esa-sceva/satcom-chunk-collection huggingface dataset:
# Spatial Multiplexing Holography for Multi-User Visible Light Communication
## 4 Experimental Setup
### Signal Processing  
Figure 7b illustrates the BPL-DMT modulation and demodulation process, integral to the experimental setup. The BPL process is bifurcated into two main stages: signal-to-noise ratio (SNR) estimation and bit power loading. Initially, QPSK (quadrature phase shift keying) modulation signals are dispatched to ascertain the channel's SNR. This involves mapping all subcarriers with the QPSK signal, followed by DMT modulation application.  
In accordance with a predetermined SNR table, the bit allocation for each DMT-modulated subcarrier is computed. The total count of subcarriers stands at 1024, which includes 512 signal carriers along with their conjugate symmetries, thereby establishing Hermitian symmetry. To accommodate the low-frequency portion of the signal, zero-padding is employed, involving eight subcarriers. Subsequently, the signal undergoes upsampling by a factor of two.  
Employing the Levin-Campello (LC) algorithm, we optimize the allocation of bits to each subcarrier, ensuring that the bit error rate (BER) remains within the acceptable range for the 7% forward error correction (FEC) BER threshold (\(3.8\times 10^{-3}\)) under a predefined power budget. This optimization strategy aims to maximize spectral efficiency and data rate while adhering to stringent error rate constraints.  
In this experiment, multiple user profiles were simultaneously loaded, forming a frequency-division multiplexing communication system through the use of OFDM. However, time-division multiplexing is also feasible if the refresh rate of the SLM can meet the requirements of time-varying signal transmission.
## 5 The Proposed Linear Multi-Hop Analytical Model
Considering one day of transmissions and the two abovementioned sensor types, Table 1 shows the energy costs. Based on this, we used 2 dBm in the proposed model to reduce the energy cost. Finally, to identify the throughput limitation, we compute the maximum number of packets that can be transmitted (_Tpackets_) [11] using the ToA and the following equation:  
\[TH=\ sample\ rate\times payload \tag{2}\]1  
where n is the number of channels, and d is the duty cycle, which is 1% (36 s per hour). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Sensor Type** & \multicolumn{4}{c}{**Temperature Sensor**} & \multicolumn{4}{c}{**Pressure Sensor**} \\ \hline No. Packets (packet/day) & \multicolumn{4}{c}{8} & \multicolumn{4}{c}{24} \\ \hline Transmission Power (dBm) & 2 & 8 & 14 & 20 & 2 & 8 & 14 & 20 \\ \hline Total Energy per Day (MJ) & 7.5 & 7.53 & 7.56 & 8 & 60 & 60.24 & 60.48 & 61.44 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Energy costs for different LoRaWAN transmission power and different sensor types.
## 3 Research and Development Methodology
### Software Architecture  
The software architecture of _Ana_ chatbot, detailed in Figure 2, comprises of several modules:  
* **Domain Abstract Ontology:** Is the schema of the general ontology with domain independent concepts, able to be instantiated for each particular authority. This ontology refers to public information, such as deadlines, student opportunities and educational offer.
* **Specific Ontology:*
* represents concepts which belong or are particular to a specific candidate, be it country origin, last courses taken. The ontology is structured in three sub-ontologies, namely:
* _Public information:_ refers to information for public use, such as number of available seats, specialisation etc.
* _Adaptive information_ is still general information, but provided to the candidates based on their profile, e.g., different countries issue different documents related to graduation (Abitur, Bacalaureate, GMAT etc.), depending on bilateral agreements, foreigners have access to education based on various fees. This adaptive feature is highly recommended by inclusive communication guidelines [29].
* _Personal information_ is closely related to the candidate and contains a significant amount of personal data which falls under GDPR regulations: data related to birth and identity, grades, medical certificates and educational options. Therefore strict access policies will be in place, both technically as well as administratively.
