esa-sceva/satcom-chunk-collection huggingface dataset:
# Graphene-Based Flexible Electrode for Electrocardiogram Signal Monitoring
## 2 Research on Graphene-Based Flexible ECG Electrodes
### Laser-Induced/Scribed Graphene ECG Electrodes
#### 2.4.4 Stretchable LIG ECG Electrode  
Usually, LIG is fabricated and instrumented simultaneously on PI substrate. This method is very simple and efficient, and the resulting LIG electrode has good electrical conductivity. However, due to the limited flexibility of the PI substrate [66], the LIG electrode can only bend with the PI substrate, not stretch freely. This greatly limits the use of LIG electrodes because, as the surface of the human body is soft, uneven, and movable, it is difficult for the PI substrate to merge and move tightly with the skin. This situation further affects comfort and the quality of collected ECG signals. To solve the disadvantages of the PI substrate while retaining the excellent ECG monitoring performance of the LIG. [PERSON] et al. proposed a stretchable LIG ECG electrode by replicating the LIG patterns with ultrathin and highly flexible polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS), packaged into a highly stretchable layer-by-layer structure [67]. As shown in Figure 3c, the LIG was first produced by a 10.6 \(\upmu\)m CO\({}_{2}\) laser on a PI film. Then, 3,4-ethylene dioxythiophene (EDOT) was assembled on MXene-Ti\({}_{3}\)C\({}_{2}\) to give the LIGelectrode temperature- and strain-sensing ability, improve its conductivity, and enhance its viscosity with SEBS to facilitate LIG transfer and packaging. Furthermore, an MXene-Ti\({}_{3}\)C\({}_{2}\)@EDOT layer was transferred onto the LIG by electrophoretic deposition. Finally, the MXene-LIG layer was replicated from the PI substrate to the SEBS and encapsulated. The resulted high flexibility and high conductivity electrode cannot only detect ECG signals but can also monitor temperature and motion. When monitoring ECG signals, the MXene-LIG electrode realizes significantly lower contact impedance (51.08 k\(\Omega\) at 10 Hz) than the commercial Ag/AgCl gel electrode, enabling high-quality detection of ECG signals. Moreover, the stable and highly flexible electrode realizes a higher signal-to-noise ratio during long-term and real-time ECG monitoring, which provides a promising development direction for graphene ECG electrodes.
# Sensitivity Analysis of P-Wave Polarization Direction and Velocity Gradient Inversion
## 5 Tests and Discussion
### The Effect of Improving Inversion Results
Figure 6: Enlarged image within the red dashed box in Figure 5. (**a**) An enlarge view of the dashed box labeled 1 in Figure 5; (**b**) An enlarged view of the dashed box labeled 2 in Figure 5; (**c**) An enlarged view of the dashed box labeled 3 in Figure 5; (**d**) An enlarged view of the dashed box labeled 4 in Figure 5; (**e**) An enlarged view of the dashed box labeled 5 in Figure 5; (**f**) An enlarged view of the dashed box labeled 6 in Figure 2:0  
Figure 8 illustrates the variation of the error between the true relative velocity gradient values and those obtained using two different inversion methods, as the number of iterations increases. As seen in Figure 8, our proposed method exhibits a faster convergence rate compared to the ART method when the error values are equal. Additionally, our proposed method achieves lower error values than the ART method, highlighting the proposed method's superior accuracy and efficiency in estimating relative velocity gradients. This improved performance can be attributed to the inclusion of an adjustment factor in our method, which effectively minimizes the error and provides more accurate estimates of the relative velocity gradients. This underscores the superior efficiency and reliability of our proposed method in solving the inverse problem associated with the estimation of relative velocity gradients. We conducted a quantitative analysis of the quality of gradient maps obtained using two methods through commonly used image evaluation metrics. Specifically, we calculated the Pearson Linear Correlation Coefficient (PLCC) and the Mean Squared Error (MSE) between the true gradient maps in the range of 0 m to 37.5 m near the source and the gradient maps generated by the two methods [33]. The PLCC measures the linear correlation of pixel value variations between the reconstructed image and the original image, with a value range of [\(-\)1, 1]. A PLCC value close to 1 indicates a high level of consistency in pixel value changes between the reconstructed image and the true gradient map. MSE is  
Figure 2:1 The relationship curve of error with the number of iterations. Figure 2:2 Comparison of vertical slices of inversion results at 25 m.  
an indicator used to measure the difference between two images. A smaller value of MSE indicates that the difference between the reconstructed image and the original image is smaller, indicating better quality of the reconstructed image. Conversely, a larger value of MSE indicates a greater difference between the reconstructed image and the original image, indicating poorer quality of the reconstructed image. As shown in Table 1, the PLCC and MSE of the gradient maps obtained using our proposed method are better than those of the gradient maps obtained using ART methods. These quantitative data suggest that the gradient maps obtained based on our method exhibit high quality, providing more accurate foundational data for subsequent image processing and analysis.
