esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Numerical Results
### Probability of Blocking an Authorized Node
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Scenario** & **Full** & **No AoA** & **No Delay** & **“Only Energy”** & **AoA \& Delay** \\ \hline \hline \multicolumn{5}{c}{CART} \\ \hline A1 & 95.43\% & 90.64\% & 94.67\% & 55.88\% & 90.70\% \\ A2 & 95.95\% & 89.92\% & 94.87\% & 55.94\% & 90.80\% \\ A3 & 96.53\% & 83.78\% & 81.08\% & 52.1  
The \(P_{ban}\) depends on the ML classification algorithm; hence, we compared the results of CART and random forest with those of other two basic ML classification methods, SVM and k-NN, to show the effectiveness of the selected ones. In Table 4, the classification accuracy of the four methods is reported for scenario A1. We considered a linear kernel for the SVN and \(k=20\) for the k-NN (different values of k were tested). The results show that in this scenario, accuracy is similar using different classification algorithms, thus supporting the effectiveness of the selected ones. Moreover, these present low complexity and less degrees of freedom, which can affect their performance. Indeed, k-NN is usually a low-complexity approach, but its performance requires a suitable selection of \(k\) that should be differently optimized for different scenarios; moreover, the computation load increases with \(k\). SVM instead requires a large amount of time to process; hence, it is suitable only if the data size is small and provides poor performance with overlapped classes (it can happen with proximity nodes). Finally, performance strongly depends on the hyperparameter settings.
## 1 Introduction
### Current Signature-Based Fault Diagnosis
This comprehensive evaluation underscores that the AHC-based approach not only improves classification performance but also mitigates the overfitting risk associated with multicollinearity, which is a gap in the current literature. To the best of our knowledge, this study represents the first application of an AHC-based feature selection strategy tailored for fault diagnosis in electrical machines. By explicitly leveraging harmonic-based features and addressing multicollinearity through Spearman correlation and hierarchical clustering, this approach offers a distinct advantage over previous clustering-based feature selection methods. In doing so, it bridges a critical gap in fault diagnosis methodologies, ensuring both high accuracy and strong generalization for industrial applications. The structure of this work is organized into seven sections, followed by references. The introduction establishes the objectives and significance of this study. Next, Feature Engineering outlines the process of extracting voltage and current phasor-based features, followed by an in-depth discussion on feature selection using the AHC algorithm. Section four examines the machine learning algorithms employed, while section five details the research methodology. The findings and their implications are presented in section six, leading to the final section, which synthesizes key conclusions and proposes directions for future research.
# Accelerate Incremental TSP Algorithms on Time Evolving Graphs with Partitioning Methods
## 3 Algorithms  
### Problem Definition  
In our problem definition, as explained in our previous works [14; 15], \(G\) is a complete, undirected graph. In a TSP problem, the tour is computed on a graph \(G(V,E)\), where \(V\) is the set of vertices and \(E\) is the set of edges. The goal is to compute a tour \(T\) where each vertex in the graph is visited exactly once such that the total traveling cost is minimum. The total traveling cost of a tour \(T\) is the sum of the weights of all the edges in tour \(T\). Now, the problem definition for solving TSP on TEG is different. For every update event, we have to find the minimum TSP tour \(T\) in each time interval. The TEG instance at time \(t\) is denoted by \(G_{t}=\{V,E\}\). The cost of an edge \((u,v)\) is defined as \(C(u,v)\), where \(u\) and \(v\) are two vertices. We only consider one type of update event i.e., change in edge weight, and we have assumed there can be only one update event for each time interval. Therefore, the update event is denoted by \(\Delta G_{t}(u,v,C(u,v))\), which means the weight of the edge \((u,v)\) is changed to \(C(u,v)\) at time interval \(t\).  
