esa-sceva/satcom-chunk-collection huggingface dataset:
# Title-to-Length Coupling Analysis of an Off-Axis Optical Bench Design for NGGM
## 4 Global TTL Coupling
### Summary of the Global TTL Coupling  
To end this section, a summary is given on the cross talk between local and global TTL coupling in yaw and pitch degrees of freedom, respectively. The results are shown in Table 3. With a 2 mrad angular jitter, estimates on the margin on TTL coupling variation are given.  
Given the TTL coupling coefficients in the above table, together with the data for relative attitude variation between two satellites, the LRI ranging error may be obtained. From the GRACE Follow-on data, the attitude variation is at the level of mrad, and this generates a ranging error of approximately 20 nm. Further suppression of local TTL may reduce the noise budget of global TTL. More experimental work is needed to further assess the margin of errors for each source.  
Figure 19: Results of the rooftop mirrors misalignment simulation. Angular offsets of the rooftop mirrors, respectively of 2.5 \(\upmu\)rad and 5 \(\upmu\)rad, are considered in the simulation.  
\begin{table}
\begin{tabular}{p{56.9 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Main Sources** & **Degrees of Freedom** &
\begin{tabular}{p{113.8 pt}} **TTL Coupling Coefficients** \\ **Coefficients** \\ \end{tabular} & **Origin of TTL Noise** \\ \hline Optical components & Yaw & \textless{3} \(\upmu\)m/rad & The variation of the RP point and the coupling with the residual local TTL coupling \\  & pitch & \textless{1} \(\upmu\)m/rad & Additional LPS variation due to the offset between the pivot and the reflective point of the FSM. \\  & pitch & \textless{1} \(\upmu\)m/rad & The relative position of the FSM. \\ RP\&CoM offsety & Yaw & \textless{5} \(\upmu\)m/rad & Misalignment between RP and CoM in \(y\)-axis, offset is set to be 1 \(\upmu\)m. \\ RP\&CoM offsetz & pitch & \textless{3} \(\upmu\)m/rad & Misalignment between RP and CoM in \(z\)-axis, offset is set to be 1 \(\upmu\)m. \\ misalignment L1y misalignment L1z & yaw & \textless{3} \(\upmu\)m/rad & Misalignment of L1 in \(y\)-axis, offset is set to be 1 \(\upmu\)m. \\ misalignment L1z & pitch & \textless{2} \(\upmu\)m/rad & Misalignment of L1 in \(z\)-axis, offset is set to be 1 \(\upmu\)m. \\ M1\&M2 offset & Yaw & \textless{2.5} \(\upmu\)m/rad & Additional TTL coupling variation due to the misalignment of the \\  & pitch & \textless{1} \(\upmu\)m/rad & rooftop mirrors. Additional offset of 5 \(\upmu\)rad is introduced. \\ \hline \hline \end{tabular}
\end{table}
Table 3: Summary of the global TTL coupling in yaw and pitch degrees of freedom, respectively. Estimates on margin on TTL coupling variation are given.
# PS-CARA: Context-Aware Resource Allocation Scheme for Mobile Public Safety Networks
## 6 Simulation Results and Discussions
### Call Blocking Probability  
The proposed PS-CARA scheme also reduces the call blocking probability of the users as compared with the existing C-SRA scheme. The users call blocking probability decreases because of deploying a greater number of mPC in the public safety areas. This in turn reduces the traffic congestion which  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**MBS/Cell** & **mPC/MBS** & \multicolumn{3}{c}{**Average (50\%) Throughput (bits/Hz)**} & \multicolumn{3}{c}{**Edge (5\%) Throughput (bits/s/Hz)**} \\ \hline  & & **Total** & **MBS** & **mPC** & **mPC** & **mPC** & **BH** & **Total** & **MBS** & **mPC** & **mPC** & **BH** & **mPC** & **SH** \\ \hline
1 & 0 & 2.058 & 2.058 & 0 & 0 & 0 & 0.444 & 0.444 & 0 & 0 & 0 \\
1 & 4 & 2.251 & 2.049 & 5.283 & 3.354 & 3.857 & 0.447 & 0.442 & 1.263 & 0.847 & 1.160 \\
1 & 10 & 2.310 & 2.055 & 3.839 & 2.518 & 2.642 & 0.455 & 0.443 & 0.693 & 0.490 & 0.599 \\
1 & 20 & 2.270 & 2.058 & 2.9061 & 1.983 & 1.845 & 0.590 & 0.446 & 0.960 & 0.431 & 0.155 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Average and edge throughput comparison by adding mPC in conventional MBS.  
