esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Optical Measurement Process
### Signal Integrity Characterization  
The signal integrity characterization set-up shown in Figure 15 is described as follows. A 10.3125 Gb/s PRBS 231-1 test pattern was generated by an Anritsu MT1810 pulse pattern generator (PPG) and used to drive either a commercial 850 nm or 1310 nm XFP transceiver. As with the insertion loss measurements, a mode conditioner was used to ensure the near field modal distribution at the fiber launch complied with the EF requirements set out in IEC 61280-4-13. The output from the waveguide was conveyed by an OM2 fiber through a variable optical attenuator into a Tektronix CSA8000B communications signal analyzer (CSA). By selection of either the 850 nm or 1310 nm XFP transceiver, signal integrity measurements were carried out at 850 nm for polymer and 1310 nm for glass waveguides. Back-to-back signal integrity reference measurements were carried out for each wavelength, whereby a variable optical attenuator (VOA) was used to adjust the signal power amplitude received at the CSA to be equal to the measured power for each given waveguide measurement in order to compensate for any jitter dependence of the CSA on received power levels.  
Figure 15: Signal integrity measurement set-up.  
Figure 16 shows eye diagrams of the waveguides under test at their respective best operating wavelength (1310 nm for glass waveguides, 850 nm for both types of polymer waveguides) with minimal added signal distortion apparent.  
Bit Error Rate testing was also carried out on the waveguides at their respective best operational wavelengths using an Anritsu MT1810 signal analyzer (Anritsu Corporation, Tokyo, Japan). A bit error rate of less than \(10^{-12}\) was measured on all waveguides.
## 3 Results
### Experimental Results
#### 4.1.2 Comparative Examination with Other Research Models  
Our proposed methodology is validated by comparing its results with previous research endeavors focusing on identifying the earliest signs of Alzheimer's disease using a  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Class Name** & **Precision** & **Recall** & **F1 Score** \\ \hline Mild & 0.97 & 0.99 & 0.98 \\ Normal & 1.00 & 0.87 & 0.93 \\ Moderate & 0.99 & 0.98 & 0.98 \\ Very Mild & 0.97 & 0.99 & 0.98 \\ Accuracy & 98.13\% & & for predictions \\ \hline \hline \end{tabular}
\end{table}
Table 4: Report of classification.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Class Name** & **Accuracy** & **Class Name** & **Precision** & **Recall** & **F1 Score** \\ \hline SVM & 96.56 & Mild & 0.95 & 0.98 & 0.96 \\  & & Normal & 1.00 & 0.81 & 0.90 \\  & & Moderate & 0.97 & 0.98 & 0.97 \\  & & Very Mild & 0.97 & 0.94 & 0.96 \\ LGBM & 96.17 & Mild & 0.98 & 0.98 & 0.98 \\  & & Normal & 1.00 & 0.31 & 0.48 \\  & & Moderate & 0.96 & 0.98 & 0.97 \\  & & Very Mild & 0.95 & 0.95 & 0.95 \\ Ensemble SVM-LGBM & 95 & Mild & 0.98 & 0.95 & 0.97 \\  & & Normal & 0.33 & 0.50 & 0.40 \\  & & Moderate & 0.95 & 0.95 & 0.97 \\  & & Very Mild & 0.98 & 0.92 & 0.95 \\
**Proposed Model** & **98.13** & **Mild** & **0.97** & **0.99** & **0.98** \\  & & **Normal** & **1.00** & **0.87** & **0.93** \\  & & **Moderate** & **0.99** & **0.98** & **0.98** \\  & & **Very Mild** & **0.97** & **0.99** & **0.98** \\ \hline \hline \end{tabular}
\end{table}
Table 5: Report of classification comparisons.  
four-class categorization system, presented in Table 6. The suggested ImFCM-Ws-CNN-LSTM model exhibits an enhanced accuracy, precision, and F1 score, proficiently discerning the four different types of Alzheimer's disease with 96.25% accuracy, 98.0% precision, and a 97% F1 score.
