esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Conventional Frequency-Offset Estimation Method
### Conventional Scheme B  
In [29], a reduced-complexity CFO and SFO estimation is presented using the \(g\)-lag correlation, which is formulated as:  
\[\tilde{Y}_{g}(k)=\sum_{l=g+1}^{N_{b}}R_{l}(k)R_{l-g}^{*}(k),\;1\leq g<N_{b},\;k \in\mathcal{S}_{f}. \tag{12}\]  
With the aid of the \(g\)-lag correlations, \(\varphi(k)\) is estimated by:  
\[\hat{\varphi}(k)=\frac{1}{2\pi\beta}\sum_{g=1}^{N_{b}/2}w(g)\angle\left\{ \tilde{Y}_{g}(k)\tilde{Y}_{g-1}^{*}(k)\right\} \tag{13}\]  
where \(w(g)\) represents the weighing factor. The estimated CFO and SFO are given by:  
\[\hat{\varepsilon}=\frac{W(3)F(1)-W(2)F(2)}{W(1)W(3)-W^{2}(2)} \tag{14}\]  
and:  
\[\hat{\xi}=\frac{W(1)F(2)-W(2)F(1)}{W(1)W(3)-W^{2}(2)} \tag{15}\]  
where:  
\[W(n)=\frac{1}{N_{f}}\sum_{k\in\mathcal{S}_{f}}k^{n-1}|\tilde{H}_{l}(k)|^{2} \tag{16}\]  
and:  
\[F(n)=\frac{1}{N_{f}}\sum_{k\in\mathcal{S}_{f}}k^{n-1}|\tilde{H}_{l}(k)|^{2} \hat{\varphi}(k). \tag{17}\]  
Note that this low-complexity CFO and SFO estimator is presented in a decoupled way, which still demands heavy computational complexity.
## 4 Conclusions  
We have synthesized two new products that have aminophosphonic acid groups functionalized on a copolymer of acrylonitrile-15% divinylbenzene. The aminophosphonate groups (Bz-DVB-AN, Et-DVB-AN) grafted onto AN-DVB were synthesized following a \"one-pot\" Kabachnik-Fields reaction. The antibacterial evaluation of Bz-DVB-AN and Et-DVB-AN was tested in vitro against a species of Gram-negative bacteria (_E. coli_) and a type of Gram-positive bacteria (_S. aureus_). Aminophosphonates functionalized on AN-DVB have proven to be new antibacterial agents. It was proven that these compounds exhibit antibacterial activity. In these cases, the cells remaining after 18 h of treatment indicate that they are resistant. The first-order kinetic model and the Weibull model were used to model the kinetic inactivation of _S. aureus_ and _E. coli_ in Bz-DVB-AN and Et-DVB-AN. After 9 h of interaction, the Gram-positive bacterial load decreased by more than 50%, while the Gram-negative bacteria showed this effect only after 12 h. The samples are slightly more active against Gram-negative bacteria than against Gram-positive bacteria. The effectiveness of the Et-DVB-AN sample on _S. aureus_ varies from bacteriostatic (94.8%) to bactericidal (99%). It is observed that the rate of cell reduction for _S. aureus_ is quite quick.  
**Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/molecules29246054/s1](https://www.mdpi.com/article/10.3390/molecules29246054/s1)]([https://www.mdpi.com/article/10.3390/molecules29246054/s1](https://www.mdpi.com/article/10.3390/molecules29246054/s1)), Table S1: The total number of germs (CFU/mL) and percentage of bacterial reduction (P, %) at different contact times.  
