esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Results and Discussion
### Characterization
Figure 4 presents the N\({}_{2}\) adsorption-desorption curves and pore size distribution for the as-grown SWCNTs and SWCNTs/Fe\({}_{\text{x}}\)O\({}_{\text{y}}\), and the specific surface area, pore volume, and average pore diameter of the two nanocomposites are given in Table 1. As demonstrated in Figure 4 and Table 1, it appears that the adsorption-desorption isotherm exhibits an H\({}_{3}\) hysteresis loop, and compared to the as-grown SWCNTs, the SWCNTs/Fe\({}_{\text{x}}\)O\({}_{\text{y}}\) has a larger specific surface area and pore volume and a larger pore diameter. The specific surface area of a material is determined by the synergistic contribution of micropores, mesopores, and macropores. Generally speaking, a larger capacity of micropores correlates with a higher specific surface area of the material, and when mesopores and macropores are present in significant quantities, the average pore size of the material tends to decrease. It is evident that thermal treatment effectively removes amorphous carbon, which is favorable for the formation of micropores. This not only increases the number of adsorption channels but also prolongs the adsorbate residence time within these channels due to the abundance of micropores. As a result, adsorbate molecules are more easily adsorbed onto the SWCNTs/Fe\({}_{\text{x}}\)O\({}_{\text{y}}\). Figure 3: XPS spectra of SWCNTs/Fe\({}_{\text{x}}\)O\({}_{\text{y}}\) and as-grown SWCNTs. Figure 2: (a) XRD images and (b) Raman spectra of as-grown SWCNTs and SWCNTs/Fe\({}_{\text{x}}\)O\({}_{\text{y}}\). Figure 5a is the hysteresis loop of the SWCNTs/Fe\({}_{\text{x}}\)O\({}_{\text{y}}\). The coercivity and remanence of the SWCNTs/Fe\({}_{\text{x}}\)O\({}_{\text{y}}\) are both zero, indicating the paramagnetic nature of this nanocomposite material. The saturation magnetization strength at room temperature is measured at 33.32 emu/g, suggesting that this material is capable of achieving solid-liquid separation. Figure 5b is a photo of a small experiment in which magnetic SWCNTs/Fe\({}_{\text{x}}\)O\({}_{\text{y}}\) can be rapidly collected in a BPA solution with a concentration of 0.25 mmol/L using magnets.
## 4 Discussion
### Comparison with the Other Low Cost Excitation Sources  
The most significant drawbacks of the low-cost sources that have been presented in the introduction are: lack of omnidirectionality (balloon, gunshot, handclap, wooden clapper, shotsell primer), lack of repeatability (handclap), uneven frequency response (balloon, gunshot, firecracker, handclap, wooden clapper) and lack of sound power (handclap, inverse horn design).  
The proposed method does not have any of the above drawbacks. With the correct implementation of the method presented in this paper, a common directional speaker can perform as an omnidirectional source. Also, excellent repeatability can be achieved since for every measurement the same sound field is generated. In addition, signal energy tends to be evenly distributed across a wide range of frequencies in the case of a directional loudspeaker of good quality. Hence, if a common directional speaker with a flat frequency response is utilized for the proposed method, then the emitted sound could presumably also approach a flat frequency response. Satisfactory sound power can also be achieved if a directional speaker with enough sound power is used. Research in improving omnidirectionality and the frequency response of the proposed method, is already underway.  
Concerning the measurement time of the specific method, it depends on the experience of performing the method and on the number of positions. There is not much time difference compared to measuring with a dodecahedron speaker, since impulse responses can be measured consecutively by changing the speaker position.  
Finally, the low-cost of the method can be further enhanced by commercially free software available for impulse response measurements [49]. Also for the generation of the impulse response from the sum of the impulse responses, beside the software that was used (Matlab), digital audio workstations can also be employed with minimum or no cost [50].
# End-to-End Online Video Stitching and Stabilization Method Based on Unsupervised Deep Learning
## 3 Experimental Results and Analysis
### Ablation Experiments
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \(\lambda_{0}\) &
\begin{tabular}{c} **Epochs to** \\ **Converge** \\ \end{tabular} & **PSNR** & **SSIM** & **Description** \\ \hline
1 & 34 & 29.68 & 0.889 &
\begin{tabular}{c} Slow convergence; slightly \\ lower alignment score. \\ \end{tabular} \\
2 & 28 & 30.01 & 0.891 &
\begin{tabular}{c} Slight improvement; \\ convergence still slow. \\ Best balance. \\ \end{tabular} \\
3 (default) & 22 & 30.41 & 0.893 &
\begin{tabular}{c} Best balance. \\ Faster convergence, \\ but lower scores. \\ Very fast convergence, but \\ scores drop significantly. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Ablation experiments on the selection of parameter \(\lambda_{0}\).
