esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Electric Propulsion System Characterization  
The characterization of EPU can be performed in several ways [26; 27]. In this research, the characterization was performed based on the obtained three series of static maps. The characterization is necessary for the proper selection of propulsion components, further analysis of the electric propulsion system, and could be a starting point for propulsion system parameters optimization. The characterization procedure can be divided into two parts wherein the first mechanical quantities are considered in the form of aerodynamic forces and moments with respect to the angular velocity of the rotor, and in the second electrical quantities, i.e., electricity consumption.
## 1 Introduction
By spatially following the remaining noise through the multi-head self-attention mechanism, the system estimates the noise level of the signal samples, ultimately improving diagnostic performance in noisy environments. Experimental results have verified the effectiveness of this system. [PERSON] et al. [24] proposed a modular rolling bearing fault diagnosis method based on capsule networks and multi-head self-attention mechanisms. By combining the translational invariance of capsule networks with the embedding attention mechanism of compressors, the completeness of information is ensured. The zero-shot training method introduced achieves cross-domain and imbalanced sample fault diagnosis. Experimental results demonstrate that this method effectively addresses the issues of cross-domain diagnosis and sample imbalance. [PERSON] et al. [25] proposed a fault diagnosis method based on extended convolution, bidirectional gated recurrent units, and multi-head attention mechanisms for achieving rapid and accurate fault diagnosis. This model achieved high prediction accuracy on two different datasets with varying levels of Gaussian noise, indicating its potential in practical applications of early fault diagnosis of bearings. [PERSON] et al. [26] proposed a multi-head attention-based encoder network combined with a dynamic alarm threshold method for fault detection in gearboxes. Field data validated the effectiveness of this method, significantly reducing false alarm rates and improving detection accuracy. Therefore, to further enhance the model's feature extraction and fault diagnosis capabilities, this paper introduces the multi-head self-attention mechanism. By simultaneously focusing on different parts of the input, capturing complex dependencies and global features, the model's adaptability and diagnostic accuracy under different working conditions are improved. In summary, the main contributions of this paper are as follows:  
1. Proposing a method that combines one-dimensional and two-dimensional transformations of acoustic signals for feature fusion using ResNet. 2. Introducing the multi-head self-attention mechanism to enhance the model's feature extraction capability and diagnostic performance. Demonstrating through experiments the superiority of this method in bearing fault diagnosis, showcasing its high adaptability and reliability under different working conditions. Through this study, a novel and effective method is provided for rolling bearing fault diagnosis, with significant theoretical significance and application value. The rest of this paper is organized as follows. Section 2 details the proposed theoretical methods. Section 3 presents the experimental validation of the proposed method. Finally, Section 4 concludes the paper.
# Carbon Nanotubes-Based Hydrogels for Bacterial Eradiation and Wound-Healing Applications
## 2 Conductive Properties of CNTs  
CNTs are an allotropic form of carbon, as mentioned by [PERSON] in 1991 [38], which have similar properties as graphene. Structurally, CNTs are cylindrical structures composed by the rolling of graphene sheets with sp\({}^{2}\) hybridization. Arc discharge, laser ablation, and chemical vapor deposition (CVD) are commonly utilized to prepare CNTs [39]. In arc discharge and laser ablation methods, the carbon sourced was treated at 3000-4000 \({}^{\circ}\)C to generate cylindrical CNTs, whereas the CVD technique involves the pyrolysis of carbon source at a temperature range of 600-1100 \({}^{\circ}\)C. The physicochemical properties of the obtained CNTs are widely influenced by synthetic methods [40]. CNTs exhibit remarkable thermal properties due to their structural form and technique of synthesis. The conductivity range of CNTs can vary from 6000 to 0.1 W/mK depending upon the single-walled structure and multi-walled structure, respectively [41; 42]. The thermal conductivity is due to the collective vibration of atoms, including phonon and electron transfer [43; 44].  
Figure 1: A scheme showing the types of CNT, properties of CNT hydrogel patches, and their application in cell proliferation [34], cell migration [35], antibacterial [36], and wound healing [37].  