**Author Contributions:** Coordination of the research project, A.P. and E.-S.D.; Coordination and carrying out the experimental works, M.V.D., E.-S.D., A.P., I.N., L.L. and A.V.; methodology, A.P. and I.N.; Products characterization and analysis, M.V.D., A.P., A.V., L.L. and I.N.; Formal analysis, A.P., L.L. and I.N.; Writing--original draft preparation, A.P., I.N., E.-S.D. and A.V.; writing--review and editing, A.P., A.V., I.N., L.L. and E.-S.D. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was partially supported by Program 2 of Romanian Academy, \"Coriolan Dragulescu\" Institute of Chemistry and by project \"ICT--Interdisciplinary Center for Smart Specialization in Chemical Biology (RO-OPENSCREEN)\", MySMIS code: 127952, Contract no. 371/20.07.2020, co-financed by the European Regional Development Fund under the Competitiveness Operational Program 2014-2020.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Data are contained within the article.  
**Conflicts of Interest:** The authors declare no conflicts of interest.
###### Abstract  
Consumers are increasingly interested in the geographical origin of foodstuff, as an important characteristic of food authenticity and quality. To assure the authenticity of the geographical origin, various methods have been proposed. Stable isotope analysis is a method that has been extensively used for products like wine, oil, and meat by using large datasets and analysis. On the other hand, only few studies have been conducted for the discrimination of seafood origin and especially for mullet roes or bottarga products, and even fewer investigate a small number of samples and datasets. Stable isotopes of Carbon (C), Nitrogen (N), and Sulfur (S) analysis of bottarga samples from four different origins were carried out. The first results show that the stable isotopes ratios of C, N, and S could be used to discriminate the Greek PDO Bottarga (Messolongi) from other similar products by using a probabilistic machine learning methodology. That could use limited sample data to fit/estimate their parameters, while, at the same time, being capable of describing accurately the population and discriminate individual samples regarding their origin.  
stable isotopes; food authenticity; probabilistic machine learning; PDO products +
Footnote †: journal: Applied Sciences
# Partial Pre-Emphasis for Pluggable 400 G Short-Reach Coherent Systems
###### Abstract  
Pre-emphasis filters are used to pre-compensate for the transmitter frequency response of coherent systems to mitigate receiver noise enhancement. This is particularly essential for low-cost, low-power coherent transceivers due to having an extremely bandlimited transmitter. However, the pre-emphasis filter also increases the signal peak-to-average power ratio (PAPR), thus posing a higher effective number of bits (ENoB) requirement for the arbitrary waveform generator (AWG). In this paper, we first numerically study the PAPR impact of partial pre-emphasis filters. We show that with partial pre-emphasis, an ENoB reduction from 5 to 4.5 bits is attainable at the same signal-to-noise ratio (SNR) out of the AWG. Next[PERSON] we experimentally investigate the overall performance penalty of partial pre-emphasis in a 50 Gbaud 16 QAM coherent system. A manageable Q factor penalty of around 0.5 dB is found for both single-polarization and dual-polarization systems with a 0.8 dB PAPR reduction.  
optical communications; pluggable transceivers; pre-emphasis; coherent communications
## 6 Conclusions  
In summary, the results of the conducted research allowed to establish the following conclusions:  
1. Review and modification of Port Regulations: Our findings suggest that by modifying the existing Port Regulations [36], it may be possible to reduce ship delays and financial losses, even at high traffic intensities. Policymakers should consider revisiting the current regulations and identify areas where adjustments could be made to minimize the impact of traffic intensity on ship delays.
2. Prioritization of oversize ships: Given that oversize ships with one direction of traffic account for a significant proportion of ship delays, policymakers should consider implementing strategies to prioritize the passage of these ships or establish dedicated time windows for their movement, thereby minimizing the disruption caused to other vessels on the waterway.
3. Infrastructure improvements: To accommodate the expected increase in larger vessels following the completion of the waterway deepening project, policymakers should invest in infrastructure improvements at the ports of Szczecin and Police, such as increasing berth capacity, enhancing port facilities, and improving navigational aids. These improvements will help to reduce delays and financial losses associated with larger ships.
