esa-sceva/satcom-chunk-collection huggingface dataset:
# Regional Geomagnetic Field Modeling Based on Associated Legendre Polynomials
## 3 Data and Modeling Results  
### Data Sources and Pre-Processing  
Geomagnetic anomalies are residual magnetic fields derived by removing the main, varying, and induced magnetic fields from the global magnetic field, also known as the crustal or lithospheric magnetic field. EMAG is compiled based on satellite magnetometry, ocean magnetometry, and aeromagnetic measurements, and the latest EMAG2v3 database was released by the U.S. National Centers for Environmental Information (NCEI) in 2016 [22] and updated in 2017. This database includes converted 4 km altitude and sea level data, formatted as a grid with abundant available data points as well as high fidelity and accuracy, with the minimum resolution reaching 2' (approximately 3.7 km) globally. These data can be applied for aeromagnetic surveys, ocean exploration, geomagnetic navigation, and other related applied research [23; 24] (EMAG2v3 data were obtained from [[https://www.ncei.noaa.gov/products/earth-magnetic-model-anomaly-grid-2](https://www.ncei.noaa.gov/products/earth-magnetic-model-anomaly-grid-2)]([https://www.ncei.noaa.gov/products/earth-magnetic-model-anomaly-grid-2](https://www.ncei.noaa.gov/products/earth-magnetic-model-anomaly-grid-2)) (accessed on 15 December 2024)).  
To maintain the orthogonality of the associated Legendre polynomials, it is crucial to normalize the latitude and longitude coordinates of the data, ensuring that the values lie within the interval \([-1,1]\):  
\[\left\{\begin{array}{l}\Delta\varphi_{i}=\left[\varphi_{i}-\frac{1}{2}( \varphi_{\mathrm{max}}+\varphi_{\mathrm{min}})\right]/\left[\frac{1}{2}( \varphi_{\mathrm{max}}-\varphi_{\mathrm{min}})\right]\\ \Delta\lambda_{i}=\left[\lambda_{i}-\frac{1}{2}(\lambda_{\mathrm{max}}+\lambda _{\mathrm{min}})\right]/\left[\frac{1}{2}(\lambda_{\mathrm{max}}-\lambda_{ \mathrm{min}})\right]\end{array}\right. \tag{7}\]  
where \(\varphi_{i},\lambda_{i}\) represent the value of the latitude and longitude coordinates of a data point, \(\varphi_{\mathrm{max}}\),\(\varphi_{\mathrm{min}}\) denote the maximum and minimum values of the latitude coordinates, \(\lambda_{\mathrm{max}},\lambda_{\mathrm{min}}\) denote the maximum and minimum values of the latitude and longitude coordinates, and \(\Delta\varphi_{i},\Delta\lambda_{i}\) represent the results of normalizing the latitude and longitude coordinates, respectively.
# Advances in Toughening Modification Methods for Epoxy Resins: A Comprehensive Review
## 2 Rubber Toughening
### Factors Influencing Rubber Toughening  
The factors affecting the toughening effect of rubber are complex and multi-faceted. In addition to key parameters such as rubber particle size, content, and distribution, the inherent properties of the epoxy resin, the interface conditions between the matrix and the dispersed phase, and their compatibility also significantly impact the rubber toughening effect.
## 3 Factors Influencing and Mechanistic Pathways in Egg Yolk Emulsification
### Chemical Treatment
#### 3.1.3 Egg Yolk Oxidation and Emulsifying Properties  
Egg yolk oxidation during processing presents a significant challenge for food production. The degradation of lipids and proteins within egg yolk not only compromises nutritional value, flavor, and aroma but also adversely affects its emulsifying properties. Oxidative changes can alter the structure and functionality of egg yolk components, leading to reduced emulsion stability and increased droplet size. For instance, [PERSON] et al. [62] investigated the effects of malondialdehydedehyde on the high-density lipoprotein emulsifying properties of egg yolks by setting up a simulated oxidation system. It was found that when the extent of oxidation increased, both emulsifying activity and emulsion stability gradually decreased. As malondialdehydedehyde levels increased, surface hydrophobicity decreased, leading to hydrophobic aggregation of egg yolk HDL. Malondialdehydedehyde and proteins reacted with Schiff bases forming oxidized aggregates. Eventually, this aggregation led to a decrease in the emulsifying capacity because it made protein molecules less flexible and compromised the stability of the emulsification interface [63].  
