326 research outputs found

    Image Encryption Based on Diffusion and Multiple Chaotic Maps

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    In the recent world, security is a prime important issue, and encryption is one of the best alternative way to ensure security. More over, there are many image encryption schemes have been proposed, each one of them has its own strength and weakness. This paper presents a new algorithm for the image encryption/decryption scheme. This paper is devoted to provide a secured image encryption technique using multiple chaotic based circular mapping. In this paper, first, a pair of sub keys is given by using chaotic logistic maps. Second, the image is encrypted using logistic map sub key and in its transformation leads to diffusion process. Third, sub keys are generated by four different chaotic maps. Based on the initial conditions, each map may produce various random numbers from various orbits of the maps. Among those random numbers, a particular number and from a particular orbit are selected as a key for the encryption algorithm. Based on the key, a binary sequence is generated to control the encryption algorithm. The input image of 2-D is transformed into a 1- D array by using two different scanning pattern (raster and Zigzag) and then divided into various sub blocks. Then the position permutation and value permutation is applied to each binary matrix based on multiple chaos maps. Finally the receiver uses the same sub keys to decrypt the encrypted images. The salient features of the proposed image encryption method are loss-less, good peak signal-to-noise ratio (PSNR), Symmetric key encryption, less cross correlation, very large number of secret keys, and key-dependent pixel value replacement.Comment: 14 pages,9 figures and 5 tables; http://airccse.org/journal/jnsa11_current.html, 201

    Implementation of Improved Method on Embedded Surveillance System with Reduced Power Usage

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    In this project design and implement a home embedded surveillance system with ultra-low alert power. Traditional surveillance systems suffer from an unnecessary waste of power and the shortcomings of memory conditions in the absence of invasion. In this design we pressure sensors as the alert group in windows and doors where an intruder must pass through. These low-power alert sensors wake up the MCU (Micro Controller Unit) which has power management for the ultrasonic sensors and PIR sensors indoors. This state transition method saves a large number of sensors required for the alert power. We also use the Majority Voting Mechanism (MVM) to manage the sensor groups to enhance the probability of multiple sensors sensing. After the MCU sends the sensor signals to the embedded system, the program starts the Web camera. Our sensing experiment shows that we reduce the system’s power consumption Keywords: Embedded Surveillance System, PIR Sensor, Ultrasonic Sensor, Low-PowerStat

    Potential of Vibration Studies in the Soil Characterization Around Power Plants – A Case Study

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    Propagation characteristics of waves generated by the various sources of vibration can be dependent on the type of the generated waves, which can be accessed by measuring particle motion in vertical, longitudinal and transverse direction. The monitoring of motion in three directions on the ground surface and in depth is important for the characterization of propagating waves. Vibrations of the machine foundations induce elastic waves in soil, which may affect surrounding buildings. Generally, the attenuation of vibrations on surface is composed of two factors namely geometric damping and material damping. The paper is an experimental investigation with regard to the ground vibrations and its attenuation during the operation of power plants. The study helps in characterizing the soil around a power plant. The investigation was carried out on two power plants, which runs at the same frequency, and soil characterization was done based on the study. Measurements were taken on the level ground for the harmonic waves generated from the diesel power plant. Study is found to be helpful in characterizing the soil based on the frequency independent material damping coefficients, low amplitude shear modulus etc. on the plant premises. The effect of these vibrations on adjoining areas can be well predicted based on the soil medium

    Computational Analysis of Heat Transfer through Fins with Different Types of Notches

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    The Engine is one of the important component in an automobile which is subjected to high temperature and thermal stresses. In order to cool the engine the fins are another component which are used to dissipate the heat from the Engine. Fins are generally used to increase the heat transfer rate from the system to the surroundings. By doing computational flow analysis on the engine cooling fins, it is helpful to know about the heat dissipation rate and the Principle implemented in this project is to increase the heat transfer rate, so in this analysis, the fins are modified by putting different types of notches and are of same material. The knowledge of efficiency and effectiveness of the fins are necessary for proper designing of fins. The main objective of our analysis is to determine the flow of heat at various notches available and the analysis is done by using ANSYS – CFD Fluent software

    Ply-stacking effects on mechanical properties of Kevlar-29/banana woven mats reinforced epoxy hybrid composites

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    © The Author(s) 2022. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, https://creativecommons.org/licenses/by-nc/4.0/Development of new hybrid laminated composites of Kevlar-29 (K-29)/banana fiber (Musa acuminata) mats to meet future demand for fiber reinforced polymer (FRP) composites has been investigated. The different ply-stacking sequenced Kevlar (K)/natural (N) banana reinforced epoxy polymeric hybrid composite samples were designated as KN1, KN2, KN3, KN4, KN5 and KN6, in addition to NN7 and KK8 for single or non-hybrid FRP (control) composite samples. The ply-stacking effects on mechanical properties of all the laminated composite were investigated. The maximum tensile, flexural, impact and interlaminar shear strengths (ILSS) were obtained with sample KN4, because of the stacking of its Kevlar and natural banana mats, which was K2/N4/K2 of 8 layers and different from other stacking sequences. The percentage improvements on tensile strength of sample KN4 when compared with other hybrid composite samples KN1, KN2, KN3, KN5 and KN6 were 6.3, 4.4, 3.6, 13.1 and 11.3%, respectively. While, same optimum sample KN4 recorded highest flexural strength among hybrid samples with percentage improvements of 122.19, 70.97, 31.03 and 83.68% when compared with other hybrid samples KN2, KN3, KN5 and KN6, respectively. Similar trend of results was obtained for their tensile and flexural moduli. But, both hybrid composite samples KN3 and KN4 recorded higher impact strengths of 3.0 and 2.8 J, respectively, when compared with other hybrid counterparts. The tensile and flexural strengths of sample KN4 were 147.48 and 223.69 MPa, respectively. The tensile properties of various theoretical model were compared with experimental values.Peer reviewe

