A secure reversible color image watermarking scheme based on LBP,lagrange interpolation polynomial and weighted matrix

Multimedia Tools and Applications - Secure reversible watermarking schemes are essential for image authentication and tamper detection in medical, military and government applications. In this...     

Tree parity machine guided patients’ privileged based secure sharing of electronic medical record: cybersecurity for telehealth during COVID-19

In the COVID-19 pandemic, telehealth plays a significant role in the e-healthcare. E-health security risks have also risen significantly with the rise in the use of telehealth. This paper addresses one of e-health’s key concerns, namely security. Secret sharing is a cryptographic method to ensure reliable and secure access to information. To eliminate the constraint that in the existing secret sharing schemes, this paper presents Tree Parity Machine (TPM) guided patients’ privileged based secure sharing. This is a new secret sharing technique that generates the shares using a simple mask based operation. This work considers addressing the challenges presents in the original secret sharing scheme. This proposed technique enhances the security of the existing scheme. This research introduces a concept of privileged share in which among k number of shares one share should come from a specific recipient (patient) to whom a special privilege is given to recreate the original information. In the absence of this privileged share, the original information cannot be reconstructed. This technique also offers TPM based exchange of secret shares to prevent Man-In-The-Middle-Attack (MITM). Here, two neural networks receive common inputs and exchange their outputs. In some steps, it leads to full synchronization by setting the discrete weights according to the specific rule of learning. This synchronized weight is used as a common secret session key for transmitting the secret shares. The proposed method has been found to produce attractive results that show that the scheme achieves a great degree of protection, reliability, and efficiency and also comparable to the existing secret sharing scheme.

     

Trinary registers and counters using savart plate and spatial light modulator for optical computation in multivalued logic

Registers and counters are the most important devices in any system of computations. In this paper we have communicated the trinary registers and counters in modified trinary number （MTN） system. It is suitable for the optical computing and other applications in multivalued logic system. Here the savart plate and spatial light modulator （SLM） based optoelectronic circuits have been used to exploit the optical tree architecture （OTA） in optical interconnection network.     

纺织品的容许色差

色彩推动了纺织品市场的发展。对于生产者和厂家来说色差问题一直是一个颇具争议的现象，色差数据并不是总能够符合人们对颜色深浅的视觉估计。这里给出了一些不同颜色深浅的容许量数据(△E)，叙述了如何正确地选择计算色彩差异的公式以及这些公式的局限性，同时也讨论了关于颜色的视觉估计以及电脑测色系统之间的关系，介绍了用分光光度分析不同表面特征的织物的方法．     

Enhancement of CO laser efficiency by addition of xenon

The influence of xenon on the performance of a CO laser has been studied. The addition of xenon produced an increase in the conversion efficiency up to 40 percent and a change in the spectral intensity distribution of the laser output.     

Spectral coincidences between emission lines of the CO laser and absorption lines of nitrogen oxides

Several spectral coincidences between carbon-monoxide laser emission lines and absorption lines of NO and N2O4have been observed, and absorption measurements have been taken. These data are presented and discussed along with similar spectral coincidence observations made previously using the helium-neon and iodine lasers. Other coincidences between CO-laser lines and NO2absorption lines are predicted from a study of recently available high-resolution-spectroscopy literature. Due to the narrow line widths of gas-laser lines, the coincidences reported here can be applied to the selective sensing of these constituents in the atmosphere.     

Lattice Boltzmann simulation of lid-driven swirling flow in confined cylindrical cavity

Lid-driven swirling flow in a confined cylindrical cavity is investigated using lattice Boltzmann equation (LBE) method. The steady, 3-dimensional flow is examined at different aspect (height-to-radius) ratios and Reynolds numbers. The LBE simulations are carried out using the multiple-relaxation-time method. The LBE simulation results are compared with the results of a finite volume solution of Navier-Stokes equations and with published experimental data. Numerical results are presented for cylindrical cavities with two aspect ratios of 1.5 and 2.5, and three Reynolds numbers of 990, 1010 and 1290. Effects of the aspect ratio and Reynolds number on the size, position and breakdown of the central recirculation bubble, together with the flow pattern in the cavity, are determined. Detailed topological features of the flow, such as, (1) structure and breakdown of the vortex along the axis, (2) azimuthal component of vorticity, and (3) circulation strength of flow about the axis are investigated and compared with previous findings from experiments and theory.The predicted results from LBE simulations are consistent with experiments and theory. Steady results reveal the occurrence of a breakdown bubble in agreement with the regime diagram due to Escudier. The vortex breakdown around a region may be characterized by a change in sign of the azimuthal vorticity near such locations. Investigations are carried out on the characteristics of angular momentum when the vortex breakdown occurs. The theoretical criterion for vortex breakdown to occur, as proposed by Brown and Lopez is verified using the numerical data obtained from the simulations.     

A View on the General Practice in Engineering Failure Analysis

Analysis of engineering failures is a complex process that requires information from personnel having expertise in many areas. From the information gathered, a failure analyst tries to discover what was fundamentally responsible for the failure. This fundamental cause is termed the “root cause” and helps in the determination of the sequence of events that led to the final failure. Root cause analysis also helps in finding solutions to the immediate problem and provides valuable guidelines as to what needs to be done to prevent recurrence of similar failures in future. However, experience suggests that most failure analyses fall short of this goal. A significant number of failure analysts incorrectly use the term “root cause” when what they really establish is the primary cause of failure or simple physical cause. This paper examines a few service failures to demonstrate that the term root cause is not adequately understood.     

Mineralogical and structural characterization of the sediments of Krishna Godavari and Mahanadi Basin and their influences on hydrate formation kinetics

Structural and mineralogical characterization of sediment samples of Krishna Godavari (KG) and Mahanadi (MH) basin was performed with the aim of providing in-depth analysis of the effect of mineralogy, grain size and other properties on the hydrate formation. Bulk mineralogy and clay mineralogy of the sediments analyzed through different characterization techniques like X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) that was associated with Energy Dispersive X-Ray (EDX) analysis. Quartz was the main component observed in the sediment samples. A relation between particle size and pore size was also established through particle size (DLS) and pore size characterization (BET) techniques. Finer clay materials were leading in both KG and MH basin samples having slight variation in their quartz content. Illite and smectite were the dominating clay minerals found in the sediments with calcite and albite being the other contributing minerals. Framboids as the pyrites were also observed in sediments and were clearly visible in FESEM observations. Hydrate formation studies were also performed in the sediments to observe the effect of their sedimentology and geology on the occurrence of hydrates in oceanic sediments. Hydrate formation in sediments occurred in less time as compared to pure water system with an accelerated rate of nucleation as per the observations. Kinetic studies were also performed that showed the higher initial rate of hydrate formation in sediments that could be due to the high surface area and additional nucleation sites provided by the sediments as confirmed by BET analysis. Rate constants and other kinetic parameters were also calculated by assuming the first order reaction kinetics of hydrate formation.     

Perceptual hashing scheme using KAZE feature descriptors for combinatorial manipulations

Multimedia Tools and Applications - Perceptual image hashing methods utilize the visual phenomenon of the images and produce a fixed-length hash function and this hash value can be utilized for...