The length of CNTs also affects the conductivity [44; 45]. Therefore, the optimization of synthetic parameters is required to obtain a certain level of thermal conductivity [46]. [PERSON] et al., studied molecular dynamics simulation to determine the thermal conductivity (k = 6600 W/mK) of CNTs based on Tersoff-Brenner potential, which is similar to a hypothetical isolated graphene monolayer [47]. In comparison, [PERSON] et al., studied the relationship between the physical parameters of CNTs and their thermal conductivity. They examined that the thermal conductivity of single-walled carbon nanotubes (SWCNTs) changes with the temperature. A decrease in the thermal conductivity of armchair (10,10) configured SWCNTs was observed above 400 K, similar to monolayered graphene. The CNTs with similar diameters but different chirality show maximum conductivity at 300 K, and the armchair CNTs have a comparatively sharper peak than zigzag CNTs [48]. Table 2 shows various properties of single-walled carbon nanotubes (SWCNT) and multi-walled carbon nanotubes (MWCNT).
# Towards a Cyber-Physical Range for the Integrated Navigation System (INS) System (INS)
## 3 The Composition of the INS
### Communication Protocols and Interfaces  
#### 3.2.1 Non-Device-Specific  
The IEC 61162 _\"Maritime navigation and radio communication equipment and systems--Digital interfaces\"_ standard defines digital interfaces for navigation, radio communication, and system integration in marine vehicles. The standard consists of five sections, as follows [84]:  
* IEC 61162-1: Single talker and multiple listeners;
* IEC 61162-2: Single talker and multiple listeners, high speed transmission;
* IEC 61162-3: Multiple talkers and multiple listeners--Serial data instrument network;
* IEC 61162-450: Multiple talkers and multiple listeners--Ethernet interconnection;
* IEC 61162-460: Multiple talkers and multiple listeners--Ethernet interconnection--Safety and security.  
The IEC 61162-1 is alternatively called NMEA 0183 [84]. The IEC 61162-3 is also called NMEA 2000 [18; 85]. NMEA 2000 is based on CAN [17; 18]. Although IEC 61162 is referred in IMO documents (e.g., MSC.112(73) [60]) as a footnote, many bridge devices are compliant with IEC standards [3].  
As shown in Figure 2, an IEC 61162-1 type of message consists of several parts, namely start of sentence delimiter, talker identifier (Talker ID), and checksum. The message initiates with the $ symbol, and the talker identifier follows it. The field sentence constitutes the last part of the IEC 61162-1 sentence. The IEC 61162-1 has 124 types of field sentence formats for different data, for example \"RPM--Revolutions\", \"RSA--Rudder Sensor Angle\", \"HCR--Heading Correction Report\". Each field sentence has its own format, and the message can be understood using the guidelines in the IEC 61162-1. Therefore, 65 types of talker identification are available in the IEC 61162-1. The talker identifier states the data source, namely GPS, GLONASS, and eLORAN.  
The Inter-VTS Data Exchange Format (IVEF) is a standard framework for data exchange between maritime control centers (i.e., VTS) [86; 87]. The IVEF was developed by the IALA with the contribution of Saab (HITT Traffic), Kongsberg Norcontrol IT, ATLAS Maritime Security, Transas, Japan Radio Co., Oki Consulting Solutions, Rijkswaterstaat, Sofrelog, Lockhead Martin, NaviElektro, Selex Sitemi Integrati [88].  
No official document containing a list of interfaces exists; instead, manufacturer brochures for bridge equipment were used to determine interfaces in use. Such interfaces are DVI, RJ-45, RS-422, USB, RS-232, RS-485, and M12. Moreover, PL-259 or SO-239 for VHF antennas, TNC or SMA for GPS antenna are used.
