esa-sceva/satcom-chunk-collection huggingface dataset:
# Distributed Unmanned Aerial Vehicle Cluster Testing Method Based on Deep Reinforcement Learning
## 5 Results
### Bandwidth Consumption  
In this set of experiments, we compare the performance of three methods in terms of bandwidth resource cost in distributed networks. As shown in Figure 4, we can observe that three methods, including LogiScope, consume less bandwidth resources in the early stages of the testing task execution. However, with the change in time, the bandwidth resource cost of all three increases. The bandwidth cost of LogiScope in the later stage is gradually higher than the other two methods. For the AutoRunner method, the bandwidth resource cost of UAV communication in a distributed environment is higher in the initial stage, but in the later stage, its value is lower than LogiScope, and it is always greater than the cost of the method proposed in this work. When t = 600 s, the growth rate of the bandwidth resource cost of these two methods began to gradually decline, and the later cost value was lower than LogiScope. For the method proposed in this work, the bandwidth cost is not much different from the other two methods in the early stage, and is gradually lower than the other two methods in the later stage. From the economic aspect of multi-UAV cluster communication bandwidth resources, this method has certain advantages compared with the other two methods. The method proposed in this work is based on deep reinforcement learning, which not only considers the economy of the communication bandwidth resources of multi-UAVs, but also considers the load balancing of the cluster. This algorithm implements many optimization strategies proposed in this paper, and can effectively search for the optimal deployment scheme of the current system testing task. In the long run, we can conclude that the method proposed in this work  
Figure 3: The performance comparison of three methods in terms of load balancing effect.  
is very effective in saving bandwidth resources in the process of distributed testing task processing.
###### Abstract  
Different from the traditional wired network, the fundamental cause of transmission congestion in wireless ad hoc networks is medium contention. How to utilize the congestion state from the MAC (Media Access Control) layer to adjust the transmission rate is core work for transport protocol design. However, recent works have shown that the existing cross-layer congestion detection solutions are too complex to be deployed or not able to characterize the congestion accurately. We first propose a new congestion metric called frame transmission efficiency (i.e., the ratio of successful transmission delay to the frame service delay), which describes the medium contention in a fast and accurate manner. We further present the design and implementation of RECN (ECN and the ratio of successful transmission delay to the frame service delay in the MAC layer, namely, the frame transmission efficiency), a general supporting scheme that adjusts the transport sending rate through a standard ECN (Explicit Congestion Notification) signaling method. Our method can be deployed on commodity switches with small firmware updates, while making no modification on end hosts. We integrate RECN transparently (i.e., without modification) with TCP on NS2 simulation. The experimental results show that RECN remarkably improves network goodput across multiple concurrent TCP flows.  
ad hoc networks; frame transmission efficiency; explicit congestion notification +
Footnote †: journal: Sensors
# Feasibility of Wave Simulation in Typhoon Using WaveWATCH-III Forced by Remote-Sensed Wind
## 2 Data and Method
### ERA-5 Data  
Since 1979, ECMWFs have continuously released atmospheric and marine data (i.e., wind and SWH) for the scientific community [37]. Until now, the spatial resolution of the latest ERA-5 wind and wave data has been 0.25\({}^{\circ}\) with a temporal resolution of 1 h, which is valuable for oceanographic research [38]. However, the ERA-5 wind and wave data during typhoons is significantly underestimated [39], although the TC size asymmetry in global climatology is reliable [40]. Figure 2d,e show the ERA-5 wind and SWH map during Typhoon Mindulle at 18:00 UTC on 26 September 2021, respectively. In this case, the maximum ERA-5 wind speed is 25 m/s, whereas the measurements from NHC are up to 46 m/s. The tropical cyclone reports of NHC contain the most accurate comprehensive information for each storm, including synoptic history, atmospheric statistics, casualties and damages, and the post-analysis best track. The NHC intensity (maximum 1 min average wind associated with the TC at an elevation of 10 m) from the best tracks is estimated using satellite-based techniques, i.e., the Advanced Microwave Sounding Unit and the multiplatform of satellites. Moreover, aircraft reconnaissance data and the Stepped Frequency Microwave Radiometer measurements are also used to reduce the NHC intensity uncertainty. In this study, ERA-5 data are employed to highlight the novelty of this study, i.e., the accuracy of assembling wind and wave parameters simulated by the WW3 model in typhoons because the ERA-5 data underestimate the wind speed under typhoon conditions. In other words, we applied the assembling wind rather than the ERA-5 wind data as the forcing field to improve the accuracy of the wave simulations from the WW3 model.
