esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Materials and Test Methods
### Gradation Design and Specimen Preparation  
A dense asphalt mixture AC-13 was used in this research, and the gradation curves were shown in Figure 1. Two different gradations were used in Figure 1, where BA means basalt asphalt mixture and SS means basalt mixture modified with steel slag. SS asphalt mixture was made by replacing the coarse aggregates with size 9.5-13.2 mm in BA with steel slag (steel slag in other sizes was not available in the laboratory for the time being). Steel slag has different specific gravity from basalt aggregate, thus the coarse basalt aggregates were replaced by steel slag with the same volume. Another two kinds of self-healing asphalt mixtures (SF (steel fibers) and SF + SS) were obtained by adding 6% steel fibers (by volume of bitumen) to BA and SS mixtures.  
The optimum asphalt-aggregate ratio of BA determined using Marshall Mix design method was 4.8%. The optimal asphalt-aggregate ratio of SF, SS and SF + SS were 5.0%, 4.9% and 5.1% [20]. The volume indices of the four asphalt mixtures were tested and calculated according to Chinese standard and shown in Table 2. According to the gradation results, Marshall Specimens were prepared for further tests. Marshall Specimens used for all tests had similar air voids content (difference less than 1%) to avoid its effect on properties of asphalt mixtures.  
In this paper, semi-circle samples were used to study the fracture energy and healing ratios of different asphalt mixtures. The failure form of semi-circular bending (SCB) test is tensile failure, avoiding other types of damage on samples. Therefore, SCB test is usually used to analyze and evaluate the fracture properties of asphalt mixtures [21]. All SCB samples were cut from Marshall Samples with a thickness of 30 mm and a notch of 20 mm in the middle of the radial direction. The samples used for heating and healing tests were the same as SCB samples. The samples for thermal parameters test were cut from Marshall Specimens with diameter 100 mm and height 30 mm.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Mixture types** & **BA** & **SF** & **SS** & **SF + SS** \\ \hline Optimum asphalt content /\% & 4.8 & 5.0 & 4.9 & 5.1 \\ Air voids /\% & 3.53 & 4.36 & 3.79 & 4.25 \\ Voids in mineral aggregates /\% & 14.9 & 14.3 & 14.1 & 13.5 \\ Voids filled with asphalt /\% & 76.3 & 69.4 & 73.4 & 68.6 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Compaction levels and mix design parameters. BA: basalt asphalt; SF: steel fibers; SS: steel slag.  
Figure 1: Gradation curves of basalt asphalt (BA) and steel slag (SS) mixture.
## 2 Methods and Design
### Design of the Fundus Illumination System
#### 2.3.2 Non-Coaxial Lighting System Design  
The illumination part was composed of a light source and a condenser lens and adopted a non-coaxial annular array illumination structure to achieve the suppression of corneal stray light by controlling the range of the pupil spot, the divergence angle of the light source, and the angle of incident light of the light source [22], which effectively avoided the stray light generated by the residual reflection of the optical element.  
In the human eye, the cornea has a high reflectivity of 1.37, and the light incident on the cornea from the front will inevitably produce ghost images [22], which will affect the image quality. As shown in Figure 8, the critical angle of the incident ray was 30 degrees, according to the simulation. The corneal margin incident illumination is shown in Figure 9. In order to solve this problem, non-coaxial surround lighting was used to improve space utilization and avoid occlusion of the imaging system. Four LED light sources were evenly distributed 360\({}^{\circ}\) to form a ring, and the light source illuminated the fundus through the lens and spread the entire pupil, reducing the illumination light received on the cornea, thus preventing the ghost image caused by its reflection. The design results are shown in Figure 10.
## 4 Conclusions  
This study presented the results of an investigation to observe the influence of incorporating QRD wastes as a binding agent on the fresh and mechanical properties at ambient curing conditions of FA- and SG-blended GPC mixes, which are also exposed to elevated temperatures to observe their residual strength properties. The following conclusions can be drawn from the results of the study:  
1. Increasing the QRD replacement resulted in decreasing the workability of the QFS-GPC mixes.
2. The mechanical strength of the QFS-GPC mixes generally increased by increasing the QRD content from 0% to 15%, while beyond this replacement level, i.e., 20%, strength decreased.
