esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Results and Discussions
### Alfacrux Digital Twin Pilot
#### 3.2.5 Communication Channel Modeling and Risk Analysis  
The elaboration of a detailed model for the communication link in both directions (uplink and downlink) is relevant to simulating adverse situations, which helps the planning and assessment of mission risks. Within the AlfaCrux scope, the joint use of a communication simulator and the digital twin framework allows the elaboration of worst-case scenarios and the testing of new features that can be added in future missions. The measurement and modeling of scintillation are particularly relevant for sub-GHz frequencies when ground stations are positioned at low latitudes. The effects of space weather in the planning of the AlfaCrux ultra-high frequency (UHF) communication system was previously analyzed, see [34] for more details, and should be further investigated considering now the in-orbit data and radio frequency signals received at the ground station.  
Currently, the simulation framework is the GNU Radio platform, where two diagram blocks implement distinct aspects of the link modeling. The first block focuses on the dynamic channel model, considering the satellite passage above the ground station. Within the visibility window, the simulator provides fundamental channel aspects for different orbit altitudes and frequencies, such as free space attenuation and Doppler frequency deviation. Following the ITU-Regulations (ITU-R) recommendations, the insertion of channel impairments from the troposphere (such as attenuation from gases, rain, and clouds) and ionosphere (such as scintillation, Faraday rotation, and propagation delay) is currently under development. At the transmitting and receiving nodes, we also consider local parameters such as antenna gain-to-noise-temperature (\(G/T\)), transmitted power, Effective  
Figure 12: User segment architecture: data management and viewer.  
Isotropic Radiated Power (EIRP), and equivalent noise temperature of the receiver. In this block, the simulator updates the satellite position (and its effects on the channel) once a second.  
The second block diagram simulates the GMSK digital transmission in baseband under controlled conditions of signal-to-noise ratio. The simulation rate is milliseconds, and dynamical channel effects are considered here under the assumption of slow changes in the channel. With this module, it is possible to apply different techniques in the receiver chain, such as carrier/symbol synchronization, robust error-correcting codes, and advanced digital signal processing methods. This module also allows future prototyping by embedding the algorithms in a parallel software-defined radio platform.
## 3 Data and Methods
### Geo-Statistical Analysis  
Due to the complexity of our hypothesis and the heterogeneity of the studied area, the statistical correlation between TRD\({}_{\text{SDLUI}}\) and RD\({}_{\text{FFPI}}\) indicators was explored using a geographically weighted regression ([PERSON] et al., 2019). This method was chosen instead of using ordinary least squares (OLS), in spite of the reduced number of variables (only two), since the value of the Akaike information criterion ([PERSON] et al., 2019) for GWR was inferior to OLS, suggesting a better suitability for the GWR ([PERSON] et al., 2019). When performing the GWR analysis, a moving window including 30 neighbours was applied, with the correlation coefficient being separately calculated for each of the 627 cells of the grid, taking into consideration only 30 neighbour cells. The spatial distribution of Pearson's correlation coefficient and two-tailed probabilities for each class of values was obtained by means of the GWR. Subsequently, Moran's I for the spatial autocorrelation ([PERSON] et al., 2019) was performed for the residuals.
# Combination of Permanent and Variable Load Is Dependent
###### Abstract  
This study concerns the combination of the permanent and the variable loads in the structural design. The Eurocodes are used as a reference. Three new findings are presented: (1) In each physical structure, and in every load pair of the permanent load and the variable load, the maximum variable load is the service time load, the 50-year load, i.e., the high value of the variable load. Therefore, no load reduction should be applied in the combination. (2) The governing hypothesis is the independent load combination (ILC) with random load pairs and random single loads. However, the load pairs are not independent as normally one variable load occurs simultaneously in multiple structures and in multiple load pairs inducing correlation between the loads, ultimately full correlation, and the dependent load combination (DLC). (3) In the current Eurocodes, the design load combination applies to one load pair only. However, one design load combination virtually always applies to multiple load pairs which demands using the DLC. The authors have explained earlier that the permanent and variable loads should be combined dependently as the ILC contradicts the physics. The new findings support this conclusion. Changing the current codes towards the DLC approach would simplify them and eases their use in the structural design work.  
