esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Numerical Results  
Numerical results are referred to as two grid beams, taken as case studies, made of a thermoplastic polymer, having elastic modulus \(E=2180\) N/mm\({}^{2}\), Poisson coefficient \(\
u=0\) and mass density \(\rho=1040\) kg/m\({}^{3}\). The layout of the longitudinal fibers for the two case studies is shown in Figure 3, namely: in case study I (Figure 3a) a squared (or \"compact\") layout is considered, while in case study II (Figure 3b) a rectangular (or \"thin\") layout is taken. All the fibers and bracing elements have equal square cross-sections, of dimensions \(1.5\,\mathrm{mm}\times 1.5\,\mathrm{mm}\). The elasto-geometric characteristics of the cross-section are reported in Table 1 (\(A\) is the area, \(A^{*}\) the shear area, \(I\) the inertia moment, \(J\) the torsional inertia).  
The considered boundary conditions are: (i) clamped at the ground, case studies denoted with \"-a\", or (ii) simply supported and torsionally restrained at the ends, case studies denoted with \"-b\". The number of cells is taken as \(n=40\) or \(n=100\) and, in all the cases, \(h=10\) mm. The static loads consist in horizontal point forces, namely, \(F=0.5\) N (placed as in Figure 3), applied at each cross-section, except for the free end cross-section of the clamped case, where \(F=0.25\) N.  
Both static response, under lateral loads, and free dynamics characteristics, accounting for self-mass, are of interest. The analytical (exact) solutions relevant to the equivalent beam model are compared with the numerical results obtained by FE models, in which the grid beam is modeled as a 3D frame. Moreover: (i) a Timoshenko beam (exact) finite-element has been adopted to model the fibers of the grid beam; (ii) each fiber, comprised between two nodes of the frame, has not been meshed in static analyses, while in dynamics, it has been divided into three finite-elements.  
The elasto-geometric characteristics of the equivalent beam model are reported in Table 2 for each case study. Moreover, the distributed load and couples assigned to the coarse model are \(p_{y}=F/h=0.05\) N/mm and \(c_{x}=\left(F/h\right)3h=1.5\) N. In the following Figures, the green dots represent the FE solution, and the continuous blue curves are relevant to the solution of the Timoshenko beam model, respectively, while the displacement unit is mm.  
\begin{table}
\begin{tabular}{c c c c} \hline \(EA\) & \(GA^{*}\) & \(EI\) & \(GJ\) \\ \([\mathbf{N}]\) & \([\mathbf{N}]\) & \([\mathbf{N}\times\mathbf{mm}^{2}]\) & \([\mathbf{N}\times\mathbf{mm}^{2}]\) \\ \hline
4905 & 2043.75 & 919.69 & 778.06 \\ \hline \end{tabular}
\end{table}
Table 1: Elasto-geometric fibers’ properties for the case studies I and II.  
Figure 3: Grid beam \(x\)-fibers layout: (**a**) case study I; (**b**) case study II.
## 3 Strength Verification
### Boundary Condition Settings and Parameter Values  
To adapt to the continuous coring conditions, the core catcher material is made of low-carbon steel with good plasticity, while the drill bit material is tungsten carbide. The contact form and geometric interaction between the two are both set as frictional contact. During the coring operation, the core catcher model is subjected only to pressure from the core barrel, necessitating calculation of this pressure [24; 25; 26; 27].  
Based on engineering experience, the flow rate of the flushing fluid under the coring state is set to Q = 100 L/min. According to the geological industry standard DZ/T0227-2010 \"Regulations for Geological Core Drilling\" [28], the inner diameter D = 63 mm of the drill pipe for the \(\varphi\)75 diameter wireline core barrel, and the well depth L = 1000 m, the density of the flushing fluid is 1050 kg/m\({}^{3}\). Assuming the rheological curve of the flushing fluid follows the Bingham model, with a dynamic shear stress \(\tau_{0}\) = 6.27 Pa and a plastic viscosity \(\mu_{\text{p}}\) = 0.0416 Pa s, the average flow velocity inside the drill pipe is  
\[\upsilon=\frac{4\text{Q}}{\pi\text{D}^{2}} \tag{1}\]  
Substituting the values into the equation: \(\upsilon\) = 0.536 m/s.  
