esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Materials and Methods
### System Design  
The system design, as shown in Figure 1, integrates a Wi-Fi-enabled Internet protocol (IP) camera (TP-Link, Hong Kong), a high-speed Wi-Fi router (TP-Link, Hong Kong), and a desktop server computer (ASUS, Taipei City, Taiwan) equipped with an NVIDIA RTX 3050 graphics processing unit (GPU) (Gigabyte Technology, New Taipei City, Taiwan), an Intel i5 processor (INTEL, Hong Kong) with 12 cores, and 32 GB of random-access memory (RAM) (Micron, Singapore). This setup captures and wirelessly transmits a video stream for real-time processing, including a machine learning model and a privacy-preserving anonymization technique. The processed video stream and elderly status are then securely uploaded to the cloud and made accessible to caregivers through a smartphone application.  
The system begins with an IP camera capturing live video in the living space of an elderly individual, as shown in Figure 2. This video stream is processed using YOLOv8 [60], a machine learning model that identifies the presence of a person in the scene. Once detection occurs, the process splits into two main functions: ensuring the subject's privacy and analyzing their posture for safety concerns.  
Figure 1: The architecture of the proposed surveillance system.  
Figure 2: The flowchart of the proposed system’s working principle.  
To protect privacy, the system employs subject anonymization by using the bounding box information of the detected individual and replacing their visible image with background. This method maintains the individual's privacy by hiding their appearance in the video feed. Concurrently, pose keypoints are extracted using YOLOv8 to form a skeleton representation of the person. This skeleton aids in adjusting the 2D avatar's posture to accurately reflect the person's movements, ensuring a realistic representation.  
The skeleton representation is crucial for the fall detection algorithm, which analyzes the person's movements and posture. If the algorithm detects a pattern indicative of a fall, it immediately triggers an alert for assistance. Finally, the system securely transmits the anonymized video stream, now featuring the 2D avatar, along with any alerts from the fall detection algorithm to the caregiver through the cloud. In the event of a fall, the system sends an alert to the caregiver that includes both the fall alarm and a real-time image of the scene without modifications. This ensures that the caregiver receives comprehensive information about the fall and the actual condition of the monitored person, enabling a prompt response.
# Accounting for Training Data Error in Machine Learning Applied to Earth Observations
## Guidelines and Recommendations
### Step 5. Evaluate and Communicate the Impact of Training Data Error
#### 4.5.1 TD Treatment Tiers
Ideally, this tier should also be followed by the makers of map products intended for widespread public use, who should also release TD and map reference data that were used during map creation [57]. This step would allow users full insight into the quality and usability of the map for their own purposes. Published TD (and map reference data) should be documented with standard metadata, as shown in Table S4, including the relevant error metric associated with each observation. The SpatioTemporal Asset Catalog (STAC, [[https://stackspec.org/](https://stackspec.org/)]([https://stackspec.org/](https://stackspec.org/))) provides a framework for standardization of metadata for EO data and is increasingly seen as an international standard for geospatial data. Tier 2  
If it is not possible to directly measure and quantify TD error, the next best approach to account for TD error is to introduce a plausible range of simulated error into the TD and evaluate its impact on model uncertainty and map accuracy after training separate models with the perturbed datasets [48]. If multiple workers are tasked with collecting TD for the same site, then the variance in their data can be calculated [151] to derive the uncertainty bounds (e.g., Figure 12). This approach is demonstrated in the building mapping case study (Section 3.1.1), which illustrates the sensitivity of key accuracy metrics to two different kinds of simulated labeling errors. The wheat yield case study (see Section 3.3) provides an example of this approach for a continuous variable. This tier may also provide an acceptable standard for both benchmark datasets and publicly released map products, particularly where absolute error quantification is less important, as well as for publicly released map products. TD and map reference data should also be made openly available with standard metadata, as described above, including the uncertainty metric for each observation. If it is not possible to publish them (e.g., because of privacy concerns), then researchers should provide documentation that summarizes these data and their uncertainty. Tier 3  
If the TD error quantification in Tiers 1 or 2 are not possible, then researchers should at minimum publish their TD and map reference data, e.g., [55] with accompanying metadata that includes descriptions of potential errors and uncertainties. If data cannot be made openly available, then researchers should publish full descriptions of the potential error in the data. Adherence to this tier, at least the reporting component, should be the minimal standard practice in peer-reviewed, map-based scientific research.