# Wear Behavior of Uncoated and Coated Tools in Milling Operations of AMPCO (Cu-Be) Alloy
## 3 Results and Discussion
### Coating Tools' Characterization  
To characterize the tools' coatings, samples were prepared according to the procedure described in the previous section. The samples were then subjected to SEM analysis. The coating structure was analyzed using SEM, as well as its chemical composition via carrying out EDS analyses. It was determined that the coating had a multilayered structure, composed of CrN and DLC layers, as can be observed in Figure 2a. The thickness of the layers was also determined, by performing different measurements in different places of the sample. An example of the measurements performed can be observed in Figure 2b.  
Figure 1: Positioning and lebelling used the y-the tools’ analyses: (**a**) Label used in the tools’ analyses; (**b**) label used for rake face of cutting knife 1.  
As can be observed in Figure 2a, the coating is composed of four layers, each of these was subjected to EDS analyses and their chemical compositions were determined. The spectra obtained from these can be observed in Figure 3.  
In Table 5, the average coating thickness for each layer (identified by zone, according to Figure 2a) and their respective compositions are presented.  
Figure 3: EDS spectra for each of the zones in Figure 2: (**a**) Z1; (**b**) Z2; (**c**) Z3; (**d**) Z4.  
Figure 2: Coating characterization: (**a**) identification of the different layers (Z1—CrN, Z2—DLC, Z3—CrN, Z4—DLC); (**b**) thickness measurement of the coating.  
The coating is composed of alternating layers of CrN and DLC (as previously mentioned), with the first deposited layer being composed of CrN. This multilayered structure improved the crack propagation resistance of the coating. Furthermore, the outer layer was a DLC coating, acting as a solid lubricant, enabling for lower friction generated during machining.
# An Improved Federated Learning-Assisted Data Aggregation Scheme for Smart Grids
## 6 Proposed Scheme
### Share Decryption and Share Combining  
In order to safeguard the confidentiality of the local data throughout the learning process, we employed a threshold homomorphic encryption technique to encrypt the model parameters of each user \(u\). Additionally, to mitigate the risk of information leakage pertaining to intermediate learning results and the final model, Gaussian noise is incorporated into the encryption process of the model parameters \(y_{u}\). Furthermore, to establish the authenticity of user identities, a Fiat-Shamir zero-knowledge proof [38] is constructed, enabling the server to authenticate the user's identity.  
During Round 2, each user utilizes their individual public key \(h_{u}^{PK}\) to encrypt the previously noise-added data \(y_{u}\), resulting in  
\[Z_{u}=\mathbf{Enc}_{pk}(y_{u}+noise(\epsilon,t^{\prime}))\]  
where \(\epsilon\) represents the privacy guarantee, and \(t^{\prime}\) refers to the number of non-colluding parties.  
Figure 3: Interaction between the edge node and the cloud server.  
Figure 2: Initialization process.  
Based on the Paillier cryptosystem, each user is required to compute the following expression:  
\[Z_{u}=g^{(y_{u}+noise(e,t^{\prime})}r^{n}\]  
where \(n=p\cdot q\), and \(r\in\mathbb{Z}_{n^{2}}^{*}\) denotes a randomly chosen number.  
In Round 3, \(\bar{t}=n-t^{\prime}+1\) users are selected by the server to perform decryption sharing on \(Z^{\prime}\), which is the service aggregate.  
Each user initially computes  
\[a_{n}^{\prime}=a^{\Delta f(u)}\ mod\ n^{2}\,\qquad f(x)=\sum_{u}^{k-1}x^{u}\]  
and transmits it to the server. Upon receiving these values, the server computes the aggregated encrypted value \(Z^{\prime}\) as \(Z^{\prime}=\mathbf{Enc}pk(y1+y_{2}+\cdots+y_{n})\gets Z_{1}\circ Z_{2} \circ\cdots\circ Z_{n}\). In other words, \(Z^{\prime}\) is equal to \(g^{Y}r^{n}\), where \(Y=\sum_{u\in\mathcal{U}_{\mathcal{U}_{\mathcal{U}}}}y_{u}\).  
