esa-sceva/satcom-chunk-collection huggingface dataset:
## 7 Algorithms for HPC Systems in the Exascale Era
### Parallel Solvers for Exascale Computing
#### 7.2.1 \"Implicit-Explicit\" and \"Parallel in Time\"
To complete the computation of \(\mathbf{u}_{n+1}^{k+1}\), task \(p\) should eventually send the vector \(\mathbf{w}_{n}^{k}\) to its right neighbor task \(p+1\) and should receive the vector \(\mathbf{z}_{n-1}^{k}\) from its left neighbor task \(p-1\). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Methods** & \(\mathbf{\mathrm{B}}_{1}^{0}(\mathbf{u}_{n+1}^{k})\) & \(\mathbf{\mathrm{B}}_{1}^{1}\Big{(}\mathbf{u}_{n}^{k+1}\Big{)}\) & \(\mathbf{\mathrm{B}}_{1}^{0}(\mathbf{u}_{n}^{k})\) \\ \hline DBJ & \(I-\omega I\) & \(\omega\phi^{-1}\chi\) & \(-\) \\ ABJ & \(I-\tilde{\phi}^{-1}\phi\) & \(\tilde{\phi}^{-1}\chi\) & \(-\) \\ ABGS & \(I-\tilde{\phi}^{-1}\phi\) & \(-\) & \(\tilde{\phi}^{-1}\chi\) \\ Parareal & & \((\phi^{-1}-\tilde{\phi}^{-1})\chi\) & \(\tilde{\phi}^{-1}\chi\) \\ TMG & \((1-\omega)\Big{(}I-T_{c}^{T}\phi_{c}^{-1}T_{c}^{T}\phi\Big{)}\) & \(\omega\Big{(}\phi^{-1}-T_{c}^{T}\phi_{c}^{-1}T_{c}^{T}\Big{)}\chi\) & \(T_{c}^{T}\phi_{c}^{-1}T_{c}\chi\) \\ TMG\({}_{c}\) & \(-\) & \(\left(\phi^{-1}-T_{c}^{T}\phi_{c}^{-1}T_{c}^{T}\right)\chi\) & \(T_{c}^{T}\phi_{c}^{-1}T_{c}^{T}\chi\) \\ TMG\({}_{f}\) & \(\left(I-T_{c}^{T}\phi_{c}^{-1}T_{c}^{T}\phi\right)(I-\tilde{\phi}^{-1}\phi)\) & \(\left(\tilde{\phi}^{-1}-T_{c}^{T}\phi_{c}^{-1}T_{c}^{T}\phi\tilde{\phi}^{-1} \right)\chi\) & \(T_{c}^{T}\phi_{c}^{-1}T_{c}^{T}\chi\) \\ PFASTST & \(\left(I-T_{c}^{T}\tilde{\phi}_{c}^{-1}T_{c}^{T}\phi\right)(I-\tilde{\phi}^{-1} \phi)\) & \(\left(\tilde{\phi}^{-1}-T_{c}^{T}\tilde{\phi}_{c}^{-1}T_{c}^{T}\phi\tilde{\phi}^{ -1}\right)\chi\) & \(T_{c}^{T}\tilde{\phi}_{c}^{-1}T_{c}^{T}\chi\) \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Summary of the the most popular _P_Int_ methods and their block iteration operators, where \(\omega>0\) is a relaxation parameter, \(T_{C}^{F}\) and \(T_{F}^{C}\) are transfer operators from _“coarse to fine”_ and _“fine to coarse\"_ time blocks, respectively, and where \(\phi_{C}\) is the time integration operator on a coarse time block.
## 6 Discussion  
A prototype of a single detecting cell in the form of a double-folded slot narrow-band antenna for the LSPE experiment has been developed. During this stage, technological issues of fabrication of these antennas were investigated, the influence of the length of coplanar lines and capacitances of SIN junctions on the operating frequency of the receiving system was checked. This allowed selecting a double-folded slot receiving system with the coplanar line, having smooth amplitude-frequency characteristic centered at 240 GHz, which can be used for further design of double frequency 220/240 GHz receiver for LSPE mission. Based on these results, 2-D array of double-folded slot antennas with CEBs as 220/240 GHz LSPE channel prototype was calculated.  
A double-folded slot antenna with coplanar lines represents a type of planar antenna, which is suitable for cosmology projects due to its compactness, flexibility of adjustment, and ease of fabrication. This antenna can be used for a wide range of tasks with multi-frequency systems.  
