esa-sceva/satcom-chunk-collection huggingface dataset:
# Advanced SDR-Based Custom OFDM Protocol for Improved Data Rates in HF-NVIS Links
## 2 Materials and Methods  
The test system was implemented using two USRP N210 SDRs (by Ettus Research, Mountain View, CA, USA) connected back-to-back through a power attenuator to simulate realistic signal conditions. Two laptops, each equipped with GNU Radio software, version 3.10, were used to develop and implement the OFDM transceiver and receiver. This setup allowed for the precise control and monitoring of the transmission and reception processes, enabling a thorough evaluation of the OFDM aggregated system's performance in a controlled laboratory environment. The use of the GNU Radio provided a flexible and powerful platform for developing and testing the OFDM modulation and demodulation schemes necessary for effective HF communication.  
OFDM with channel aggregation was implemented using the GNU Radio framework, augmented with Python blocks developed specifically for this project. The methods described include setting up the GNU Radio environment, building specialized computing blocks, and integrating and debugging these components within a simulated OFDM system.
# A pH Monitoring Algorithm for Orifice Plate Culture Medium
## 3 Algorithm Principle and Result Analysis
### Verification of Functional Model
#### 3.3.2 Error Analysis of Function Model  
In order to verify the feasibility of the function model established by the experiment, pore 1 and pore 3 in Table 4 were utilized for model validation. We took pictures at different locations, then calculated \(H_{ce}\), as shown in Table 5 below.  
The root means square error (RMSE) of the fitting curve is (does not contain well 5):  
RMSE \[=\sqrt{\frac{1}{n}\sum\limits_{i=1}^{n}{(y_{i}-\hat{y_{i}})}^{2}}\] (6) RMSE \[=0.1093\]  
The above experiments show that the culture medium was initially purple-red. After neutralizing in a carbon dioxide incubator for some time, it appeared bright red. Its average hue was reduced to between 0.01 and 0.02. Therefore, the average hue value of the image in the hole was calculated after obtaining the image, and if it was greater than 0.1, the image was acquired after 12 h.  
The averages of hue values were calculated from the hole plate images taken at different angles, and the pH values were predicted from the average of hue. The root means square error RMSE of the fitted curve was 0.1093. The error was small and the prediction accuracy was high. Therefore, the error of predicting the pH value of HSV using the average of hue was small, and the curve fitted satisfied the requirements of the F test and feasibility analysis. That is, it was feasible to use the average of the hue of HSV to monitor and predict its pH change.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Number** & \(H_{mean}\) & **pH** \\ \hline
1 & 0.013427 & 7.36 \\
3 & 0.010624 & 7.42 \\
5 & 0.965239 & 7.60 \\ \hline \hline \end{tabular}
\end{table}
Table 4: The three wells of the well plate contain the pH of the liquid and its \(H_{mean}\).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Number** & \multicolumn{5}{c}{\(H_{mean}\)} & **pH** \\ \hline
1 & 0.013427 & 0.013818 & 0.013914 & 0.016804 & 0.012618 & 0.01268 & 7.36 \\
3 & 0.010624 & 0.006117 & 0.008446 & 0.00916 & 0.00712 & 0.002938 & 7.42 \\
5 & 0.965239 & 0.968422 & 0.974566 & 0.974045 & 0.969344 & 0.961255 & 7.60 \\ \hline \hline \end{tabular}
\end{table}
Table 5: \(H_{mean}\) and pH value measured by pH meter of orifice plate images of 6-well liquid collected at different positions.
## 4 Experimental Results and Discussion
### Closed Loop Conditions  
As presented in Figure 16, at closed loop conditions using a PI and an IP controller, practical tests are made for the 3L_FOC for medium speed with changing direction as shown in Figure 17a,b, with injecting a perturbation as presented in Figure 17c,d, for small speed with changing direction as shown in Figure 17e,f, with injecting a perturbation as presented in Figure 18a,b.Those tests shows that the speed of the 3L_FOC has excellent performances in term of pursuit and rejection of perturbation. However, the 3L_FOC using an IP controller is still better in term of speed pursuit than a PI controller the latter also presents a peak, absent in the case of the IP controller.  
