esa-sceva/satcom-chunk-collection huggingface dataset:
# Nearly Linear-Phase 2-D Recursive Digital Filters Design Using Balanced Realization Model Reduction
## 5 Illustrative Examples and Numerical Evaluation
### Two-Dimensional Fan Filter  
Fan filters constitute an important class of 2-D filters that find applications, for example, in geological and seismological data processing and beamforming [53,54]. This type of 2-D filter has the capability of directional filtering, where the signal is passed or rejected according to its direction. In this example, the proposed method is employed in the design of a 2-D fan filter having the magnitude response described in [55], with \(\omega_{1}\) and \(\omega_{2}\) as the two frequency variables where \(-\pi\leq\omega_{1},\omega_{2}\leq\pi\).  
\[\mid H(\omega_{1},\omega_{2})\mid=\left\{\begin{array}{ll}1&\mid\omega_{2} \mid\leq\mid\omega_{1}\mid\\ 0&\textit{otherwise}\end{array}\right. \tag{19}\]  
The first step is to construct a 2-D linear-phase FIR fan filter with order (49,49). Figure 3(a) shows the magnitude response of the initial 2-D FIR fan filter. Second, a reduced-order nearly linear-phase 2-D IIR fan filter of order (34,34) is obtained using the method proposed in Section 4. The magnitude response of the reduced-order 2-D IIR fan filter is illustrated in Figure 3(b). The group delays \(\tau_{1}\) and \(\tau_{2}\) of the reduced-order 2-D IIR fan filter are shown in Figure 3(c,d), respectively. Figure 3(e) shows the impulse response of the reduced-order 2-D IIR  
Figure 3: Magnitude responses and group delays of the reduced 2-D IIR bandpass filter described in Section 5.2.  
fan filter. The magnitude contour of the same reduced-order 2-D IIR fan filter is illustrated in Figure 4f. The number of multiplications and additions for the 2-D FIR initial filter of order (49,49) is \((N_{1}+1)\times(N_{2}+1)=2500\) and 2499, respectively. For implementation purposes, the obtained 2-D IIR fan filter with a reduced order of (34,34) has fewer computations: 1295 multiplications and 1294 additions. The computation time for controllability Gramian \(P^{s}\) and observability Gramian \(Q^{s}\) is 6.53 s. As can be seen, the designed 2-D IIR fan filter has a lower order compared with the 2-D FIR filter, which would lead to reducing the computational complexity in the implementation to achieve the same performance.
# Fingerprint-Based Localization Approach for WSN Using Machine Learning Models
## 4 Experiment Testbed
### Reference and Mobile Nodes  
The ZigBee communication protocol was employed in this study. In general, ZigBee is a low-data rate, low-power consumption, and low-cost wireless communication protocol. ZigBee protocol consists of 3 different type nodes: coordinator, router, and end-device. The experiment testbed consists of a ZigBee network with 5 sensor nodes (4 router and 1 coordinator nodes), as follows:  
1. Stationary nodes (reference nodes): a number of 4-sensor nodes (router nodes) were placed in the corners of the IIRC lab at the University of Tabuk, as shown earlier in Figure 6, whereas Figure 8 depicts the developed ZigBee-based sensor node, which acts as stationary sensor node, and Figure 9 presents the architecture of the stationary sensor node.
2. Mobile node: a single mobile node (coordinator) is required to be employed to collect the transmitted frames from the stationary sensor nodes along with the RSS values for each received frame. Figure 7 shows the architecture of the mobile target node, which consists of an Arduino uno board to obtain and process the received RSS values from the distributed stationary reference nodes.
###### Abstract  
(1) Background: This study aimed to evaluate the marginal and internal fit of ceramic crowns produced by various digital methods using microcomputed tomography (MCT) imaging. (2) Methods: The ceramic crown preparation was performed on typodont maxillary first premolar. The crown preparation was scanned with an intraoral scanner and a model scanner, and cone-beam computed tomography (CBCT) scans were performed with three different voxel sizes (0.075 mm, 0.1 mm, and 0.15 mm). The space between the crown and prepared teeth was measured at nine different points in both coronal and sagittal sections. Three different digital model acquisition techniques, namely, intraoral scanning, model scanning, and CBCT-based standard tessellation language (STL) reconstruction, were compared in terms of marginal and internal fit. (3) Results: Quantitative analyses revealed that model scanners exhibited the lowest marginal and internal gap values, indicating superior fit compared to intraoral scanners and CBCT-based models. The highest gap values were observed in the CBCT group with a voxel size of 0.15 mm. Overall, crowns obtained from model scanners demonstrated the highest success rates in both marginal and internal fit. (4) Conclusions: In conclusion, this study highlights the critical role of digital scanning accuracy in achieving clinically acceptable prosthetic fits and emphasizes the need for continued technological advancement.  