* **AI Engine:** includes the algorithms used in processing the knowledge acquisition, and modeling correct answers for the candidates. This module makes the connection between the two parties of the conversation, respectively feeds the candidate with very specific, personalized, and accurate information from the ontology. Moreover, the information is explained, so that the candidate has no doubt about the accuracy and conformity of the knowledge which is provided. This module is also able to learn based on user interaction and feedback so that the chatbot improves its knowledge, responsiveness, and usability with each conversation.
* **Knowledge Acquisition:** collects information from different sources such databases, cloud, documents, other software, and local data.  
Of course, the _Ana_ chatbot security is paramount as any university must protect the privacy of the candidates, respectively the personal data and preferences. That has to be done not only for GDPR compliance but also because people need to trust the _Ana_ chatbot and the University of Medicine and Pharmacy \"[PERSON]\" as well. The security is structured on three levels: (1) data security which regards the safety and reliability of the data, database and data flow; (2) ontology security which focuses on the consistency accuracy and quality of the ontology; (3) third party security which assures a proper, correct and responsible integration of the _Ana_ chatbot with other applications.
## 3 Bioactivity of _Chlorella vulgaris_ Compounds
### Antioxidant Activity
#### 3.1.2 Enzyme-Promoted Antioxidants  
In addition to its non-enzyme-promoted antioxidants, _C. vulgaris_ contains polysaccharides that support the body's natural antioxidant defenses by stimulating key antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT). These enzymes play a vital role in ROS neutralization by converting superoxide radicals into less harmful molecules. The mechanisms by which SOD and CAT alleviate oxidative stress are well established: at the cellular level, SOD catalyzes the dismutation of superoxide anions (O\({}_{2}\)\({}^{-}\)) into oxygen and hydrogen peroxide, reducing oxidative stress, while CAT further breaks down hydrogen peroxide into water and oxygen, mitigating its potential to harm cellular structures like proteins, lipids, and DNA. For instance, Tsiplakou et al. [62] reported a notable increase in SOD (10.31%) and CAT (18.66%) activities in the blood plasma of goats supplemented with _C. vulgaris_, highlighting its potential to enhance the antioxidant defense mechanisms in livestock. Similarly, Sikiru et al. [63] demonstrated that _C. vulgaris_ supplementation in pregnant New Zealand White rabbits led to improved antioxidant enzyme activities, thereby reducing oxidative stress markers such as malondialdehydedehyde. These findings are corroborated by Panahi et al. [64], whose studies have shown that the antioxidant properties of _C. vulgaris_ extend to human health, with clinical trials indicating its potential to reduce oxidative stress markers in smokers. Moreover, the anti-inflammatory and immunomodulatory properties of these polysaccharides further protect against oxidative stress and inflammation, particularly in the brain [54; 59]. This dual action of enzyme-promoted antioxidants and non-enzyme-promoted antioxidants highlights the comprehensive antioxidant capability of _C. vulgaris_, supporting its therapeutic potential in various health applications.
## 5 Results Analysis
### Simulation Results for Scenarios 1-5
#### 5.2.2 Resilience Loss
Scenario 1: partial closure of the north tube (only one lane is closed); Scenario 2: complete closure of the north tube and use of the adjacent one for bi-directional traffic with the traffic by-pass opening within 10 min (Scenario 2a), 20 min (Scenario 2b), and 30 min (Scenario 2c), respectively; Scenario 3: partial closure of the north tube with alternative itinerary used by HGVs only; Scenario 4: complete closure of the north tube and use of the adjacent one for bi-directional traffic with alternative itinerary used by HGVs only, and traffic by-pass opening within 10 min (Scenario 4a), 20 min (Scenario 4b), and 30 min (Scenario 4c), respectively; Scenario 5: complete closure of the north tube with alternative itinerary used by all the vehicles. Smaller resilience losses were found with the partial closure of the tube (i.e., Scenario 1) in contrast with the complete one. In the event of the complete closure of the north tube, the resilience loss that is related to the traffic flow on the motorway from the Nodes A to D was computed to be smaller when the traffic by-pass is opened within a time of 10 min from the start of the incident (i.e., Scenario 2a against the Scenarios 2b, and 2c). From Figures 7-9, it can also be noted that when the alternative itinerary is activated for HGVs only, both in the case of the partial (i.e., Scenario 3) and complete closures (i.e., Scenarios 4a, 4b, and 4c) of the north tube, minor resilience losses are computed when compared to those of the corresponding scenarios (i.e., respectively 1, 2a, 2b, and 2c) with reference to the motorway section from A to B and passenger cars only. Greater resilience losses were found when the north tube is completely closed and all the traffic flows (i.e., both passenger cars and HGVs) are redirected to the alternative itinerary of Figure 2. It is to be noted that the resilience losses found are coherent with the aforementioned delay times.