Figure 8: PS and non-PS users’ individual interference under the proposed PS-CARA scheme.  
occurs during the public safety scenario because a higher number of users access the limited spectrum of the MBS at the same time. We compare the simulation results in three different aspects: (1) using only C-SRA scheme where we randomly allocate the resources among users, (2) proposed PS-CARA scheme without giving priority to public safety users during resource allocation, (3) proposed PS-CARA scheme with public safety priority, where public safety users have been given high priority during resource allocation. The simulation results depicted in Figure 9 show that the proposed PS-CARA scheme with public safety priority outperforms all the other cases without giving priority. Hence, by giving priority to PS users the CBP reduces because the connection and resources are provided to users on a priority basis, which in turn results in less conestion for the priority users.
# Symmetric-Key-Based Security for Multicast Communication in Wireless Sensor Networks +
## 7 Conclusions  
In this paper, we proposed a highly efficient symmetric-key-based key management protocol for group-based communications in a distributed WSN with a cloud-based NMM. The protocol establishes confidentiality, integrity, and authentication for communication between an arbitrary group of motes in the network. In addition, the established group key is kept secret for the NMM.  
Two different approaches are described to share the group keys with all members. In the unicast approach, each member receives the key using a unicast message, whereas in the multicast approach, a combination of LI and a single multicast message is used to disseminate the group key to all members.  
Using simulations considering a different number of nodes in the group and a different number of hops from the publisher, we show that the multicast approach results in all situations in a significant smaller delay, compared to the unicast approach. When the number of nodes in the network is larger than three, less LL frames need to be sent over the network, resulting in better energy consumption behavior. The additional code size required for the multicast approach is negligible.  
Conceptualization, A.B. and M.C.; methodology, A.B., M.C. and K.S.; software, M.C.; validation, M.C., A.B. and K.S.; formal analysis, M.C.; writing--original draft preparation, M.C. and A.B.; writing--review and editing, M.C.; visualization, M.C.; funding acquisition, M.C.  
This research has been supported by the Agency for Innovation by Science and Technology in Flanders (IWT).  
**Conflicts of Interest:** The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{l l l} \hline \hline  & **Unicast** & **Multicast** \\ \hline
**ROM/flash** & 18,7057 bytes (36.5\%) & 18,9473 bytes (37.0\%) \\ \hline
**RAM** & 13,428 bytes (42.0\%) & 13,512 bytes (42.2\%) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Memory consumption (compared with available memory in the Zolertia RE-Mote platform) of an application using BMRF and the proposed protocol using the different approaches.
## 3 Results
### Trends in Vegetation and Response to Drought Trends in Vegetation and Response to Drought
Particularly, the correlation is most significant in August, with a correlation coefficient of 0.39. In contrast, the lag effect is not significant in September. This is because September is a critical period for the formation of yields of major grain crops in the Northeast. During this period, water and heat conditions are better matched, favoring crop growth and development, and are less affected by drought. After September, temperatures in the Northeast region drop significantly, and temperature becomes a dominant factor influencing the NDVI. As a result, the SPI in September showed the strongest correlation with the NDVI, with no significant lag effect. The response of vegetation to drought varies across different land use types due to differences in community structure, biodiversity, and water use patterns in vegetation ecosystems [70]. Overall, grassland correlates more strongly  
Figure 8: Correlation between SPI and different periods, such as current-month, one-month-lag, two-months-lag, and three-months-lag NDVI for different land use types in Northeast China. (**a**) Dry cropland, (**b**) woodland, (**c**) grassland, (**d**) wetland. with dry cropland, while woodland correlates less strongly with wetland. This indicates that grasslands and dry croplands are more sensitive to meteorological drought and more vulnerable to its impacts, while woodlands and wetlands are less affected [71]. Grasslands and dry croplands are primarily composed of shallow-rooted plants that can only obtain water from the surface. In contrast, woodlands have a deeper root system that allows them to access and consume more soil moisture, while wetlands are well watered [72; 73; 74; 75].
# Impact of HPC and Automated CFD Simulation Processes on Virtual Product Development--A Case Study
## 2 Materials and Methods
### Software and Hardware Stack  
Within the case study, all simulations were conducted with ANSYS Fluent v19.2. Besides the graphical user interface (GUI), ANSYS Fluent provides a scheme-based text interface (TUI) for automation of tasks. Scheme is a LISP dialect. For details, we refer the reader to [19, 20].  