## 3 Establishment of Ship Emission Calculation Model
### Engine Machine Propeller Matching Coefficient
#### 3.4.2 On-Board Measurement of Marine Diesel Engine Shaft Power  
Due to the large number of ship types and the high testing cost of actual ships, this study selected five representative inland river ships that sail in the region all year round.  
\begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline
**Fuel Type** & **CO** & **HC** & **NO\({}_{\chi}\)** & **PM\({}_{10}\)** & **PM\({}_{2.5}\)** & **SO\({}_{\chi}\)** & **CO\({}_{2}\)** \\ \hline Light diesel & 1 & 1 & 0.94 & 0.17 & 0.17 & 0.04 & 1 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Fuel correction factor (sulfur content 0.1%).  
\begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline
**Type** & \begin{tabular}{l} **CO** \\ **g/kWh** \\ \end{tabular} & \begin{tabular}{l} **HC** \\ **g/kWh** \\ \end{tabular} & \begin{tabular}{l} **NO\({}_{\chi}\)** \\ **g/kWh** \\ \end{tabular} & \begin{tabular}{l} **PM\({}_{10}\)** \\ **g/kWh** \\ \end{tabular} & \begin{tabular}{l} **PM\({}_{2.5}\)** \\ **g/kWh** \\ \end{tabular} & \
\begin{tabular}{l} **SO\({}_{\chi}\)** \\ **g/kWh** \\ \end{tabular} &
\begin{tabular}{l} **CO\({}_{2}\)** \\ **g/kWh** \\ \end{tabular} \\ \hline Main engine & 1.1 & 0.5 & 11.2 & 1.5 & 1.2 & 11.5 & 646.1 \\ \hline Auxiliary engine & 0.9 & 0.4 & 8.2 & 1.5 & 1.2 & 12.3 & 690.7 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Fuel emission factor (2.7% sulfur content).  
Regional ships are mainly cargo ships, so the test objects selected in this paper are mainly cargo ships. The parameter information of the ship is shown in Table 5. The test site was selected as the Three Gorges Reservoir area with gentle water flow and a wide section of the river to ensure that the test results are affected as little as possible by the external hydrological environment. In this study, the resistance strain gauge torque measurement method was used to track and measure the tail shaft power of the diesel engines in real time on five representative ships in the region. The arrangement of the shaft power measuring points is shown in Figure 2.
###### Abstract  
This work designed and implemented a new low-cost, Internet of Things-oriented, wireless smart sensor prototype to measure mechanical strain. The research effort explores the use of smart materials as transducers, e.g., a magnetorheological elastomer as an electrical-resistance sensor, and a cantilever beam with piezoelectric sensors to harvest energy from vibrations. The study includes subsequent and validated results with a magnetorheological elastomer transducer that contained multiwall carbon nanotubes with iron particles, generated voltage tests from an energy-harvesting system that functions with an array of piezoelectric sensors embedded in a rubber-based cantilever beam, wireless communication to send data from the sensor's central processing unit towards a website that displays and stores the handled data, and an integrated manufactured prototype. Experiments showed that electrical-resistivity variation versus measured strain, and the voltage-generation capability from vibrations have the potential to be employed in smart sensors that could be integrated into commercial solutions to measure strain in automotive and aircraft systems, and civil structures. The reported experiments included cloud-computing capabilities towards a potential Internet of Things application of the smart sensor in the context of monitoring automotive-chassis vibrations and airfoil damage for further analysis and diagnostics, and in general structural-health-monitoring applications.  
s mart sensor; magnetorheological elastomer; energy harvesting; piezoelectric; IoT +
Footnote †: journal: Applied Sciences
## 2 Dual-Port MIMO Antenna
### Diversity Parameters
#### 2.5.4 Mean Effective Gain (MEG)  
An important parameter for assessing efficiency of individual elements within a MIMO system, especially in practical multipath conditions. It is calculated using Equation (5) [27]. For consistent and balanced diversity performance, the MEG difference between antenna elements should remain within 3 dB [27]. The difference computed with Equation (6) [27]  
Figure 11: Diversity gain (DG) comparison.  