Subsequently, each user computes \(Z_{u}^{\prime}=Z^{\prime\Delta f(u)}\) based on the received \(Z^{\prime}\) and forwards it to the server. Upon receiving these data, the server verifies the correctness as follows:  
\[\log_{Z^{\prime\pm}}(Z^{\prime\pm}_{u}) =\log_{Z^{\prime\pm}}(Z^{\prime\pm f(u)})\] \[=\log_{\mathbb{Z}_{u}}(a^{\Delta f(u)})\] \[=\log_{\mathbb{Z}_{u}}(a_{u}^{\prime})\]  
If the server possesses a sufficient number of shares and valid **proof**, it can merge them to obtain the final result by selecting a subset \(S\) of \(\bar{t}\) shares, combining them as follows:  
\[M=\prod_{u\in S}Z^{\prime\pm 2\Delta_{u}^{S}}\ mod\ n^{2}\]  
where \(\Delta_{0,u}^{S}=\Delta\prod_{u^{\prime}\in S\emptyset}\frac{-u}{u-u^{\prime} }\in\mathbb{Z}\).  
The value of \(M\) can be expressed as \(M=Z^{\prime 4\Delta^{2}}\mod\ n^{2}\). It should be noted that \(4\Delta^{2}=0\mod\lambda\). Therefore, the server can deduce that \(M=(1+n)^{4\Delta^{2}Y}\mod n^{2}\). Considering that \((1+n)^{x}\equiv 1+nx\mod n^{2}\), we have \(1+4n\Delta^{2}Y\). The server can calculate \(Y=\frac{M-1}{4n\Delta^{2}}\).
## 8 Applications of UWSN Technology
### Monitoring Water Quality  
Monitoring water quality entails examining the water characteristics of dams, rivers, lakes, seas, and subsurface water reservoirs. The deployment of permanent monitoring stations in hard-to-reach sites is made possible by using wireless dispersed sensors, which also allows for producing a more accurate map of the water status.
## 3 Results and Discussion
### Structural Response  
#### 3.2.1 Load-Defection Curves  
The load-deflection responses of B1-B6 and their replicas are presented in Figure 7, obtained from the four-point loading test (described in Section 2.2.3). For all beams, this figure demonstrated that repeatability of acceptable results has been accomplished, as close curves were obtained for the duplicated specimens. Figure 7 demonstrated that increasing the amount of tensile reinforcement in the UHPC beams could increase the load-bearing capacity and change the failure pattern from brittle to ductile. In this context, B6 (Figure 7) represents a typical reinforced concrete beam behavior. According to this finding, fibers are likely of marginal importance in accelerating the load-bearing of shear-deficient UHPC beams.  
Figure 8a displays a comparison of the representative load-deflection curves for the tested UHPC beams. As expected, for the beams with low reinforcement percentages (0-0.84% (B1-B3)), a sudden brittle flexural failure was observed. However, the use of the medium to high \(\rho\) (1.21-3.35% (B4-B6)) altered this failure behavior to semi-ductile to ductile ones. Figure 8a also shows the loading and energy absorption capacities (especially after yielding the bar reinforcement), as would be anticipated. Moreover, the ultimate midspan deflection of the UHPC beams with low reinforcement percentages (B1-B3) was almost constant (about 8 mm) and increased as their reinforcing cont  
Figure 6: Flexural load displacement response: (**a**) UHPC-C, (**b**) UHPC.  
it notably increased as it reached higher reinforcement levels (B4 to B6). This displacement response could be attributed to the brittle behavior of the first three beams (failure occurred right after the ultimate loading) compared to the improved deformability of the latter beams. Figure 8b shows the relation between the beam's ultimate load and reinforcement ratio. The trend of this relation was fairly linear, with a 96% confidence level (coefficient of correlation).