To explain the above problem definition, we will use same Figure 1 as used in our previous works [14; 15]. For example, the first row of images of Figure 1 illustrates an update event \(\Delta G_{t}=(1,3,50)\) and \(\Delta G_{t+1}=(2,3,30)\) at time interval \(t\) and \(t+1\), respectively. This means that the weight of vertices 1 and 3 is updated to 50 at time interval \(t\), and similarly, the weight between vertices 2 and 3 is changed to 30 at time \(t+1\). The second row of images of Figure 1 shows the respective TSP tours of each graph. Our objective is to compute the minimum TSP tours {0, 3, 1, 2, 0}, {0, 3, 2, 1, 0} and {0, 3, 2, 1, 0} for every time interval. To achieve this objective, we have proposed an incremental algorithm, which is discussed in the next subsection.
## 3 Theoretical Framework
### Monolithic Architecture  
In general, the monolithic architecture uses a single development technology, limiting the availability of a suitable tool for each task that the system needs to execute. According to [PERSON] [27], in a single logical executable, any change completed in a section of this kind of system involves the construction and deployment of a new version of the entire system. Most involved aspects or layers of presentation, processing, and storage are a single component of software required to run on a server (See Figure 2).  
In concordance with the State of the Art section of our study, the monolithic architecture offers some advantages and disadvantages that give rise to confidence or technological drawbacks. It is necessary to know the risks that can lead to short or long-term problems [28]. Among the most significant advantages, there are stable systems, the full manage system, used by large companies in the world such as IBM, Sun Microsystems, and BMC. The professional services of these companies have a high level of knowledge about their products. Among some disadvantages: they are rigid systems and are difficult to adapt to new needs. The increase in its processing capacity goes through changing the current server for a larger one. Its technology is proprietary, which creates a significant dependency on the client towards the supplier company. Its acquisition, renewal, and support costs are high. We propose some examples of restriction of these kind systems in Section 3.5.  
Every computer system is required to evolve and to follow trends such as solid-state disks surpassed punched cards. The level of complexity of modern systems requires improvements in both software production and performance. Thus, this means that it has found inevitable defects in the monolithic architecture [29]. Which, over time, will contrariwise to itself, giving rise to modern architectures such as microservices. There are cases in which applications are more efficient using this type of construction, e.g., firmware, key Logger, and viruses.
# Ionospheric Narrowband and Wideband HF Soundings for Communications Purposes: A Review
## 3 State of the Art of Sky Wave Sounding
### Damson
#### 3.3.2 System Deployment  
The project was sounding from mid-1990s to the early 2000s, which is more than half a solar cycle, although it was described around 1994. This system was deployed with two transmitters and two receivers in northern Scandinavia, which are described in Figure 4, with 10 frequencies to characterise all four paths in the auroral, sub-auroral and polar regions. It was sounding every 10 min on each of 10 frequencies from 2.8 MHz to 21.9 MHz for multiple years (24 h/day) in these 4 places, although other sites have also been used for some concrete studies.  
The three longest radio links, Isford-Tuentangen, Isford-Kiruna, Harstad-Tuentangen, are approximately north-to-south oriented, and the prediction programs depicted that these links exhibit multi-hop propagation and multi-mode propagation for some frequencies and times-of-day.  
* The Harstad-Tuentangen link is placed on a sub-auroral region, except for highly geomagnetically active periods.  
Figure 4: Deployment of the main sites used in the DAMSON project to sound the ionosphere. We can observe auroral, sub-auroral and polar regions.  
* The Isford-Tuentangen link exhibits a multi-hop paths that may reflect from ionospheric regions inside the polar cap, in the auroral zone or below the auroral zone.
* The Isford-Kiruna path, 1150 km, falls almost completely in the auroral region, ensuring that reflection zones are in a highly disturbed region of the ionosphere.  
The shortest radio link (180 km), Harstad-Kiruna, is a west-to-east oriented near vertical incidence skywave (NVIS) path. The NVIS maximum range is approximately 200 km, for this reason these links can exhibit ground wave propagation, producing self-interference at the receiver. The DAMSON project has analyzed two NVIS radio links, the aforementioned Harstad-Kiruna and Harstad-Abisko (68.34 \({}^{\circ}\)N 18.83 \({}^{\circ}\)E), which is a 120 km link.  
