esa-sceva/satcom-chunk-collection huggingface dataset:
# A Predefined-Time Control for the Laser Acquisition in Space Gravitational Wave Detection Mission
## 3 Mathematical Model
### Topological Relationship for the Satellite Platform  
One satellite which carries two telescopes that each have two DOFs is a typical multi-body system. We use the graph theory to describe the interconnection of these bodies mathematically. The topology of the satellite platform is shown in Figure 8. The satellite body is numbered 0, the telescope swing mechanisms are numbered 1 and 3 and the telescope bodies are numbered 2 and 4. These numbers correspond to the coordinate system numbers which is showed in Figure 9.
## 5 Conclusions  
A technique to compensate for angular misalignments of a small cylinder in the stitching linear-scan method has been proposed. In the proposed technique, the angular misalignment of a small cylinder about the \(X\)-axis was evaluated by measuring the inclination angle of a workpiece holder surface by using the stylus profiler, while the one about the \(Z\)-axis was evaluated by using the data of two arc-profiles obtained at different axial positions of the workpiece. Experimental results demonstrated that the proposed method can evaluate the angular misalignments with a repeatability/reproducibility of better than 0.01\({}^{\circ}\), which is enough to suppress the measurement uncertainty of a workpiece diameter as well as roundness. Measurement of a pin gauge having a diameter and a length of 3 mm and 5 mm, respectively, was carried out, and the feasibility of the proposed technique was verified. Furthermore, measurement uncertainty analysis was carried out through numerical calculations based on a Monte Carlo method to theoretically verify the feasibility of the stitching linear-scan method. Expanded uncertainties for workpiece diameter measurement and roundness measurement were evaluated to be 0.032 \(\upmu\)m and 0.024 \(\upmu\)m, respectively.  
Conceptualization, W.G. and Y.S.; methodology, T.S., Q.L. and W.G.; software, T.S. and Q.L.; validation, Y.S., W.G. and H.M.; formal analysis, T.S., Q.L., Y.S. and W.G.; investigation, T.S., Q.L. and Y.S.; resources, Y.S. and W.G.; data curation, T.S., Y.S. and W.G; writing--original draft preparation, Q.L. and Y.S.; writing--review and editing, W.G. and Y.S.; visualization, W.G. and Y.S.; supervision, W.G.; project administration, W.G.; funding acquisition, W.G., Y.S. and H.M. All authors have read and agreed to the published version of the manuscript. This work is supported by the Japan Society for the Promotion of Science (JSPS) 15H05759 and 20H00211.  
The authors would like to thank [PERSON] for his help in the preparation of the experimental setup.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
## 4 System under Study with PR Controller  
A simplified DG under consideration is represented in Figure 8 to show the DC link voltage, inverters, the Park or Clarke transformations, and the local load, in a three phase structure.  
Figure 6: The frequency measured using two kinds of PLL in load variation condition.  
Figure 7: The frequency measured using two kinds of PLL in fault condition.  
In this situation, the demonstration in the discrete-time domain is based on the Z-transformation associated to the inductor current \(G_{p}(s)\) along with the sample and hold effect [37], which is given by:  
\[G_{p}(z)=\frac{I_{L\alpha\beta}}{V_{i\alpha\beta}}=\left(1-z^{-1}\right)Z\left\{ \frac{G_{p}(s)}{s}\right\}=\frac{1}{R_{f}}\frac{\left(1-e^{-\frac{T_{z}}{t_{p}} }\right)^{-1}}{1-e^{-\frac{T_{z}}{t_{p}}}z^{-1}} \tag{3}\]  
where \(I_{L\alpha\beta}\) and \(V_{i\alpha\beta}\) are the inductor current and input voltage in the z-domain, respectively, and \(\tau_{p}=L_{f}/R_{f}\) is the plant time-constant. The state space equations of system are mathematically formulated by:  
\[\begin{split}\frac{d}{dt}v_{c}(t)=\frac{1}{C_{f}}i_{L}(t)\\ \frac{d}{dt}i_{L}(t)=\frac{1}{L_{f}}(v_{i}(t)-R\;i_{L}(t)-v_{c}(t ))\end{split} \tag{4}\]  
If the expressed in Equation (4) are transformed to the Laplace domain including the effects of initial conditions, we could re-write by:  
\[\begin{split} V_{c}(s)=\frac{\omega_{n}^{2}}{s^{2}+2\zeta\omega_ {n}+\omega_{n}^{2}}\Theta(s)\\ \Theta(s)=\frac{v_{i}(t=0)}{s}+\frac{sv_{C}(t=0)+\dot{v}_{c}(t=0 )}{\omega_{n}^{2}}\end{split} \tag{5}\]  
