esa-sceva/satcom-chunk-collection huggingface dataset:
# Minimizing Interference-to-Signal Ratios in Multi-Cell Telecommunication Networks
###### Abstract
However, the two sets of agents typically have different cardinalities, and their elements have very different functions and properties in the network. In this paper, we propose a simple and fast clustering algorithm to deal with the cell-edge problem. (An earlier version of this algorithm was reported in [19]). Our algorithm runs significantly faster than the spectral clustering method, and simulations on synthetic instances indicate that our proposed method typically provides higher quality solutions than the application of the spectral clustering method in [3]. In contrast with the spectral clustering methods, our proposed heuristic method is deterministic. We divide the interference minimization problem into three subproblems. In the first phase, a new, so-called _dot-product similarity measure_ is introduced on pairs of base stations. This similarity measure is based on the dynamically changing signal strengths between the users and the base stations. The two subsequent phases are two clustering problems. The second phase partitions the base stations into clusters, and the third phase assigns the users to base station clusters. The solution to the whole problem is given as a pairing between the base station clusters and user clusters. Our reason for this handling is the following observation: the roles of the base stations and the users are different, and so they require different considerations. We emphasize this asymmetry with our notation system as well. The clusters of the entire system appear as pairs of clusters: one on the index set of base stations, and one on the index set of the users; cluster classes of the same subscript serve together as a cluster class of the entire system. The _novelty_ of our method, which is responsible for the superior performance, lies in the usage of the dynamical similarity function between the base stations. The second and third phases can use off-the-shelf clustering algorithms, which can allow possible further fine-tuning of our method.
# Effect of Corrosion Characteristics on Long-Term Aging of Austenitic 304 Steel
## 4 Conclusions  
The effect of long-term aging of austenitic 304 steel on electrochemical corrosion characteristics has been investigated at a temperature of 700 \({}^{\circ}\)C for up to 10,000 h. The following conclusions were drawn:  
1. As the aging progresses for a long time, the metastable intermetallic M\({}_{23}\)C\({}_{6}\) carbides generated in the vicinity of \(\gamma\)/\(\gamma\) grain boundaries and coarsened with aging time. In addition to the grain boundary, the intermetallic phases also generated within the grain interior.
2. The \(\delta\)-ferrite decomposed into \(\sigma\)-phase, and M\({}_{23}\)C\({}_{6}\) carbide with an aging time increase. This dissolution of \(\delta\)-ferrite was mainly attributed to the excess Cr depletion in the \(\delta\)-ferrite and \(\gamma\)/\(\delta\) interface resulting from the Cr carbide precipitation.
3. The \(\delta\)-ferrite phase can be decomposed into \(\sigma\)-phase and M\({}_{23}\)C\({}_{6}\) carbide in austenitic stainless steels, but the X-ray diffraction analysis showed an increased ferrite peak. It may be due to chromium depletion due to prolonged degradation and sensitization-induced martensite near the grain boundaries.
4. As the aging time increased, the current density increased, but the corrosion potential of the austenitized specimen exhibited a minimum value of 0.04 uA/cm\({}^{2}\) due to the not enough sensitization. Easier passivation was observed until 1000 h aging, and the highest pitting resistance was exhibited by the austenitized specimen due to the absence of carbides.  
**Author Contributions:** [PERSON], [PERSON], and [PERSON] carried out the experiment. [PERSON] wrote the manuscript with support from [PERSON] and M.K. [PERSON] conceived the original idea and supervised the project.  
**Funding:** This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 2017R1D1A3B03028681).  
**Conflicts of Interest:** The authors declare no conflict of interest.
## 3 Influence Factors of \(R_{s}\)
### Influence of Environmental Factors on \(R_{s}\)
#### 3.1.6 Biofouling  
When passive sampler was deployed in waterbody, biofilm layers (microorganisms, plants, algae, or animals) might be formed on the filter membrane surface, resulting in biofouling [86]. Several studies suggested that the biofouling layer could be described as the water layer with dispersed organic matter [87; 88; 89], and the mass transport coefficient (\(k_{b}\)) for this layer was given as:  
\[k_{b}K_{bw}=\frac{\Phi^{2}D_{w}}{\theta\delta_{b}} \tag{14}\]  
where \(\delta_{b}\) is the effective thickness of biofilm and other parameters referred to in Equation (8). This equation indicated that the biofilm was similar to an immobilized water layer and the \(k_{b}\) value was independent on the \(K_{bw}\).  
