esa-sceva/satcom-chunk-collection huggingface dataset:
## 7 Conclusions and Future Works  
A matricial version of the classical backward-forward power-flow method has been presented in this paper with the main advantage that it guarantees convergence under well-defined voltage conditions. In addition, numerical validations were performed using 33- and 69-node test feeders to demonstrate that the MBF proposal requires the minimum processing times as compared with those of classical methods such as GS, NR, and LM.  
The proof of convergence was performed by applying the Banach fixed-point theorem. This has permitted the conclusion that the proposed MBF method always converges under well-defined load conditions as the \(\theta\)-coefficient was defined as the relation between the maximum load current and minimum short-circuit current. This implies that \(\theta\) is always be comprehended between 0 and 1, thus guaranteeing the numerical convergence of the power-flow problem.  
The inclusion of voltage-controlled nodes was also considered by implementing a small four-node test feeder and comparing the numerical results reported using well-known software used for solving power-flow problems called DigSILENT and those of our proposed approach. The voltage profiles obtained using both these methods allowed use to conclude that the proposed MBF method can handle radial and meshed networks comprising VC nodes and will be suitable for multiple power-system applications shortly.  
Some additional works that can be derived from this work are listed below: (i) the application of this power-flow method to electrical networks comprising renewable energy sources and battery energy-storage systems in an embedded strategy that facilitates the optimal dispatch of these devices with metaheuristics; (ii) the application of our proposed approach for conducting optimal power-flow analyses in distribution networks via sequential programming approaches based on combinatorial optimization; (iii) the extension of the MBF formulation to electrical systems comprising hybrid structures that contain AC and DC feeders interfaced with power electronic converters.  
Conceptualization, O.D.M., and W.G.-G.; methodology, O.D.M., and W.G.-G.; formal analysis, O.D.M., and W.G.-G.; investigation, O.D.M., and W.G.-G.; resources, O.D.M., W.G.-G., and D.A.G.; writing--original draft preparation, O.D.M., and W.G.-G. All authors have read and agreed to the published version of the manuscript.  
This work was partially supported by the National Scholarship Program Doctorates of the Administrative Department of Science, Technology, and Innovation of Colombia (COLCIENCIAS), by calling contest 727-2015.  
The authors wish to confirm that there are no known conflicts of interest associated with this publication.
# Mechanical and Dielectric Properties of Aligned Electrospun Fibers
## 5 Electrospinning System for Dielectric and Mechanical Property Studies
### Tensile and Dielectric Test Results of Electrospun Mats  
PAN precursor with DMF solution at 8 wt.% concentration, using a 22G needle, is used for electrospinningnimg. More than thirteen experimental runs were carried out to determine suitable process parameter settings. The three best samples were taken, to analyze the degree of fiber alignment. The tensile and dielectric test results for the three samples are given below in Figure 23a-c. The SEM images are shown in Figure 24.  
Figure 21: (**a**) Fiber mat is being formed on mandrel. (**b**) Fiber mat on an aluminum foil [171].  
Figure 22: (**a**) Fiber mats using 18G needle magnified at 10 \(\upmu\)m and (**b**) using 22G needle magnified at 5 \(\upmu\)m [171].  
Figure 23: (**a**) Tensile strength of best three samples [171]. (**b**) Dielectric strength of best three samples [171]. (**c**) Tensile and dielectric properties of three samples [171].  
The SEM image of Sample 1 shows loosely packed nanofibers. Samples 2 and 3 have more closely packed fibers and better alignment of fibers, and Sample 3 has the highest densely packed fibers. These images are viewed at 20 \(\upmu\)m magnification. Tensile strengths of Samples 2 and 3 are better than that of Sample 1, since they are better aligned and closely packed. As evident from Figure 23a, Samples 2 and 3 show higher tensile strength, and Sample 1 has the least. Better alignment combined with dense fibers contributed to the better tensile strengths of Samples 2 and 3. Sample 2 shows a tensile strength of 4.47 MPa. As shown below, in Figure 23b, Sample 3 shows the highest dielectric constant. The dielectric constant for Sample 3 is 2.56 Hz at 0.1 Hz. The best parameters are chosen by comparing the results of Sample 1 with the best parameters.  