Figure 12: Total active reflection coefficient (TARC) comparison.  
shown in Figure 13, remains under 0.3 dB throughout the UWB frequency range, indicating that the antenna operates consistently and is well balanced.  
\[\textit{MEG}_{i} =\textbf{0.5}[\textbf{1}-\sum_{j=1}^{N}\mid\textit{S}_{ij}\mid^{2}] \tag{5}\] \[\textit{MEG}_{ij} =\textit{MEG}_{i}-\textit{MEG}_{j} \tag{6}\]
# Comparison of Tutorial Methods in Virtual Reality Games for a Better User Experience
## 6 Discussion
### Analysis of Qualitative Interview Results According to the Tutorial Method  
The interview revealed that the no-tutorial method had the lowest user preference, whereas the instruction-screen tutorial method had the highest. Nonetheless, irrespective of the experimental conditions, most participants responded that they could play the game sufficiently without experiencing motion sickness. Regarding the no-tutorial method, numerous opinions of 'it was difficult to understand the controller intuitively' and 'it was difficult to immers myself in the game because I felt like I was alone in the game' were noted. Conversely, regarding the instruction-screen and context-sensitive tutorials, numerous opinions stating that they were 'helpful in understanding the game method' were noted. Regarding the instruction-screen tutorial, an opinion stating 'it was relatively better than no tutorial because it explained the game method' was noted, alongside 'it was difficult to remember the explanation provided at the start of the game while playing the game' and 'because it is provided at the beginning of the game, the game can be explored more, making it more immersive and interesting'. Regarding the context-sensitive tutorial, opinions that 'it was the best way to learn how to use a game controller, but it was uncomfortable to see because it was provided around designated objects in the game' and 'because tutorials are provided for each user task, the process was well understood and was able to proceed sequentially' were noted. The consensus was that the context-sensitive tutorial was more convenient in terms of explaining the controls, whereas the instruction-screen tutorial was more efficient in explaining the game process. Some users suggested using videos or simulations when providing tutorials and responded that they needed feedback on the buttons they pressed.  
In summary, providing a tutorial is crucial to preventing motion sickness or improving the user experience, even in a simple game. Regarding context-sensitive tutorials, they help users to understand the detailed game progress method at each step; therefore, for an exploration game, an instruction-screen tutorial, which informs only on the progress method, is recommended. Furthermore, for context-sensitive tutorials, the backgrounds or objects in the game must be displayed in positions where they are not covered, whereasfor instruction-screen tutorials, they must be placed in the centre of the screen based on the viewing angle. As both tutorial methods provide a positive user experience, they are both recommended.
## 4 Experimental Results and Analysis
### Assessment of Multi-Rx and Multi-Tx LEO-LEO Occultation Constellation Performance
#### 4.3.2 Performance of Two-Orbit Constellations
For the 9-day global coverage fraction of 12 Rx/12 Tx occultation events, the number of times a single grid is revisited in some areas is more than 70, which is beneficial to the observation of low and middle latitude regions, but cannot 100% cover the Earth. Figure 11: The global coverage of LEO-LEO occultation events for the 2 Rx/2 Tx, 6 Rx/6 Tx and 12 Rx/12 Tx constellations with the Rxi98 and Taxi98 inclination orbital planes, illustrating the occultation numbers per \(5^{\circ}\)\(\times\)\(5^{\circ}\) latitude and longitude grid cell. The GCFs were calculated using grid cell areas according to Equation (12). Figure 12: Accumulated time dependence of the global coverage fraction (GCF) (blue lines) and the occultation event number (orange lines) for the 2 Rx/2 Tx, 6 Rx/6 Tx, and 12 Rx/12 Tx constellations with the Rxi98 and Taxi98 inclination orbital planes. Figure 13: The global coverage of LEO-LEO occultation events for the 2 Rx/2 Tx, 6 Rx/6 Tx, and 12 Rx/12 Tx constellations with the Rxi140 and Taxi40 inclination orbital planes, illustrating the occultation numbers per \(5^{\circ}\times 5^{\circ}\) latitude and longitude grid cell. The GCFs were calculated using grid cell areas according to Equation (12). The global coverage fraction and the number trend of the occultation events for the Rxi140-Txi40 2 Rx/2 Tx, 6 Rx/6 Tx, and 12 Rx/12 Tx constellations are shown in Figure 14. One can see that with the increase in the number of Rx and Tx satellites, the slope of the number curves increases significantly. However, the GCF increases rapidly at first and then remains at a certain level, at which point essentially no more new grid cells start to be covered and, hence, the GCF saturates (and only the number of events in cells already covered increases). Although the number of 10-day 12 Rx/12 Tx occultation events reaches more than 61,000, the maximum GCF is 77%. The 10-day occultation number of the 6 Rx/6 Tx constellation is about 15,000, and the GCF is about 75%. These results indicate that, due to the lower inclinations, the NEO constellations cannot observe the high latitude region.
