esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Conclusions  
In summary, we have demonstrated that the heating efficiency (SAR) of the Fe\({}_{3-x}\)Co\({}_{x}\)O\({}_{4}\) (x = 0-1) nanoparticles improves with an increase in Co content up to x = 0.75, following which it decreases with a further increase of the Co content. Magnetic and hyperthermia measurements on the 7 nm series of spherical Fe\({}_{3-x}\)Co\({}_{x}\)O\({}_{4}\) nanoparticles have shown that the \(T_{\rm B}\) and SAR follow a similar trend with a maximum at x = 0.75. Our study has revealed that the SAR value for the nanoparticles not only depends on the size and saturation magnetization, which were constant for the series, but also primarily on the effective magnetic anisotropy of the particles. Our results are in corroboration with the theoretical findings on Fe\({}_{3-x}\)Co\({}_{x}\)O\({}_{4}\) (x = 0-1), which showed a maximum of magnetic anisotropy for x to be \(\sim\)0.6-0.7. The outcome of this study showed that the spherical Fe\({}_{3-x}\)Co\({}_{x}\)O\({}_{4}\) (x = 0.6-0.7) nanoparticles have the potential of a promising material for magnetic hyperthermia therapy.  
Conceptualization, R.D. and M.-H.P.; methodology, R.D.; formal analysis, R.D.; investigation, R.D., N.P.K. and S.B.A.; resources, R.D., M.-H.P. and H.S.; data curation, R.D.,  
Figure 6: (**a,b**) Specific absorption rate (SAR) of 7 nm series of Fe\({}_{3-x}\)Co\({}_{x}\)O\({}_{4}\) (x = 0–1) nanoparticles in water, measured at alternating current (AC) fields of 800, 600 and 400 Oe and 310 kHz.  
N.P.K. and S.B.A.; writing--original draft preparation, R.D. and M.-H.P.; writing--review and editing, R.D., N.P.K., S.B.A., M.-H.P. and H.S.; supervision, R.D., M.-H.P. and H.S.; funding acquisition, R.D., M.-H.P. and H.S. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED), grant number 103.02-2019.314, and Vietnam Ministry of Science and Technology through the national-level project, grant number DTDLCN.17/19. Research at USF was funded by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, grant number DE-FG02-07 ER46438.  
Not applicable.  
The work was supported by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) under Grant number 103.02-2019.314. This research was also supported by Vietnam Ministry of Science and Technology through the national-level project DTDLCN.17/19. Research at the University of South Florida was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award No. DE-FG02-07 ER46438.  
The authors declare no conflict of interest.
# An Image Compensation-Based Range-Doppler Model for SAR High-Precision Positioning
###### Abstract  
The range-Doppler (R-D) model is extensively employed for the geometric processing of synthetic aperture radar (SAR) images. Refining the sensor motion state and imaging parameters is the most common method for achieving high-precision geometric processing using the R-D model, comprising a process that involves numerous parameters and complex computations. In order to reduce the specialization and complexity of parameter optimization in the classic R-D model, we introduced a novel approach called ICRD (image compensation-based range-Doppler) to improve the positioning accuracy of the R-D model, implementing a low-order polynomial to compensate for the original imaging errors without altering the initial positioning parameters. We also designed low-order polynomial compensation models with different parameters. The models were evaluated on various SAR images from different platforms and bands, including spaceborne TerraSAR-X and Gaofen3-C images, manned airborne SAR-X images, and unmanned aerial vehicle-mounted miniSAR-Ku images. Furthermore, image positioning experiments involving the use of different polynomial compensation models and various numbers and distributions of ground control points (GCPs) were conducted. The experimental results demonstrate that geometric processing accuracy comparable to that of the classical rigorous positioning method can be achieved, even when applying only an affine transformation model to the images. Compared to classical refinement models, however, the proposed image-compensated R-D model is much simpler and easy to implement. Thus, this study provides a convenient, robust, and widely applicable method for the geometric-positioning processing of SAR images, offering a potential approach for the joint-positioning processing of multi-source SAR images.  
