work the patches worked effectively when they were placed at the center of the composite plate

Derivation of stress intensity factor for a cracked plate with an integrated piezoelectric actuator

The purpose of this work is to derive an analytical model under linear-elastic fracture mechanics (LEFM) to represent the effect of piezoelectric actuation on energy release rate and Mode I stress intensity factor for a plate subjected to a uniform biaxial tension stress . The piezoelectric actuator is inducing a local force above the crack area via an external voltage to reduce the stress singularity around the crack tip. The results indicate that the stress intensity factor decreases with the application of the piezoelectric actuator voltage

Finite element simulation of electro-mechanical impedance technique

Electro-mechanical impedance method is emerging as an important and powerful technique for structural health monitoring (SHM). Active elements of the technique are Piezoelectric Wafer Active Sensor (PWAS) bonded on the structure. Modeling and simulation of PWAS and host structure play an important role in the SHM applications with PWAS. For decades finite element method has been extensively applied in the analysis of piezoelectric materials and structures. In this paper, piezoelectric element and a host metallic structure were modeled using Ansys finite element software to find the Electromechanical Impedance (EMI) according to the signal frequency. After that, the EMI signature of the beam was found for different position of the PWAS patch. The study shows that sensor position may directly control the EMI signature