esa-sceva/satcom-chunk-collection huggingface dataset:
# Efficient GPU Implementation of the McMurchie-Davidson Method for Shell-Based ERI Computations
## 5 Implementations in Graphics Processing Unit (GPU)
### Proposed CUDA Block and Thread Mapping Strategies
#### 5.2.2 Basis-Thread Mapping (BTM)  
Similarly to the approach in BBM, the Basis-Thread Mapping (BTM) computes the Basis-ERI in Algorithm 1. However, it differs from the former in that BTM assigns a Basis-ERI computation to one thread. Concretely speaking, each thread performs GTO-ERIs through Algorithm 2 serially. To show the basic idea of thread assignment behind the BTM approach, Figure 8 illustrates a basic example of the parallel thread assignment of CUDA blocks and CUDA threads to the Basis-ERI computation in BTM. The reader may note the relevant roles of Algorithms 1 and 2 in the construction of the components. Compared with BBM, thread assignment appears at first glance to be computationally inefficient due to the large amount of computation in each thread. However, when the target system is small, specifically, when the number of GTOs in the basis functions is small and/or when the azimuthal quantum number is small, BTM is a method that can utilize computational resources efficiently. Similarly to BBM, the Basis-ERI computation is independent of other CUDA threads, and no conflicts of memory access occur when storing the results.
# Spatial Multiplexing Holography for Multi-User Visible Light Communication
## 2 Design Principle of Spatial Multiplexing Hologram
### Spatial Multiplexing Hologram for Multi-User Power Allocation
To accommodate users at different distances \(z\), we generate Fresnel lens plates with a corresponding focal length \(f\), described by the following equation [24]:  
\[F(\xi,\eta,f)=\text{exp}\bigg{[}-\frac{j\pi}{\lambda f}\left(\xi^{2}+\eta^{2} \right)\bigg{]} \tag{5}\]  
Introducing an initial weight column vector \(\mathbf{w}\) for these electrical fields, the SMH can be articulated as  
\[H_{mux}=(\mathbf{H}\cdot\mathbf{F})\times\mathbf{w} \tag{6}\]  
Leveraging the SMH for reconstructing user information in three-dimensional space via Fresnel diffraction, the projection at a z-plane is given by  
\[E_{Res}(x,y,z)=\frac{\text{exp}\Big{(}\frac{j2\pi}{\lambda z}\Big{)}}{j\lambda z }\iint H_{mux}\text{exp}\bigg{\{}\frac{j\pi}{\lambda z}\Big{[}(x-\xi)^{2}+(y- \eta)^{2}\Big{]}\bigg{\}}d\xi d\eta \tag{7}\]  
The relative power received by a user at the z-plane, \(p(z)\), is then determined by  
\[p(z)=\iint\limits_{s}E_{Res}(x,y,z)E_{Res}^{*}(x,y,z)dS \tag{8}\]  
where \(S\) represents the area of the user's receiver aperture. From this, we can derive a vector representing the real power received by all users at different locations, normalized as follows:  
\[\mathbf{p}=\frac{\Big{[}p_{1}\quad p_{2}\quad\ldots\quad p_{n}\Big{]}}{\text{max }\Big{[}p_{1}\quad p_{2}\quad\ldots\quad p_{n}\Big{]}} \tag{9}\]  
Owing to diffraction effects and optical losses, the initial weights \(\mathbf{w}\) may fail to achieve the intended power distribution. Consequently, we employ an optimization strategy to identify the optimal initial weight vector \(\mathbf{w}\), which satisfies the target power distribution at the users' receivers. The optimization is formulated with objectives and constraints as follows [25]:  
\[\min\frac{1}{N}\sum\limits_{i}^{N}(p_{i}-p_{i,i})^{2} \tag{10}\] \[\left\{ \begin{array}{l}0\leq w_{1},w_{2},\ldots,w_{n}\leq 1\\ 0\leq p_{t,1},p_{t,2},\ldots,p_{t,n}\leq 1\end{array} \right.\]  
In this study, we utilize genetic algorithm (GA) to achieve precise power allocation among users, demonstrating the efficacy of our proposed method in a VLC system setting. The GA method is implemented using MATLAB's Global Optimization Toolbox in our work.