## 2 Application of the Proposed Work  
E-health solutions are best suited for remote health monitoring of elderly citizens and ailing or disabled persons living in old age homes, pandemic-hit areas, or who have any other hindrance in interacting with medical staff [2]. Moreover, e-health platforms can deliver optimum results in situations where increased physician and patient engagement, improvements in clinical quality, use of evidence based medication, and lower medical expenditures are required [8]. Recent commercial e-health platforms based on AI-enabled health devices, mobile health tracking, telemedicine, patient portals, and blockchain electronic health records include Vantage Health, Doctor-on-Demand, Practo, Inside Tracker, Precision Nutrition, etc. [40]. An illustration of the proposed OBAN based on FSO wireless technology is shown in Figure 1. FSO is an optical communication technology that uses light beams propagating in free space to wirelessly transmit data for telecommunication purposes [2]. It can provide increased capacity and cost efficiency while maintaining high data rates comparable to optical fiber-based links. FSO offers large license-free spectrum utilization, immunity to EMI, and high security [2]. FSO technology has the potential to resolve the main issues of large installation cost and time consumption typically associated with optical fiber-based systems [2]. However, FSO links can be affected by various disturbances, as discussed above [2].  
In the proposed system, different on-body sensors for measuring critical physiological parameters such as body temperature, pulse rate, cough, blood pressure, electrocardiogram (ECG), electroencephalogram (EEG), oxygen saturation level, blood glucose level, etc., are mounted on the bodies of patients. All sensors are directly connected to an optical coordinator. The coordinator is located at a fixed position in the patient's room. It encodes signals from the sensors using the proposed 2D-spectral/spatial DW-ZCC code, then the combined optical signal is transmitted over the FSO channel towards the medical center. On the receiving side, the optical signal is decoded, then data from each sensor are recovered via photodetection for analysis by medical staff, as shown in the Figure 1. It is clear that FSO technology can help to provide a low cost alternative for implementing the proposed OBAN, thereby resolving the issues associated with RF-based counterparts discussed in the previous section. Moreover, data privacy, multiple access, and cancellation of MAI are achieved using the proposed 2D-spectral/spatial OCDMA.
## 3 Results
### Effects of CWP on Concrete Mechanical Properties
#### 3.2.2 Effects of Curing Age on the Mechanical Properties of CWP Concrete
Although the pozzolanic reaction of CWP is initially slower, it becomes increasingly effective with extended curing, particularly after 28 days, resulting in concrete with satisfactory or even improved mechanical performance over conventional concrete in long-term applications.
## 3 Methodology
### Description of Representative Infrastructure
This communication is typically facilitated via Ethernet LAN or optical links, but there is an option for a cellular modem backup when needed. The RTU is adept at retrieving data from various substation devices, notably protective relays and power quality meters. When it comes to LBS, the RTU ensures remote and local control of the switch, provides 3-phase voltage and current readings, and detects faults on power lines. An advanced  
Figure 1: Considered representative interconnected infrastructures of power and communication networks in a Smart Grid domain. feature includes initiating automatic functions, notably disconnecting after identifying a short circuit during a voltage-free pause, as well as the regulation of blocking conditions.