3. GPC-D specimens prepared with 50% FA, 35% SG, and 15% QRD yielded the maximum compressive strength amongst all the QFS-GPC specimens at 7, 28, and 56 days of ambient curing. The maximum splitting tensile and flexural strength was also observed in GPC-D specimens at ambient curing conditions.
4. The residual compressive strength of the QFS-GPC mixes decreased with an increase in QRD content from 0% to 20%. The weight loss after heating to elevated temperature is also consistently more in QFS-GPC specimens with increasing QRD content. It can be observed, therefore, that the QFS-GPC mixes have relatively inferior strength performance under elevated temperature as compared to OPC concrete.
5. The XRD results show that mix GPC-D has the maximum strength due to the formation of crystalline phases while in other mixes (OPC, GPC-A, GPC-B, GPC-C, and GPC-E), mostly amorphous phases were identified.  
It can be inferred from this study that ternary blended GPC mixes of good quality can be produced at ambient curing conditions by incorporating the recycled QRD wastes. A compressive strength of 20-33.5 MPa can be achieved with 50% FA and by replacing the remaining 50% SG content with 5-20% QRD content. The optimum content of source materials for ternary blended QFS-GPC mixes is 50% FA, 35% SG, and 15% QRD, which can yield a compressive strength of 33.5 MPa, a split tensile strength of 2.12 MPa, and a flexural strength of 3.62 MPa. This optimum mix can be used for cast-in-situ applications at ambient curing conditions; however, the structural member may require fireproofing treatment.  
Conceptualization, K.H. and F.B.; methodology, K.H., F.B. and R.M.W.; software, K.H. and M.A.M. and E.E.H.; validation, F.B., M.I. and N.A.; formal analysis, K.H. and Z.X.; investigation, K.H. and R.F.T.; data curation, K.H.; writing--original draft preparation, K.H.; writing--review and editing, F.B, M.A. and F.A.; supervision, F.B. All authors have read and agreed to the published version of the manuscript.  
This research was funded by [Taif University, Researchers Supporting Project] grant number [TURSP-2020/196].  
Not applicable.  
All the data is available within this manuscript.  
Authors would like to acknowledge the finical support provided from Taif University Researchers Supporting Project Number (TURSP-2020/196).  
The authors declare no conflict of interest.
# Graphene Oxide Adsorption Enhanced by Attapulgite to Remove Pb (II) from Aqueous Solution
###### Abstract  
To improve the adsorption and separation efficiency of lead-containing wastewater by graphene oxide (GO), attapulgite (ATP) was used through a simple hydrothermal reaction. The prepared GO was characterized by SEM, TEM, FTIR, and XPS. The adsorption properties of the prepared GO were investigated. The maximum adsorption capacity of Pb\({}^{2+}\) on as-prepared GO at pH 5 and 25 \({}^{\circ}\)C was 450.9 mg/g. It is concluded that the as-prepared GO can be used as a high-efficiency adsorbent for lead-containing wastewater.  
graphene oxide; attapulgite; lead ion; adsorption Article
# AccFlow: Defending against the Low-Rate TCP DoS Attack in Drones
## 3 AccFlow Design
### Aggressive Detection
Although Aggressive Detection proves to be a straightforward and precise defense mechanism against the ideal low-rate TCP DoS attack, it necessitates a substantial ULR (Upstream Loss Rate) gap to effectively distinguish between the attacking flow and legitimate flows. Finding a reasonable ULR (Upstream Loss Rate) threshold can be a challenging task, particularly when attackers continuously alter their strategies to reduce the ULRs of their flows. For example, instead of launching a single attacking flow, attackers can divide their traffic into \(N\) flows and synchronize them to create periodic burst flows. The usage rate of each individual attacking flow decreases by a percentage of \(\frac{N-1}{N}\), including its ULR. As the  
Figure 4: Loss rate and uniform loss rate of each flow. number of synchronized attacking flows increases, the ULR gaps between legitimate flows and attacking flows diminish, rendering it more challenging for the controller to detect the attacking flows. However, it is important to note that even as the ULR gaps decrease, the network still experiences the same volume of attacking traffic, allowing the DoS attack to remain effective. We present the shortcoming of Aggressive Detection in Figure 5. Note that when the attackers split their traffic into 50 synchronized flows, the ULR differences between attacking flows and legitimate flows are close to zero. To tackle such distributed attacks, we design the Early Drop module in the next subsection.