4. Enhanced communication and coordination: Our study highlights the importance of effective communication and coordination between port authorities, shipping companies, and other stakeholders involved in the management of the Swinoujscie-Szczecin waterway. Policymakers should consider implementing measures to improve information sharing and real-time communication, enabling more efficient scheduling of ship movements and reducing the likelihood of delays.
* Monitoring and evaluation: To ensure the ongoing effectiveness of policies aimed at reducing ship delays and financial losses, policymakers should establish a robust monitoring and evaluation framework. This framework should involve the regular collection and analysis of data on ship delays, traffic intensity, and other relevant factors, allowing for the ongoing assessment of policy effectiveness and the identification of areas for further improvement.  
Conceptualization, LD. and L.G.; methodology, LD., L.G. and T.M.; formal analysis, LD. and T.M.; investigation, LD.; resources, LD, L.G. and T.M.; data curation, LD.; writing--original draft preparation, LD. and T.M.; writing--review and editing, L.G. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
Data Availability Statement: Data supporting reported results can obtained from Corresponding Author under email address: [EMAIL_ADDRESS].  
The authors declare no conflict of interest.
# Real-Time Penetration Recognition Based on Voltage Signal in K-TIG Welding
## 5 Conclusions  
Through an experimental investigation of austenitic 304 stainless steel, this study draws several conclusions based on the analysis of experimental results and verification outcomes.  
Firstly, an acquisition system is established to collect voltage and current signals during the welding process, and the welding signals are obtained through the docking welding experiments. A significant frequency spectrum segment is discovered at 36-37 kHz, which represents different welding melt states, including complete joint penetration and incomplete joint penetration states.  
Secondly, the characteristic signal strength of the 36-37 kHz frequency spectrum segment is significantly higher in the complete joint penetration state than in the incomplete joint penetration state. Furthermore, when the melt state has no observable changes, the characteristic signal strength remains relatively stable and does not change a lot due to changes in welding parameters. However, when the melt state changes in a visible manner from complete joint penetration to incomplete joint penetration, the characteristic signal strength will decrease observably.  
Thirdly, the characteristic signal strength will increase again to the initial complete joint penetration state's characteristic signal strength range by adjusting the compensation parameters to re-transform it into a complete joint penetration state when the welding changes from complete joint penetration to incomplete joint penetration.  
Based on these findings, this study proposes that the characteristic signal strength is only related to the melt state and does not change with changes in welding parameters. By monitoring the characteristic frequency spectrum signal and adjusting the welding parameters, the welding process can be maintained in a complete joint penetration state, thus achieving closed-loop control of welding melt quality. This approach may be beneficial in improving the consistency and stability of welding melt quality and enhancing the efficiency of welding production.  
Conceptualization, R.Y.; methodology, G.X.; software, H.B. and N.N.; validation, G.X. and H.B.; data curation, H.B.; writing--original draft preparation, H.B. writing--review and editing, N.N.; supervision, Y.W.; project administration, R.Y. and Y.W. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Data sharing not applicable.  
