esa-sceva/satcom-chunk-collection huggingface dataset:
# An Accelerated Maximum Flow Algorithm with Prediction Enhancement in Dynamic LEO Networks
## 4 Predictive Acceleration Algorithm for e-TEG Satellite Networks
### Sdsn  
Incorporating predictive acceleration into e-TEG networks improves computational efficiency, but real-time network adaptation remains a challenge. To address this, we leverage the SDSN framework, which enhances network programmability and flexibility.  
SDSN [38] is a transformative approach in satellite communication networks, leveraging SDN principles to separate data and control planes. This minimizes hardware demands and focuses resources on data transmission, while control plane satellites enable real-time network status updates for efficient policy deployment and resource scheduling.  
We implement a satellite routing algorithm within the SDSN framework to enable dynamic flow control and intelligent network adaptation. In the SDSN framework, we have the management plane based at the ground center, which computes the global routing paths and predicts flow based on real-time information from the LEO satellites and GEO satellites. GEO satellites, as network controllers, provide global oversight, compiling a comprehensive view of the LEO network and enabling real-time updates to routing paths. The data plane comprises LEO satellites and ISLs, responsible for packet forwarding based on programmed forwarding tables provided by the management plane. By implementing the proposed algorithms within the SDSN framework, LEO satellites follow the optimized paths computed by the predictive acceleration algorithm, reducing computational overhead and ensuring that flow optimization is dynamically adapted to real-time network changes.
# Floor Heave Mechanism and Anti-Slide Piles Control Technology in Deep and Large-Span Chamber
## 6 Conclusions  
Deformation and failure mechanism of floor heave in the deep large-span chamber were discussed by means of plastic limit analysis theory. A model test based on two-dimensional digital speckle correlation method confirmed the reliability of the theoretical analysis. On this basis, we proposed anti-slide pile controlling of floor heave in the same situation and derived the supporting parameters of the anti-slide pile (including length and anti-sliding ability). Based on the application of the anti-slide pile in the gangue winch room of Huafeng Coal Mine, the following conclusions were obtained:  
Under the action of the compression mold effect, the local shear failure first appears below the loading area and develops to the middle part gradually; when the load increases to a certain extent, the local shear failure develops to form a continuous sliding surface and continuous plastic flow deformation occurs.  
The essential mechanism of the anti-slide pile controlling of floor heave is that the floor enters into plastic flow in the form of shear slip under stress from vertical load. Laying anti-slide piles perpendicular to the slip surface through the floor can resist shear deformation and realize the goal of stability.  
For anti-slide piles, controlling floor heave was proposed according to plastic limit theory; the limit analysis of slip line theory provided a theoretical basis for the design and parameter determination of the anti-slide pile.  
An example showed the scheme combining anti-slide piles with anchors has strong supporting capacity to control floor heave in deep chambers, which can meet the needs of using the floor under the limit equilibrium state. The combination is beneficial to ensuring the uniform stress of the floor in large-span chambers and maintaining the floor in good condition.  
Practice proved that controlling floor heave by anti-slide piles provides the advantages of a simple process, fast construction, low cost, and significant effects, which have values for their popularization and application in similar conditions.
# Elderly Fall Detection in Complex Environment Based on Improved YOLOv5s and LSTM
## 4 Fall Detection with WiFi Signal Based on LSTM Model
### Fall Prediction Principle Based on WiFi Signal  
This study explores a fall detection method through WiFi signals under an occluded relationship, mainly through CSI amplitude data. Generally, WiFi signal data are first collected and CSI amplitude data are extracted, and then the mapping relationship between amplitude and human posture (fall, standing or sitting) is established to complete the fall detection task. When the environment is in a static state, that is, there is no human activity, the channel is less affected and the CSI amplitude is relatively stable. However, when there is action in the environment, the CSI signal is disturbed due to the interference of human body action on the channel, and the change in amplitude increases sharply. Based on these characteristics, a change in the current CSI amplitude can form the basis of whether there is a change in human posture in the environment. The overall WiFi-based fall detection method is as follows: First, it determines the change threshold of CSI amplitude used to judge whether there is activity and takes this threshold as the benchmark. When the CSI amplitude change exceeds this threshold, the human body posture is considered to have changed, and the appropriate activity interception algorithm is used to intercept the active fragments in the window; then, valid activity fragments are extracted and invalid activity fragments are eliminated by a valid activity fragment screening algorithm. Finally, the trained fall detection model estimates the valid activity fragments.
# An Overview of the Applications of Earth Observation Satellite Data: Impacts and Future Trends
## 3 Results
### Statistical Characteristics
Each mission is based on a constellation of two satellites to shorten the revisit cycle and expand coverage. Sentinel missions have considerable advantages over older EO missions (such as the European Remote Sensing Satellite (ERS) and Envisat missions) due to the short revisit cycle and relatively high spatial resolution of the data [77]. Sentinel-2 is considered to be the most suitable current satellite mission for vegetation monitoring, and the fusion of Sentinel-1 and 2 data has great potential for the management of natural disasters [78].