range-Doppler model; synthetic aperture radar; SAR photogrammetry; image geolocation; geometric correction; accuracy improvement Article
## 3 Routing at Internal UTCs: Face-Based Greedy Routing
Since \(\Gamma\) is a straight line segment, it is obvious that \(Face(A_{i+1},\,B_{i+1},C_{i+1})\) must be closer to the destination compared with \(Face(A_{i},B_{i},C_{i})\) for \(i<k\), as illustrated in Figure 5. To prove the lemma, we only need to show that \(Face(A_{i},B_{i},C_{i})\) and \(Face(A_{i+1},B_{i+1},C_{i+1})\) are neighboring faces, and thus, a routing decision can be made by using local information only, if \(Face(A_{i},B_{i},C_{i})\) is a non-boundary face. \(\Gamma\) penetrates through a set of UTCs. According to Definitions 3 and 6, a non-boundary face is always shared by two UTCs. Thus, when \(\Gamma\) intersects with a non-boundary face, it can be considered as exiting from the current UTC or entering into the next UTC. Let us consider that \(\Gamma\) enters a UTC when it intersects with a non-boundary face, e.g., \(Face(A_{i},B_{i},C_{i})\). According to Definition 1, \(\Gamma\) does not meet any faces inside the UTC. Thus, the next face it meets, _i.e._, \(Face(A_{i+1},B_{i+1},C_{i+1})\), must be another face of the same UTC, as along as \(Face(A_{i},B_{i},C_{i})\) is not a boundary face. Since any two faces of a tetrahedron share an edge, \(Face(A_{i},B_{i},C_{i})\) and \(Face(A_{i+1},B_{i+1},C_{i+1})\) must be neighboring faces according to Definition 7. As a result, routing from the former to the latter can be achieved by using local information only. The lemma is thus proven. Lemma 1 shows that greedy routing via \(\Phi\) always advances data packets toward the destination at internal UTCs, which is in sharp contrast to node-based greedy routing, where the local minimum exists at internal nodes (as demonstrated in Figure 1b).
# A Study of the Thermodynamic Properties of Nd-C and Ce-C TRISO Fission Product Binary Systems
## 1 Introduction
### Review of Cerium-Carbon Predicted and Experimental Data  
Experimental data are also lacking in the cerium-carbon system. Many thermodynamic properties were calculated and approximated based on trends in the La-C and Pr-C systems, similar to neodymium carbide [28; 31]. See Figure 4 for the predicted phase diagram by [PERSON] et al. [19] in reference to the following discussion. Aside from pure cerium, no experimental data could be found in the 0 to 50 mol%C range, and the few  
Figure 3: Nd-C predicted. phase diagram by [PERSON] et al. [22], with experimental data by [PERSON] et al. [25], [PERSON] and [PERSON] [24], [PERSON] et al. [26], and [PERSON] [27].  
data points that do exist are solely for the CeC\({}_{2}\) and Ce\({}_{2}\)C\({}_{3}\) stoichiometric phases [19], [PERSON] and [PERSON] [32] described the sesquicarbide crystal as cubic in the Pu\({}_{2}\)C\({}_{3}\) structure with a melting temperature of 1505 \({}^{\circ}\)C, following the behavioral trends of other rare earths [31]. They also described the CeC\({}_{2}\) compound as having an \(\alpha\) to \(\beta\) phase transition at 1150 \({}^{\circ}\)C \(\pm\) 20 \({}^{\circ}\)C, a melting temperature of 2420 \(\pm\) 180 \({}^{\circ}\)C, and a CeC\({}_{2}\)-C eutectic phase transition at 2260 \(\pm\) 20 \({}^{\circ}\)C [31]. [PERSON] and [PERSON] [33] heated CeO\({}_{2}\) and graphite powder to generate CeC\({}_{2}\), and confirmed the phases present via the mass spectrometric-Knudsen cell technique and X-ray diffraction at varying temperatures. They described the low-temperature structure of CeC\({}_{2}\) as body-centered tetragonal, which transitions to pyrite cubic at 1100 \(\pm\) 10 \({}^{\circ}\)C, and a eutectic temperature of 2270 \(\pm\) 20 \({}^{\circ}\)C, both in good agreement with [PERSON] and [PERSON] [32]. The enthalpy of formation was found to be \(-\)71.1 kJ/mol [32], which is markedly different compared to [PERSON] and [PERSON]'s \(-\)25.4 \(\pm\) 1.4 kJ/mol [28; 34]. A summary of phase transition temperatures and enthalpies found in the open literature for the Ce-C system is provided in Tables 3 and 4.