# Mobility Prediction and Resource-Aware Client Selection for Federated Learning in IoT
## 5 Simulations  
### Setting  
Consider a scenario with 100 clients randomly distributed over a \(2\,\text{km}\times 2\,\text{km}\) area, participating in federated learning (FL) training through a wireless network. A base station (BS) is located at the center of this area to facilitate the exchange of global and local modelsbetween the FL server and the clients. The path loss between each client and the BS is estimated using the formula \(\rho=128.1+37.6d_{u}\)[33], where \(\rho\) represents the path loss and \(d_{u}\) is the distance from the BS to client \(u\). Assuming fast fading is not considered, the channel gain \(g_{u}\) for client \(u\) is primarily determined by the path loss, calculated as \(g_{u}=10^{-\frac{\rho}{\text{th}}}\). Each client transmits at a power of 0.1 watts, meaning \(p_{u}=1\) for all clients \(u\). The bandwidth available to the BS is \(B=1\,\text{MHz}\). Additionally, the CPU frequency \(f_{u}\) and the number of CPU cycles required to process a single sample \(C_{u}\) for each client are randomly selected from two uniform distributions: \(f_{u}\in U(0.1,1)\times 10^{9}\,\text{Hz}\) and \(C_{u}\in U(1,5)\times 10^{7}\) CPU cycles. Other simulation parameters are detailed in Table 2.
_applied sciences_  
_Article_  
Influence of Wheel-Rail Contact Algorithms on Running Safety Assessment of Trains under Earthquakes  
[PERSON] 1, [PERSON] 1,2,3,*\({}^{\text{\textregistered}}\), [PERSON] 1, [PERSON] 1, [PERSON] 1,2,3 and [PERSON] 1,2,3  
1 School of Civil Engineering, Central South University, Changsha 410075, China; [EMAIL_ADDRESS] (G.C.); [EMAIL_ADDRESS] (W.G.); [EMAIL_ADDRESS] (G.Z.); [PERSON]RESS] (L.J.); 1360784187292163.com (B.Y) National Engineering Research Center of High-Speed Railway Construction Technology, Central South University, Changsha 410075, China  
3 Hunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structures, Central South University, Changsha 410075, China  
* Correspondence: [EMAIL_ADDRESS]  
**Abstract:** Accurate running safety assessment of trains under earthquakes is crucial to ensuring the safety of line operation. Extreme contact behaviors such as wheel flange contact and wheel jump during earthquakes will directly affect the running safety of trains. To accurately simulate a wheel-rail extreme contact state, the calculation of the normal compression amount, the normal contact stiffness, and a number of contact points are crucial in wheel-rail space contact modeling. Hence, in order to clarify the applicable algorithms during earthquakes, this paper first introduces different algorithms in three aspects mentioned above. Taking a single CRH2 motor vehicle passing through a ballastless track structure under El-Centro wave excitation as an example, a comparative analysis of wheel-rail contact dynamics and running safety was conducted. The results showed that adopting the normal compression algorithm based on vertical penetration and the consideration of only single-point contact will result in the maximum calculation error of wheel-rail contact force to reach 339.50% and 35.00%, respectively. This significantly affects the accuracy of train safety assessment, while using the empirical formula for wheel-rail normal contact stiffness has relatively less impact. To ensure the accuracy of running safety assessment of trains during an earthquake, it is recommended to adopt the normal compression algorithm based on normal penetration and consider the multi-point contact in wheel-rail contact modelling.  
