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Chaotic Waveform-Based Signal Design for Noncoherent SWIPT Receivers
No full textThis paper proposes a chaotic waveform-based multi-antenna receiver design for simultaneous wireless information and power transfer (SWIPT). Particularly, we present a differential chaos shift keying (DCSK)-based SWIPT multiantenna receiver architecture, where each antenna switches between information transfer (IT) and energy harvesting (EH) modes depending on the receiver\u27s requirements. We take into account a generalized frequency-selective Nakagami-m fading model as well as the nonlinearities of the EH process to derive closed-form analytical expressions for the associated bit error rate (BER) and the harvested direct current (DC), respectively. We show that, both depend on the parameters of the transmitted waveform and the number of receiver antennas being utilized in the IT and EH mode. We investigate a trade-off in terms of the BER and energy transfer by introducing a novel achievable \u27success rate - harvested energy\u27 region. Moreover, we demonstrate that energy and information transfer are two conflicting tasks and hence, a single waveform cannot be simultaneously optimal for both IT and EH. Accordingly, we propose appropriate transmit waveform designs based on the application specific requirements of acceptable BER or harvested DC or both. Numerical results demonstrate the importance of chaotic waveform-based signal design and its impact on the proposed receiver architecture
Conditional Variable Screening for Ultra-High Dimensional Longitudinal Data With Time Interactions
No full textIn recent years, we have been able to gather large amounts of genomic data at a fast rate, creating situations where the number of variables greatly exceeds the number of observations. In these situations, most models that can handle a moderately high dimension will now become computationally infeasible or unstable. Hence, there is a need for a prescreening of variables to reduce the dimension efficiently and accurately to a more moderate scale. There has been much work to develop such screening procedures for independent outcomes. However, much less work has been done for high-dimensional longitudinal data in which the observations can no longer be assumed to be independent. In addition, it is of interest to capture possible interactions between the genomic variable and time in many of these longitudinal studies. In this work, we propose a novel conditional screening procedure that ranks variables according to the likelihood value at the maximum likelihood estimates in a marginal linear mixed model, where the genomic variable and its interaction with time are included in the model. This is to our knowledge the first conditional screening approach for clustered data. We prove that this approach enjoys the sure screening property, and assess the finite sample performance of the method through simulations
Differential fault attack on SPN-based sponge and SIV-like AE schemes
No full textThis paper presents the first instance of a successful differential fault attack (DFA) on the nonce-based authentication scheme PHOTON-BEETLE, which was a finalist but not the winner of the NISTLwC competition. Furthermore, the paper also reveals the first differential fault attacks on several other NISTLwC schemes, including ORANGE, SIV-TEM-PHOTON, and ESTATE, which are based on sponge and SIV techniques. In general, it is a challenging task to perform DFA for any nonce-based sponge/SIV-based AE because of a unique nonce in the encryption query. However, the decryption procedure (with a fixed nonce) is still susceptible to DFA. We propose different fault attack models, and also give theoretical estimates of the number of faulty queries to get multiple forgeries. Our simulated values corroborate closely the theoretical estimates. Finally, we devise an algorithm to recover the state based on the collected forgeries. Under the random fault attack model, to retrieve the secret key, we need approximately 237.15 number of faulty queries. Also, the offline time and memory complexities of this attack are respectively 216 and 210 nibbles. Whereas, under the random bit fault attack model, around 211.5 number of faulty queries are required to retrieve the key for PHOTON-based schemes and 213.1 for AES-based scheme ESTATE. In the known fault attack model, we need around 211.05 number of faulty queries to retrieve the secret key for PHOTON-based schemes and 213.01 for AES-based scheme ESTATE. The time and memory complexities of the state recovery attack (for PHOTON-based schemes) are respectively 211 and 29 nibbles. Further, we have reduced the number of faulty queries to 29.32 under the precise bit-flip fault model
Discrepancy estimates for some linear generalized monomials at prime arguments
No full textWe obtain an upper bound for the discrepancy of the sequence ([pα] β) generated by the generalized monomial [xα] β , where p runs through the set of all primes and α , β are irrational numbers satisfying certain conditions
Distance synchrony in coupled systems