# High-Frequency and Spectrum-Clean Shear-Horizontal Acoustic Wave Resonators with AlN Overlay
###### Abstract  
By bonding the sub-wavelength-thick lithium niobate (LiNbO\({}_{3}\)) layer to high-phase-velocity (\(v_{\rm p}\)) substrates, such as Si, the shear-horizontal (SH) modes no longer couple with the bulk modes leaking into substrates. As the propagation loss is no longer the major concern for these types of nonleaky SH wave devices, the _YX_-LiNbO\({}_{3}\) with a low rotation angle providing ultra-large coupling coefficient (\(k_{\rm eff}\)\({}^{2}\)) can be used. In addition, by overlaying a high-velocity layer such as AlN on top of LiNbO\({}_{3}\)/Si, the \(v_{\rm p}\) of the SH wave can be significantly enhanced at a small cost of \(k_{\rm eff}\)\({}^{2}\). By a careful design of the stack, both the wide-band spurious (Lamb wave) and near-band spurious (Rayleigh wave) are suppressed successfully. This paper focuses on the design of layered substrate not only to optimize its resonance characteristics--series frequency (\(f_{\rm s}\)), quality factor (Q), \(k_{\rm eff}\)\({}^{2}\), and temperature coefficient of frequency (_TCF_)--but also for eliminating the out-of-band spurious responses. The optimized substrate design demonstrates the minimal propagation loss, high \(f_{\rm s}\) of 3 GHz, large \(k_{\rm eff}\)\({}^{2}\) of 14.4% and a spurious-free response at 0-6 GHz. These novel nonleaky SH wave devices can potentially enable the low loss and wideband processing functions, which is promising for the 5G/6G radio frequency (RF) communication systems.  
aluminum nitride; LiNbO\({}_{3}\); 6G; shear-horizontal mode; coupling coefficient +
Footnote †: journal: _Micromachines_
## 6 AGD at the 1:5000 Scale
Following the landslide in 2021, these values reduced to 170 m/s, but by 2023, they had recovered to around 214 m/s, showing a significant recovery to conditions similar to those before the failure. In all cases, it should be noted that the values progressively increase with depth under similar conditions, from which it can be deduced that at these levels, there was no change in stiffness (see Figure 13). Figure 13: Seismic line test results for 2017, 2021, and 2023. Regarding the soil resistivity tests (Figure 14), on the date immediately after the landslides, the data from the images of the results indicate a considerable increase in the saturation of the soil profile (40 \(\Omega\)) compared to the scenarios before (294 \(\Omega\), 2017) and after the failure (140 \(\Omega\), 2021). The latter value indicates that the soil began drying via evaporation and percolation toward deeper mantles (2023). It should be noted that discontinuities were induced at depth due to a possible fracture zone associated with the influence of the large-magnitude landslides that occurred, which generated greater deterioration of the soil profile at depth, with the possibility of deeper faults occurring over time. The location of the assays, whose results are shown below, corresponds to the center of the geophysics line for the 2017 assay and the line plot for the 2021 and 2023 assays shown in Figure 11.  
In the figure above, the first column of the 2017 table indicates the number of layers determined after processing (N). The second column (p) indicates the resistivity values in Ohm-m, the third column (h) represents the thickness of each layer, and the fourth and fifth columns (d and Alt) indicate the total height measured from the surface in meters. The 2021 and 2023 figures show the 2D resistivity plots in Ohm-m. As with the previous tests, it can be observed that although the soil in 2017 presented low consistency and was susceptible to failure, there was a greater decrease in resistance immediately after the landslide in 2021. Figure 14: Resistivity test results for 2017, 2021, and 2023. Red dashed lines mean possible fracture zones. Red vertical line is borehole S1. Black dashed lines are soil stiffness zone changes. In contrast, a noticeable recovery of the resistance parameters was observed by 2023 (see Table 2). This is reflected in the hazard results shown in Figure 12.  