# Developing a Fire Monitoring System Based on MQTT, ESP-NOW, and a REM in Industrial Environments
## 3 Methodology
### Radio Environment Mapping  
This study develops and implements a REM framework designed to enhance network coverage, minimize packet loss, and optimize the placement of nodes and relay points in industrial settings. REM construction was carried out in Rooms 502 and 522 of the Electrical Engineering Building at the University of Ulsan, South Korea, labeling them Workspace 1 and Workspace 2, respectively. To systematically collect data, the system  
Figure 3: Application of fire detection using YOLOv5 on the Raspberry Pi 4 module.  
leverages the TurtleBot3 Burger, a mobile robot integrated with a suite of sensors and systems for autonomous navigation and data acquisition [26]. The TurtleBot3 Burger is equipped with a Raspberry Pi single-board computer, an OpenCR embedded controller, a 360-degree LDS-02 LiDAR sensor, an Inertial Measurement Unit (IMU), and an encoder. The Hovermap HF1 mobile LiDAR 3D scanner was deployed with the TurtleBot3 to provide precise 2D environment mapping, further supporting the Simultaneous Localization and Mapping (SLAM) algorithms for enhanced spatial awareness [27]. Figure 4 shows the TurtleBot3 and Hovermap HF1.
# Data and Knowledge-Driven Bridge Digital Twin Modeling for Smart Operation and Maintenance
## 4 Spatiotemporal Data Collection and Processing for Bridge Digital Twin
### The 3D Point Cloud Data Collection and Processing
#### 4.2.1 The 3D Point Cloud Data Collection  
The acquisition of high-precision three-dimensional (3D) geometric data is critical for bridge structural assessments, and LiDAR technology is widely employed for this purpose. LiDAR sensors emit laser pulses and calculate distances to surfaces by measuring the time of pulse returns, producing high-density point cloud data. Depending on the size  
Figure 5: The 3D point cloud data collection and processing [36; 37; 38].  
and characteristics of the bridge, two primary methods are utilized for data acquisition: UAV-mounted LiDAR systems and stationary rack-mounted laser scanners.  
For large-span bridges, such as suspension or cable-stayed bridges, UAV-mounted LiDAR systems are deployed to capture detailed geometric data. These systems enable comprehensive multi-angle scans, particularly for hard-to-access areas, including the underside of decks and tall piers [31]. Flight paths are carefully designed using pre-assigned coordinates to ensure complete coverage of critical structural components, such as piers, decks, and girders. The flight altitude and scan frequency are calibrated to meet the resolution requirements of complex structures. Additionally, UAV-mounted systems are equipped with GPS and inertial measurement units (IMUs), which provide accurate positioning and orientation data to ensure spatial alignment of the collected point cloud.  
For smaller or medium-sized bridges, particularly those located in urban environments, stationary 3D laser scanners mounted on racks are typically employed. These scanners are strategically placed around the bridge to capture precise geometric details without requiring UAVs. Rack-mounted systems are particularly advantageous in settings where UAV operation may be constrained by regulatory or environmental factors, such as in densely populated urban areas.  
The data collection process generates extensive high-density point cloud datasets that capture key geometric features of the bridge, including cracks, surface irregularities, and localized damage. To produce a unified 3D model, point cloud data from different perspectives are aligned using advanced registration algorithms, ensuring spatial consistency and completeness. This processed point cloud data form the foundation for subsequent applications, including geometric modeling, deformation analysis, and structural health monitoring.
# Real-Time Extensive Livestock Monitoring Using LPWAN Smart Wearable and Infrastructure
## 1 Introduction
Secondly, we intend to virtually reduce the distance between the animals and the shepherds. For this reason, it is necessary to relay the positions and statuses of the animals in real time. As the selected area has no guaranteed coverage from any TSP, it has been necessary to focus on a different approach. Our proposal is a wearable equipped with inertial sensors, GNSS and wireless communications. Including adaptive analysis and VQ compression model in the wearable achieving high compression ratios with good peak signal-to-noise ratios (PSNR) [39] allows for real-time monitoring and logging of cattle's position and activities. We have chosen a transceiver with both FSK and LoRa capabilities. As it has been mentioned before, there is no coverage by TSPs and links based on these modulations have proven its utility in open farming scenarios. We focused our electronic design on achieving very low energy consumption, allowing for several months of battery runtime. We have evaluated both the wearable and the system performance for tracking cows in real scenarios, such as mountains and forest. The rest of the paper is structured as follows: first, the characteristics of the wearable, its capabilities and the operation modes are defined; then, laboratory experimentation and field tests are presented; and lastly, system characteristics and work results are discussed.