The biofouling layer had an inhibitory effect on the diffusion of analyte, and thus impacted the \(R_{s}\) of target analyte through an increased biofilm layer with deployed time [90]. This phenomenon might be explained by the facts that the filter membrane pores were physically clogged by biofilm [91; 92] and interfacial physical-chemical reactions occurred between algae, metal oxides, dissolved substance, and the analyte on the membrane surface [93; 93].  
Nevertheless, a different view was proposed by some researchers [86; 87; 94; 95], who showed an insignificant effect of biofouling on the \(R_{s}\) for more compounds, especially for hydrophilic compounds. In those publications, the biofilm was regarded as a water layer with dispersed organic matter, and the hydrophilic compounds could permeate this layer faster.  
The error of \(R_{s}\) caused by biofouling can be corrected by a mathematical model (as shown in Equation (14)) simulating the impact of biofouling on the mass transfer of pollutants, as well as by performance reference compounds (PRCs) as an effective calibration method, correcting the impact of biological pollution.
## 3 Triangular Calculus
\begin{split} g(x)\cdot(1-(y/x)^{q})&=(p\epsilon g (x))^{1/p}\cdot\left(\frac{(g(x))^{1/q}(1-(y/x)^{q})}{(p\epsilon)^{1/p}} \right)\\ &\leq\epsilon g(x)+\frac{g(x)(1-(y/x)^{q})^{q}}{q(p\epsilon)^{q/p }}\end{split}  \tag{13}\]  
where the inequality is by [PERSON]'s inequality \(ab\leq\frac{a^{p}}{p}+\frac{b^{q}}{q}\) for every \(a,b\geq 0\) and \(p,q>0\) such that \(1/p+1/q=1\). We then obtain (12) by substituting \(\phi=(q-1)^{q-1}/\varepsilon^{q-1}\) so that  
\[\frac{\phi}{q^{q}}=\frac{(q-1)^{q-1}}{q(q\epsilon)^{q-1}}=\frac{1}{q(p \epsilon)^{q/p}}.\]  
Next, we bound the rightmost expression of (12). We have \(1-w^{q}\leq q(1-w)\) for every \(w\geq 0\), since the linear function \(q(1-w)\) over \(w\geq 0\) is tangent to the concave function \(1-w^{q}\) at the point \(w=1\), which is their only intersection point. By substituting \(w=y/x\) we obtain  
\[1-(y/x)^{q}\leq q(1-y/x). \tag{14}\]  
By the triangle inequality,  
\[1-y/x=\frac{x-y}{x}\leq\frac{z}{x}. \tag{15}\]  
Combining (14) and (15) yields  
\[(1-(y/x)^{q})^{q}\leq(q(1-y/x))^{q}\leq q^{q}(z/x)^{q}. \tag{16}\]  
Since \(g(x)\geq\phi g(z)\geq g(z)\) by (10) and the definition of \(\phi\), we have \(x\geq z\), i.e., \((x/z)\geq 1\) by the monotonicity of \(g\). Hence, \(g(x)=g(z\cdot x/z)\leq g(z)\cdot(x/z)^{r}\leq g(z)\cdot(x/z)^{q}\) by (5), so  
\[(z/x)^{q}\leq g(z)/g(x). \tag{17}\]  
By combining the last inequalities we obtain the desired result  
\[g(x)-g(y) \leq g(x)\cdot(1-(y/x)^{q}) \tag{18}\] \[\leq\epsilon g(x)+\frac{\phi g(x)(1-(y/x)^{q})^{q}}{q^{q}}\] (19) \[\leq\epsilon g(x)+\phi g(x)(z/x)^{q}\] (20) \[\leq\epsilon g(x)+\phi g(z), \tag{21}\]  
where (18) holds by (11), (19) is by (12), (20) holds by (16), and (21) is by (17).