## 2 Problem Formulation
### WIM-WIM System (Finland)  
The WIM-WIM system [63] measures the transfer loads of wheels on rails in order to determine the uneven loading and overloading of wagons, as well as the impact of wheels with a flat spot or significant oval shape. The system is based on tensometric sensors, and measurements can be made on trains running faster than 250 km/h.  
The system can measure and determine the following:  
* wheel impact force on the rail;
* dynamic rolling angle of the wheels on the rail and the relationship of this angle with the lateral interaction forces of the wheel and the rail;
* the weight of individual rolling stock units, while also determining the uneven loading of wagons.  
If the impact of the wheel on the railway track exceeds 45 tf (tf--tone force, 1 tf = 9.807 \(\times\) 10\({}^{3}\) N), the train is stopped, and wheelsets are replaced. When the impact load is in the range of 27 to 45 tf, a notification is given that this wheel needs to be repaired.
# High-Speed Directly Modulated Laser Integrated with SOA
## 4 Conclusions  
In summary, we have developed a unique DML including a PCG and integrated SOA, attaining a record bandwidth of 25.8 GHz, an output power surpassing 25 mW, and an SMSR above 44 dB. Fabricated using cost-effective IAL technology, this device streamlines manufacturing and avoids heterojunction losses. Significantly, the suggested DML demonstrates a reduced TDEC compared to traditional DMLs, suggesting increased signal transmission capabilities. Our results demonstrate the efficiency of the  
Figure 6: **(a)** Comparison of TDEC between the DML with and without SOA at a modulation current of \(I_{M}=60\) mA. **(b)** Relationship between TDEC and \(I_{S}\) for the DML with SOA at \(I_{M}=60\) mA under different filter bandwidths. **(c)** Eye diagrams of signal transmission for the DML without SOA (BTB) and the DML with SOA (BTB, 2 km, and 10 km Transmission) at \(I_{M}=60\) mA and 10.5 GHz filter bandwidth.  
SOA's quasi-high-pass filter effect in simultaneously enhancing bandwidth and output power, with the PCG maintaining outstanding mode stability. This integrated laser architecture efficiently addresses critical constraints of conventional DMLs in bandwidth, power, and mode stability, while delivering a streamlined and cost-reduced fabrication approach. This discovery lays the door for the next generation of high-performance, directly modulated lasers.  
Conceptualization, Y.L. and D.B.; methodology, J.C.; software, X.C.; validation, J.C., J.B., and D.B.; formal analysis, H.Y. and W.L.; investigation, X.Z.; resources, Y.J.; data curation, K.C.; writing--original draft preparation, J.C.; writing--review and editing, Y.J.; visualization, X.Z.; supervision, M.L.; project administration, N.Z.; funding acquisition, Y.L. and Y.J. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the National Key Research and Development Program of China (2023 YFB2805202 (Y.L.), 2023 YFB2806400 (Y.J.)).  
Not applicable.  
Data Availability Statement: Data are contained within the article.  
The authors declare no conflicts of interest.
## 1 Introduction
However, most scholars performed parametric analyses, but did not investigate the underlying reasons for impact on the surface settlement trough induced by the pile-soil-tunnel interaction mechanism. In view of the aforementioned issues, it is of great significance to study the restraint mechanism of isolation pile on soil displacement induced by shield tunnelling, which can help us better predict the surface settlement trough and accurately evaluate the protection effect of isolation pile on the adjacent buildings. The outline of this paper is as follows: firstly, the Loganathan formula [19] based on virtual image principle is adopted to calculate the surface settlement trough without isolation piles. On this basis, Melan solution [20; 21] in the semi-infinite plane based on elasticity is introduced to derive the ultimate surface settlement trough from the perspective of negative friction of pile edge. Secondly, an engineering case is found in the Changsha Metro Line 5 from East Laodong Road Station to Huaya Station, where shield tunnelling passes through Huaya International Hotel at a close distance. Thirdly, a two-dimensional numerical model is established based on FDM-DEM coupling, with the constraint effect of the isolation pile on the surface settlement trough reflected through the friction effect between particles and the wall. Finally, the applicability and reliability of the analytical and numerical solutions are verified by comparing field measured data, which has significant engineering guiding reference in analyzing such projects.