Figure 24: SEM images at 20 and 5 \(\upmu\)m of Samples 1, 2, and 3 [171].  
the three given samples for their SEM images, tensile strengths, and dielectric properties as shown in Figure 23c. Sample 3 gives consistent and uniform fibers. The best parameters at 8 wt.% correspond to Sample 3. The Sample 3 has uniform fiber distribution with the lowest range in diameters. Moreover, the fibers are formed without beads. The tensile strength and dielectric constant of Sample 3 is found to be 4.43 MPa and 2.56, respectively.
# Urban Traffic State Sensing and Analysis Based on ETC Data: A Survey
## 5 ETC-Based Urban Traffic Management: Applications and Practices
### Real-Time Monitoring and Signal Control Optimization
These technologies not only significantly improve traffic efficiency but also provide important technical reserves and application foundations for urban traffic management in future intelligent connected vehicle environments.
# Nonlinear Vibration and Post-Buckling Behaviors of Metal and FGM Pipes Transporting Heavy Crude Oil
## 1 Introduction
By enabling smooth transitions between metal and ceramic phases, FGMs can reduce interfacial stress concentrations and enhance resistance to thermomechanical loads. Despite their wide application in aerospace and nuclear sectors, their potential in oil transport pipelines remains underexplored, especially with regard to their nonlinear dynamic stability and post-buckling performance. This study aims to fill this gap by investigating the nonlinear vibration and post-buckling behavior of FGM pipes transporting heavy crude oil, thereby assessing their viability as a next-generation solution in the oil and gas industry. Consequently, it presents a unified and comprehensive nonlinear framework that, to the best of our knowledge, is the first to simultaneously examine the nonlinear vibration and post-buckling behaviors of temperature-dependent FGM pipes conveying heavy crude oil. In this context, two types of FGM pipes are considered: one with a metal-rich inner surface and ceramic-rich outer surface, and the other with the reverse configuration, comprising metal on the outside and ceramic on the inside. Also, the material properties of the FGM pipe are temperature-dependent. Therefore, by analyzing the mechanical and thermal performance of FGM-based pipes under various operating conditions, this study investigates the possibility of using them as a more reliable substitute. The novelty of this study lies in its unified treatment of nonlinear vibration and post-buckling behavior of FGM pipes conveying heavy crude oil, accounting for temperature-dependent material properties and two gradation configurations. Unlike previous studies, the model addresses realistic oil transport conditions involving high-viscosity fluids and thermomechanical interactions, offering new insights for pipeline design in harsh environments. To develop the nonlinear governing equations, we employ Timoshenko beam theory, which accounts for both rotary inertia and transverse shear deformation. These factors are especially significant for thick-walled or moderately thick FGM pipes where high stiffness gradients and thermal effects are present. Nonlinear strain terms are incorporated through [PERSON] assumptions, and [PERSON]'s principle is applied to derive the dynamic equations. The equations are discretized via [PERSON]'s method, and the nonlinear vibration behavior is investigated through the Runge-Kutta method. Furthermore, our validation (Section 6.1) against benchmark studies confirms the accuracy of the proposed formulation. Notably, the identified nonlinear vibration and post-buckling responses directly impact the structural integrity and operational reliability of FGM pipes transporting heavy crude oil in real-world applications.
# Enabling Technologies for Urban Smart Mobility: Recent Trends, Opportunities and Challenges
## 4 Smart Mobility Services and Applications
### Autonomous Vehicles
#### 4.4.3 Vehicle Communication Protocols  
Vehicular Ad-hoc Networks (VANETs) play a key role in intelligent transport systems (ITS). In VANETs, the development of a routing protocol for effective vehicular communications presents several challenges, which can be highlighted [87]:  
* Safe routing: the security of messages is, in all systems, delicate and of enormous importance. In this specific case, illegal message tampering can have very serious consequences and even have an impact on life-or-death situations;
* Reliable communication: link ruptures can suddenly happen due to some VANETs' characteristics such as high mobility, intermittent connectivity or obstacles in cities, and what to do in case of packet losses is a challenge;
* Determining the optimal path from a source to a destination, taking into account the density of traffic and the shortest distance;
* Determining a routing strategy that adapts to the two distinct environments of VANETs: city environment and motorways.  