Keywords:load combination; structural design; code +
Footnote †: journal: Applied
## 3 Results and Discussion
\(\alpha\) can be deployed to calculate by the following equation:  
\[T=exp(-\alpha d) \tag{5}\]  
In the equation, \(T\) represents the transmittance and \(d\) stands for film thickness. The optical band gap of GaN can be obtained from the plot \((\alpha hv)^{2}\) vs. \(hv\) in Figure 6. Prolong the tangent line to energy axis and the value of the intersection exactly becomes the band gap \(E_{\text{g}}\). From Figure 6, the band gap \(E_{\text{g}}\) of the GaN on striped PSS is estimated to be 3.43 eV. For stoichiometric GaN films, the optical band gap used to be about 3.4 eV. Hence, the result is consistent with the result of Raman measurements and it also appears a red shift which gives evidence for the GaN films grown on striped PSS having higher crystallinity. Figure 5: Raman spectra of GaN-based LED films grown on striped PSS and planar substrate.
## 2 Modelling and Methods  
### Masonry Wall Assembly Finite Element (FE) Models  
#### 2.1.1 Geometrical Features of Models' Components  
The training of the ANN algorithm was based on data extracted from 30 different wall assembly FE models. Despite having a core model onto which the structure of the wall samples was founded, a range of variables was incorporated to enable a more accurate representation of the phenomenon of heat transfer through the wall samples. This pluralism also enhanced the understanding of the impact of various parameters on the process, through the use of ANNs in the following stages of the study.  
The foundation model involved the use of a single skin of perforated clay bricks stacked with cement bedding mortar. In the simplest modelling case, either face of this brick core was covered with a single layer of cement render before it was exposed to fire on one side (details regarding the boundary conditions and fire load applied to the model are included in the following paragraphs). Specifically, the masonry core consisted of 250 mm wd \(\times\) 140 mm dp \(\times\) 330 mm lg clay bricks incorporating an array of 18 full-length holes (12 holes of 26 mm \(\times\) 34.7 mm and 6 more elongated holes of 26 mm \(\times\) 56 mm), as indicated by the following sections in Figure 3. The bedding mortar and cement render were consistently 10 mm thick.  
Two variations of this basic matrix model were then developed and analysed; namely, a brick wall insulated with EPS internally (exposed to fire) and a brick wall insulated with EPS externally (non-exposed face of the wall). For each case, two EPS layer thicknesses were analysed: 50 mm and 100 mm.
## 5 DEADS: The Proposed Scheme
### Sink Mobility
#### 5.2.2 Elliptical Mobility Pattern  
Each MS follow an elliptical mobility pattern (with vertical major-axis) represented by equation:  
\[(x/b)^{2}+(y/a)^{2}=1 \tag{23}\]  
MSs move either Clock-Wise (\(CW\)) or Counter Clock-Wise (\(CCW\)) to cover the entire network. MSs change their position after regular time interval. New position of MSs represented by their \(x\) and \(y\) dimensions is given by:  
\[x_{MS_{CW,CCW}}=x_{o}+a\times cos(\theta) \tag{24}\]  
\[y_{MS_{CW,CCW}}=y_{o}+b\times sin(\theta) \tag{25}\]  
Figure 8 shows the elliptical mobility path followed by each MS. \(x_{o}\) and \(y_{o}\) represent the center coordinates of each elliptical path which are the same for each ellipse. \(a\) and \(b\) represent semi-major and semi-minor axis of each elliptical pattern, where; \(a=2b\). Values of \(a\) and \(b\) are different for each elliptical path. \(\theta\) represents the angle which is varied for clock-wise or counter clock-wise movement. After each predefined time interval, \(\theta\) is incremented or decremented by a certain value for counter clock-wise or clock-wise movement of MSs. Value of \(\theta\) can be adjusted according to the network requirements. Figure 9 shows data routing in the network in which MSs follow an elliptical mobility pattern. Data is routed from high depth to low depth region according to the rules defined in Section 4. All the nodes find \(d_{th}\), find appropriate \(CC\) or \(R\), \(DS\) or \(D\) nodes and then forward data by using cooperative manner. Nodes forward data by using either DEADS-SRC or DEADS-MRC. As shown in Figure 9, node \(D\) and \(F\) are forwarding data towards the preselected next-hop (\(DS\) or \(D\)) node via MRC, whereas, node \(E\) forwards data directly towards MS via SRC.  