# Assessing the Security and Privacy of Baby Monitor Apps
## 5 Mobile App Analysis
### Assessing the Confidentiality of Video Streams
#### 5.6.1 Static Code Analysis  
Performing automated static code analysis supports security evaluation by providing an overview of possible security issues, guiding further analysis, and identifying evident flaws. We performed the static analysis using MobSF [27] and investigated the issues found by performing a manual code review. The results produced by MobSF indicate a broad surface of possible issues, which are listed in Table 10. However, only a few of them could impact the confidentiality of video streams. The most relevant security issue threatening video confidentiality is the Insecure Implementation of SSL issue in the Saby app. However, we could not confirm this security issue during manual code analysis, so we assume a false-positive report. The same holds true for insecure random number generator issues as well as hard-coded passwords.  
In contradiction, findings indicating the use of further vulnerable cryptographic primitives, e.g., the usage of MD5 or SHA1 hash functions or PKCS5 padding, are true-positive security issues. As they do not have a negative impact on video confidentiality, we leave the investigation of their impact open for future work. Our code review shows similar findings for the execution of raw SQL queries and the enabling of code execution in WebView implementations, which are not in the scope of this study. We document our results in Table 10, which shows that none of the issues identified during the static analysis threatens the confidentiality of the monitor streams.  
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**App** & **Data Encryption** & **Key Exchange** & **Peer Authentication** \\ \hline Dormi & End-to-End (SRTP) & Proprietary & Anti-tamper code \\ BabyCam & - & Password (optional) \\ Saby & End-to-End (SRTP) & DTLS & Certificate hash \\ Babyphone Mobile & TLS & TLS & TLS Certificate \\  & End-to-End (optional) & User (Password) & - \\ \hline \hline \end{tabular}
\end{table}
Table 9: Identified network security measures in the inspected apps.  
Figure 6: Dormi app: identify verification using an anti-tamper code exchanged during pairing.
# A Robust Dual-Platform GMTI Method against Nonuniform Clutter
## 2 The Dual-Platform GMTI Method against Nonuniform Environment  
Firstly, this section briefly sets out the basic formulation of the problem, and then analyzes and quantifies the influence of the heterogeneous environment in STAP. Finally, the high-accuracy clutter covariance matrix estimation, based on a dual-platform SAR system, is explored.
# Automated Generation of Daily Evacuation Paths in 4D BIM
## 1 Introduction
One of the promising BIM applications is 4-Dimensional Building Information Model (4D BIM) that merges construction schedule information into a 3D BIM environment. 4D BIM is considered one of the most advanced ways to digitally represent, not only dynamically changing construction sites, but also constantly shifting construction working conditions through the construction timeline. In addition, since BIM generally entails resources and information of relevant objects and relationships, professionals in the construction industry are able to integrate indispensable construction data into one consolidated platform and manipulate them for distinct purposes during the construction phase. With its time-dependent and realistic visualization, various moving paths (e.g., evacuation, site entrance, material delivery) can be planned on top of the 4D BIM platform. However, the benefits of current 4D BIM applications and analysis are still limited to the visualization of expected construction site conditions. Since 4D BIM can explicitly represent construction processes with associated resources based on a planned schedule, it is a desirable approach to plan work procedures, work crews' paths, and evacuation scenarios according to a planned schedule. However, it can be extremely labor-intensive for project managers to manually analyze complex 4D BIM to establish path plans for multiple work crews and different purposes (entrance, material delivery, evacuation) on a daily basis. Unfortunately, even though several 4D BIM applications have been proposed for daily safety hazard identification [2; 3], path planning within 4D BIM has been overlooked. From this perspective, there is a need for BIM-based automation that generates evacuation paths throughout the construction processes. This research presents a method to automatically generate rational evacuation paths of multiple crews using information in 4D BIM. The analyzed paths according to dynamic site conditions and changing construction progress will be valuable assets for field managers and the workforce to secure guaranteed pathways and accessible spaces. This paper is organized as follows. The literature review section presents a review of state-of-the-art approaches in the area of 4D BIM-based automated analysis and BIM-based construction path generation. A point of departure, a research objective, and a study scope are presented. The next section presents the framework and algorithms of the proposed evacuation path generation in 4D BIM. The case study section presents a validation in BIM of a real-world construction project and the benefit section contains the expected applications and advantages. The conclusions and discussion section presents the conclusion, limitations, and suggestion for future studies.