The position-based routing protocol is considered one of the best approaches in VANETs [87] and can be adopted in an urban environment (where the biggest challenge is the obstacles) as well as on highways. In the literature and taking into account the challenges of routing in an urban environment, there are many proposals for the adoption of this type of protocol for communications V2V and V2I [88; 89; 90; 91; 92], with the various categories of protocols listed in Figure 8.
## 3 Lightweight Cryptography for Smart Objects
### Symmetric-Key LWC Algorithms
#### 3.1.4 Hight  
The HIGH security and light weigHT (HIGHT) encryption algorithm is a generalized Feistel network with a block size of 64 bits, 128-bit keys and 32 rounds [30]. HIGHT was designed with an eye on low-resource hardware performance. HIGHT uses very simple operations, such as XORing, addition mod \(2^{8}\), and bitwise rotation. The key schedule in HIGHT is designed so that subkeys are generated on the fly both in the encryption and the decryption phases.
# Parametric Analysis of Compliant End Face Gas Film Seals Considering Slip Flow Effects
###### Abstract  
Aiming at the compliant end face gas film seal structure, based on the linearized Boltzmann equation, the Poiseuille flow coefficient is introduced, and the generalized Reynolds equation and the sealing performance parameter solution formula considering the boundary slip flow effect are established. Through Newton-Raphson iterative calculation, the degree of influence of the slip flow effect under different working conditions is analyzed, and the internal relationship between structural parameters and sealing performance is compared. The results show that the slip flow effect can have a large impact on the pressure distribution in the fluid field close to the low-pressure side. Due to the existence of the step phenomenon of boundary velocity, it is not conducive to increasing the gas film opening force and controlling the mass leakage rate, but it can play a positive role in reducing the viscous friction power consumption. In the case of a smaller sealing gas film thickness and lower medium pressure, the slip flow effect is significant, which will have a greater impact on the sealing performance, and at this time, the slip flow effect can not be ignored. In addition, the change in seal structure parameters will also have a large impact on the sealing performance. With an increase in the wave foil thickness, the compliant end face evolves towards the rigid end face, the fluid wedge effect is weakened, and the gas film opening force and mass leakage rate are reduced. The stiffness-to-leakage ratio shows a strong nonlinear decreasing trend with an increase in the wave foil chord length and pitch, which eventually tends to a stable value. The results of this paper provide a theoretical basis for the matching design of the structural parameters of compliant end-face gas film seals under different service conditions.  
slip flow effect; compliant end face; dry gas sealing; finite difference method; performance
# Design of W-Band GaN-on-Silicon Power Amplifier Using Low Impedance Lines
## 2 Design of W-Band Power Amplifier in GaN on Si HEMTs
### Design of W-Band Three-Stage Power Amplifier
It is confirmed by Figure 4c that each stage provides almost equal gain around 5.0 dB at low input power, where \(\text{P}_{\text{out1}}\), \(\text{P}_{\text{out2}}\), and \(\text{P}_{\text{out3}}\) are the powers produced by each stage at the drain. This figure also indicates that the final stage is the first to saturate and produces nearly 3-dB higher power than 2 nd stage as expected from the gate width ratio. These results confirm that each stage is properly designed to have enough power gain and output power. Figure 3: Design of final stage (two 100 \(\upmu\)m-wide HEMTs in parallel). (**a**) Circuit schematic. Impedance trajectories of (**b**) output matching and (**c**) input matching networks from 88 to 92 GHz. Gate and drain bias circuits are designed using the quarter-wave long (\(\lambda_{g}/4\)) lines with shunt capacitors which are attached to the low-\(Z_{0}\) lines used for