esa-sceva/satcom-chunk-collection huggingface dataset:
# Numerical Analysis of Cyclic Impact Damage Evolution of Rock Materials under Confining Pressure
## 2 Numerical Modeling and Verification  
### SHPB Fundamentals  
SHPB (split Hopkinson pressure bar) apparatus is a widely employed equipment to investigate the dynamic mechanical properties of rock materials. A SHPB apparatus comprises an impact bar, an incident bar, a transmission bar, and an energy absorption device. During a SHPB test, the rock specimen is sandwiched between the incident bar and transmission bar. Axial pressure and confining pressure loading systems are incorporated with the SHPB apparatus to achieve combined dynamic and static loading.  
By collecting incident wave \(\epsilon_{i}(t)\) and reflected wave \(\epsilon_{r}(t)\) on the incident bar and transmitted wave \(\epsilon_{t}(t)\) on the transmission bar, the stress-strain relationship of the rock specimen can be determined according to the classical two-wave method.  
\[\epsilon(t)=\frac{c_{0}}{l_{0}}\int_{0}^{t}\left[\epsilon_{i}(t)-\epsilon_{r} (t)-\epsilon_{t}(t)\right]dt=-\frac{2c_{0}}{l_{0}}\int_{0}^{t}\epsilon_{r}(t)dt \tag{1}\]\[\sigma(t)=E\epsilon_{t}(t) \tag{2}\]  
where \(E\) and \(c_{0}\) are the elastic modulus and wave velocity of steel pressure bars, respectively, and \(l_{0}\) is the length of the rock specimen.  
During cyclic impact tests, a half-sine incident stress wave can effectively maintain a constant loading strain rate and ensure stress uniformity within the specimen during deformation [28; 29]. In numerical simulations, the half-sine incident stress wave can be achieved by using initial velocity through a spindle-type impact bar or applying half-sine stress waves at the front end of the incident bar [30]. In this study, the half-sine incident wave is directly applied at the front end of the incident bar. The fitting formula of the half-sine incident stress wave is shown in Equation (3).  
\[P_{d}(t)=\begin{cases}P_{max}\Big{[}\frac{1}{2}-\frac{1}{2}\text{cos}(2\pi \omega t)\Big{]}&(t\leq 1/\omega)\\ 0&(t>1/\omega)\end{cases} \tag{3}\]  
where \(P_{max}\), \(\omega\) and \(t\) are amplitude, angular frequency, and duration of the half-sine incident stress wave, respectively.  
In this study, considering the physical and mechanical properties of rock, the amplitude of half-sine incident stress wave is taken as 170 MPa, 180 MPa, and 190 MPa.
_J. Sens. Actuator Netw._**2014**, \(3\), 224-244; doi:10.3390/jsan3030224  
_Journal of Sensor and Actuator Networks_  
**ISSN 2224-2708**  
www.mdpi.com/journal/jsan  
_Article_  
**Evaluation of Secure Multi-Hop Node Authentication and Key Establishment Mechanisms for Wireless Sensor Networks**  
**[PERSON] \({}^{1,2}\), [PERSON] \({}^{1,2,\ast}\) and [PERSON] \({}^{1,2}\)**  
\({}^{1}\) Clermont Universite, Universite d'Auvergne, LIMOS, BP 10448, F-63000, Clermont-Ferrand,  
France; E-Mails: [EMAIL_ADDRESS] (I.M.); [EMAIL_ADDRESS] (P.L.)  
\({}^{2}\) CNRS, UMR 6158, LIMOS, F-63173 Aubbiere, France  
* Author to whom correspondence should be addressed; E-Mail: [EMAIL_ADDRESS]; Tel.: +33-4-73-17-70-48; Fax: +33-4-73-17-71-11.  