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
###### Abstract  
The complex problem of quantitative precipitation estimation in the Alpine region is tackled from four different points of view: (1) the modern MeteoSwiss network of automatic telemetered rain gauges (GAUGE); (2) the recently upgraded MeteoSwiss dual-polarization Doppler, ground-based weather radar network (RADAR); (3) a real-time merging of GAUGE and RADAR, implemented at MeteoSwiss, in which a technique based on co-kriging with external drift (CombiPrecip) is used; (4) spaceborne observations, acquired by the dual-wavelength precipitation radar on board the Global Precipitation Measuring (GPM) core satellite. There are obviously large differences in these sampling modes, which we have tried to minimize by integrating synchronous observations taken during the first 2 years of the GPM mission. The data comprises 327 \"wet\" overpasses of Switzerland, taken after the launch of GPM in February 2014. By comparing the GPM radar estimates with the MeteoSwiss products, a similar performance was found in terms of bias. On average (whole country, all days and seasons, both solid and liquid phases), underestimation is as large as \(-3.0\) (\(-3.4\)) dB with respect to RADAR (GAUGE). GPM is not suitable for assessing what product is the best in terms of average precipitation over the Alps. GPM can nevertheless be used to evaluate the dispersion of the error around the mean, which is a measure of the geographical distribution of the error inside the country. Using 221 rain-gauge sites, the result is clear both in terms of correlation and in terms of scatter (a robust, weighted measure of the dispersion of the multiplicative error around the mean). The best agreement was observed between GPM and CombiPrecip, and, next, between GPM and RADAR, whereas a larger disagreement was found between GPM and GAUGE. Hence, GPM confirms that, for precipitation mapping in the Alpine region, the best results are obtained by combining ground-based radar with rain-gauge measurements using a geostatistical approach. The GPM mission is adding significant new coverage to mountainous areas, especially in poorly instrumented parts of the world and at latitudes not previously covered by the Tropical Rainfall Measuring Mission (TRMM). According to this study, one could expect an underestimation of the precipitation product by the dual-frequency precipitation radar (DPR) also in other mountainous areas of the world.  
Global Precipitation Measurement; MeteoSwiss weather radar and rain-gauge networks; real-time radar-gauge merging; multi-sensor precipitation estimation 2017 9, 1147; doi:10.3390/rs9111147
## 3 Experiments and Discussion
### Experimental Datasets  
To evaluate the effectiveness of the model, three commonly used hyperspectral datasets--Indian Pines (IP), Pavia University (PU), and Salinas (SA)--were used to evaluate the FCGN algorithm in this paper.  
The IP dataset was acquired by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) sensor over the northwestern Indian region. This dataset contains 145 \(\times\) 145 pixels with 220 spectral bands ranging from 0.4 to 2.5 \(\upmu\)m. After removing 20 water absorption and noisy spectral bands, 200 bands were reserved for the experiment. The land cover scene consists of 16 classes with 10,366 labeled pixels. The dataset was divided into training, validation, and test sets. For this dataset, the sample size was relatively small, and the number of samples of each class was extremely unbalanced. Overall, 5%, 1%, and 94% of samples per class were randomly selected for training, validation, and testing, respectively, as presented in Table 1.  
The PU dataset was captured by the reflective optics system imaging spectrometer (ROSIS) sensor at Pavia University. This dataset contains 610 \(\times\) 340 pixels with 125 spectral bands ranging from 0.43 to 0.86 \(\upmu\)m. In total, 103 bands were utilized after discarding noisy bands. There are nine land cover categories in this dataset. Overall, 0.5%, 0.5%, and 99% of samples per class were selected for training, validation, and testing, respectively, as listed in Table 2.  
The SA dataset is another commonly used dataset for hyperspectral image classification. It was recorded by the AVIRIS sensor over the Salinas Valley. This dataset contains 512 \(\times\) 217 pixels with 224 spectral bands, and 204 bands were utilized. There are 16 land cover categories in this dataset. Because this dataset has a larger number of samples compared with Indian Pines, 0.5% of the labeled samples were selected as the training set and the validation set, and 99% of samples per class were randomly selected for testing, as listed in Table 3.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**NO.** & **CLASS** & **Train** & **Val** & **Test** \\ \hline
1 & Apshalt & 34 & 34 & 6563 \\
2 & Meadows & 94 & 94 & 18,461 \\
3 & Gravel & 11 & 11 & 2077 \\
4 & Trees/Grass & 16 & 16 & 3032 \\
5 & Metalsheets & 7 & 7 & 1331 \\
6 & Baresoil & 26 & 26 & 4977 \\
7 & Bitumen & 7 & 7 & 1316 \\
8 & Bricks & 19 & 19 & 3644 \\
9 & Shadows & 5 & 5 & 937 \\ \hline \hline  & Total & 219 & 219 & 42,338 \\ \hline \end{tabular}
\end{table}
Table 2: The dataset division for each class of the PU dataset.