# Stability and Failure of the Edge-Closed Honeycomb Sandwich Panels with Face/Core Debonding
## 1 Introduction
The propagation behavior of interface debonding and core crack was predicted by [PERSON] and [PERSON] [19] by a model with cohesive elements. [PERSON] and [PERSON] [20] developed a 3D model based on the finite element method to predict the residual strength of debonded sandwich panels. Based on finite element analysis and linear elastic fracture mechanics, [PERSON] et al. [21] studied the initial buckling load and compressive strength of a delaminated sandwich panel with a circular core. [PERSON] et al. [22] used a new 3D finite element modeling method to study the effects of face/core debonding size, shape, aspect ratio, fiber direction, and core stiffness on the buckling behavior of honeycomb panels under different boundary conditions. The objects of the above studies are mostly for sandwich structures of the element level and constant thickness. However, the edges of the honeycomb sandwich structure are usually beveled and closed [23], which is easy to connect and transfer load. [PERSON] et al. [24] developed a new technology, which was well known for its asymmetric sandwich structure, and it was used to design lightweight structures. [PERSON] [2] experimentally studied the effect of debonding defects in the beveled area on the failure process when edges-closed honeycomb sandwich structure was subject to compressive loads. The results showed that the debonding defect in the beveled zone had a small effect on the compressive strength of the structure, but had a large effect on the strain of the inner panel. [PERSON] et al. [25] studied the influence of plate/core debonding defects on the buckling load and instability mode of edge-closed honeycomb panels by finite element method. [PERSON] et al. [26] studied the stability and failure behavior of asymmetric sandwich structures under asymmetric compressive load through experiments and finite element analysis. However, there was less research on the edge-closed honeycomb sandwich structure with debonding defects in the public literature. In this paper, experimental and simulation studies on the mechanical properties under axial compression load of the edge-closed honeycomb sandwich structure were developed. Two sizes of face/core debonding area were designed according to variation law of buckling load calculated by finite element analysis, and corresponding compression tests were designed. Then, the buckling load, ultimate load and failure mode of edge-closed honeycomb structures with different debonding sizes under axial compressive load were obtained. The results of experiments were in good agreement with the results of the progressive failure model of face/core debonding composite sandwich structures established by combining cohesive zone model (CZM) technique and progressive failure analysis. The present study had guiding significance for the assessment on damage tolerance of edge-closed honeycomb sandwich panels with face/core debonding.
# A Stronger Adaptive Local Dimming Method with Details Preservation
###### Abstract  
Local dimming technology focuses on improving the contrast ratio of the displayed images for a great visual perception. It consists of backlight extraction and pixel compensation. Considering a single existing backlight extraction algorithm can hardly adapt to images with diverse characteristics and rich details, we propose a stronger adaptive local dimming method with details preservation in this paper. This method, combining the advantages of some existing methods and introducing the combination of the subjective evaluation and the objective evaluation, obtains a stronger adaptation compared with others. Besides, to offset the luminance reduction caused in the backlight extraction process, we improve the bi-histogram equalization algorithm and propose a new pixel compensation method. To preserve image details, the Retinex theory is adopted to separate details. Experimental results demonstrate the effect of the proposed method on contrast ratio improvement and details preservation.  
Keywords:local dimming; retinex theory; bi-histogram equalization; contrast ratio; details preservation +
Footnote †: journal: Applied Sciences
# Verifiable (2, \(n\)) Image Secret Sharing Scheme Using Sudoku Matrix
## 3 Research Methods
### The Procedure of Secret Image Reconstruction and Authentication  
During secret image reconstruction and authentication extraction, we can retrieve the \(y_{i,j}\) value according to the stego pixels \(B_{j}^{1\prime}\) and \(B_{j}^{2\prime}\). Equation (3) can be reconstructed when participant \(id\) as \(x_{i}\) is inputted as the participant ID. For example, in the previous example, \(y_{i,1}\) can be obtained by mapping the pixels \(B_{1}^{1\prime}\) and \(B_{1}^{2\prime}\) to indicate the digit 6 using a Sudoku matrix. Thus, Equation (3) can be reconstructed as \(6=\beta_{1}^{2}+\beta_{1}^{3}\mod 9\)  
Figure 5: Data embedding example with hidden number 6 changing \(\alpha_{1}\) and \(\alpha_{2}\) to 101 and 121.  
Any two participants can resolve the parameters \(\beta_{1}^{2}\) and \(\beta_{1}^{3}\). Using the same process, the parameters \(\beta_{2}^{2}\) and \(\beta_{2}^{3}\) can be extracted by the stego pixels \(B_{2}^{1\prime}\) and \(B_{2}^{2\prime}\).  