## 3 Results
### Peroxide Value (PV)  
PV was confirmed to be undetectable in both fresh and dried samples in this investigation. It is a positive sign that represented the good quality of dried products, although  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Characteristics** & **Unit** & **Value** \\ \hline Moisture & g/100 g & 82.4 \(\pm\) 0.5 \\ TPC & mg GAE/g d.b & 5.33 \(\pm\) 0.06 \\ TCC & \(\mu\)g/g d.b & 260.38 \(\pm\) 5.52 \\ AA & mg TE/g d.b & 1.60 \(\pm\) 0.05 \\ PV & meq/kg & Not detected \\ \hline Color parameters & & \\ L* value & & 60.87 \(\pm\) 0.59 \\ a* value & & \(-\)23.11 \(\pm\) 0.96 \\ b* value & & 55.82 \(\pm\) 1.13 \\ \hline \hline \end{tabular}
\end{table}
Table 1: The physicochemical properties of avocado pulp powder obtained by infrared drying.  
the material was rich in lipids, particularly the unsaturated fatty acids, which are highly susceptible to oxidation [34; 35]. The most active site in the structure of unsaturated fatty acids is the unsaturated bond, where autoxidation and enzymatic reactions, the principal mechanisms of lipid oxidation, occur, with the primary products of autoxidation being non-radical products, mainly peroxides and hydroperoxides [36]. Lipoxygenases (LOX) have been shown to catalyze the oxidation of polyunsaturated fatty acids, boosting the initiation and propagation of the free radical chain reaction in lipid oxidation governed by enzymatic reactions [37]. In this study, PV of all dried samples was not detected. Therefore, the lipid oxidation in these samples could be limited during IR drying of avocado pulp. The activity of LOX in avocados was characterized in the study of [PERSON] et al. (2010), which reported that LOX activity decreased considerably at temperatures below 30 \({}^{\circ}\)C and above 40 \({}^{\circ}\)C [38]. As a consequence, the effectiveness of thermal pretreatment and drying at high temperatures (65-80 \({}^{\circ}\)C) inactivated these enzyme groups completely, leading to the termination of the start of the initiation and propagation steps in the free radical chain reactions. In IR drying of avocado pulp, it was indicated that the drying process was completed in a short time (from 35 to 55 min). The results implied that moisture would be quickly removed from the materials; thus, hydrolysis of lipids hardly occurred to release fatty acids, which were the materials in the chain of lipid oxidation.
## 5 Experiments
### Addressing Detection Vulnerabilities  
The primary objective of our proposed method is to enhance the robustness of the embedding scheme against detection attacks. In our previous work [5], the concentrated nature of the embedding locations resulted in a conspicuous border line around the 4 kHz frequency band, as depicted in Figure 1. To mitigate this vulnerability, we introduced two solutions:  
* The random expansion approach involves randomly selecting additional blocks for embedding, thereby dispersing the embedding locations.
* The adaptive expansion approach employs an adaptive algorithm to select blocks with lower estimated distortion for embedding, further obfuscating the embedding pattern.  