# Smart Contract-Enabled Secure Sharing of Health Data for a Mobile Cloud-Based E-Health System
## 9 Conclusions  
This study suggests a new EHR sharing strategy that utilizes cloud-based services and blockchains. We highlight the major shortcomings of existing EHR sharing platforms and provide cost-effective solutions through a real-world simulation experiment. This project aims to provide a reliable access control system that relies on a smart contract to regulate access rights and ensure efficient and reliable EHR information exchange. We implemented an Ethereum blockchain only on the AWS cloud to evaluate the effectiveness of the suggested solution; healthcare organizations can interface with both EHR-centralized repositories through the created mobile application. To accomplish secure information management and sharing, we combined the peer-to-peer review process to integrate seamless storage solutions using a blockchain. Compared with traditional approaches, the operational results show that our architecture could require doctors/users to transmit medical information in an adequate and accurate fashion through mobile cloud settings. Our access control system can efficiently detect and block unlawful access to e-health systems, ensuring patient confidentiality and computer security. We provided security analyses and assessments of the technological contributions of the proposed system, demonstrating the benefits of our approach over existing alternatives. Our distributed ledger system is a milestone towards the efficient management of e-health information in portable computing, which would be interesting across many smart healthcare systems.  
Conceptualization, P.C. and A.A.; methodology, M.K.; validation, A.A; resources, J.C.B.; data curation, A.A.R. and A.K.; writing--original draft preparation, P.C. and A.A.; writing--review and editing, M.K. and A.A.R.; visualization, J.C.B.; supervision, P.C., J.C.B. and M.K.; project administration A.A., J.C.B. and A.K. All authors have read and agreed to the published version of the manuscript.  
This research work is funded by the Deanship of Scientific Research under grant number W44-83, Jazan University, Saudi Arabia.  
Not applicable.  
The authors extend their appreciation to the Deanship of Scientific Research at Jazan University in Saudi Arabia for funding this research work through the grant number W44-83.  
The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{l c c c c c c} \hline
**Parameters** & [15] & [16] & [18] & [22] & [12] & **Proposed System** \\ \hline Flexibility & NA & NA & NA & NA & Y & Y \\ \hline Availability & NA & NA & NA & Y & Y & Y \\ \hline Access Control & NA & Y & NA & Y & Y & Y \\ \hline Identity Access & Y & Y & Y & Y & NA & Y \\ \hline Authentication & Y & Y & Y & Y & Y & Y \\ \hline Data Privacy & Y & Y & Y & Y & Y & Y \\ \hline Integrity & Y & Y & Y & Y & N & Y \\ \hline \end{tabular}
\end{table}
Table 2: Performance evaluation comparison with existing methods.
## 1 Introduction
Nowadays, it is known that multiple molecular mechanisms are involved in the formation of persistent bacteria such as the stringent response molecule(p)ppGpp, stress response, SOS response, quorum sensing, toxin-antitoxin (TA) systems, efflux pumps, the ROS response and energy metabolism, among others [11]. The involvement of TA systems in cell physiology, specifically in: (i) biofilm formation by regulating fimbriae [13; 14], (ii) bacterial persistence, by generating slowly-growing cells tolerant to antibiotics and environmental changes [15; 16; 17; 18; 19], (iii) plasmid maintenance [20; 21], (iv) general stress response [22], and (v) phage inhibition [23; 24; 25] is becoming clearer [18]. A TA system is a module of two genes encoding a stable toxin and an unstable antitoxin. Under normal growth conditions the antitoxin inhibits the toxin, but under stress conditions the antitoxin is degraded, leaving the toxin free to inhibit the basic cellular processes like DNA replication or protein synthesis, and also promoting plasmid maintenance, slow growth and latency [18]. These systems are widely distributed and found in the bacterial chromosome, plasmids, and bacteriophages [2]. In this context, this study provides a better comprehension of the molecular mechanisms associated with chlorhexidine adaptation (CA) in two clinical strains of _K. pneumoniae_, both of which produce carbapenemase: ST258-KPC3 (high-risk clone carrying \(\beta\)-lactamase KPC3) and ST846-OXA48 (low-risk clone carrying \(\beta\)-lactamase OXA48), from a phenotypic and transcriptomic point of view. It should be noted that international high-risk clones of _K. pneumoniae_ are among the most common nosocomial pathogens. The success of these clones is due to their facility to spread their plasmids, which carry a considerable variety of antimicrobial resistance genes [26; 27]. Thus, the study of this type of clones is of great clinical relevance. Moreover, this study aims to characterize a new toxin-antitoxin system (PemIK) located in a plasmid inside the ST846-OXA48 CA strain, and to examine the possible role of this system in persistence and in biofilm formation.
