esa-sceva/satcom-chunk-collection huggingface dataset:
# Secure Physical Layer Network Coding versus Secure Network Coding +
## 3 Butterfly Network  
### Conventional Protocol  
A typical method for NC is the butterfly NC [22], which efficiently transmits information in the crossing way as explained in Figure 2. The goal of this problem setting is composed of the following two requirements: One is the reliable transmission of the message \(M_{1}\) from \(V_{1}\) to \(V_{6}\), and the other is the reliable transmission of the message \(M_{2}\) from \(V_{2}\) to \(V_{5}\). When each channel transmits only one element of \(\mathbb{F}_{q}\), the bottleneck of this network is the channel \(e_{3}\) from \(V_{3}\) to \(V_{4}\). Here, no signal is transmitted between disconnected nodes. Hence, no cross talk occurs between disconnected nodes. However, cross talk occurs between \(e_{5}\) and \(e_{6}\) if the signal on \(e_{5}\) is different from that on \(e_{6}\). Hence,if they are different, the transmission on \(e_{5}\) has to be performed on a different time from the transmission on \(e_{6}\). However, when they are the same, these transmissions can be performed simultaneously. In this network model, only the node \(V_{3}\) has a freedom to choose the transmitted information because other nodes receive only one information so that they have no other choice for the transmitted information except for transmitting the received information. To resolve the bottleneck in \(e_{3}\), the node \(V_{3}\) transmits the modulo sum to the node \(V_{4}\) via channel \(e_{3}\). Then, both destination nodes can recover their respective intended messages while the information transmission over \(e_{3}\) is performed only once. That is, the destination node \(V_{5}\) decodes the message \(M_{2}\) from the received information \(M_{1}\) and \(M_{1}\oplus M_{2}\). Similarly, the other destination node \(V_{6}\) decodes the message \(M_{1}\) from the received information \(M_{2}\) and \(M_{1}\oplus M_{2}\).
# Review on Retrospective Procedures to Correct Retinal Motion Artefacts in OCT Imaging
## 3 Methods
### Motion Correction Strategies
#### Retrospective Approaches  
Retrospective approaches have the goal of finding a spatial, one-to-one correspondence between the voxels of two images/volumes [42]. Such a registration is an iterative process that follows a certain optimization criteria until it reaches the desired value for the similarity metric, which measures how similar both images are [43]. There are many different metrics for measuring similarity, and some popular choices are correlation [44] or mutual information [45]. Another important aspect of the registration is the kind of transformations that are allowed during the alignment process, so that the movement can be compensated, but the image is not deformed. Some of the most common transformations are rigid, affine and non-rigid. It also must be noted that, although the registration is commonly defined using one of the images as reference (pairwise registration), there are also approaches that register a set of images to a common space (groupwise registration) [46]. The latter has the main advantage of not biasing the results depending on the reference image. In this review, retrospective methods were classified according to the input data (single, complementary, and multimodal acquisitions) and to the plane (fast, slow, and coronal) used to drive the registration.
## 2 Data and Methods
### Trends Analysis  
Trend analysis methods are usually used to reveal the characteristics of variables over time. Among them, the Theil-Sen slope test is a type of regression analysis that has better robustness to missing data and outliers than the commonly used ordinary least square (OLS) regression [38; 39]. As a method of determining the significance of trends [40; 41], the Mann-Kendall test is often combined with the Theil-Sen slope test. It is a nonparametric statistical test that does not require the data to be restricted to a specific distribution and is less subject to outliers. We chose these two methods to conduct trend analysis and test the data.
## 3 Results and Discussion
### Molecular Docking  
Molecular docking as a simulation approach is a useful technique that links the protein and the ligand via various forms of interactions. It provides a validation tool to the experimental data obtained for the binding affinity and interaction modes of the ligand in the protein binding site. The complementary applications of molecular docking have been employed to improve the understanding of the interaction of compound **3** and BSA. The observed docking results for the compound **3**-BSA system show that compound **3** binds to site I (subdomain IIA) in the BSA structure (Figure 12), which is complimented with the results acquired from site marker displacement studies. The scoring of the best conformation of compound **3** when bound to BSA demonstrated the lowest binding energy conformer that binds to BSA with a free energy of \(-25.94\) kJ-mol\({}^{-1}\) and RMSD of 1.146. This compound **3** conformer is situated within the active site residues Glu152, Tyr156, Ser191, Arg194, Leu197, Arg198, Ser201, Ala209, Trp213, Arg217, His287, Ala290, Glu291, Val342, Ser343,  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Systems** & \(K_{\mathrm{SV}}\times 10^{5}\) (L-mol\({}^{-1}\)) & \(r^{2}\) \\ \hline BSA + compound **3** & 1.10 \(\pm\) 0.05 & 0.9876 \\ BSA + compound **3** + IBP & 1.08 \(\pm\) 0.06 & 0.9782 \\ BSA + compound **3** + WAR & 0.91 \(\pm\) 0.05 & 0.9823 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Binding constant of compound **3** with the co-solution of BSA and site markers.  