Figure 4 illustrates the effectiveness of the adaptive expansion technique in concealing the borderline when the block size \(M\) is set to be 64.  
While the proposed technique effectively addresses spectral statistical analysis, it is important to acknowledge the ongoing evolution of spectrum-based attack techniques.  
Figure 4: Comparison of the spectrum between stego data generated by the method without adaption and with adaption (64 segments): Ja_m5.wav.  
Figure 3: Comparison of the audio quality of our previous work (conventional), random expansion (solution 1), and adaptive expansion (solution 2) with different expansion locations.  
Attack methods analyze audio data's statistical properties and structural characteristics without relying on cover data. By examining frequency components, temporal patterns, and perceptual attributes, these techniques can potentially detect the presence of embedded data. Therefore, continued research and the development of robust watermarking methods are essential to counter evolving detection techniques.
# Multi-Level Elasticity for Wide-Area Data Streaming Systems: A Reinforcement Learning Approach
## 8 Evaluation
### Considerations on the Initial Learning Phase  
From our experiments, the RL-based policies seem to outperform simpler control policies both at the application and infrastructure level. A common issue with RL solutions is the long time often required to learn a good policy, which leads to long initial transitory phases. Model-based approaches try to overcome this issue by exploiting the (partial) available knowledge about the underlying system dynamics [41].  
In Figure 6, we compare the behavior of the system at the beginning of our simulations, with and without RL-based policies for the ICS and the ACS. We can observe that indeed the behavior of the RL-based policies at the beginning is not optimal, but quickly improves after the first 2-3 simulated days of operation. This behavior is also shown in Figure 7, which reports the average cost, computed  
Figure 5: Application response time, number of operator replicas and active computing nodes during five simulated days at the end of the experiments, with different ACS policies (i.e., threshold-based and RL-based), and varying the cost function weights for the ICS RL-based policy.  
according to Equation (1), incurred by the RL-based RM. Indeed, after the end of the first simulated day we cannot observe significant variations in the average cost.  
We should also note that, in practice, we could let E2 DF start with a simple policy, and automatically switch to the RL-based one after the initial transitory phase. Therefore, our solution can be used without worrying about the initial learning phase.
# SDN-Based Secure Common Emergency Service for Railway and Road Co-Existence Scenarios
## 5 Validation of Developed Application for Common Emergency Services  
This section presents the validation of the developed SDN-based application for common emergency services for railway and road coexistence scenarios. Emergency and non-emergency messages are sent for demonstration purposes from Car1 to CarEmer and from Train1 to RailEmer. For validation purposes, these data packets were captured in Wireshark [38].
# A Channel Compensation Technique Based on Frequency-Hopping Binary Offset Carrier Modulated Signal
## 1 Introduction
Our work is contributive in following aspects:  
* To confront occasions according to our background where a considerable Doppler effect frequently occurs, which is difficult for the original OFDM signal to compensate itself by limited pilot-modulated subcarriers, and FH-BOC modulation is adopted due to its outstanding performance on auto-correlation function;
* The most important motivations are to promote the resilience of the designed signal against interferences. Specifically, I/Q modulation offers capability that every interference affects in-phase component also inflicts the same influence on quadrature component. Therefore, certain favorable characteristics of FH-BOC modulation can be exploited for correcting OFDM symbols, in order to demodulate the OFDM signal component effectively and precisely;
* Instead of using conventional pilot-based OFDM signal, we take an OFDM signal in which each symbol consists entirely of data-modulated subcarriers into implementation, and a quadrature component FH-BOC signal oversees the providing of channel estimation and valid compensation for the OFDM symbols. Hence, this way allocated a spectrum that can be utilized more efficiently, and the throughput capacity, compared to the original OFDM system, is improved consequently. The remainder of this paper is organized as follows. Section 2 demonstrates diagrams of both the transmitter and receiver and provides an overview of our proposed signal process. Section 3 conducts a performance analysis of the designed system by discussing details, along with the characteristics and benefits through such implementation. Section 4 provides simulation results to illustrate improvements of the designed system in the correlating aspects. Finally, Section 5 draws the conclusions.