esa-sceva/satcom-chunk-collection huggingface dataset:
# A Study on the Effects of Vertical Mass Irregularity on Seismic Behavior of BRBFs and CBFs
## 5 Conclusions  
Architecture and application of a structure play a major role in its seismic behavior. Today, given the limited available land and its high price in densely populated cities, structural designers have no choice but to design structures with irregularities in the plan and height. An accurate engineering judgement of the complicated behavior of irregular buildings during earthquakes plays a key role in improving the design quality of these structures. This study evaluated the seismic responses of eight regular and irregular 10- and 15-story CBF and BRB frames using the records of 12 far-field earthquakes. According to classification of HAZUS-MH MR5 [59] regulation, 10- and 15-story buildings are considered as high-rise buildings. The following results are obtained by undertaking nonlinear time-history analysis for modeling the frames:  
* Based on the results of the nonlinear time history analyses, regardless of the regularity status of the frames, the mean drift is lower in the CBFs than BRBFs. In other words, the CBFs improve the drift performance in comparison with the BRBFs. Compared to using CBFs, employing the BRBFs increase the mean drift by 47% and 77% in the irregular 10-story and 15-story frames, respectively. Furthermore, the maximum drift is higher in the frames with BRBs than in those with CBFs irrespective of their number of floors and regularity. With the largest magnitude among the 12 selected records, [PERSON] earthquake (Kocaeli, Turkey) also imposes the highest drift on all the eight studied frames.
* In contrast to the 10-story frames, using the BRB increase the base shear as a design parameter in both the regular and irregular 15-story frames. Moreover, the maximum base shear is observed in the 10-and 15-story MIR-BRBF.
* Negligible differences are ultimately observed in the mean value of the maximum floor acceleration between the four regular and irregular 10-story frames with either CBFs or BRBs. In contrast, the mean value of the maximum acceleration is higher in the 15-story frames with BRBs than in those with CBFs.
* An earthquake with the highest PGA among all the selected records imposes the highest acceleration on the top floors of all the eight frames. The maximum acceleration is also reported in the 10- and 15-story MIR-BRBFs.
* The maximum displacement of the top floor is higher in the frames with BRBs than in those with CBFs.  
Conceptualization, A.K. and S.S.; methodology, A.K. and S.S.; software, A.K.; formal analysis, S.S.; investigation, M.K.; data curation, M.K.; writing--original draft preparation, A.K. and S.S.; writing--review and editing, S.S., M.K. and A.K.; supervision, M.K. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The authors declare no conflict of interest.
## 2 Evolution of NMR Methodologies
### Solution-State NMR for Polysaccharides
#### 2.1.2 Conformational Dynamics
These simulations were essential in optimizing the sugar molecule's three-dimensional structure, allowing for more accurate conformational predictions than those based on RDC data alone. The integration of MD with NMR data helped resolve ambiguities in the sugar's conformation, enhancing the understanding of its structural dynamics [26]. MD simulations complemented NMR by providing dynamic perspectives, helping to validate and optimize structural and dynamic information. This integration allowed for a more comprehensive and accurate molecular model by combining the strengths of both experimental and computational methods.
## 4 Numerical Analysis and Experimental Verification
### Numerical Analysis Using Simulated Data
\begin{table}
\begin{tabular}{l c c c c} \hline  & **Fault** & **Imbalance-** & **Shaft-Bowing-** & **Equal** \\  & **Components** & **Dominant** & **Dominant** & **Equal** \\ \hline \(\tau<1\) & & & & \\  & \(U_{x}\) & 0.0323 & 0.3101 & \(4.69\times 10^{-5}\) \\  & \(U_{y}\) & 0.0581 & 0.3140 & \(6.01\times 10^{-5}\) \\  & \(s_{x}\) & 0.2924 & 0.0147 & \(1.37\times 10^{-5}\) \\  & \(s_{y}\) & 0.3398 & 0.0215 & \(1.66\times 10^{-5}\) \\ \(\tau\approx 1\) & & & & \\  & \(U_{x}\) & 0.0200 & 0.2937 & \(3.96\times 10^{-6}\) \\  & \(U_{y}\) & 0.0200 & 0.3295 & \(6.87\times 10^{-6}\) \\  & \(s_{x}\) & 0.3031 & 0.0238 & \(3.31\times 10^{-5}\) \\ \(\tau>1\) & & & & \\  & \(U_{x}\) & 0.0288 & 0.3557 & \(6.59\times 10^{-6}\) \\  & \(U_{y}\) & 0.0315 & 0.3008 & \(3.11\times 10^{-6}\) \\  & \(s_{x}\) & 0.3459 & 0.0105 & \(4.07\times 10^{-5}\) \\  & \(s_{y}\) & 0.2873 & 0.0221 & \(6.99\times 10^{-5}\) \\ \hline \end{tabular}
\end{table} 
Table 2: Comparison of RMSE values for fault components under different speed ratios. Figure 5: Frequency responses for imbalance and shaft bowing faults. As seen in Table 3, the RMSEs all fall in the order of \(10^{-5}\) and the effects of the damping on the accuracy are not significant.