\[\begin{split} I_{L}(s)=\frac{\omega_{n}^{2}}{s^{2}+2\zeta\omega_ {n}+\omega_{n}^{2}}\Lambda(s)\\ \Lambda(s)=C_{f}v_{i}(t=0)+L_{f}C_{f}\dot{v}i_{L}(t=0)-C_{f}v_{c} (t=0)\end{split} \tag{6}\]  
where:  
\[\begin{split}\zeta=\frac{1}{2\omega_{n}}\frac{R_{f}}{L_{f}}\\ \omega_{n}^{2}=\frac{1}{L_{f}C_{f}}\end{split} \tag{7}\]  
where \(\omega_{n}\) is the natural frequency of the system and \(\zeta\) represents the damping factor. To determine the reference current and voltage for the voltage source inverter (VSI), according to Figure 8:  
\[\begin{split}\ddot{v}_{L\alpha\beta}^{*}=\left(v_{C\alpha\beta}^ {*}-v_{C\alpha\beta}\right)G_{v}(z)\\ gate_{pulses}=\left(\dot{v}_{C\alpha\beta}^{*}-i_{C\alpha\beta} \right)G_{i}(z)\end{split} \tag{8}\]  
Figure 8: A sample DG and RLC filter feeding a load.
# Advanced Micro/Nanocapsules for Self-Healing Coatings
## 4 Classification of Self-Healing Coatings Based on the Polymeric Matrix
### Elastomers
#### 4.3.2 Poly1,3-Diene-Based Self-Healing Coatings  
Polybutadiene and polyisoprene are both types of synthetic rubbers with enhanced flexibility and elasticity. Polyisoprene can exhibit self-healing properties that are assigned to reversible covalent bonds, such as the incorporation of Diels-Alder or disulfide bonds into the polymer structure, physical cross-links such as the presence of ionic interactions or hydrogen bonds, and molecular mobility at elevated temperatures, promoting a healing effect. The self-healing properties of polybutadiene are ascribed to microphase separation, creating domains that repair damage via the mobility of the rubbery phase, reversible networks of metal-ligand interactions or hydrogen bonds, and plasticization [65; 66; 67].  
The integration of self-healing agents into coatings has emerged as a transformative approach to enhancing their durability, particularly in combating environmental degradation and extending their service life. Foundational studies have demonstrated the potential of these coatings to autonomously repair damage, thereby mitigating the adverse effects of environmental factors such as moisture, UV radiation, and pollutants [37]. Recent advancements have refined the design and efficiency of these self-healing systems by incorporating various healing agents, such as microcapsules, vascular networks, and intrinsic healing polymers [68]. These developments have not only improved the mechanical properties and longevity of the coatings but have also shown significant promise in reducing the environmental impact of maintenance and repair activities [69]. For instance, self-healing coatings have been particularly effective in addressing metal corrosion, which has substantial economic and environmental consequences [25]. By autonomously repairing microcracks and preventing the propagation of damage, these coatings reduce the frequency of manual interventions and associated resource consumption, thereby offering a sustainable solution for long-term protection. Moving forward, it is crucial to continue optimizing these systems to enhance their healing efficiency and broaden their applicability across different materials and environments.
## 4 Test Phenomena Analysis
### Analysis of the Test Phenomena
#### 4.2.2 The Development of the Multi-Level Toppling-Bending Zone  
The model with a slope angle of 75\({}^{\circ}\), different from the other two slope models, generated a new secondary toppling-bending zone with increasing centrifugal acceleration after the first toppling-bending zone formed. The secondary toppling-bending zone was located inside the toppled rock mass, the above rock strata toppled more strongly, and the dip angle of the rock strata was further reduced. The interlayer tensile effect intensified, and the number and width of the tensile cracks increased. In addition, the rock mass near the free face of the slope broke and collapsed towards the slope foot. The multi-level rupture surface appearing in this experiment was consistent with the phenomenon of multiple rupture zones of rock strata exposed in the adit exploration of the Gushui Hydropower Station. This indicated that the steeper the free-face is, the higher probability that the occurrence of multi-level toppling during the evolution process of the toppling slope will occur.  
