esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Circuit Level Design
### Power Stage MOSFETs  
In the development of a DC-DC synchronous buck converter, critical attention must be devoted to the design of power transistors, specifically the NMOS and PMOS devices utilized within the converter architecture. To design these transistors, the fundamental long-channel equations (1)-(3) for the triode region were utilized [36], where \(I_{D}\) is the drain current, \(R_{on}\) is the on resistance, \(C_{GS}\) is the gate-source capacitance, \(\mu\) is the carrier mobility, \(C_{ox}\) is the oxide capacitance, \(W\) is the transistor width, L is the transistor length, \(V_{GS}\) is the gate-source voltage, \(V_{TH}\) is the threshold voltage, \(V_{DS}\) is the drain-source voltage, and \(C_{ov}\) is the overlap capacitance.  
\[I_{D}\approx\mu C_{ox}\frac{W}{L}(V_{GS}-V_{TH})V_{DS} \tag{1}\]  
\[R_{on}\approx\frac{1}{\mu C_{ox}\frac{W}{L}(V_{GS}-V_{TH})} \tag{2}\]  
\[C_{GS}\approx\frac{WLC_{ox}}{2}+WC_{ov} \tag{3}\]  
In power electronics, in the design of a transistor cell with SiC MOSFET, the primary goal is to typically find the optimal trade-off between \(R_{on}\) and the breakdown voltage \(V_{BR}\)[37]. A similar aspect is considered in GaN-based devices, where \(R_{on}\) and the breakdown voltage \(V_{BR}\) depend on the gate parasitic inductor \(L_{g}\)[38]. On the other hand, in the IISB's 2 \(\mu\)m 4H-SiC CMOS technology, the breakdown voltage \(V_{BR}\) is commonly considered fixed at 40 V [39; 40]. According to (2), minimizing \(R_{on}\) can be achieved by maximizing the aspect ratio (\(W/L\)) and using the maximum gate-source voltage \(V_{GS}\). The other factors in the equation, such as \(\mu\) and \(C_{ox}\), are intrinsic properties of the material and process, fixed for this technology. Another crucial design consideration is the validity of these equations within the specific operating region [41]. The equations are accurate under the condition where \(V_{DS}\ll 2(V_{GS}-V_{TH})\). This implies that the drain current (\(I_{D}\)) must be within a range that satisfies this condition, as derived from (1). Ensuring operation within this range is essential for maintaining the accuracy of the model and achieving optimal transistor performance.  
Furthermore, the gate capacitances (\(C_{GS}\)) of the PMOS and NMOS transistors are simulated, recognizing that each transistor type exhibits distinct capacitance values. These values are essential as they significantly influence the switching characteristics and the efficiency of the converter. The differences in capacitance impact the driver circuit design, where there is a need to facilitate rapid and efficient switching, thereby minimizing power losses [42]. Additionally, these capacitances are roughly proportional to the area of the transistors, as shown in (3).
## 5 Experimental Evaluation
### Data Preparation and Evaluation Metrics
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline
**Feature Pattern** & **No. of Features** & **Accuracy** & **Precision** & **Recall** & **F1-Measure** \\ \hline \multirow{4}{*}{**U**} & 24,961 (100\%) & 79.08 & 79.68 & 79.08 & 79.21 \\  & 19,969 (80\%) & 75.37 & 78.26 & 75.37 & 75.73 \\  & 16,225 (65\%) & 38.9 & 84.77 & 38.9 & 36.53 \\  & 12,481 (50\%) & 20.43 & 68.05 & 20.43 & 14.89 \\ \hline \multirow{4}{*}{**B**} & 165,704 (100\%) & 17.64 & 56.32 & 17.64 & 11.67 \\  & 132,563 (80\%) & 17.6 & 54.71 & 17.6 & 11.33 \\  & 107,708 (65\%) & 16.93 & 45.3 & 16.93 & 13.31 \\  & 82,852 (50\%) & 19.83 & 51.72 & 19.83 & 14.65 \\ \hline \multirow{4}{*}{**T**} & 181,514 (100\%) & 16.28 & 29.99 & 16.28 & 9.51 \\  & 145,211 (80\%) & 12.08 & 39.05 & 12.08 & 7.13 \\  & 117,984 (65\%) & 17.61 & 57.99 & 17.61 & 10.29 \\  & 90,757 (50\%) & 16.99 & 47.62 & 16.99 & 11.98 \\ \hline \multirow{4}{*}{**Q**} & 168,482 (100\%) & 15.34 & 34.68 & 15.34 & 5.81 \\  & 134,786 (80\%) & 14.71 & 49.57 & 14.71 & 6.33 \\  & 109,513 (65\%) & 15.82 & 32.81 & 15.82 & 7.86 \\  & 84,241 (50\%) & 15.66 & 56.46 & 15.66 & 6.29 \\ \hline \multirow{4}{*}{**U,B**} & 190,665 (100\%) & 78.95 & 79.25 & 78.95 & 79.03 \\  & 152,532 (80\%) & 78.51 & 79.32 & 78.51 & 78.71 \\  & 123,932 (65\%) & 76.34 & 78.76 & 76.34 & 76.81 \\  & 95,333 (50\%) & 75.72 & 78.49 & 75.72 & 76.16 \\ \hline \multirow{4}{*}{**B,T**} & 347,218 (100\%) & 16.16 & 26.71 & 16.16 & 10.41 \\  & 277,774 (80\%) & 16.87 & 56.63 & 16.87 & 11.31 \\ \cline{1-1}  & 225,692 (65\%) & 16.08 & 43.69 & 16.08 & 11.79 \\ \cline{1-1}  & 173,609 (50\%) & 16 & 44.39 & 16 & 13.2 \\ \hline \multirow{4}{*}{**T,Q**} & 349,996 (100\%) & 15.7 & 27.41 & 15.7 & 8.64 \\ \cline{1-1}  & 279,997 (80\%) & 16.43 & 41.75 & 16.43 & 8.44 \\ \cline{1-1}  & 227,497 (65\%) & 15.28 & 48.77 & 15.28 & 8.99 \\ \cline{1-1}  & 174,998 (50\%) & 16.69 & 43.51 & 16.69 & 11.05 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Experimental results for kNN classifier.
###### Abstract  
Due to the global coverage and real-time access advantages of the Tracking and Data Relay Satellite System (TDRSS), the demonstration platform based on TDRSS can satisfy the new technology verification and demonstration needs of the space information network (evolution from sensorweb). However, the comprehensive evaluation research of this demonstration platform faces many problems: complicated and diverse technical indicators in various areas, coupling redundancy between indicators, difficulty in establishing the number of indicator system layers, and evaluation errors causing by subjective scoring. Concerning the difficulties, this paper gives a method to construct this special index system, and improves the consistency of evaluation results with Analytic Hierarchy Process in Group Decision-Making (AHP-GDM). A comprehensive evaluation index system including five criterions, 11 elements, more than 30 indicators is constructed according to the three-step strategy of initial set classification, hierarchical optimization, and de-redundancy. For the inconsistent scoring of AHP-GDM, a high-speed convergence consistency improvement strategy is proposed in this paper. Moreover, a method for generating a comprehensive judgment matrix (the aggregation of each judgment matrix) aggregation coefficient is provided. Numerical experiments show that this strategy effectively improves the consistency of the comprehensive judgment matrix. Finally, taking the evaluation of TDRSS development as an example, the versatility and feasibility of the new evaluation strategy are demonstrated.  
Keywords:space information network; tracking and data relay satellite; comprehensive evaluation index system; analytic hierarchy process +
Footnote †: journal: Sensors
# Drowsiness Detection in Drivers Using Facial Feature Analysis
## 3 Methods
### Pre-Processing
#### 3.2.5 Assess Driver State  
If the calculated MAR or ECR values meet or exceed their predefined thresholds, the system triggers warnings to notify the user about potential drowsiness. These warnings are conveyed through visual cues or audio messages, depending on the implementation design. Visual cues may include flashing lights or on-screen notifications, while audio warnings could consist of alarms or spoken messages. By incorporating these alert mechanisms, the system enhances safety by promptly notifying individuals of their drowsy state, thereby facilitating timely interventions or breaks to mitigate risks associated with impaired alertness during driving. This proactive approach not only aims to prevent accidents but also promotes awareness and responsible behavior in situations where vigilance is critical.  
* Algorithm for static threshold  
As depicted in Figure 6, when a new frame is captured, a bounding box is applied using the Dlib frontal face detector. If a face is found within the frame, it is identified and localized using the Dlib face detector, as shown in Figure 7.  
If no face is identified, the system continues to search in the subsequent frames. Once a face is detected, the Dlib shape predictor assigns the 68 facial landmark points to accurately mark it, with each point being designated its respective (x, y) markings, as illustrated in Figure 8.  