###### Abstract  
In recent years, with the growing interest in the Internet of Things (IoT) and decarbonization, energy harvesting has been attracting attention. Energy harvesting is a technology that converts ambient energy such as light, heat, and vibration into electrical power, and it is also known as environmental power generation. A triboelectric nanogenerator is a type of energy harvesting device that converts mechanical energy, such as vibration, into electrical energy using the triboelectric effect and electrostatic induction. The advantages of this device include low cost and high durability. Due to the principle of triboelectric nanogenerators, a stable output voltage cannot be obtained, so auxiliary circuits such as DC-DC converters are required to obtain the desired voltage. In this paper, a DC-DC converter is utilized, controlled by a system based on operator theory, with a filter incorporated to enhance tracking performance, ensuring that the output voltage follows the target value.  
operator theory; nonlinear control; triboelectric nanogenerator; right coprime factorization; DC-DC converter; circuit model +
Footnote †: journal: Applied sciences
###### Abstract  
Traditional spaceborne Global Navigation Satellite Systems Reflectometry (GNSS-R) sea surface height (SSH) retrieval methods have the disadvantages of complicated error models, low retrieval accuracy, and difficulty using full DDM information. To compensate for these deficiencies while considering the heterogeneity of the input data, this paper proposes an end-to-end Modified Residual Multimodal Deep Learning (MRMDL) method that can utilize the entire range of DDM information. First, the MRMDL method is constructed based on the modified Residual Net (MRResNet) and Multi-Hidden layer neural network (MHL-NN). The MRResNet applicable to DDM structures is used to adaptively capture productive features of the full DDM and to convert the two-dimensional DDM data into one-dimensional numerical form. Then, the extracted features and auxiliary parameters are fused as the input data for MHL-NN to retrieve the SSH. Second, the reliability of the model is verified using SSH with tide-corrected DTU Sea Surface Height 18 (DTU18) and spaceborne radar altimeters (Jason3, HY-2C, HY-2B). Compared to the SSH provided by the DTU18 validation model and the spaceborne radar altimeter, the Pearson correlation coefficients (_PCC_) are 0.98 and 0.97, respectively. However, the CYGNSS satellite is not primarily employed for ocean altimetry, and the mean absolute differences (_MAD_) are 3.92 m and 4.32 m, respectively. Finally, the retrieval accuracy of the MRMDL method and the HALF retracking approach are compared and analyzed. Finally, this study also implements the HALF retracking algorithm to derive the SSH, and the results are compared with those computed by the MRMDL method. The MRMDL method is more accurate than the HALF retracking approach according to _MAD_, Root-Mean-Square Error (_RMSE_), and _PCC_, with an improvement of 35.21%, 17.25%, and 2.08%, respectively. The MRMDL method will contribute a new theoretical and methodological reference for future GNSS-R altimetry satellites with high spatiotemporal SSH retrieval.  
the new MRMDL model; MRResNet; spaceborne GNSS-R altimetry; CYGNSS spaceborne data; DTU18 validation model +
Footnote †: journal:  
00233
# Real-Time Rain Rate Evaluation via Satellite Downlink Signal Attenuation Measurement
## 4 Direct Method for the Estimation of the Rain Rate
### Rain Height
The red curve shows the raw data, the violet one plots the 0 \({}^{\circ}\)C isotherm height after some smoothing (i.e., low-pass data filtering), while the upper and lower curves are obtained by taking the smoothed average plus or minus one standard deviation of the measured data.
## 3 Experimental Results and Discussion
### Experimental Rig  
As shown in Figure 7, in order to obtain the relationship between the motion state of the debris and the induced voltage, one piece of ferromagnetic debris was attached to a nylon wire driven by a stepping motor. By manipulating the rotation speed of the motor or the radial height of the nylon thread, the wear debris can flow through the lube oil in the oil pipe at different velocities or with  
Figure 5: Variation of the angle \(\alpha\) over z-height.  
