esa-sceva/satcom-chunk-collection huggingface dataset:
## 6 Conclusions  
In this paper, a straightforward technique which is a partially non-linear approach has been developed from SM to analyze geometrically non-linear structures. A comparison has been made among the current technique, SM, and the two non-linear quoted methods to evaluate the accuracy of the proposed approach. The outcomes are:  
* The results of the proposed technique are in good agreement with the non-linear techniques' ones, with a slight discrepancy, while the dissimilarity between of the nodal displacements of SM and the quoted non-linear methods is 228%;
* It can be concluded that the proposed technique is accurate and applicable for geometrically non-linear structures;
* The accuracy of the technique is enhanced by increasing the number of iterations; however, the number of iterations could be assumed to be 15 to get reasonable results.  
**Author Contributions:** Modeling and analysis, N.S.; writing the first draft, A.M.; reviewing, M.S.; supervisor, R.J. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{l l l l l} \hline \hline \multirow{2}{*}{**Joint**} & \multirow{2}{*}{**Direction**} & \multicolumn{2}{c}{**Methods**} & \\ \cline{3-5}  & & **SM (mm)** & **Current Study (mm)** & **[PERSON] et al., (1984) (mm)** \\ \hline \multirow{2}{*}{2} & x & 0 & \(-\)6.05 & \(-\)6.01 \\  & Y & \(-\)135 & \(-\)134.64 & \(-\)134.05 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Analysis of the cantilever beam using several techniques.  
Figure 10: Cantilever beam under vertical loading.
## 6 Experimental Result  
To verify the feasibility of proposed LQRIC, a 110 V-5 kVA three-phase four-wire \(LC\)-HAPF experimental prototype was constructed and is shown in Figure 7. A digital signal processor TMS320F2812 is applied and works in a 10 kHz sampling frequency. The Mitsubishi IGBT intelligent power module PM300 DSA60 is used as the power switch in the VSI.  
Figure 7: Experimental prototype of 110 V–5 kVA \(LC\)-HAPF.  
This paper takes IEEE Standard 519-2014 [31] as a reference. At small experimental rated 110 V-5 kVA prototypes and \(I_{SC}\)/\(I_{L}\) in the range of 100 < 1000 scale, the acceptable total demand distortion (TDD) is less than or equal to 15%. Considering the worst case, the rated current is equal to the fundamental load current and results in THD = TDD \(\leq\) 15%. Therefore, THD \(\leq\) 15% is used as a criterion to evaluate the \(LC\)-HAPF current harmonic compensation performance.  
The experimental results before and after the \(LC\)-HAPF compensation with LQRC and LQRIC under 50V and 40V DC-link voltage conditions are shown in Figures 8 and 9 and Table 4.
## 3 Experimental Setup  
Figure 2 shows the schematic for the low-noise laser system. The fiber amplifier is seeded by a low-noise, narrow-linewidth (<1 kHz), single-frequency Nd:YAG NPRO emitting at 1064.35 nm with an output power of 100 mW injected into the fiber amplifier via an optical fiber isolator (ISO) to avoid any possible backscattered light and stimulated Brillouin scattering (SBS) light in the amplifier.  
The fiber amplifier uses a 2.5 m long Yb-doped polarization-maintaining fiber (Nufern, PLMA-YDF-10/125, CA, USA) forward-pumped by a wavelength-stabilized pump-diode module (BWT, K976 AA2 RN, Beijing, China) operating at 976 nm, which can deliver up to 18 W of CW power at the maximum current of 11 A. The active fiber has a core/cladding diameter of 10/125 \(\upmu\)m and a core numerical aperture of 0.08, making it single-moded at 1064 nm. It has a cladding absorption of 4.9 dB/m at 976 nm. The forward-pump scheme  
Figure 2: Schematic for the low noise fiber amplifier. ISO: isolator, YDF: Yb-doped fiber, CPS: cladding power stripper, MM Pump LD: multi-mode pump laser diode. Red line and black line represent laser signal path and electrical signal path respectively.  
is employed to minimize potential feedback and possible catastrophic damage. After cladding power stripper (CPS) and fiber isolator, the amplified laser is divided into two laser beams (1% for feedback and 99% for out-of-loop test) by a fiber splitter. The 1% laser beam was attenuated and detected by a low-noise photodetector (PD\({}_{\text{in}}\)). The output of the PID controller (SRS, SIM 960, Santa Clara, CA, USA) is used to control the pump LD current in real time. The second fiber splitter (1:99) is employed for out-of-loop noise evaluation. It is worth noting that all the components involved are in polarization-maintaining fiber format to have excellent long-term mechanical stability and maintenance-free operation. The fiber amplifier and the feedback loop are placed in an aluminum alloy box with good vibration isolation and good temperature stabilization.
