esa-sceva/satcom-chunk-collection huggingface dataset:
## 6 Results and Discussion
### Case 1. Uniform Irradiance Condition  
All the modules of the PV system received the same irradiance level in this case and it changes with respect to time. The irradiance pattern is described in Table 2. Figure 7 presents the PV energy systems UI curves of P-V and I-V. The pattern of uniform irradiance that is taken is elaborated in Table 2.  
When comparing the power of different techniques, it is observed that the power at GM is 864 W and the highest power tracked at \(700(\frac{KW}{m^{2}})\) irradiance level is 863.4 W in case of uniform irradiance condition for proposed hybrid (InC-DFO) technique. While comparing the power of all techniques, FA has the lowest power 852 W. The tracked power in the sequence is as follows: \(Hybrid>DFO>InC>CS>ACO>PSO>FA\). CS algorithm has more oscillation and the highest setting time of 1.94 s. Among all the techniques, FA tracked the least power of 852 W. The proposed hybrid technique saves power loss by reducing the oscillation and enhancing the efficiency of 99.93% of PV energy systems. CS has the highest oscillations that cause power loss when compared to other techniques.  
Figure 9: Simulation Model.  
To reduce the oscillation, the value of step size could be reduced that can cause increases in tracking time. The range of step size of the DC to DC boost converter should be between 2 to 5 percent of PV arrays power to balance the efficiency and tracking time. In CS, levy flight causes large fluctuations. It is determined that among all the techniques, the hybrid technique has the largest efficiency, no oscillations, fast-tracking time, least convergence time of 0.50 s, and settling time of 0.59 s.
###### Abstract  
Currently, X-ray photoelectron spectroscopy (XPS) is widely used to characterize the nanostructured material surface. The ability to determine the atom distribution and chemical state with depth without the sample destruction is important for studying the internal structure of the coating layer several nanometers thick, and makes XPS the preferable tool for the non-destructive testing of nanostructured systems. In this work, ultra-soft X-ray spectroscopy methods are used to study hidden layers and interfaces of pyrolytic tungsten carbide nanoscale coatings on the multi-walled carbon nanotube (MWCNT) surfaces. XPS measurements were performed using laboratory spectrometers with sample charge compensation, and Near Edge X-ray Absorption Fine Structure (NEXAFS) studies using the Russian-German dipole beamline (RGBL) synchrotron radiation at BESSY-II. The studied samples were tested by scanning and transmission electron microscopy, X-ray diffractometry, Raman scattering and NEXAFS spectroscopy. It was shown that the interface between MWCNT and the pyrolytic coating of tungsten carbide has a three-layer structure: (i) an interface layer consisting of the outer graphene layer carbon atoms, forming bonds with oxygen atoms from the oxides adsorbed on the MWCNT surface, and tungsten atoms from the coating layer; (ii) a non-stoichiometric tungsten carbide WC1-x nanoscale particles layer; (iii) a 3.3 nm thick non-stoichiometric tungsten oxide WO3-x layer on the WC1-x/MWCNT nanocomposite outer surface, formed in air. The tungsten carbide nanosized particle's adhesion to the nanotube outer surface is ensured by the formation of a chemical bond between the carbon atoms from the MWCNT upper layer and the tungsten atoms from the coating layer.  
XPS; NEXAFS; TEY; MWCNT; WC1-x/MWCNTs; MOCVD 2020
# Optimization of a Multi-Type PMSM Based on Pyramid Neural Network
## 5 Conclusions  
This paper systematically studied the QBA optimization method combined with a PNN model for the structure optimization problem of HPMSMs. The PNN models for the objective functions of the loss and torque were proven to be sufficiently accurate to replace the FEM simulation. Instead of calculating an FEM simulation for each particle, applying PNN models could shorten the working time of the optimization process.  
In this paper, a fast prediction model of electromagnetic field distribution based on PNN was studied. Based on the rapid predictive neural network model, the structure of permanent magnet synchronous motor was optimized globally, and the optimal motor structure parameters were obtained, so that the designed permanent magnet synchronous motor could achieve a good performance. The correctness of the model was verified using a finite element simulation and prototype test.  