As it was mentioned previously, other radio links were also deployed for particular works. For instance, DAMSON was setup in Thailand in 1997 to measure an equatorial HF channel of a 600 km path. The transmitter was located at 7.2 \({}^{\circ}\)N, 100.6 \({}^{\circ}\)E and the receiver was located at 12.7 \({}^{\circ}\)N, 101.0 \({}^{\circ}\)E creating a north-south oriented path.
## 2 Dataset, Models and Method
### Dataset
#### 2.1.5 Satellite Cloud and Rainfall Products  
The global full-resolution (\(\sim\)0.04\({}^{\circ}\)) infrared (IR) data, merged from several geostationary satellites (\(\sim\)11 micron channels), and available from NASA at 30-min intervals, were used as cloud observations. Lower brightness temperatures in the IR images indicate sufficiently thick clouds whose cloud tops radiate at the atmospheric temperature at higher altitudes.  
Rainfall data derived from the Tropical Rainfall Measuring Mission (TRMM) were used for model validation. These gridded estimates (3B42) are available with 3-hourly temporal resolution and \(0.25^{\circ}\times 0.25^{\circ}\) spatial resolution in a global belt extending across latitudes from 50\({}^{\circ}\)S-50\({}^{\circ}\)N.
# Multilevel Coding for the Full-Duplex Decode-Compress-Forward Relay Channel
## 3 Decode-Compress-Forward  
In this section, we re-derive Theorem 7 [2] for the discrete memoryless relay channel under backward decoding and obtain the DCF achievable rate for the AWGN relay channel as well as the constellation constrained AWGN relay channel.
## 2 Materials and Methods
### Wettability and Free Surface Energy Determination  
Wettability on polysaccharide nanocomposites has always been a subject of considerable interest. Wettability experiments typically use the contact angle to characterize aqueous drops' wetting capacity on a solid surface and judge their suitability for different applications. Wettability affects ink receptivity, coating, absorbency, adhesion, and frictional properties. However, due in part to the rough, porous, and water-swellable nature of bio-polymer materials, poor fits between various theories and contact angle data have been observed. Therefore, the more sophisticated measurement of the surface free energy of solids is necessary for better material characterization.  
In our research, we used the Drop Shape Analyzer Kruss DSA100M optical contact angle measuring instrument (Hamburg, Germany, Gmbh). The detailed methodology of the contact angle experiments, as well as the surface free energy analysis, were presented in our previous paper [20]. We used the Owens-Wendt method [39], which is generally accepted as the best for polymer evaluation. An exact and detailed introduction to the Owens-Wendt method was presented by [PERSON] and co-workers [40]. All measurements were performed in the special environmental cell at constant temperature conditions (22 \(\pm\) 0.3 \({}^{\circ}\)C) and humidity. For each foil sample, more than three successive tests were carried out.
###### Abstract  
Development of synthetic aperture radar (SAR) technology and the dedicated suite of processing tools have aided the evolution of remote sensing techniques for various Earth Observation (EO) applications. Interferometric SAR (InSAR) is a relatively new geodetic technique which provides high-speed and reliable geographic, geologic, and hazards information allowing the prognosis of future environmental and urban planning. In this study, we explored the applicability of two differential interferometry techniques, conventional and advanced differential InSAR (A-DInSAR), for topographic mapping and long-term geotechnical monitoring by exploiting satellite data, particularly Sentinel-1 SAR data, which is publicly shared. We specifically used the open-source tools of SeNtinel Application Platform (SNAP) and Stanford Method for Persistent Scatterers (StaMPS) for interferometric data processing to implement A-DInSAR. This study presents various applications, which include generation of a digital elevation model (DEM), mapping of seismically induced displacement and associated damages, and detection and long-term monitoring of tunneling-induced ground deformation and rainfall-induced landslide. Geometric and temporal decorrelations posed challenges and limitations in the successful implementation of Sentinel-1 SAR interferometry specifically in vegetated areas. The presented results proved the validity and reliability of the exploited SAR data and InSAR techniques for addressing geotechnical engineering related problems.  