Among the various strategies for mitigating oxidation in foods, the use of antioxidants emerges as the most effective, practical, and cost-efficient approach. Food manufacturers worldwide incorporate antioxidants to stabilize lipids and maintain product quality [64]. [PERSON] et al. [65] demonstrated the potential of natural antioxidants, such as menthol, trans-cinnamaldehyde, vanillin, and thymol, in preserving egg yolk quality and enhancing its emulsifying properties. Vanillin exhibited the strongest antioxidant activity, followed by thymol, menthol, and trans-cinnamaldehyde. Importantly, the antioxidant activity of all compounds increased with concentration. While all four antioxidants improved egg yolk emulsifying activity, only vanillin significantly enhanced emulsion stability. Thymol and trans-cinnamaldehyde had no notable impact on emulsion stability, whereas menthol decreased it.
# Microbial Bioremediation and Biodegradation of Petroleum Products--A Mini Review
## 4 Emerging Biodegradation Technologies
### Bioremediation
#### 4.3.3 Bioreactor  
The conversion of polluted media via a series of biological processes in a vessel (bioreactor) to a specific product is an effective bioremediation technique. Engineered bioreactors designed to provide optimum conditions for microbial growth and biodegradation were designed for use in bioremediation strategies to improve the various anticipated objectives [61]. bioreactors can be in batch, continuous, fed batch, and multistage mode and are aimed at optimizing microbial processes concerning polluted media as well as the kind of pollutant. Slurry bioreactors offer an ex-situ eco-sustainable way to remediate most soils and sediments from petroleum hydrocarbons and explosives when formed into a slurry [61; 65]. The most fundamental biofilter bioreactor consists of a sizeable media bed where the microorganisms pass through the pollutants for degradation. Biofilters are among the earliest known bioremediation techniques used in the environment. The trickling filter is an example of a biofilter, which has a wide potential for treating various wastewater or liquid-formed waste [65; 69]. Microorganisms grow on the surface of the packaging material in biofilm forms and are responsible for the degradation of effluent pollutants. Membrane bioreactors use a membrane to create a biological filtration system [65]. The membrane offers a barrier that excludes the solid from the liquid component while ensuring good effluent quality. The fouling of the membrane has been identified as an important drawback in its utilization for the bioremediation process, as well as the cost of the membrane, which makes the process expensive.
# The Relationship between Gait Velocity and Walking Pattern in Hemiplegic Patients
## 1 Introduction
In hemiplegic muscle weakness, spasticity and spastic synergistic activation patterns interact and also affect the trunk and pelvis trajectories; we can observe the mechanical consequences during the clinical evaluation as gait impairment [17]. As stated, hip hiking gait is a strategy used to compensate for the insufficient flexion of the hip joint during the swing phase, as well as knee flexion and ankle dorsiflexion,  
Figure 1: Compensatory gait patterns allowing paretic limb clearance during swing. From left: hip hiking, vaulting and circumduction. thus shortening the paretic limb. To achieve forward progression of the lower limb, the patient lifts the pelvis on the affected side more than in the normal walking pattern and in the meantime he bends the trunk laterally on the opposite side. That movement is made possible by the activation of paravertebral and lateral abdominal muscles, increasing the trunk inclination and pelvic rotation. It is common to observe an associated posterior trunk inclination at the beginning of the swing phase in this gait pattern, often at lower speed and with the prevalence of weakness of the hamstring muscles. In the pure hip hiking gait, there are no rotation or abduction movements of the hip joint, but the combination of this pattern and the circumduction pattern is unusual [17]. The last is vaulting. In this case the patient rises up on his toe on the unaffected side to achieve adequate foot-floor clearance of the paretic side during its swing phase to promote the leg progression. In a normal gait, the moving forward/swinging leg becomes shorter to allow this by keen flexion, hip flexion and ankle dorsiflexion. In an hemiparetic/hemiplegic patient, due to spasticity and involuntary activation synergy, knee bending could not occur and he could present a foot drop or an equinus foot (overactivation of triceps surae), so the progression of the paretic limb is made possible by lengthening the contralateral. Overall, the vaulting pattern is the most inefficient and expensive in terms of energy cost [17]. Depending on the group of muscles involved and the intensity of spasticity and flacedity, as already stated, post-stroke patients could perform combined walking strategies but without specific patterns, unclassifiable and indescribable in terms of the known ones. The aim of this study was to assess, in a sample of hemiparetic patients, whether these compensatory patterns influence walking speed. The relationship between gait speed and impairment and disability scores, selective muscle strength and range of motion of the lower limb joints were also considered, in order to bring possible rehabilitation implications to light.