The research content and conclusion of this paper are as follows:  
1. An efficient modeling method based on PNN deep learning was studied. This method constructed the mapping relationship between input structure parameters and the performance of the PMSM. It was able to solve the problem of rapid electromagnetic field prediction in the optimal design of PMSM.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Speed** & **Current** & **Simulation Results of Torque** & **Experiment Results of Torque** \\
**(krpm)** & **(A)** & **(N-M)** & **(N-M)** \\ \hline
20 & 20.4 & 1.055 & 1.1 \\
30 & 20 & 1.026 & 1.0 \\
40 & 20 & 1.026 & 1.0 \\
50 & 20.5 & 1.055 & 1.1 \\
60 & 20.5 & 1.055 & 1.1 \\ \hline \end{tabular}
\end{table}
Table 7: Comparison of electromagnetic torque under different phase current.  
Figure 12: Structure of the prototype. (**a**) Rotor. (**b**) Stator.  
2. The QBA optimization algorithm was used to determine the optimal structural parameter combination of permanent magnet synchronous motors and obtain the best performance.
3. The experimental results of the prototype showed that this method is effective and advanced for the structural optimization design of HPMSM.  
Conceptualization, X.L.; methodology, X.L.; software, W.P.; validation, L.X., W.P. and X.Z.; formal analysis, X.L.; investigation, X.Z.; resources, W.P.; data curation, L.X.; writing--original draft preparation, X.L.; writing--review and editing, X.L.; visualization, W.P. and X.L.; project administration, X.L.; funding acquisition, X.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Science and Technology Research Program of Chongqing Municipal Education Commission under grant number KJQN202200543.  
Not applicable.  
The data are not publicly available due to [3 rd Party Data Restrictions apply to the availability of these data].  
The authors declare no conflict of interest.
# A Novel Approach for the Estimation of Doubly Spread Acoustic Channels Based on Wavelet Transform
## 4 Simulation Results  
### Performances  
In this part, we use computer simulations to evaluate the performance of the proposed WT-based algorithm, and comparisons with OMP algorithm will also be included.  
The parameters of the transmitted superimposed HFM signal are set as follows: the starting frequency and end frequency are \(f_{1}=6\,\mathrm{kHz}\), and \(f_{2}=10\,\mathrm{kHz}\). The time duration is set to be \(T=200\,\mathrm{ms}\), and the sampling rate is \(f_{s}=40\,\mathrm{kHz}\).  
The computer simulation is based on BELLROP and is implemented in Matlab software. BELLROP is a beam tracing model for predicting acoustic pressure fields in ocean environments [23]. The underwater environment is set as: the water is 100 m deep, the initial horizontal range between the transmitter and receiver is 1000 m. the transmitter is fixed at the depth of 80 m, and the receiver is at 30 m depth with a horizontal speed of 4.5 m/s toward the transmitter. The speed of the acoustic wave is set to be 1500 m/s. In addition, the reflection coefficients of the bottom and the surface are set to be 0.7 and \(-0.9\), respectively. As shown in Figure 1.  
algorithm shows performance degradation at low sampling rate.
## 4 Discussion
In concrete:  
* The collector field performance is defined by: orientation (south), tilt angle (15\({}^{\circ}\) less than the site latitude), collectors area A\({}_{\rm col}\) the optical factor FR\({}_{\tau\alpha}\) and the thermal losses FRU\({}_{\rm L}\) (0.825 and 1.1 W/m\({}^{2}\)K, respectively). * The absorption machine efficiency is determined using the Felix Ziegler characteristic equation [19]. It has three parameters: thermal size s (kW/K) (i.e., machine size), the heat exchange capacityallocation \(\alpha\) and the internal losses \(\Delta\)T\({}_{\min}\). As discussed in [18], a good design will approach \(\alpha\) = 0.5 and \(\Delta\)T\({}_{\min}\)\(\approx\) 0. As practical values we assumed: \(\Delta\)T\({}_{\min}\) = 3.5 K and \(\alpha\) = 0.2, \(\alpha\) = 0.5 for a bad and good design respectively. Regarding the operational parameters the method fixes chilled water temperature T\({}_{\rm e}\) (5 \({}^{\circ}\)C or 14 \({}^{\circ}\)C). The generator temperature T\({}_{\rm g}\) is variable as the result of an energy balance between the machine and the solar field. The machine is allowed to produce cooling only if T\({}_{\rm g}\)\(>\) 75 \({}^{\circ}\)C. The absorber temperature T\({}_{\rm a}\) equals the wet-bulb temperature and the condenser one is T\({}_{\rm c}\) = T\({}_{\rm a}\) + 2.5 (\({}^{\circ}\)C). Finally, the \(\Psi\) = A\({}_{\rm col}\)/s parameter represents how big is the collector field with respect to the machine size. In our case, for a 35 kW cooling capacity machine its \"size\" would be s \(\approx\) 1.2 kW/K, thus for A\({}_{\rm col}\) = 122.5 m\({}^{2}\), \(\Psi\) = 100 m\({}^{2}\)K/kW. The relative size of the driving solar power to the cooling machine is very important and determines the overall cooling driving potential DDGH (K-h) (alike to the degree days concept). The annual cooling effect is computed as:  
