Hybrid data encryption model integrating multi-objective adaptive genetic algorithm for secure medical data communication over cloud-based healthcare systems

Multimedia Tools and Applications - The exponential rise in the development of cloud computing environments in the healthcare field, the protection and confidentiality of the medical records become...     

Lightweight Feistel structure based hybrid-crypto model for multimedia data security over uncertain cloud environment

The exponential rise in software computing and internet technologies have broadened the horizon of cloud computing applications serving numerous purposes like business processes, healthcare, finance, socialization, etc. In the last few years the increase is security breaches and unauthorized data access has forced industry to achieve computationally efficient and robust security system. The increase in multimedia data communication over different cloud applications too demands an efficient security model, which is expected to have low computational complexity, negligible quality-compromise and higher security robustness. Major conventional security-systems like cryptography and steganography undergo high computational overhead, thus limiting their potential towards cloud-communication where each data input used to be of large size and a gigantic amount of multimedia data is shared across the network. To alleviate above stated problems and enable a potential solution, in this paper a highly robust Lightweight Feistel Structure based Substitution Permutation Crypto Model is developed for multimedia data security over uncertain cloud environment. Our proposed model applies substitution permutation crypto concept with Feistel structure which performs substitution-permutation over five rounds to achieve higher confusion and diffusion. To retain higher security with low computation, we applied merely 64-bit block cipher and equal key-size. MATLAB based simulation revealed that the proposed lightweight security model achieves better attack-resilience even maintaining low entropy, high-correlation, and satisfactory computation time for multimedia data encryption. Such robustness enables our proposed security model to be applied for real-world cloud data security.

     

Comparison of measured and satellite-derived spectral diffuse attenuation coefficients for the Arabian Sea

We present here the results of our study comparing the spectral diffuse attenuation coefficients K _d(λ) measured in the Arabian Sea with those derived from the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) using three algorithms, of which two are empirical-data-driven and one is semi-analytical. The measurements were carried out in all water types and the mean values of the measured spectral K _d(λ) are 0.105, 0.092, 0.077, 0.082, 0.110 and 0.490 m^?1 for wavelength λ at 412, 443, 490, 510, 555 and 670 nm, respectively. This profile corresponds to a chlorophyll value of about 1 mg m^?3. The maximum values of the measured K _d correspond to waters with chlorophyll of about 8 mg m^?3. Though the satellite-derived K _d(λ) are found to be overestimated in all bands, we have observed good correlations between the measured and satellite-derived values in all bands, and excluding the band at 670 nm, the mean absolute percent deviations are observed to be less than 50% in all bands. The performance of the data-driven empirical methods was found to be consistent in all the bands, except at the red band of 670 nm, which is uncorrelated with the measured values and has large errors. The performances of the empirical methods depend on the accuracy of the band ratios of the retrieved remote sensing reflectance. Though the performance of the semi-analytical algorithm is found to be spectrally varying, with large positive bias observed in the blue regions, this algorithm is recommended for hyperspectral applications. The performance of the semi-analytical algorithm could be improved by having a robust algorithm to accurately derive spectral inherent optical properties of absorption and backscattering coefficients from the satellite data.     

A synthesis study of phosphonated PSEBS for high temperature proton exchange membrane fuel cells

A series of novel phosphonated proton exchange membranes has been prepared using poly(styrene‐ethylene/butylene‐styrene) block copolymer (PSEBS) as base material. Phosphonic acid functionalization of the polymer was performed by a simple two‐step process, via chloromethylation of PSEBS followed by phosphonation utilizing the Michaels–Arbuzov reaction. The successful phosphonation of the polymers were characterized by NMR and Fourier transform infrared. The phosphonated ester form of the membranes were obtained by solvent evaporation method and hydrolyzed to get a proton conducting membrane. The membrane properties such as ion exchange capacity, water uptake and proton conductivity at various temperatures were examined for their suitability to be utilized as a high temperature polymer electrolyte. Additionally, the morphology, thermal, and mechanical properties of the synthesized membranes were investigated, using scanning electron microscope, thermogravimetric analysis, and tensile test, respectively. The effective (anhydrous) proton conductivity was studied with respect to various degrees of functionalization. From the studies, the membranes were found to have a comparatively good conductivity and one of the membranes reached the maximum value of 5.81 mS/cm² at 140 °C as measured by impedance analyzer. It was found that the synthesized membranes were mechanically durable, chemically, and thermally stable. Hence, the synthesized phosphonated membranes could be a promising candidate for high temperature polymer electrolyte fuel cell applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45954.     

Fostering positive attitude in probability learning using graphing calculator

Although a plethora of research evidence highlights positive and significant outcomes of the incorporation of the Graphing Calculator (GC) in mathematics education, its use in the teaching and learning process appears to be limited. The obvious need to revisit the teaching and learning of Probability has resulted in this study, i.e. to incorporate GC in the teaching and learning of Probability, specifically on the issue of attitudes towards learning probability. The objective is to examine the effectiveness of GC interactive learning, particularly on students’ attitudes towards Probability. A total of 65 foundation students participated in this study; 32 students in the experimental group and 33 in the control group. The teaching approaches varied between the groups. While the experimental group experienced the GC approach, the control group encountered the conventional teaching approach of chalk and talk. Students’ attitude towards learning probability was assessed using the Probability Attitude Inventory (PAI), was administered prior to and after the study. The results show significantly difference in the improved attitude towards Probability between the groups, particularly in terms of usefulness of Probability, interest in Probability and self-concept in Probability. This study provides evidence that learning Probability with GCs benefits students.