Conceptualization--L.S.K., S.M. and P.d.B.; Methodology--L.S.K., S.M., P.d.B. and A.L.P.; Formal analysis--L.S.K., A.L.P., L.S.R. and A.V.G.; Investigation--L.S.R., D.A.P., A.V.B., A.V.G., A.L.P., A.V.C., I.V.R. and V.O.Z.; Data curation--L.S.R., D.A.P., A.V.B., A.V.G. and A.L.P.; Writing--original draft preparation--L.S.R., D.A.P., A.V.G., A.L.P. and A.V.C.; Writing--review and editing--L.S.K., A.L.P., S.M. and P.d.B.; Supervision--L.S.K. and A.L.P.; Project administration--A.L.P.; Funding acquisition--A.L.P. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Center of Excellence <<Center of Photonics>> funded by The Ministry of Science and Higher Education of the Russian Federation, contract No 075-15-2020-906.  
Not applicable.  
The data that support the findings of this work are available from the corresponding author upon reasonable request.  
Figure 7: Frequency response curves of the receiving system for LSPE ancillary channels 220 GHz (blue curve) and 240 GHz (red curve).  
Conflicts of Interest: 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.
# A Systematic Review of Ship Wake Detection Methods in Satellite Imagery
## 3 Results
### Introduction to DL-Based Methods for Wake Detection
#### 3.3.1. Backbone, Neck, and Heads
Throughout this evolution process, different paradigms have emerged, like single-stage and two-stage detectors, as well as anchor-based and anchor-free architectures. The following subsections serve to highlight some of these differences, accompanied by state-of-the-art examples.
# A Synthetic Aperture Radar-Based Robust Satellite Technique (RST) for Timely Mapping of Floods
###### Abstract  
Satellite data have been widely utilized for flood detection and mapping tasks, and in recent years, there has been a growing interest in using Synthetic Aperture Radar (SAR) data due to the increased availability of recent missions with enhanced temporal resolution. This capability, when combined with the inherent advantages of SAR technology over optical sensors, such as spatial resolution and independence from weather conditions, allows for timely and accurate information on flood event dynamics. In this study, we present an innovative automated approach, SAR-RST-FLOOD, for mapping flooded areas using SAR data. Based on a multi-temporal analysis of Sentinel 1 data, such an approach would allow for robust and automatic identification of flooded areas. To assess its reliability and accuracy, we analyzed five case studies in areas where floods caused significant damage. Performance metrics, such as overall (OA), user (UA), and producer (PA) accuracy, as well as the Kappa index (K), were used to evaluate the methodology by considering several reference flood maps. The results demonstrate a user accuracy exceeding 0.78 for each test map when compared to the observed flood data. Additionally, the overall accuracy values surpassed 0.96, and the kappa index values exceeded 0.78 when compared to the mapping processes from observed data or other reference datasets from the Copernicus Emergency Management System. Considering these results and the fact that the proposed approach has been implemented within the Google Earth Engine framework, its potential for global-scale applications is evident.  
Sentinel 1; SAR-RST-FLOOD; flood mapping and monitoring; Google Earth Engine; CEMS; multi-temporal Article
## 4 SBAS InSAR Results and Precision Validation  
### SBAS InSAR Results  
Based on the SBAS deformation results in the line-of-sight direction we calculated the deformation rates in the vertical direction. All deformations mentioned below are vertical deformations. It should be noted that our monitoring approach utilizes Sentinel-1A data in the C-band, which, due to its radar imaging properties, may not fully penetrate the bridge structure. However, due to the transmission of deformations and displacements, changes in the bridge structure can manifest themselves on the bridge surface, and therefore, our study aims to comprehensively monitor the structural changes in the bridge and any resulting surface deformations. The SBAS-InSAR results showed the deformation rates ranging from \(-18.2\) to \(15.4\) mm/year in the study area (bridge body and area around the bridge) as shown in Figure 4, and we divided the deformation rates into eight categories at equal intervals (shown in the legend of Figure 4). The deformation rate along the bridge ranged from \(-15.6\) to \(10.7\) mm/year. We conducted a statistical analysis of the deformation rates of \(163\) points on the bridge, and the results are shown in Figure 5. According to Figure 5, the overall deformation approximated a normal distribution (red curve), and we calculate that \(\mu\), the mean rate of deformation points is \(2.67\) mm/year. In addition, the points with deformation rates ranging from \(-3.17\) to \(8.51\) mm/year account for \(95\%\) of the total deformation points. Therefore, the bridge can be regarded as basically stable.  
Figure 3: SBAS InSAR Workflow.