_Received: 12 June 2014; in revised form: 25 August 2014 / Accepted: 26 August 2014 / Published: 3 September 2014_  
**Abstract:** Designing secure authentication mechanisms in wireless sensor networks in order to associate a node to a secure network is not an easy task due to the limitations of this type of networks. In this paper, we propose different multi-hop node authentication protocols for wireless sensor networks. For each protocol, we provide a formal proof to verify the security of our proposals using Scyther, which is an automatic cryptographic protocols verification tool. We also provide implementation results in terms of execution time consumption obtained by real measurements on TelosB motes. These protocols offer different security mechanisms depending on the design of the protocol itself. Moreover, we evaluate the overhead of protection of each solution by studying the effect on execution time overhead of each protocol. Finally, we propose a mechanism to detect possible attack based on our evaluation results.  
**Keywords:** authentication; wireless sensor networks; security; overhead of protection; multi-hop; formal verification
## 2 Materials and Methods
### Inclusion and Exclusion Criteria  
To ensure that the selected articles met criteria of high quality and relevance, precise selection and exclusion parameters were defined. The review included articles that:  
1. Were written in English, as it is the predominant means of communication in the scientific field, selecting works for a detailed analysis that could adequately cover the themes of AI adoption. Both open-access publications and those accessible through subscription or academic libraries were considered, with an emphasis on open-access sources to facilitate broader accessibility.
2. Presented empirical studies on factors driving AI adoption in the healthcare sector, with the aim of focusing on research offering significant contributions and insights. This criterion was aimed at identifying studies that provide a deep understanding of the drivers behind AI integration in healthcare contexts.  
3. Were published in scientific journals or recognized conference proceedings, to encompass a broad spectrum of research contributions. This inclusion was further refined to articles published between 2019 and 2023, and limited to works available in scientific journals or conference proceedings, ensuring the inclusion of the most current and high-quality information.
4. Fell within the subject areas of computer sciences, social sciences, business management and accounting, and economics, econometrics, and finance, reflecting a multidisciplinary approach to understanding the multifaceted impact of AI on healthcare management.  
Articles that did not conform to these standards were excluded, particularly those not in English due to language limitations, or those that, while addressing related topics, did not specifically focus on factors of AI adoption in hospital management, in order to maintain focus on the central themes of the review. This methodology aimed to ensure the inclusion of significant and relevant contributions, limiting the scope to high-quality and accessible sources, to provide a comprehensive and in-depth overview of AI's impact on healthcare management.
utilization of nanoparticles can be seen in the modern field of medicine. Gold nanoparticles are the most impactful material in nanomedicine and nanoscience. They are being used as photovoltaic agents, radio infections, drug carriers and contrast agents. In addition, there are many properties of gold and silver nanoparticles that are attractive for use in biomedical diagnosis and treatment. The treatment of arterial diseases using nanoparticles is still under development. [PERSON] et al. [6] investigated blood flow through stenosed vessels and presented results for different flow parameters. They concluded that by adding gold nanoparticles, the velocity of blood increases and they also compared their results to Cu and TiO\({}_{2}\) models. A number of researchers [7; 8; 9; 10] have paid attention to the study of arterial diseases by applying different methods.  
Blood vessels are important components in the circulatory system. The primary objective of the blood circulatory system is to transport oxygen and important nutrients to active body tissues and remove waste products. The dynamics of blood flow play an important role in the expansion and formation of cardiovascular diseases. Cardiovascular diseases are responsible for the majority of deaths in underdeveloped countries. One of the most serious and common arterial diseases is arterial stenosis. An arterial stenosis blocks the flow of blood and also affects blood pressure. It is a progressive disease that affects up to 2.5 million people over the age of 75. The main causes, symptoms and complications of stenosis are:  
\begin{tabular}{c c c} \hline
**Causes** & **Symptoms** & **Complications** \\ \hline Birth defects, build-up of calcium, radiation therapy and rheumatic fever. & Chest pain, heart palpitations, swollen ankles or feet and difficulty in walking short distances. & Stroke, heart failure, blood clots, arrhythmias and endocarditis. \\ \hline \end{tabular}  
For problems related to physiological flows, the computational fluid dynamics (CFD) tool has become useful over recent years. The main purpose of CFD is to numerically simulate the motion of fluid and heat transfer by using computational prowess. [PERSON] et al. [11] examined the solutions to problems governing equations numerically by using COMSOL. [PERSON] et al. [12] studied the heat transfer consequences for laminar and unsteady fluid flow through distinct elliptic cylinders and found the maximum and minimum values for temperature, pressure and velocity.  