# Controllable Fano-like Resonance in Terahertz Planar Meta-Rotamers
## 3 Results and Discussion
When the two standing wave antinodes were not aligned, the combined effect of the C- and Y-shaped meta-atoms appeared as a simple summation of each resonance without a significant change in the resonant frequency, as shown by the red circles in Figure 4a. On the contrary, the clear red-shift of the second-order LC resonance was visible because of the strong coupling when the standing wave antinodes were placed opposite to each other,  
Figure 3: **(a,c,e)** Simulated THz amplitude spectra in the meta-rotamers consisting of the C-shaped SRR and Y-shaped rod meta-atoms, for the two different states of the meta-rotamers with rotation angles of \(\theta_{y}=0^{\circ}\) and \(60^{\circ}\), as shown by the black and red solid lines, respectively. Each THz amplitude spectra were simulated in the three types of samples with different angular gaps of \(\theta_{c}=10^{\circ}\), \(20^{\circ}\), and \(30^{\circ}\), as shown in **(a,c,e)**, respectively. **(b,d,f)** Spatial electric near-field distributions for the meta-molecules at the resonances of \(f_{1}\), \(f_{2}\), \(f_{1}^{\prime}\) and \(f_{2}^{\prime}\). For the three types of samples with different angular gaps of \(\theta_{c}=10^{\circ}\), \(20^{\circ}\), and \(30^{\circ}\), \(f_{1}=0.63\), \(0.65\), and \(0.66\) THz, \(f_{2}=0.74\), \(0.74\), and \(0.74\) THz, \(f_{1}^{\prime}=0.66\), \(0.68\), and \(0.70\) THz, and \(f_{2}^{\prime}=0.73\), \(0.73\), and \(0.73\) THz, respectively. as quantitatively compared in Figure 4b, which shows the values of resonant frequency shift, \(\Delta f_{1}=f_{1}-f_{1}\) and \(\Delta f_{2}=f_{2}^{\prime}-f_{2}\). The coupling strength is important in achieving resonance characteristics such as a high Q-factor. As shown in Figure 4c, the Q-factor exhibits an interesting growth behavior with the increase of the angular gap showing higher coupling strength between the two resonances. Here, if the coupling strength is increased by approximating the two resonances in the spectrum, a larger Q-factor can be expected. Although we expected to maximize the Q-factor and the resonance strength, there was a tradeoff between these factors, which is a typical characteristic of the resonance phenomenon, as shown in the values of resonance depth (blue squares). On the contrary, the Q-factor and resonance depth extracted from the dipole resonance of the Y-shaped rods exhibited a slight difference by varying the angular gap. Thus, the asymmetric feature of the Fano-like resonance caused by the strong coupling between each resonance of two different types of meta-atoms suggests a method to control the resonant frequency and the Q-factor.
# Evaluation of Rural Visual Landscape Quality Based on Multi-Source Affective Computing
### Summary of Relevant Research  
In summary, the primary challenges in rural visual landscape affective computing research are as follows: (1) Insufficient interdisciplinary integration in rural landscape affective computing. Although affective computing technology has been extensively applied in fields such as healthcare, education, and urban design, its comprehensive integration into rural landscape visual quality assessment remains underdeveloped. (2) Limited collaborative classification of multimodal data and subjective questionnaires. While the fusion of objective modes, such as eye tracking and EEG, has been explored in multi-source affective computing, few datasets have been developed that use subjective questionnaire data as independent variables. (3) Existing studies lack systematic verification of the adaptation rules for classifier performance. Most research defaults to using a single classifier (e.g., SVM or Random Forest) to process emotion classification tasks across various categories, overlooking the boundary effects of task complexity on model performance. This leads to challenges such as difficulties in adaptive multi-source feature fusion, weak scene generalization, and small sample overfitting. In response, this study selected twelve rural landscape images, representing four distinct types from Dalian, Liaoning, China, as stimuli. It collected emotional signals using a combination of subjective and objective methods (\"eye movement + EEG + questionnaire score\") from participants, and applied machine learning and ensemble learning techniques to develop an emotion classification model and spatial emotion quality assessment process. This approach is applicable to a variety of rural visual landscape quality assessments, with the final evaluation results providing valuable insights for rural landscape design and decision-making in rural revitalization.  