## 3 Air-Ground NLOS Identification Method Aided by 3D Terrain Modelling
### Air-Ground NLOS Identification Based on Visible Vector Masking  
After obtaining the approximate position of the user, the elevation angle and azimuth of each signal transmitter are calculated.  
As shown in Figure 8, the Cartesian coordinates of the user in the ECEF coordinate frame are \((x_{1},y_{1},z_{1})\), and the Cartesian coordinates of the signal transmitter in the ECEF coordinate frame are \((x_{s},y_{s},z_{s})\); therefore, the relative distance, azimuth and elevation angle of the signal transmitter to the user are calculated.  
If we take all the 3D terrain modelling data into consideration, mass computation will slow down the program. To improve the simulation speed, this article calculates only terrain that is less than 300 m away from the user. For terrains greater than 300 m away from the user, the cover angle is very low. For example, a building that is 50 m tall only covers users for less than \(10^{\circ}\).  
The terrain cover range is calculated after selecting the octree terrain near AM. Taking the position of the user as the origin, the surrounding azimuth angles are sampled. At each sampled azimuth \(\theta\), the terrain cover limit including the terrain cover angle \(\beta_{\mathit{ terrain}}\) and the maximum visible distance \(r\) are calculated. At azimuth \(\alpha\) of the signal transmitter, the visibility is predicted according to the following equation:  
\[Visibility=\left\{\begin{array}{ll}visible,&\beta_{\mathit{ transmitter}}>\beta_{\mathit{ terrain}}\\ visible,&\beta_{\mathit{transmitter}}<\beta_{\mathit{ terrain}},d<r\\ invisible,&\beta_{\mathit{transmitter}}<\beta_{\mathit{ terrain}},d\geq r\end{array}\right. \tag{2}\]  
The transmitter elevation angle \(\beta_{\mathit{transmitter}}\) and the terrain angle \(\beta_{\mathit{ terrain}}\) are then compared. If the transmitter elevation angle \(\beta_{\mathit{transmitter}}\) is larger than the terrain cover angle \(\beta_{\mathit{ terrain}}\), then the user and transmitter are visible to each other. If the transmitter elevation angle \(\beta_{\mathit{transmitter}}\) is lower than the terrain cover angle \(\beta_{\mathit{ terrain}}\), compare the visible distance \(r\) with the relative distance \(d\). If \(d<r\), the signal transmitter is visible. If \(d\geq r\), the transmitter and user are not visible to each other. The signal received is NLOS signal and should be excluded.  
Figure 8: Elevation angle and azimuth of the signal transmitter.  
By this method, we can exclude NLOS signals more precisely and obtain high positioning accuracy.
## 2 Double-Stranded DNA Recognition by Peptide Nucleic Acid (PNA)
### Double-Duplex Invasion by Pseudo-Complementary PNAs (pcRNAs)  
Double-duplex invasion requires a pair of complementary PNAs. Since PNA/PNA is more stable than PNA/DNA, duplex formation between these complementary PNAs preferentially proceeded over invasion complex formation, resulting in lower invasion efficiency. To suppress the formation of PNA self-duplexes, pseudo-complementary PNA (pcRNA) has been used [33; 42; 63] (Figure 5). In pcRNA, conventional adenine (A) and thymine (T) nucleobases are replaced by the artificial pseudo-complementary nucleobases, 2,6-diaminopurine (D) and 2-thiouracil (U\({}_{\text{s}}\)), respectively (Figure 5a). Though stable base pairs between D\(\cdot\)U\({}_{\text{s}}\) and the natural nucleobases T\(\cdot\)A are retained (Figure 5b), pcPNA/pcPNA duplexes are greatly destabilized through the steric repulsion between the amino group of D and the thione group of U\({}_{\text{s}}\) (Figure 5c). Consequently, efficient double-duplex invasion complex formation is achieved by using pcRNAs, as pcPNA/pcPNA duplex formation is suppressed and PNA/DNA duplex formation is promoted [42].  
Thus, the strategy of pcPNA is very effective for invasion. Although a certain amount of A\(\cdot\)T needs to be included for efficient invasion, pcPNA does not have significant sequence restrictions like the homopurine/homopyrimidine sequences of triplex or duplex invasion described above. Therefore, double-duplex invasion is effective for various DNA recognition applications, especially intracellular and in vivo applications, due to its ability to recognize dsDNA directly. In this review, we focus on double-duplex invasion, which has high sequence flexibility among invasion complexes, and the related studies are summarized below (in the following, unless otherwise stated, invasion refers to double-duplex invasion).
