esa-sceva/satcom-chunk-collection huggingface dataset:
###### Abstract  
Insulators on overhead power lines have long been exposed to the outdoors and are susceptible to pollution and salt contamination. Due to factors such as wind and gravity, pollution in the atmosphere gradually deposits on the surface of the insulator. In humid and windy conditions, conductive pollutants begin to dissolve in the water on the surface of the insulator, increasing the leakage current and affecting insulation performance. This study mainly uses a data acquisition system to measure the leakage current of the insulator and weather parameters (including temperature, relative humidity, pressure, wind speed, and ultraviolet) around the insulator. Artificial intelligence is then applied to establish a prediction model for leakage current based on weather parameters. The established model accurately predicts insulator leakage current through weather parameters. In order to observe the real-time status of the insulator, this study establishes a monitoring platform that integrates the predicted leakage current with weather parameters. It allows users or maintenance personnel to connect to the server through the network to observe the predicted results and weather parameters. The results can establish a real-time salt contamination monitoring system for insulators on transmission lines, enabling operation and maintenance personnel to understand the actual insulation situation of the insulator in real-time. This can not only prevent power outages due to salt contamination or pollution but also reduce the workload for maintenance personnel. Moreover, the maintenance strategy is upgraded from time-base maintenance to condition-base maintenance, significantly improving the efficiency of operation and maintenance for power lines.  
insulators; machine learning; leakage current; salt contamination; artificial intelligence; condition-base maintenance
# Ultra-High-Performance Concrete (UHPC) Piles and Splicing Options
## 4 UHPC Pile Splices
### Other PPCP Cycles Applicable to UHPC Piles
#### 4.2.2 Epoxy-Bonded Dowel Splices  
Epoxy-bonded dowel splices are created by casting or drilling holes in the top of the lower pile to receive dowel rebars protruding out of the lower end of the upper pile. Dowel bars can be made of carbon steel, stainless steel (SS), carbon fiber-reinforced polymer (CFRP), or glass fiber-reinforced polymer (GFRP). The dowel rebars must have adequate length to bond with the other pile segment. Different types of resin and cementitious grouts can be used as filler and bonding agents to connect the pile segments [52; 53].  
Corrosion-resistant dowel bars are often chosen as they can increase the durability of pile splices [54]. One drawback of this splice type is that the epoxy must be cured before driving of the spliced pile can resume to ensure that the pile splice has sufficient tensile strength. This can be overcome by placing a cushion between the pile segments and continuing to drive while the epoxy is still wet [14]. Also, the in-place flexural strength of the pile splices is limited for this option, especially in an unplanned situation. An example of an epoxy dowel pile splice is shown in Figure 14[53].  
This method is commonly used for splicing in the field and requires low material and labor. Epoxy-bonded dowel splices are the most common splicing technique used in the state of Florida [14].
## 5 Conclusions  
In this study, the influence of different pre-treatments and coatings on the mechanical behavior of an adhesive joint between glass and timber is investigated in order to identify an appropriate technique for including adhesive junctions in the industrial production of building components such as windows, glazing panels for curtain walls, etc. In addition, an FE model was developed and verified through an experimental--numerical comparison of the results.  
The results highlight that  
1. The pre-treatments on the glass and/or timber side of the bonded joint reduce the maximum displacement, shear stress, and shear strain. They may also contribute to increase the maximum failure load of the joint, but this behavior is not observed for all the tested series; in particular, adhesion promoters (111 and 94) seem to have a better effect than a moisture inhibitor (Silane) in this respect. As a consequence of the decrease in the ultimate displacement, all pre-treated series have higher stiffness than the untreated ones. These treatments, in fact, improve surface adhesion at the adherend--adhesive interface, which in turn enhances load transmission between the adherents up to the maximum permissible stress of the glass, before the adhesive failure (AF) occurs. This aspect of stiffness is relevant according to the different fields of application (i.e., depending on the displacements that the joint can bear, a combination is more or less suitable for a specific purpose).
2. The behavior of the painted joint strongly depends on the type of paint used on the glass: a paint of the same nature of the adhesive (i.e., epoxy paint) can increase the ultimate load but has no significant effect on the remaining considered parameters (as summarized in Table 8), nor on the type of failure mechanisms. Conversely, the use of an acrylic paint causes a worsening of the overall mechanical behavior and shifts the collapse mode from glass failure to interface failure.