## 4 Discussion
### The Mechanism of Petrophysical Differences
#### 4.2.2 The Influence of Laminas Structure on Permeability  
Previous research results show that the permeability perpendicular to the bedding of laminas shale is higher than that of homogeneous shale, and the difference in permeability can reach two to eight times [57; 58]. The influence of laminas structure on permeability can be better explained by comparing the mineral structure of marine and continental shale. As Table 4 presented, the permeability of 0\({}^{\circ}\) marine shale samples is 1.39 times that of the 90\({}^{\circ}\) samples, whereas the permeability of 0\({}^{\circ}\) continental shale samples is 3.41 times that of the 90\({}^{\circ}\) samples. The possible reasons are: (1) As mentioned above, the continental shale consists of high density and frequency of developed laminas, showing more heterogeneity compared to marine shale. In addition, the lithological stratification in millimeter-scale is prone to become the dominant migration pathway, leading to increasing the cross-bedding permeability; (2) The clay mineral structure also has an influence on the permeability. The clay minerals in the continental shale show strong orientation along with the bedding, while the clay minerals of marine shale are mostly distributed randomly or around rigid minerals without significant orientation (Figure 10). The complex structure of the clay matrix in marine shale results in a reduction in permeability.  
Figure 10: The relative length and angle of clay minerals distributed in marine and continental shale (the relative length is calculated based on Equation (1)). The angle represents the clay mineral orientation based on the same calibrated bedding plane. Moreover, the degree of sparsity represents the dominated orientation (60–110\({}^{\circ}\) and 238–285\({}^{\circ}\) are the dominated orientation for continental shale, whereas there is no dominated orientation of clay mineral in marine shale).
## 3 Results and Discussion
### Angular Characteristics
#### 3.3.1 Laser with a Flat Cavity
The angular energy distribution shows that the energy irradiated at angles larger than 20 mrad may exceed 30% of E\({}_{589}\). The beam profile core fits a super-Gaussian distribution and remains almost unchanged at large I\({}_{532}\) values, whereas the E\({}_{589}\) part, irradiated at large angles, increases. This is why we suppose that the energy of the wings cannot be attributed to the tails of the generated resonator modes. We suppose that this radiation may appear via scattering inside the laser cavity of the main 589 nm radiation and the subsequent amplification and irradiation of the scattered light within a plane angle \(\Theta\) determined by the dimensions of the pump channel in the KGW crystal:  
\[\Theta=n\times a/1\]  
where n is the refraction index and l is the crystal length. For the a\({}_{1}\) = 4 mm spot, we obtained \(\Theta\) = 160 mrad. Thus, this radiation is irradiated into a solid angle, which is 40 times larger than the solid angle of the white spot. Supposing that this energy is 30% of the total E\({}_{589}\) and has a uniform angular distribution, the average intensity of this radiation is calculated to be 80 times less than the average intensity within the white spot. It is not surprising that this radiation was not recorded at the imprints. Undepleted single-pass gain increment in 50 mm KGW crystals at 589 nm under double-pass pumping at I\({}_{532}\) = 350 MW/cm\({}^{2}\) can be larger than 35, and it does not depend on the direction of light propagation. Tilted beams can undergo an even larger amplification than beams propagating in parallel to the cavity axis direction. A larger Raman gain coefficient and larger lateral dimensions of the pump channel in the crystal are advantageous for the amplification of tilted beams and wing growth. Our supposition corresponds to the experimental results shown in Figure 5.0 we see that the angular energy divergence of the Raman laser increases with pump intensity, which is proportional to the Raman gain coefficient, and with an increase in the pump spot size (compare curves a-b for a 2 mm spot and c-d for a 4 mm spot). Also, when a KGW crystal with Brewster ends was used, the angular spread of laser radiation increased \(\sim\)2-fold parallel to the polarization plane, in accordance with pump beam widening in the crystal, but the angular spread in the orthogonal direction remained unchanged.