Generalized Reynolds number:  
\[\text{Re}_{\text{bh}}=\frac{\rho\text{D}\upsilon}{\mu_{\text{p}}\left(1+\frac {\tau_{0}\text{D}}{6\mu_{\text{p}}\upsilon}\right)} \tag{2}\]  
Substituting the values: Re\({}_{\text{bh}}\) = 215.64 < 2100. Therefore, the flow regime of the flushing fluid inside the drill pipe is laminar.  
Pressure loss:  
\[\Delta\text{p}=\frac{32\text{L}\mu_{\text{p}}\upsilon}{\text{D}^{2}}+\frac{16 \text{L}\tau_{0}}{3\text{D}} \tag{3}\]  
Substituting the values: \(\Delta\)p = 0.233 MPa.  
Taking the BW250 reciprocating mud pump which is manufactured by the Bailing Machinery Company, located in Zhengzhou City, Henan Province, China, commonly used in drilling operations as an example, with a maximum flow rate of 250 L/min and a maximum pressure of 6 MPa, if the pump pressure during coring is 4 MPa and the flow rate of the flushing fluid is 100 L/min, then the pressure P at 1000 m depth = 3.767 MPa, and the force acting on the core catcher would be  
\[\text{F}=\text{PA}=3.7\times\pi\times\left(\frac{63}{2}\right)^{2}\times 10^{-6} =11.74\text{kN} \tag{4}\]  
Converting the pressure P to 40.64 MPa, since the strength simulation is intended to observe the stress and strain conditions of the structure, taking into account pressure loss, the maximum pressure of 40 MPa was selected as the upper surface condition. Therefore, the upper surface boundary condition of the core claw was set to 40 MPa pressure, and the core claw was simulated for stress, strain, and closure. The simulation results are shown in Figure 5.
## 6 Conclusions  
The goal of QKD at present is to provide long-distance and high-speed key distribution. Increasing the repetition rate and narrowing the pulse width may make the pulses complex and the parameters, such as the frequency, polarization, and temporal shape, more distinguishable. Any small imperfections may be exploited and enhanced by Eve utilizing the channel loss. Therefore, it is necessary to pay more attenuation to the practical implementations of the TF-QKD systems.  
In this paper, we investigate and test the frequency side channels with the external modulation method. The imperfect IM will produce the signal and decoy states distinguishable in the frequency domain. Based on this, we propose a side-channel attack, named the passive frequency-shift attack, on the imperfect implementation of the SNS TF-QKD protocol that applies to the most general case of frequency side channels. Normally, when without the side channels, [PERSON] and [PERSON] could estimate the lower bound of the secret key rate correctly no matter what [PERSON] does. However, this estimation is not accurate once [PERSON]'s operations on the signal and decoy states are different, which may cause insecure bits when the upper bound of the secret key rate is lower than the estimated lower bound. The numerical results quantitatively show the effectiveness of the attack at a long distance if [PERSON] and [PERSON] neglect this distinguishability.  
Finally, we note that at present the side channel in the frequency domain can be restrained with more than one IM in the actual QKD systems [35,36]. We test with only one IM in this study just to prove the harmfulness of the side channels and emphasize the practical security of the light source specifically. Our results might provide a reference for the device selection in the practical implementation. The final goal is to build the hardened implementations of the practical QKD systems.  
Conceptualization, M.-S.J. and Y.-F.L.; methodology, Y.-F.L., M.-S.J. and Y.W.; writing--original draft preparation, Y.-F.L.; writing--review and editing, X.-X.Z., F.L., C.Z., H.-W.L., S.-B.T. and J.-Y.W.; project administration, W.-S.B.; funding acquisition, W.-S.B., Y.W., H.-W.L. and C.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Key Research and Development Program of China (Grant No. 2020 YFA0309702), the National Natural Science Foundation of China (Grant Nos. 62101597, 61605248, 61675235 and 61505261), the China Postdoctoral Science Foundation (Grant No. 2021M691536), the Natural Science Foundation of Henan (Grant Nos. 202300410534 and 202300410532) and the Anhui Initiative in Quantum Information Technologies.  