We utilized the HPC system \"brtzx4\" with a total number of 91 compute nodes. Most nodes were equipped with two Intel Xeon E5-2630 v4 @ 2.2 GHz (Broadwell), resulting in a total of 20 physical CPU cores per node. We refer to those nodes as \"compute20\". Some of the nodes had additional memory (2x 128 GB RAM) and a GPU (NVIDIA Tesla P100, 12 GB), which we refer to as node type \"cuda\". There were other node types available, but compute20 and cuda were the most beneficial nodes for CFD analysis in the available HPC system.  
The interconnection between the nodes was a two-level fat-tree Intel Omni-Path network. This network is a particular optical fiber network for HPC systems, designed for high parallel bandwidth and low parallel latency. The Omni-Path technology is similar to the open industry standard Infiniband with connection speeds up to 100 Gib/s [21]. The network throughput of the HPC system reached around 6.259 Gib/s within ANSYS Fluent, while the network latency was, on average, 1.598 \(\upmu\)s. The operating system was CentOS version 7. As a resource manager and scheduler, we used PBS Torque in combination with Maui. At the time of the research, there were no restrictions on the wall time for team members of Elefant Racing.
# Performance of Different SLAM Algorithms for Indoor and Outdoor Mapping Applications
## 2 Materials and Methods
### HDL Graph SLAM  
HDL Graph SLAM is an open-source ROS (Robot Operating System) package for real-time 6 DOF SLAM using a 3D LIDAR [14]. It is based on 3D Graph SLAM with NDT [19] scan matching-based odometry estimation and loop detection.  
In the HDL Graph SLAM algorithm, the point cloud is downsampled, and then the sensor pose is estimated by applying the scan matching between consecutive frames. Floor plans are detected by the RANSAC method simultaneously. Finally, estimated odometry and detected floor planes are used for creating map points [2].
## 8 Discussion  
The study highlights the pivotal role of antioxidants in cosmetic formulations, emphasizing their ability to counteract the harmful effects of reactive oxygen species (ROS), which contribute significantly to skin aging, hyperpigmentation, and other oxidative stress-induced conditions. Both natural and synthetic antioxidants are extensively explored for their unique mechanisms of action and potential applications in promoting skin health and aesthetics. Natural antioxidants derived from plants, fungi, and algae are of particular interest due to their bioactive properties, biocompatibility, and low toxicity. Plant-derived antioxidants such as polyphenols (e.g., flavonoids, catechins, and tannins), carotenoids, and vitamins (C and E) are known for their ROS-scavenging properties, UV-protective effects, and ability to promote collagen synthesis. Extracts from medicinal plants such as _Silybum marianum_ (milk thistle) or _Camellia sinensis_ (green tea) have demonstrated significant antioxidant activity and are widely used in skincare formulations. These bioactives not only neutralize ROS but also exhibit anti-inflammatory and photoprotective properties, further enhancing their value in cosmetics. Fungi, particularly mushrooms like _Ganoderma lucidum_ (Reishi) and _Lentinula edodes_ (Shitake), are increasingly recognized as valuable sources of antioxidants, including polysaccharides, polyphenols, and ergothioneene. These compounds are not only effective in reducing oxidative damage but also enhance skinhydration and barrier function. Their growing popularity in cosmetics aligns with the trend toward sustainable and natural product development. Marine algae and microalgae are emerging as potent sources of antioxidants due to their high content of carotenoids (astaxanthin, fucoxanthin), polyphenols, and sulfated polysaccharides. Algae-derived bioactives provide strong protection against UV-induced damage, enhance skin elasticity, and exhibit anti-inflammatory properties, making them ideal candidates for anti-aging and sun-care products.  
The discussion also addresses key challenges in the practical application of antioxidants in cosmetics. One major hurdle is ensuring the stability and bioavailability of these compounds in formulations, as many natural antioxidants degrade upon exposure to light, oxygen, or high temperatures. Encapsulation technologies, such as liposomes and nanoparticles, are being developed to enhance their stability and delivery into deeper layers of the skin.  
Moreover, the potential synergistic effects of combining different antioxidants are an exciting area for future research. Studies suggest that mixtures of antioxidants, such as vitamins C and E or polyphenols and carotenoids, may provide enhanced protection by targeting multiple pathways of oxidative stress.