Figure 16: Comparison between 2L_FOC and 3L_FOC in open and closed loop conditions in terms of: (**a**) Current THD for 2L_FOC; (**b**) Current THD for 2L_FOC.  
Figure 15: Comparison between (**a**) 2L_FOC and (**b**) 3L_FOC in open and closed loop conditions in terms of Current distortions.  
Figure 17: Comparison between 3L_FOC in closed loop conditions using PI and IP controller in terms of: (**a**,**b**) Medium speed response with changing direction; (**c**,**d**) Medium speed response with injecting perturbation; (**e**,**f**) Small speed response with changing direction.
# Wavelet Transform Application for/in Non-Stationary Time-Series Analysis: A Review
## 3 Wavelet Transformation for Non-Stationary Time-Series: State-of-the-Art
### Application of WT in Geo-Sciences and Geophysics
[PERSON] and [PERSON] [30] used the wavelet transform in order to analyze the oxygen isotope ratio of the GISP2 deep ice core (Greenland) data. In fact, to evaluate the statistical significance of the Foster's wavelet spectrum, a non-parametric computing-intensive test was developed based on the Monte Carlo simulations.
## 3 Results and Discussion
### Hardness and Wear Performance  
The Vickers microhardness test results (Figure 15) demonstrate a regular increase in hardness with increasing B4C content. The highest recorded hardness was observed  
Figure 19: Corrosion rates (mm/year) based on Tafel extrapolation of all samples.  
Figure 20: Surface oxide resistance (\(\Omega\) cm\({}^{2}\)) from EIS of all samples.  
Figure 18: Electrical conductivity (%IACS) of all samples.  
in the CoCrMo-20B\({}_{4}\)C specimen. This increase is attributed to the enhanced resistance of the ceramic phase to plastic deformation. In a similar manner, wear tests (Figure 16) demonstrated that the wear loss decreases as the B\({}_{4}\)C content increases, particularly in Ti-B\({}_{4}\)C composites. These findings are consistent with the trends reported by [PERSON] and [PERSON] [36] and [PERSON] et al. [21].  
The wear performance of the materials was evaluated through pin-on-disk testing. As illustrated in Figure 16, there was a substantial decrease in wear rates with the incorporation of B\({}_{4}\)C in all alloy groups. The Ti-B\({}_{4}\)C composites demonstrated the most optimal wear resistance, particularly the Ti-20B\({}_{4}\)C.
# Continuous-Wave THz Imaging for Biomedical Samples
## 6 Conclusions and Perspectives
THz imaging allows the accurate distinction of tumours and normal tissue, but few studies have been able to illuminate the mechanism that causes this contrast. The fact of the high absorption of THz radiation by water contained in the organism is a crucial reason for the low penetration depth of THz waves. Therefore, the non-invasive feature of THz radiation can only be used for in vivo imaging except in the case of skin cancer. Currently, H&E-stained histology is used to determine the area of tumour resection, but it is time-consuming. So, sometimes, tissue freezing is used for ex vivo THz measurements, but this method sometimes leads to destruction of the tissue structure. Thus, THz imaging technologies applied in biomedicine still face the following challenges, which impede their clinical application. 1. The lack of high sensitivity, large dynamic range, and large number of pixels challenge the development of THz array detectors for the observation and recording of biological samples in real-time. 2. The lack of multiple and flexible THz beam shaping devices to achieve diffraction-limited spatial resolution and high-quality THz images. 3. The lack of THz waveguides for lossless transmission to access tissues. 4. The lack of an effective method to sustain the activity of tissue samples for a long time through THz imaging acquisition. THz imaging technology is an interdisciplinary research field at an early stage. Many of the imaging systems described in this article rely on the performance of the high-performance THz source, detector and imaging system. Biological tissue measurementsbased on modern THz instruments and methods require the cooperation of physicists, engineers, and medical personnel to be developed in the future. [PERSON], [PERSON] ([PERSON]), [PERSON] and [PERSON] searched and classified the literature; [PERSON], [PERSON] ([PERSON]), [PERSON], [PERSON], [PERSON] ([PERSON]) and [PERSON] wrote the manuscript; [PERSON], [PERSON] and [PERSON]. ([PERSON]) applied for the funding and managed the project. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Natural Science Foundation of China (62075001& 61675010), Science Foundation of Education Commission of Beijing (KZ202010005008), and Beijing Nova Program (XX2018072), and WBE Liver Fibrosis Foundation (CFHPC 2020021), and Beijing Dongcheng District Outstanding Talent Funding Project (2019 DCT-M-03). This work was supported by the National Natural Science Foundation of China (62075001&61675010), Science Foundation of Education Commission of Beijing (KZ202010005008), and Beijing Nova Program (XX2018072), and WBE Liver Fibrosis Foundation (CFHPC 2020021), and Beijing Dongcheng District Outstanding Talent Funding Project (2019 DCT-M-03). The authors declare no conflict of interest.