## 1 Introduction
[18] evaluated the influences of splitter blades on the flow characteristics of centrifugal pump impeller outlet, and the results show that the addition of splitter blades can optimise the structure of the impeller wake region and improve the velocity distribution of the impeller outlet. [PERSON] et al. [19] assessed the influences of V-shaped trailing edge on the unstable pressure pulsation of centrifugal pump and concluded that the V- shaped trailing edge can effectively reduce the pressure pulsation intensity inside the centrifugal pump. [PERSON] et al. [20] explored the influences of different fillet radii of blade trailing edge on the internal flow of mixed flow pump. They believed that the trailing edge with large radius could effectively improve the speed distribution of the impeller outlet. [PERSON] et al. [21] studied the influences of sinusoidal tubercle trailing edge (STTE) impeller on the unstable pressure pulsation of centrifugal pumps and concluded that the STTE impeller can reduce the pressure pulsation amplitude. [PERSON] et al. [22] investigated the mechanism of wake loss reduction for biomimetic trailing edge and concluded that the wake area for the biomimetic trailing edge case is narrow, and the velocity in the wake recovers more quickly compared with the situations in the three other cases. [PERSON] et al. [23] used a parameterised perturbation method to solve the corresponding nonlinear differential equation. The result shows that the influence of nonlocal parameter is greater at higher flow velocities compared with lower flow velocities. [PERSON] et al. [24] compared and analysed the distribution of trailing edge shedding vortex of modified blade with the original turbine blade and chamfered trailing edge chamfered and concluded that the chamfering of the blade trailing edge can effectively reduce the shedding of trailing edge vortex. [PERSON] et al. [25] experimentally studied the effects of different trailing edge cutting methods on the falling edge vortices of turbine blade trailing edges and concluded that a certain angle of oblique cutting can effectively improve the unstable region of blade trailing edge. Some domestic and foreign scholars have conducted studies on cutting the blade trailing edge to improve the performance and pressure pulsation of centrifugal pumps. Studies on the effects of cutting angle on the unstable flow inside the centrifugal pump under off-design conditions are insufficient and should be conducted. In this study, the influences of the cutting cone angle of blade trailing edge on the performance, unsteady pressure pulsation and unstable flow structure of a centrifugal pump under part-load and overload conditions are studied through large eddy simulation (LES). The results of this study serve as reference in optimizing the shape of blade trailing edge and improving the unstable flow characteristics inside the centrifugal pump. This research is of great significance to effectively suppress the unstable flow and vibration in centrifugal pumps and improve their safety and stability.
## 6 Conclusions  
To summarize, a hybrid analog-digital optical transport topology that is supported by a dynamic, reconfigurable WSS-based optical switching node has been presented. The targeted architecture aims to integrate different transport technologies in a shared optical network segment, contributing to the transition from the existing PtP fiber-based mobile transport networks to dynamically reconfigurable PtMP architectures with the multiplexing of multiple BBUs and radio hardware, towards B5G connectivity. Targeting beyond the lab-scale demonstration of the proposed node, we demonstrated a multi-technology environment, the co-integration of an A-IFoF Ethernet-compatible transceiver, providing converged FiWi connectivity along with both digital and analog transport lanes over the common flexible, hybrid optical transport layer.  
Throughout this work, the implementation path and the performance evaluation of an FPGA-based analog transceiver that is based on a state-of-the-art Xilinx RFSoC platform is extensively described, proving the potential for the successful transmission of reconfigurable bandwidths and modulation formats over fiber and converged FiWi transport links. Thereinafter, we demonstrate the experimental evidence of the dynamic optical routing of both legacy CPRI, 1.5 GBaud A-IfoF-mmWave and 10 Gbps binary optical waveforms, showing acceptable EVM values for the complex radio waveforms and error-free operation of the binary optical streams. Besides these high-capacity transport experiments, 4K video streaming and IP-calls over both the analog and digital lanes were successfully demonstrated, showing the potential of our presented node to dynamically handle high-throughput links and services.  
The reported results denote the strong potential of the proposed hybrid optical topology to support future B5G network reconfigurable transport deployments with bandwidth steering capabilities. The demonstrated transport architecture opens the door to the flexible interconnection of centralized BBU pools and multiple RUs distributed in the field over both standard digital and post-eCPRI analog implementations, depending on the service demand.  
Conceptualization, G.G., G.L. (George Lentaris) and D.A.; methodology, all.; software, K.K., I.S. and E.A.P.; validation, all; formal analysis, all; investigation, K.K., P.T., K.T., I.S. and E.A.P.; resources all; data curation, K.K. and P.T.; writing--original draft preparation, K.K., P.T. and I.S.; writing--review and editing, all; visualization, K.K., P.T., K.T. and I.S.; supervision D.R., D.S. and H.A.; project administration, D.A. and H.A.; funding acquisition, H.A. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the European Commission H2020 5 GPP Project 5 GPHOS, under the grant agreement 761989 and 5G-COMPLETE, under the grant agreement 871900.  
Not applicable.  
**Acknowledgments:** The 60 GHz antenna boards were granted by the WinPhos of Aristotle University of Thessaloniki.  
**Conflicts of Interest:** The authors declare no conflict of interest.
## 4 Simulation Analysis
### Voltage Tracking Experiment  
To verify the practicability of the IFA-LADRC method, four different methods were compared, and step response experiments were conducted for them, respectively. The step response was added at t = 0 s as the input signal of the system. The control effect curves of the four schemes are shown in Figure 7.  