3. According to the results of the numerical modeling, it can be concluded that the simulation appears to be more representative of all those series where adhesive promoters are used. This aspect can be attributed to the fact that the usage of adhesive promoters reduces the effects on the joint structural behavior of the uncertainties affecting all specimens because of the manufacturing process, which cannot be easily included in the modeling.  
Conceptualization, P.M.; methodology, P.M., R.A., F.M., A.D.L. and R.S.; software, A.D.L.; validation, R.A. and A.D.L.; formal analysis, R.A. and A.D.L.; investigation, R.A., A.D.L. and R.S.; resources, P.M., F.C. and R.S.; data curation, R.A., F.M. and A.D.L.; writing--original draft preparation, R.A. and A.D.L.; writing--review and editing, R.A., A.D.L. and R.S.; visualization, R.A.; supervision, P.M., F.C. and R.S.; project administration, R.A. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The data supporting the findings of this study are available upon request.  
The authors declare no conflicts of interest.
# Real-Time 3D Reconstruction Pipeline for Room-Scale, Immersive, Medical Teleconsultation
## 5 Topology and Silhouette-Preserving Simplification
### Silhouette Preservation  
Vertex-clustering-based simplification is not designed to preserve the topology, and the QEF error is only correct in a valid 2-manifold. Geometry captured from depth images is highly nonmanifold since many objects will only be seen from one side. If simplification via vertex clustering is applied trivially on nonmanifold edges and corners, they will be pulled in, significantly changing the perceived silhouette in rendering (Figure 13).  
To address this issue, each point is classified as interior or exterior to detect which octree nodes must be excluded from simplification. We query the entire 26-point neighborhood for each leaf cell in parallel in a GPU kernel and detect all potentially generated incident faces. To simplify this query, we use the approximation that four incident faces per vertex indicate that the vertex is placed in the mesh interior in a quad face, which is invalid, and exceptions exist (Figure 14a). Furthermore, if three faces are located in the same \(2\times 2\times 2\) octant of the neighborhood, the face is also in the interior (Figure 14b). All permutations of three incident faces are covered with two conditions: if less than three nodes are empty in the neighborhood described in Figure 14b, the node is an interior node.  
Figure 12: Conditions for Simplification. Visualization of the simplification conditions to prevent the generation of internal faces. When red child nodes are empty, the neighboring blue nodes must also be empty. In (**a**), the neighbor node only shares a single corner, (**b**) is one of three external neighbors with a shared edge that requires an additional empty internal node in red, and (**c**) is one of three neighbors with a shared face. In total, queries for up to seven external neighbors must be performed in the worst case.
## 2 Materials and Methods  
The approach pursued aimed at the accurate classification of a specific tree crop within a complex vegetated landscape. The fundamental idea is to interpret landscape elements to understand which spectral signatures might lead to misclassifications. To enhance classification precision, we adopted a hierarchical framework designed to isolate distinct land cover components through carefully optimized steps. Leveraging data from two different satellite platforms and utilizing all available spectral bands, we implemented a comprehensive approach. To effectively capture the variability of the crop, we employ a 3-year median-based approach for optical bands and solely the latest year's averages for radar variables. This methodology enables a reliable classification of the specific perennial crop on a regional scale, effectively mitigating random variability across different fields and years while preventing overestimation of the crop area in zones where the crop has recently been removed.  
Sentinel data have been exploited. In particular, the Sentinel-1 Level-1 Ground Range Detected (GRD) data can allow to assess land use, monitor seasonal changes, and identify soil degradation [54]. Sentinel-2 provides image data with 13 different spectral bands, ranging from the Visible (VNIR) and Near Infra-Red (NIR) to the Short-Wave Infra-Red (SWIR).  
Overall, the availability of such a kind of data is very important nowadays for diachronic change detection studies, such as those aiming at generating maps for agricultural areas and other key landscape features [55; 56].