## 4 Discussion
Future research efforts will focus on extending our model to incorporate 3D effects, integrating topographical information, enhancing fault modeling capabilities, considering noise in the training data, and developing a more versatile approach capable of handling different electrode configurations. By addressing these limitations, we aim to advance the field of DL-ERT inversion and improve its applicability to real-world scenarios.
# Doppler Shift Tolerance of Typical Pseudorandom Binary Sequences in PMCW Radar
## 4 Comparative Performance Analysis
### Investigated Pseudorandom Binary Sequences
#### 4.1.2 Gold and Kasami Sequences  
Gold sequences [27; 28] and Kasami sequences [29] are both PRBSs derived from m-sequences and therefore have length \(N_{\text{PRBS}}=2^{N_{\text{bit}}^{\text{MLS}}-1}\). Gold or Kasami sequences are generated in larger sets of orthogonal sequences than achievable sets of orthogonal m-sequences, being therefore usually used in code-division multiplexing (CDM) and code-division multiple access (CDMA) applications, such as MIMO operation of PMCW radar systems [17]. This, however, comes at the cost of increased sidelobe level in their PACFs, which will be investigated in further detail for a SISO-PMCW radar system in Section 4.2. Although relevant, the suitability of sets of orthogonal Gold and Kasami sequences for MIMO operation is left for a future study. Regarding PACF usable length, \(N_{\text{PRBS,usable}}=N_{\text{PRBS}}\) is assumed for Gold and Kasami sequences because the sidelobe level of their non-oversampled PACFs is homogeneous.
## 1 Introduction  
Global Navigation Satellite Systems (GNSSs) transmit satellite positions and clock offsets in a navigation message that enables real-time navigation on Earth and in space. In order to generate the message, a dynamic precise orbit determination and time synchronization (ODTS) is performed, mainly based on L-band observables--pseudoranges and carrier phases--collected by ground sensor stations deployed globally (in the case of Galileo and GPS) or regionally (Beidou and GLONASS). The ODTS process estimates a large number of nuisance parameters necessary for accurate modeling of satellite dynamics (e.g., solar radiation pressure), observation biases (e.g., antenna offsets), atmospheric delays, satellite and station clock offsets, and Earth rotation parameters for the transformation of orbits from inertial to an Earth-fixed frame [1]. This entails a computationally extensive processing of long data batches performed by the GNSS ground segment. Once the orbit determination is completed, orbital arcs are predicted, parametrized with a set of broadcast parameters, and encoded into the navigation message, which is then uploaded to the satellites. The accuracy of the broadcast ephemeris is currently at the level of decimeters to meters [1].  
Optical Inter-Satellite Links (OISLs) are being considered in GNSS to provide intersatellite ranging (ISR) and time-transfer capabilities [2; 3; 4]. By exploiting active ISR, capable of cm-level accuracy, classical Precise Orbit Determination (POD) can be significantly enhanced. It is shown in [5] that orbits can be estimated with sub-cm accuracy, with an improvement of one order of magnitude with respect to the capabilities of current GNSSs. It is of interest to investigate the potential of performing autonomous orbit determination using ISR as a primary observable, without exploitation of an extended network of ground sensor stations logging navigation data for subsequent processing.  
Direct estimation of the satellite Cartesian coordinates in an Earth-fixed frame with only ISR measurements would not be feasible in general due to rank deficiency of the system and rotational and translational ambiguities. Any orbit solution solely based on ISR would be ambiguous by a rotation and a translation of the entire constellation. This can be resolved by including Ground-to-Satellite Ranging (GSR) observations from ground reference stations, by parametrizing the orbit via a reduced number of parameters (here, we used the 15 Galileo F/NAV broadcast ephemeris, i.e., the classical six Keplerian elements complemented by nine correction parameters) and by batch-processing data collected over longer time intervals. The GSR measurements can be passive, e.g., Satellite Laser Ranging, or active, e.g., optical satellite-to-ground links.