# A Simulator for Investigation of Breakdown Characteristics of SiC MOSFETs
## 3 Results and Discussion
### Evaluation of the Doping Profile  
In addition to investigating the impact of the corner curvature structure, we also assess the influence of the doping profile on BV. We further evaluate the variation in Baliga's Figure-of-Merit (BFoM) [36] with the doping profile, which is a valuable factor in comparing the performance of power MOSFETs; it can be expressed as follows [36]:  
\[\text{BFoM}=\frac{4\text{BV}^{2}}{R_{on}} \tag{8}\]  
Figure 10 plots the BV and BFoM dependence on the doping concentration of the drift region (N\({}_{\text{Drift}}\)). There is a pronounced decrease in BV as the doping concentration of the drift region increases, as shown in Figure 10a. In Figure 10b, the BFoM initially decreases with the increasing dopant concentration, but changes very little as the dopant concentration exceeds \(10^{16}\) cm\({}^{-3}\). This is because the depletion region area reduces with the increasing doping concentration, which provides a wider current flow path. Therefore, the doping concentration in the N drift region should be as low as possible in order to achieve better device performance.  
Moreover, Figure 11 shows a significant reduction in BV when a Gaussian doping profile is incorporated between the drift region and the substrate. This observation highlights the substantial influence of increasing the dopant concentration in the N+ drift region, which leads to a reduction in the depletion region and thereby affects the breakdown characteristics.  
Figure 11: BV versus the depth of the Gaussian doping profile.  
Figure 10: The relationship of (**a**) BV and (**b**) BFoM with the doping profile of the drift region.
# Green Hydrogen Storage in an Underground Cavern: A Case Study in Salt Diapir of Spain
## 3 Methodology and Results
### Operational Parameters
#### 3.2.4 Density of Hydrogen Storage  
Hydrogen at high pressures no longer behaves as an ideal gas, and a compressibility factor must be used in the equation of state. This factor depends on temperature and pressure (real gas equation of state). The maximum and minimum densities are obtained [26] for the average temperature calculated in the cavern and the maximum and minimum pressures that the gas will have according to its tensional state (Equations (8) and (9)).  
\[\mathrm{\rho}_{\mathrm{H_{2},\;max}}=\frac{\mathrm{P}_{\mathrm{max}}\times \mathrm{M}}{\mathrm{Z}_{1}\times\mathrm{R}_{0}\times\mathrm{T}} \tag{8}\]  
\[\mathrm{\rho}_{\mathrm{H_{2},\;min}}=\frac{\mathrm{P}_{\mathrm{min}}\times \mathrm{M}}{\mathrm{Z}_{2}\times\mathrm{R}_{0}\times\mathrm{T}} \tag{9}\]  
The molecular mass of hydrogen is 2.016 g/mol and the gas constant is 8.314 J/K\(\cdot\)mol. The compressibility factors are calculated with Table 1 or through a program [27], thereby obtaining values of Z1 and Z2 of 1.09447 and 1.03525, respectively, from the temperature and the maximum and minimum pressure.  
The value obtained for the maximum density is 11.4 kg/m\({}^{3}\) and that for the minimum density is 4.51 kg/m\({}^{3}\).
# Survey on Unmanned Aerial Vehicle for Mars Exploration: Deployment Use Case
### Motivation and Contribution  
Progress in recent technologies has enabled UAVs to be considered valuable platforms for planetary exploration [6]. UAVs have had extremely high progress to be applied for space missions [7]. However, the applied methods for planetary exploration have limited mobility and low resolution and provide limited information about the planet. We have been motivated to use UAVs for space exploration to resolve these issues. In other words, we can say that UAVs can overcome the planetary measurement gap. Exploiting space through UAVs will have many benefits. UAVs can provide real-time services at the edge of the network [8]. UAVs can map a large area of the planetary body and gather data from smart environments [9]. Moreover, they have better resolution compared to the satellites and orbiters used till now. Since UAVs are remote-controlled spacecraft, they can have sufficient station time [10]. The contribution of this paper focuses on the complete comprehensive survey and previous failures in space exploration. Furthermore, we provide a cost-effective solution [11] by deploying UAVs in space. The main aim of our research work is to simulate a UAV model for successful deployment on Mars. The UAV model proposed in our study is utilised to distinguish between flight conditions on Mars' surface and those on Earth. It supports acrobatic maneuvers, including forwarding looping, backward looping, left barrel rolls, and right barrel rolls, giving enhanced coverage and better resolution.  