## 5 Conclusions  
The current work aimed to study the use of the Vilnius chaos oscillator in digital communication systems for internet of things (IoT) applications with enhanced physical layer security. Vilnius oscillator was selected due to the circuit's simplicity and low power consumption, thus providing an opportunity for application in wireless sensor networks (WSN) and IoT. The paper analyzed the performance of frequency-modulated chaos shift keying (FM-CSK) and chaos phase-shift keying (QCPSK) in the channel with selective fading and the case of phase noise in comparison with the non-chaotic counterparts of these systems: frequency-shift keying (FSK) and quadrature amplitude modulation (QAM).  
The study of selective fading and additive white Gaussian noise (AWGN) impact on the performance of the systems showed that QCPSK demonstrates a lower degradation of BER performance on notch than 4-QAM, while FM-CSK and FSK had a similar degradation dynamic. The analysis of the system's performance limits in the case of phase noise and AWGN demonstrated that the levels of phase noise affecting the performance of the QCPSK are sufficiently higher than that of the 4-QAM. In turn, FSK and FM-CSK showed comparable levels of phase noise which causes performance degradation.  
Thus, the results of both studies showed that the dynamic of the performance degradation of chaotic communication systems is more resistant to channels with selective fading or in the case of phase noise, thus demonstrating the advantages of using chaotic waveforms for IoT communication systems in addition to increased physical layer security.  
**Author Contributions:** Formal analysis, R.B., D.C. and F.C.; Funding acquisition, A.L.; Investigation, R.B. and D.C.; Methodology, D.K. and A.L.; Software, R.B. and D.C.; Supervision, D.K. and A.L.; Validation, D.K. and J.G.; Visualization, R.B., D.C., F.C. and J.G.; Writing--original draft, R.B., D.C. and F.C.; Writing--review & editing, F.C., D.K. and A.L. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work has been supported by the European Social Fund within the Project No 8.2.2.0/20/1/008 <<Strengthening of PhD students and academic personnel of Riga Technical University and BA School of Business and Finance in the strategic fields of specialization>> of the Specific Objective 8.2.2 <<To Strengthen Academic Staff of Higher Education Institutions in Strategic Specialization Areas>> of the Operational Program <<Growth and Employment>>. This work has been supported by the Riga Technical University 2021/2022 project for strengthening scientific personnel capacity Nr. ZM-2021/1, <<FPGA-based chaotic wireless communication system>>, Nr. ZM-2021/2, <<QCPSK communication system\" and Nr. ZM-2021/3, <<FM-CSK communication system\".  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.
## 4 Conclusions  
The article solves the important scientific and technical task of developing and experimentally confirming the adequacy of the developed calculation methodology and ensuring the course stability of the universal earthmoving machine in the process of digging the soil:  
1. The calculation scheme for determining the power load of the UEM with a two-link system of lateral supply of the operating equipment to the face in the mode of digging the soil with maximum productivity has been substantiated and developed for the first time. The dependencies to define the external forces that determine the machinery course stability in the translational and rotational supply mode of the actuator have been obtained.
2. The factors whose change determines the value of the loading on the UEM operating equipment in the mode of digging the soil have been determined. These include the width and the depth of the excavation under construction, the speed of the longitudinal motion of the machinery along the face, the speed of the lateral supply to the face of each of the two links of the operating equipment, the soil strength according to the hummer of the Ukrainian State Road Scientific and Research Institute, and the duration of the intermediate frame rotation of the operating equipment at the end of each half-cycle of the operating process.
3. The mathematical models of the power loading of the UEM operating equipment and for determining the machinery course have been created in the process of digging the soil. They are based on taking into account the physical features of the digging process in the mode of translational and rotational supply of the rotor actuator to the face. It enables the calculation of the machinery course stability in the operating mode with sufficient accuracy.
4. The developed method for determining the stability of the UEM course can be used when creating the industrial samples of trenching earthmoving machinery.