Not applicable.  
The authors declare no conflict of interest.
# Research on Damage Localization of Steel Truss-Concrete Composite Beam Based on Digital Orthoimage
## 4 Bridge Structure Morphology Extraction
### Calibration of Bridge Image Resolution  
The deformation of the structure is reflected in the image as a change in the pixel position of the deformed area. In the same shooting environment, how much deformation can cause the pixel position to change becomes a resolution issue for bridge image deformation monitoring. Theoretically, the deformation value has to be larger than the pixel size to be recognized by the bridge structure deformation monitoring method. The yellow calibration line is drawn in the truss vertical rod (Figure 31), which is a series of regular pixel matrix arrangements on the image, the physical size of these pixels in relation to the actual specimen is the monitoring resolution, and the calibration model is shown in Figure 32. The resolution calibration is calculated as \(R=L/n\) (mm/pixel). The test beam has a total of 15 vertical rods, and yellow calibration lines are drawn in the middle of each vertical rod during the test. The exact length of each calibration line is actually measured, the number of pixels of the calibration line is counted on the image, and then the monitoring resolution is obtained as shown in Table 5.  
Figure 30: Comparison before and after regression treatment of discontinuous edges of the test beam; (**a**) before; (**b**) after.  
Figure 29: Basic operation diagram of morphology; (**a**) open operation; (**b**) closed operation.  
The monitoring resolution of the bridge image is obtained by calibrating the pixel size. Using this resolution, the pixel dimensions of bridge images can be converted to  
Figure 31: Array arrangement of pixels in image.  
Figure 32: Pixel size calibration model.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \begin{tabular}{c} **Vertical Truss** \\ **Rod Number** \\ \end{tabular} & \begin{tabular}{c} **Number of** \\ **Pixels** \\ \end{tabular} & \begin{tabular}{c} **Calibration** \\ **Line Length** \\ **(mm)** \\ \end{tabular} & \
\begin{tabular}{c} **Calibrated Value** \\ **(mm/px)** \\ \end{tabular} &
\begin{tabular}{c} **Calibration** \\ **Average** \\ **(mm/px)** \\ \end{tabular} \\ \hline
1 & 1986 & 367.17 & 0.1849 & \\
2 & 1999 & 359.21 & 0.1797 & \\
3 & 1993 & 360.1 & 0.1807 & \\
4 & 1991 & 357.3 & 0.1795 & \\
5 & 1998 & 356.32 & 0.1783 & \\
6 & 1994 & 312.39 & 0.1567 & \\
7 & 1989 & 355.91 & 0.1789 & \\
8 & 2654 & 453.94 & 0.171 & 0.1771 \\
9 & 1982 & 356.83 & 0.18 & \\
10 & 1993 & 321.44 & 0.1613 & \\
11 & 1988 & 357.77 & 0.18 & \\
12 & 1987 & 356.75 & 0.1795 & \\
13 & 1994 & 361.37 & 0.1812 & \\
14 & 1989 & 363.1 & 0.1826 & \\
15 & 1983 & 359.47 & 0.1813 & \\ \hline \hline \end{tabular}
\end{table}
Table 5: Resolution calibration table.  
deformation monitoring dimensions, and then the measured deformation value of the structure can be obtained from the pixel bit difference.
# Digital 3D Technologies for Humanities Research and Education: An Overview
## 7 3D Modelling Technologies
### 3D Reconstruction  
In a digital reconstruction, models are created by a human-driven use of computer software. In contrast to digitization processes, where the development of technical workflows and tools is a focus in the academic discourse, human-driven workflows for digital reconstruction mostly rely on application of standardized software [394]. This software touches a variety of technological domains like geo information systems (GIS), computer graphics (CGI), computer-aided design (CAD), or building information management (BIM), each with their own standards. All approaches recommend specific tools and workflows and offer specific benefits, whether information on object volumes (BIM), a highly realistic appearance of surfaces (CGI), accurate size measurements (CAD), or large-scale geo-referenced information (GIS).  