emote sensing; geotechnical engineering; Sentinel-1 SAR data; SNAP-StaMPS; InSAR; A-DInSAR; ground deformation; South Korea
# Upscaling Customer Access Network Using Spectrum Conversion-Slicing-Duplication Technique
## 1 Introduction
### EDFA-Based Technique  
Without the use of a repeater, optical signals can be transmitted across great distances using erbium-doped fiber amplifiers (EDFAs). This enables the improvement of DWDM systems by incorporating extra sources at various wavelengths and DWDM multiplexing them into a single cable. Applications for WDM and fiber-to-the-home (FTTH) create  
Figure 2: Technique using AWG.  
conflict and also present opportunities for the optical community. WDM operates at 1-40 GHz with channel separations as small as 0.8-0.4 nm in high-capacity situations. Advanced components are needed for this technology, such as a very stable wavelength source, precise optical filtering, cross-channel light management, and so on. Up until now, its network-access apps have been constrained. WDM is a very promising method for making use of the optical fiber's available bandwidth. However, due to the high cost of traditional WDM optical components, its usage for inclusion is restricted. The design of multiplexers and demultiplexers is more straightforward, and the tolerances are larger, in order to lower the price of optical transceivers and slow down the design criteria for WDM systems [15].
## 5 Discussion
### Theoretical Implications  
This study contributes to the literature examining the link between information-technology use and subjective well-being in three ways. First, we empirically tested the relationship between the influence of receiving online support and that of providing online support on subjective well-being. Although the previous literature argues that receiving support from others in a social unit increases an individual's perception of well-being (e.g., [1]), few studies on social media have simultaneously investigated the effects of receiving and providing online support on subjective well-being. Therefore, this study contributes to the existing literature by providing empirical evidence that receiving online support and providing online support are strong predictors of subjective well-being.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Paths**} & \multicolumn{2}{c}{**Standardized Path Coefficient**} & \multirow{2}{*}{**Statistical Comparison**} \\ \cline{2-2} \cline{4-4}  & **Low-Experience** & & **High-Experience** \\  & **Group (N=113)** & & **Group (N = 154)** & \\ \hline Receiving Online & & & \\ Support\(\rightarrow\)Subjective Well-Being & 0.12 & 0.47 * & \(-\)28.79 * \\ \hline Providing Online & & & \\ Support\(\rightarrow\)Subjective Well-Being & 0.63 * & 0.13 & 40.39 * \\ \hline \hline \end{tabular}
\end{table}
Table 4: Statistical comparison of paths for users with low- and high-use experience. * \(p<0.1\).  
Second, while past studies have used the perspective of experience to examine the change of personal beliefs over time (e.g., [48; 49]), few studies have been conducted to test whether the influences of online social-support activities (receiving and providing support) on subjective well-being vary as experience increases over time. This study contributes to the existing studies on well-being and social media by proving that receiving online support plays an important role in facilitating the perception of well-being for users with high levels of experience, while providing online support increases the perception of well-being for users with low levels of experience.  
Finally, although online social support has been considered an important factor that determines individual behavior [1]. Little is known about the motivating factors for users' social-support activities on social media. This study empirically tested the influence of social capital on online support activities and found that social capital fosters users' online social-support activities. The results contribute to the existing literature on social media by revealing that social capital motivates members of a network on social media to provide and receive help from other members.
