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This article presents a new class of generalized transmuted lifetime distributions which includes a large number of lifetime distributions as sub-family. Several important mathematical quantities such as density function, distribution function, quantile function, moments, moment generating function, stress-strength reliability function, order statistics, R\'enyi and q-entropy, residual and reversed residual life function, and cumulative information generating function are obtained. The methods of maximum likelihood, ordinary least square, weighted least square, Cram\'er-von Mises, Anderson Darling, and Right-tail Anderson Darling are considered to estimate the model parameters in a general way. Further, a well-organized Monte Carlo simulation experiments have been performed to observe the behavior of the estimators. Finally, two real data have also been analyzed to demonstrate the effectiveness of the proposed distribution in real-life modeling., Comment: 26 pages, 8 figures

Dombi et al. (2019) introduced a three parameter omega distribution and showed that its asymptotic distribution is the Weibull model. We propose a new record-based transmuted generalization of the unit omega distribution by considering Balakrishnan and He (2021) approach. We call it the RTUOMG distribution. We derive expressions for some statistical quantities, like, probability density function, distribution, hazard function, quantile function, moments, incomplete moments, inverted moments, moment generating function, Lorenz curve, and Bonferroni curve of the proposed distribution. The numerical values of various measures of central tendency and coefficient of skewness and kurtosis are also presented. Concepts of stochastic ordering and some results related to ordered statistics of the RTUOMG distribution are discussed. The parameters of the RTUOMG distribution are estimated using five distinct estimators. Additionally, the Monte Carlo simulations are performed to assess the performance of these estimators. Finally, two real data sets are analyzed to demonstrate the utility of the RTUOMG distribution., Comment: 26 pages, 14 figures

Vigorous efforts to harness the topological properties of light have enabled a multitude of novel applications. Translating the applications of structured light to higher spatial and temporal resolutions mandates their controlled generation, manipulation, and thorough characterization in the short-wavelength regime. Here, we resort to high-order harmonic generation (HHG) in a noble gas to upconvert near-infrared (IR) vector, vortex, and vector-vortex driving beams that are tailored respectively in their Spin Angular Momentum (SAM), Orbital Angular Momentum (OAM), and simultaneously in their SAM and OAM. We show that HHG enables the controlled generation of extreme-ultraviolet (EUV) vector beams exhibiting various spatially-dependent polarization distributions, or EUV vortex beams with a highly twisted phase. Moreover, we demonstrate the generation of EUV vector-vortex beams (VVB) bearing combined characteristics of vector and vortex beams. We rely on EUV wavefront sensing to unambiguously affirm the topological charge scaling of the HHG beams with the harmonic order. Interestingly, our work shows that HHG allows for a synchronous controlled manipulation of SAM and OAM. These EUV structured beams bring in the promising scenario of their applications at nanometric spatial and sub-femtosecond temporal resolutions using a table-top harmonic source., Comment: 13 pages, 6 figures

In many places all over the world rural and remote areas lack proper connectivity that has led to increasing digital divide. These areas might have low population density, low incomes, etc., making them less attractive places to invest and operate connectivity networks. 6G could be the first mobile radio generation truly aiming to close the digital divide. However, in order to do so, special requirements and challenges have to be considered since the beginning of the design process. The aim of this white paper is to discuss requirements and challenges and point out related, identified research topics that have to be solved in 6G. This white paper first provides a generic discussion, shows some facts and discusses targets set in international bodies related to rural and remote connectivity and digital divide. Then the paper digs into technical details, i.e., into a solutions space. Each technical section ends with a discussion and then highlights identified 6G challenges and research ideas as a list., Comment: A 6G white paper, 17 pages

High-power multicycle THz radiation is highly sought after with applications in medicine, imaging, spectroscopy, characterization and manipulation of condensed matter, and could support the development of next-generation compact laser-based accelerators with applications in electron microscopy, ultrafast X-ray sources and sub-femtosecond longitudinal diagnostics. Multicycle THz-radiation can be generated by shooting an appropriate laser through a periodically poled nonlinear crystal, e.g. lithium niobate (PPLN). Unfortunately, the manufacturing processes of PPLNs require substantially strong electric fields $\mathcal{O}(10~kV/mm)$ across the crystal width to locally reverse the polarization domains; this limits the crystal apertures to below 1 cm. Damage threshold limitations of lithium niobate thereby limits the laser power which can be shone onto the crystal, which inherently limits the production of high-power THz pulses. Here we show that in the THz regime, a PPLN crystal can be mechanically constructed in-air by stacking lithium niobate wafers together with 180$^{\circ}$ rotations to each other. The relatively long (mm) wavelengths of the generated THz radiation compared to the small gaps ($\sim$10 $\mu$m) between wafers supports a near-ideal THz transmission between wafers. We demonstrate the concept using a Joule-class laser system with $\sim$50 mm diameter wafers and measure up to 1.3 mJ of THz radiation corresponding to a peak power of $\sim$35 MW, a 50 times increase in THz power compared to previous demonstrations. Our results indicate that high-power THz radiation can be produced with existing and future high-power lasers in a scalable way, setting a course toward multi-gigawatt THz pulses. Moreover the simplicity of the scheme provides a simple way to synthesize waveforms for a variety of applications.

Industrial radiography has its inimitable role in non-destructive examinations. Industrial radiography devices, consisting of significantly high activity of the radioisotopes, are operated manually by remotely held control unit. Malfunctioning of these devices may cause potential exposure to the operator and nearby public, and thus should be practiced under a systematic risk control. To ensure the radiation safety, proactive risk assessment should be implemented. Risk assessment in industrial radiography using the Failure Modes & Effect Analysis (FMEA) for the design and operation of industrial radiography exposure devices has been carried out in this study. Total 56 component failure modes were identified and Risk Priority Numbers (RPNs) were assigned by the FMEA expert team, based on the field experience and reported failure data of various components. Results shows all the identified failure modes have RPN in the range of 04 to 216 and most of the higher RPN are due to low detectability and high severity levels. Assessment reveals that increasing failure detectability is a practical and feasible approach to reduce the risk in most of the failure modes of industrial radiography devices. Actions for reducing RPN for each failure mode have been suggested. Feasibility of FMEA for risk assessment in industrial radiography has been established by this study