esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Simulation of Underwater Electric Field Communication
### Analysis of Underwater Electric Field Communication Simulation Results
#### 3.2.2 Underwater Electric Field Communication Packet Delivery Rate Simulation Test  
The underwater electric field was evaluated by using the packet delivery ratio to assess the stability of data transmission in underwater CSMA/CA channel communication. The packet delivery ratio is a rate that measures the proportion of data packets sent and received in a network. In an ideal situation, as many data packets are sent, an equal number of packets should be received. However, due to factors such as signal attenuation and network quality in underwater electric field communication, the ideal scenario does not always occur. The packet delivery ratio is mainly influenced by network traffic and congestion levels in each routing segment from the computer to the website server. Since TCP/IP networks can automatically implement retransmission, packet loss can result in even more packet loss. Therefore, it is common to observe an increasing packet loss rate after network congestion occurs [31; 32].  
The packet delivery rate is calculated by the upper layer of the routing layer during data transmission. It represents the ratio between the total number of received packets and the total number of sent packets in the network. This ratio indicates the probability of successful packet delivery in the entire multi-node communication network, as well as the packet loss rate due to link failures during the transmission process. In the simulation of multi-node communication in underwater electric fields, this parameter can effectively reflect the efficiency of the routing protocol in transmitting data between nodes, and the Formula (11) defines this parameter. In this simulation scenario, two protocols (OLSR and ADOV) were applied to five nodes within 10 s. The results of the packet delivery rates of the two routing protocols under the CSMA/CA channel are shown in Figure 6.  
\[Packet\_ratio=\frac{d_{Tx}}{d_{Rx}} \tag{11}\]  
where \(Packet\_ratio\) represents the packet delivery rate, \(d_{Tx}\) represents the total number of received packets, and \(d_{Rx}\) represents the total number of sent packets.  
The simulation results show that in the communication process, OLSR had a higher packet reception rate and higher data transmission reliability compared to the AODV routing protocol when five nodes were used. Therefore, in future underwater field communication, it is recommended to use the OLSR routing protocol based on the CSMA/CA  
Figure 6: Comparison analysis of packet delivery rate in underwater electric field communication under different protocols.  
channel for multi-node communication. This can improve the stability of signal transmission between nodes and ensure effective underwater multi-node operations.
## 3 Results and Discussion
### Antibacterial Activity  
Antibacterial activity of cauliflower, broccoli, red cabbage, white cabbage and Chinese cabbage extracts against two bacterial strains, i.e., _Bacillus cereus_ (Gram positive) and _Escherichia coli_ (Gram negative) is presented in Table 4. All the _Brassica_ species exhibited moderate antibacterial activity (Figure 3). All the extracts showed higher activity against the _B. cereus_ strain. Red cabbage extract showed the highest activity against _B. cereus_ (16.3 mm) followed by cauliflower (15.0 mm) and broccoli (14.4 mm). In the positive control, gentamicin showed highest activity of the extracts (18.1 mm), against _E. coli_, white cabbage extract showed highest activity, i.e., 14.4 mm, and broccoli showed the least. Our results are comparable with the published reports that explained that red cabbage extract showed good antibacterial activity [27; 28].  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Extracts**} & \multicolumn{2}{c}{**Inhibition Zone (mm)**} \\ \cline{2-3}  & _Bacillus cereus_ & _Escherichia coli_ \\ \hline Cauliflower & 15.0 \(\pm\) 0.55 \({}^{\rm c}\) & 6.0 \(\pm\) 0.31 \({}^{\rm a}\) \\ Broccoli & 14.4 \(\pm\) 0.51 \({}^{\rm c}\) & \textless{}6 \(\pm\) 0.21 \({}^{\rm a}\) \\ Red Cabbage & 16.3 \(\pm\) 0.71 \({}^{\rm c}\).d & 12.3 \(\pm\) 0.42 \({}^{\rm c}\) \\ White Cabbage & 10.5 \(\pm\) 0.22 \({}^{\rm b}\) & 14.4 \(\pm\) 0.55 \({}^{\rm d}\) \\ Chinese Cabbage & 8.23 \(\pm\) 0.31 \({}^{\rm a}\) & 12.7 \(\pm\) 0.41 \({}^{\rm c}\) \\ Gentamicin & 18.1 \(\pm\) 0.91 \({}^{\rm d}\) & 9.21 \(\pm\) 0.25 \({}^{\rm b}\) \\ \hline \hline \end{tabular}  
* The values are mean \(\pm\) standard deviation of three independent observations. Different letters in superscript show significant differences among selected _Brassica_ species.  