Figure 8: Specifications of elliptical mobility path followed by MSs.
###### Abstract
In addition, the assessment of bearing capacity degradation was mostly performed based on experiments, lacking in-depth theoretical model representation and engineering guidance value. Therefore, it is still a focus in this field to reveal the failure mode and mechanism of RC beams with cracks and to quantify the calculation law of bearing capacity degradation. In this paper, stepwise static loading tests were performed on seven reinforced concrete T-beams. The cracks with different characteristics were prefabricated at the mid-span or one-quarter position of the bottom beam, to invert the distribution of cracks. The influences of crack location, crack depth and steel bar diameter on the stress, deflection and crack distribution pattern of pre-cracked beams were investigated. Next, the failure mode and mechanism of the pre-cracked test beam under load were revealed. The influence of prefabricated cracks on the bearing capacity of the beam was compared and quantified. Based on the test results, the FE numerical simulation method of the pre-cracked test beam was developed and validated. Following that, a theoretical prediction method was proposed to calculate the ultimate load of the pre-cracked RC beam. Finally, some conclusions were drawn.
## 3 Proposed Architecture
### Privacy and Trust Support  
One of the key motivations behind this architecture has been to enable privacy and trust. This done via two means:  
Identity Validation Component: The VIS has an identity validation component owned by specific provider that validates identities, which may not go as far as identification, but may be content with the validation of attributes or claims that the end-points must fulfill. The provider is thus able to assess whether or not the end-points are valid, thus providing an important barrier to phishing attacks. Of course, this depends on the provider itself being trustworthy and certified. This validation component will communicate via the Alpha API, is designed to communicate with a wide range of Identity Management systems, and is open to enhancements to cope with new developments in Identity Management. Validations are performed using Identity Management protocols that guarantee privacy e.g., using pseudonyms. To each identity in a domain, a different local identifier is used and mapped at the borders using a name resolution mechanism built into the IDM platform. A partial recovery of the data and identification of the user can be perform by the correlation of the pseudonyms at the different domains, which allows for legal interception and fulfills other regulatory requirements without compromising privacy on the day to day operations. Attribute based access control will support the setting up of connections.  
Path Validation Component: Not all the routers and nodes that are used by the VIS are necessarily owned by the provider of the VIS. This component will communicate via the Gamma API and need to check the identity of the nodes and their trustworthiness. As above, Identity Management protocols will be used to negotiate the security parameters related to the VIS for each particular communication. Identities of the network entities of a VIS, and their policies, are parameters that will need negotiation. Based on these results, the setup of the VIS will adjust which nodes have access to the transported data including end-point addresses, and which do not. As the internal end-points of the VIS themselves may not be (fully) trusted, the user will be notified about the level of trust that should be assumed and what levels of assurance exist.  
For both the trustworthiness of end-points of a communication, e.g., services, as well as for the trustworthiness of internal nodes and routers, hierarchical schemes, such as via certification authorities, as well as reputation systems may be used, such as those proposed in [21]. Security functions willensure the necessary privacy, and prevent an uncontrolled disclosure of identity data. Cryptographic techniques regarding private information retrieval may be applied [22, 23].  
While we have focused on the privacy and trust components, others will be supported, see Figure 1, such as dealing with access control and resource allocation, both of which are not dealt with here.