# Estimation of Compressible Channel Impulse Response for OFDM Modulated Transmissions
## 1 Introduction
All the methods indicated in the table belong to the DFT-based solutions with the initial Least Squares channel frequency response estimation but differ in the principle of the final CIR coefficients selection (single or in groups) and in the design of the error metrics (noise energy or residual error energy) used for the control of the selection procedure. \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Single/In groups** & **Noise/Residual** \\
**CIR Estimation Method** & **CIR Coefficients** & **Energy Based** \\  & **Reconstruction Approach** & **Error Metric** \\ \hline Classical DFT-based [9] & \(-/+\) & \(-/-\) \\ Modified DFT-based [14; 15] & \(+/-\) & \(+/-\) \\ Classical CS [12] & \(+/-\) & \(-/+\) \\ Block CS [13] & \(-/+\) & \(-/+\) \\ Proposed & \(-/+\) & \(+/-\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Two main distinctive features of the compared methods (+ present/ \(-\) absent). Figure 1: Comparison between (**a**) sparse and (**b**) compressible channel impulse responses. The remaining parts of the paper are organized as follows: The next section outlines an OFDM transmission model and data reception rules applied during the studies. Section 3 presents general principles of DFT-based methods and briefly describes their popular implementations that are based on appropriate selection of the LS impulse response coefficients. The mathematical explanation of the proposed modification is elaborated in the last part of this section. The simulation-based performance and comparison analyses are discussed in Section 4. Section 5 provides computational complexity considerations. The last section contains final remarks on the obtained results and possible development steps for future research. Notation: Matrices/vectors are denoted by bold fonts (e.g., **C** or **c**). Their elements are indexed by italic lowercase letters in parentheses (e.g., **c**(_n_) ). Superscript in parentheses denotes the current iteration number. The symbols \((\cdot)^{H}\), \(||\cdot||_{2}^{2}\), and \((\hat{\cdot})\) denote the conjugate transpose, the square of L2-norm, and an estimated value, respectively. Italic uppercase and lowercase letters represent signal variables in the frequency and time domain, respectively. Their particular frequency or time moments are described in parentheses (e.g., \(H(n)\), \(h(n)\)). In addition, this type of font can describe system parameters (e.g., \(L\), \(N\), \(M\), etc.). To avoid ambiguity, explanations in the text clearly indicate the meaning of the variables (whether this is a signal or a system parameter).
# Hard Fusion Based Spectrum Sensing over Mobile Fading Channels in Cognitive Vehicular Networks
## 2 System Model and Problem Formulation
### Network Model  
We consider a vehicular network in multi-lane highway scenarios in which licensed and cognitive users coexisting peacefully within the same geospatial region, like the one depicted in Figure 1. We consider a large-scale fixed licensed user case where the PU accesses channel with probability \(p\). The cognitive network is an infrastructure-aided network, in which each cell is composed of a cognitive base station (or fusion center) and a number of associated SVUs. The FC coordinates SVUs collaborative sensing and their access to a vacant PU channel. Each SVU periodically performs sensing and reports its sensing information via the dedicated reporting channel to the nearby FC. According to the received local sensing results, the FC comes up with a global decision for the current cell. At this moment, some vehicles engaged in cooperative sensing may have left this cell. Hence, the FC diffuses the global decision to the next passing SVUs. We assume that the SVUs are Poisson distributed and follow the freeway mobility model. The vehicles move independently from any other, and thus, the sensing channels between PU and SVUs are all independent of one another.