Furthermore, the centrifugal acceleration value at the beginning of the slope foot rupture was taken as the critical acceleration value of the toppling failure and as a criterion for judging the difficulty degree of the toppling failure. Under the same dip angle of the rock stratum, the influence of the slope angle on the development of toppling-bending zones was relatively sensitive. The larger the slope angle is, the smaller the critical acceleration needed for toppling and breaking and the more readily toppling failure occurs in the slope. The morphology of the toppling-bending zone can explain this phenomenon: the larger the slope angle is, the thicker the rock strata above the toppling-bending zone, and the larger the pressure of the slope foot from the overlying rock strata. Then, the rock strata of the slope foot more easily meets the ultimate strength, breaks and fails as the centrifugal acceleration increase.
## 2 UWB Signal Processing Steps
### Target Detection
#### 2.2.2 CLEAN Algorithm  
After the clutter-free signal is amplified for the path loss compensation, the resulting signal will be the input of the CLEAN algorithm for target detection. The CLEAN algorithm is defined by Algorithm 2:  
```
(1) Input:\(v(k)\): Waveform template; \(T_{clean}\) : detection threshold, \(x(t)\): data frame (2) Initialize: Form initial residual waveform \(d_{0}(t)=x(t)\). Set iteration counter \(i=0\). (3) Signal analysis: Compute cross-correlation \(r_{\text{rd}}(\tau)\) between \(v(t)\) and \(d_{i}(t)\);  The time-index associated to the maximum magnitude of \(r_{\text{rd}}(\tau)\) is the \(i^{th}\) estimated TOA: \(\dot{n}i(t)=argmax\ \left|\ \right.rrd(\tau)\left|\ \right.\).  The cross-correlation at \(\dot{n}\)i(t) is the ith estimated amplitude: \(\dot{\text{ai}}\)(t) = rvd(\(\dot{n}\)i(t)).  If the \(\dot{a}_{i}(t)\)\(>T_{clean}\):  a Increment the iteration counter:\(i\gets i+1\).  b Update residual waveform:\(d_{i}(t)=d_{i-1}(t)-\bar{a}_{i}(t)v(t-\bar{n}_{i}(t))\).  c Iterate: Go to step 3. (4) Stop
```  
**Algorithm 2** CLEAN Algorithm  
Thus, the CLEAN Algorithm will give one TOA for every target, even when it is a distributed target. This TOA will be used to calculate the position (distance) of the target.  
\[R(t)\ =\ \bar{n}(t)\times c/2, \tag{12}\]  
where \(R\) denotes the distance between the radar and the target, \(\bar{n}\) is the \(TOA\), \(c\) is the speed of light and \(t\) denotes the observation time which is herein associated with the frame number.
## 5 Conclusions  
This paper studies a relay-aided hybrid FSO/RF cooperation system to further improve the performance of the FSO system. By analyzing the end-to-end instantaneous SNR of the hybrid direct link and the relay-aided hybrid system with the subcarrier modulation scheme, new mathematical expressions of the ABER and outage probability are derived. Through system simulation, the effects of different turbulence intensity, pointing errors, modulation modes, detection schemes, and RF fading parameters on the hybrid direct link and the relay-aided hybrid system are compared and analyzed.  
According to the research and analysis of this paper, we can obtain some important conclusions. Compared with the hybrid direct link, the relay-aided hybrid system can further improve the performance of the system over atmospheric turbulence and pointing  
Figure 11: Relationship between performance metrics and the SNR of the relay-aided hybrid FSO/RF system and hybrid direct link with different direct distances and average SNR of the RF sub-link. (a) BER. (b) OP.  
Figure 10: Relationship between performance metrics and the SNR of the relay-aided hybrid FSO/RF system and hybrid direct link with different direct distances. (a) Bit error rate (BER). (b) Outage probability (OP).  
errors. By selecting the appropriate subcarrier modulation mode and detection scheme, the communication performance of the hybrid direct link and the relay-aided hybrid system can be improved. For example, the performance of the system with CBPSK modulation and the heterodyne detection scheme is the best in this paper. For the relay-aided hybrid FSO/RF system, the communication performance of the system can be improved by increasing the number of paths and reducing the number of hops, but the increase in the number of hops can increase the transmission distance and coverage. The influence of the RF fading parameter \(m\) on the hybrid direct link and the relay-aided hybrid system is obvious. The relay-aided hybrid system can greatly compensate for the deterioration of the system performance caused by pointing errors. The change in direct distance has little impact on the performance of hybrid direct links and relay-aided hybrid systems, while the change in the SNR of RF sub-links has a significant impact on their performance.  