# Frequency Comb-Based WDM Transmission Systems Enabling Joint Signal Processing
## 2 Comb-Based Superchannels
### Superchannel Transmitter Requirements  
In this subsection, we will discuss the requirements of comb-based versus discrete laser array-based light sources for superchannel generation. We first focus on how the required OSNR (OSNR refers to the noise power within a bandwidth of 0.1 nm throughout this paper) translates into varying comb requirements. This is followed by a discussion on inter-channel guard bands and the role of frequency combs in enabling ultra-dense WDM.
## 2 Materials and Methods  
### Application of rhGDF-5  
rhGDF-5 was topically applied, embedded in an innovative collagen-gelatin matrix (developed in cooperation with Freudenberg New Technologies KG, Weinheim, Germany and Biopharm GmbH, Heidelberg, Germany). The scaffold is based on a compound from animal derived collagen and gelatin produced with a novel standardized spinning procedure. The gelatin and collagen were processed into fibers with rhGDF-5 by rotation spinning. Briefly, by spinning the rotor and cooling the material, liquid jets of the precursor solution transitioned from a solution to a gel and completely solidified during flight. During this process, the liquid jet of the precursor solution became desiccated, which resulted in the formation of stable fibers with all the components homogeneously distributed. Secondly, these fibers were deposited as a composite biomaterial. This final fiber biomaterial was bioresorbable, nonwoven, non-crosslinked, and consisted of fibers with a bimodal distribution between 2 and 10 \(\upmu\)m in diameter and pore sizes between 35 and 70 \(\upmu\)m.  
The collagen-gelatin scaffold was made with various surface densities: 30 g/m\({}^{2}\), 75 g/m\({}^{2}\), 90 g/m\({}^{2}\) and 150 g/m\({}^{2}\). rhGDF-5 was obtained via expression in _Escherichia coli_ (strain W3110 BP) and, after isolation, was added to the collagen-gelatin scaffold at various concentrations: 100 ng/m\({}^{2}\), 500 ng/m\({}^{2}\), 1000 ng/m\({}^{2}\), and 5000 ng/m\({}^{2}\). The composite biomaterial was applied on the first day of the study for the single-application groups, only being applied once, and the multiple-application groups, which were refreshed every second day. These groups were then compared to untreated wounds and wounds treated with the commercially available collagen-elastin matrix according to the manufacturer's instructions. It is of bovine origin and consists of a three-dimensional, native, structurally intact collagen matrix, which is a combination of collagen types I, III, and V coated with a freeze-dried, non-crosslinked \(\alpha\)-elastin hydrolysate that has an open-pore structure.
## 2 Takagi-Sugeno Fuzzy Modeling of DC-DC Converters
### T-S Fuzzy Model of a Boost Converter  
Figure 3 shows the schematic of a boost converter. As in the previous section, the converter operates in CCM and parasitic resistances in the inductor and the capacitor are sufficiently small to be neglected.  
Figure 3: Schematic circuit of a boost converter.  
Figure 2: T-S Fuzzy representation of the buck-boost converter.  