The remaining sections of the paper are as follows: Section 2 regards the related work and the types of UAVs for space investigation. Section 3 discusses the preliminary studies, failed missions, and the types of UAVs used previously for planetary exploration (particularly Mars, Venus, and Titan). Section 4 presents the simulation results and discussion, including the system model for deploying a UAV prototype on Mars' surface, parameters considered for the successful Mars flight, and the simulated results achieved. Section 5 investigates the opportunities, future scope, and challenges for deploying UAVs on Mars. Finally, the paper is concluded in Section 6. Further, the list of the abbreviations has also been tabulated in Abbreviations section that is used throughout this article.
# On-Orbit Absolute Radiometric Calibration and Validation of ZY3-02 Satellite Multispectral Sensor
## 2 Materials
### Calibration Site and Targets
#### 2.3.3 The Calibration Tarps  
In order to properly calibrate the ZY3-02 MUX, a set of four radiometric calibration tarps with nominal reflectance of 5%, 20%, 40%, and 60% (with relatively stable reflectance curve around the nominal values with an error of less than 3%) was designed and deployed to the Baotou site. These four radiometric calibration tarps were designed as ideal calibration targets with good Lambertian properties measured and validated at the laboratory, which should be relatively flat with little variation (less than 7% of the nominal values) in the surface feature and be stable in a spectral sense. Two color-scaled radiometric tarps of blue and red were also designed with quasi-Lambertian properties for on-orbit absolute radiometric evaluation. Each of these calibration tarps covers an area of 60 m \(\times\) 60 m. The spatial variation of each calibration tarp is less than 2%. The laboratory measured bi-directional reflectance factor (BRF) of the calibration tarp shows that the spectral varia  
Figure 2: The RadCalNet Baotou site.  
tion of the four radiometric calibration tarps' reflectance over 400-1000 nm is less than 3%. Figure 4 shows the arrangement of the calibration tarp at the Baotou site during the ZY3-02 calibration campaign.
# Ultrawideband Cross-Polarization Converter Using Anisotropic Reflective Metasurface
## 6 Oblique Incidence Waves Performance Analysis  
Polarization conversion can be easily achieved through anisotropic structures in reflection mode, but these structures are susceptible to oblique incidence angles. The efficiency of a polarization conversion metasurface can be studied with a wide range of incident angles to forecast its stability and performance. The suggested metasurface polarization conversion performance for oblique incidence must be investigated, as shown in Figure 6. At normal incident waves, the operating bandwidth of the proposed structure is 13 GHz (13 GHz to 26 GHz); as we increase the incident angle, it slightly affects the bandwidth. Considering \(\theta=10^{\circ}\), the structure is relatively stable for the operating bandwidth. At \(\theta=20^{\circ}\) and \(30^{\circ}\), the higher frequency band slightly decreases to 23 GHz and 22.5 GHz, respectively (Figure 6b). For the remaining operational frequencies, the performance is relatively stable. It is ensured that the specified metasurface operates effectively in a large operating band throughout a wide range of incidence angles. Even when the incidence angle reaches \(30^{\circ}\), it can operate over the frequency range of 13-22.5 GHz, with a _PCR_ of more than 80%. As a result, the proposed metasurface is effective across a broad range of incidence angles.  
Figure 5: Surface current distribution of the proposed anisotropic reflective metasurface at the top and bottom metallic layers at various resonant frequencies. (**a,b**) 13.8 GHz, (**c,d**) 19.7 GHz.
## 3 Research Design
### OTT Consumer Classification with Imbalanced Data
Upon completion of cost-setting, classification is performed to determine the class to which samples belong. When a sample is given, the probability of indicating the class to which it belongs is calculated. Supposing that \(E\) is the entire dataset. Then, \(E_{i}\) is a resample of \(E\) with \(n\) examples. The probability that an example, \(x\), belongs to a class, \(j\), is as follows [54]:  
\[P(j|x)=\frac{1}{\sum_{i}1}\sum_{i}P(j|x,\ M_{i}), \tag{1}\]  
where \(i\) ranges from \(1\) to \(m\), and \(m\) is the number of newly produced resamples. Then, \(M_{i}\) is a model created by applying a classification learning algorithm to \(E_{i}\). Here, the risk occurring when \(x\) is classified as a class \(s\) can be defined as follows [15]:  
\[R(s|x)=\sum_{j}P(j|x)C(s,\ j). \tag{2}\]  
We must minimize the risk of sample assignment. Therefore, class \(s\), which satisfies Equation (3), becomes the class to which \(x\) is assigned:  
\[\operatorname{argmin}_{s}R(s|x). \tag{3}\]  
For OTT user classification, because there are three classes, the variables, \(s\) and \(j\), indicate the degrees of freedom for high, medium, and low classes. Various ML algorithms can be used to generate a model, \(M_{i}\), which is used for probability calculation when performing consumer classifications. In this study, we use common ML methods, including decision tree, SVM, and KNN, because we need to determine whether the performance can increase in an imbalanced data environment when our framework is applied. This allows us to check whether data encountered in real-world \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Actual High** & **Actual Medium** & **Actual Low** \\ \hline Predicted High & \(C(h,\ h)\) & \(C(m,\ h)\) & \(C(l,\ h)\) \\ Predicted Medium & \(C(h,m)\) & \(C(m,m)\) & \(C(l,m)\) \\ Predicted Low & \(C(h,l)\) & \(C(m,l)\) & \(C(l,l)\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Asymmetric misclassification cost matrix. situations can be accurately classified, regardless of which ML algorithm is used. The ML algorithms used in this study are presented in Section 4.2.