No full textWe investigate the phenomenon of distance synchrony in a system of coupled conservative axially symmetric chaotic oscillators using master–slave type coupling. Our study reveals that the variables of the coupled oscillators achieve synchronization at a constant difference that depends on the coupling strength. This distance synchrony is explored and confirmed with two coupled as well as different types of network topologies. Our findings provide insight into the dynamics of coupled chaotic systems and contribute to the understanding of synchronization patterns in axially symmetric chaotic systems. We also provide analytical support for the numerical findings, along with achieving the same with experiments. This research has potential applications in various fields, including secure communications, neural networks, and other complex systems exhibiting chaotic behavior
Distribution Model Reveals Rapid Decline in Habitat Extent for Endangered Hispid Hare: Implications for Wildlife Management and Conservation Planning in Future Climate Change Scenarios
No full textThe hispid hare, Caprolagus hispidus, belonging to the family Leporidae is a small grassland mammal found in the southern foothills of the Himalayas, in India, Nepal, and Bhutan. Despite having an endangered status according to the IUCN Red List, it lacks studies on its distribution and is threatened by habitat loss and land cover changes. Thus, the present study attempted to assess the habitat suitability using the species distribution model approach for the first time and projected its future in response to climate change, habitat, and urbanization factors. The results revealed that out of the total geographical extent of 188,316 km2, only 11,374 km2 (6.03%) were identified as suitable habitat for this species. The results also revealed that habitat significantly declined across its range (\u3e60%) under certain climate change scenarios. Moreover, in the present climate scenario protected areas such as Shuklaphanta National Park (0.837) in Nepal exhibited the highest mean extent of habitat whereas, in India, Dibru-Saikhowa National Park (0.631) is found to be the most suitable habitat. Notably, two protected areas in Uttarakhand, India, specifically Corbett National Park (0.530) and Sonanandi Wildlife Sanctuary (0.423), have also demonstrated suitable habitats for C. hispidus. Given that protected areas showing a future rise in habitat suitability might also be regarded as potential sites for species translocation, this study underscores the importance of implementing proactive conservation strategies to mitigate the adverse impacts of climate change on this species. It is essential to prioritize habitat restoration, focused protection measures, and further species-level ecological exploration to address these challenges effectively. Furthermore, fostering transboundary collaboration and coordinated conservation actions between nations is crucial to safeguarding the long-term survival of the species throughout its distribution range
Effect of metal fractions on rice grain metal uptake and biological parameters in mica mines waste contaminated soils
No full textHeavy metals from mica waste not only deteriorate the soil quality but also results in the uptake of metals in the crop. The present investigation was conducted to evaluate the effects of different fractions of metals on the uptake in rice, soil microbial and biochemical properties in mica waste-contaminated soils of Jharkhand, India. From each active mine, soil samples were randomly collected at distances of \u3c 50 m (zone 1), 50–100 m (zone 2), and \u3e100 m (zone 3). Sequential metal extraction was used to determine the fractions of different metals (nickel (Ni), cadmium (Cd), chromium (Cr) and lead (Pb)) including water-soluble (Ws) and exchangeable metals (Ex), carbonate-bound metals (CBD), Fe/Mn oxide (OXD) bound metals, organically bound metals (ORG), and residues (RS). The Ni, Cr, Cd and Pb in rice grain were 0.83±0.41, 0.41±0.19, 0.21±0.14 and 0.17±0.08 mg/kg respectively. From the variable importance plot of the random forest (RF) algorithm, the Ws fraction of Ni, Cr and Cd and Ex fraction of Pb was the most important predictor for rice grain metal content. Further, the partial dependence plots (PDP) give us an insight into the role of the two most important metal fractions on rice grain metal content. The microbial and enzyme activity was significantly and negatively correlated with Ws and Ex metal fractions, indicating that water-soluble and exchangeable fractions exert a strong inhibitory effect on the soil microbiological parameters and enzyme activities
Elucidating the synergistic effect of acidity and metalloid poisoning on the microbiome through metagenomics and machine learning approaches