\[\rm Q_{e}\ (kWh)=s\text{-DDGH} \tag{2}\]  
This value is tabulated for each site and for all the aforementioned parameters fixed. For instance, for Madrid producing chilled water at 5 \({}^{\circ}\)C and with a good machine \(\alpha\) = 0.5 table 13 in [18] gives DDGH = 23022 K-h. Therefore the estimated upper bound is Q\({}_{\rm e}\) = 27,626 kWh while our results provide Q\({}_{\rm e}\) = 22,718 kWh. A machine designed badly, in the same conditions, would yield Q\({}_{\rm e}\) = 14,072 kWh. Moreover, the overall performance computed as the ratio between the cooling energy effect and solar radiation impinging onto the collector field in our case is 0.25. Roughly, for Spanish climates, this ratio has a peak value of 0.33 achieved at around \(\Psi\) = 200 m\({}^{2}\)K/kW. Our conclusion is that our design is close to be optimal.
## 5 Discussion
### Limitations  
Despite these contributions and implications, the exploratory nature of this study has several limitations. The first limitation is posed by the corpus. Our corpus was obtained from a full-text search of the database, but the search results are limited to a certain number of characters by the database specifications, not paragraphs. Retrieving the text in paragraphs might make it possible to clarify the perception more precisely. The second limitation is interpretation. As typified by text mining, natural language processing (NLP) can quantitatively analyze a large amount of text. However, bias can be introduced when interpreting the results obtained. This is confirmation bias or apophenia (the perceptual action of finding regularity and relevance in random or meaningless information). Although we have carefully identified them, these biases are still an unsolved problem associated with NLP [54]. The third limitation in the study is related to conducting a single case study of AI adoption by the Japanese business sector. Therefore, the validity of the five-stage model must be improved. In particular, the contribution to innovation theory must be limited because the amount of text was reduced when the data were classified by the adopter category. In this regard, it is important to include different cases.
###### Abstract  
This study, conducted in the geological context of the Yixin coalfield, systematically performed indoor mechanical tests to analyze the impact of different stress conditions on the permeability of weakly cemented sandstone. The results were used to establish numerical simulations of permeability curves, revealing the following key findings. (1) After saturation, weakly cemented sandstone transitions from brittle to plastic failure. Numerical simulations closely matched experimental results, ensuring the accuracy of subsequent permeability simulations using the Hoek-Brown method. (2) Indoor permeability experiments identified a unique \"\(\surd\)\" shaped permeability curve for weakly cemented sandstone, differing from traditional sandstone. Numerical simulations confirmed this pattern and provided a basis for modeling weakly cemented strata under varying confining pressures. (3) The mesoscopic analysis of numerical simulation shows that that confining pressure limits the expansion of microcracks, while pore pressure causes cracks to develop from high- to low-pressure areas. Increasing pore pressure gradually raises permeability, and elevated confining pressure initially reduces, then increases permeability. (4) A damage parameter \"D\" was introduced to monitor fractures during compression simulations, showing that with increasing confining pressure, the damage parameter decreases and then sharply increases. Hydraulic pressure differentials directly correlated with the damage. This comprehensive study enhances our understanding of weakly cemented sandstone's hydrological behavior under varying stress conditions and parameters.  
w ackymed sandstone; permeability; stress conditions; triaxial compression; damage analysis Article
## 2 Antenna Modelling
### Antenna's Performance and Enhancing Wireless Communication Devices' Functionality  
When it comes to improving the functionality of wireless communication devices in real life, the performance qualities of an antenna are of the utmost importance. These  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Name** & **Description** & **Value** \\ \hline Le & Monopole Element Length & 15.76 mm \\ we & Monopole element Width & 15.76 mm \\ \(\alpha\) & Taper angle at monopole base & 35.64 \\ Sf & Feed gap & 64.53 um \\ Wg & Ground Width & 31.52 mm \\ Lg & Ground Length & 25.21 mm \\ H & Substrate Height & 975.6 um \\ \hline \hline \end{tabular}
\end{table}
Table 1: Dimensional characteristics.  