marginal fit; internal fit; crown restoration; model scanner; intraoral scanner; CBCT 2025
## 3 Experimental Results and Discussion
### Crack Openings and Tensile Strains of the Bars Crossing the Interface
The smaller shear slip values at which interfaces subjected to external compression attain their maximum resistance (Figure 12, Table 2) are associated with smaller crack widths and, hence, reduced mobilization of the interface reinforcing bars, both as clamps and as dowels (Figure 9). As already mentioned, the tensile strains recorded during testing also depended on the presence of compressive stress normal to the interface. The ratio of strain increase with the increase in the imposed shear slip for the specimens with normal compressive stress was quite small compared with that of the specimens without compressive stress. In the case of an acting compressive stress, \(\text{s}_{\text{N,ext}}\), the bars were not under the limit state of being subjected to pullout. It is noted, however, that the relative  
Figure 12: Slip at the maximum interface resistance, plotted against the embedment length. (**a**) Specimens without external compressive stress. (**b**) Specimens with external compressive stress. Empty symbols are used for specimens with cast-in bars, with full symbols for specimens with post-installed bars. Figure 13: Crack opening at the maximum interface resistance, plotted against the embedment length. (**a**) Specimens without external compressive stress. (**b**) Specimens with external compressive stress. Empty symbols are used for specimens with cast-in bars, with full symbols for specimens with post-installed bars. contribution of the axial strain and the dowel action (dowel deformation because of kinking) of the bars was not clear. The degradation of the interface resistance with cycling for the two groups of specimens, those without and those with external compression, is shown in Figure 14. A general observation is that, in the presence of external compression, the degradation of the interface resistance with cycling is smaller than for interfaces without \(\sigma_{\text{N,ext}}\). Furthermore, in Figure 14a, one can distinguish more clearly the influence of the normalized embedment length on the resistance degradation, while, in the presence of external compression, this effect is more limited. This reduced degradation with cycling that is observed in the interfaces under external compression may be associated with the smaller shear slip values and, as also corroborated by the crack width increase with the number of cycles in Figure 11, increased mobilization of the clamping action of the dowels, hence leading to reduced deterioration of the concrete surfaces.
# Improved Autocollimator for Roll Angle Measurement with an Enlarged Measuring Range
## 3 Experimental Results  
### Experimental Facility  
To evaluate the performance of the improved autocollimator, an experimental prototype was constructed, as shown in Figure 3. The LED (Daheng Optics, Type GCI-060401, Beijing, China) possessed a 620 \(\pm\) 10 nm wavelength and 3 W output power, respectively. The diameter of the central hole of the AS was 2 mm. The BS possessed a 0.5 split ratio. The diameter and focal distance of the OL were 50.8 mm and 300 mm, respectively. The CMOS (Daheng Imaging, Type ME2P-2621-15U3M, Beijing, China) possessed a 2.5 \(\upmu\)m pixel dimension and 5120 \(\times\) 5120 pixels, respectively. The WP was made of N-BK7 glass with a refractive index of 1.517 and a wedge angle of 1\({}^{\circ}\) such that the angle of the beam with directing vector \(A_{6}\) was less than 1.034\({}^{\circ}\) with respect to the optic axis. The mean transmissivity of the beam-splitting film deposited on the front of the WP was 62.3%, which made the light intensity of light spots 1 and 2 roughly equal and thus suppressed the adverse effect resulting from an inconsistent light intensity. The two light spots received by the CMOS were diverted to a computer for preprocessing (denoising and thresholding). Then, a gray centroid algorithm was employed to extract the light spot coordinates, which were used for calculating the roll angle.
# Prototype of Augmented Reality Technology for Orthodontic Bracket Positioning: An In Vivo Study
## 2 Materials and Methods
### Assessment of Accurate Bracket Positioning  
Ortho Analyzer was used to compare the preoperational bracket position plan and bonded bracket model through coordinate system quantification. The measurement parameters required were as follows: (1) The center of the bracket \(P(Xp,Yp)\) in preoperational planning, with the preoperational planning position of each tooth as the origin; (2) the position of the bonded bracket \(R(Xr,Yr)\); and (3) the horizontal deviation \((\Delta Xt)\) and vertical deviation \((\Delta Yt)\) between the actual adherence position and planned position. The X axis denotes the mesiodistal direction, whereas the Y axis denotes the inciogingival direction (Figure 6). The error of measuring position deviation ranged from--0.01 to 0.01 mm, with a mean (standard deviation [SD]) of 0.01 (0.001) mm.