## 1 Introduction
### Development of Empirical Equations for Corroded Pipe Failure Pressure Prediction  
[PERSON] and [PERSON] [25] developed an empirical equation for the prediction of the load-carrying capacity of locally corroded steel-plate girder ends based on an artificial neural network. [PERSON] et al. [4] applied this approach in an effort of developing an empirical equation for the failure pressure of medium toughness corroded pipelines with longitudinal interacting corrosion defects subjected to combined loadings. Based on their study, it was found that the development of an empirical equation using the weights and biases of an ANN shows promising results. The developed equations predicted the failure pressure of a corroded API 5L X65 with longitudinal interacting corrosion defects with a maximum percentage difference of 2.26%.  
While there are a few research studies [26; 27; 28; 29] on the effects of internal pressure and axial compressive stress on the failure pressure of a high toughness pipe with circumferentially aligned interacting corrosion defects, there are no analytical closed form solutions for the failure pressure prediction of high toughness corroded pipeline subjected to internal pressure and axial compressive stress. Despite being the most comprehensive failure pressure assessment method in the industry, the DNV code incorporates internal pressure and axial compressive stress for the assessment of single defects only. As for interacting defects, it considers internal pressure only.  
Furthermore, the DNV method was primarily developed to assess the integrity of low to medium toughness pipelines, as the validation of this method was based on full-scale burst tests conducted on pipes of grades API 5L X45 to API 5L X65 [12]. Hence, this method results in inaccurate failure pressure predictions when applied for high toughness pipes [6]. For these reasons, a DNV-like assessment method that incorporates combined loadings for the failure pressure prediction of high toughness pipelines with circumferentially aligned interacting corrosion defects is necessary. In addition, with empirical equations, failure pressure predictions can be obtained instantly, which is an important feature in time critical situations. Hence, an accurate and fast failure pressure assessment method is necessary for practical applications and the analysis of the failure pressure prediction of corroded high-toughness pipelines.  
In this study, an empirical equation for the failure pressure prediction of the commonly used API 5L X52, X65, and X80 pipes with circumferentially aligned interacting corrosion defects subjected to internal pressure and axial compressive stress was developed using the weights and biases of an ANN model that was trained using data generated using FEM.
# Siamese Tracking with Adaptive Template-Updating Strategy
## 3 Our Approach
### Siamese Tracking Network  
For most Siamese tracking networks, such as GOTURN and SiamFC, the first step is to zoom in on and crop input target images in the absence of target-feature information. In this process, when a target moves out of the bounding box, it is beneficial to add a margin to the context, but at the same time, this may lead to target-size reduction and the introduction of more background information. Siam FC is better than GOTURN for three reasons: first, its fully convoluted network structure makes offline training data highly identifiable; second, SiamFC uses a strictly supervised heat map rather than a recommended regression. Finally, the accuracy of the fusion tensor is improved by using a correlation layer as the fusion tensor, to which the success of correlation-based methods on visual-target tracking is owed. GOTURN uses regression results in the previous frame and updates the template in each frame, while SiamFC generates the template from basic facts in the first frame that in our system can be manually selected by operators. Feature similarity between template and search area is calculated by correlation operation, and a similarity heat map is generated. The highest response in the heat map represents the location of the target center in the next frame. In summary, the system realizes the tracking function from frame to frame.  
Figure 9 shows the architecture of our Siamese tracking network: First, the full convolutional network takes template and search area as inputs, respectively, and outputs features for the template and search area. Then, the heat map is generated through correlation of the similarity between template and search-area features. Last but not least, the target is tracked in the search area according to the highest response on the heat map.  
Figure 8: Outputs from template-update network under (**a**) deformation and (**b**) occlusion: left of each group, output from contour-detection network; right output from target-detection network.  
Configurations on kernel sizes and strides of convolutional layers in the Siamese network are summarized in Table 3. It needs to be noted that there are response-normalizing and intervening pooling layers connected to the outputs of the first two convolutional layers.
# Exploring Space Syntax Integration at Public Transport Hubs and Public Squares Using Drone Footage
## 2 Materials and Methods
### Study Locations  
Seven locations in Malmo, Sweden, were selected as suitable study locations. Malmo is a city in the south of Sweden with a population of about 340,000 people. The designated locations were either public squares or public transport hubs whose borders were chosen so as to include all pedestrian entrances to the location, i.e., the studied area should include a small part of the streets that enter/exit the square/hub.  
At each location, drone footage was recorded from at least one flight (15-20 min of video footage per flight). However, in two locations, two flights were needed to capture the entire study area in the camera view. To avoid flying over crowds, the flights were made at non-peak hours, between 9.00-12.00 and 13.00-16.00. Table 1 shows the seven locations and the number of flights made at each site and Figure 2 shows the camera view from the drone at one of the study locations. Further details about drone flights are described in the next Section 2.3.  
Figure 1: An isovist polygon from a specific starting location (the larger dot).  
