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Aiming at the problem that complex security primitives in existing schemes were not suitable for resource-constrained IoT devices, a lightweight efficient anonymous identity authentication protocol for IoT devices was designed based on physical unclonable function (PUF).Through the formal security model and ProVerif tool, it was proved that the protocol satisfies 13 security properties such as information confidentiality, integrity, un-traceability, and forward/backward secrecy.Compared with existing relevant protocols, the computing overhead of the protocol on the device side and the server side is 0.468 ms and 0.072 ms respectively, and the device storage and communication overheads are 256 bit and 896 bit respectively, which is highly suitable for lightweight IoT devices with limited resources.

Rock failure phenomena are accompanied by abundant energy variation, and the energy dissipation can explain the dynamic mechanical characteristics of the rock. In this study, a series of granite specimens (a total of 60) with different aspect ratios were dynamically loaded by a split Hopkinson pressure bar (SHPB) to explain the energy dissipation and the rock-crushing degree under dynamic load. A new index, namely energy time density (wtd), is proposed to evaluate the energy dissipation considering the time factor. The relationships between strain rate, energy time density, and specific energy absorption are analyzed. A metric (Ku) is defined to describe the degree of rock fragmentation quantitatively. The correlations of fractal dimension and Ku with different impact pressures are compared. It was concluded that there is a noticeable peak point in the energy time density curve. The energy time density of the stress equilibrium point is three times that of the peak point. The energy time density declines after the peak point, then the energy consumption density tends to be stable. The linear relationship between strain rate and peak point energy time density is stronger. The new index can describe energy dissipation well under dynamic loading. In addition, the experimental results indicate that the degree of crush Ku can describe the degree of crush, and the effect of fractal dimension to quantify the fracture characteristics of the rocks is less good in this test. The crushing degree of rocks increases with the increase of strain rate. Furthermore, the prediction effect of energy time density is better than that of strain rate about Ku.

Purpose: This study aims to evaluate the predictive efficacy of the C-reactive protein/albumin ratio (CAR), a cost-effective, easily accessible, and reproducible biomarker obtained from standard blood tests, in forecasting acute kidney injury (AKI) among patients undergoing acute pancreatitis (AP). Considering that changes in the CAR are associated with AKI incidence in AP cases, this work aims to explore whether CAR can be used as the innovative, inflammation-based diagnostic marker for AKI in AP patients. Methods: The current retrospective cohort study consecutively enrolled AP patients admitted to First College of Clinical Medical Science of China Three Gorges University during the period from January 2019 to October 2023. Data were extracted systematically in electronic medical records from these hospitalized individuals, including baseline demographic and clinical characteristics. To ascertain the association of the CAR level with the development of AKI, we carried out multivariate logistic regression, adjusting for potential confounders. These confounders were initially identified through univariate regression. Furthermore, the potential effect modifiers in the relationship between CAR and AKI occurrence were explored by stratified logistic regression. Results: Totally, 1514 AP were recruited, including 257 (16.9%) with AKI. CAR was positively correlated with AKI. When adjusting for potential confounders, the AKI risk in patients in the upper CAR tertile (2.628– 22.994) increased by 83% relative to those in lower tertile (0.05– 0.289) (OR 1.83, 95% CI 1.13– 2.96, P = 0.013). The AKI risk tended to increase according to the increasing CAR tertile (P for trend = 0.013). No significant interactions were observed among subgroups based on age, sex, BMI, admission to ICU, hypertension, DM, chronic obstructive pulmonary disease, severity of AP, etiology of AP, demand for CRRT, mechanical ventilation, and blood transfusion (all P > 0.05). Conclusion: A higher CAR is significantly related to the higher AKI incidence in AP patients in the Chinese population. [ABSTRACT FROM AUTHOR]

Counterparty credit risk (CCR) is a significant risk factor that financial institutions have to consider in today's context, and the COVID-19 pandemic and military conflicts worldwide have heightened concerns about potential default risk. In this work, we investigate the changes in the value of financial derivatives due to counterparty default risk, i.e., total value adjustment (XVA). We perform the XVA for multi-asset option based on the multivariate Carr–Geman–Madan–Yor (CGMY) processes, which can be applied to a wider range of financial derivatives, such as basket options, rainbow options, and index options. For the numerical methods, we use the Monte Carlo method in combination with the alternating direction implicit method (MC-ADI) and the two-dimensional Fourier cosine expansion method (MC-CC) to find the risk exposure and make value adjustments for multi-asset derivatives. [ABSTRACT FROM AUTHOR]