The incremental bilinear model of the boost converter has the form presented in (1). The values of vectors and state space matrices are written as follows:  
\[\tilde{x}(t)=\left[\begin{array}{c}\tilde{l}_{L}\\ \tilde{v}_{C}\end{array}\right]\quad X=\left[\begin{array}{c}\frac{V_{x}}{ \mathcal{D}^{\prime}}\\ \frac{V_{y}}{\mathcal{D}^{\prime}}\end{array}\right]\quad\tilde{u}(t)=\left[ \tilde{d}(t)\right]\quad\tilde{w}(t)=\left[\tilde{i}_{o}(t)\right]\quad\tilde{ z}(t)=\left[\tilde{v}_{C}(t)\right]\]  
\[A=\left[\begin{array}{cc}0&-\frac{D^{\prime}}{L}\\ \frac{D^{\prime}}{C}&-\frac{1}{RC}\end{array}\right]\quad B_{u}(\tilde{x})= \left[\begin{array}{c}\frac{V_{x}}{D^{\prime}L}+\frac{\tilde{v}_{C}(t)}{L}\\ -\frac{V_{y}}{D^{2}RC}-\frac{l_{i}(t)}{C}\end{array}\right]\quad B_{w}=\left[ \begin{array}{c}0\\ -\frac{1}{C}\end{array}\right] \tag{13}\]  
\[C_{z}=\left[\begin{array}{cc}0&1\end{array}\right]\quad D_{zw}=\left[0 \right]\quad D_{zu}=\left[0\right]\]  
Applying the methodology of the previous section, the T-S fuzzy model of the boost converter can be expressed as:  
\[\tilde{x}(t)=\left[\begin{array}{cc}0&-\frac{D^{\prime}}{L}\\ \frac{D^{\prime}}{C}&-\frac{1}{RC}\end{array}\right]\tilde{x}(t)+h_{1}\left[ \begin{array}{c}\frac{V_{x}}{D^{\prime}L}+\frac{v_{C_{min}}}{L}\\ -\frac{V_{x}}{(D^{2}R)C}-\frac{l_{i_{max}}}{C}\end{array}\right]+h_{2}\left[ \begin{array}{c}\frac{V_{x}}{D^{\prime}L}+\frac{v_{C_{min}}}{L}\\ -\frac{V_{y}}{(D^{2}R)C}-\frac{l_{i_{max}}}{C}\end{array}\right]\]  
where the weight contribution of each fuzzy rule \(\{h_{1},\ldots,h_{4}\}\), have the same behavior as for the buck-boost converter case (12).  
In the next section, the proposed LMI-fuzzy control strategy is explained. This control law consists of a weighted sum of the feedback gains of each submodel, which has constraints such as: perturbation rejection level, decay rate of state variables and control effort.
###### Abstract  
This study sought to test the feasibility of a newly developed plane called computed modified absolute mandibular midsagittal plane (cmAMP) based on the similarity index (SI) for evaluating the stereoscopical symmetry of the mandible by comparison with other proposed midsagittal planes. This study involved 29 adult patients (15 men, 14 women; average age, \(23.1\pm 6.9\) years) with skeletal Class III facial asymmetry who underwent bimaxillary orthognathic surgery. Using cone-beam computed tomography images taken before and 1 year after surgery, cmAMP with the highest SI value between the two anterior segments of the hemi-mandible was set by a computer algorithm. Results show that the SI using cmAMP had the highest value (\(0.83\pm 0.04\)) before surgery compared to the other midsagittal planes, and was not significantly different from the SI (\(0.80\pm 0.05\)) using a facial midsagittal plane (MSP) after surgery. The distance (\(1.15\pm 0.74\) mm) and angle (\(2.02\pm 0.82^{\circ}\)) between MSP and cmAMP after surgery were significantly smaller than those between MSP and other midsagittal planes. In conclusion, the cmAMP plane best matches the two anterior segments of hemi-mandible symmetrically and is the closest to MSP after orthognathic surgery in skeletal Class III patients with facial asymmetry.  
Keywords:similarity index; facial asymmetry; computed modified absolute mandibular midsagittal plane; mental foramen; computer algorithm +
Footnote †: journal: Applied Sciences
# Monthly Analysis of Wetlands Dynamics Using Remote Sensing Data
## Materials and Methods  
### Study Area  
Sakarya River is the third longest river in Turkey and is 824 km length, while Balikdami is one of the wetlands formed along Sakarya riverbed. Located in the central Anatolian part in Turkey, Balikdami is a unique wetland containing rich flora and fauna and more than 256 bird species. This area is one of Turkey's few wetlands, and it is one of the most important accommodation points for birds that migrate seasonally between northern and southern countries. The reed areas in Balikdami are used as a shelter and breeding area for many birds.  
The central Anatolian region has natural vegetation cover that starts forming after a harsh winter. The vegetation cover starts drying in the summer season due to lack of rainfalls. It should be noted that in the study area, the leaf-on season starts in April and ends before November, while the leaf-off season is between November and March.  