The overshoot of LADRC is significantly smaller than that of the PID controller, as seen in the given voltage step experiment. The optimized FA combined with LADRC can reach the steady-state value the fastest for the system.
# Automatic Identification System for Rock Microseismic Signals Based on Signal Eigenvalues
## 2 Time-Frequency Characteristic Analysis of Microseismic Waveform Signal
### Frequency Domain Analysis of Microseismic Signals
By comparing Table 1 with Figure 11, it can be deduced that the main frequency of the rock blasting signal samples collected this time is mainly concentrated in the range of 0-500 Hz, and the main frequency of the rock fracture event samples collected this time is distributed in the range of more than 500 Hz. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Event Frequency (Hz)** & **0–500** & **500–1000** & **1000–2000** & **2000–3000** & **>3000** \\ \hline Rock blasting & 47 & 2 & 1 & 0 & 0 \\ \hline Proportion & 94\% & 4\% & 2\% & 0 & 0 \\ \hline Rock fracture & 0 & 14 & 15 & 1 & 20 \\ \hline Proportion & 0 & 28\% & 30\% & 2\% & 40\% \\ \hline \end{tabular}
\end{table} 
Table 1: Statistical table of interval of main frequency of rupture and blasting events. Figure 10: Contrast image of marginal spectrum after denoising of rock blasting signal of 33# sensor on 2 July. From the above analysis, it can be observed that the main frequency of the signal after noise reduction can be used as the basis to accurately judge the signal of rock fracture and rock blasting events; however, misjudged individual signals still exist.
# The Role of Elasticity in the Vortex Formation in Polymeric Flow around a Sharp Bend
## 3 Results
### Polymer Flow
#### 3.2.2 Elastic Vortices
It might be possible that this boundary is not asymptotic, and that it is dependent on the Weissenberg and the Reynolds numbers. Take note of the logarithmic \(x\)-axis. The effect of the Weissenberg number on this predicted flow map will be the subject of a follow-up paper. The graph in Figure 14 is the same phase diagram as Figure 13, but the \(x\)-axis is now the Reynolds number (the inverse of the elasticity number for Wi = 1.0). In the figure, it is easier to see that elastic vortices only form at small Reynolds number values and viscosity ratios less than 0.6. As it has already been shown that viscosity ratio has a similar effect on vortex development to that of increasing the Weissenberg number, the question arises as to whether or not \(\beta\) will delay the onset of inertial vortices. Looking at the figure, the boundary of the inertial region is essentially a vertical line (Re = 29-37) indicating that \(\beta\) is predicted to have only a very subtle effect on the onset of inertial vortices. In other words, the Reynolds number is predicted to be the parameter with a primary role in determining the onset of inertial vortices. Figure 14: Phase space diagram, viscosity ratio versus Reynolds number for Wi = 1. Figure 13: Phase space diagram, viscosity ratio versus elasticity number for Wi = 1. Lastly, Figure 15 plots the vortex length of elastic vortices versus the elasticity numbers at which they form for three values of Weissenberg number (Wi = 0.5, 1.0, 1.5) and a viscosity ratio \(\beta\) = 0.1. The figure shows that for elasticity numbers between 0.1 and 10 the size of the elastic vortex is predicted to depend on both the elasticity number, El, and the Weissenberg number, Wi. On the other hand, the figure also shows that for El = 10 and above, the elastic vortex size is predicted to be of the same size for a given Weissenberg number independently of the elasticity number. These predictions indicate that the Weissenberg number plays the primary role in determining the size of the elastic vortex that forms upstream of the bend corner for a fixed viscosity ratio. As discussed earlier, as the Weissenberg number increases so does the size of the elastic vortex. These predictions are also consistent with the experiments of [PERSON] [5] who found that the Weissenberg number is the parameter that determines the presence and size of the elastic vortices forming within the flow of semidilute DNA solutions in a 90\({}^{\circ}\) micro bend channel.
## 5 Results from Experiments Using the Platform
### Setup and Methodology
It is noted that, in the interest of representing the end-to-end delays in a speed-invariant form, their values in the following results are expressed in a normalized way as multiples of the time constant \(r/V\) that determines the time required for refreshing a node's neighborhood (For a node with range \(r\) moving at constant speed \(V\) on a straight line, time equal to \(2r/V\) must elapse before the neighborhood areas spanned by the node at the beginning and end of this time become non-overlapping).