# Review of Photogrammetric and Lidar Applications of UAV
## 6 Discussion
### Discussion on Applications of UAVs
#### 6.2.5 Non-Surveying Applications
UAVs are also suitable for land mine clearance when they use hyperspectral imaging technology to quickly identify landmines buried in the ground. With the expansion of UAV technology, their misuse for illegal activities such as jamming, information leakage, or espionage is increasingly occurring. UAVs are also directly used in military operations, where they can be damaged or destroyed; therefore, we recommend using the cheapest possible camera sensor for these purposes. UAVs are also used to inspect power lines and pipelines [198; 199; 200; 201; 202; 203]. The article [198] used a DJI Phantom 4 PRO V2.0 UAV to detect abnormal vibration of dampers on portablepower lines. During flight, a distance of 10 m from power lines and transmission towers was maintained. In the article [199], the authors discussed the application of UAV technology to inspect power lines that were imaged at a low height. A 16.5 km long section was selected for this research in Yichang, China. A fixed-wing UAV with a Nikon D810 digital camera was used to acquire images. In total, 1066 images were acquired, with a GSD accuracy of 3.5 cm. The authors in the article [200] described a new sensor package designed for micro- or mini-UAVs. This package can include a laser scanner, camera, IMU, and other sensors that can vary according to the requirement and application. Hokuyo (30 LX) and Sick LD-MRS-400001 on the md4-1000 UAV were also investigated. The authors of [201] dealt with the design of a safe flight approach (SFA) of UAVs in controlling power lines. The authors of the article [202] discussed the development of a platform that provides control of UAVs when inspecting overhead transmission lines. This platform has already been applied in Tianjin, China, where it achieved excellent results. The article [203] proposes a complementary attitude data system based on augmented reality tags (AR Tags) to enhance the reliability of the UAV flight-attitude-determination system, making the results positive. The positional accuracy of the UAV was increased. The results of these studies confirm that UAV lidar technology can locate obstacles in the power line corridor with high accuracy (\(\pm\)0.5 m). The testing of this UAV confirmed its effectiveness in the inspection of electrical lines and the very control of the distribution of electrical lines to ensure the safety of operation. UAV technology is currently used in everyday life in almost every scientific, technical, and non-technical discipline. UAVs have revolutionized every industry and are also used in a wide range of applications for civil, commercial, and military purposes.
## 1 Introduction
In all models of relative permeability hysteresis, the scanning curves are very important. As shown in Figure 2, assuming the minimum water saturation is \(S_{wc}\) and water injection begins, then \(k_{n}\) should follow the imbibition curve until the water saturation reaches its maximum value \(S_{w}^{max}\). If, after reaching the maximum value \(S_{w}^{max}\), drainage begins, \(k_{n}\) will follow the drainage curve until \(S_{w}=S_{wc}\). If the drainage process is interrupted before reaching \(S_{wc}\) and water injection starts again, \(k_{n}\) now needs to stop following the drainage curve and instead follow the imbibition curve. However, the imbibition and drainage curves almost never intersect at any point, so to make the transition from one point to another smooth, we need a transitional curve that starts from that point to another relative permeability curve. These transitional curves are called scanning curves [17; 18]. Similarly, during the imbibition process, a transition can be made to the drainage process from any point, generally the drainage curve and imbibition curve, also called boundary curves or relative permeability envelopes. Research on the hysteresis effect of relative permeability has led to the development of various two-phase and three-phase models. Traditional studies on relative permeability hysteresis models generally rely on experimental results to establish the models. With the advancement of CT scanning technology, a novel method for studying relative permeability hysteresis models has emerged in recent years. This method establishes digital rock core models based on CT scanning, and uses geometric and calculus approaches to create models that enable forward calculations of relative permeability to describe the hysteresis phenomenon. The discussion on relative permeability hysteresis will be divided into three parts: Mathematical Models, Experimental Studies, and Applications. These three Sections will together provide a comprehensive perspective on a deep understanding of the relative permeability hysteresis phenomenon, from the establishment and optimization of theoretical models, to the design and execution of experimental methods, to the practical applications and impact of these models and experimental results in the development of oil and gas fields.