# Effect of Track Irregularities on the Response of Two-Way Railway Tracks
###### Abstract  
In predicting the response of track from a moving train only one track is generally considered. However, the effect of ground vibrations from one track and its effect on the nearby tracks has not been studied completely. Therefore, in the present paper, the effect of track irregularities and speed on the prediction of two-way tracks response is investigated. For this purpose, a three-dimensional dynamic finite element (FE) model capable of simulating interactions between the train and track by using a nonlinear hertz contact method was developed. The model uses tensionless stiffness between the wheel and rail to couple them. The model components including the sleeper, ballast, and soil domain are represented by solid brick elements. The rails are modeled as 3D Euler-Bernoulli beam elements. An iterative numerical algorithm was established for the integrations of the train and track interface. A comparative analysis was performed at various speeds and rail surface irregularity wavelengths. With the increase in speed, the results showed a significant increase in the adjacent tracks response and can induce much larger track vibrations at high frequency.  
Keywords:train-track interaction; track irregularities; finite element method; ground vibrations +
Footnote †: journal: Applied Sciences
###### Abstract  
This research evaluated the preservative properties of flour from the alga _Gelidium_ sp-, which is a waste substrate resulting from commercial phycocolloid extraction. Gelatin-based biofilms, which included two different concentrations of red alga flour, were developed and used as packaging systems during refrigerated storage (up to 9 days at 4 \({}^{\circ}\)C) of Atlantic Mackerel (_Somber scombrus_) muscle. In all batches tested, a progressive decrease in quality could be observed in the muscle of the fish as the storage time increased. Compared with the control fish, the _Gelidium_ alga flour extract had an inhibitory effect (\(p<0.05\)) on microbial activity (total aerobes, psychotrophs, and proteolytic bacteria), lipid oxidation (peroxide, thiobarbituric acid, fluorescence and polyene indices), lipid hydrolysis (formation of free fatty acids) and pH increase in refrigerated mackerel muscle. In contrast, no significant effect (\(p>0.05\)) was observed on trimethylamine formation, _Enterobacteriaceae_, or lipolytic bacteria counts. A preservative effect resulting from the incorporation of _Gelidium_ alga flour into the gelatin-based biofilm was observed, indicating both quality and safety enhancement. In accordance with current global interest in the search for natural and waste sources, a novel and beneficial use of _Gelidium_ flour for enhancing the quality of refrigerated fish has been proposed.  
Keywords:alga flour; aqueous extract; gelatin film; refrigerated mackerel; preservative effect +
Footnote †: journal: Applied
# Exploring Hybrid-Multimodal Routing to Improve User Experience in Urban Trips
## 3 Evaluation Framework  
This work proposes a method to combine different transportation modes for single urban trips. For each trip, we evaluate its duration, price, and user experience. Section 3.1 briefly introduces the concept that we use to evaluate urban trips. Section 3.2 describes the methodology used to combine transportation modes, produce multimodal-hybrid routes, and its evaluation. This solution explores real-time traffic data to replace trip segments using taxis with other transportation modes (e.g., bicycle or public transportation). In order to evaluate the hybrid-multimodal routes, we use datasets from the city of New York, available at the NYC Open Data portal ([[https://opendata.cityofnewyork.us/](https://opendata.cityofnewyork.us/)]([https://opendata.cityofnewyork.us/](https://opendata.cityofnewyork.us/)), accessed on 14 May 2021). We performed data reduction by clustering the main mobility flows due to their size, as described in Section 3.3. When looking for route choices, we run different nearest neighborhood and temporal queries. To reduce time executing these queries, we combine two different data indexes into a single data structure creating the Multi-Layer Geographical Linkstream, as detailed in Section 3.4.