When lightning strikes the outgoing lines of a hydropower station， it induces severe overvoltages. Then， the operation of gas-insulated switchgear （GIS） and circuit breakers within the station also triggers very fast transient overvoltages （VFTO）， posing a significant threat to the insulation safety of GIS and transformer equipment. To address this， an ultra-wideband transient voltage sensor is installed on the high-voltage side of the GIS equipment at the main transformer of the hydropower station. This establishes an online monitoring system for transient voltages， capturing the transient response process in the hydropower station during lightning strikes on its outgoing lines. Through the analysis of time domain and frequency domain characteristics of transient voltage， it is observed that when the outgoing lines of the hydropower station experience a lightning-induced ground fault， fracture reignition may occur in the circuit breaker. Based on the waveform of the lightning transient voltage infiltrating the hydropower station， accurate single-end fault location can be achieved. When the lightning strike on lines occurs within 10 km of the hydropower station， the transient voltage infiltrating the station poses a threat to transformer insulation. The ultra-wideband transient voltage monitoring system accurately records abnormal transient events within the hydropower station. Comparative analysis of the time domain and frequency domain characteristics of transient waveforms at various measurement points facilitates the localization of transient excitation sources. This aids in the early detection of equipment anomalies， providing timely warnings and ensuring the reliability of equipment operation and stable hydropower dispatch.

Photocatalytic CO 2 reduction into value-added chemical fuels using sunlight as the energy input has been a thorny, challenging and long-term project in the environment/energy fields because of to its low efficiency. Herein, a series of CdS/Co-BDC composite photocatalysts were constructed by incorporating CdS nanoparticles into Co-BDC using a dual-solvent in situ growth strategy for improving photocatalytic CO 2 reduction efficiency. The composites were characterized through XRD, SEM, TEM, XPS, DRS and EPR techniques in detail. 18% CdS/Co-BDC composites showed superior performance for the photocatalytic CO 2 reduction to CO, which was 8.9 and 19.6 times higher than that showed by the pure CdS and Co-BDC, respectively. The mechanism of enhanced photocatalytic CO 2 reduction performance was analyzed. The CdS/Co-BDC composites showed better adsorption for CO 2 . Detailed analysis of XPS, transient photocurrent responses, and electrochemical impedance spectroscopy (EIS) shows the existence of strong charge interaction between CdS and Co-BDC and the photo-electrons of CdS can be transferred to Co-BDC. Additionally, Co-oxo of Co-BDC plays the role of a redox-active site and promotes the reduction performance via the method of valence transition of Co(ii)/Co(iii) redox., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Mechanical vibrations and solar energy are ubiquitous in the environment. Hereon, we report the synergic enhancement of the oxidation by simultaneously harvesting solar and mechanical vibrations through flexible piezo and photocatalytic composite nanofiber mats. Surface enriched titanium dioxide nanoparticles incorporated in polyacrylonitrile (PAN/TiO 2 ) nanofibers were synthesized using a single pot electrospinning process with well-defined fiber diameters with widely tunable loading density. By incorporating photocatalytic TiO 2 in flexible piezoelectric PAN nanofiber support, piezoelectric fields generated under the mechanical deformation promote the separation of the photogenerated electrons and holes to accelerate oxidation of pollutants. Our results demonstrated that the catalytic activity of PAN/TiO 2 nanofibers in photodegradation of Rhodamine B (RhB) can be greatly enhanced by environmental vibration-induced piezoelectricity of PAN nanofibers, with a maximum enhancement factor of ~2.5. The working mechanism for the enhanced photocatalytic activity of PAN/TiO 2 nanofibers by the mechanical vibrations were attributed to the piezoelectric effect of PAN nanofibers, which could efficiently promote the separation of the photogenerated electrons and holes in the TiO 2 nanoparticles. We believe the approach to enhancing the catalytic activity of mat can make full use of the polymer properties and natural energy, and it also can be extended to other composite polymer/semiconductor systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

During the COVID-19 pandemic, many institutions have announced that their counterparties are struggling to fulfill contracts. Therefore, it is necessary to consider the counterparty default risk when pricing options. After the 2008 financial crisis, a variety of value adjustments have been emphasized in the financial industry. The total value adjustment (XVA) is the sum of multiple value adjustments, which is also investigated in many stochastic models, such as the Heston [B. Salvador and C. W. Oosterlee, Appl. Math. Comput. 391, 125489 (2020)] and Bates [L. Goudenège et al., Comput. Manag. Sci. 17, 163-178 (2020)] models. In this work, a widely used pure jump Lévy process, the Carr-Geman-Madan-Yor process has been considered for pricing a Bermudan option with various value adjustments. Under a pure jump Lévy process, the value of derivatives satisfies a fractional partial differential equation (FPDE). Therefore, we construct a method that combines Monte Carlo with a finite difference of FPDE to find the numerical approximation of exposure and compare it with the benchmark Monte Carlo simulation and Fourier-cosine series method. We use the discrete energy estimate method, which is different from the existing works, to derive the convergence of the numerical scheme. Based on the numerical results, the XVA is computed by the financial exposure of the derivative value.