A 3D reconstruction geometry can be created as static modelling. Static modelling requires the individual definition of every 3D geometric surface feature and is therefore a highly flexible but labor intense process. The main approaches for static modelling are _boundary representation (b-rep)_ and _polygonal modelling_[443]. Boundary representation modelling is the primary surface representation method in CAD and describes surfaces piecewise via connected polynomial representations [444]. In contrast, polygonal modelling, as used in CGI and for meshed dense point clouds created via 3D digitization, describes geometrical surfaces by triangles. Each triangle or polygon has clear information about its inner and outer side and a normal as a definition of orientation. Specific workflows for model creation differ greatly for each software program--b-rep modelling workflows tend to be shape-oriented (e.g., curves, geometric primitives) since polygonal modelling primarily focuses on points, edges, and faces (polygons).  
**Generative modelling:** Generative modelling creates a 3D geometry via pre-programmed rules [443]. Based on static modelling techniques, it reduces effort and simplifies the solid modelling process. Generative modelling still requires manual work, but eases the modelling process by predefining the structural elements of buildings and altering them on a parameter level (e.g., defining the properties and number of windows of a facade). Numerous projects use generative modelling primarily to create large-scale heritage structures such as 4D city models [190; 445; 446] and to enhance modelling quality, e.g., by a parametrization of 3D models from scanned data [447]. Another generative modelling approach tries to structure the manual modelling process by identifying common steps in the reconstruction work and translating them into digital ontology-based manuals [448]. The combination of generative modelling with recognized footprints from historical cadastre data is currently under investigation in various projects [449; 450]--e.g., by using machine learning to predict building heights from map data [450].
# Standalone GPS L1 C/A Receiver for Lunar Missions
## 2 The _WeakHEO_ Receiver Architecture
### GPS Tracking
#### 2.6.2 Weak Signal Tracking
Tests with software receiver implementations of conventional and EKF tracking in [37] show around a 4 dB to 7 dB improvement in sensitivity for the EKF approach. The EKF is well suited to applications such as the one considered here where the platform has predictable dynamics and the receiver's oscillator can be measured and modelled. For the _WeakHEO_ receiver we have implemented a first order EKF for carrier phase tracking as detailed in [29]. The EKF is only used for the carrier tracking and conventional tracking is used for the code loop to minimise the computational load. In [26] we show how Doppler and Doppler rate aiding from an integrated orbital filter can be used to improve sensitivity of conventional FLL tracking to around 11 dB-Hz. This is considered suitable for a stand-alone receiver as the orbital filter can be integrated into the receiver's navigation software. Figure 14 shows double difference measurements of the _WeakHEO_ DLL jitter taking with our GNSS simulator with varying carrier to noise density ratios. Reasonable agreement with the theoretical values can be found. Figure 13: (a) PLL jitter; (b) DLL jitter _versus_ C/No.
## 5 Results and Discussion
### Comparison of Sample Sizes Based on Determination Methods and Criteria  
To consider various conditions, the sample size in this study was determined using two methodologies: CV, which can be used only when the measured value information for the measured object is known, and Neyman allocation, which can be used when there is enough information to divide the strata. In the CV method, details related to data processing must be considered when there is no prior information, so we considered the data processing case as well. The target gases are CF4 and CHF3, which are F-gases used in the semiconductor and display industry.  
Table 18 shows a comparison of sample sizes by method of determination. It was found that to develop the DRE of CF4 gas, the CV method, which uses existing data as they are without handling outliers, required a sample size of 337. Case 3 required 85 samples, while the Neyman allocation method required 21 samples and 17 samples for Case 2. For CHF3, we found that Case 1 required the highest sample size of forty-five, followed by Case 3 in the CV method and the Neyman allocation method, which both required six samples, while Case 2 required the lowest with three samples, similar to CF4. These findings indicate that outlier removal considerably reduces the variance between measurements, suggesting that a smaller sample is needed overall. However, caution should be exercised when removing outliers, as valid data should not be removed inadvertently. For Case 3, CHF3 is similar to the sample size by Neyman allocation, and for CF4, the sample size determined by Neyman allocation is less than Case 3 but larger than Case 2. Therefore, adjusting outliers to extreme values might be a better approach than their complete removal when processing data.