## 2 Related Work
### Privacy-Preserving Location-Based Query
[15] proposed a fine-grained privacy-preserving location-based service (LBS) framework called FINE. This framework employs a ciphertext-policy anonymous attribute-based encryption technique to ensure fine-grained access control, location privacy, and the confidentiality of both the LBS data and its access policy, while providing accurate LBS query results without involving any trusted third party. In comparison to non-cryptographic schemes, these approaches offer significantly stronger privacy protections and consistently produce exact query results that match those obtained from queries over plaintext location data. Nevertheless, employing these cryptographic methods imposes significant computational and communication overhead on telecommunication operators and businesses. However, the above two types of location query-based schemes are based on traditional cloud computing scenarios, and the hardware security protection level is relatively low compared to the TEE-based schemes. Moreover, due to the existence of TEE, the latter has a huge advantage in client computing and communication overhead. In terms of efficiency, although the overall computing overhead of the server will increase in the TEE-based scheme, the computing efficiency inside the TEE is significantly higher than other privacy protection schemes. Therefore, in the TEE-based scenario, the way in which to achieve the optimal location query in terms of security and performance is the focus of our research.
## 4 Results and Discussion
### Effect of Vibration on the Apparent Viscosity  
#### 4.3.1 0.25 g Vibration at Different Frequency  
Figure 12 shows the time-domain apparent viscosity of the melt inside the extrusion liquefier obtained by DMMFB and FEA without and with different-frequency vibration applied, of which the amplitude is 0.25 g and the frequency is, separately, 100, 200, 300, 400 and 500 Hz. It can be seen that when vibration is applied, the apparent viscosity changes periodically with time as the shear stress changes from a constant to a periodic variation, according to Equation (A8). Generally, both values and trend of the analytical apparent viscosity agree well with the simulated ones.  
Table 9 gives the effective apparent viscosity of the melt inside the extruder liquefier for each condition. The viscosity is decreased with the application of vibration and further decreased with the increase of vibration frequency. For example, when no vibration is applied, the effective value of the viscosity predicted by DMMFB is 3601 Pa-s, when the frequency of the applied vibration is 200 Hz, the value is reduced down to 2220 Pa-s, decreased by 38.4%, and when the frequency is 300 Hz, the value is further reduced to 1760 Pa-s, decreased by 51.1%. This is because the apparent viscosity of the melt is reduced with vibration applied, and it is further reduced when the vibration frequency is  
Figure 11: Effective value of the shear stress without and with different-amplitude vibration applied.  
Figure 12: The apparent viscosity of the melt inside the extrusion liquefier without and with 0.25 g vibration applied at different frequencies. (**a**) No vibration applied, (**b**) 100 Hz, (**c**) 200 Hz, (**d**) 300 Hz, (**e**) 400 Hz, (**f**) 500 Hz.  
increased [27; 28]. In addition, due to the close relationship between apparent viscosity and shear stress according to Equation (A8), the changing situation and trend are similar to those of the shear stress, as discussed previously.
# Usability and Affects Study of a Virtual Reality System Toward Scorpion Phobia Exposure Therapy
## 3 Results  
### Usability Testing Findings  
Related to self-reported scorpion fear, 9.8% of participants reported considerable fear, while 90.2% reported a low level of fear. The average usability score based on the System Usability Scale (SUS) [57] for all participants using the VRET system toward scorpion phobia was 75.49. Although an average value for the SUS score for virtual environmentshas not been determined, previous research studies indicate an average SUS score of about 68 [64]. Then, if your score is less than 68, there are probably serious problems with the app. In this study, the participants reflected a generally positive perception of usability. To detail the perceptions of the participants for each question, Table 1 shows the raw value (Likert scale) answered by all participants.  
Regarding the frequent use of the system (\(Q_{1}\)) as possible, in general, participants show a neutral position, and women tend to increase the likelihood. In relation to complexity, the participants disagree that the system is unnecessarily complex (\(Q_{2}\)). Most of the participants agree that the system is easy to use and that no technical help is needed to use it (\(Q_{3}\) and \(Q_{4}\)). The integration of functions of the system is assessed with \(Q_{5}\) and \(Q_{6}\), where the general experience tends to agree that the system is well-integrated. In addition, the answers concerning the system can be quickly learned by other people and the confidence in the system (\(Q_{7}\) and \(Q_{9}\)) is biased toward strongly agreeing. Finally, \(Q_{8}\) and \(Q_{10}\) are geared toward investigating difficulties and need to learn many things before using the system. The participants strongly disagree that the system is cumbersome to use and requires a significant amount of prior knowledge. Although the sex-imbalanced sample does not allow us to make a comparative study, we present the values by sex descriptively in the results section. An overview of the results of the usability study follows, with recommended changes for areas where users found advantages and recommendations.  