This paper is structured into five sections: Section 1 provides an overview of the prior research. Section 2 introduces the study area, data, and methodologies employed. The key findings are presented and analyzed in Section 3. Section 4 discusses the results, along with the study's limitations. Finally, Section 5 presents the conclusions.
## 3 Calibration System and Improved Speckle Statistics
### Improved Speckle Statistics
We assumed that the scattering field was a circular complex Gaussian variable and that the cross-correlation function of the scattering field between two wavelengths separated by \(\Delta\lambda\) is given by  
\[\big{\langle}E^{*}(\lambda)E(\lambda+\Delta\lambda)\big{\rangle}\propto\int_{- \infty}^{\infty}A^{2}(z)\exp\biggl{(}-i\frac{4\pi z\Delta\lambda}{\lambda} \biggr{)}dz, \tag{10}\]  
where \(E(\lambda)\) is the field at wavelength \(\lambda\) backscattered from a one-dimensional scatter, \(\Delta\lambda\) is the wavelength separation between on and off wavelengths, and \(A\) is the scattering amplitude at each point and is taken to be a Gaussian profile. The normalized field correlation function is expressed as:  
\[\rho_{E}(\Delta\lambda)=\exp\biggl{[}-4\pi^{2}\biggl{(}\frac{L}{\lambda} \biggr{)}^{2}\biggl{(}\frac{|\Delta\lambda|}{\lambda}\biggr{)}^{2}\biggr{]}, \tag{11}\]  
Figure 9: Standard deviation \(\sigma_{I}\) of the normalized intensity ratio as a function of the smoothing time with different correlation coefficients. where \(L\) is the 1/e radius of the intensity. Then, \(\rho_{E}(\Delta\lambda)\) is equal to s\({}^{2}\), by virtue of the Siegert relation. We assumed that the effective target depth was a constant, and so a small \(\Delta\lambda\) results in a high correlation. This reminds us to select the wavelengths with a small wavelength separation between on and off, providing the potential for improving the precision of the IPDA system. As detailed in Section 4, laboratory experiments were designed to verify the theoretical analysis above.
## 3 Experimental Results and Analysis
### Effect of Water Content on the Breakdown Characteristics of Oil in the Nanotransformer
Compared to oil samples with low water contents, when the water content was relatively high, within the experimental temperature range, TiO\({}_{2}\)-nanomodified transformer oil exhibited a smaller magnitude of enhancement in breakdown voltage compared to pure oil but a higher percentage increase. In addition, it can be observed that nanoparticles had a certain enhancing effect on the breakdown voltage of transformer oil. The breakdown process of transformer oil under the action of power frequency AC electric field can be regarded as the development process of streamer in the oil. The influence of nanoparticles on electron migration weakens the electron collision ionization process. On the one hand, the role of shallow traps accelerates the escape of electrons from the ionization region. When free electrons migrate at high speed, they are prone to ionization due to collisions with liquid molecules. The addition of nanoparticles introduces a large number of shallow traps, which capture free electrons and make them more likely to jump between adjacent traps, prompting electrons to escape from the ionization region. The escaped electrons are either neutralized or form negative ions, thereby weakening the repeated collision ionization process caused by electrons in the ionization region and suppressing the initiation of electron avalanche [51]. On the other hand, the polarizing trapping effect of nanoparticles reduces the number of electrons in the ionization region. Under the action of an external electric field, nanoparticles undergo polarization, and the positively charged region induced on the surface of nanoparticles captures high-speed moving electrons, forming negatively charged nanoparticles with slow movement speed. In this way, while reducing the electric field intensity in the oil, it also slows down the movement rate of positive and negative charges, thereby increasing the breakdown voltage and breakdown time.