**Keywords:** running safety assessment; earthquake; wheel-rail contact; contact point; normal compression amount; normal contact stiffness
## 1 Introduction
In addition, to solve the problem of imbalanced data classification, we set the loss function based on the Fisher criterion and propose a two-stage training method based on contrastive loss and the differential evolution algorithm. Experiments on a real-world dataset showed that the proposed method can accurately detect LTE-R cells with degraded communication performance, which could provide an effective technological means for improving the efficiency of LTE-R network operation and maintenance and ensuring the safety of railway operations. The main contributions of this paper can be highlighted as follows. * Based on the principle of shapelet transformation, this paper designed a neural network structure that can extract morphological features of sequence data by transforming CNN neural networks. * In the detection of LTE-R cells with degraded communication performance, considering the class imbalanced problem, a two-stage training method is proposed to make the features extracted by the trained feature extraction network meet Fisher criterion as much as possible. * By using machine learning methods, the mapping relationship between the drive test data and the abnormal release rate of LTE-R core communication services was established, which provides a powerful tool for the operation and maintenance of LTE-R network. The rest of the paper is organized as follows. Section 2 investigates related work. The preliminaries are provided in Section 3. Section 4 introduces the proposed method. Section 5 presents and discusses the experimental results. Conclusions are drawn in Section 6.
## 4 Conclusions and Future Work  
### Conclusions  
Based on high-pressure moving water-jet soil-breaking tests, this paper explored the influences of jet pressure and nozzle moving speed on the morphological characteristics of the erosion surface. An empirical formula was proposed that can predict the geometric shape of the erosion surface. The main findings are as follows:  
Figure 14: Normalised erosion surface morphology.  
Figure 15: Comparative verification of prediction formulas.  
(1) Increases in jet pressure and decreases in nozzle speed during the soil-breaking process expand the geometric shape of the erosion surface. At a given jet pressure, the soil-breaking depth decreases greatly with increases in nozzle speed. At a given nozzle speed, increases in jet pressure generally cause increases in soil-breaking depth.  
(2) Based on erosion theory, it was found that increases in jet pressure greatly reduce the attenuation of erosion speed and then greatly increase the soil-breaking depth. The nozzle moving speed directly determines the initial value of the erosion speed. When the nozzle moving speed is small, the erosion speed attenuation degree is low, and when the nozzle moving speed is large, the erosion speed quickly drops to 0. This leads to greater nozzle moving speeds causing smaller soil-breaking depths.  
(3) The geometric shape of the erosion surface can be divided into straight and curved segments. The proportion of straight lines in the depth, lateral distance, and jet distance was analysed. A model of the maximum soil-breaking depth according to jet pressure and nozzle speed was proposed. Furthermore, it was found that the geometric shape of the erosion surface has self-similarity; accordingly, an empirical formula that can predict the geometric shape of the erosion surface was proposed.
# Degradation Prediction Model for Friction of Road Pavements with Natural Aggregates and Steel Slags
###### Abstract  
Steel production wastes (steel slags) are used more often in asphalt concrete pavements as a valuable replacement for natural aggregates, which are becoming increasingly rare. In this paper authors investigate the polishing characteristics of aggregates, and in particular of steel slags, used in bituminous road surfacing, are a major factor in determining the resistance to skidding. The main purpose of the study is the identification of a suitable degradation model, based on friction indicators, in the laboratory, as well as the comparison of in-situ pavement skid resistance with the cumulative number of passing vehicles over the years. The model predicts the expected resistance to skidding of the road surface based on the knowledge of the polished stone value (PSV) of the aggregates and the expected traffic on the road. In this study, several types of aggregates were compared: steel slag, limestone, limestone and slag mixture, diabase, Criggion stone and basalt. Using a standard PSV test, it was found that the aggregates did not reach the lower value of skid resistance (equilibrium value). The analysis of the British Portable Number (BPN) data versus polishing time allowed to empirically derive a regression model for each investigated aggregate. Hence, it appears possible to define both an investigatory level and threshold level to predict the actual residual life of the pavement from the examination of skid resistance.  