# Sequential Convex Programming for Nonlinear Optimal Control in UAV Trajectory Planning
## 3 Problem Formulation
### Equality Constraints  
To begin the algorithm, it is necessary to select the initial velocity and the position parameters. Furthermore, they must decelerate when they near their individual goals until they reach complete rest. Therefore, their final velocities and accelerations must also be zero. Equations (6) and (7) can be utilized to enforce the constraints on initial velocity and position. Equality constraints can enforce final acceleration, velocity, and position constraints. Considering that the constraints apply to each axis for final acceleration, velocity, and position, there must be nine equality constraints in total for every agent. Therefore, it is necessary to have a total of 9N boundary constraints in the system. These constraints can be expressed as equality constraints in the following manner:  
Final velocity constraint: \(v_{i}^{t}=\mathbf{0}_{3\times 1}\)  
Final acceleration constraint: \(a_{i}^{t}=\mathbf{0}_{3\times 1}\)  
Final position constraint: the final positions in the form of \(\mathbf{x}_{i}\). For a single agent '\(i\)', we have the following:  
\[p_{i}^{t}=\mathbf{X}_{f,i} \tag{21}\]  
The matrix representation of these constraints can be written as follows:  
\[A_{eq,fp,i}X_{i}=b_{eq,fp,i} \tag{22}\]  
After establishing the equality constraint matrices for a single agent, our next step was to combine these constraints into a unified matrix. The equality constraints for a single vehicle, '\(i\)', can be stacked on top of each other, resulting in a matrix representation of the equality constraints as follows:  
\[A_{eq,i}X_{i}=b_{eq,i} \tag{23}\]  
We have now created the matrices representing the equality constraints for a single vehicle. We generalized this concept to encompass the matrices that express all the equality constraints for all the agents.  
\[A_{eq}X=b_{eq} \tag{24}\]  
where \(A_{eq}\in\mathbb{R}^{9N\times 3N(T+1)}\) and \(b_{eq}\in\mathbb{R}^{9N}\).
# THz Rectennas and Their Design Rules
## 4 Theory of Operation
### Hybrid Diodes  
The reason we name them hybrid is because they have both features of geometric devices with large MFPL and junction diodes where a voltage drop is present at the junction between the graphene layer and the doped semiconductor substrate. They have earned recent interest based on their features [PERSON] (2017). The thermionic emission in conjunction with the Schottky-Mott model gives a surprisingly good description of their electrical properties as stated by [PERSON], et al. [PERSON] et al. (2017).  
[PERSON] and [PERSON] have recently modeled this device and obtained efficiencies in excess of 58% at 897 GHz for a graphene antenna on an n-doped GaAs substrate [PERSON] et al. (2017). The Schottky-Mott model equation used in their study is (20).  
\[I(T,V)=A_{sub}^{gr}\cdot A^{*}\cdot T^{2}\cdot exp\left(-\frac{e\phi_{SBH}}{k_ {B}T}\right)\cdot\left[exp\left(\frac{eV}{\eta k_{B}T}\right)-1\right], \tag{20}\]  
where \(I(T,V)\) is the current response of the device with respect to voltage and temperature, \(A_{sub}^{gr}\) is the contact surface area between the graphene and the substrate, \(A^{*}\) is the Richardson constant, \(T\) is the temperature in Kelvin, \(\phi_{SBH}\) is the Schottky barrier potential height, \(V\) is the applied voltage value, \(\eta\) is the ideality factor and \(k_{B}\) is the Boltzmann constant.  
Although the tried frequency is below the THz band, the modeling for this device results in exceptional efficiencies compared to all the experiments reviewed in this paper. The structure, also, benefits from the small capacitance of the graphene-substrate junction. However, no measured data are provided for this model to compare to in the THz band. It is also expected to obtain different responses at higher frequencies due to the increasing impact on the wave/Dirac function waveforms. Figure 9 shows the response of the modeled hybrid device compared to another MIM diode response. It shows that the response for the hybrid device is many orders of magnitude higher for lower available power levels.
# Theoretical Study of Large Uncoupling Coefficient Loading for Surface Blasting
## 2 Classical Theory of Uncoupled Charge Smooth Blasting  
### Impact Pressure on the Blast Hole Wall with a Radially Uncoupled Continuous Charge  
In the case of uncoupled charges, the blast wave first compresses the air present in the gap, producing an air shock wave. This air shock wave impacts the blast hole wall. The following assumptions are considered for the study:  
(1) Absence of air in the interstices;  
(2) Blast products are generated in the gap, which follows the law of \(PV_{n}\) = constant (\(n\) = 3), where \(P\) is pressure and \(V\) is volume.  