Figure 6: Simulation wave (0.5 mm \(\times\) 0.5 mm \(\times\) 0.5 mm iron debris, 1000 AN magnetic potential, 1 m/s).  
different radial positions. The voltage generated by the induction coil is weak, so an amplifier is installed between the sensor and PC to amplify the voltage signal output by the sensors.
# A Novel Drone Design Based on a Reconfigurable Unmanned Aerial Vehicle for Wildfire Management
## 3 Materials and Methods
### Use Case Scenarios  
In wildfire and prescribed fire sciences, a multipurpose UAV with the ability to accommodate multiple payloads and provide various operational technical specifications can be highly beneficial. Equipped with appropriate sensors, the drone can patrol vast forest areas to detect hotspots indicating the start of a wildfire. With thermal imaging, it can identify temperature anomalies imperceptible to the naked eye, enabling early intervention. Additionally, UAVs can provide real-time data for mapping affected areas, crucial for firefighters' containment strategies and scientists' understanding of fire behavior. In prescribed fire sciences, drones monitor controlled burns, ensuring they stay within designated boundaries and assessing their effectiveness in reducing fuel loads [32]. Drones can also transport equipment or supplies to firefighters in remote areas, reducing risk and  
Figure 2: High-level architecture of PULSAR UAV.  
expediting response times [33]. Through integrating drones into wildfire management and prescribed fire sciences, responders and researchers can comprehensively understand fire dynamics, enhance safety, and improve operational efficiency. Consequently, the UAV design presented in this article is intended to serve a variety of tasks with different payloads, including prospective missions such as small-scale fire extinguishing.
# Statistical Multipath Model Based on Experimental GNSS Data in Static Urban Canyon Environment
## 4 Statistical Model Analysis
### Multipath Fading Frequency
The blue solid line, blue dashed line and red solid line denote the mean fading frequency of the MEO, IGSO and GEO satellites, respectively. The mean fading frequency of the MEO multipath is the maximum. The mean fading frequency of the IGSO satellite is approximately half of that of MEO. In addition, the mean fading frequency of the GEO satellite is approximately one percent of that of NGEO (MEO and GEO). This implies that the variation period of observation error of the GEO satellite may last tens of minutes in most cases. Figure 14: Statistical probability distribution of multipath fading frequency for the GEO satellite. Figure 15: Mean of multipath fading frequency for different satellite orbits. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Elevation Range** & **(0, 15)** & **(15, 30)** & **(30, 45)** & **(45, 60)** & **(60, 75)** & **(75, 90)** \\ \hline MEO/\(\lambda\) & 17.2 & 12.3 & 10.9 & 10.6 & 11.2 & 12.8 \\ IGSO/\(\lambda\) & 90.9 & 23.8 & 18.5 & 20.4 & 27.0 & 41.7 \\ GEO/\(\lambda\) & & & 1495.9 & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Distribution parameter of multipath fading frequency.
# Photovoltaic Solar Cells: A Review
## 2 Solar Cells
### Materials Employed in PV Cells
#### 2.7.1 III-V PV Gallium Arsenide  
GaAs (III-V binary semiconductor), a widely used electronic semiconductor in solar cells, is a crystalline PV material based on an element with three valence electrons, gallium (Ga), and an element with five valence electrons, arsenic (As). Therefore, the average valency is four electrons per atom. GaAs has a zinc blend crystal structure that consists of four (As) neighbouring atoms with every (Ga) atom and four neighbours (Ga) with every (As) atom, referring to the Figure 8. It has a direct bandgap equal to 1.42 eV at room temperature (300 K) where the lowest conduction band is vertically aligned with the highest valence band [60]. Thus, no transfer of momentum is required to excite an electron from the valence to the conduction band [71]. GaAs has a high resistivity to heat and radiation that affect the module performance compared to (c-Si) solar cells. Double heterojunction GaAs solar cells achieved the highest energy conversion efficiency by [42; 72]. Many studies on single-junction GaAs cells achieved 28.8% power efficiency [54]. The highest efficiency of GaAs semiconductors was accomplished with a triple-junction, reaching up to 42.3%. However, the GaAs solar module is too expensive as gallium resources are limited [73]. Therefore, further improvement of higher efficiency and low-cost GaAs solar cells is significant in the PV solar system [74].