Figure 6: Proposed process for static threshold.  
Figure 7: Facial regions enclosed within bounding boxes.  
The markings for the landmark points around the eyes and mouths are used to compute the ECR and MAR values for each captured frame. Then, the computed parameters are compared to their respective thresholds (0.4 mark for MAR and 0.15 mark for ECR). The current system does not use personalized training but is instead based on generalizable thresholds proposed in the existing literature. However, incorporating prior personalized training in future versions of the model would improve accuracy and robustness across diverse individuals. If either or both criteria indicate drowsiness, a warning is triggered for the driver.
## 4 Discussion  
The 3D geological model can serve as a 3D spatial database that integrates and manages the raw data and the thematic analysis data from various geological domains. Through the techniques such as model data conversion and model slicing, it provides geological information support for different regions and thematic studies. In this study, we first  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Modeling Objects** &
\begin{tabular}{c} **Location** \\ **(Wuhan’s MDA)** \\ \end{tabular} & **Model Accuracy (\%)** \\ \hline \multirow{4}{*}{Quaternary sedimentary strata} & Central district & 93.7 \\  & Peri-urban & 78.3 \\  & Northern hilly region & 74.8 \\  & Citywide & 89.2 \\ \hline \multirow{4}{*}{Bedrock} & Central district & 89.4 \\  & Peri-urban & 75.6 \\ \cline{1-1}  & Northern hilly region & 67.3 \\ \cline{1-1}  & Citywide & 85.3 \\ \hline \hline \end{tabular}  
* Comprehensive model accuracy
* Note: The central district of the Wuhan’ MDA is located at the confluence of the Yangtze and Han River, and administratively includes Jianghan, Jiangan, Qiaokou, Hanyang, Wuchang, Qingshan, Hongshan, and East-west lake districts, while the peri-urban areas mainly include Caidian, Jiangxia, Huangpi, and Xinzhou districts.  
\end{table}
Table 3: Accuracy statistics of the 3D geological model of Wuhan’s MDA.  
postulated a common geological genesis, assuming a close correlation between the hydrogeological structural characteristics and stratigraphic structure. Based on this assumption and with the support of the 3D geological model of Wuhan's MDA, we constructed a 3D hydrogeological structural model through correlation-based inference modeling. Furthermore, by correlating it with the karst collapse mechanism in the study area, we developed a 3D karst structural model for the Baishazhou region, offering professional support for the most typical karst collapse issue in Wuhan City.
## 2 Materials and Methods
### Datasets  
This study utilized various datasets, including NDVI, GPP, temperature, precipitation, and LULC. The NDVI values were obtained from the GIMMS-NDVI 3g,v1 dataset with a temporal resolution of 15 days and a spatial resolution of 8 km from 1982 to 2015. This dataset is derived from the data collected by the Advanced Very High-Resolution  
Figure 1: Geographical location and LULC types of the study region in 1985.  
Radiometer (AVHRR) satellite of the National Oceanic and Atmospheric Administration (NOAA) and has been widely used in various research fields, including agriculture, forestry, and ecology [37]. The GPP values were obtained from a GPP dataset with a spatial resolution of 0.05\({}^{\circ}\) and a temporal resolution of 8 days for 1982-2017, which was generated by [PERSON] et al. [38] using the revised EC-LUE model. The annual mean temperature and precipitation data with a 1 km resolution for 1982-2015 were obtained from the National Tibetan Plateau Data Center. This dataset was generated using the Delta method to downscale the CRU climate dataset and the high-resolution global climate dataset published by WorldClim [39]. The observed temperature and precipitation data from the CN05 dataset [40] with a resolution of 0.5\({}^{\circ}\)\(\times\) 0.5\({}^{\circ}\) from 1982 to 2015 was utilized to calculate climate indices. The LULC dataset for China from 1985 to 2021 developed by [PERSON] et al. [41] has a 30 m horizontal resolution and will be used to analyze the transformation of nine land types (e.g., cropland, forest, shrub, grassland, water, snow and ice, barren, impervious, and wetland) in coastal China. All of the data mentioned above from 1982 to 2015 were preprocessed by projection transformation, clipping, resampling, and other methods, then converted to a raster data type with a uniform resolution of 1 km.