# The Potential of Focusing Acoustic Retroreflectors for Architectural Surface Treatment
## 1 Introduction
### Retroreflectors and Focusing Retroreflectors
[60] show how velocity aberration due to the motion of the Earth and Moon can be compensated for by slightly splaying one face of a lunar ranging trihedral retroreflector. [PERSON] et al. [61] describe focus improvements of retroreflectors by lens design for wireless information and power transmission to portable devices. In room acoustics, a ceiling can have advantages for treatment, partly because substantial treatment can be installed without physically interfering with occupant activities. For focusing retroreflectors, the ceiling has an advantage in that people's heads will mostly be within a known range of heights--indicatively about 1.2 m seated to 1.5 m standing--allowing the selection of a generally advantageous focal length for local over  
Figure 2: Sketches of some passive acoustic devices that can have reasonably broad spectral and spatial retroreflective performance. The cat’s eye reflector is a semicircular or hemispherical mirror with a lens that focuses onto it; the second-order reflection of a dihedral corner reflector, and the third-order reflection of a trihedral cube corner reflector, are retroreflected; the van Atta reflector [56] uses equal-length pipes to spatially reverse the surface. The bottom row illustrates adjustments that could lead to focusing combined with retroreflection: increasing the cat’s eye lens’ refractive index gradient, curving the corner reflector, and varying the van Atta reflector’s pipe lengths. head reflectors. Hence, the scenarios examined in this paper could apply well to ceiling treatment, but in some circumstances they might also apply to walls or room dividers.
## 2 Current Status of Development of Geophysical Exploration Techniques
### Exploration Techniques Based on Elastic Wave Velocity  
The densities and elastic moduli of the parts of earth and rock embankments with potential leakage are different from those of normal areas. During wave propagation, some interfaces will reflect these waves while some refrac. The location and nature of these interfaces can be determined by the characteristics of these waves, such as the travel time and amplitude. In comparison, the propagation of vibration waves is more sensitive to the compactness of the medium, and the wave velocity and waveform vary when these waves pass through the hidden parts [33]. Based on the differences in the wave velocity and wave impedance between the hidden parts and normal areas inside an earth and rock-fill dam, the longitudinal and transverse waves and surface waves can be used for detection and analysis. The current exploration techniques based on the vibration wave method mainly include the seismic refraction method, surface wave method, elastic wave CT method, and land sonar method.
# A New One-Dimensional Compound Chaotic System and Its Application in High-Speed Image Encryption
## 4 Experimental Test and Security Analysis
### Histogram Analysis  
Image histogram describes the distribution frequency of gray values at all levels of the image. It visually shows whether the distribution number of pixel values of an image is uniform. Generally, the histogram distribution of meaningful images is uneven. However, the histogram of a good encrypted image should be flat and uniform so that attackers cannot obtain any useful information from the histogram of encrypted images. Figure 8 shows histograms of three test images and their corresponding encrypted images. It can be seen that the histograms of encrypted images are flat and evenly distributed.
# Adjustable Capacity Evaluation Method Based on Step-by-Step Power Mapping of Offshore Wind Farms
## 4 Result  
The data used in the calculation example comes from an offshore wind farm in Jiangsu, with a total of 67 wind turbines. All wind turbines are distributed on 12 collector lines, and the electric energy is first collected by the collector system, then boosted, and transmitted to the onshore part of the wind farm through high-voltage submarine cables for grid connection. The data of the wind farm was collected for 9 days, and the time interval was 15 min. The data of the first 8 days was used for training, and the data of the last day was verified.