In this article, the behavior of blood flow through a stenosed region is studied. We assumed blood to be a Newtonian fluid because blood shows Newtonian nature in large cavities, veins and arteries. The law of conservation of mass, momentum and energy were solved using COMSOL Multiphysics software and the results were calculated for the velocity, temperature and pressure of the blood flow inside the affected region by utilizing CFD. This article introduces the mathematical study of the addition of gold and silver nanoparticles into the blood flowing through a stenosed region in order to investigate that how hybrid NPs can help in improving blood flow.
## 4 Network Simulation
Additionally, it can be observed from experimental results that the success rate of L-class data packet requests is slightly higher than that of H-class data packets, which reflects the faster key updating rate of the BB84 protocol as compared to the MDI protocol. When the request interval exceeds 200 ms, the performance of APR approaches that of CPSR-HQKDN, which is mainly due to the device foundation built by the idle period-supplemented key pool construction. However, this also incurs greater deployment costs and increased facility construction pressure. Figure 7: Relationship between average packet loss rate and packet request time interval. As shown in Figure 10, the success rate of all schemes exhibits a decreasing trend followed by fluctuations during the dynamic simulation time. This is because in the simulated environment, the key pool is first filled with a sufficient number of keys before sending out data packet requests, which prolongs the overall network lifespan. However, there is a certain gap between the capacity of the key pool and the total key demand of data packets at a request interval of 50 ms, resulting in an inability to fulfill key replenishment within the request interval and leading to a decrease in the success rate. As the simulation time continues to increase, the success rate gradually fluctuates within a certain range. In terms of the success rate, CPSR-HQKDN achieves at least a 16% performance improvement compared to the APR-QKDN and KL-SPRA schemes. Figure 8: Overall packet loss rate of the network as a function of simulation time. Figure 9: Relationship between packet request success rate and request time interval. As shown in Figure 11, the key utilization rates of CPSR-HQKDN, APR-QKDN, and KL-SPRA significantly increase with the simulation time, and their trends are similar. This is because, initially, the amount of keys used is not sufficient to reach a stable standard, leading to a decrease in the key utilization rate due to packet loss. The CPSR-HQKDN scheme has several advantages over the other schemes in terms of the key utilization rate. It offers an approximately 7% improvement compared to APR-QKDN and around a 15% improvement compared to KL-SPRA.