## 6 Conclusions  
Transient one-dimensional consolidation of soil was modelled by using the Burgers rheological scheme and numerical integration of differential equations. Comparison with laboratory test data shows that the model provides good prediction of the soil's behaviour and an iterative curve fitting procedure can be implemented for finding the model's parameters based on laboratory tests. Constitutive equations of the soil skeleton, formulated here for the one-dimensional transient consolidation case, can be also applied for the isotropic consolidation conditions.  
Additionally, a new way of formulating constitutive equations for the soil skeleton and predicting the relationship between the effective stress and strain in drained conditions (\(e-\log\sigma^{\prime}\) curve) was presented. The set of equations for the non-classical Kepes rheological element connected in series with a spring was presented. The model was then extended by a simple addition of a rate-dependent dashpot element which allowed to take into account secondary consolidation effects. Testing the model for two different strain rates showed the well-known phenomena of the normal consolidation line shift. The presented solution can be treated as an extension or alternative to the Isotache model being developed by many researchers [29,31].  
The main findings of this paper can be summarized in the following points:  
* A method of modelling the transient process of primary and secondary consolidation of soil based on rheological schemes was presented. In the paper Burgers structure was used as an example; however, the presented procedure can be applied for any viscoelastic rheological structures. The 1D constitutive equations derived using rheological schemes can be implemented as part of the evolution law of the Cap yield surface in commercial finite element method codes.
* A new way of formulating constitutive equations for the soil skeleton in steady-state (drained) conditions using the non-classical Kepes element was presented.
* An explicit form of differential equations was formulated for the non-classical Kepes rheological element.
* Presented rheological models are able to describe the material response for cyclic loading conditions: Both for loading and unloading.  
* Formulated equations can be solved using known algorithms for solving ordinary differential equations (e.g., the Runge-Kutta method).  
Conceptualization, K.J., A.Z., M.M., K.B.; methodology, K.J. and A.Z.; software, K.J.; validation, A.Z., KB.,M.M.; formal analysis, A.Z.; resources, K.J., M.M.; data curation, K.J.; writing-original draft preparation, K.J.; writing-review and editing, A.Z., K.B.; visualization, K.J.; supervision, A.Z. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
This study did not require ethical approval.  
Not applicable.  
The data supporting the findings of this study are available within the article.  
The authors declare no conflict of interest.
# Fault Studies and Distance Protection of Transmission Lines Connected to DFIG-Based Wind Farms
## 2 Fault Analysis of DFIG-Based Wind Farm and Its Verification
### Application of Conventional Distance Protection  
Distance protection exploits the fact that the voltage and current change at the same time when a fault occurs. The ratio of the measured voltage to the measured current represents the distance from the fault point to the relay location. The distance protection initiates if the fault distance is less than the setting value. For a conventional power grid with the synchronous generators, the measured voltages and currents in the relay location are mainly at nominal frequency. The Fourier algorithm is usually used to measure voltages and currents correctly. However, the short circuit currents of wind farm side may contain rotor speed frequency AC components, which cannot be filtered accurately. As a result, the calculation result error using the Fourier algorithm may be significantly large [34]. Then, the reliability of the distance protection based on nominal frequency voltage and current cannot be guaranteed. According to the real fault cases for phase-to-ground fault and phase-to-phase fault, the applicability of distance protection of the transmission line is analyzed.
# Response of Corroded Steel Pipeline Without and with CFRP Reinforcement to Reverse Fault Movement
## 4 Results and Analyses
### Effectiveness of CFRP Reinforcement
#### 4.4.1 Design Conditions  
A 3D numerical model is established for a corroded pipeline crossing a reverse fault with dip angle \(\beta\) = 60\({}^{\circ}\), buried depth h = 2 m, and corrosion depth of 0.6 t (t = 0.0119 m) to investigate the effectiveness of different CFRP external winding reinforcement schemes on the mechanical response and the failure mode of the pipeline. The number of reinforced layers is either 4, 8, or 12, and the reinforcement lengths considered are 5 m, 10 m, 15 m, and 20 m.