# Minimization of Average Peak Age of Information for Timely Status Updates in Two-Hop IoT Networks
## 2 Related Work
### Packet Concatenation for AoI Reduction  
Concatenating multiple short packets into a longer packet can enhance the reliability of short-packet communications [11; 12]. Unlike the aforementioned studies [13; 14; 15; 16; 17; 18], this paper focuses on leveraging such concatenation, along with blocklength optimization, to support timely status updates in IoT networks under short-packet communication conditions.  
The most relevant work in this context is [5], which considers a two-hop status update system, as illustrated in Figure 1, and proposes joint packet coding at the sink node. The study analyzes information freshness and reliability in terms of AoI and PER, respectively, and derives the optimal group size under fixed PER constraints. Other relevant works include [6; 7; 8], which consider two-hop status update systems similar to the one in Figure 1, specifically focusing on uplink scenarios in [6; 7] and a downlink scenario in [8]. The work in [6] applies a product code (i.e., a type of parallel concatenated code) to implement joint packet coding at the sink node. It demonstrates that product coding reduces the average AoI compared to conventional block-coded schemes and also investigates the optimal group size under fixed PER constraints, as in [5]. The study [7] compares the performance of two encoding schemes in terms of the average AoI: a joint encoding scheme and a distributed encoding scheme. These schemes correspond to the system in Figure 1 with group sizes fixed at \(N\) and 1, respectively. It derives the optimal blocklength for each scheme under a fixed group size constraint (i.e., \(N\) or 1). Furthermore, the work in [8] investigates the tradeoff between average AoI and EH in a downlink scenario and demonstrates that an optimal group size exists that simultaneously achieves high EH and low average AoI under a fixed PER constraint.  
While these works [5; 6; 7; 8] provide valuable insights into the effectiveness of concatenation for AoI reduction in short-packet communications, they either fix the blocklength (i.e., impose a fixed PER constraint) or treat the group size independently. Consequently, the joint optimization of blocklengths and group size for AoI reduction in two-hop status update systems remains only partially explored.
## 4 Experimental Setup and Results
### Experiment Results
#### 4.3.1 Emotion Induction Effectiveness  
In the 40 valid datasets, the positive emotion group had 13 participants, the negative emotion group had 13 participants, and the control group had 14 participants. The PANAS scores are summarized in Tables 3-5.  
The control group showed stable emotions, while the positive and negative emotion groups exhibited significant changes, confirming the effectiveness of the emotion induction methods.
## 5 Region-Based Features
### Other shape features  
Some other shape features computed include:  
* Region width (maximum diameter)
* Ratio of height to width of region
* Elongation, defined as the ratio of eigenvalues \(\frac{|\lambda_{2}|}{|\lambda_{1}|}\) derived from the covariance matrix of points in the region.  
* Number of voxels with \"dot\" value (described in detail below) greater than a threshold \(T_{d}\).  
The dot feature we use is based on the dot enhancement approach of [41], originally designed to enhance the objects in an image of a specific shape. For each voxel, the dot value is defined as  
\[d(\lambda_{1},\lambda_{2},\lambda_{3})=\left\{\begin{array}{ll}\frac{\lambda_ {3}^{2}}{|\lambda_{1}|},&\text{if }\lambda_{1}<0,\lambda_{2}<0,\lambda_{3}<0\\ 0,&\text{otherwise}\end{array}\right. \tag{8}\]  
where \(\lambda_{1}\), \(\lambda_{2}\), \(\lambda_{3}\) (\(|\lambda_{1}|>|\lambda_{2}|>|\lambda_{3}|\)) are three eigenvalues of the Hessian matrix calculated from second derivatives of image.  
To reduce the effect of the noise and also to take into account different object sizes, multi-scale Gaussian image smoothing is performed prior to the calculation of the second derivatives. Following [41], for objects with diameters in the range \([d_{0},d_{1}]\) to be detected, discrete smoothing scales \(\sigma_{n}\) are calculated as \(\sigma_{1}=d_{0}/4\), \(\sigma_{2}=r\sigma_{1}\), \(\sigma_{n}=r^{n-1}\sigma_{1}\) where \(r=(d_{1}/d_{0})^{\frac{1}{n-1}}\). The maximum dot value calculated among the different scales is chosen to be the final dot value for each voxel in the region. In this paper, \(n=3\) Gaussian scales are used. The feature is then the total number of voxels with dot value greater than \(T_{d}=5\).