## 4 Results and Discussion
### Target Appraisal  
Based on the prospectivity modeling results, we determined four gold exploration targets in the Xaidian gold deposit (Figure 12b), which may contribute to effective decision-making in next mineral exploration endeavors. Targets 1 and 2, located in the depth of No. 7 orebody with elevations ranging from \(-1300\) to \(-1700\) m, are generally continuously along the known orebody. This is consistent with the common spatially continuous fluid flow pathways. Target 3 is cited in the deep regions of JJY and DBZZ, displaying the highest mineralization probability and the largest potential areas in all targets. It has an  
Figure 12: 3D gold prospectivity modeling results (**a,c,d**) and gold targets (**b**) in the Xaidian deposit. (**a**) all variables; (**c**) only geometry variables; (**d**) only simulation variables. The target numbers are shown in (**b**). The dashed black circles and green arrow indicate the wrong prediction of reserved known areas and the black arrow points right prediction.  
elevation of \(-2000\) to \(-2500\) m. The target contains some known mineralization determined by drill holes and is located to NE and SE stretching farther along the J\(\mid\)Y\(\mid\) and DBZZ orebodies. It mostly likely represents the branch of the known orebody. Target 4 with elevations of \(-2200\) to \(-2500\) m also has a very high mineralization potential. It is uncontinous with known mineralization or other prediction areas and likely presents a new, concealed gold enrichment zone, which existence possibility has been proven in other gold belts [56; 103; 104]. The details of target location are listed in the Table S1.
## 3 Results and Discussion  
### Application Setup  
The solution introduced in the previous section has been validated with the data collected in two adjacent greenhouse tunnels located near Verona (45\({}^{\circ}\)20\({}^{\prime}\)25.9\({}^{\prime\prime}\) N 11\({}^{\circ}\)05\({}^{\prime}\)12.3\({}^{\prime\prime}\) E and 45\({}^{\circ}\)20\({}^{\prime}\)47.13\({}^{\prime\prime}\) N 11\({}^{\circ}\)146.4\({}^{\prime\prime}\) E, respectively) in Northeastern Italy from late August 2021 to early July 2022. This region experiences warm and humid conditions during the summer months, while winters are relatively mild to moderately cold.  
Each tunnel is 275.6 m\({}^{2}\) (50 m \(\times\) 5.3 m) northeast-southwest oriented and covered with transparent plastic film. It represents the module of a multispan greenhouse structure typical of this geographical area (Figure 6). As complementary information, before crop transplanting, the soil was tilted and subsequently mulched with a semitransparent green polyethylene film. For the duration of the experiment, both farms changed cultivated cropsaccording to the season: the first farm cycled through eggplants, then lettuce, and finally cucumbers; the second one cycled through tomatoes, lettuce, and finally, eggplants.
# Impact of Patient Size and Positioning on Radiation Dose in Multiphase Liver CT Examinations
## 4 Discussion
Their use of a standardized positioning aid may have captured subtle yet clinically relevant dose variations that traditional methods overlook [20]. Collectively, these studies underscore the importance of tailoring imaging parameters to patient characteristics and highlight the potential of positioning technologies to improve radiation safety and diagnostic quality. Personalization of CT protocols based on patient body composition is needed. The observed increase in DLP values with rising BMI and body width confirms the validity of using differentiated exposure settings tailored to individual patient dimensions. In this context, broader implementation of automatic tube current modulation and the adoption of protocols based on indicators such as SSDE are recommended [19]. Although our study did not demonstrate a significant impact of isocenter positioning on radiation dose, these results may suggest that the precision of patient positioning plays a lesser role in examinations involving larger anatomical areas, such as the abdomen and pelvis. Conversely, other studies, such as that by [PERSON] et al., have shown a significant influence of precise positioning in smaller scanning regions [17]. These discrepancies highlight the need for further research on the effect of isocentric positioning across different imaging protocols. Additionally, the findings may support the development of CT scanner software (Horos 4.0.0 RC5) towards automated exposure parameter adjustment and precise positioning using AI-assisted systems. Incorporating these conclusions into clinical practice could enhance patient safety by reducing unnecessary radiation exposure without compromising diagnostic image quality. At the same time, it would enable more efficient use of available technological resources and contribute to the standardization of high-quality radiological care. It is important to note the limitations of the study, such as its retrospective nature and its focus on a specific medical facility. Additionally, the lack of statistically significant differences in some analyses may be due to sample size or other unaccounted variables. Future studies could focus on a broader patient population and consider additional factors that may influence variable radiation dose.
