esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 System Model
### Polarization Modulation Model  
The polarization state of an electromagnetic wave is defined by the relative amplitude and phase of its horizontal and vertical components. To represent the polarization state of a completely polarized electromagnetic wave, the Jones vector is employed [36; 37]:  
\[E_{Jones}=\begin{bmatrix}\cos\varphi\\ \sin\gamma e^{j\varphi}\end{bmatrix} \tag{1}\]  
where \(\gamma\in[0,\frac{\pi}{2}],\ \varphi\in[0,2\pi].\ (\gamma,\varphi)\) represents phase descriptors.  
The Stokes vector representation is as follows [36; 37]:  
\[J=\begin{bmatrix}g_{0}\\ g_{1}\\ g_{2}\\ g_{3}\end{bmatrix}=\begin{bmatrix}1\\ \cos 2\chi\cos 2\psi\\ \cos 2\chi\sin 2\psi\\ \sin 2\psi\end{bmatrix}=\begin{bmatrix}1\\ \cos 2\gamma\\ \sin 2\gamma\cos\varphi\\ \sin 2\gamma\sin\varphi\end{bmatrix} \tag{2}\]  
where \((\chi,\psi)\) denotes a geometric descriptor. \(g_{0}\) represents the radius of the Poincare sphere, and \(g_{1}\), \(g_{2}\), and \(g_{3}\) correspond to the three coordinates of the polarization state in the Cartesian coordinate system. In particular, \(2\delta_{i}\) represents the arc length from the polarization constellation point \(P\) to \(P_{H}\). \(t_{i}\) and \(\varphi_{i}\) denote the longitude and latitude of \(P\) on the Poincare sphere, respectively. \(\phi_{i}\) is defined as the angle between the arc and the equatorial plane, as shown in Figure 1.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Technique** & **Security Domain(s)** & **Key Space Size** & \begin{tabular}{c} **Anti-Interception** \\ **Gain** \\ \end{tabular} & **Limitations** \\ \hline (DM) [34; 35] & Spatial & Low (direction) & Moderate & \
\begin{tabular}{c} Susceptible to multi-antenna \\ eavesdroppers \\ \end{tabular} \\ Artificial noise (AN) & Spatial & Moderate (direction + AN) & High &
\begin{tabular}{c} Reduces power efficiency; AN can \\ interfere with legitimate users \\ \end{tabular} \\ WMFRFT-based security [25] & Time-frequency (TF) & High (transform orders/vectors) & High & No spatial security; susceptible to frontal attack at the correct location \\ Our proposed scheme & Multi-domain & Very high (combined keys) & Very high (synergistic) & Increased system complexity \\ \hline \hline \end{tabular}
\end{table}
Table 1: Comparison of different physical layer security schemes.  
The polarization constellation points \(P_{i}(i=1,2,\ldots,M_{P})\) of order \(M_{p}\) are the parameters associated with the polarization phase descriptor, and \(P=\begin{bmatrix}w_{k}^{1}&w_{k}^{2}\end{bmatrix}^{T}\), where \(w_{k}^{1}\) and \(w_{k}^{2}\) are the weighting factors, as illustrated in Figure 2.
## 6 Evaluation
### Security  
In this section, we analyze our solution for some security concerns based on the amalgamated work of OWASP top ten (Open Worldwide Application Security Project) security threats for web applications and blockchain [29; 30]. Also, from the perspective of a smart contract, which, in our case, is an application-oriented blockchain based on a compiled substrate pallet, we analyze its concerns. Their analysis is as follows:  
* Injection: The blockchain systems can be compromised by using malicious data, which can be in the form of Integer Overflow or Batch Overflow [30]. We ensure adequate checks and balances in the system where external parameterized signed extrinsic are minimized except for encrypted bids.
* Access Control: Each participant of Vehicle_OEM, RADAR_OEM, Vehicle, and escrow is based on access control ensured through permission pallets and privileged calls as they are consortium-based, limiting risk exposure.  
* OffChain Manipulation: Our solution communicates with the OffChain only for retrieval and data job scheduling, not as an oracle for knowledge-based decisions that shield against manipulation attacks.
* Sensitive Data Exposure: Data on the blockchain are only related to the original blockchain accounts and their pseudonymized transactions. All the data are managed OffChain, which ensures that sensitive data are hidden and only managed by the blockchain trust mechanism.
* Smart Contract Security: In this application, our decision of smart contract deployment is not external and is compiled along with the node and executed along with its runtime. Further, the ERC 721 token specification of Ethereum is adapted for the Substrate FRAME library, and each logic is separated for token creation, OffChain data orchestration, as well as certification validation, which is tested for performance.  