# An Improved Routing Approach for Enhancing QoS Performance for D2D Communication in B5G Networks
## 4 Results and Discussion
### Energy Cost  
The energy cost simulation result of the routing schemes at various device speeds is depicted in Figure 10. The MBLCR obtains the lowest energy cost in the exchange of topological network information during the optimal path selection. The MBLCR incorporates the MCDM decision technique, which weighs and ranks the relay devices in the optimal path selection according to the devices' residual battery, thereby improving energy utilization during the data packet transmission. Moreover, the MBLCR exploits the ETX value prior to data transmission, which mitigates the flooding impact of RREQ messages and results in the minimization of device energy cost. From the perspective of device speed, it can be seen from Figure 10 that the MBLCR attains the lowest energy cost per packet in comparison to the counterpart routing approaches. The energy costs achieved by the MP-OLSRv2 are 24.34% and 20.14%, MEQSA-OLSRv2 are 22.48% and 19.64%, and the energy costs of the EMBLR are 16.85% and 15.26% higher than that of the MBLCR when the device speed increases from 10 m/s to 60 m/s.  
Figure 10: Energy cost with various device speeds.  
Figure 9: Energy consumption with various device speeds.
## 4 Experiment  
### Experimental System  
Based on the above theoretical analysis and derivation, we implemented the proposed adaptive anti-saturation synchronous control system using a dSPACE prototyping system and conducted experiments on the redundant direct-drive gantry platform to verify the improvement in the synchronous motion performance of the proposed method. Figure 6 shows the experimental setup. The Y-direction motion of the redundant direct-drive gantry platform was driven by AUM3 PMLSMs from Akribis. Each motor was equipped with RGS20-S grating from Renishaw, with a resolution of 0.1 \(\upmu\)m.  
The beam had a length of 836 mm, and its weight exceeded 25 kg, which caused the synchronous motion performance of the dual-motor system to be significantly affected by the synchronous control method. During the experiments, the dSPACE system controlled the PMLSMs in real time, and the feedback signals were provided by the gratings. By establishing the mathematical model of the motor system and using a frequency sweep experiment to identify the model parameters, the transfer functions of the motor systems were calculated as follows:  
\[\left\{\begin{array}{l}g_{y1}(s)=\frac{0.9183s^{3}+5.994s^{2}+8959s+8499}{s^{ 5}+16.92s^{4}+1.061e04s^{3}+7.916e04s^{2}+5.448e04s}\\ g_{y2}(s)=\frac{0.8818s^{3}+8.583s^{2}+8918s+2.223e04}{s^{5}+12.51s^{4}+1.104e04s^ {3}+3.237e04s^{2}+4.215e04s}\\ \end{array}\right., \tag{37}\]  
The dual-motor system adopted a proportional-integral-derivative (PID) feedback control method. According to the controlled object models shown in Equation (37), the Ziegler-Nichols tuning rules were used to obtain a set of PID parameters that were more consistent with the synchronous-motion requirements of the dual-motor system. The PID controller and its parameters are as follows:  
\[\left\{\begin{array}{l}c_{1}(s)=\big{(}27.41s^{2}+388.52s+1.05\big{)}/s\\ c_{2}(s)=\big{(}28.12s^{2}+275.44s+1.12\big{)}/s\\ \end{array}\right., \tag{38}\]  
Figure 6: Experimental system.
# Compact Quad-Port MIMO Antenna with Ultra-Wideband and High Isolation
## 3 Quad-Port UWB MIMO Antenna Design
### MIMO Antenna Structure  
The UWB antenna is used as a unit cell and the four cells are rotated symmetrically at the center by the polarization diversity technique, introducing four decoupled slits on the metallic ground to form the UWB MIMO antenna in Figure 8. The quad-port MIMO antenna is printed on the single side of the F4B substrate and the overall size is \(51.2\;\mathrm{mm}\;\times\;51.2\;\mathrm{mm}\;\times\;1.524\;\mathrm{mm}\).  
Figure 8: Structure of a four-cell MIMO antenna with polarization diversity.  
The layout of MIMO antennas with polarization diversity makes it easier to achieve high isolation, which is due to the fact that the antenna elements with linear polarization are perpendicular to each other, and the coupling is lower since the polarization methods between the elements are independent of each other. Without an additional decoupling device, a polarization diversity technique and a slit in the metallic ground state are used to reduce the coupling The effectiveness of this method is mainly due to the fact that the introduction of the slit destroys the integrity of the metal ground, changes the current transmission path, and to some extent truncates the coupling path of part of the current between the units, so the isolation degree can be improved.