(3) The initial pressure at expansion is calculated as the average impact pressure.  
Based to the above assumptions, the initial pressure acting on the blast hole wall is calculated as follows:  
The average impact pressure \(P_{c}\) of the explosion products is expressed as  
\[P_{c}=\frac{1}{2}P_{1}=\frac{\rho_{0}{D_{1}}^{2}}{8} \tag{1}\]  
where \(\rho_{0}\) is blast product density, and \(D_{1}\) is blasting velocity.  
The pressure before the by-products of the explosion hits the wall of the shell, i.e., the incident pressure \(P_{f}\) is  
\[P_{f}=P_{c}(\frac{V_{c}}{V_{b}})^{3}=\frac{\rho_{0}{D_{1}}^{2}}{8}(\frac{d_{c }}{d_{b}})^{6} \tag{2}\]  
According to the research of [PERSON] and [PERSON]\)[PERSON] ([PERSON] and [PERSON] [14]), the pressure amplifies by 8-11 times when the gaseous by-products impact the blast hole wall. Therefore, under the condition of an uncoupled charge, the impact pressure \(P_{2}\) acting on the blast hole wall is  
\[P_{2}=\frac{\rho_{0}{D_{1}}^{2}}{8}(\frac{d_{c}}{d_{b}})^{6}n \tag{3}\]  
where \(\rho_{0}\) is the density of explosives; \(D_{1}\) is the detonation velocity of the explosive; \(V_{c}\) is the volume of by-product gases before expansion; \(V_{b}\) is volume of the expanded blast by-products in the blast hole; \(d_{c}\) is charge diameter; \(d_{b}\) is blast hole diameter.
# Parametric Analysis of Control Techniques for 15 MW Semi-Submersible Floating Wind Turbine
## 3 Control Algorithms  
### Baseline Control  
In this study, the baseline controller consists of the classical PI control-based blade pitch controller and the generator torque controller. To avoid the resonance in the platform motions of the target FOWT, detuning techniques were applied [22]. Detuning can be achieved by selecting lower pitch and torque control frequencies than the platform's natural frequency. To achieve this, the linearization analysis and frequency response analysis were conducted using the OpenFAST linearization tool. Figure 5 shows the frequency response functions of the blade pitch control loop and the generator torque control loop with respect to the generator speed. The resonance modes of the target floating offshore wind turbine--such as those of the platform, tower, rotor, and blade--were dominantly observed in both control loops. For detuning, the control gain was selected such that the  
Figure 4: Comparison of the RAO results between experimental and simulation data.  
Figure 3: Comparison of the free decay test results between experimental and simulation data.  
magnitude of the frequency response crosses 0 dB at 0.1 rad/s, which is lower than the platform's natural frequency.  
Figure 6 shows the time-domain wind turbine simulation data without and with the detuning. It can be seen that the platform pitch motion, which was severe without detuning because the platform pitch mode is excited by blade pitching, is significantly mitigated when detuning is applied.
# Global Position Analysis during Official Elite Female Beach Volleyball Competition: A Pilot Study
## 2 Materials and Methods  
Six Defenders (age: 26.3 \(\pm\) 5.8 years; height: 175.3 \(\pm\) 5.5 cm; weight: 64.6 \(\pm\) 4.0 kg; training experience: 9.6 \(\pm\) 4.9 years) and six Blockers (age: 29.0 \(\pm\) 7.7 years; height: 178.0 \(\pm\) 5.2 cm; weight: 66.1 \(\pm\) 7.7 kg; training experience: 12.1 \(\pm\) 6.1 years) were studied. The top six female BV teams from the Portuguese National Beach Volleyball Championship (composed of 38 teams) took part. All the players competed at professional volleyball championships and had at least three years' experience of playing BV as professionals (10.9 \(\pm\) 5.5 years). All subjects were healthy, with no recent injuries, and had a physical examination and were cleared of any medical disorders that might limit their participation. Written informed consent, according to the Declaration of Helsinki, was obtained from players before the investigation, and the University of Tras-os-Montes and the Alto Douro Ethics Committee approved the study (REF.: Doc25-CE-UTAD-2016).  