Some practical details relevant to this study:  
* All calculations were made with MATLAB software using its built-in features for handling polygons and calculating the shortest path in a graph network.
* The roads, buildings and other unavailable areas were represented by polygons drawn by hand based on a combination of a satellite image and drone footage. Then, the isovist field was calculated by creating a line between two points and testing whether this line intersected with one of the polygons.
* The grid size used in this study is 2 m \(\times\) 2 m, compared to the 1 m \(\times\) 1 m used by [2]. This choice was made to limit the complexity of the resulting graph and to keep the integration calculation time to within 1 h per location. It should be noted that 1 m \(\times\) 1 m was tested at the first location without any noteworthy changes in the results.
## 2 NOAA Ocean Satellite Course
### Data Access Tools
#### 2.3.2. BerdAdapXtracto Package for R  
A common task in fisheries science is to extract satellite data along a set of latitude, longitude, and time coordinates representing the track of an animal fitted with a location tag (Figure 4) or a ship's station locations, a task which requires some degree of programming skill. To simplify this task, the rerddapXtracto R package was developed specifically for course participants to perform this data extraction on any gridded dataset on any ERDDAP for a user supplied set of latitude, longitude, and time coordinates [17]. In addition, satellite data can be extracted for an irregularly shaped area, such as a marine sanctuary or a fishery management area. Students are provided with a set of premade scripts that demonstrate the use of the functions in the R rerddapXtracto package [17]. This documentation is also available on the WCN website [23] and on GitHub [24].
# Energy-Efficient Multi-User Routing in a Software-Defined Multi-Hop Wireless Network
## 3 System Model  
This paper considers a QoS routing algorithm with multiple users, supposing that there are one SDN controller, some users, and \(N\) mobile devices with transmission capabilities. The SDN controller can periodically obtain information from mobile devices and optimize the routing in line with the global view of the network. Mobile devices refer to heterogeneous mobile wireless nodes such as smartphones, laptops, vehicles, sensors, and so on. Besides, these devices not only receive the broadcast information from the controller, but also return their own real-time state. The system architecture is shown in Figure 1, and the specific description is as below.  
* The SDN controller broadcasts information to each node, and these nodes form the backward paths to the controller based on the broadcast path;
* The state information of each node is sent to the SDN controller along the backward path. Then, the controller establishes the network topology according to the received information (residual energy, location);
* Before the users plan to send data to the target nodes, they shall send the transmission requests to the SDN controller;
* According to the global view and routing algorithm, the SDN controller calculates the transmission paths for multiple users at the same time and then sends them to each node;* Users send data to target nodes in terms of routing information.
# Corrosion and Scaling in Geothermal Heat Exchangers
## 6 Degradation Mitigation for Heat Exchangers
### Corrosion Resistant Alloys
Conversely, at Chaunoy, the samples were positioned in a flow-line pipe, exposed to high salinity geothermal water with traces of oil at 9.5 bar and 94 \({}^{\circ}\)C, with a flow rate of 6.25 L s\({}^{-1}\). The two fluids had different acidity levels a lower pH of 5.15 at Reykjanes and a pH of 7.15. at Chaunoy. Overall, the exposure conditions at Reykjanes are more aggressive due to higher acidity, temperature, pressure, and the presence of two phases in the fluid. On 316L SS, different layers formed at Reykjanes and Chaunoy. At Reykjanes, the deposit comprised an inner Cr and Mo-rich layer with an outer layer dominated by Fe oxides after exposure. In contrast, the corrosion layer at Chaunoy consisted of a single layer of Fe, O, and Cr with scattered defects across the surface, accompanied by traces of S and Si. Inconel 625 specimens exhibited subsurface cracks with depleted Cr and Ni content at both Reykjanes and Chaunoy. While the exact cracking mechanism was not definitively explained, the authors suggested that rapid temperature changes combined with the presence of brittle inclusions could be plausible causes. The 254 SMO alloys experienced localized attacks during exposure at Reykjanes, manifesting as pits, Cr-rich cracks, and subsurface voids containing O and S. Similar subsurface cracks were observed after exposure at Chaunoy, with the crack path aligning with Al and Si inclusions. The titanium material also exhibited subsurface cracking after Reykjane exposure and suffered from erosion in both exposure conditions. The authors concluded that titanium grade 2 was unsuitable for these geothermal conditions. All four materials displayed signs of degradation, primarily in the form of cracks, which necessitate further investigation to ascertain their root causes. Long-term exposures and reports on the evolution of thermal conductivity are imperative for qualifying these materials for heat exchanger applications. CRAs are effective for corrosion mitigation but do not address scale formation. For example, the titanium plate heat exchanger at Huka Prawn Farm requires frequent mechanical cleaning due to scale deposits [52].