## 3 System Design and Platform Subsystems  
This section describes the system-level design of MeznSat and provides an overview of the subsystems used on-board. The spacecraft bus design includes five main subsystems that support the operation of the mission payloads. These are the Electrical Power Subsystem (EPS), the Attitude Determination and Control Subsystem (ADCS), the Command and Data Handling Subsystem (CDHS), the Telecommunications Subsystem (TS) and the mechanical subsystem. The overall system-level block diagram of MeznSat is shown in Figure 5.
## 4 Characteristic Test and Analysis of the FBG Dynamometry Bol
### Test Results and Discussion
#### 4.3.1 Analysis of the Results and Discussion of Test I
The correlation coefficient, range, linearity, and sensitivity of the resistive strain gauge and the FBG sensor are presented in Table 2.  
By analyzing Table 2, it can be concluded that the FBG sensor is close to the reference value of the resistance strain gauge in the above four indexes, which verifies that the designed FBG dynamometry bolt can replace the traditional resistance dynamometry bolt to monitor the stress of the bolt body. In terms of the measuring range and linearity, the FBG sensor is better than the strain gauge sensor.
## 2 Materials and Methods
### Antimicrobial Susceptibility Test
#### 2.4.3 Microdilution Method  
The broth dilution method was performed according to the indications of the National Committee for Clinical Laboratory Standards (NCCLS) [41], a frequent method used to study the antimicrobial activity in seaweed extracts [22; 42; 43]. For the susceptibility tests, non-treated and round-bottom 96-well microplates (Fisher Scientific) with 170 uL of Muller Hinton Broth (MHB) supplemented with 1.5 % NaCl were inoculated with 10 uL of standardized inoculum and 20 uL of each extract (50 mg mL\({}^{-1}\)) (\(n=8\)). Plates were incubated at the optimal temperature of each strain for 18 h. The antimicrobial activity was detected by the reduction of the visible turbidity measured by recording of the optical density (OD\({}_{600}\)) in a plate reader (Spectrophotometer Thermo Scientific, Evolution 201). Results were expressed as a percentage of inhibition using Equation (2).  
\[\%\ inhibition=\left[1-\frac{Abs\ ext}{Abs}\right]\times 100 \tag{2}\]  
where \(Abs\ ext\) is the absorbance measured in the wells that contain bacterial strain growing in the presence of the extract and \(Abs\) refers to the same measure in wells that contain the bacterial strain.
###### Abstract  
As a new high-resolution spaceborne SAR observation mode, sliding-spot imaging has the characteristics of a large squint, long aperture time, and azimuth aliasing, and because of the dechirp operation in the imaging algorithm of this mode, it is difficult to construct a direct range-Doppler equation for its geometric processing. In this paper a conformation model based on an antenna pointing vector is presented, which fully considers the influence of the dechirp operation on the range image, starts from the relative position of the dechirped range image points and the satellite, and establishes a strict conversion model between the image coordinates and geographic coordinates using the accurate satellite-ground geometric conditions. Then the forward and reverse formulas for geometric processing of the sliding-spot mode are given based on this model. Finally, geometric calibration and positioning experiments under different conditions and field spaceborne SAR data are executed. Results show that after geometric errors caused by the SAR payload have been calibrated and other factors such as atmospheric delay, platform position, and elevation error have been compensated, the uncontrolled geometric positioning accuracy can reach within 1 m-2 m, which fully proves the effectiveness of this method in the geometric positioning of high-resolution sliding-spot images.  
SAR; sliding-spot mode; squint; dechirp; range-Doppler; geometric calibration; geometric positioning accuracy
## 4 Case Studies
### Three-Dimensional Point Cloud of San Cono Bridge  
In order to build the 3D model of the bridge, the photogrammetric survey was divided into an aerial and a terrestrial one. Taking into account the scale of representation (SR) and the aim of the project, a Ground Sample Distance (GSD) equal to 1 cm was chosen as reference for the survey. The terrestrial survey was carried out in order to survey the lower part of the bridge using a Canon EOS 100D DSLR camera (Charged Coupled Device -CCD size = 4.29 \(\upmu\)m) with a focal length of 18 mm. A total amount of 400 terrestrial images was acquired. As regards the aerial survey, this was carried out using a UAS Xiaomi Mi 4K, a multi-copter rotary wing weighing less than 1.5 kg and whose declared maximum speed is 18 m per second (about 65 km/h). This UAV was developed and produced by Flymi, a company of Mi Ecosystem. The photogrammetric features of the camera mounted on UAV platform were: CCD size = 4.29 \(\upmu\)m and focal length of 3.5 mm. The aerial survey was designed using a software called Mission Planner, which is developed by Oborne for the open-source APM autopilot project. The flight plan was designed with the following characteristics [23]: 80% longitudinal (end-lap) and 60% transversal overlap (sidelap). In addition, flight lines (FLs) inclined at 30\({}^{\circ}\) and 45\({}^{\circ}\) were designed in a direction longitudinal to the bridge in order to increase the rigidity of the aerial photogrammetric block and, at the same time, to increase the redundancy of information with the data obtained from the terrestrial survey. In total, 285 images were taken during the aerial survey.  