The functional evaluation was performed by comparison with earlier mentioned works of Ocean Protocol and Digital Infrastructure for Moving Objects (DIMO) in Section 1. We have a consortium where data are exploited to create a mutual benefit among the ecosystem with a measure of balanced privacy, dynamic pricing, fidelity, transparency, certification, and value addition for the vehicle. It has no external dependency in the form of trusted computing or hardware wallets with integrated OffChain seamless interaction for managing and retrieving from external systems.
# Aerospace
## 6 Mars Small Satellite Constellation
### Mission Requirements  
The inclinations of the various satellites are arbitrarily selected for this study to illustrate targeting multiple orbits for a constellation but can easily be adapted to other orbits.  
1. The mission should insert a set of five 25 kg SmallSats to 200 \(\times\) 2000 km orbits with inclinations of 1.65 deg., 22.5 deg., 45 deg., 67.5 deg., 90 deg. as secondary payloads.
2. The total \(\Delta V\) available for the deflection maneuvers for small satellite targeting, and the final orbiter deflection maneuver is 25 m/s.
## 2 Materials and Methods
### Methodology  
Figure 2 presents the methodological framework and technical approach of this study, encompassing four main aspects:  
1. By combining multi-period remote sensing imagery with statistical yearbook data, this study classifies land-use categories within the territorial space of the Dongting Lake region and establishes a carbon source-sink indicator database.
2. The dynamic degree and transfer matrix models are applied to investigate the spatiotemporal evolution of the territorial space in the Dongting Lake region, identifying transition patterns across production, living, and ecological land-use categories.
3. Total carbon emissions and sequestration in the Dongting Lake region are estimated using the IPCC inventory's direct and indirect estimation methods alongside the energy coefficient. The study examines carbon budget patterns at both \"grid\" and \"city\" scales, analyzing their spatiotemporal trends, spatial differentiation, and clustering effects.
4. The Kaya identity is utilized to decompose carbon emissions in territorial space into five influencing factors: carbon emission intensity, land-use structure, land-use efficiency, economic development, and population size. Using the additive model of the LMDI decomposition method, the cumulative contributions of each factor to carbon emissions are quantified, providing insights into the intrinsic relationships between land-use functions and carbon budgets.
## 2 Materials and Methods
### Data Collection and Analysis  
In this study, data of daily maximum, minimum, mean temperature (T\({}_{\text{max}}\), T\({}_{\text{min}}\), T\({}_{\text{mean}}\), \({}^{\circ}\)C), diurnal temperature range (\(\Delta\)T, \({}^{\circ}\)C), total solar radiation (R\({}_{\text{a}}\), M) m\({}^{-2}\) d\({}^{-1}\)), actual sunshine duration (S, h), wind speed at 2 m height (U\({}_{2}\), m s\({}^{-1}\)) and relative humidity (RH, %), during the period of 2018-2020 were collected. After the data quality check by the CMA, the datasets were proved to have good continuity and accuracy.
# A Site-Specific Response Analysis: A Case Study in Hanoi, Vietnam
## 1 Introduction
The purpose of this study is to perform site-specific nonlinear (NL) and EQL response analyses based on the profiles from different locations of Central Hanoi City (Vietnam), using a range of input ground motions. The obtained spectra shapes are compared with those of the Vietnamese seismic design code, TCVN 9386:2012, and differences between NL and EQL methods are thoroughly discussed. Figure 1: Map of major faults in the north of Vietnam [3].
# Low-Cost Software Evaluation of Communication Delays in Networked Industrial Systems
## 4 Delay Measurement  
### I350 Packet Timestamping Capability  
The testbed developed to test the effectiveness of our measurement system leverages the I350's ability to timestamp packets on the transmit and receive paths of each port. Actually, the controller timestamps packets as specified by the IEEE 1588 [31] and 802.1 AS [32] Precision Time Protocol (PTP) standards. Hence, most parts of the \(TM\)'s design presented in this paper are applicable to other network controllers offering timestamping based on the same standards.  
Timestamps are taken from SYSTEM, a per-port 72 bit counter, and each counter is updated every 8 ns. SYSTEM is cleared when various forms of board- and port-level reset and initialization take place and, as a consequence, registers belonging to different ports hold different values at the same absolute time, because in a Linux system NIC ports are initialized in sequence at boot. Since there is no way to reliably read all SYSTEM registers at exactly the same time to determine their offsets once and for all, these differences must be compensated while correlating timestamps taken on different ports.  