# A Software Defined Radio Evaluation Platform for WBAN Systems
## 2 Preliminary and Related Work  
The IEEE 802.15.6 standard specifies three types of communications: NB, UWB, and HBC. Each communication type defines various configurations for the network. However, the processing flow is similar for different communications in WBAN. As specified in the IEEE 802.15.6 wireless body area network standard [11], the transmission flow of WBAN is mainly separated into four parts, which are the Medium Access Control (MAC) layer, security scheme, and Physical (PHY) layer, as shown in Figure 3. Initially, the MAC layer specifies the MAC frame format and the communication modes in the network [12], which requires a Microcontroller Unit (MCU) to process. Afterward, the security scheme needs to determine whether the link needs to be authenticated and encrypted, based on the security level of communication. The PHY layer involves the baseband processing module, where it processes the original binary data from the security scheme into a format that is suitable for processing in the RF front-end, where it is transmitted. Precisely, the responsibility of the baseband processing module is the activation and deactivation of the radio transceiver, clear communication assessment, and data reception and transmission [12]. Last but not least, the RF front-end converts the digital data into an analog signal modulated at the right frequency, passes the modulated signal to an amplifier, and transmits it by the antenna (vice versa for the receiver).  
Figure 3: Transmission flow of a WBAN that has been specified in the IEEE 802.15.6 standard.  
Figure 2: Architecture of a typical WBAN.
# Electrochemical Characteristics of Amorphous Ni-P Electroplated Thin Film
## 3 Results and Discussion
### Effect of Surface Morphology
Using these values of diameter and density, and further assuming that the spherical electrodeposits existed in a hemispherical shape on the surface (inset in Figure 7a), the surface area was roughly calculated to be approximately 1.7 times the area of the flat electrode. A compositional analysis showed that the thin film (P28_S) with the spherical electrodeposits had almost the same composition ratio as the flat thin film (P28) (Figure 7c), and the overall crystal structure was also amorphous except for the presence of Ni\({}_{3}\)P phase (Figure 7d). Figure 7: (**a**) Surface and inclined images of a Ni-P thin film partially covered with spherical electrodeposits (sample P28_S) and (**b**) their magnified images. (**c**,**d**) represent the EDS and XRD analyses of P28_S, respectively. Figure 8 shows the results of evaluating the P28_S electrode as a negative electrode for a secondary lithium battery. Notably, the initial reversible discharge capacity reached as high as 445 mAh g\({}^{-1}\) (Figure 8a). It is not yet apparent why the value slightly exceeded the theoretical capacity. It is likely that some of the oxides or surface products other than Ni-P also contributed to the capacity. It is not probable that there were any effects of the Cu substrate on the charge and discharge curves of the spherical-based Ni-P electrode, primarily due to the lack of exposure of the substrate. The cycling stability of the P28_S electrode (Figure 8b) was almost the same as that of the P28 electrode, except for a rather sharp decrease in the capacity during the initial charging and discharging. Compared with the P28 electrode, it had a 50 mAh g\({}^{-1}\) larger capacity over the entire cycle. After charging and discharging 20 times, the specific discharge capacity of P28_S was 341 mAh g\({}^{-1}\), which was 1.2 times larger than that of the P28 electrode. Figure 8c shows the results of the rate performance test. As the discharge rate increased, the difference in the capacity retention rate became larger. At a 0.5 C rate, the P28 and P28_S electrodes showed capacity retention values of 69% and 74%, respectively, with values of 47% and 57% at a 1 C rate. An open structure and a large surface area of the P28_S electrode and the resulting high surface reaction rate might have been responsible for the improved high-rate characteristics compared with the P28 electrode. The rate performance of the P28_S electrode was equal to or greater than that of the Ni-P electrode reported previously [28]. Figure 8: (**a**) Charge and discharge curves for the first three cycles at a rate of 0.2 C, obtained from the sample P28_S. (**b**) Variations in discharge capacity retention and coulombic efficiency with charge–discharge cycle at a rate of 0.2 C for samples P28 and P28_S. (**c**) Comparison of their rate capability.