## 5 Conclusions and Future Work  
Audio signals can be processed either in the time domain, treating the raw signal, or in the frequency domain. In the latter case, visual representations of the audio (images) are used. This research proposes a model for cleaning background noise in audio signals (human speech) using a VAE composed of 2D convolutional filters applied to a two-dimensional representation of the audio signal, namely power log spectrograms. In the research, we propose four different scenarios that simulate environmental noise produced by storms, wind, traffic jams, and aircrafts. The whole workflow of the research comprises different stages. First, we created an ad hoc dataset by mixing speech audios with background noises, representing the four use cases. Then, we used this dataset to train a VAE with pairs of audios with background noise and only the speech audio using spectrograms. To measure if we had trained the model accurately, we used objective and subjective measures. Objective measures allowed us to measure mathematically, which is the scenario where the background noise is more difficult to suppress and whether the proposed model overcomes other models proposed before. The subjective evaluation allowed us to confirm the previous results based on the auditive perception of some people. Subjective evaluations are normally not performed in the works compiled in the state-of-the-art as there is a need to transform the spectrograms into audios so they can be listened to by the surveyed people. This transformation is not easy to apply as it depends on the phase that corresponds to the original speech's clean audio. In our case, we have applied the IFTF and although it does not achieve perfect results, it does obtain perfectly evaluable audios by using the phases of the audios that are the inputs for the model.  
The mathematical metrics produced by our model confirm that it performs better than the selected baselines in all cases. If we look at the results between the use cases, we can see that storms and rains are easier to eliminate. Looking at the standard deviation, we can see that wind cases have the worse results in a few examples. In this case, it should be highlighted that the scenario of background wind is the one with the smallest differences between the noisy audio and the cleaned one. This is confirmed in the objective evaluation where surveyed people evaluate this scenario as the one with the best performance.  
As future works, the main need is to obtain a method that could calculate, in a more precise way, the phase of the cleaned audio. Also, there is a need to obtain a more balanced dataset where the differences between the audio with background noise and the audio after  
Figure 3: Human evaluation of noise suppression by listening to a set of audios.  
using the model are smaller between scenarios. From a practical perspective, the model could be integrated into applications, so the model works with streaming audio.
## 1 Introduction
For example, [PERSON] and [PERSON] examined geometric influences, such as pillar shape, pillar orientation, and pillar slope, on the dynamic and electromechanical properties in the 1-3 piezoelectric composite design, through finite element analysis (FEA) [32; 33]. [PERSON] and [PERSON] demonstrated the numerical analysis of an air-coupled 1-3 composite transducer in respect of the influence of air propagation [34]. [PERSON] and [PERSON] proposed a homogenizing method of 1-3 piezo composites and verified the feasibility through the FEA [35]. [PERSON] et al. simulated mechanical stress in the interfacial area of a flexible 1-3 composite transducer [36]. Another [PERSON] et al. demonstrated the benefits of 1-3 composite transducer with the wide frequency bandwidth, capturing pulse-like signals in an enhanced accuracy [27]. However, in past research, there has been a lack of investigations on the extensive parametric study through structure-acoustic coupled numerical analysis and the corresponding influence on the actual acoustic pressure output in interstitial FUS transducer. Therefore, given the recent increase of attention to the interstitial FUS transducers, the systematic methodology to predict the performance of such miniaturized transducers under coupled physical conditions is very substantial and meaningful to reduce engineering cost before fabricating the actual device. The goal of this study is to design a miniaturized (<2 mm in the aperture size) FUS transducer with a 1-3 piezoelectric composite (Figure 1) and to predict the performance of the new design by using FEA. In this study, we hypothesized that the 1-3 piezoelectric material is beneficial for the efficient delivery of ultrasound waves along the thickness direction owing to the decoupling of the lateral vibration mode. The research scope of this study is to design a miniaturized, interstitial, 1-3 piezo composite FUS transducer and to validate the feasibility through computer simulation. This article is organized as follows. In the method section, we introduce the analytical and numerical models to predict the acoustic pressure output over the acoustic field. The design method for the confocal FUS transducer is also demonstrated. The result section will provide the influence of the extensive parametric variation on the transducer performance. The simulation results will suggest the optimal design of a single 1-3 composite element and will predict the performance of the confocal transducer. Finally, we will make the relevant discussions on the simulation results, followed by the conclusion of the research. The study provides a promising, novel design of the interstitial FUS transducer capable of delivering a high acoustic intensity.