###### Abstract
The fractional derivative controls the sidelobe and phase of the wavelet, and the reference frequency controls the width of the wavelet. The Ricker wavelet is a particular case where the fractional derivative of the generalized seismic wavelet is equal to 2. A method for estimating the time-domain generalized seismic wavelet is spectral fitting [36]. The key idea involves estimating the fractional derivative and reference frequency from the power spectrum of time-domain seismic data, which are fitted with a Gaussian function. Then, these parameters are used to construct the generalized seismic wavelet. However, the spectral fitting method assumes that the power spectra of seismic data are unimodal and change slowly. Nevertheless, in practical applications, the seismic power spectrum is usually multi-modal. It changes violently, and it is not always possible to find a suitable Gaussian function to fit the seismic power spectrum. Therefore, a separate parameter estimation (SPE) method has been proposed to estimate the optimal fractional derivative and reference frequency in the pseudo-depth domain [19]. However, the pseudo-depth-domain generalized seismic wavelet estimated by the SPE method is stationary, which is not suitable for areas with drastic changes in geological structures. Inspired by the research of the scholars mentioned above, we propose a method to extract depth-domain wavelets based on the generalized seismic wavelet model, which not only accommodates the non-stationarity of depth-domain seismic data but also considers the influence of media attenuation. Furthermore, we apply this method to the direct inversion of depth-domain AI. For convenience, this paper only considers the effect of attenuation on the waveform of the source wavelet, and the amplitude change of the source wavelet is temporarily ignored. The remainder of this article is structured as follows: First, we study the influence of media attenuation on source wavelets and derive an analytical formula for the wavelets of attenuation media in the depth domain. Then, the depth-domain synthetic record of attenuation media is obtained based on the non-stationary convolutional model. Secondly, we extend the time-domain generalized seismic wavelet to the depth domain. Then, the feasibility of using the generalized seismic wavelet to represent the depth-domain wavelet of attenuation media is studied. Next, we propose a method to extract the depth-domain generalized seismic wavelet directly from depth-domain seismic data based on the orthogonal matching pursuit (OMP) algorithm [37]. Then, we test our method with synthetic data examples for weak and strong attenuation. Finally, we apply this method to the depth-domain AI inversion of a 3D field data example. Additionally, we compare it with the pseudo-depth-domain SPE method [19] to analyze the accuracy of our method.
# Low-Temperature Plasma as an Approach for Inhibiting a Multi-Species Carigenic Biofilm
## 2 Materials and Methods
### Single- and Multi-Species Cariogenic Biofilm  
Single- and multi-species biofilms composed by _S. mutans_, _S. gordonii_, and _S. sanguini_s were formed as previously described [46], with modifications. Microorganisms were activated on anaerobe 5% sheep blood agar and incubated for 48 h. To prepare the pre-inoculum, the microorganisms were transferred separately from the agar plate to a centrifuge tube containing 10 mL of TSB (Becton Dickinson France SA, Le Pont de Claix, France) supplemented with 1% glucose. Tubes were incubated at 37 \({}^{\circ}\)C in 5% CO\({}_{2}\) for 18 h. Then, 1 mL of the pre-inoculum was transferred to another tube containing TSB supplemented with 1% sucrose and incubated for 6 h, corresponding to 10\({}^{8}\) CFU/mL of each microorganism. The suspensions were standardized in a spectrophotometer to confirm the number of microorganisms after 6 h of growth. Suspensions were diluted to 8 \(\times\) 10\({}^{6}\) CFU/mL according to [PERSON] et al. [12]. The same procedures were performed for each microorganism separately. For the multi-species biofilms, an equal part of each standardized suspension was deposited in a sterile centrifuge tube, and the suspension was homogenized using a vortex. For single- and multi-species biofilms, the microorganism's suspensions were added to the wells of 24-well plates containing sterile hydroxyapatite discs [13]. For each well, 200 \(\upmu\)L of the single- or multi-species inoculum and 800 \(\upmu\)L of TSB broth supplemented with 0.2% sucrose were added. To find the ideal concentration of sugar in which all the three strains (_S. mutans_, _S. gordonii_, and _S. sanguini_s) would be recovered after 48 h of biofilm growth, preliminary tests were conducted using concentrations of 0.2%, 0.5%, 0.75%, and 1% sucrose. The best sucrose concentration in which all microorganisms could be recovered was 0.2%. Biofilms were then formed for 48 h, and fresh culture medium was replaced after 24 h (37 \({}^{\circ}\)C, 5% CO\({}_{2}\)) [46].  
Figure 1: Low-temperature plasma (LTP) device kINPen09 TM (Leibniz Institute for Plasma Science and Technology, INP, Greifswald, Germany).
# Carbon Footprint Assessment on the Viability of Utilizing Brewer's Spent Grain to Produce Biochar
## 2 Materials and Methods
### Biochar Evaluation Methods  
The following methods, presented by [PERSON] et al. 2022 [23], were used to evaluate biochar quality: pH; liming potential; organic and inorganic carbon content; total porosity; and specific surface area.  
The mass of biochar recovered was correlated with the peak pyrolysis temperature. Specifically, higher volumes of biochar were recovered for all samples pyrolyzed at 400 \({}^{\circ}\)C (3.59 g average) than at 700 \({}^{\circ}\)C (2.76 g average).  