impedance matching, as depicted in Figure 4a. The low-frequency stabilities improved by introducing resistors and capacitors in the gate bias lines. In order to suppress the odd-mode oscillations, the resistor \(\mathrm{R_{odd}}\) was inserted between two gate terminals of the final stages. To double the output power, two of the three-stage power amplifier in Figure 4a were combined using Lange couplers as shown in Figure 5a. The width, spacing, and length of the coupled lines in the Lange coupler were optimized to have an equal power division with a minimum loss and 90\({}^{\circ}\) phase difference between two output ports, which is essential to achieve high combining efficiency and good input/output return losses [16]. The isolation was also considered in the design of the Lange coupler to minimize the coupling between two amplifiers, which improves the stability of the entire amplifier [17]. The designed final amplifier exhibits the simulated gain of 14.4 dB with good input and output return loss as shown in Figure 5b. The saturated output power was simulated to be 29.4 dBm with a PAE of 15.4% at 90 GHz as in Figure 5c. There are many low-impedance microstrip lines with very wide signal widths in the designed power amplifier, generating the discontinuities between other components such as narrow-width lines or DC-blocking capacitors. Therefore, a 2.5-dimensional electromagnetic (EM) simulation was carried out using a commercial simulation tool (Momentum in the Keysight Advanced Design System) to optimize the dimensions of the microstrip lines. Figure 4: Design of three-stage power amplifier. (**a**) Circuit schematic. (**b**) Load impedance of each stage of designed amplifier (from 88 to 92 GHz) on top of load-pull contours at 90 GHz. (**c**) Simulated output power of each stage as a function of input power at 90 GHz.
# Statistical Modeling of NaCl and FeSO4 Pretreatment Effect on Refractory Copper Ore Leaching
## 3 Results and Discussion
### Multiple Regression Modeling of Sulfation  
The multiple regression model fitted from the experimental design is shown in Equation (8):  
\[\begin{array}{ll}y=-17.368309&+1.028948x_{1}+0.214509x_{3}-0.013451x_{1}^{2}+0.0 0339x_{2}^{2}-0.005783x_{3}^{2}+0.002214x_{1}x_{3}\\ &+0.000049x_{1}^{3}+0.000027x_{3}^{3}-0.000156x_{4}^{3}+0.000014x_{1}^{2}x_{2} -0.000045x_{1}x_{2}x_{3}\\ &-0.000091x_{2}^{2}x_{4}+0.000028x_{2}x_{3}^{2}+0.000236x_{2}x_{4}^{2}+0.00001x_ {3}^{2}x_{4}\end{array} \tag{8}\]  
ANOVA analysis indicates that the model fitted in Equation (8) adequately represents sulfation under the set of parameters sampled. The model requires no additional adjust  
Figure 4: Individual confidence intervals for the differences in the means of the different levels and residuals plot of the models for the independent variables AAC (**a,b**); NaCl (**c,d**); and FeSO\({}_{4}\) (**e,f**).  
ments and is validated by the goodness-of-fit statistics shown in Table 3, although the statistics, \(p\)-values (\(p\leq 0.05\)), and R\({}^{2}\) (72.72%) indicate that the model is statistically significant (see Tables 3 and 4). Nevertheless, enhancements in the model's fit may be attainable through the expansion of the sample size or the incorporation of additional variables that could impact the response. Furthermore, the F-test substantiates the statistical significance of the fitted model.  
The analysis of the standardized residuals derived from the model specified in Equation (8) indicates that they conform to a normal distribution, as illustrated in Figure 5. This conclusion is supported by the \(p\)-value obtained from the hypothesis test, which is 0.414. Since this \(p\)-value is more significant than the significance level, it confirms the normality of the residuals (\(\alpha=0.05\)).  
\begin{table}
\begin{tabular}{c c c} \hline \hline \(\mathbf{R^{2}}\) & \(\mathbf{R^{2}}\) (Adjust.) & \(\mathbf{R^{2}}\) (Predict.) \\ \hline
72.72\% & 70.90\% & 68.51\% \\ \hline \hline \end{tabular}
\end{table}
Table 4: Model summary adjusted in Equation (8).  
Figure 5: Standardized residuals plot (**a**) and normality test (**b**) of the fitted model in Equation (8).  