# Upgrades of a Small Electrostatic Dust Accelerator at the University of Stuttgart
## 2 Materials and Methods
### Focusing System Upgrade  
In order to collimate dust particles, a focusing system located behind the dust source is needed. Charged dust particles can be focused using electric fields (electrostatic force) or magnetic fields (Lorentz force). We compared two electrostatic lens systems (a single-cylinder system and an earlical lens system, see Figure 5) in the small accelerator with an acceleration voltage of 15 kV. The shape of the single-cylinder focusing system is similar to the one used in our 2 MV dust accelerator facility [6]. The particularly shaped metal cylinder with an inner diameter of 8 mm is directly behind the dust source. The earl lens consists of three separated cylindrical electrodes. The central electrode is connected to high voltages to generate lens effects and the other two electrodes are grounded.  
\begin{table}
\begin{tabular}{c l l} \hline \hline
**Parameter** & **Description** & **Value** \\ \hline \multirow{3}{*}{Size} & Length \(\times\) Diameter & 127 mm \(\times\) 127 mm \\  & Reservoir & \(\phi\) = 12 mm, length = 25 mm \\  & Distance (Needle-extraction hole) & 2.5-4 mm \\ \hline \multirow{3}{*}{Material} & Chassis & Stainless steel \\  & Insulators & PEEK \\  & Needle & Tungsten \\  & HV feedthrough (40 kV) & Alumina ceramic \\ \hline \multirow{2}{*}{Voltage} & Needle & 0-30 kV, fixed \\  & Reservoir & same as needle, pulsed \\ \hline \multirow{2}{*}{Pulses} & Duration & 1-255 ms, adjustable \\  & Repetition & 1–255 ms, adjustable \\ \hline \hline \end{tabular}
\end{table}
Table 2: Parameters of the upgraded dust source.  
Figure 4: Schematic diagram and realistic picture of the new dust source. Dust particles are charged by contact with the reservoir surface. Charged particles will be levitated by the electrostatic force. Particles close to the exiting hole and the needle will be fired out. The potential drops to ground (0 V) on the extraction plate.  
Figure 5: Schematic diagram of focal electrodes (**left**: single cylinder system; **right**: einzel lens system) and simulations of the focusing effect in SIMION. The potentials of the electrodes were altered to show the focusing effect.  
The relation between the focal length and electrode potential is shown in Table 3. The focal length is calculated between the dust source and the focal point. The focal length is affected by the electrode geometry and focusing and acceleration voltages. Based on our simulation results and operation experiences, for a given acceleration voltage, the focal point of the dust beam is altered by varying the potential of the focusing electrode according to the experimental requirements.
# CT-RPL: Cluster Tree Based Routing Protocol to Maximize the Lifetime of Internet of Things
## 3 Cluster Tree-Based Routing Protocol
### Route Establishment
#### CH Rank Calculation  
The \(CH\) rank exhibits the number of hops between the DODAG root and participant \(CH\). The rank of \(CH\), \(CH_{r}\) of node \(X\), is computed from the rank increase value, \(r_{i}\) and the \(CH\) parent rank \(r_{p}\) of \(X\). \(r_{i}\) is the summation of step value \(s_{v}\) and minimum hop rank increase \(r_{min}\). The value of \(r_{i}\) is fixed, which is 256 [59]. \(s_{v}\) is calculated from the objective function \(OF_{(QU,ETX)}\).  
\[CH_{r}\ (X)=r_{p}\ (X)+r_{i} \tag{20}\]  
\[r_{i}=s_{v}+r_{min} \tag{21}\]  
In CT-RPL, the cluster formation computational complexity is O(CDK), where C, D, and K indicate the number of clusters, dimensions of each point to be clustered, and the number of nodes to cluster. The computational complexity of the \(CH\) selection and multi-hop route establishment are O(n^3) and O(n). The overall computational complexity is O(n^3). The overall working mechanism of CT-RPL is given in Algorithm 1.  
After the deployment of nodes and the formation of clusters, the maximum reward values are compared, and the minimum \(CH\) parent rank is chosen after route establishment, based on which data transfer occurs, until the residual energy diminishes.
# Novel Multi-Level Dynamic Traffic Load-Balancing Protocol for Data Center
## 3 Motivation of the Study
### Summary  
Our analysis leads us to conclude that the congestion mismatch problem occurs due to the continuous path rerouting, which is happening because of the sending rate and the rerouting state of the new path and the dynamic rerouting within a flow that allows the various congestion states of the paths to adjust the rate of newer paths. These outcomes inspire us to handle the congestion mismatch problem by reducing rerouting to the minimum. We overcome the mismatching problem that is proved by improving the flow completion time (FCT) and the throughput, and we implemented our scheme to not reroute until it is a critical situation such as failure or very bad paths, so that the rerouting is minimized as much as possible.