skid resistance; friction; polished stone value; road pavements; steelworks slags; BPN Article
# Fault Estimation for Semi-Markov Jump Neural Networks Based on the Extended State Method
## 3 Main Results  
To analyze the mean square exponential stability and dissipative performance of discrete-time semi-Markov jump neural networks (s-MJNNs) with actuator and sensor faults, this paper adopted the Lyapunov-Krasovskii functional due to its effectiveness in handling systems with time-varying delays, random mode switching, and nonlinearities. By introducing triple summation terms and employing reciprocal convexity techniques, this functional significantly reduces conservatism in deriving stability and dissipativity conditions. Compared with other methods, such as Lyapunov-Razumikhin functions, it provides a more flexible and less conservative analytical framework, making it well suited for observer design in s-MJNNs subject to simultaneous faults, delays, and stochastic switching. Therefore, the Lyapunov-Krasovskii functional serves as a powerful tool to facilitate robust observer design for complex s-MJNNs. Based on this functional, the following subsection presents sufficient conditions for observer design and system performance analysis, ensuring that the proposed estimator can achieve accurate fault estimation under the described challenging scenarios. **Theorem 1. **_Given parameters \(d_{1}>0,d_{2}>0,0<\rho<1\) and known gain matrices, \(\overset{\rightarrow}{K}_{p,\sigma(g)}\), in order to augment s-MJNN (22), there is a strict \((\chi_{1},\chi_{2},\chi_{3})-\varpi\) dissipation performance.
## 4 Discussion  
### Maize Litter Quality Controls N Mineralization  
Soil mineral N content, mineralization, and immobilization strongly depended on maize litter quality. In Control without litter addition, soil NH\({}_{4}\)\({}^{+}\) content decreased, but soil NO\({}_{3}\)\({}^{-}\) content strongly increased due to mineralization and nitrification of soil organic N. Tillage often leads to increased soil mineral N content [40, 41], and net N mineralization from control soils without litter addition has been reported [8, 13, 42]. In Leaf and Root, mineralization was higher than in Control as additional organic N from litter was mineralized. In contrast, addition of maize straw immobilized N, which coincides with the higher C:N ratio in Straw compared to Leaf and Root. In general, immobilization of N follows the addition of litter with C:N ratios > 25:1 [7]. Net N mineralization after addition of maize roots is in contrast to most other studies reporting net N immobilization after addition of maize roots [8, 13, 42, 43]. However, we used maize roots grown in a nutrient solution, which had higher total and water-soluble N content than those reported in other studies [13, 44].
# Principles of Product Design in Developing Countries
## Results
### Communicating Ideas
#### 3.6.1 Community Perceptions of Proposed Design  
A social stigma existed around the installation of solar cookers in Spiti as prior models issued by the government were too fragile with large glass panes and mirrors integrated into the design. When the researcher proposed using polycarbonate (PC) for the design, it was well-received. PC would not be susceptible to breaking when struck by cricket balls; this was the main cause of damage to the government-issued cookers. The glass itself was not the issue, but there was no way to replace broken panes.  
These cooker units were provided as a large scale government operation to provide a healthier and less energy intense option for cooking in rural contexts. The purpose of the cookers not been adequately communicated to the Spitians and therefore they were perceived as somewhat superfluous to their needs. The reliability of the units and ease of replacing broken components was not considered by the government and therefore they tended to remain broken. The reflector component was more valuable as a mirror than the unit was as a cooker. This categorization of community perceptions leads to development principles 2.2 and 2.8 as follow.  
**Deployment Principle 2.2: Involve the end user(s) as much as possible so they feel a sense of ownership for the solution**  
Providing the recipient with a sense of ownership is important for the success of an implemented design. The government-issued solar cookers were not widely used despite their functionality because the people of Spiti had no attachment with them. It is critical that the solution addresses a user identified need or else the relevance of providing the solution is clearly communicated and understood by the intended user.  