The values of \(z_{1}\) and \(z_{2}\) in Equations (4) and (5) can be reconstructed by mapping the stego pixel pairs (\(B_{1}^{3}\), \(B_{1}^{4\prime}\)) and (\(B_{2}^{3\prime}\), \(B_{2}^{4\prime}\)). For the previous example, as shown in Figure 6, when inputting the participant \(id\)\(x_{i}=1\), two equations can be reconstructed as \(1=\beta_{1}^{1\prime}+f_{2}\) mod 9 and \(8=f_{3}+\beta_{2}^{1\prime}\) mod 9. With any two participants, the parameters \(\beta_{1}^{1\prime}\), \(f_{2}\), \(f_{3}\), and \(\beta_{2}^{1\prime}\) can be extracted. The values \(f_{1}\) and \(f_{4}\) can be computed with Equations (8) and (9), respectively.  
\[f_{1},\beta_{1}^{1}=\begin{cases}0,\beta_{1}^{1\prime},&\text{if }\beta_{1}^{1 \prime}<4\\ 1,\beta_{1}^{1\prime}-4,&\text{otherwise}.\end{cases} \tag{8}\]  
\[f_{4},\beta_{2}^{1}=\begin{cases}0,\beta_{2}^{1\prime},&\text{if }\beta_{2}^{1 \prime}<4\\ 1,\beta_{2}^{1\prime}-4,&\text{otherwise}.\end{cases} \tag{9}\]  
After this, the secret pixels \(p_{1}\) and \(p_{2}\) can be reconstructed with Equation (10). Moreover, the average pixel, denoted by \(avg\), can be obtained via Equation (11). The reconstructed pixels \(p_{1}\) and \(p_{2}\) can be computed as an average value, denoted by \(avg^{\prime}\). The pixel is judged as authentic if the value \(avg^{\prime}\) is equal to \(avg\); otherwise, it is labeled inauthentic.  
\[p_{j}=\beta_{j}^{1}\times\theta^{2}+\beta_{j}^{2}\times 9+\beta_{j}^{3}. \tag{10}\]  
\[avg=f_{1}\times(2\times\theta^{2})+f_{2}\times(2\times\theta)+f_{3}\times 2+f_{4}. \tag{11}\]  
Figure 6: Example of secret pixel reconstruction and authentication code extraction, where the same shape is used for the same parameters in the analytical equation
## 5 Conclusions and Future Work
Finally, as future work, it could also be interesting to extend the range of experiments performed and analyze the potential interest of other ML methods; for example, we could consider applying different classifiers applied over different categories of data proposed in the paper and combine them into an ensemble. The following materials are available online at [[http://www.mdpi.com/2076-3417/10/17/5942/s1](http://www.mdpi.com/2076-3417/10/17/5942/s1)]([http://www.mdpi.com/2076-3417/10/17/5942/s1](http://www.mdpi.com/2076-3417/10/17/5942/s1)), File S1: Initial database. File S2: Coded database. File S3: Filtered database. File S4: Report for physician. Conceptualization, J.d.I.T., J.M., S.I., and J.J.M. ; data curation, J.d.I.T., J.M., and J.J.M. ; formal analysis, J.d.I.T., J.M., S.I., and J.J.M. ; funding acquisition, S.I. and J.J.M. ; investigation, J.d.I.T. ; methodology, J.d.I.T., J.M., and J.J.M. ; project administration, J.J.M. ; resources, S.I. and J.J.M. ; software, J.d.I.T. and J.J.M. ; supervision, S.I. and J.J.M. ; validation, J.d.I.T. ; visualization, J.d.I.T. ; writing--original draft preparation, J.d.I.T., J.M., and J.J.M. ; writing--review and editing, J.d.I.T., J.M., S.I., and J.J.M. All authors have read and agreed to the published version of the manuscript. This project was co-funded by the Government of Aragon, the European Regional Development Fund and the University of Zaragoza. We thank the support of the project TIN2016-78011-C4-3-R (AEI/FEDER, UE) and the Government of Aragon (Group Reference T64_20R, COSMOS research group). We thank Mapfre insurance company (Zaragoza, Spain) for allowing us to use their facilities. We also thank the I3A--University Institute of Research of Engineering of Aragon, University of Zaragoza, Zaragoza, Spain--for the materials and support they provided. The authors declare no conflict of interest. The following abbreviations are used in this manuscript:
## 2 Materials and Methods  
### Experimental Setup  
This study examines the operation of the OD employing simultaneous nitrification and denitrification technology. The laboratory setup and its operational principles were detailed in previous works [36]. The laboratory installation consisted of a model OD with vertical flow constructed from polycarbonate tubes with a diameter of 100 mm. It comprised two modules with volumes of 20 and 17 L, respectively. The reactor design ensured ideal mixing across the entire width of the corridor, free from any gravitational influences. The substrate feed rate varied from 4.2 to 7.5 L per hour. The reactor was equipped with a single sedimentation tank with a maximum active volume of 8 L. Synthetic wastewater was introduced into the OD using two solenoid dosing pumps operating in a batch dosing mode (50%/50%). A schematic representation of the setup is shown in Figure 1.  