# Accurate Estimation of Air Pollution in Outdoor Routes for Citizens and Decision Making
## 5 Results  
In this section, we show our results using three different types of tests in order to evaluate the pollution distribution over a selected route. In particular, we will analyse: (a) evolution over 24 h in 2 h steps, (b) impact taking into account different transport modes, and (c) behaviour of the different pollutants. We must highlight that our goal is to check how this system performs in order to estimate pollution in different scenarios on different routes, and not to analyse how the pollution itself behaves. For simplicity, the routes have been selected using the shortest path criteria between an origin and destination with different modes as indicated, whether walking or cycling. Over these routes, we assess the pollution information that is provided to the user. We evaluate the application in the city of Valencia (Spain) as depicted in Sections 3.2 and 3.3.  
The colouring scale of the maps shown in this section to identify the pollutant concentration is based on the maximum acceptable value indicated by the WHO as follows: the green colour is assigned if the value is below 50% of the maximum acceptable value, yellow if it is between 50 and 75%, orange if it is between 75 and 100%, and finally red if it is above the maximum acceptable value.  
Figure 4: Flowchart of the citizen application to check air pollution on his/her outdoor routes.
## 2 [18F]Fluoride Activation for Aliphatic Nucleophilic S\({}_{\text{N}}\)2 Substitution  
Aliphatic nucleophilic S\({}_{\text{N}}\)2 substitution in the presence of K\({}_{2,2,2}\)/K\({}_{2}\)CO\({}_{3}\) or Bu\({}_{4}\)NHCO\({}_{3}\) is currently the most prominent method for the production of the majority of clinically relevant radiotracers, including [18F]FDG, 3-deoxy-3-[18F]fluorothymidine ([18F]FLT), [18F]fluoromisonidazole (1-[18F]fluoro-3-(2-nitroimidazol-1-yl)-propan-2-ol; [18F]FMISO), \(O\)-(2-\({}^{\prime}\)[18F]fluoroethyl-L-tyrosine ([18F]FET), 16\(\alpha\)-[18F]fluoroestradiol ([18F]FES) (Figure 1), and others [2; 5; 6; 7; 8; 9; 10; 11; 12].  
Typical one-vessel two-step synthesis of a radiotracer is achieved by nucleophilic displacement of an appropriate leaving group in the precursor with activated [18F]F\({}^{-}\) in polar aprotic solvents (MeCN, DMF, DMSO, etc.) at 80-130 \({}^{\circ}\)C followed by (if necessary) removal of the protective groups. This methodology was also adapted to the labeling of a number of 18F-labeled bioactive and drug-like molecules prepared via direct radiofluorination, as well as for the preparation of the most common 18F-fluoroalkylating agents [14] and prosthetic groups [15] for indirect radiolabeling approaches. Despite the fact that conventional azeotropic-drying methodologies are well established in the aliphatic fluorinations and are implemented in the majority of automated synthesizers, the drying-free approaches have shown distinct advantages such simplicity of the automation and shorter production time.  
Traditionally the methods to circumvent the drying process relied upon the variation of the composition of kryptofix-based AEC eluent containing either K\({}_{2}\)CO\({}_{3}\) or less basic KHCO\({}_{3}\), K\({}_{2}\)C\({}_{2}\)O\({}_{4}\), and reduction of water fraction in the organic/water mixture. For base-sensitive precursors encouraging results were achieved using chemically inert quaternary ammonium salts such as Bu\({}_{4}\)NOTs, Bu\({}_{4}\)NOTf, and Et\({}_{4}\)NOTf that have been introduced recently _in lieu_ of \"classical\" Bu\({}_{4}\)NHHCO\({}_{3}\).  
Figure 1: The structures of the commonly used tumor seeking agents prepared by conventional aliphatic radiofluorination.