Conceptualization, Y.W.; methodology, Y.W.; software, Y.W. and G.L.; validation, Y.W.; formal analysis, Y.W.; writing--original draft preparation, Y.W. and D.K.; writing--review and editing, Y.W. and D.K.; supervision, D.K. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Science Foundation of China (No. 62001333), the National Incubation Project of Wuhan Textile University (No. 20220609), and the 2023 Hubei Provincial Natural Science Foundation (Youth Fund): [PERSON], Wuhan Textile University, Incentive Mechanism Design for Asynchronous Federated Learning in Edge Network (Project publicity number: 291).  
Not applicable.  
The authors declare no conflict of interest.
## 5 Deployment Challenges
### Secured Content Management  
The distributed nature of a content-centric network makes secured content management difficult. The proposed architecture must guarantee content integrity, authentication of the source, Digital Right Management (DRM), _etc._, Additionally, user's authorization to request the content and tracking consumption for billing should be in place. Traditional CDNs [10] support different security services, including authentication, authorization, integrity protection and billing. Furthermore, in recent studies [12], different innovative approaches, including self-certified, context-based (_i.e._, security level depends on the context of a content) security techniques can be found. In the proposed model, the direct involvement of the ISPs allow them to engage in secured content delivery, also providing DRM.
## 4 Experimental Results  
Speech signals spoken by ten speakers (five male and five female speakers) in Mandarin Chinese were employed for testing the system performance. The speech signals were interfered by factory, F16 (recorded inside the cockpit of a F16 aircraft), white, car, babble (speech-like) and helicopter (recorded inside the cockpit of a helicopter) noise signals, which were all extracted from the Noisex-92 database. Three input average segmental SNR levels (0, 5 and 10 dBs) were utilized to evaluate the performance of denoising systems. The sampling frequency and the frame size are 8 kHz and 256 (with 50% overlap), respectively.  
We performed the average of segmental SNR improvement (_Avg_SegSNR_Imp) and perceptual evaluation of speech quality (PESQ) [14; 15] to evaluate the system performance for speech denoising. In addition, waveform plots and spectrogram observation were also conducted for performance evaluation. The original MCRA noise estimator [3], the forward-backward MCRA (FB_MCRA) noise estimator [8] were conducted for performance comparison. A three-step-decision gain factor [16] was employed to perform speech denoising for various noise estimators. Some samples of denoised speech can be downloaded via the web links shown in Appendix A.
## 3 Results
### Prediction of Membrane Wetting with Sodium Dodecyl Sulfate
#### 3.2.3 Liquid Entry Pressure  
Figure 4 presents the LEP for the three different membranes for a variety of SDS concentrations and 35 g/L NaCl. Up to a concentration of 50 mg/L SDS no immediate breakthrough of the liquid was observed for a pressure up to 4 bar for all three membranes. The maximum pressure of the experimental setup was 4 bar. Higher liquid entry pressures are therefore not measurable, which is indicated by the hatched bars. The PE and PES membrane shows a strong decline of LEP at higher SDS concentrations. However, in contrast to what was expected based on the surface tension and contact angle measurements, an LEP of 1.8 bar was still achieved at 150 mg/L SDS for the PE membrane. Neither the PES nor the PTFE membrane showed a severe decrease in contact angle and surface tension. Nevertheless, the lowest LEP of 1.4 bar at 150 mg/L SDS is observed for the PES membrane, while the PTFE membrane still shows a liquid entry pressure of 3.5 bar. This difference in behavior of the LEP is not expected based on the contact angle measurements, but can be explained due to a difference in pore size (Table 1), which is inversely correlated to liquid entry pressure (Equation (1)). The PES membrane has the highest maximum pore diameter of 0.59 \(\upmu\)m, while the PTFE membrane has a maximum pore diameter of only 0.19 \(\upmu\)m.  