Favorable findings  
* The experience is interesting; it feels like you are there, as if everything is real.
* They all found the drop-down menus and multimedia objects attractive.
* The system is easy to use and easy to understand.
* Users commented that the virtual world fit well on the screen.
* The size and speed of the scorpion is adequate. Recommendations  
The following is a list of the top user recommendations, and some of them were considered to reengineer this version.  
* More levels in the menu are required.
* Implement other places or cases to be able to navigate.
* Add instructions so that the user knows what to do when it is running.
* They could add more and bigger scorpions for each level.
* Use of a haptic device for selection and navigation.
# A Reliable Publish-Subscribe Mechanism for Internet of Things-Enabled Smart Greenhouses
## 3 Research Methodology
### Message Standardization
#### 3.2.2 Scalability Considerations  
The proposed system incorporates several mechanisms to ensure scalability in handling an increasing number of subscribers and messages:  
* Hierarchical Categorization Mechanism: The proposed MQTT broker employs a hierarchical categorization mechanism for messages, which enhances the routing and processing of messages on both the broker and server sides. This system entails the specification of topics and payloads, where the subscriber receives updates on specific topics, and the publisher disseminates information accordingly. Our approach implements a uniform communication protocol that decreases the intricacy and processing duration on the server end. The categorization system optimizes the routing of messages to their intended recipients, reducing the quantity of extraneous data and improving the accuracy of the primary server's processing.
* Dynamic Topic Management: The system can dynamically manage topics based on the number of connected devices and their data types. This dynamic management allows the system to efficiently allocate resources and prioritize critical messages, ensuring timely delivery and processing even as the number of subscribers increases.
* Scalable Architecture: The architecture intends to be modular and scalable, enabling the incorporation of additional brokers and servers as required through the registration topic. This flexibility ensures that the system can grow to accommodate a wide range of subscribers and increased message volumes without requiring significant redesign.  
These scalability features collectively ensure that the proposed system can effectively handle a growing number of subscribers and messages, maintaining performance and reliability in real-world applications.
# Seismic Response and Damage Analysis of an Isolated Bridge Subjected to Near-Fault Ground Motion
## 3 Results and Discussion  
### Seismic Response Analysis of Bridge  
The seismic response of the isolated bridge and the non-isolated bridge under the near-fault ground motion was studied. Fourteen near-fault ground motions (from the Chi-Chi, Kocaeli, Northridge and Loma Prieta earthquakes) had been selected for analyzing the seismic response of the isolated and non-isolated bridges. Under the TCU102 ground motion, the piers of the isolated bridge and non-isolated bridge suffered the most severe damage. Then, the TCU068 ground motion in the Chi-Chi earthquake, which is the typical near-fault ground motion, is selected in the analysis. The spatial differential effect of ground motion is not considered, and the uniform excitation is used for the ground motion input. The acceleration amplitude of the ground motion in the E direction is larger than that in the N direction. Then, the E direction of the selected ground motion record is input in the longitudinal direction (X-direction) of the bridge, and the PGA is 0.51 g. The N direction of the ground motion record is input in the lateral direction (Z-direction) of the bridge, and the PGA is 0.37 g. The V direction is input in the vertical direction (Y-direction) of the bridge, and the PGA is 0.53 g.  
The acceleration spectra of the TCU068 ground motion are shown in Figure 9. The natural periods of the non-isolated bridge and isolated bridge are 0.73 s and 2.50 s, respectively. Both in the X-direction (TCU068-E direction) and the Z-direction (TCU068-N direction), the spectral accelerations corresponding to the natural period of the non-isolated bridge are about 0.8 g. The spectral acceleration corresponding to the natural period of the isolated bridge in the X-direction is 0.75 g, while that in the Z-direction is about 0.35 g.  
Figure 8: The restoring force–displacement relationship of the isolation bearing model. (**a**) X-direction. (**b**) Z-direction.  
The isolation bearing model plays the role of isolation only in two horizontal directions (X-direction and Z-direction). Therefore, the analysis only focuses on the response of the bridge in two horizontal directions. It was found that the seismic response trend of each pier is basically consistent. Then, pier P2 and its corresponding bridge girder B2 point (shown in Figure 1) are selected for analysis.