# Dynamic Analytical Solution of a Piezoelectric Stack Utilized in an Actuator and a Generator  
[PERSON]  
1 School of Civil Engineering, North China University of Technology, Beijing 100144, China; [EMAIL_ADDRESS]  
[PERSON]  
2  
[PERSON]  
3 School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China; [EMAIL_ADDRESS]  
Correspondence: [EMAIL_ADDRESS]; Tel.: +86-010-623  
insufficiencies in designing the integrated performance of piezoelectric stack devices. For example, in the electromechanical impedance model [40], the piezoelectric stack was first treated as a monolithic element to solve the mechanical properties. Then, it was treated as multiple individual wafers and the middle values of every wafer were approximately adopted to calculate the electrical properties. In the single degree of freedom model [32], the piezoelectric stack was simplified as a spring-mass system to calculate the power output. These two models adopted the spatially constant assumption in the electric field, and did not involve the continuity of displacement and stress between the two layers, which do not reflect the inner electromechanical coupling behavior of the piezoelectric stack. To give accurate theoretical guidance for designing the piezoelectric stack, an improved theoretical model is of great significance.  
Piezo-elasticity theory has been successfully used to study piezoelectric composite structures, including piezoelectric curved actuators [51; 52], multi-layer piezoelectric cantilever [4; 6] and cement-based piezoelectric composites [15; 53], functionally graded piezoelectric beams [54; 55], and laminated piezoelectric hollow spheres [56]. In addition, assuming the electric field to be spatially varying rather than spatially constant is more accurate for describing the electric field [57; 58], which is still not well-applied in the analysis of piezoelectric stacks. These advantages of the methods can effectively supplement existing theories about the piezoelectric stack.  
This study aims to obtain the dynamic analytical solution of the piezoelectric stack utilized in an actuator and generator based on the linear piezo-elasticity theory. The remaining sections are organized as follows: the basic equations for piezoelectric stacks are given in Section 2; in Section 3, by using the displacement method, the dynamic analytical solutions of two different kinds of piezoelectric stacks under external load are derived; in Section 4, the dynamic analytical solutions are verified using the results from other related experimental investigations, and the effects of load frequency and load amplitude on the dynamic characteristics of the stacks are investigated; finally, some conclusions are provided in Section 5.
# Harnessing the Potential of Emerging Technologies to Break Down Barriers in Tactical Communications
## 4 Use Cases
### Use Case 3: Medical Exucuation--MEDEVAC  
This scenario is based on a system for transporting wounded combatants from one location to a specialized hospital. Evacuations are generally carried out in air vehicles used as \"air ambulances\", which have everything necessary, such as specialized health personnel and first aid material, to transfer the patient as quickly as possible to the specialized hospital. It is vital in these platforms to keep fast and efficient communications to guarantee patient safety. In the context of this MEDEVAC scenario, certain 5G technologies, such as IoT devices or wearables, hold potential applications, for instance, smart clothing incorporates sensors (wearables) capable of measuring parameters like temperature, heart rate, or blood pressure. This enables the real-time monitoring of soldiers' health with a high degree of accuracy. The gathered data can be directly transmitted to specialized doctors for personalized follow-up, enabling early diagnosis and prompt evacuation when necessary. Depending on the specific functions to be monitored, these wearables can be integrated into helmets or glasses for head-worn applications, worn as bracelets on the wrist, or integrated into garments, like T-shirts. Additionally, they can even be applied as electronic tattoos on the body.