# Polystyrene-Sepiolite Clay Nanocomposites with Enhanced Mechanical and Thermal Properties
## 3 Results and Discussion
### Dynamic Mechanical Analysis (DMA)
#### 3.5.2 Loss Modulus (E\({}^{\prime\prime}\))  
The loss modulus (E\({}^{\prime\prime}\)) is the amount of energy loss upon heating in response to the viscoelastic behavior of the material [54]. Figure 7b indicates the variation in the E\({}^{\prime\prime}\) of pristine PS and nanocomposites with temperature in the range of 25 to 150 \({}^{\circ}\)C at a constant frequency of 1 Hz. Initially, at low temperature, the E\({}^{\prime\prime}\) of pristine PS (S0) was high; however, it decreased with the loading of the filler from 1 wt.% to 4 wt.% in S1, S2 and S4 due to better interfacial adhesion at the matrix-filler interphase, which is attributed to the semi-crystalline nature inducing greater stiffness and hardness. However, as the temperature increased up to \(T_{g}\) of PS, the value of E\({}^{\prime\prime}\) in the nanocomposites greatly increased as compared to pristine PS because of internal molecular frictions at the matrix-filler interphase, which caused a hindrance in material flow, dissipating more energy in terms of force [55]. It was further observed that the E\({}^{\prime\prime}\) decreased exponentially in the glass transition phase by observing a sharp peak as the material turned viscous in the rubbery region.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Sample Formulation**} & **Tensile Strength (TS)** & **Young’s Modulus (E)** & **Elongation at Break** \\  & **Mpa** & **Gpa** & **(E\({}_{\mathbf{b}}\)) \%** \\ \hline
**S0** & 38.74 \(\pm\) 0.3 & 3.03 \(\pm\) 0.02 & 2.16 \(\pm\) 0.06 \\ \hline
**S1** & 41.69 \(\pm\) 0.4 & 3.11 \(\pm\) 0.06 & 1.99 \(\pm\) 0.07 \\ \hline
**S2** & 44.91 \(\pm\) 0.6 & 3.82 \(\pm\) 0.24 & 1.79 \(\pm\) 0.06 \\ \hline
**S4** & 46.29 \(\pm\) 0.5
# Model-Based Analysis and Improvement of Vehicle Radiation Emissions at Low Frequency
## 2 Problem Description
### Balance between Performance, Engineering Application and Costs  
Even if the main factors contributing to the vehicle radiation problem are identified technically, it is still not enough to determine the final solution in production because this also depends on their application difficulties and costs. Such untechnical factors are hard to evaluate quantitatively and the final decision is mostly made based on subjective experience. This may cause an ineffective design and increased validation costs. To deal with the aforementioned difficulties, the proposed process for model-based diagnosis and development of vehicle radiated emissions is depicted by Figure 1.  
The advantages of this process are:  
1. The complete vehicle radiation problem is divided into multiple submodels by: 1. The shielding effect of such metal structures as vehicle body, component shell, etc.; 2. The electrical size of the modeled components.
2. The modelling difficulty of each subsystem is comparatively reduced. Moreover, different subsystems can be modelled by different methods. How to decouple the vehicle radiation problem is discussed in Section 3.1.
3. The multi-port network characterized by Z-parameter is adopted to describe the internal couplings of subsystems caused by the near field and electromagnetic radiation. It is not necessary for the engineer to extract the equivalent vehicle radiation model exactly. The final interference is obtained by solving an algebraic equation including  
Figure 1: Model based analysis and improvement process.  
the functions of multi-port networks and their connection topologies. Compared with the 3D numerical method, this reduces the requirement of computational resources greatly. The topological model for vehicle-level radiated emissions is introduced in Section 3.2.
4. The influences of different technical factors on radiated emissions are evaluated quantitatively and directly base on the model by considering their sensitivities and contributions. The engineer need not provide possible improvement measures in advance. The details of the evaluation process can be found in Section 4.1.
5. The tree structure is suggested to model all factors including both technical and untechnical ones, which influence the determination of final solutions. Only the comparative importance among different factors belonging to the same category need to be evaluated by the engineer. This is easier to implement in practice and reduces the requirement of engineer's experience. The model-based improvement process is discussed in Section 4.2.
## 4 Results
### Methodological Approaches  
Regarding methodological approaches, we observed that 74.91% (n = 119) of all papers involve self-reported data collection, 64.60% (n = 104) behavioral, and 10.56% (n = 17) psycho-physiological data.  
Over half of the papers triangulated different types of data (55.28%, n = 89). Thereby, 44.72% (n = 72) of the papers triangulated behavioral and self-reported data. Less common is the triangulation of self-reported, behavioral and psycho-physiological data (6.21%, n = 10). The combination of behavioral and psycho-physiological data (n = 5), or self-reported and psycho-physiological data (n = 2) is even more rarely applied. A large portion of the papers (44.72%, n = 72) is working with only  
Figure 4: Frequencies (\(n\)) of age groups as used in the analyzed automated driving studies.  
one type of data. These papers use mainly self-report measures (27.95%, n = 45), while 16.77% (n = 27) of the papers report exclusively behavioral data.  