Figure 11: Stern–Volmer correlation derived from the BSA interaction with compound **3** at 298 K in the presence of WAR and IBP as the site markers.  
Leu346, Asp450, Leu454, Leu480 and Val481 (Figure 12). Further, compound **3** was shown to form three hydrogen bonds with BSA through residues ASP450, Arg194 and Arg198, as summarized in Table 5. The observed docking results are consistent with the previously mentioned experimental data, confirming the tight binding between compound **3** and BSA via hydrogen bonding and electrostatic interactions. Furthermore, this finding provides a good structural basis to explain the efficient fluorescence quenching of BSA emission in the presence of compound **3**. Binding to serum albumins controls the free, active concentration of a drug, provides a reservoir for a long duration of action, and ultimately affects drug absorption, metabolism, distribution, and excretion. Hence, the obtained docking results have further mapped the binding location and strength of compound **3** to the BSA.
# Diffuse-Field Equalisation of Binaural Ambisonic Rendering
## 6 Conclusions  
The inaccuracies of high-frequency reproduction in Ambisonics, caused by comb filtering from the summation of multiple analogous signals at the ears, have been addressed in this paper through the application of the diffuse-field equalisation technique. By implementing diffuse-field equalisation in binaural Ambisonic rendering as a low-computation additional stage to the binaural rendering process, the diffuse-field response of the binaural Ambisonic loudspeaker configuration is flattened out, which changes the frequency response of renders at individual sound source locations. This has been shown to, on average over all directions on the sphere, bring the spectral reproduction of binaural Ambisonic rendering closer to direct HRIR rendering.  
For the three tested loudspeaker configurations, corresponding to 1 st, 3 rd and 5 th-order Ambisonics, DFE produced small improvements in spectral difference over the sphere and sagittal plane localisation predictions. Listening tests on timbre corroborated this, though not all test conditions were statistically significant. Listening tests also showed that DFE produces a small improvement in timbral consistency between different orders of Ambisonics.  
This paper has shown that a low-computation equalisation pre-processing stage can produce an incremental improvement in the high-frequency reproduction of binaural Ambisonic rendering, however there still exists a significant difference between binaural Ambisonic rendering using the virtual loudspeaker approach and direct HRIR rendering. Therefore, diffuse-field equalisation alone is not enough to eradicate the timbral issues posed by Ambisonic rendering, and should be used as a basis for future research in improving Ambisonic rendering at high frequencies.  
Conceptualisation, T.M. and G.K.; Methodology, T.M.; Software, T.M.; Validation, T.M., D.T.M. and G.K.; Formal Analysis, T.M.; Investigation, T.M.; Resources, T.M.; Data Curation, T.M.; Writing--Original Draft Preparation, T.M.; Writing--Review & Editing, T.M., D.T.M. and G.K.; Visualisation, T.M.; Supervision, D.T.M. and G.K.; Project Administration, T.M.; Funding Acquisition, G.K.  
This research was funded by a Google Faculty Research Award and the Engineering and Physical Sciences Research Council (EP/M001210/1).  
The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.
# Research on Automatic Recognition Method of Artificial Ground Target Based on Improved HED
## 3 Research on Automatic Target Recognition Algorithm Based on Geometric Primitives of Line Groups
### Edge Extraction  
After bilateral filtering, the edge detection algorithm based on the improved HED network was used in the image to extract the salient appearance details of the target. Then the Canny edge detection algorithm was combined to complete the extraction of the target edge.  
It can be seen from Figure 11 that merging the edges extracted by the improved HED network and Canny could effectively reduce the background edges in the image and obtain significant target edges.
# Advanced Scanning Technology for Volume Change Measurement of Residual Soil
###### Abstract  
Weathering processes of rocks lead to the formation of residual soil layers, which are typically characterized by a deep groundwater table and a thick unsaturated zone. Hence, the calculation of a slope's safety factor under the influences of climatic circumstances is a function of unsaturated characteristics, such as the soil-water characteristic curve (SWCC). To determine the SWCC, the volume of the soil specimen must be determined in order to compute the void ratio and degree of saturation. The drying processes of the soil specimen led to uneven soil volume change during laboratory SWCC testing, demanding the development of a soil shrinkage curve. Several methods for measuring soil volume change have been developed over the years. However, there are significant limitations, and it is rarely used due to the difficulty linked to accurately measuring the soil volume during drying processes. In this study, a revised scanning approach is developed to evaluate residual soil volume change utilizing 3D scanning technology. The proposed method is applied in a case study on residual soil from the Old Alluvium in Singapore. The laboratory data and analysis results suggested that 3D scanning technology should be required to provide a correct estimation of the air-entry value of soil.  
soil-water characteristic curve; 3D scan; shrinkage curve; residual soil; unsaturated soil
## 3 Analysis of Success Probability
### Success Probability in Hybrid Cognitive Networks  
The success probability is given as the average delivery rate (or service completion rate) at any test receiver. Under the hybrid spectrum access mode, such an analysis depends on the transmissions in both the overlay and underlay modes.