\end{table}
Table 4: Antibacterial activity of ethanolic extracts of selected species of _Brassica_.  
Figure 3: Typical plates showing the inhibition zones of ethanol extract of selected _Brassica_ species.  
Figure 2: Reducing power of ethanol extract of selected _Brassica_ species.
# Applying Deep Learning to Medical Imaging: A Review
## 4 Deep Learning for Specific Medical Imaging Modalities
### Ultrasound Imaging
#### 4.4.1 DL Techniques and Applications to Ultrasound  
CNNs have been widely used in ultrasound image analysis tasks. For example, U-Net [6] has been used for segmentation of the fetal brain in ultrasound images [153]. Moreover, RNNs have been used for tracking the fetal brain in ultrasound videos [154]. Additionally, DL techniques have been applied to ultrasound elastography for tissue characterization [155].
# Compact Multilayer Yagi-Uda Based Antenna for IoT/5G Sensors
###### Abstract  
To increase the capacity and performance of communication systems, the new generation of mobile communications (5G) will use frequency bands in the mmWave region, where new challenges arise. These challenges can be partially overcome by using higher gain antennas, Multiple-Input Multiple-Output (MIMO), or beamforming techniques. Yagi-Uda antennas combine high gain with low cost and reduced size, and might result in compact and efficient antennas to be used in Internet of Things (IoT) sensors. The design of a compact multilayer Yagi for IoT sensors is presented, operating at 24 GHz, and a comparative analysis with a planar printed version is shown. The stacked prototype reveals an improvement of the antenna's main properties, achieving 10.9 dBi, 2 dBi more than the planar structure. In addition, the multilayer antenna shows larger bandwidth than the planar; 6.9 GHz compared with 4.42 GHz. The analysis conducted acknowledges the huge potential of these stacked structures for IoT applications, as an alternative to planar implementations.  
Yagi-Uda; multilayered antenna; millimeter-waves; IoT +
Footnote †: journal: Sensors
# Hermite Quartic Splines for Smoothing and Sampling a Roughing Curvilinear Spiral Toolpath
## 3 Toolpath Quality Evaluation  
As shown in many research works, notably in [13; 14], discontinuities in the tangency and curvature of the toolpath geometry challenge the limited acceleration and jerk of each axis of the numerically controlled machine tool. Therefore, the average speed rate is always lower than the programmed one, and the milling time is longer than expected.  
Here, a double objective is pursued: increasing the speed along the toolpath (which can reduce milling time) and mastering the position of the tool along the milling path. For the tool speed evaluation, two methods are employed:  
* A local approach: VPOp.
* A global approach: Toolpath absolute curvature value.  
Figure 6: Building the curvilinear spiral between 2 isotherms.  
VPOp (Velocity Profile Optimization--version 2.6) is licensed software developed by [PERSON] and et al. [33]. Based on kinematic data and the CNC parameters of a given machine tool, it generates optimized feedrate planning that respects the capabilities of the milling center and thus predicts the actual tool speed and slowdowns for the tool. So, the modelized milling time is close to the real one. VPOp is used locally to analyze the velocity profile along two turns of the curvilinear spiral.  
To analyze the entire trajectory, histograms of the toolpath absolute curvature value (\(|C|\) in mm\({}^{-1}\)) are used as well as 95% and 99% quantiles of \(|C|\) named **Cut95** and **Cut99**. These last indicators can quickly give, unlike VPOp, the geometrical quality of a toolpath and, consequently, the possibility of NC to respect the programmed feed rate.  
A comparison will be made between the \"no fitted\" toolpath (called **RAW**) and the fitted one with HQS method (called **HQS**). For another comparison point for milling time, a filtered toolpath is also computed, called **FIR**, and corresponding to a moving average on three points applied twenty times (this combination gives results close to the HQS method). Note that the more the filter is applied, the smoother the trajectory but the more the position control is lost. So, the FIR toolpath is absolutely not suitable to satisfy our goal.