When using the most basic timestamping mechanism, the hardware stores timestamps in a dedicated pair of per-port registers--one for the transmit and one for the receive path. These timestamps are latched, to prevent further timestamps from overwriting them until they are read by software. This mechanism is adequate when the goal is to support PTP exchanges, but is ill-suited for general-purpose packet timestamping because it makes timestamps hard to correlate with the corresponding packet. This is especially true when the software might not always be able to retrieve a timestamp before the next one is taken,leading the hardware to discard one or more timestamps when it tries to store them into a latched register.  
For this reason, the I350 implements an additional timestamp storage mechanism, available only on the receive path. Timestamps are still taken as before, but they are put in a dedicated header stored just before the Ethernet MAC header in the packet receive buffers. In this way, the hardware itself uniquely associates timestamps with packets without having to rely on stringent software timings. This is the mechanism used when most Linux tools ask for hardware-assisted timestamp on the I350, and this is also one main reason why only receive-path timestamps have been considered in this paper, leading to the introduction of \(n_{M}\) in Figure 1.
## 4 Experiment and Analysis
### Performance Test  
Finally, the performance of the platform is tested, whereby we use the average response time, load balancing, and communication delay to evaluate the performance of the system. The verification process is controlled through the control terminal, and manual operation is only carried out at the control terminal. Parameters are input to the exciter to generate the specified data, and data information is displayed on the display server as required. On the basis of this, we evaluate the performance in detail through the processing speed of tasks and the communication between components.  
1. Average response time and load balancing tests  
To offset the influence of data randomness on the test results, the response time is the average response time of the optimal solution obtained from 20 tests. In the flight management component, the calculation workload of the test task is between 1 MI and 100 MI, and the processing speed of the heterogeneous processor is between 10 MIPS and 100 MIPS. The number of heterogeneous processors is 10, 20, 30, and 40, respectively. The task size is generated from the uniform distribution. When the number of tasks is 50, 100, 150, 200, 250, 300, 350, 400, 450, and 500, respectively, the first come first service strategy is utilized to obtain the average response time (as shown in Figure 11) and the load of the system (as shown in Figure 12), and the analysis of test results is shown in Table 1. Here, we use the standard deviation (stdev) of load balancing as the degree of load balancing in avionics systems. The larger the standard deviation is, the more unbalanced the load distributions of avionics systems become. The test results show that the system has a good response speed. However, the load balancing is slightly poor. This is because we need to process tasks quickly rather than pursuing load balancing in avionics systems.  
2. Communication delay testing  
We evaluate the performance of communication by sending and receiving ICD messages between the two components. The size of the packet is 32 bytes, 64 bytes, 128 bytes, and 256 bytes, respectively, and the number of tests is 10, including data interaction between flight management components and flight control components, and data interaction  
Figure 10: Dynamic display of the display server when flying height is 10,000 m.
# Adaptive Pitch Controller of a Large-Scale Wind Turbine Using Multi-Objective Optimization
## 3 Control Methodology
### Description of the Control Blocks
#### 3.2.2 Adaptive Feedforward Compensation  
Adaptive feedforward control is performed based on the multiple linear models identified previously in (13) and (14). Depending on the wind speed v\({}_{\mathrm{w}}\) and generator speed \(\omega_{\mathrm{g}}\), the value of the gain and time constant of the dynamics G\({}_{\omega\mathrm{g}}\)(s) and Gd\({}_{\omega\mathrm{g}}\)(s) are linearly modified, and then the transfer function of the feedforward compensator Ca(s) is updated and calculated according to (21). From the wind speed estimation, it provides the control action FF(k) of Equation (20) (or \(\beta_{\mathrm{FF}}\) signal in the proposed control scheme in Figure 3).  
\[\begin{array}{c}\mathrm{Ca(s)=\frac{-Gd_{\omega\mathrm{g}}(s)}{G_{\omega \mathrm{g}}(s)}=\frac{-\frac{K_{\omega}}{\mathrm{K_{\mathrm{g}}}+1}}{\frac{K_ {\omega}}{\mathrm{R}}+1}}\\ \mathrm{\beta_{FF}(s)=K_{ff}Ca(s)}\end{array} \tag{21}\]  
K\({}_{ff}\) is a gain to be tuned from 0 to 1 and is aimed to reduce the control action of the feedforward strategy depending on the operating point.  