    Effect of Carbon Black from Ageratina Adenophora and Various other Carbon Anode Plate Additives on the Performance of Lead Acid Batteries

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    Received: 16.02.2024. Revised: 14.03.2024. Accepted: 21.03.2024. Available online: 08.04.2024.The small-sized PbO2 particles form a well-interconnected agglomerate structure, aligning with micro and macro structure of NAM.The cells made up of CBAa and Carbon Vulcan the capacity loss was less even after 175 cycles.Capacity loss to a larger extent in case of Carbon N550, Carbon N330 and Carbon Vulcan.The incorporation of carbon materials in batteries serves to enhance its performance by improving conductivity, achieving uniform active material distribution, increasing capacity, mitigating sulfation, extending cycle life, and considering potential environmental benefits. Even though several possible mechanisms were reported, how exactly carbon works is not fully understood. In the present study a new form of carbon black was prepared from Ageratina adenophora (CBAa) and investigated for its impact on the electrical conductivity of the negative active material in 2 V lead acid cell. The performance was compared with other commercially available carbons like Graphite PG-10, Carbon N550, Carbon N330 and Carbon Vulcan. The carbon was characterised by XRD, SEM and grain size analysis. The initial capacity of the cell was consistently higher and remained stable at 4.6 W∙h; in the life cycle analysis, the cells showed 290 cycles. The post-life cycle test analysis showed that only a white layer on multiple plates indicating the onset of sulfation and there is no corrosion. The performance of the CBAa prepared in the present work was found to be better when compared with the commercially available carbons.The authors thank the Centre of Material Chemistry and Centre of Food and Nanotechnology, Karpagam Academy of Higher Education for using their instrument facility

    Variability in soil properties influencing pigeonpea (Cajanus cajana L.) yield: a multivariate statistical analysis [version 3; peer review: 2 approved]

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    Aims: The aim of the study was to reveal the variability in soil properties influencing pigeonpea (Cajanus cajana L.) seed yield under semi-arid rainfed condition. Methods: Soils were initially classified into series level and further these series were divided into soil-phase units. For two site years viz., 2018-19 and 2019-20, surface soil samples from each soil-phase unit were collected before sowing of pigeonpea and subsequently crop growth parameters at critical stages were recorded. Results: The principal component analysis with varimax rotation resulted in seven components for both the site years, having eigenvalues greater than one, explained more than 80% of the variability. The step wise linear regression analysis showed that the pigeonpea seed yield was linearly correlated with PC3 (p<0.01), PC4 (p<0.01) and PC7 (p<0.05) of soil properties with R2 = 0.679, during 2018-19. Whereas, during 2019-20, the seed yield was linearly correlated with PC1 (p<0.01), PC3 (p<0.01) and PC6 (p<0.05) with R2 = 0.677. In site year 1, the available P2O5, Fe, Zn, S, Cu, number of pods, surface soil moisture determined the yield. In site year 2, the available K2O, P2O5, Fe, Zn, S, clay, CEC and available water content determined the yield. All these variables together explain variability in yield

    Selective inhibition of plasma membrane calcium ATPase 4 improves angiogenesis and vascular reperfusion

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    Aims Ischaemic cardiovascular disease is a major cause of morbidity and mortality worldwide. Despite promising results from pre-clinical animal models, VEGF-based strategies for therapeutic angiogenesis have yet to achieve successful reperfusion of ischaemic tissues in patients. Failure to restore efficient VEGF activity in the ischaemic organ remains a major problem in current pro-angiogenic therapeutic approaches. Plasma membrane calcium ATPase 4 (PMCA4) negatively regulates VEGF-activated angiogenesis via inhibition of the calcineurin/NFAT signalling pathway. PMCA4 activity is inhibited by the small molecule aurintricarboxylic acid (ATA). We hypothesize that inhibition of PMCA4 with ATA might enhance VEGF-induced angiogenesis. Methods and results We show that inhibition of PMCA4 with ATA in endothelial cells triggers a marked increase in VEGF-activated calcineurin/NFAT signalling that translates into a strong increase in endothelial cell motility and blood vessel formation. ATA enhances VEGF-induced calcineurin signalling by disrupting the interaction between PMCA4 and calcineurin at the endothelial-cell membrane. ATA concentrations at the nanomolar range, that efficiently inhibit PMCA4, had no deleterious effect on endothelial-cell viability or zebrafish embryonic development. However, high ATA concentrations at the micromolar level impaired endothelial cell viability and tubular morphogenesis, and were associated with toxicity in zebrafish embryos. In mice undergoing experimentally-induced hindlimb ischaemia, ATA treatment significantly increased the reperfusion of post-ischaemic limbs. Conclusions Our study provides evidence for the therapeutic potential of targeting PMCA4 to improve VEGF-based pro-angiogenic interventions. This goal will require the development of refined, highly selective versions of ATA, or the identification of novel PMCA4 inhibitors
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