## 6 Discussion  
This paper proposes a surface electromyography (sEMG) feature-extraction method based on spatial expansion to improve gesture recognition accuracy. The innovation lies in introducing the \"Space-to-Space (SPS)\" framework, which folds the signals in the time dimension to expand the original sEMG data points in the spatial dimension, releasing more feature information within a single channel. On the SPS processed signals, time-domain features (including RMS, MAV, SSC, WL, ZC, etc.), frequency-domain features (using wavelet transform), and spatial features (ICC matrix constructed from inter-channel covariance matrix) are extracted to achieve multi-dimensional feature fusion. The experimental results demonstrate that compared to using only time-domain and frequency-domain features, this method achieves significant recognition performance improvements of 2.04% to 4.93% in average accuracy on the Ninapro DB4, DB5, BioPatRec DB1-DB3, and Mendeley Data datasets. This clearly shows that spatial features play a key role in sEMG decoding. In addition, comparative analysis with other state-of-the-art methods also proves the superiority of this method in terms of higher gesture recognition accuracy.  
While adopting the multi-view feature fusion strategy enriches the feature expression of sEMG signals and improves gesture recognition accuracy, different classifiers demonstrate varying sensitivities towards features. For instance, the SVM classifier is more sensitive to frequency-domain features and can achieve higher accuracy using only frequency-domain features, but struggles in handling multi-dimensional features. In contrast, the LDA classifier is more sensitive to time-domain features and performs well in both individual time-domain features and combinations of time-frequency-domain features, yet has weaker capabilities in dealing with multi-dimensional features. Overall, this article has made useful explorations in the expression and fusion of multi-view sEMG features, which provides a reference for the selection of classifiers and feature-extraction methods in practical applications, and provides new ideas for surface electromyographic signal analysis.
# Terahertz Raman Measurements Using a Spatial Heterodyne Raman Spectrometer
## 5 Conclusions  
We have proposed a spatial heterodyne THz Raman spectrometer based on field widening. The system includes 532 nm BNFs for selective filtering of Raman scattering light, two field-widening prisms with an apex angle of 2.665\({}^{\circ}\) on the interference arms, and 150 gr/mm gratings.  
We measured the THz Raman spectra of sulfur, organic acids, RNA nucleobases, and aqueous solutions. In addition, we measured solid and liquid mixtures. The results show that the system can effectively distinguish the components of a mixture. The calculated SNRs of sulfur samples under different integration times and laser powers show that the system has good stability, and the SNR reaches approximately 750 at a low laser power of 60 mW with a short integration time of 20 s. We measured 2-hydroxy BA at different times under the same integration time and laser power. The positions and intensities of Raman peaks were almost the same, which proved that the system had good repeatability. To test the influence of the container, we measured the THz Raman spectra of a sample in containers of different thicknesses and materials. The results show that the spectral resolution is not significantly affected by the selection of different containers. The spatial heterodyne THz Raman spectrometer system has no incident slit, which effectively improves the throughput. The system has good stability and repeatability, and realizes signal measurement of aqueous solutions in the THz band. It can be applied in such fields as material detection, environmental protection, medicine, and marine exploration.  
Conceptualization, X.L. and Y.S.; methodology, Y.S.; software, Z.L.; validation, Y.S. and X.L.; formal analysis, X.M.; investigation, Q.C.; resources, J.G.; data curation, J.C.; writing--original draft preparation, Y.S.; writing--review and editing, Y.S.; visualization, X.Y. and P.L.; supervision, X.L. All authors have read and agreed to the published version of the manuscript.  
National Natural Science Foundation of China (61975255, U2006209, 61505204), Jilin Province Research Projects in China (20190302047 GX, 20200404197 YY, 2020 SYHZ0040).  
Not applicable.  
The authors declare no conflict of interest.