The surface plot modeling the response suggests that sulfation exhibits an increase at low to intermediate levels of the sampled parameters. The analysis indicates that maximum sulfation is attained at approximately 60 h across all time combinations (refer to Figure 6a-c).  
Figure 6: Response surface plot for sulfation versus: time and ACC (**a**); time and NaCl (**b**); time and FeSO4 (**c**); AAC and NaCl (**d**); AAC and FeSO4 (**e**); and NaCl and FeSO4 (**f**).  
In contrast, the response plots illustrated in Figure 6d-f demonstrate a corresponding increase in sulfation when the other independent variables examined occur in elevated levels. A directly proportional relationship is observed between the percentage of sulfation and the variables ACC, NaCl, and FeSO\({}_{4}\).
# MLKD-Net: Lightweight Single Image Dehazing via Multi-Head Large Kernel Attention
## 6 Discussion  
The proposed MLKA adopts a channel splitting strategy, whereas conventional multi-head approaches typically allow all heads to process the full input feature map. However, the results of Experiment 5.1.2 demonstrate that designing a scalable architecture--where the performance consistently improves with increased parameters--remains a challenging problem, particularly in convolution-based structures. In many cases, an increase in parameters does not lead to proportional improvements in performance. From this perspective,  
\begin{table}
\begin{tabular}{l c c c} \hline \hline \multirow{2}{*}{**Method**} & **SOTS-Outdoor** & \multirow{2}{*}{**Method**} & **SOTS-Outdoor** \\  & **PSNR** & & **PSNR** \\ \hline Split-H1-T No Shuffle & 35.67 & Split-H1-T & 35.71 \\ Split-H2-T No Shuffle & 35.54 & Split-H2-T & 36.03 \\ Split-H4-T No Shuffle & 35.07 & Split-H4-T & 35.49 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Performance comparison of MLKD-Net with and without the Channel Shuffle block.  
Figure 6: Performance comparison of MLKD-Net with different numbers of expanded heads. The configurations Expand-H1, Expand-H2, and Expand-H4 correspond to models with 1, 2, and 4 attention heads, respectively, using a channel expansion strategy.  
the splitting-based MLKA mechanism emerges as a competitive and efficient alternative, especially in scenarios where lightweight design is critical.  
Thanks to its lightweight architecture and fast inference capability, MLKD-Net is highly suitable for real-time applications on resource-constrained platforms such as mobile devices, drones, and embedded systems like the NVIDIA Jetson series. In addition, the proposed MLKA mechanism is expected to provide performance gains when applied to a variety of low-level vision tasks, including deraining, denoising, and image enhancement.
## 1 Introduction
### Cross Laminated Timber (CLT) and Its Development as a Sustainable Material
#### History and Basic Information of CLT  
As a novel material on the building market, cross-laminated timber (CLT) was first produced in Central Europe in the 1900s [33]. The CLT patent was first registered in 1985 in France, and was propagated widely in the 1990s in Germany and Austria [34], but other European countries did not appear to take it up [25]. Although lacking detailed regulation, the material was utilized in several new applications in architecture and structural engineering with the development of CLT structural technology [35]. Following the widespread use of CLT in the building industry over the last decade, the European Cooperation in Science and Technology (COST) published design codes for buildings with CLT structures in 2018 [33].  
CLT is composed of odd number staggered wood layers (usually three, five or seven layers) (Figure 1), for the purpose of achieving structural stability by resisting out of plane loads, with different layers of timber boards are placed in different directions [36]. Due to a lack of unified product standards, CLT panels are produced in various dimensions by different manufacturers. The thickness of a CLT panel can be up to 500 mm. Typical widths are 600, 1200, 2400, and 3000 mm and lengths are typically 18,000 mm or even longer depending on the building project [37]. Due to their high mechanical performance, CLT panels can be used as structural elements in buildings such as load bearing walls, floors, and roofs, and non-load bearing partitions [38]. As the majority of the CLT panels are prefabricated in factories, onsite construction can be completed within 3 to 4 days in some cases [39].