## 2 Determining Vehicle Position
### Position from ART flags
#### 2.2.6 Calculation of the Position and Orientation of the Marker  
The proposed equation for a calibrated camera can be written as follows  
\[\lambda[u,v,1]=K[R|t][X,Y,Z,1]^{\mathrm{T}}, \tag{5}\]  
where \(K\) is the matrix of the internal camera parameters containing the focal length and the physical centre of the image, matrix \([R|t]\) is the matrix of the external camera parameters containing rotations and translations of the camera coordinate system relative to global coordinate system. The task is to calculate matrix \(Q\) from the linear equation \(Q\times H=0\), where \(H=K[R|t]\). Using the homogeneity of the image points \(p_{i}\) the equations could be written as, \(P_{i}^{\mathrm{T}}h_{i}^{\mathrm{T}}+0\times h_{2}^{\mathrm{T}}-u_{i}P_{i}^{ \mathrm{T}}h_{3}^{\mathrm{T}}=0\) and \(0\times h_{1}^{\mathrm{T}}+P_{i}^{\mathrm{T}}h_{2}^{\mathrm{T}}-v_{i}P_{i}^{ \mathrm{T}}h_{3}^{\mathrm{T}}=0\), where \(h_{i},i=1,\ 2,\ 3\) are rows of the unknown matrix \(H\). To obtain the matrix \(H\), the Singular Value Decomposition (SVD) method shall be used. At least four \(p\) points on the image \(I\) and their equivalents in 3D are needed to solve the equation. As a result of calculating SVD one of the matrices is the matrix \([R|t]\), where \(t=[x,y,z]\), from which we will determine the distance between the vehicle and the marker \(d_{v}=\lambda\sqrt{x^{2}+y^{2}+z^{2}}\).
# Detecting Criticality by Exploring the Acoustic Activity in Terms of the \"Natural-Time\" Concept
## 4 Discussion and Conclusions
The specific time instant, according to the data provided by the AEs, corresponds to a Natural Time instant with \(\chi\approx 0.19\), which is exactly the instant at which the function \(F(\chi)\) starts increasing rapidly obeying the power law of Equation (2) (see Figure 10). Moreover, the PSC is maximized at the instant \(t\approx 480\) s, which corresponds to \(\chi\approx 0.46\), i.e., when the \(F(\chi)\) function has already attained its maximum level. In other words, a clear direct analogy is observed between the intensification of the electric activity and the respective acoustic one as it is described by the \(F\)-function in the Natural Time domain. The above conclusion is definitely supported by considering the electric current recorded during the protocol with mutually interconnected marble blocks under shear, discussed in Section 3.4. The respective evolution of the PSC is plotted in Figure 14.  
Figure 14: The temporal evolution of the PSC recorded during the experiment with mutually interconnected marble blocks under pure shear, that was discussed in Section 3.4. Figure 13: The temporal evolution of the PSC recorded during the diametral compression of the circular semi ring specimen discussed in Section 3.3. It is seen that the strong intensification of the electric activity is detected at the instant \(t\approx 865\) s, corresponding to \(\chi\approx 0.91\), which is again the instant at which the function \(F(\chi)\) starts increasing rapidly obeying the power law of Equation (2) (see Figure 12b). Similarly, the PSC attains its peak value at \(t\approx 874\) s which corresponds to \(\chi\approx 0.985\), the instant at which the \(F\)-function, in terms of the Natural Time domain has, also, attained its peak value. Quite similar conclusions concerning the temporal evolution of the PSC and its close agreement with the respective one of the \(F\)-function analyzed in the Natural Time domain are drawn from the electric activity recorded during the remaining protocols of this study. Clearly, further research is needed with additional experimental protocols and a wider range of materials. In any case, the conclusions of this preliminary study are encouraging, indicating, at least, that the topic deserves further attention. Conceptualization, D.T. ; methodology, D.T. and A.L. ; experimental, E.D.P., S.K.K., A.L. and I.S. ; writing--original draft preparation, D.T. ; writing--review and editing, S.K.K., A.L., E.D.P. and I.S. ; visualization, S.K.K. ; supervision, D.T. and S.K.K. ; project administration, D.T. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. The authors declare no conflict of interest.