The duration of the experimental phase was 24 months. The data obtained during the experiment are described in Section 2.4. The primary regulated characteristics of the setup included the concentration of dissolved oxygen across different zones (DO, mg/L), hydraulic retention time (HRT, hours), and mixed liquor-suspended solids (MLSS, mg/L). The sludge retention time (SRT) was maintained at 20 days. The MLSS concentration was adjusted by regulating the return-activated sludge flow, which allowed for a constant biochemical oxygen demand (BOD\({}_{5}\)) loading of 0.2 g/g/d, as required by the experimental conditions. In accordance with the BOD\({}_{5}\) concentration in the incoming wastewater, the dissolved oxygen levels in the individual bioreactor zones were also adjusted. In the first zone (A), the oxygen concentration varied from 0.1 mg/L to 0.5 mg/L, while in the second zone (B), it ranged from 0.35 mg/L to 0.8 mg/L. The HRT varied between 6.5 h and 12 h. The flow rate in the oxidation ditch was maintained at 0.2 m/s. A detailed description of the setup can be found in a previous study [36]. The primary focus of this research is the analysis of time series data reflecting the changing concentration of biochemical oxygen demand (BOD\({}_{5}\), mgO\({}_{2}\)/L).
## 3 Results and Discussion
### Bioaccessible Concentration  
Figure 3 reports the results of the UBM and SBET methods for the four samples collected at the firing range in terms of bioaccessible concentrations. Namely, for each sample, the concentrations measured in the gastric and gastrointestinal phases of the UBM (named UBM-G and UBM-GI, respectively) were compared with the values obtained by the SBET. For sample BGS102, the values of the bioaccessible concentration of As and Pb reported in the certificate of analysis provided by the supplier are also shown for comparison.  
Regarding the UBM results, it is possible to observe that for all the tested samples, the bioaccessible concentration measured for the different inorganics in the gastric phase was higher than that obtained for the gastro-intestinal phase. This result is in agreement with what has already been observed in previously published papers (e.g., [2; 15; 46]) that attributed this behavior to the strong influence of the pH of the solution. The pH of the gastric phase in fact was significantly lower (pH = 1.2) compared to that of the gastrointestinal phase (pH = 6.3), leading to a higher mobilization of the inorganics from the soil to the solution. As also stated by [PERSON] et al. [16], the change in pH from low to neutral values  
Figure 3: Comparison of the bioaccessible concentrations obtained applying UBM (UBM-G: gastric phase; UBM-GI: gastro-intestinal phase) and SBET to samples **A1**, **A2**, **S1**, and **S2**. The striped bars represent values below the limit of quantification.  
Figure 2: Bioaccessible concentrations obtained applying the Unified Barge Method (UBM) (UBM-G: gastric phase; UBM-GI: gastro-intestinal phase) and Simple Bioaccessibility Extraction Test (SBET) to BGS102. The striped bars represent values below the limit of quantification. A 10-fold dilution of the extract for the SBET was applied.  
passing from gastric to gastrointestinal conditions is likely to determine a precipitation of inorganics and hence a lower bioaccessibility.  
Comparing the bioaccessible concentrations obtained for the two methods, one can observe that, except for A2, which was probably affected by heterogeneity, the SBET proved to be more conservative, with values slightly higher than those of the UBM. Furthermore Figure 3 shows that for all the analyzed inorganics, the bioaccessible concentrations determined by the SBET were quite close to the values obtained for the gastric phase of the UBM (i.e., UBM-G). These results could have been expected considering that, although the two methods are characterized by very different procedures and reagents, the pH of the solution in the SBET and in the gastric phase of UBM were similar (1.2 compared to 1.5). This observation underlines once more that pH is a key parameter to consider for assessing bioaccessibility of inorganics.