Overall, we identified n = 22 different collection methods. The self-defined questionnaire is the most frequently used method (51.85%, n = 84) in AD research papers. This is in accordance with the large number of self-reported data collection. Standardized questionnaires (44.44%, n = 72) and TOR performance (37.65%, n = 61) are frequently used as well. Eye tracking/gaze behavior (24.07%, n = 39), driving performance measures (22.22%, n = 36), interviews (16.05%, n = 26) and secondary task/NDRT performance (8.64%, n = 14) are used more seldomly. Furthermore, rarely applied collection methods are special techniques such as heart rate variability (3.70%, n = 6), think aloud (2.47%, n = 4), probing, electroencephalography (EEG) and detection tasks (each 1.85%, n = 3), UX curve, sorting, electromyography (EMG), and galvanic skin response (GSR; each 1.23%, n = 2). Methods only used once are near infrared spectroscopy (NIRS), focus group, facial expression detection, and matching tasks. Details of the applied methods are described in the following section.
# Recent Progress on Underwater Wireless Communication Methods and Applications
## 1 Introduction
RF communication offers the potential for higher data throughput but is constrained to very short ranges due to significant signal attenuation in seawater, along with challenges in hardware miniaturization and energy efficiency [14; 15; 16]. This limits its application mainly to shallow water scenarios. Optical wireless communication, on the other hand, has emerged as a promising mid-range solution, capable of supporting high-speed, low-latency links, particularly when advanced optical modulation and beam-forming techniques are employed [13; 17]. More recently, biologically inspired mechanisms--such as electric field-based communication inspired by weakly electric fish--have garnered attention for their robustness and low energy consumption, making them especially suitable for operation in turbid and cluttered underwater environments [18]. However, despite the significant advancements in underwater wireless communication technologies, the relevant studies are reported across diverse and fragmented sources, which poses a challenge for researchers and engineers seeking a coherent understanding of the field. Therefore, a timely and systematic review is essential to consolidate existing knowledge and provide guidance for future research and development. In this review, we focus on the following three core aspects:  
1. Comparative analysis of mainstream underwater wireless communication methods: We summarize the characteristics, limitations, and research outlooks of acoustic, electromagnetic, and optical communication technologies, highlighting their performance under different environmental conditions and identifying their most suitable application scenarios. 2. Integration strategies for multi-modal underwater communication: We explore how combining multiple communication modalities can overcome the limitations of individual methods, thereby enhancing communication robustness, supporting intelligent decision-making, and enabling cooperative behavior in underwater robot clusters. 3. Emerging trends and innovative directions in underwater communication: We discuss recent developments such as biologically inspired communication mechanisms and AI-assisted adaptive protocols, which represent promising frontiers in the evolution of next-generation underwater wireless communication systems. The remainder of this paper is structured as follows. Section 2 introduces the key features, research progress, and typical applications of major underwater communication methods. Section 3 discusses the limitations of single-mode communication systems and the development of multimodal approaches. Section 4 presents emerging trends and frontier research topics before the conclusion.
## 4 Results and Discussion  
### Data Analysis  
After collecting data from the different participants, the data were analyzed. The significance values (\(p\)) that the Shapiro-Wilk and Kolmogorov-Smirnov test produced for this study's data were less than 0.05, meaning that data are not normally distributed, as shown in Table 3. All the \(p\)-values in these five elements of CL were less than 0.05 in both tests across three instructional media. A non-parametric Kruskal-Wallis H test was applied to the rest of the data to analyze, which is more appropriate for the non-normally distributed data.