## 6 Numerical Results
### Energy Efficiency  
Figure 9 compares EE with a different number of relay nodes, where \(Q=12\) dB and \(P_{T}=12\) W. From it, we can find that the EE increases as the number of relay nodes increases. At the same time, corresponding to Figure 3, when the number of relay nodes increases to five, the influence of the relay node's number gradually weakens. In addition, we can also find that our designed EEAB-SWIPT obtains the highest EE. This is for the same total transmit power; our designed EEAB-SWIPT has the highest transmission rate.  
Figure 10 compares EE with different total transmit powers, where \(Q=12\) dB and the number of relay nodes is six. From it, the following information can be obtained: (1) The EE first increases and then decreases with the increases in total transmit power. At the same time, the maximum EE is obtained at around 6 W. When the transmit power increases to a certain level, corresponding to Figure 4, the increases in transmit power cannot bring sufficient increases in transmission rate. That is, from (28), the growth in the denominator is higher than that of the numerator, and thus the network EE keeps decreasing. (2) Corresponding to Figure 4, with the increases in total transmit power, the EE under EEAB-SWIPT is the highest, and the NC is the lowest. This is because when compared with the other transmission strategies, our EEAB-SWIPT achieves the adaptive transmission, optimizes each node's power allocation, and uses the SWIPT-PS protocol to transmit the energy-constrained node's signal, simultaneously. With Figures 9 and 10, we can find that the designed EEAB-SWIPT can effectively improve the network EE.  
Figure 11 compares EE of the EEAB-SWIPT and AB-SWIPT with a different PS coefficient \(\rho\). From it, we can find that no matter whether the total transmit power is 15 W or 20 W, the EE first increases and then decreases. At the same time, the maximum EE is also achieved at around \(\rho=0.8\), which corresponds to Figure 5. In addition, unlike in the Figure 5, the EE at 15 W is higher than that at 20 W under the same transmission strategy. This is because, as shown in Figure 10, after the EE reaches its maximum at 6 W, it then decreases with the total transmit power increases. Therefore, the EE at 20 W is lower than that at 15 W. However, when compared with the AB-SWIPT, the EEAB-SWIPT obtains a higher EE with the OPA, which can verify the effectiveness of our EEAB-SWIPT transmission strategy.  
Figure 9: The EE vs. the number of relay nodes.
# A 1 \(\times\) 2 Two-Dimensional Slanted Grating Based on Double-Layer Cylindrical Structure
## 4 Conclusions  
Diffraction gratings play an increasingly important role in various planar optical systems. At present, no one has proposed a 2D slanted grating suitable for 3D display. In this work, we propose a two-dimensional slanted grating based on a double-layer cylindrical structure by using rigorous coupled-wave analysis. The two-dimensional slanted grating was proposed based on a two-layer cylindrical structure, which can achieve high diffraction efficiencies for the (0, \(-\)1) and (\(-\)1, 0) orders under normal incidence for TE and TM polarization. The maximum total efficiency of the grating is up to 78%. The diffraction efficiencies of the (\(-\)1, 0) order and the (0, \(-\)1) order are both greater than 30% when the incident angle ranges from \(-\)3.2\({}^{\circ}\) to 3.2\({}^{\circ}\). Tolerance analysis was performed for each structural parameter of the grating. Suitable manufacturing tolerances were calculated for the height of the two-layer cylindrical structure, grating inclination, and duty cycle, and the grating period deviated from the optimal results. The total effective efficiency is greater than 75% when the MgF\({}_{2}\) thickness is from 300 nm to 350 nm, and the SiO\({}_{2}\) thickness is from 525 nm to 550 nm. Furthermore, the grating period has a 53 nm fabrication tolerance, and the slanted angle has a 8.8-degree fabrication tolerance. The relatively large tolerances ensure that it is easy to fabricate the two-dimensional slanted grating and to achieve the targeted objectives. The proposed two-dimensional slanted grating can be applied to 2D exit pupil expansion, and the easy availability of materials greatly reduces the cost of production manufacturing, which has the potential to meet AR/VR and 3D display requirements.  