Involving the user during the construction phase is beneficial for helping them to understand the functionality of and relationships between different components, to understand how to perform repairs and to also gain a sense of pride and attachment to the design.  
**Deployment Principle 2.8: Community acceptance of the solution is a crucial factor in successful design**  
The solar cookers designed and built by the researcher were completed with assistance from different groups who all voiced particular modifications they wanted to employ from the standard design. For example, users requested an extra base layer of stones to stop water ingress from snow melt, an adjustable reflector to increase energy input, a particular finish to match the aesthetic of the house it was built for. It was important to keep the design flexible enough to facilitate these changes as they allowed user-identified needs to be incorporated. The result was that users had a higher degree of commitment and affiliation with the design than if the final product was simply provided without their input. The local knowledge of the environment also helped refine the design beyond what the researcher was capable of foreseeing.
# Design and Mechanical Properties of Flat Anchorage Limit Plate
## 4 Mechanical Properties of Flat Anchorage Limit Plate
### Tensile Stress Distribution of Double Holes  
After the first hole stretches, the second hole stretches, and many different stretching schemes may arise. Figure 7 shows the stress distribution results of the second hole of the flat anchorage stretching after the first hole stretched. Similarly, with the limit plate, the stress concentration of the flat anchorage stretched on the second hole was substantially alleviated, and the extreme stress value dropped from 519.08 kPa to 485.89 kPa, representing a decrease of 6.4%. Different combinations of tension holes and their corresponding stress extreme results are detailed in Table 3. The above results correspond to tension holes 1 and 2 in Table 3, which means that hole 1 tensioned first, followed by hole 2. The table shows that, overall, the drop in the stress extreme value when the second hole was tensioned was not as large as that when the first hole was tensioned, and the maximum stress results for the different schemes differed little. Relatively, the drop in the extreme stress value was larger when the third hole was tensioned in the first two steps. We calculated the standard deviation of the stress extreme value of the conventional flat anchorage as 5.09 kPa and that of the new flat anchorage system as 7.20 kPa. The influence of the limit plate on the tension results of the different double holes was weak.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Tension Hole Position** & \
\begin{tabular}{c} **Maximum Equivalent Stress of** \\ **Conventional Flat Anchorage (kPa)** \\ \end{tabular} &
\begin{tabular}{c} **Maximum Equivalent Stress of Anchorage** \\ **in New Flat Anchor System (kPa)** \\ \end{tabular} & **Decrease (\%)** \\ \hline
1 & 245.76 & 219.43 & 10.7 \\
2 & 225.74 & 122.07 & 45.9 \\
3 & 207.73 & 107.49 & 48.3 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Extreme value of single-hole tensile stress.  
Figure 6: Tensile stress distribution of hole 1: (**a**) conventional flat anchorage, and (**b**) anchorage of new flat anchor system.  
Figure 7: Tensile stress distribution of holes 1 and 2: (**a**) conventional flat anchorage, and (**b**) anchorage of new flat anchor system.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Tension Hole Position** & \
\begin{tabular}{c} **Maximum Equivalent Stress of** \\ **Conventional Flat Anchorage (kPa)** \\ \end{tabular} &
\begin{tabular}{c} **Maximum Equivalent Stress of Anchorage** \\ **in New Flat Anchor System (kPa)** \\ \end{tabular} & **Decrease (\%)** \\ \hline
1 and 2 & 519.08 & 485.89 & 6.4 \\
1 and 3 & 514.86 & 474.47 & 7.8 \\
1 and 4 & 514.52 & 481.88 & 6.3 \\
1 and 5 & 514.80 & 487.09 & 5.4 \\
2 and 1 & 525.66 & 495.84 & 5.7 \\
2 and 3 & 527.76 & 487.73 & 7.6 \\
2 and 4 & 524.65 & 488.59 & 6.9 \\
2 and 5 & 525.49 & 497.08 & 5.4 \\
3 and 1 & 520.98 & 476.80 & 8.5 \\
3 and 2 & 524.32 & 487.57 & 7.0 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Extreme value of double-hole tensile stress.