## 3 Key Findings
### RQ2: What Kinds of Learning Algorithms Are Being Deployed Towards the Security of IIoT?
#### 3.2.4 RQ2-2: Set of Available Datasets Used by Learning Models for IIoTsec
Both datasets possess seven attack categories each, and they were taken from normal and abnormal observations in the ICSs laboratories [49]. The WST dataset had a preprocessed network transaction data of 236,180 samples when it was collected from the testbed at Mississippi State University's critical infrastructure protection center for 25 h [88]. Of these, 172,415 are normal, and 63,764 are malicious values. The researchers used a bump-in-the-wire approach to gather data logs and inject attacks into Modbus communication. The dataset is also identified with 24 features. On the other hand, the GP dataset contains a collection of labeled Modbus/RTU telemetry systems in a total of 10,619 observations via the critical infrastructure protection center at Mississippi State University. Of the total observations, 6672 are normal and 3947 are malicious values. GP dataset possesses 27 features. Table 4 shows other information on IIoT-centric datasets, such as evaluated attacks.
## 3 Results and Discussion
### Tensile and Compressive Strength  
Strength is the most important parameter for judging the mechanical properties of the composite materials. Figure 12 illustrates the variation in strength with the weight fraction of Si\({}_{3}\)N\({}_{4}\) particles in the composite materials. The base alloy matrix exhibits distinct ultimate tensile and compressive strengths of 154 MPa and 302 MPa, respectively. However, these strengths increase to 231 MPa and 425 MPa, respectively, when 9 wt.% of reinforcement is added. It is noteworthy that materials with higher strength also tend to have higher hardness. The strength values obtained in this study are comparable to earlier findings [5,6]. The increase in strength of the composites can be attributed to the presence of hard reinforcement particles. The reinforced particles introduce residual stress, which can be either compressive or tensile in nature. This stress hinders the movement of dislocations, thereby strengthening the material. Additionally, the presence of reinforcements in the matrix leads to grain refinement, resulting in a reduction in grain size. Furthermore, the strength of the material can be explained by the Hall-Petch equation represented in Equation (4).  
\[\sigma=\sigma_{0}+\frac{K}{\sqrt{d}} \tag{4}\]  
where \(\sigma=\) final yield strength;  
\(\sigma_{0}=\) initial/original yield strength;  
\(d=\) average grain diameter of particle;  
\(k=\) strengthening constant, which depends on the material.
# Value-Added Use of Waste PET in Rubberized Asphalt Materials for Sustainable Payement
## 1 Introduction
Hence, the recycling of PET-based waste plastics in building asphalt pavement is undoubtedly an optional pathway for a large amount of consumption. With regard to relevant studies, there have been some publications that mainly focused on directly adopting waste PET slices or powders as modifiers or alternatives of fine aggregates to upgrade the overall performance properties of asphalt binders and mixes [30; 31; 32; 33]. As a result, the bonding characteristic between the binder and aggregates is still the most focused-on point that determines the moisture damage resistance and long-term properties of asphalt mixtures, and is thus needed to be strengthened further for the goal of better field applications. For this, the authors made an attempt to chemically convert these wastes into functional value-added additives for modifying bitumen and confirmed that they are useful and effective to improve the adhesion of binders to aggregates [34; 35]. However, the engineering performances of asphalt materials, especially mixtures, with the incorporation of PET additives, were not validated in detail in previous studies. To fill this research gap, a new method of collectively using PET additives and crumb rubber as performance-enhancing modifiers for asphalt pavements will be employed in this study to investigate the engineering performances of rubberized asphalt materials. To achieve the research objectives, the superpave high- and low-temperature properties of a rubberized binder modified by PET additives were first characterized through dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. Then, the engineering performances of the further fabricated mixtures, including the Marshall stability, rutting resistance, fatigue resistance, and dynamic modulus, were validated through a Marshall test, a Wheel Tracking Test (WTT), an Indirect Tensile Fatigue Test (ITFT), and a Simple Performance Test (SPT). Figure 1 presents the flowchart of the research plan of this study.