# Acoustic Scattering Models from Rough Surfaces: A Brief Review and Recent Advances
## 3 Historical Approximations
### The Kirchhoff Approximation
#### 3.2.2 Validity
Notably, Figure 2 in [52] represents the stated validity of first-order perturbation theory and KA in \(k\sigma\)-\(kL\) space obtained for bistatic scattering cross sections simulation: PT is said valid for small \(k\sigma<2\) to 4 depending on \(kL\) value, KA valid for \(kL>6\) and both KA and first-order PT needs \(\sigma/L<C\) (\(C\) being a constant value). In our opinion, this KA condition \(kL>6\) is too restrictive for many applications, such as non-destructive evaluation, which often employs near specular observation inspection. First, we previously study or carry out numerical comparisons of KA simulation for cracks of finite size \(L\) inspected with longitudinal waves in solids with numerical methods: the method of optimal truncation (MOOT) [80] and a finite element method (FEM) [81; 82]. These comparisons with MOOT [83] and FEM [69; 84] both show that KA is valid for near specular observation inspection for \(kL>2\). [PERSON] et al. [77] did not propose a validity criterion on \(kL\) (but only the condition on \(\sigma^{2}/L\)); they nevertheless obtained an acceptable disagreement of 2 dB(see their Figure 10 [77]) for \(kL=\pi/2\) (corresponding to L = \(\lambda\)p/4) and for an important roughness \(\sigma=\lambda\)p/4 = \(L\) equal to the correlation length. It is a pity that that they did not provide numerical validations below \(kL=\pi/2\). Our conclusive opinion is that for many applications using rather near specular observation and non-grazing incident angles, two criteria can be used for KA validity: \(\sigma^{2}/L\leq C\lambda\)p and \(\mathrm{kL}>1\) or 2. For more important observation angles to the normal the criterion on \(\mathrm{kL}\) and the constant C value are likely to be a little more restrictive: [PERSON] [85] using 2D FEM calculations recently showed that KA can be considered accurate for \(\mathrm{kL}>\pi\) and for incidence and scattering angles over the range from \(-80^{\circ}\) to \(80^{\circ}\). Figure 5: [PERSON]’s Figure 11 [77]. Scattered amplitude versus observation angle using 2D finite element (FE) and Kirchhoff approximation (KA) simulations, for \(\theta\)i = \(0^{\circ}\), \(\sigma=\lambda\)p/3, \(L=0.6\)\(\lambda\)p. Reproduced with permission from [77], Royal Society, 2015. Figure 6: [PERSON]’s Figure 12 [77]. (**a**) [PERSON]’s Figure 11 [77]. Scattered amplitude versus observation angle using 2D FE and KA simulations, for \(\theta\)i = \(30^{\circ}\), \(\sigma=\lambda\)p/3, \(L=\lambda\)p/2 \(<0.6\)\(\lambda\)p. (**b**) Error between 2D FE and KA with respect to \(\theta\)i in the specular direction for different values of \(\sigma\). Reproduced with permission from [77], Royal Society, 2015.
# Analysis of Water Quality Improvement Effect of Controlled River by Multi-Functional Weir Operation
## 3 Study Methods
### Calibration & Validation of EPDC Model  
To correct the errors in the parameters of the hydrodynamic model, the water level data measured from the upstream area of the Dalseong Weir from 1 January to 1 December 2014 were compared with the numerical simulation results. The parameters of the hydrodynamic model were corrected through a trial-and-error method. After correcting the parameters, the results were compared with the observation results and an R\({}^{2}\) of 0.82 was obtained. Flow simulation was performed using the corrected parameters, and the results were compared with the water level data measured from 1 January to 1 September 2015. Here too, an R\({}^{2}\) of 0.82 was obtained and it was possible to appropriately reproduce the flow of the simulated section using the corrected parameters.  
For the water quality model for simulation, appropriate parameter values were selected through a comparison of the measurement results presented by NIER [23]. For parameter correction of the water quality model, the water quality data measured at the  
Figure 4: Survey Location of Water Quality Gangjeong-Goryeong Weir and Dalseong Weir Section.  
Figure 3: Test bed Section Geographic Construction.  
Hwawon-naru and Goryeong water quality observatories from 1 January to 1 December 2014 were used. Figure 5 is a graph that compares the results of the water quality simulation with the corrected parameters and the measurement results of the Hwawon-naru and Goryeong water quality observatories. The five water quality factors (Chl-a, DO, COD, T-N, and T-P) measured at the Hwawon-naru and Goryeong water quality observatories showed errors of less than 20% and the daily change in each of these water quality factors could be reproduced effectively.  
To verify whether the corrected parameters of the water quality model could be applied to other periods, the water quality data were measured at the Hwawon-naru and Goryeong water quality observatories from 1 January to 1 September in 2015 were compared with the simulation results. Figure 6 is a graph that compares the time series data of each water quality factor with the numerical simulation results. The numerical simulation results reflected the daily change in each water quality factor, and the average error from the observation results was within approximately 20%. This indicates that the corrected parameters for the simulation section can be applied to other periods.  
Figure 5: Water Quality Simulation Calibration (From January 2014 to December 2014).
# E-MQTT: End-to-End Synchronous and Asynchronous Communication Mechanisms in MQTT Protocol
## 2 Related Works
### Applications of MQtt  
MQTT finds application across diverse domains, encompassing platforms such as Floodnet [7; 8], Facebook Messenger [12], and wireless heart rate monitoring systems [5]. MQTT's versatility extends to sectors like healthcare [54], energy, and utilities, as well as social networking systems [13]. Grgic's research [6] innovatively employed MQTT within agricultural drying processes, while MQTT-driven home automation systems empowered remote monitoring of home environments, along with the execution of necessary tasks [3].