# Biological Importance of Cotton By-Products Relative to Chemical Constituents of the Cotton Plant
## 4 Chemical Compounds in Cotton
### Terpenes
#### 4.1.1 Terpene Biosynthesis  
Terpenes are synthesized via the acetate/mevalonate pathway [133] and mevalonate independent pathway [127; 128]. The non-mevalonate pathway is also referred to as the deoxyxylulose phosphate (DXP) pathway or the methyl erythritol phosphate (MEP) pathway. Although terpene synthesis begins with photosynthesis, most studies identify the combination of three acetyl CoA molecules as the starting point of terpene or terpenoid biosynthesis via the acetate/mevalonate pathway [134].  
The mevalonate and non-mevalonate pathway result in the formation of isopentenyl pyrophosphate (IPP) and dimethyl allyl pyrophosphate (DMAPP) which forms isoprene catalysed by isoprene synthase. Monoterpenes are synthesized in the plastids of plant cells from geranyl pyrophosphate (GPP) (Figure 4) which is formed from the combination of DMAPP and IPP catalysed by isoprenyl diphosphate synthases [135]. Sesquierpenes (Figure 4) are synthesized in the cytosol from farnesyl pyrophosphate (FPP), which is formed from one molecule of GPP and IPP joined in a head to tail combination. The activity of sesquiterpene synthase enzymes converts FPP to sesquiterpenes via ionization reactions [136]. Other terpen, diterpenes, and triterpenes are synthesized from FPP via the formation of geranyl geranyl diphosphate (GGDP) and squalene, respectively (Figure 4). Both pathways of terpene biosynthesis can, thus, be summarised into a four step process: (1) synthesis of IPP and isomerization to DMAPP; (2) addition of more IPP compounds; (3) terpene backbone formation by terpene synthase activity; and (4) enzymatic modification to induce specific functions of the terpen [129].  
Figure 3: Chemical structure of isoprene (building block of terpen).
## 4 Discussion
### Root Distribution  
The root system is a crucial organ for plants to absorb and transport water and nutrients. The morphological distribution and growth status of the root system in the soil determine the growth of the aerial component of the plant [59; 60]. The number and length of first-order and secondary lateral roots reduced significantly (\(p<0.01\)) with increasing water retention agent dosage in this investigation. The diameter grew as the water retention agent dosage was increased, however, the rise was not statistically significant. The findings on quantity and length are inconsistent with earlier research. Previous studies on Haloxylon ammodendron [61] and potatoes [62] demonstrated that water retention agents can improve soil moisture conditions and thus enhance plant root morphological growth. However, studies on muskmelons and cucumbers have demonstrated that water retention agents do not promote root growth when soil moisture is adequate, but rather act as an inhibiting factor [63; 64] Some plant species have higher water demands (stimulating root growth), whereas others with lower water demands may experience poor root development as a result of rising water levels. Unless plants are properly acclimated to aquatic conditions, excess water asphyxiates the roots. We suppose that because _Amorpha fruticosa_ is a woody shrub with tolerance to water stress and low or moderate water requirements, SAP does not provide additional benefits. Through its water absorption characteristics, the water retention agent limits the transit of soil water to the root system to a certain extent and alters the composition of soil particles. Soil aeration becomes inadequate, reducing the vitality of the root system and consequently impairing root growth. However, SAP may promote the growth of herbaceous plants nearby, as well as root growth of species with higher water demands on slopes. In addition, slope stability is closely related to the length and number of roots. As the length of the root system increases, the slip resistance of the slope increases. The greater the number of roots, the wider the distribution and the deeper the vertical penetration into the soil layer, the higher the slope stability. The application of SAP had no effect on enhancing slope stability in this test. The water content of the root-soil composite soil grew as the amount of water retention agent was raised, the increment of extra cohesiveness and internal friction angle reduced, and the slope stability fell dramatically. Furthermore, we hypothesized that moderate doses might bring additional benefits that outweigh the negative influence on root length and density. The discussion of the upslope and downslope root distribution is presented in the following Section 4.3.
## 3 Results
### Design of the Experiment  
The Autel Robotics EVO Pro II Platform (Figure 3), which is one of the most versatile low-cost drones nowadays, was applied for this experiment.  