AGD was evidenced when analyzing the four types of tests (number of blows, direct shear tests, seismic refraction lines, and resistivity) in the different periods. A redundant relationship was observed in the tendency to identify a decrease in soil consistency and increase in saturation at the time of failure, compared to their values before the failure, as well as a recovery of such consistency and a decrease in saturation sometime after the landslides occurred.
## 3 Analysis and Comparison of Machine Learning-Based Anomaly Detection
### Deep Learning Techniques
#### 3.2.1 Long Short-Term Memory (LSTM) Model  
Long Short-term Memory (LSTM) is a type of recurrent neural network architecture that has been designed to solve the vanishing gradient problem. It can effectively capture long-range dependencies in sequential data. LSTMs are composed of memory cells and a network of gates that regulate the flow of information. Each LSTM cell maintains a hidden state, which can capture and store information over extended sequences. It also has a cell state, which selectively retains or forgets information. The gates in an LSTM, namely the forget gate, input gate, and output gate, control the flow of data through mathematical operations such as elementwise multiplication and addition [52]. Figure 2 presents the base structure of LSTM. The constituting gates enable LSTMs to learn and remember patterns in sequential data, making them particularly well suited for tasks such as natural language processing (NLP), speech recognition, and time series prediction.  
LSTMs can capture complex temporal relationships and have been instrumental in achieving state-of-the-art results in a wide range of sequence modeling tasks. The architecture (and layers) of our used LSTM model is shown in Figure 3.
## 3 Results
### Radiometric Consistency
#### 3.2.1 Assessment of the Radiometric Differences between Overlapping Blocks
& \(0.4749\) & \(0.5066\) & \(0.3567\) & \(0.4930\) & \(0.6011\) \\
3 Ig/Ir–4 Ig/Ir & Mean & \(0.0293\) & \(0.0064\) & \(-0.0003\) & \(0.0361\) & \(0.0392\) \\  & STD & \(0.0242\) & \(0.0678\) & \(0.0767\) & \(0.0616\) & \(0.0910\) \\  & RMSE & \(0.0380\) & \(0.0681\) & \(0.0767\) & \(0.0714\) & \(0.0991\) \\ \hline  & Min. & \(-0.3822\) & \(-0.2891\) & \(-0.2033\) & \(-0.4939\) & \(-0.3508\) \\  & Max. & \(0.5734\) & \(0.5924\) & \(0.4426\) & \(0.4208\) & \(0.4884\From the plots it is evident that results vary from map to map, but few general considerations can be drawn. Median values are overall around 0, while maximum and minimum values are outside of the confidence intervals and can be considered as outliers. For most cases, the variability of the differences is contained in the range [-0.2, 0.2]; thus, this interval of values is retained as significant for further analysis. The VIs can mitigate the effects of single reflectance maps, specifically the high differences registered for NIR maps are rather compensated in the NDVI maps. Moreover, with respect to the differences computed between single blocks (i.e., 3 Ig/Ir-4 Ig/Ir), results obtained considering Ig/Ir scenario (i.e., 3 Ig/Ir-Ig/Ir and 4 Ig/Ir-Ig/Ir) have narrower confidence intervals. Spatial distribution of the differences in the overlapping area is shown in Figures 9-11. For the sake of brevity, only the most significative results are presented. As a matter of fact, similar results were registered for Ig/Ir and Ig/Ir scenarios. As regarding Ig/Ir scenario, green, NIR, and NDVI maps are shown, since the other maps have a similar spatial behavior. The remaining results are reported in Supplementary Materials (Figures S1-S3). Figure 8: Box and whisker plots of differences computed on different VI maps in the overlapping area. Figure 7: Box and whisker plots of differences computed on different reflectance maps in the overlapping area. Figure 9: Spatial distribution of differences in the overlapping area. Ig/Ir scenario: green (**a**), red (**b**), red-edge (**c**), NIR (**d**), NDVI (**e**), GNDVI (**f**), NDRE (**g**), NDVIre (**h**), and NGRDI (**i**). A clear spatial pattern can be noted from the plots--the reflectance values tend to be overestimated as moving away from the center of the block (i.e., approaching the borders of the block); an analogous effect is visible in VI difference maps. This effect is more evident considering the differences calculated between the single blocks of Ig/Ir scenario (Figure 9). It is less evident when introducing also Ig/Ir scenario (Figures 10 and 11). No difference or very small differences are found in NDVI maps for all considered cases, which are uniformly distributed with no specific spatial profile in the overlapping area of blocks 3 and 4.