[PERSON], [PERSON] and [PERSON] conceived the idea of this article. [PERSON] and [PERSON] completed the work of acquisition of data. [PERSON] and [PERSON] shared the task of analysis and interpretation of data. [PERSON] and [PERSON] provided funds for the project. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Guangdong Provincial Pearl River Talents Program (2019 ZT08 ZZ79); the Guangzhou Science and Technology Program Key Projects (202007010001); the National Natural Science Foundation of China (U21A20509); and the National Natural Science Foundation of China (62205124).  
Not applicable.  
Figure 8: Grating diffraction efficiency versus duty cycle\(f\); (**a**) TE polarization; (**b**) TM polarization.
## 3 Slipstream Velocities
### Effect of Yaw Angle
In the boundary layer region, at \(y=2.25\) m and \(y=2.81\) m, the no-crosswind case has the fastest decaying velocity, and the \(21.8^{\circ}\) cases remain at a high velocity, resulting from the crosswind effect. The larger lateral velocity component causes additional air to pass through the train body, which then accelerates around the leeward tail of the train. This observation is qualitatively analogous to that suggesting the flow is quite three-dimensional along the train when it is running in a crosswind. For comparison of the two crosswind cases with \(21.8^{\circ}\) yaw angles, different train speeds and wind speeds are different to the slipstream generation, and the slipstream velocities from the two cases are put in the vast difference. Despite the difference decreasing depending on the distance from the train side increase, the fluctuating range of the external flow curve is higher, and even the flow curve crossover occurs under different train speeds and wind speeds. It seems to reveal the effect of the bridge on the slipstream under the crosswind. In addition, the slipstream velocities distribution of the moving train varies with different measuring points, predominantly between the different distances from the bridge deck. First, the slipstream velocities from \(z=1.55\) m measure points at the higher position, indicating that the results of train-induced slipstream stack with crosswind are pure. Due to a shielding effect on the bridge deck on the leading edge, the slipstream velocities from \(z=1.21\) m have more variability. The higher position from the bridge deck, the fewer interferences from the bridge deck appear to be. Figure 8: Ensemble\(-\)averaged \(U\) on the windward side of the train at \(z=1.21\) m for (**a**) \(y=1.68\) m, (**b**) \(y=2.25\) m, (**c**) \(y=2.81\) m.
# A Network-Based Method to Analyze EMI Events of On-Board Signaling System in Railway
## 1 Introduction
On the other hand, concerning the EM interference (EMI) problems and equipment susceptibility of OTCS, most of the subsystems had been studied in different ways such as the GSM-R (Global System for Mobile Communications-Railway) [14; 15], balise transmission module [5; 16], track circuits [17; 18], and cables [19]. Various solutions have been attempted to improve the OTCS EMC according to the interactions between the sources and equipment as mentioned above. Nevertheless, there is no detailed and distinct methodology framework on how to assess the whole system due to the complex couplings, huge scale computation, and massive test data. It is not easy to get a system-level view of the OTCS EMC, because any change in every part may lead to a new procedure of the simulation or measurement. This implies that a more powerful and clear method is needed to optimize work and judgment for OTCS EMC in railway engineering. To date, there are primarily two means to study EMC problems in a complicated system. One is the lumped parameters equivalent circuits [20] and the other is transfer functions such as EM topology (EMT) [21]. Each of them has its advantages and disadvantages. Unlike the limitation in low-frequency range in the former one, the EMT method could decompose the complex system into multi-zones based on the shielding layer, and transfer functions could be adopted to describe the propagations by conduction and radiation. However, the accuracy transfer functions are not easy to obtain and the interactions between internal and external areas cannot be ignored sometimes. Therefore, we need to build a methodology for assessing the EMC of the whole OTCS, which may make engineers have the best understanding to have a global view. In this work, we introduced a method based on network theory [22] to combine the tube and junction idea in EMT according to relevant electrical and EMC properties of the subsystems. A topological network is proposed with the edges and nodes to describe the interaction between the EM environment and the OTCS. The coupling and real connection between the sources and componentsare described in OTCS. The description and definition of the parameters for elements in the constructed model of OTCS are explained. In Section 2, a novel EMC network framework and method are presented. Section 3 explains the network model of the OTCS in detail. In Section 4, the real case study for the subsystem from OTCS is implemented to verify the effectiveness of the proposed approach. Section 5 presents the conclusion.