No full textThe abundance and diversity of the microflora in a complex environment such as soil is everchanging. Mica mining has led to metalloid poisoning and changes in soil biogeochemistry affecting the overall produce and leading to toxic dietary exposure. The study focuses on two prominent stressors acidity and arsenic, in mining-contaminated agricultural locations. Soil samples were collected from agricultural fields at a distance of 50 m (zone 1) and 500 m (zone 2) from active mines. Mean arsenic concentration was higher in zone 1 and pH was lower. Geostatistical and self-organizing maps were employed to report that the pattern of localization of soil acidity and arsenic content is similar indicating a causal relationship. Cluster and principal component analysis were further used to materialize a negative effect of soil acidity fractions and arsenic labile pool on soil enzymatic activity (fluorescein diacetate, dehydrogenase, β-1,4-glucosidase, phosphatase, and urease), respiration and Microbial biomass carbon. Soil metagenomic analysis revealed significant differences in the abundance of microbial populations with zone 1 (contaminated zone) having lower alpha and beta diversity. Finally, the efficacy of several machine-learning tools was tested using Taylor diagrams and an effort was made to select a potent algorithm to predict the causal stressors responsible for depreciating soil microbial health. Random Forrest had superior predictive power based on numerical evidence and was therefore chosen as the best-fitted model. The aforementioned insights into soil microbial health and sustenance in stressed conditions can be beneficial for predicting remedial strategies and practicing sustainable agriculture
Evolution of bed-forms due to associated wave turbulence over a sloping sand bed similar to shoaling zone of sea coast – An experimental approach
No full textThis paper presents the impact of near-bed turbulence due to only waves on a sediment bed to analyze the bedform evolutions and formation of ripples over a sloping bed of fine sediments in a laboratory flume. Measurements were made on the development of bedforms and the specific properties related to ripple formations. The geometric characteristics of ripples were recorded at multiple locations along the sloping bed in equilibrium condition. The results offered a significant understanding of the correlation between wave characteristics on a sloping bed and the shape of ripple marks. Grain size distribution analysis along the sloping bed revealed significant changes in the fine, non-cohesive sediment bed. It is interesting to note that the unimodal grain-size distribution was transformed to bimodal due to progressive surface waves. Moreover, strong spatial dependency was observed between the characteristics of waves and the arrangement of ripple forms. The parameters of ripples formed due to surface waves agree well with the predicted formulas. Results of near-bed turbulence due to surface waves are also reported. Furthermore, the study provides an understanding of the intricate relationships between waves, bed morphology, and changes in ripple marks. This knowledge can be applied to improve engineering practices in coastal regions
Fragile futures: Evaluating habitat and climate change response of hog badgers (Mustelidae: Arctonyx) in the conservation landscape of mainland Asia
No full textThe small mammalian fauna plays pivotal roles in ecosystem dynamics and as crucial biodiversity indicators. However, recent research has raised concerns about the decline of mammalian species due to climate change. Consequently, significant attention is directed toward studying various big flagship mammalian species for conservation. However, small mammals such as the hog badgers (Mustelidae: Arctonyx) remain understudied regarding the impacts of climate change in Asia. The present study offers a comprehensive analysis of climate change effects on two mainland hog badger species, utilizing ensemble species distribution modeling. Findings reveal concerning outcomes, as only 52% of the IUCN extent is deemed suitable for the Great Hog Badger (Arctonyx collaris) and a mere 17% is ideal for the Northern Hog Badger (Arctonyx albogularis). Notably, projections suggest a potential reduction of over 26% in suitable areas for both species under future climate scenarios, with the most severe decline anticipated in the high-emission scenario of SSP585. These declines translate into evident habitat fragmentation, particularly impacting A. collaris, whose patches shrink substantially, contrasting with the relatively stable patches of A. albogularis. However, despite their differences, niche overlap analysis reveals an intriguing increase in overlap between the two species, indicating potential ecological shifts. The study underscores the importance of integrating climate change and habitat fragmentation considerations into conservation strategies, urging a reassessment of the IUCN status of A. albogularis. The insights gained from this research are crucial for improving protection measures by ensuring adequate legal safeguards and maintaining ecological corridors between viable habitat patches, which are essential for the conservation of hog badgers across mainland Asia. Furthermore, emphasizing the urgency of proactive efforts, particularly in countries with suitable habitats can help safeguard these small mammalian species and their ecosystems from the detrimental impacts of climate change