## 4 Conclusions
The results overall with downscaled SIF were encouraging given that only a single scaling factor was used and considering that the input datasets have since been updated. However, to be further improved, it is likely that variations in fluorescence escape from the canopy and fluorescence yield will have to be better accounted for. The reflectance-based models were able to take advantage of high fidelity imager reflectance data with low noise and consequently high spatial resolution and frequent revisit. Our results suggest that machine learning or other similar approaches may benefit from the use of these data along with SIF. While our approach of using a static low resolution SIF dataset to detect high productivity areas is not optimal and can be improved, the number of grid boxes with high SIF relative to NDVI was only approximately 2-3% of all land grid boxes, excluding Antarctica. Therefore, small errors due to temporal variability or the fact that only a fraction of those grid boxes may contain high productivity crops are unlikely to have a significant impact on our global annual GPP estimates. The results obtained here may be further improved using higher spatial resolution SIF data ideally taken over several years, such as from the recently launched TROPOpsheric Monitoring Instrument (TROPOMI) with ground footprints \(\sim\)7 km \(\times\) 3.5 km at nadir and complete daily global coverage ([PERSON] et al., 2015). Conceptualization, J.J. Formal analysis, J.J., Y.Y., Y.Z., G.D., M.J., A.L. and Y.W. Investigation, J.J., Y.Y., Y.Z., G.D., M.J. Software, J.J., Y.Y., Validation, J.J., Y.Y., Y.Z., G.D., M.J. Visualization, J.J. and Y.Y. Writing, original draft preparation, J.J. Writing, review and editing, all. This research was funded by NASA. **Acknowledgments:** We are grateful to EUMETSAT for providing the GOME-2 data and NASA for providing the MODIS, CERES and GMAOdatasets used in this study. Funding for this work was provided by the NASA Earth Science U.S. Participating Investigator program. We also thank [PERSON] for helpful discussions. We thank all investigators who provided data as part of the FLUXNET 2015 Tier 1 dataset. This work used eddy covariance data acquired and shared by the FLUXNET community, including these networks: AmeriFlux, AfriFlux, AsiaFlux, CarboAfrica, CarboEuropeIP, CarbolItaly, CarboMont, ChinaFlux, Fluxnet-Canada, GreenGrass, ICOS, KoFlux, LBA, NECC, OzFlux-TERN, TCOS-Siberia and USCCC. The ERA-Interim reanalysis data are provided by ECMWF and processed by LSCE. The FLUXNET eddy covariance data processing and harmonization were carried out by the European Fluxes Database Cluster, AmeriFlux Management Project the and Fluxdata project of FLUXNET, with the support of CDIACand ICOSEcosystem Thematic Center and the OzFlux, ChinaFlux and AsiaFlux offices. **Conflicts of Interest:** The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses or interpretation of data; in the writing of the manuscript; nor in the decision to publish the results.
# Improved Cryptanalysis of Some RSA Variants
## 2 Preliminaries
### Useful Lemmas  
Given a positive integer of the form \(N=pq\) with \(q<p<2q\), the following result provides the limiting values for \(p\) and \(q\) in relation to \(N\), as well as the prime sum \(p+q\) (see ([PERSON] et al., 2018)).  
**Lemma 1**.: _Let \(p\) and \(q\) be prime numbers satisfying \(N=pq\) and \(q<p<2q\). Then, one finds that_  
\[\frac{\sqrt{2}}{2}N^{\frac{1}{2}}<q<N^{\frac{1}{2}}<p<\sqrt{2}N^{\frac{1}{2}}, \quad p+q<3N^{\frac{1}{2}}.\]  
The subsequent result shows that, given an approximation of \(p\) for a modulus \(N=pq\), one can also approximate both \(q\) and \(p+q\) (see ([PERSON] et al., 2018)).  
**Lemma 2**.: _Let \(N=pq\) be the product of two prime numbers \(p\) and \(q\) with \(q<p<2q\). Assume that \(\bar{p}\) is a known approximation of \(p\) with \(|p-\bar{p}|\leq N^{\sigma}\). Then, \(\bar{q}=\left\lfloor\frac{N}{\bar{p}}\right\rfloor\) approximates \(q\), and_  
\[|q-\bar{q}|<N^{\sigma},\quad|p+q-(\bar{p}+\bar{q})|<2N^{\sigma}.\]
# Covert Communication for Integrated Satellite-Terrestrial Relay Networks with Cooperative Jamming
## 2 System Model and Problem Formulation  
Primarily, we propose a specific covert system model. Then, the related signal model is explored. Last, based on the above, the problem we research is formulated.