# Adaptive Emergency Call Service for Disaster Management
## 5 Simulation Results  
### Test Environment  
The performance of the proposed 5G-SOS is assessed in AnyLogic(r) software. An emergency scenario in the Transverse city in Michigan, USA, with a number of devices varying between 5000 to 15,000 and 7 working gNBs covering an area of \(16.2\times 21\) km\({}^{2}\) is considered. This scenario is illustrated in Figure 6.
# Applying Topological Information for Routing Commercial Vehicles Around Traffic Congestion
## 4 Methodology and Model Development
### Diversion Model  
To select an alternative route that can accommodate heavy vehicle characteristics and restrictions, selection criteria were defined. The main characteristics for assessing whether a candidate route is feasible for truck traffic were specified as follows:  
1. Roadway geometry, including lane width and number of lanes;
2. Roadway conditions, including level of service and speed limit;
3. Heavy vehicle restrictions, including vertical clearance restrictions and insufficient bridge design loads;
4. Neighborhood impacts, including proximity to schools and hospitals.  
Collected data relevant to alternative route selection considerations were used as restrictions or scaled-cost barriers in the network analysis. Restrictions indicate that the selected road segment is restricted for heavy vehicles and is not feasible for truck traffic diversion. Scaled cost barriers penalize a route by increasing the travel time based on predefined factors.  
Barriers raise the cost of transport along edges and junctions of the linked network dataset. Barriers can be classified as points, lines, or polygons, and they can be modeled as preferred or avoided features within the Network Analyst extension to represent temporary changes to the network. When point barriers are added to a roadway segment, travel in the segment is prohibited. Added cost point barriers, however, still allow movement through them but may add costs to that movement. Line barriers are the second type of barrier within ArcGIS. Line barriers can restrict road segments entirely or can multiply travel costs by a given factor. The third type of barrier is the polygon barrier. A scaled cost can be added to roads that pass through a polygon barrier.
## 4 Discussion
### Surface Centroid Analysis  
For the different transverse sections along the patient body scans, the minimum average deviations from the reference system were located at the L-ASIS section (from 2.9 \(\pm\) 1.8 mm (medial/lateral) and 9.7 \(\pm\) 4.8 mm (anterior/posterior)) (Figure 6c), while maximum average deviations were found at the CLAV level (from 24.6 \(\pm\) 5.7 mm (medial/lateral) and 36.2 \(\pm\) 30.4 mm (anterior/posterior)) (Figure 6f). The location of the minimum average deviations supports the findings from the ALP analysis and is likely due to the pelvis being used as a reference for the alignment during the manual rectification process (Figure 6c). The average centroid deviations in the pre- and post-rectification mould were smaller than the deviations in the patient's body scan, indicating that, as expected, the deformity had been corrected to some extent during the casting and rectification processes (Figure 6g,h).  
The results showed a rectification trend of the centroid trajectories towards the vertical Z-axis of the reference system located at the pelvis for all the patients throughout the casting and rectification steps. This trend suggests that centroid locations of transverse sections can be used to characterise the rectification process to some extent, with regard to the alignment of the torso with respect to the pelvis. Analysis of centroid locations using transverse sections could be used to define rotation parameters in the transverse plane, helping to improve the characterisation of the 3D spinal correction followed during the rectification process.
