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Physical Layer Identity Authentication Technology for Broadband Power Line Communication Equipment
No full textHigh speed power line carrier communication systems are increasingly exposed to security threats, including device identity forgery, data tampering, and unauthorized intrusion. To address these challenges, this study introduces an identity authentication technology based on physical layer characteristics. This approach leverages the unique hardware attributes of the signal precursor code and the distinct features of the power line channel to construct a singular identity fingerprint for each device. This technique can effectively deter adversaries from counterfeiting the identity of legitimate devices, thereby enhancing the security of power line communication systems. The efficacy of this proposed method has been validated within an experimental high-speed power line carrier communication system environment. Furthermore, the performance of this approach under varying channel conditions has been thoroughly analyzed. These findings offer fresh insights and a novel technical framework for bolstering the physical layer security of power line carrier communication systems
Electromagnetic Excitation for Blade Vibration Analysis in Static Conditions: Theoretical Insights and Experimental Evaluation
Get PDFBlade vibration testing is crucial for understanding the dynamic behavior of rotating machinery. This article presents a theoretical analysis and experimental validation of electromagnetic excitation for blade vibration testing in static conditions. The study focuses on investigating the effect of electromagnets on static blades to establish a theoretical foundation. The Timoshenko beam theory is utilized to analyze the vibration parameters, including amplitude and frequency while considering associated uncertainties. The theoretical analysis is complemented by numerical modeling using the finite-element method and experimental measurements employing laser Doppler vibrometer (LDV). The results demonstrate the effectiveness of electromagnetic excitation in generating controlled vibrations in static blades. These findings provide valuable insights and serve as a basis for subsequent investigations into the behavior of blades during rotation. The mathematical model’s frequency estimation error was approximately 4% compared to numerical results, and the numerical amplitude results differed by 6.4% from the experimental measurements. These contributions enhance the understanding and design of blade vibration monitoring systems in rotating machinery and provide valuable information on the blade’s dynamic parameters for the calibration of blade tip timing (BTT) systems
Intelligent airborne monitoring of man-made marine objects using Machine Learning techniques - Part II
Get PDFThe objective of this study is to create a new platform for the automated detection of irregularly shaped man-made marine objects (ISMMMOs) in large datasets derived from marine aerial survey imagery. Readers may recall that we published the first part of the paper in October issue. We present here the concluding par
Oscillation frequencies of moderately rotating delta scuti stars: asymmetric mode splittings due to non-spherical distortion
Get PDFWe find that the observed pressure-mode rotational splittings of slowly/moderately rotating Scuti stars and Cephei stars mostly have a positive asymmetry. That is, the left frequency spacing is larger than the right spacing in the dipole mode splitting triplets and the mode splitting multiplets (considering modes only). This is in agreement with the second-order perturbative effect of the rotational non-spherical distortion: both the prograde and retrograde modes have their frequencies shifted towards lower values relative to the modes. We thus study the rotational perturbation both in the first and second order, as well as the near-degeneracy mode coupling effect in MESA models representing Scuti stars. For faster rotators, the near-degeneracy mode coupling between the nearest radial and quadrupole modes can significantly shift the modes, reduce the splitting asymmetry, and even change its sign. We find the theoretical splitting asymmetry from the second-order non-spherical distortion can explain the observed asymmetry quantitatively. To facilitate future detections, we predict correlations between splitting asymmetry, splitting amplitude, and pulsation frequency. We also discuss additional factors that can influence splitting asymmetry, including embedded magnetic fields, resonant mode coupling, and binarity
Re-imagining Schooling from the Perspectives of Marginalized Children and Young People: Balancing Children’s Rights and Rights Claims Alongside the Expectations of Parents and Governments
No full textAntimicrobial peptides from frogs of the Glandirana genus
Get PDFGlandirana is a genus of frogs that includes G. rugosa, G. emeljanovi, G. minima, G. tientaiensis, G. susurra, G. nakamurai and G. reliquia. These frogs produce antimicrobial peptides (AMPs), which are endogenous antibiotics that possess antibacterial, antifungal, antiviral and anti-endotoxin activity and help keep the hosts free from infections. In these activities, microbial death is promoted by membranolytic mechanisms that are mediated by the cationic charge and amphiphilic α-helical structures of these peptides. In general, these peptides are selective for microbes, showing low levels of haemolytic and cytotoxic activity, as well as possessing other biological activities, including anticancer, antioxidative and insulinotrophic action. In this review, a brief overview of AMPs, with a focus on those from amphibians is provided, along with the phylogeny and nomenclature of frogs and AMPs from the Glandirana genus. This review then provides a comprehensive, in-depth description of the antimicrobial and other biological activities of all AMPs produced by known frogs of the Glandirana for the period 1994 to 2024. This description includes a detailed discussion of structure / function relationships and mechanisms involved in the membrane interactions that drive these biological activities, with comparisons between AMPs from the same frog and between frogs across the genus. Based on their biological properties, AMPs from frogs of the Glandirana genus have been proposed for investigation as potential therapeutic agents, such as in the treatment of cancers and diabetes, as well as antimicrobial agents in areas, including crop protection, the food industry and oral hygiene
Integrating Anthropological Science in Archaeological Practice: The Importance of Spatial Data
Get PDFThe excavation of human remains is a critical aspect of archaeology, and mortuary context forms a considerable portion of the archaeological record investigated by archaeologists. However, the scientific analysis of human remains is frequently limited to post-excavation, meaning that archaeological data is rarely integrated into the interpretation of human remains.
This paper examines the contribution of anthropological science during excavation using one specific class of data – spatial position – in order to understand how information on location affects the interpretation of human remains in archaeological contexts. Examining the utility of spatial information of human remains excavated from a mass grave at the site of Başur Höyük, near Siirt, Türkiye, we propose that spatial or location data collected at the level of the individual element is necessary to reconstruct the circumstances and actions in respect of the creation and formation of the studied mass grave
Rainfall erosivity assessment over a flooding basin, Kelani River basin, Sri Lanka
Get PDFThis study evaluates the rainfall erosivity (RE) and erosivity density (ED) over the Kelani River basin, Sri Lanka for a period of 31 years (1990–2020). The river basin is well known for its annual floods during the southwestern monsoon season and severe erosion including landslides can be observed. The catchment was analyzed for its RE using the Wischmeier and Smith algorithm and for its ED using Kinnel's algorithm. The monthly rainfall data spreading over the river basin were used to analyze the monthly, seasonal, and annual RE and ED. Interestingly, the annual RE showed a linear increasing trend line over 31 years, and a maximum value of 2,831.41 MJ mm ha−1 h−1 yr−1 was able to be observed in the year 2016. The RE peaks in May which is in the southwestern monsoon season. This reveals that the risk of soil erosion in the basin is high in the southwestern monsoon season. In addition, land use and land cover changes over the years have adversely impacted the erosion rates. Therefore, it is highly recommended to investigate soil erosion in-depth and then implement relevant regulations to conserve the soil layers upstream of the river basin