Biochar samples (250 mg) were weighed onto weighing paper, then transferred to 15 mL centrifuge tubes. DI water (5 mL) was added to each tube. Samples were mechanically shaken on a wrist-action shaker for 1 h at room temperature. They then stood at room temperature for 1 h. The pH meter was calibrated using pH 7 and 10 buffers. The pH of the suspension was evaluated three times for each sample, rinsing the probe with DI water and blotting dry with a Kimwipe between each measurement; the values were averaged.  
The total organic carbon (TOC) analysis was conducted by the University of California, Davis Analytical Lab in 2023. The analytical laboratory completed the AOAC Official Method 972.43, Microchemical Determination of Carbon, Hydrogen, and Nitrogen, Automated Method from the 16 th Edition of the _Official Methods of Analysis of AOAC International_. Briefly, the protocol involves acid fumigation with hydrochloric vapor to remove inorganic carbon. The process of flash combustion converts organic and inorganic substances into the combustion gases N\({}_{2}\), NO\({}_{x}\), CO\({}_{2}\), and H\({}_{2}\)O. The detection limit is approximately 0.02% carbon.  
Figure 1: BSG-to-biochar processing protocol.  
NaOH consumed by 1 M HCl without biochar. Equation (1) was used to determine the % \(CaCO_{3}\) equivalent:  
\[\%\ CaCO_{3}\ equivalent=\frac{M*(b-a)*10^{-3}*100.09}{2*W} \tag{1}\]  
where  
\(M\) = Standardized molarity of NaOH (mol L\({}^{-1}\));  
\(b\) = Volume of NaOH consumed (mL) by the blank;  
\(a\) = Volume of NaOH consumed (mL) by the biochar;  
\(10^{-3}\) = Conversion from mL to L;  
\(100.09\) = Molar mass of CaCO\({}_{3}\);  
\(W\) = Mass of biochar (g);  
2 = 1 mole of CaCO\({}_{3}\) consumes 2 moles of H\({}^{+}\).  
The method was found to produce an ideal biochar, categorized by a mass recovery of 25-30% initial weight, a neutral pH of -7.85, a Class 1 categorized limiting potential (1-10% CaCO\({}_{3}\) eq), a high TOC (-70%), and consistent porosity.
###### Abstract  
Plant and herbal essential oils (EOs) offer a wide range of pharmacological actions that include anticancer effects. Here, we evaluated the cytotoxic activity of EO from _Lippia alba_ (chemotype linaolo), _L. alba_ (chemotype dihydrocarvone, LaDEO), _Clinopodium nepeta_ (L), _Kuntze_ (CnEO), _Eucalyptus globulus_, _Origanum \(\times\) paniculatum_, _Mentha \(\times\) piperta_, _Mentha arreensis_ L., and _Rosmarinus officinalis_ L. against human lung (A549) and colon (HCT-116) cancer cells. The cells were treated with increasing EO concentrations (0-500 \(\mu\)L/L) for 24 h, and cytotoxic activity was assessed. LaDEO and CnEO were the most potent EOs evaluated (IC\({}_{50}\) range, 145-275 \(\mu\)L/L). The gas chromatography-mass spectrometry method was used to determine their composition. Considering EO limitations as therapeutic agents (poor water solubility, volatilization, and oxidation), we evaluated whether LaDEO and CnEO encapsulation into solid lipid nanoparticles (SLN/EO) enhanced their anticancer activity. Highly stable spherical SLN/LaDEO and SLN/CnEO SLN/EO were obtained, with a mean diameter of 140-150 nm, narrow size dispersion, and Z potential around \(-\)5 mV. EO encapsulation strongly increased their anticancer activity, particularly in A549 cells exposed to SLN/CnEO (IC\({}_{50}\) = 66 \(\mu\)L/L CnEO). The physicochemical characterization, biosafety, and anticancer mechanisms of SLN/CnEO were also evaluated in A549 cells. SLN/CnEO containing 97 \(\pm\) 1% CnEO was highly stable for up to 6 months. An increased in vitro CnEO release from SLN at an acidic pH (endolysosomal compartment) was observed. SLN/CnEO proved to be safe against blood components and non-toxic for normal WI-38 cells at therapeutic concentrations. SLN/CnEO substantially enhanced A549 cell death and cell migration inhibition compared with free CnEO.  
**Keywords:** essential oils; solid lipid nanoparticles; cancer cells; drug delivery; biocompatibility; anticancer mechanisms