The post-processing of terrestrial and aerial images was carried out using Agisoft Metashape software. In this case study, two separate chunks were built: one involving aerial (UAV) surveying and another involving terrestrial surveying. To evaluate the quality of image matching (alignment step), the number of the projections and the error achieved on the single chunk were taken into account. Table 3 shows the high quality of the image matching and, consequently, the correctness in the phase of acquisition, for both the aerial and the terrestrial surveys.  
According to the photogrammetric pipeline, a dense point cloud was built for both datasets. Consequently, in order to obtain the model of the bridge under investigation, it was necessary to integrate the two datasets on the basis of common points. In total, the final 3D point cloud consisted of approximately 8 million points (Figure 8). Subsequently, the model was scaled using 12 Ground Control Points obtained through a traditional topographic survey.  
\begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Dataset**} & \multicolumn{2}{c}{**Projections (\#)**} & \multicolumn{2}{c}{**Error (Pixel)**} \\  & **min** & **max** & **min** & **max** \\ \hline Aerial & 1831 & 2426 & 0.524 & 0.8427 \\ Terrestrial & 4031 & 5114 & 0.622 & 0.247 \\ \hline \end{tabular}
\end{table}
Table 3: Report on image matching for the two datasets.  
Figure 7: Three-dimensional (3D) point cloud of San Nicola in Montedoro.
# Instantaneous Reactive Power Theory in the Geometric Algebra Framework
## 6 Conclusions  
In this study, a systematic development of the IRPT in the framework of geometric algebra (GA) was carried out. The most relevant definitions and theorems about power variables, current terms, and compensation principles in the IRTP environment were established. For this, the GA mathematical tool was used, which introduces a unified methodology to a multidimensional problem such as that of electrical power. In this way, a single mathematical object called an instantaneous power multivector was defined, which encompasses both the instantaneous power and the different variables of instantaneous reactive power. From there, it was possible to obtain the current and each of its orthogonal components: instantaneous power current and instantaneous reactive current. The approach followed here requires neither coordinate transformations nor mathematical transformations; the waveforms of voltages and line currents are handled directly.  
The approach followed was to first carry out an analysis of three-phase systems, to later obtain their subsequent generalization to multi-phase systems. Thus, it was shown that an IRPT development is possible for any number of phases, where the power variables are contained as components of the same mathematical entity.  
Logically, the power variables and the current terms presented coincide with those included in the technical literature in the traditional proposals. In the same way, the fundamentals of compensation--instantaneous time compensation (TIC) and time average compensation (TAC)--within the framework of the proposed formulation, were established. Finally, the methodology developed was applied to two practical examples. First, the case of a five-phase system was considered. The currents before and after the use of both types of compensation (TIC and TAC), and the power balance, were shown. Then, in order to show the effective use of the proposed methodology in a real engineering case, a non-sinusoidal unbalanced three-phase system with neutral conductor was presented.  
Conceptualization, P.S., J.L.F.-G. and J.A.G.-G.; Data curation, P.S. and J.L.F.-G.; Formal analysis, P.S.; Investigation, P.S., J.L.F.-G. and J.A.G.-G.; Methodology, P.S. and J.L.F.-G.; Resources, P.S.; Software, P.S., J.L.F.-G. and J.A.G.-G.; Supervision, P.S. and J.A.G.-G.; Validation, P.S., J.L.F.-G. and J.A.G.-G.; Visualization, P.S.; Writing--original draft, P.S., J.L.F.-G. and J.A.G.-G.; Writing--review and editing, P.S. All authors have read and agreed to the published version of the manuscript.  
Figure 12: (**a**) Neutral current for case 2 before/after TIC. (**b**) Neutral current for case 2 before/after TAC. Compensation at t = 0.06 s.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.