Figure 1: Antenna Model, (**a**) Dimensional View, (**b**) Side View, (**c**) Prototype Model.  
Figure 2: Structure and analysis, (**a**). cross sectional view, (**b**). smith chart.  
features have a direct effect on how well the gadget can send and receive signals. Here is more about how important they are: Pattern of Radiation: The pattern of radiation shows how an antenna sends or receives electromagnetic waves in different directions. A well-made antenna with a controlled radiation pattern makes sure that messages go where they are needed, giving the best coverage and the least amount of interference. In real life, this means better signal strength, fewer dead spots, and better use of the radio spectrum. Gain is a measure of how well an antenna directs energy in a certain way. Higher gain antennas can increase the range of communication, which makes them useful in places where coverage over a long distance is important, like in rural or remote areas. Bandwidth: The range of bands that an antenna can work well at is determined by its bandwidth. With a wide bandwidth, the antenna can handle a wider range of messages, making it useful in situations where different applications or services use different frequency bands. Polarisation: Aligning the polarisation of an antenna is essential for receiving and sending signals. Making sure that the antenna's polarisation matches that of the signal source or target improves signal strength and reduces signal loss due to polarisation mismatch.
# Real-Time Tomography of Gas-Jets with a Wollaston Interferometer
## 3 Data Analysis for Interferometry and Real-Time Tomography  
The Wollaston interferometry setup introduced in the previous section can be used to measure phase projections along the propagation direction of the interferometry laser. An optically-transmitting object that has a refractive index close to one (e.g., a gas jet) can be characterized. If the studied object can be assumed to be rotationally symmetric around a central axis, an Abel inversion yields the 3D density distribution from a single phase projection, i.e., a 2D projection obtained in one single observation direction, which is perpendicular to the axis of symmetry. In order to obtain the 3D density distribution of an object without such symmetry (e.g., a gas jet with a shock front), several projections along different angles are needed. The 3D distribution can then be reconstructed with tomographic algorithms, for instance the Maximum Likelihood Expectation Maximization (ML-EM), cf. Section 3.2.1. The images showing the interference fringes obtained with the Wollaston interferometer (Section 2.3.1) need to be evaluated numerically in order to obtain quantitative information about the phase projections and hence to be able to reconstruct the asymmetric, spatial density distribution.
## 4 Results
### Visualization Techniques and Data Presentation
#### 4.5.3 Uncertainty Assessment of the Comprehensive Index  
To evaluate the robustness of the comprehensive index, an uncertainty assessment was conducted by varying the weights of the components in the index formula. This assessment aimed to determine the sensitivity of the index to changes in weight values and to examine the impact of these variations on the prioritization of air quality monitor locations, as shown in Figure 11.  
Figure 10: Top 20 Proposed Locations for Air Quality Monitors in Gangeo-gu.  
The analysis revealed that the comprehensive index results remained relatively stable across the different weight configurations, indicating consistency in the identification of priority areas. Specifically, we found the following:  
* Increasing the weight of W1 (Density of Vulnerable Populations) led to proportional increases in the comprehensive index values for Yeomchang-dong, Gayang 2-dong, Hwagok 8-dong, and Deungchon 2-dong, highlighting the impact of population density in these areas.
* Adjusting the weight of W2 (Accessibility to PM-Related Facilities) resulted in increased index values for Deungchon 3-dong, Yeomchang-dong, Hwagok 3-dong, and Hwagok 6-dong, emphasizing the importance of accessibility in these regions.
* When the weight of W3 (Environmental Indicator--PM Concentration) was increased, there was a corresponding rise in the index values for Gonghang-dong, Banghwa 1-dong, Hwagok 2-dong, and Deungchon 3-dong, reflecting the influence of environmental conditions in these areas.  