## 3 Applications and Limits of ATPs in Water and Wastewater Treatment
### ATP Efficiency Enhancement and Process Combination
The combination of EB irradiation and ozone (3 ppm) resulted in an eightfold reduction of the required dose for 95% trichloroethylene removal from contaminated groundwater, increasing the equipment irradiation capacity from 146 to 1200 m\({}^{3}\)/h while reducing treatment costs threefold from 0.25 to 0.075 US/m\({}^{3}\)[98]. A hybrid process combining microfiltration membrane separation with EB irradiation was tested for the production of safe water from secondary effluents. The EB's high effectiveness in modifying the effluent organic matter structure significantly reduced membrane fouling and improved permeate quality at an irradiation dose of 1 kGy, without significantly changing the overall process energetic consumption [99]. Hybrid radiolytic approaches (coagulation, biological treatment, and \(\gamma\)-irradiation) were tested for the decomposition of real pharmaceutical wastewater. The sequence of coagulation, irradiation, and biological treatment accounted for synergistic degradation and detoxification of recalcitrant pharmaceutical wastewater, with an overall improved COD removal at over 90% [100]. The study confirmed that irradiation pre-treatment is a realistic approach for the treatment of recalcitrant wastewaters. In particular, due to the very short process contact time, EB-based AORPs do not require large additional units, and can therefore be easily inserted in existing facilities' treatment trains with minimal disruption, to improve treatment efficiency.
###### Abstract  
In order to improve the concealment and security of a point-to-point transparent forwarding satellite communication system, a signal structure based on aperiodic long code spread spectrum is designed in this paper. This structure can achieve reliable signal acquisition without special physical layer synchronization overhead, which can effectively shorten signal transmission time and improve the concealment of communication. In addition, the performance of burst spread spectrum signal acquisition is analyzed in detail by establishing a mathematical model, and the influencing factors and design criteria of the matching filter length for aperiodic long code acquisition are determined. On this basis, a matched filter acquisition method based on high-power clock multiplexing and an adaptive decision threshold design method based on an auxiliary channel are proposed. The above methods effectively reduce hardware complexity and resource consumption caused by long code acquisition, and realize reliable acquisition under the condition of low SNR. The simulation results show that under the condition of Eb/N0 = 3 dB, the transmission efficiency for a 128-symbol burst frame can be increased by 50%, thereby significantly reducing the burst communication time. Furthermore, the acquisition success probability can reach 99.99%.  
burst spread spectrum; no synchronization overhead; acquisition; adaptive threshold Article
# The Outdoor Field Test and Energy Yield Model of the Four-Terminal on Si Tandem PV Module
## 4 Discussion
### Regional Difference in the Behavior of 4T and 2T Performance  
The fact that the annual change is affected by water precipitation implies that the gain by 4T configuration may be strongly influenced by the local climate.  
With the validation of the MS2E model in the estimation of PV output, we applied it more broadly. The solar database METPV-11 [104; 105] has a solar irradiance measurement dataset for more than 800 sites in Japan. We examined the seasonal energy yields in various locations with different climates. For the determination of the atmospheric parameters, measurement data of the solar spectrum are needed. NEDO (New Energy and Industrial Technology Development Organization) classified Japan into five different solar radiation climate zones to clarify regional differences in solar irradiation conditions. The global solar spectrum was monitored at five sites, including Naganuma (subarctic zone), Tosu (temperate zone), and Okinoerabu (subtropical zone). We extracted aerosol density and water precipitation in each solar radiation climate zone. Correctly, the aerosol density and water precipitation were derived using a model in Equations (1) and (2) that minimizes the deviation of the global spectrum between the experimental values measured and the model values. Note that the estimated global spectrum is a function of the variables of aerosol density and water precipitation [97].  
The result is shown in Figure 8. From the left to the right column, with the transition from the subarctic zone, to the temperate zone, and subtropical zone, water precipitation, which was calculated by optical absorption of the spectrum using the method mentioned above, increased. The gain of 4T configuration (\(R_{pp}\) value) increased accordingly.