# Comprehensive Study of IoT Vulnerabilities and Countermeasures
## 2 Preliminary Materials
### Internet of Medical Things  
Internet of Things devices find extensive use in the medical field, also known as the Internet of Medical Things (IoMT). IoMT is found everywhere today with wireless medical devices, widely used in hospitals, nursing homes, and homes (for personal health related use). Integrating IoT technology into the medical field has revolutionized healthcare delivery, offering numerous benefits and practical applications for healthcare services and patients. Adopting IoMT protocols offers numerous practical applications for medical device companies, health services, patients, and caregivers. For example, healthcare providers can collect real-time data on patient health conditions, such as the heart rate, blood pressure, temperature, SPO2 (blood oxygen saturation levels), and respiratory rate. This remote monitoring capability allows for spot checks, continuous patient monitoring, and the early detection of abnormalities in the patients' health. Patients can actively participate in their care using mobile applications that connect to IoMT devices, providing instant access to their health status and facilitating the self-management of chronic diseases, saving valuable time and enabling health services to focus on other tasks. IoMT facilitates the development of innovative solutions, such as the CardiacSense watch based on IoMT [9]. The CardiacSense watch incorporates sensors and interfaces such as the pulse rate, ECG recording, continuous detection of A-fib, unlimited event reports, manually added measurement values, general arrhythmia detection, threshold configuration, detailed event report, monthly reports, and sleep time tracking [10].
# Integrated System for Official Vehicles with Online Reservation and Moving Path Monitoring
## 2 System Architecture  
The system proposed in this study comprises four units: a set-top box, key cabinet, Line Bot, and a cloud database system (Figure 1). A user is allowed to make a reservation to use a vehicle through the Line Bot. Line Bot is used for push services in various applications such as students' learning to save cost and enhance communication [10; 11]. When the user pulls out a key and a set-top box from the key cabinet, the system activates the set-top box through radio-frequency identification (RFID) and sends the information to the cloud server. When the user returns the key and set-up box to the key cabinet, the official vehicle's information in the set-top box is delivered to the cloud database system to let the system be in waiting mode. The detailed functions of the four units of this system are described as follows.
# An Overview of Nanofiltration and Nanoadsorption Technologies to Emerging Pollutants Treatment
###### Abstract
Nanomaterials have gained prominence in properties, such as adsorption, porosity, chemical stability, reactivity, mobility, catalytic potential, antimicrobial activity, and recyclability. These characteristics make them promising approaches to remove/treat several organic and inorganic contaminants, biological toxins, pathogens, and dyes [18; 19; 20]. Nanofiltration membranes and carbon and metal-based adsorbent nanomaterials have been investigated for water treatment [19]. Treatment processes can occur by adsorption, filtration, and degradation to non-toxic compounds and intermediates [21]. These techniques have been successfully applied in the remediation of a wide range of contaminants such as pesticides, pharmaceuticals, and personal care compounds [22; 23]. Nanomaterials can be safely used for wastewater treatment, aiming for reuse of this resource, or for release into water bodies, as long as they comply with current legislation. Thus, the objective of this review was to address an overview and advances in the production and application of nanofiltration membranes and adsorbent nanomaterials for the treatment of effluents containing emerging pollutants.
# Research on Dynamic Modeling and Transition Flight Strategy of VTOL UAV
## 5 Flight Strategy Calculation Case
### The X Axis Open-Loop Slow Transition  
During longitudinal balancing and static moment balancing, the vertical grid of lift fan is not deflecting, and the \(X\)-axis limit is released, and the lift duct device is deflecting slowly with speed of 1 degree per second, in order to meet the transition terminal window speed of the UAV. The power and flight data are as shown in Figure 12:  
Similarly, during longitudinal balancing and static moment balancing, deflection angle of the vertical grid of lift fan is set to be 15 degree, the \(X\)-axis limit is released, and the lift duct device is slowly deflecting with rotating speed of 1\({}^{\circ}\)/s, until the UAV meets the speed of the transition terminal window. The power and flight data are as shown in Figure 13:  
Figure 11: Lift fan and lift duct state curve when pitch angle is 7.21\({}^{\circ}\).  
Figure 12: (**a**) Slow transition of lift fan and lift duct thrust state; (**b**) Slow transition of forward speed and lift duct deflection.  
The calculation results show that the slow deflection power device, regardless of the aircraft's dynamic characteristics, reduces the lift fan thrust gradually in 50 s. When the lift duct device deflects to a horizontal position, the aircraft speed gradually increases to the transition flight speed, reaching the transition terminal window and achieving stable and flat flight.  
By comparing the calculation results of the deflection angles of the two lift fan grilles in the transition process, it can be seen that the deflection of the lift fan longitudinal grille makes the UAV transition to the terminal window faster, but the lift fan required for longitudinal balance has higher thrust and power.