###### Abstract  
In recent times, visible light communication is an emerging technology that supports high speed data communication for wireless communication systems. However, the performance of the visible light communication system is impaired by inter symbol interference, the time dispersive nature of the channel, and nonlinear features of the light emitting diode that significantly reduces the bit error rate performance. To address these problems, many environments offer a rich infrastructure of light sources for end-to-end communication. In this research paper, an effective routing protocol named the modified grasshopper optimization algorithm is proposed to reduce communication interruptions, and to provide alternative routes in the network without the need of previous topology knowledge. In this research paper, the proposed routing protocol is implemented and analyzed using the MATLAB environment. The experimental result showed that the proposed routing protocol adapts to dynamic changes in the communication networks, like obstacles and shadows. Hence, the proposed protocol achieved better performance in data transmission in terms of throughput, packet delivery ratio, end-to-end delay, and routing overhead. In addition, the performance is analyzed by varying the number of nodes like 50, 100, 250, and 500. From the experimental analysis, the proposed routing protocol achieved maximum of 16.69% and minimum of 2.20% improvement in packet delivery ratio, and minimized 0.80 milliseconds of end-to-end delay compared to the existing optimization algorithms.  
communication network; grasshopper optimization algorithm; optimal routing; visible light communication; wireless ad hoc network +
Footnote †: journal: Physics Letters A
# SAM-PAY: A Location-Based Authentication Method for Mobile Environments +
###### Abstract  
Wireless, satellite, and mobile networks are increasingly used in application scenarios to provide advanced services to mobile or nomadic devices. For example, to authenticate mobile users while obtaining access to remote services, a two-factor authentication mechanism is typically used, e.g., based on the ownership of a personal mobile phone, device, or (smart)card and the knowledge of a (static) username and password. Nevertheless, two-factor authentication is considered roughly \"adequate\" for security problems encountered today on the Internet and even less for ubiquitous or mobile environments. To increase the authentication level, several authentication methods of different classes may be combined to achieve more reliable user identification. In particular, location technologies allow ubiquitous applications to better exploit the (physical) location information in the authentication process. Consequently, in security applications based on multiple authentication factors, an additional authentication factor could be the location information protected for integrity against undesired modification. We present the SAM-PAY authentication method, which combines different authentication factors to obtain a more reliable user identification. The mechanism is based on the use of a (location-aware) device, the location information certified by a trusted external party, such as a component or element in a telecom network, and the knowledge of data, like a static PIN and a dynamically generated one-time password. We also describe the design and implementation of a real case scenario exploiting our SAM-PAY method, namely the refueling service at a self-service gas station. The test-bed put in place for this service demonstrates the feasibility and effectiveness of the SAM-PAY method in open mobile environments.  
a Article  
D. [PERSON], [PERSON] SAM-PAY: A Location-Based Authentication Method for Mobile Environments.  
Electronic 2025146211. [[https://doi.org/10.3390/electronics14030621](https://doi.org/10.3390/electronics14030621)]([https://doi.org/10.3390/electronics14030621](https://doi.org/10.3390/electronics14030621))
## 3 Methodology
### Selection of Probability Distributions  
In this study, continuous probability distributions, namely Weibull (3-parameter and 2-parameter), exponential (2-parameter and 1-parameter), lognormal, normal, gamma, and Generalized-Gamma (G-gamma) distributions were used for modeling the TTF data to obtain best-fit probability distributions and reliability analysis. The key characteristics of  
Figure 3: Block diagram of an HVAC system.  
these distributions are summarized in Table 3. The Weibull distribution is widely used because of its versatility, and an exponential distribution is used for its simplicity. The probability distribution should be selected based on the particular failure mechanism's data distribution, if it is known. Otherwise, identifying the best-fit probability distribution for the given dataset is essential to accurately make reliability predictions and obtain insights from the failure characteristics. It also helps to decide the reliability testing strategies and maintenance policies. The design modifications and selection of alternate components that can be used under stated operating conditions can then be made. The reliability model will help predict failures that will help minimize failure cost, carry out effective maintenance, optimize spare provision, shorten repair times, and improve organization expectations.