According to the yearly hydro-meteorological reports, the rainfalls in the Anatolian region in the 2017 winter season, has been slightly below the average amount, while the highest average temperature has been reported in the summer period, in July, with 26 \({}^{\circ}\)C.  
The study area has been visited for inspection in April 2017. However, since the bigger part of the wetland was inaccessible, it was decided to collect high-resolution optical data from an Unmanned Aerial Vehicle (UAV), and afterward to determine the classes with a wetland expert.
# BDS Satellite Clock Prediction Considering Periodic Variations
## 5 Conclusions  
Due to space environment changes, temperature variations, and various disturbances, the periodic noise of the BDS satellite clocks is time-varying. In this paper, the periodic variations of BDS satellite clock offsets are analyzed by STFT. Then, the time-varying periodic terms are used to improve the performance of the clock prediction. Some conclusions can be summarized from this paper:  
1. Both the amplitude and frequency of periodic terms in clock offsets vary with time for all BDS satellites discussed in this paper.
2. For satellites with marked periodic variations, the fitting accuracy of TFAM is significantly improved. Compared with SAM, the mean RMS of the TFAM fitting residuals increases by 10.5% for WHU clock offsets and 12.2% for GFZ clock offsets.
3. TFAM can improve the average prediction accuracy of the SAM. Compared with SAM, the improvement rate of the prediction accuracy using TFAM of the 6 h, 12 h, 18 h and 24 h is in the range of 6.4% to 10% for WHU clock offsets, while 11.1% to 14.4% for GFZ clock offsets.
4. Compared with SAM, for C06, C14, and C32 with marked periodic variations, the prediction accuracy using TFAM is improved by 26.7%, 16.2%, and 16.3% for WHU clock offsets, and 29.8%, 16.0%, 21.0%, and 9.0% of C06, C14, C28, and C32 for GFZ clock offsets.  
Conceptualization, L.Z., H.L. and N.L.; methodology, L.Z., H.L.; validation, N.L., R.W. and M.L.; formal analysis, H.L. and R.W.; investigation, N.L.; resources, L.Z. and H.L.; data curation, N.L. and M.L.; writing--original draft preparation, N.L.; writing--review and editing, H.L. and N.L.; visualization, N.L. and R.W.; supervision, L.Z. and H.L.; project administration, H.L. 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 (Nos. 61773132, 61803115), the China Postdoctoral Science Foundation (No. 2020M681078), the Qingdao Postdoctoral Foundation (No. QDBSHYYYJXM20200101), Shandong Province Postdoctoral Innovation Project (No. 202003050), and the Fundamental Research Funds for Central Universities (No. 3072021 CFJ0404).  
Not applicable.  
The data supporting this research can be found at the hyperlinks as: [[https://cddis.nasa.gov/archive/gnss/products/mgex](https://cddis.nasa.gov/archive/gnss/products/mgex)]([https://cddis.nasa.gov/archive/gnss/products/mgex](https://cddis.nasa.gov/archive/gnss/products/mgex)), accessed on 14 August 2021.  
The authors acknowledge the GNSS Research Center of Wuhan University and the Geo Forschungs Zentrum for providing the data.  
The authors declare no conflict of interest.
# An Insight into the Chemistry of Cement--A Review
## 3 Hydration Step Involving OPC
### Mechanism and Heat of Hydration of OPC
#### 3.3.3 Acceleration Period  
During this step, hydration accelerates once again. The C\({}_{3}\)S hydration favors the formation of the \"outer\" C-S-H, which is different from the \"inner\" C-S-H. [PERSON] et al. [76] proposed a model describing the formation of calcium silicate hydrate, making a distinction between low-density (LD) C-S-H (\"outer\" product), and high-density (HD) C-S-H (\"inner\" product). Figure 4 shows a C\({}_{3}\)S grain after 96 h of hydration, where both C-S-H products are present [77]. In particular, the \"outer\" C-S-H forms during the early hydration step. It is easily recognizable as it remains away from the cement particle surface, and it is highly porous. On the other hand, the \"inner\" C-S-H forms during the late hydration step, and it has low porosity. Furthermore, the amount of \"inner\" C-S-H increases as the \(w/c\) ratio decreases [78].  