To measure the time dependence of the wetting an additional experiment was carried out. The membrane was placed inside the pressure cell and a constant pressure of 1 bar was applied, using a feed liquid of 150 mg/L SDS and 35 g/L NaCl. The pressure of 1 bar was selected based on the expected pressure drops in a full-scale MD module [36; 37]. The PTFE membrane does not show any liquid penetrating the membrane after 30 min, whereas the PE and PES membranes show liquid breakthrough after 11 and 18 min, respectively. This shows that the liquid entry pressure measurements in Figure 4, with a pressure step of 0.1 bar each 30 s are not representative for long-term membrane operation in membrane distillation. The differences between the MD process and the liquid entry pressure tests might explain this behavior. A few wetted pores are only detected after sufficient time in the liquid entry measurement, while in MD an immediate increase of the permeate conductivity  
Figure 4: Liquid entry pressure at different SDS concentrations, [NaCl] = 35 g/L.  
Figure 3: Contact angle measurements at different SDS concentrations, [NaCl] = 35 g/L.  
is observed. In this respect, membrane distillation is much more sensitive in detection of leakages. The prediction of membrane wetting based on liquid entry pressure using this procedure might therefore be an underestimation and it is recommended that the time dependence must carefully be considered when evaluating the wetting behavior of a membrane.
## 3 System Model
### Implementation
#### 3.4.1 UE-Cell Center Distance and Elevation Angle Prediction Model Considering Propagation Delay  
To train the model, the data generated and preprocessed in Section 3.3.3 was used. The XGBOOST algorithm was used and regression values were predicted using XGBRegressor, and MultiOutputRegressor was used to predict multiple features. To improve the performance of the model, Bayesian optimization, which can efficiently find hyperparameters, was used. In Bayesian optimization, gamma, learning rate, max depth, estimator, and subsample were used as parameters for XGBOOST hyperparameter tuning. Each range used is shown in Table 13.  
In order to compare the performance of the hyperparameter range, cross validation was performed three times using cross validation. In order to find the interval that maximizes the performance, the target of the object function was used as an indicator of neg mean squared error.  
Figure 11: Sampling datasets.
## 5 Discussion
### Paleo-Redox Conditions  
The oxidation-reduction sensitive trace elements are those trace elements whose solubility is significantly controlled by the redox state of the sedimentary environment, leading to their migration and self-enrichment in reducing water bodies and sediments [28]. The enrichment and accumulation of elements such as Ni, U, Th, and Cr in sediments can reflect the redox environment at that time [29]. Therefore, this study employs several trace element ratios including U/Th, V/Cr, and V/(V + Ni) to determine the paleo-redox conditions.  
Typically, a U/Th ratio <0.75 indicates oxidizing conditions, a ratio ranging from 0.75 to 0.15 indicates oxygen-poor conditions, and a ratio >1.25 indicates anoxic-sulfidic conditions [30; 31]. The ratios of V/Cr and V/(V + Ni) can also serve as indicators of paleo-redox conditions, where a V/Cr ratio <2 indicates oxidizing conditions, a ratio ranging from 2 to 4.25 suggests oxygen-poor conditions, and a ratio >4.25 indicates weakly oxidizing-reducing conditions. When V/(V + Ni) ranges from 0.46 to 0.6, it indicates oxygen-poor conditions, a ratio ranging from 0.6 to 0.84 suggests oxygen-depleted conditions, and a ratio >0.84 indicates sulfidic conditions.  
According to the geochemical indicator diagrams of oxidation-reduction in the Qiongzhusi formation in the southern Sichuan Basin (Figures 9 and 10), during the deposition of the Qiongzhusi 1-1 submember, the water body was relatively deep, primarily situated in an anoxic and sulfidic environment within the deep water continental shelf. As the depth of the sedimentary water body decreased, the overlying Qiongzhusi 1-2 submember and Qiongzhusi 2 member gradually transitioned from anoxic and sulfidic conditions to anoxic and weakly oxidizing conditions. A comprehensive analysis of the stratigraphic distribution trends of elements and various indicators indicates an early sulfidation enhancement in the Qiongzhusi 1 member, followed by a general weakening of sulfidic conditions until suboxic and sulfidic conditions prevailed. In general, the Qiongzhusi 1-2 submember of the lower part of the Qiongzhusi formation in the southern Sichuan region was under an anoxic and sulfidic environment, with the water body gradually oxidizing upwards, and by the Qiongzhusi 2 Member, it was in a suboxic and weakly oxidizing environment.  
Figure 8: Sr/Ba vs. Zr/Al binary diagram of the ancient water depth of the Qiongzhusi formation in the southern Sichuan Basin.