This uncertainty assessment demonstrates that while minor variations in index values were observed with changes in the weights, the prioritization of areas for air quality monitoring remained largely consistent. The stability of the comprehensive index under different weighting scenarios supports the robustness of this approach in identifying optimal locations for air quality monitors in Gangseo-gu.
# The Use of Underwater Gliders as Acoustic Sensing Platforms  
[PERSON]  
1 College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310012, China; [EMAIL_ADDRESS] (C.J.); [EMAIL_ADDRESS] (W.X.)1 College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310012, China; [EMAIL_ADDRESS] (C.J.); [EMAIL_ADDRESS] (W.  
the marine soundscape by using acoustic recordings from southern elephant seals. The results showed that the system performed good measurements of the Indian Ocean soundscape.  
Some researchers use gliders carrying multiple hydrophones. In addition to target detection, those gliders can estimate the target azimuth to a certain degree. In [10], an underwater glider mounted with two hydrophones was deployed for studying marine mammal population density. The glider's recording system could detect and classify the sounds from different mammals, and sometimes even track and locate them. In [11], a two-hydrophone payload was developed and equipped in a deep-water glider. The payload could sense the underwater acoustic environment, and detect and classify marine mammals. Furthermore, in [12], a glider equipped with a small volumetric acoustic array was used to monitor marine traffic. The experimental results proved the ability of the system to track a nearby surface vessel.  
Most studies analyzed the collected data to show the detection capability, but the detection performance was only sparsely and fragmentarily addressed. In this paper, the underwater target detection ability of the acoustic glider is studied at different distances, and the target azimuth estimation ability is discussed in a range up to 6 km by a sea test. A passive recording system is developed and different set-ups of hydrophones are presented. The broadband signal is transmitted in the sea trials and the superiority of the glider to autonomous underwater vehicles (AUVs) in detecting underwater targets is illustrated by a simulation using the estimated transmission loss of the experimental data. To further improve the signal receiving ability, adaptive line enhancement (ALE) is utilized to reduce the influence of self-noise [14; 15; 16]. Meanwhile, the azimuth estimation ability of the glider is analyzed, and a simple scheme to resolve the port-starboard ambiguity is proposed. To obtain effective measurements of underwater acoustics, the self-noise of the glider and the ambient noise are also studied. The characteristics of the self-noise are displayed, and the spatial distribution of the collected ambient noise is shown.  
The paper is organized as follows. In Section 2, the glider, acoustic acquisition system, and two sea trials are introduced. Section 3 presents the self-noise of the glider. Section 4 illustrates the application of gliders in underwater ambient noise collection and passive surveillance. Section 5 concludes the work.
# Radial and Oblique Impact Testing of Alpine Helnets onto Snow Surfaces
###### Abstract  
Recent studies have found that alpine helmets reduce the risk of focal injuries associated with radial impacts, which is likely due to current alpine helmet standards requiring helmets to be drop-tested on flat anvils with only linear acceleration pass criteria. There is a need to evaluate the performance of alpine helmets in more realistic impacts. The current study developed a method to assess the performance of alpine helmets for radial and oblique impacts on snow surfaces in a laboratory setting. Snow samples were collected from a groomed area of a ski slope. Radial impacts were performed as drop tests onto a stationary snow sample. Oblique impacts were performed as drop tests onto a snow sample moving horizontally. For radial impacts, snow sample collection time was found to significantly (\(p=0.005\)) influence mean peak linear headform acceleration with an increase in ambient temperature softening the snow samples. For oblique tests, the recreational alpine sports helmet with a rotation-damping system (RDS) significantly (\(p=0.002\)) reduced mean peak angular acceleration compared to the same helmets with no RDS by approximately 44%. The ski racing helmet also significantly (\(p=0.006\)) reduced mean peak angular acceleration compared to the recreational alpine sports helmet with no RDS by approximately 33%, which was attributed to the smooth outer shell of the ski racing helmet. The current study helps to bridge the knowledge gap between real helmet impacts on alpine snow slopes and laboratory helmet impacts on rigid surfaces.  
alpine sports; head injury; helmets; impact biomechanics; injury prevention; protective equipment; skiing; snowboarding +
Footnote †: journal: Applied  
Accepted: 3 March 2023