During this step, a noticeable hydration of C\({}_{2}\)S is also registered. Moreover, Portlandite (i.e., CH) precipitates from the liquid, thus decreasing the amount of Ca\({}^{2+}\) ions in the liquid. Gypsum, instead, completely dissolves. Quite surprisingly, the concentration of SO\({}_{4}\)\({}^{2-}\) anions in the liquid decreases, probably because of the occurrence of two phenomena: (i) the formation of the AFt phase, and (ii) the adsorption of SO\({}_{4}\)\({}^{2-}\) ions at the surface of the C-S-H phase.
## 4 Results and Discussion
#### 4.1.2 Barrier Heights for Different Tops
top axes C\({}_{3}\)-C\({}_{14}\), C\({}_{17}\)-C\({}_{19}\) and C\({}_{19}\)-O\({}_{19}\) have two-fold barriers (Figure S1a-c). The barrier heights for the forward and reverse transitions A/E \(\rightarrow\) C for the three rotations were found to be 2.301/2.710, 6.013/2.606 and 20.565/20.565 and 1.544/1.945, 6.395/2.988 and 11.340 kcal/mol, respectively. Referring to Figure S1b, the point A corresponds to the situation when the OH group of the carboxylic moiety faces towards the N-atom, while the point C corresponds to the situation when the carbonyl O atom faces towards the N atom. The barrier height for the transition A \(\rightarrow\) C during which the H atom of the OH group passes through the space closer to the phenyl ring is much higher (6.013 kcal/mol) than that when the H atom of the OH group passes through the space farther from the phenyl ring (2.606 kcal/mol). The rotation about the top axis C\({}_{14}\)-C\({}_{17}\) has a three-fold potential barrier (Figure S1d). It has a very shallow minimum (point E), with the energy 0.123 kcal/mol for the transition E \(\rightarrow\) C and 2-10 kcal/mol for the transitions A \(\rightarrow\) C.  
The rotation of the NH\({}_{2}\) group in different orientations of the neighboring carboxylic group has a two-fold barrier (Figure S1e). The scan curve for the rotation of the NH\({}_{2}\) group when the H\({}_{24}\) atom of the COOH group faces towards the NH\({}_{2}\) group is shown in Figure S1e. The local minima points A/C correspond to the configuration when the NH\({}_{2}\) group is directed away from/faces towards the H\({}_{24}\) atom of the carboxylic group. The barrier heights for the forward and reverse transitions A/E \(\rightarrow\) C via the points B/D are 17.103 and 18.986 compared to 7.336 and 9.219 kcal/mol.
# Fiber Monitoring System Applied to Railway Bridge Structures in a Near-Fault Region
## 3 Research Design and Data Collection
### System Framework for Data Collection  
A DFOS system was set up near the testing ground of the Taiwan High-Speed Rail box girder bridge in Yanchao, Kaohsiung City (Figure 7). The DFOS system includes the function of Brillouin Optical Time Domain Analysis (BOTDA: NBX-6066, Neubrex Co., Ltd. Sakaemachidori 1-1-24, Chuo-ku, Kobe, Hyogo, 650-0023 Japan). BOTDA utilizes Brillouin scattering to measure Brillouin gain and loss when light travels through a fiber. BOTDA was set to measure 1 km with a spatial resolution of 5 cm, a measurement accuracy of 7 \(\mu\epsilon\), repeatability of 3 \(\mu\epsilon\), and a frequency of measurement that could be set from  
Figure 6: (**a**) Sensing fiber imbedded with steel wires. (**b**) Fiber location on the box girder. (**c**) Cross-section of an installed sensing fiber.  
10 to 60 min. The system includes a server for large data storage and internet connection. A computer was used for numerical calculation with high-speed data processing and a software platform with GUI for data fetching and graphical presentation.  
The server first sends a command through LAN/WAN to BOTDA to start fiber measurement. BOTDA starts sending signals through sensing fiber, and the fiber backscatters the signal back to BOTDA. BOTDA records the data and sends it to the server for further data analysis. The data are processed through a dedicated high-speed computer, and the server stores the processed data. The processed data can then be accessed through software and presented graphically. The alarm and warning values can be set, and if the measured data exceed these values, warning messages can be sent. Users of the system can also access data via PC, tablet, or phone using the internet to increase data availability when not stationed near the server. A UPS system is also included in case of an emergency. Earthquakes and typhoons are a regular occurrence in Taiwan, and unfortunately, electricity will go out on some occasions. Bridges are most at risk in these dire situations; thus, a UPS system is needed for sending alarms in case of an emergency.