## 5 Conclusions  
This performance-based design process was confined to reinforced concrete column members for the single degree-of-freedom structure, which can provide a basis for the study of performance-based design methods for multiple degree-of-freedom structures. The main conclusions and suggestions are as follows:  
1. The corresponding relationship between the damage index and construction member parameters and seismic parameters was established.
2. The increase in stirrup ratio can slow down the damage, and the slowing effect was initially fast and then slow. When the reinforcement is doubled, the damage index decreased by 0.063.
3. The longer the earthquake duration was, the more serious the damage was, and this phenomenon was more obvious when the ductility coefficient was larger. With the increase in the ductility coefficient, the damage increased continuously. Therefore, an effective way to decrease the damage is by controlling the ductility coefficient. Among all the influencing factors, the fundamental period and seismic intensity contributed more significantly to the damage indicators.
4. This design process can be used in the performance-based design of reinforced concrete column members.
5. The design method based on the damage index can make up for the deficiency where the design method based on the ductility coefficient does not consider the earthquake duration.  
Conceptualization, Y.W. and Z.L.; methodology, J.G.; software, J.G.; validation, Y.W., J.G., and D.Z.; formal analysis, Y.W.; investigation, Y.W.; resources, Z.L.; data curation, D.Z.; writing--original draft preparation, Z.L.; writing--review and editing, Y.W.; visualization, Y.W.; supervision, J.G.; project administration, Z.L.; funding acquisition, Y.W. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China, grant number 50908022; the Natural Science Foundation of Hunan Province, grant number 2022 JJ40023; and the Hunan University Students Innovation and Entrepreneurship Training Program Project, grant number S202211527024.  
The data presented in this study are available on request from the corresponding author.  
The authors declare no conflict of interest.
## 2 Foundational Concepts and Technologies
### Multi-Agent Systems  
Incorporating multi-agent systems facilitates efficient task distribution and collaboration, allowing specialized agents to handle distinct aspects of complex analytical processes. By enabling agents to work concurrently and share insights, this architecture enhances scalability, adaptability, and overall performance in high-demand environments like financial market analysis.  
Figure 7: LangGraph RAG algorithm, adapted from Ref. [31].
# Single-Channel Blind Source Separation of Spatial Aliasing Signal Based on Stacked-LSTM
## 5 Experiment
### Case Study 1: Effect under Pure Environment  
Experimental purpose: To compare the performance difference between Stacked-LSTM network and ICA, NMF, TasNet, Wave-U-Net, and ConvTasNet under ideal trans \begin{table}
\begin{tabular}{l c c c} \hline \hline \multicolumn{1}{c}{**Method**} & **Source Signal** & **SNR (Bb)** & **Stride (dB)** \\ \hline
1 & BPSK & 5\(\sim\)30 & 5 \\
2 & BPSK, BPSK & 5\(\sim\)25 & 5 \\
3 & QPSK & 12\(\sim\)22 & 2 \\
4 & Radar signal & 10\(\sim\)30 & 0.5 \\
5 & EEG, ECG & / & / \\
6 & Speech signal & \(-\)6\(\sim\)9 & 3 \\
7 & Speech signal & / & / \\
8 & Speech signal & / & / \\
9 & Stacked-LSTM & BPSK, BPSK, 16 QAM, 64 QAM, PAM4 & 5\(\sim\)20 & 2.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Single-channel BSS algorithms. Figure 5: Experimental flowchart. mission conditions with high signal-to-noise ratio SNR = 20 dB. The basic parameter configurations of the six blind source separation methods are shown in Table 2.  