# A Phase Correlation Anti-Noise Displacement Estimation Method Based on PSD Phase Screening
## 3 Experiment and Analysis
### Simulation Experiment  
#### 3.1.1 Experimental Data  
Six sets of panchromatic images with iron texture, cement texture, and soil texture, respectively, were captured, and the distance between the camera and the objects is around 10 m. The subpixel displacement was simulated, and noise was added by the following processing steps (as shown in Figure 7): (1) These images were cropped in the upper-left-corner area and the lower-right-corner area separately, and then two images with integer pixel displacement were obtained. The integer pixel displacement simulated is \(\mathrm{x}^{\prime}_{0}=-11\) pixels and \(\mathrm{y}^{\prime}_{0}=-21\) pixels. (2) The two images were down-sampled at the same ratio, the down-sampling ratio was set to 0.5 in this paper, and then two images with sub-pixel displacement were obtained. The simulated displacement was \(\mathrm{x}_{0}=-5.5\) pixels and \(\mathrm{y}_{0}=-10.5\) pixels, and the size of each image after processing was 502 \(\times\) 634. (3) Gaussian noise was added to each image separately to complete the data production of the simulation experiment. The added Gaussian noise has a mean value of 0 and a variance \(\sigma=255\times 5\%=12.75\) pixels.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Sensor & 1/2.7” CMOS \\ Shutter type & Global shutter \\ Camera type & Black and white \\ Pixel size & 4.0 \(\times\) 4.0 \(\upmu\)m \\ Effective pixels & 1.3 million \\ Resolution at frame rate & 1280 \(\times\) 1024 at 245 FPS \\ Pixel bit depth & 8 bit \\ Data interface & USB 3.0 Type B \\ \hline \hline \end{tabular}
\end{table}
Table 1: The parameters of the camera.  
The simulated data obtained after these steps are shown in Figure 8, where (a) and (d) are iron textures, (b) and (e) are cement textures, and (c) and (f) are soil textures. It can be seen that the images used for the simulation experiment are seriously disturbed by noise, which makes it indeed challenging to estimate the displacement.
## 3 Numerical Algorithm
### The Crank-Nicolson (CN) Method  
The Crank-Nicolson method is a second-order accurate scheme in both time and space. It utilizes the time average of the flux and source terms together with the centered spatial discretizations. Along with these principles, the governing equation yields  
Figure 2: A staggered grid cell (**left**) and a solution representation (**right**).  
\[\frac{c_{i,j}^{n+1}-c_{i,j}^{n}}{\Delta t} - \frac{1}{2}\left(\frac{D_{i+\frac{1}{2},j}c_{x;i+\frac{1}{2},j}^{n+ 1}-D_{i-\frac{1}{2},j}c_{x;i-\frac{1}{2},j}^{n+1}}{\Delta x}+\frac{D_{i+\frac{1 }{2},j}c_{x;i+\frac{1}{2},j}^{n}-D_{i-\frac{1}{2},j}c_{x;i-\frac{1}{2},j}^{n}}{ \Delta x}\right) \tag{8}\] \[- \frac{1}{2}\left(\frac{D_{i;j+\frac{1}{2}}c_{y;i+\frac{1}{2}}^{n+ 1}-D_{i,j-\frac{1}{2}}c_{y;i,j-\frac{1}{2}}^{n+1}}{\Delta y}+\frac{D_{i,j+\frac {1}{2}}c_{y,i,j+\frac{1}{2}}^{n}-D_{i,j-\frac{1}{2}}c_{y,i,j-\frac{1}{2}}^{n}} {\Delta y}\right)\] \[- \frac{1}{2}\left(\rho c_{i,j}^{n+1}\left(1-\frac{c_{i,j}^{n+1}}{c _{\max}}\right)+\rho c_{i,j}^{n}\left(1-\frac{c_{i,j}^{n}}{c_{\max}}\right) \right)\approx 0.\]  
Equations (6) and (8) can be viewed as a system of nonlinear algebraic equations (e.g., \(\mathbf{F}(c)\approx~{}0\)) that need to be solved for the unknown \(c^{n+1}\). The resulting nonlinear equation system will be solved using the Jacobian-free Newton Krylov (JFNK) method [20; 31; 34]. After applying a desired number of nonlinear iterations, the JFNK method guarantees the convergence of all nonlinearities in the system. Of course, we have to keep in mind that, in order for the JFNK method--just like the other nonlinear solvers--to converge to a physically correct solution, we have to provide a good initial guess. This is not an issue here, because we are solving an initial value problem. In other words, at the beginning of each time update, we have a very good initial guess coming from the previous time step solution.