Figure 3: Autel Robotics EVO Pro II.  
Figure 2: Distribution of the excavated areas in the archaeological site of Julibriga.  
This platform is characterized by its reduced weight, slightly over 1 kg, a battery autonomy of 40 min, a maximum speed of 20 m/s, and a maximum range of transmission of 9 km. In addition to this, its little dimensions make it perfectly easy to handle. However, its biggest advantage is the RGB (Red, Green, Blue) sensor that is mounted on it. In this regard, it is possibly one of the devices with the best price/quality ratio. Its main features are shown in Table 4.  
Had the sensor been stablished, the next step implies the definition of the several configurations of the photogrammetric flights by setting the four parameters with their three levels, which correspond to the ranges that are conventionally applied in photogrammetry. Height of flight, forward and lateral overlap, and the inclination angle of the sensor are fixed according to the design that is shown in Table 3. The combination of factors affects the complexity of the project in a substantial way (Figure 4 and Table 5).  
It is worth mentioning that, as described in the methodological proposal, the experiment has been structured according to the nine flights that are shown in Table 3. When working in a case similar to the one that is described in this work, the archaeological site of Juliobriga, which is characterized by the presence of half-meter-high walls, the development of double-grid flights is interesting to obtain images of all the surfaces of the existing structures and, therefore, to improve the result. All the flights are designed according to this procedure, so as to reduce hidden areas in the model. In addition to this, in order to improve the orientation and scaling of the models and taking into account the use of low-cost sensor, pre-signaling with 15 GCPs is applied. These points are materialized with photogrammetric targets (Figure 5a). For the observation of these GCPs in RTK (Real Time Kinematics) mode, two Leica Global Positioning System (GPS) Leica GS-15 devices were applied.  
As mentioned, the use of quantitative parameters to assess the influence of each parameter in the suitability of the model is sought. Special attention is paid to the metric aspect, and to develop a proper contrast of the geometric fidelity of the models generated from the different configurations of flights, the lengths of a series of standard elements are measured in them. These elements are 1-m-long stadias, which are characterized by their invariability and the good definition of their length, due to the nature of the material that is used for their manufacturing. To this end, eight stadias were distributed through the area that was considered for the development of this research (Figure 5b).  
The location of the support (targets) and control elements (stadias) are shown in Figure 6.
## 2 Methods
### IRT Data Collection and Imaging Procedure  
The IRT tests were performed in both passive and active approaches (see [1]) by using a 640 \(\times\) 480 thermal camera (7.5-13 \(\upmu\)m, T660 FLIR System). Passive IRT (PIRT) was used to image frescoes' support walls and detect potential anomalies. PIRT uses infrared imaging to capture the natural temperature variations or mappings in materials and structures such as buildings [14]. Thanks to the rapidity of the passive IRT test, it was possible to collect images on the whole apse and structures close to it to evaluate the presence of possible areas with large inhomogeneities. For all the acquisitions, the visible RGB image of the area was also collected and superimposed to the thermogram to help interpret the thermal imprints; see Figure 2. During PIRT acquisitions, the thermal camera was handheld, and the target focused from a distance of around 6 m in a 4 \({}^{\circ}\)C and 55-60% RH environment.  
Figure 1: Sonic pulse velocity test: (**a**) on-site investigation, (**b**) measurement scheme performed in indirect mode. The + symbol indicates the hammer position, and the blue points represent the accelerometer position. (**c**) interactive report page to provide real-time verification of data and analysis.  
The active IRT was applied instead to some specific areas to acquire information at different depths. Two details of the frescoes' cycle were analyzed, as reported in the following section. The active IRT tests implemented exploited the pulse-compression thermography (PuCT) procedure introduced in [21] for the analysis of two Renaissance panel paintings and then further developed and applied to a variety of historical artworks and mock-ups; see, for example [22; 23]. The peculiarity of the PuCT procedure is combining a long excitation time, such as in lock-in thermography, with the information content of pulsed thermography. This is made possible by using a pseudo-noise (PN) heat source (i.e., a heat source that is switched on and off following a PN signal) and by applying the pulse-compression procedure to the sequence of thermograms collected during PN excitation. In particular, the temperature time-sequence of each pixel is correlated with the PN input signal. After the PuCT, the results of a virtual pulsed thermography experiment are retrieved, and they can be further analyzed with standard thermography tools. In this way, a high value of SNR can be obtained by using even low-power excitations. In this work, an 8-LED system with a total electrical power of 400W was used to heat portions of the frescoes. The PN signal modulating the LED system was generated starting from a Legendre sequence of 31 bits, with a bit duration of 10s [22]. The overall duration of active thermography acquisitions was 620 s, i.e., approximately 10 min, and the thermogram acquisition rate was 2 frames per second, so each thermal sequence consisted of 1040 images.