## 4 The N-closest Photos (NCP) Model
### Parameters of the N-Closest Photos (NCP) Model  
The performance of the NCP model is dependent on five main factors:  
* **The number of photos considered for content based similarity \(|G|\)**. Allowing the algorithm to consider a large number of photos has two main advantages: (1) the more photos the algorithm is exposed to, the greater its vocabulary, as it can only recommend tags that have been applied to this set of photos; (2) using more photos increases the likelihood of a direct match with a similar photo. On the other hand, the primary disadvantage of using more photos is the associated increase in processing and downloading time. This may be partially addressed through caching and system design.  
Figure 8: The _N-Closest Photos_ (NCP) model in use.  
* **The number of similar photos used \(|N|\)**. The size of the close photo group N must be chosen with even greater caution. On one hand, larger values of N result in more tags participating in the combination process. This in turn increases the chance of weak matches occurring with many photos that can collectively influence the tag output stage. On the other hand, larger values of N also increase the chance that a single strong match is overcome by a series of irrelevant weak matches.
* **The criterion used to determine similar photos**. Probably the most complicated aspect of implementing the algorithm is selecting a basis for extracting a subgroup of similar photos. In theory, aside from requiring the photos be ranked via a distance function, any image feature descriptors employed in visual information retrieval may be used. However, the choice of the feature influences accuracy and runtime of the approach.
* **The number of tags synthesized \(C\)**. In theory, the algorithm can generate an arbitrary number of tags for the target photo, however choosing a large value of C may not be helpful to the user and lead to lower precision.
* **The method used to combine the tags of the similar photos**. Based on the set \(N\) all tags assigned to images of \(N\) can be considered for recommendation. However, the ranking function for the tags has critical impact on the \(C\) selected tags.
# Analysis and Design of a Diplexing Power Divider for Ku-Band Satellite Applications
###### Abstract  
In dual-band RF front-end systems, to transmit different frequency signals in different paths, each path requires the power to be divided along two transmission channels. In such systems, a circuit is created in which the input ports of power dividers with different frequency bands are connected to the output ports of a diplexing circuit in a cascade form. These circuits often contain different band filters in their schemes and have a complicated design. In this paper, an innovative technique for designing a diplexing power divider for Ku-band applications is presented. The proposed structure is designed on multilayer printed circuit boards (PCBs) and the utilization of a transition based on an extended SMA connector. The extended SMA connector provides two separate paths for the transmission of the RF signals. Hence, the proposed structure eliminates the need for intricate and bulky bandpass filters, allowing seamless integration with other planar devices and components within Ku-band satellite subsystems. In fact, the proposed architecture channelizes the divided output electromagnetic signals into two separate frequency spectrums. With the presented technique, two frequency ranges are envisaged, covering Ku-band applications at 13-15.8 GHz and 16.6-18.2 GHz. With the proposed structure, an insertion loss as low as 1.5 dB was achieved. A prototype of the proposed power-divider diplexing device was fabricated and measured. It exhibits a good performance in terms of return loss, isolation, and insertion losses.  
diplexing device; bandpass filters; Ku-band systems; space probe applications; power dividers +
Footnote †: journal: Physics Letters A