Players were categorized by position (Blockers n = 6, Defenders n = 6), and data collection occurred over 30 official matches, with a total of 50 sets (16 first and second sets, 6 third sets, and 8 byes) during a tournament of the national championship. All the players were equipped with a commercially available 10 Hz GPS device containing an inertial measurement unit (Minimax S4, Catapult Sports, Melbourne, Australia), positioned in a harness between the C7 and T2 vertebrae. Each GPS was activated at least 10 min before matches began. Before testing, the GPS was activated and left for 10 min. This allowed the unit to download ephemeris data from satellites used to calculate location and distance, and data collection was monitored in real time. For data analysis, only data recorded during the match were considered (periods during time outs and intervals were not considered). The details of each positional variable can be seen in Table 1. Variables that express different levels of intensity (for example, displacement can be covered walking, jogging, or quick running) were expressed as the percentage of the total.  
The normality of the distribution of the variables was checked using the Shapiro-Wilk test. Values are reported as mean \(\pm\) SD. The Mann-Whitney test was used to compare each variable between positions (Defender vs. Blocker). The comparison be-tween sets was made between the first and second set, and between the second and fourth set, using the Wilcoxon test. Discriminant analysis with a 95% confidence in-terval (CI) was used to identify players' position variables; it was able to explain the differences between winners and losers using a coefficient greater than \(|\)SC\(|\)\(\geq\) 30 ([PERSON] and [PERSON], 2013). Effect size (ES) was calculated using Cohen's d ([PERSON], 2019). The analyses were performed using the SPSS 27.0 statistical software package (SPSS Inc., Chicago, IL, USA), with a significance level set at 5%.
## 7 Discussion  
The high level of agreement between the Fourier transforms derived from the experimental and numerical data provides an indication that the spectral signature of RI is caused by discrete vortices. Regarding the fact that the signature can be measured in a certain operating range before stall and not only in a brief moment during transient maneuvers, the special vortices rather belong to a whole prestall phenomenon than just being a feature of an inception process of rotating stall. The authors assume that the reversed clearance flow and associated blockage enables the formation of a Kelvin-Helmholtz-Instability (KHI). A corresponding flow model is shown in Figure 12. Once the interface between the reversed clearance flow (red) and the inflow (blue) extends circumferentially as a continuous shear layer, small disturbances appear as vortices. Even the entropy distribution upstream of the rotor in Figure 10 (bottom) resembles a typical wave-like pattern of a KHI. The basic physics behind the vortices is illustrated by the sketch in Figure 12 (mid/left). Accordingly, the vortex structures shown in green can be interpreted as a roller bearing, allowing the main flow to roll-off on the blockage region (dark grey). If a small perturbation emerges in the interface between the blockage and the inflow, it is being amplified and interacts with other perturbations while moving around the circumference. The resulting flow instability can therefore be regarded as an infinite 3D-KHI. At higher flow rates, when the trajectory of the clearance vortex is mainly deflected downstream, there is no continuous shear layer in which any small perturbation could grow to a prestall vortex (cf. Figure 12; mid/right). However, why is a compressor setup prone to such a remarkable prestall condition as RI? It is supposed that the reason can be found in a specific combination of blockage and critical rotor incidence (see Figure 12; top). As the mass flow is reduced, the trajectory of the clearance vortex moves in the upstream direction until a blockage of the entire tip region is excited. From then on, RI begins to develop in operating range \"B\", if the critical rotor incidence has not yet been reached in this flow regime. This assumption implies that forward spillage of the clearance flow and associated blockage does not necessarily lead to an inception process of rotating stall.  
Figure 11: Vortex dynamics (CFD).  
If the stalling incidence is reached before the entire rotor inlet is blocked by any secondary flow, compressor instabilities such as rotating stall can be triggered immediately by modes or spikes depending on the slope of the pressure rise characteristic: in this particular case, blockage and critical incidence coincide in one operating point. [PERSON] and [PERSON] (2014) [22] could even demonstrate that forward spillage of the clearance flow and associated blockage is rather a consequence of the spike initiation process and not the cause of it.