## 3 Key Technologies of UAV-Assisted SAGINs
### Routing Protocols
#### 3.1.2 Proactive Routing Protocols
Due to each node having the latest routing table, when a data packet needs to be sent, the node can immediately determine the optimal path to reach the destination node, thereby reducing routing latency. The extended ELM model has shown to be effective in processing large-scale data with high accuracy and fast calculation speed, which is crucial for the dynamic and real-time communication needs of UAVs and other components in SAGINs. Proactive routing protocols provide fast routing decisions, which are of significance for the dynamic and real-time communication needs of drones. However, in highly dynamic network environments, these protocols face challenges such as frequent topology changes and the high mobility of nodes. To address these challenges, researchers have proposed various optimization strategies [PERSON] et al. [19] proposed a hybrid SDN-based architecture to implement secure and QoS-aware routing in SAGINs, utilizing multiple SDN controllers at different levels to find multiple routes that meet security and QoS requirements. [PERSON] et al. [56] developed deep learning-assisted routing algorithms to utilize quasi-predictable network topologies and operate in a distributed manner, improving coverage quality by reducing end-to-end latency and increasing end-to-end throughput. In addition, in order to achieve the global optimization of resources in large-scale networks and collaboration between heterogeneous networks, [PERSON] et al. [57] proposed a multi-controller deployment strategy based on a simulated annealing algorithm for 6G SAGINs supporting SDN, aiming to balance controller load and improve network performance. These strategies emphasize the integration of advanced technologies such as SDN and deep learning to improve the efficiency and adaptability of active routing protocols in SAGINs' complex dynamic environment.
## 4 Results and Discussion
### Frost Heave Simulation
The horizontal displacement of the ground surface increases initially with increasing distance from the tunnel's center until it reaches a maximum value of 7 m, at which point it starts to decrease. The distribution of frost heave displacement from the top of the tunnel to the surface is shown in Figure 13. The soil displacement at the top of the tunnel is the largest, the freezing displacement decreases with decreasing distance from the surface, and the surface displacement is the smallest. Figure 11: Surface vertical displacement distributions. Figure 10: Horizontal displacement of the soil: (**a**) freezing for 10 days; (**b**) freezing for 20 days; (**c**) freezing for 30 days; (**d**) freezing for 40 days. A comparison of the frost heave displacement monitoring values of the vertical displacement of the ground surface directly above the center of the tunnel for the first 20 days with the simulated values is shown in Figure 14. The figure confirms a strong correlation between the field results and the numerical simulation. This indicates that the application of this numerical simulation method for the analysis of the effect of artificial frozen soil on the displacement of the surrounding soil is accurate and consistent and can feasibly be used in theoretical and practical simulations. The displacement in the measured data shows a tendency of decreasing and then increasing, which occurs because the surface where the freezing project is located is an urban arterial road, on which there is often a vehicle load, resulting in a decreasing trend in the measured results. So, the method still needs some small refinements, as shown in Figures 7 and 8. Figure 14: Frost heave displacement comparison between simulation and actual measurement. Figure 6:0 Surface horizontal displacement distributions. Figure 6:1 Soil frost heave displacement map directly above the tunnel.
###### Abstract  
This study proposes and evaluates a two-step phosphorus (P) recovery strategy that combines chemical precipitation with adsorption to comply with the updated EU Urban Wastewater Treatment Directive (Directive (EU) 2024/3019), which sets stricter limits on nutrient discharge and promotes resource recovery. The objective was to enhance the P removal efficiency beyond that achieved by conventional precipitation. A laboratory-scale design of experiments was conducted using real wastewater with an initial P concentration of 10 mg P/L post-precipitation and was extended to 1 and 40 mg P/L to assess broader applicability. The optimal lab-scale conditions (30 cm bed height and 5 mL/min flow rate) resulted in a saturated bed fraction (_FSB_) of 0.425 and a breakthrough time of 126 min. The process was successfully scaled up to a column with a height of 60 cm and a diameter of 4 cm, achieving a higher _FSB_ (0.764), improved adsorption capacity (84.1 mg P/kg), and reduced unused bed (40%). The integrated system maintained effluent P levels below 0.5-0.7 mg P/L for over 400 min, demonstrating regulatory compliance and operational reliability. These findings confirmed the feasibility and scalability of combining precipitation with adsorption for enhanced P recovery in wastewater treatment systems.  
adsorption; dynamic studies; phosphorus; calcined eggshell; wastewater treatment plants