As traditional machine learning methods, ICA [9] and NMF [10] are two classic algorithms in the field of blind source separation. ICA uses dynamic embedding to convert single-channel observation data into multi-channel data for separation. It has superior performance in positive and over-determined separation, and has poor separation accuracy in single-channel under-determined separation. NMF calculates the basic matrix and coefficient matrix of the source according to the KL divergence minimization to achieve signal separation. Such traditional algorithms are equivalent to shallow models and do not extract deep features of the signal. As three deep learning separation methods, TasNet [11], ConvTasNet [12] and Wave-U-Net [13] can realize single-channel blind source separation of signals. In the TasNet network, a separation modules with three-level structure is adopted. In the separation module, Long Short-Term Memory (LSTM) network is used in each block, and its large number of parameters significantly increase its computational cost. In the 1-D block of the ConvTasNet network, a deep separable convolutional convolution is used, and the convolution kernel is an expanded convolution with different expansion rates to obtain features of different time scales. However, when the receiving field of one-dimensional convolution is smaller than the sequence length, sequence-level modeling cannot be performed. In the Wave-U-Net network, time domain convolution is used to process the time series context, combining high-level and low-level features on different time scales. The sampling rate of the original signal is used as the resolution in each feature map generated by convolution, so the memory consumption is high. The experimental results are shown in Table 3. It can be seen that the Stacked-LSTM method had the best performance, with a loss value of \(-18.67\) dB, which was 2.62 dB lower than that of ConvTasNet. Under ideal transmission conditions, the comparison result of
# Effects of Simulated Nitrogen Deposition on the Bacterial Community of Urban Green Spaces
## 3 Results
### Effects of Soil Chemical Properties on the Soil Bacterial Diversity and Community Composition  
The correlations of bacterial diversity indices and main phyla with soil properties are shown in Figure 5. Values of the Chao1 index were positively correlated with soil pH (\(p\) < 0.001) and TC contents (\(p\) < 0.001) and were significantly negatively correlated with NH\({}_{4}\)+-N (\(p\) < 0.001), and TN contents (\(p\) < 0.05). Values of the Shannon index were positively correlated with soil pH (\(p\) < 0.001) and TC contents (\(p\) < 0.05) and were signifi  
Figure 4: Differences in bacterial community composition among N treatments across different sampling times. PERMDISP2 visualizes the distances of each sample to the group centroid in a principal coordinate analysis (PCoA) and provides a \(p\)-value for the significance of the treatments.  
cantly negatively correlated with NH\({}_{4}\)+-N (\(p\) < 0.001). The majority of the predominant phyla showed a significant correlation with certain soil chemical properties, whereas only the phyla. The relative abundances of Proteobacteria were negatively correlated with soil pH. Actinobacteria and Firmicutes were also negatively correlated with soil pH, whereas they showed a positive correlation with the NH\({}_{4}\)+. The abundances of Acidobacteria, Planctomycetes, Latescibacteria, Verrucomicrobia, and Parcubacteria presented a positive relationship with pH, while they showed a negative relationship with NH\({}_{4}\)+-N. Nitrospirae and Gemmatimonadetes did not exhibit a significant correlation with any of the soil parameters.  
The Mantel test explored the correlation between bacterial communities and soil properties (Table 2). The correlation coefficients, in decreasing order of absolute values, were, for positive correlations: pH, NH\({}_{4}\)+-N, and TN; while for negative correlations: TC, and NO\({}_{3}\)-N. Two of the most important factors, pH (\(p\) < 0.05) and NH\({}_{4}\)+-N (\(p\) < 0.05), were closely correlated with bacterial community composition. The non-opposite trend for pH and ammonium appearing from Table 2 is, in our view, due to the fact that, although ecological diversity indexes are abated by increasing ammonium, and decreasing pH, a number of numerically relevant phyla are enhanced. Thus, the overall value of community  
Figure 5: Pairwise correlations of bacterial diversity indices and abundant phyla (relative abundance >1%) with soil properties. The Pearson correlation coefficient was used to test the relationships between soil properties and alpha diversity indexes. Spearman correlation coefficients were utilized to assess the correlations between soil properties and bacterial main phyla.  
structure is not as impaired by such substitutions in relative abundance as the Simpson and evenness parameters are.  
It must be observed however that in Table 2, while for the pH parameter, the \(p\) value is very significant, for the ammonium nitrogen, significance is borderline, and the \(r\) value is very low.
## 3 Trajectory Tracking Controller Design Based on LADRC
### LADRC Design Process for Trajectory Tracking  
Based on the guidance of the above law, it is necessary to develop a corresponding controller that can effectively regulate the steering gear of the parafoil system. This controller is essential for ensuring accurate tracking of the guidance yaw angle. Additionally, another controller is required to calculate the appropriate thrust, enabling the parafoil system to maintain a stable altitude during flight. In this paper, an LADRC controller is chosen for several reasons. One notable advantage of LADRC is its independence from model information, allowing it to handle unknown disturbances effectively. Moreover, LADRC exhibits inherent decoupling characteristics, effectively addressing the challenge of coupling between horizontal trajectory tracking and altitude tracking. This makes LADRC a suitable choice for the control system design in this study.