Adaptive feedforward compensation (Ca) is designed for all possible operating points within the nominal zone. To cover this entire operating range, a linearization of both dynamics has been carried out in a pitch range from 0 to 25 degrees in intervals of 0.5 degrees and wind values from 11.5 to 24 m/s in intervals of 0.5 m/s. A linear interpolation of both dynamics is performed as a function of \(\omega_{\mathrm{g}}\) for each model. The parameters obtained from both dynamics as a function of \(\omega_{\mathrm{g}}\) and v\({}_{\mathrm{w}}\) are shown in Figure 5. The four parametersare updated in the adaptive controller through interpolations according to the wind speed and the generator speed.
## 4 Federated System
### Simulation Results
#### 4.3.2 Test 2--Three-Client System with Late Arrival  
After verifying the correct functioning of the federation process in Test 1, the second test focused on the implementation of a system with three clients, as shown in Figure 8. Two of these three clients join the system late: Client 1 arrives at the end of Round 1 and participates in the remaining aggregation rounds, while Client 3 does not participate in the aggregation rounds but arrives at the beginning of the last local training round and trains that model with the global model that the server sends at that time.  
This test was set up with 200 thousand local training steps for each of the five aggregation rounds implemented. Only Client 2 participated in all rounds and, as the results in Figure 9 show, it was not until after the third round that the model reached the desired convergence.  
Client 1 entered the system in Round 2 and started training with the model obtained by Client 1 after Round 1. Then, it started participating in the aggregation and, after two rounds, it managed to form a global model that obtained the maximum number of rewards.  
In the case of Client 3, it joined the system only at the beginning of the final round, during which it received the global model from the server and performed local training in Round 5. The results demonstrate that, after the global model had converged, Client 3 achieved the maximum reward during its training round.  
Figure 8: Federated system scenario (Test 2).
## 3 Fault Diagnosis
### FD Methods
#### 3.1.4 Hybrid Approaches  
A single FD method has its advantages and disadvantages and has different applications. There is no general FD method suitable for all the working conditions or scenarios. Therefore, the hybrid model takes into account the advantages of each model, realizes the complementarity between models, and then improves the diagnosis accuracy and decision rationality.  
The fusion of more than one FD method into a hybrid model may be realized in many ways. Physical model and data-driven approach are combined for rotating machinery FD and HP [111]. Since it is complicated to obtain the complete degradation data from the operating systems and equipment, the physical model simulation method can be used to simulate the actual operation condition and generate synthetic data. The combination of data simulation, through physical modeling, with both supervised and unsupervised Machine Learning methods has been examined with application to system decay in naval vessels [7; 112]. An innovative hybrid FD method based on manifold learning and the isolation forest was established to diagnosis the condition of marine diesel engines [113]. ICA, short-time Fourier transform, PCA, and Fuzzy neural network (FNN) are fused as a new development method to realize marine diesel engines condition monitoring and FD [114].
The Enhanced Mechanism of 0.05 wt. % Nd Addition on High Temperature Reliability of Sn-3.8 Ag-0.7 Cu/Cu Solder Joint  
[PERSON]  
1 School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China; [EMAIL_ADDRESS]  
2 State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China; [EMAIL_ADDRESS]  
3 State Key Laboratory of Advanced Brazing Filler Metals and Technology, China Innovation Academy of Intelligent Equipment Co., Ltd., Ningbo 315700, China; [EMAIL_ADDRESS] (W.L.); [EMAIL_ADDRESS] (S.Z.)  
Correspondence: [EMAIL_ADDRESS]  
[PERSON]  
1 School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China; [EMAIL_ADDRESS]  
2 State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China; [EMAIL_ADDRESS]  
1 State Key Laboratory of Advanced Brazing Filler Metals and Technology, China Innovation Academy of Intelligent Equipment Co., Ltd., Ningbo 315700, China; [EMAIL_ADDRESS] (W.L.); [EMAIL_ADDRESS] (S.Z.)  
Correspondence: [EMAIL_ADDRESS]  
[PERSON]  
2 State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China; [EMAIL_ADDRESS]  
[PERSON]  
It has been reported that the RE elements with high chemical activity could have beneficial impacts on refining the microstructure of solder as well as inhibiting the growth of interfacial IMCs [13; 14]. [PERSON] et al. [15] added trace amount of RE La into Sn-Ag-Cu alloy and investigated its high-temperature reliability (150 \({}^{\circ}\)C). The results showed that the tensile strength of La-doped solder joint was 20 % higher than the pure one. In addition, La-doped solder witnessed the size of IMCs decreased by 40 %, and the coarsening rate of IMCs was slowed by 70% compared with the origin Sn-Ag-Cu solder. [PERSON] et al. [16] found that adding trace addition of Nd into SAC387 could hinder the growth of IMCs but excess addition of Nd may have unfavorable effects on the mechanical properties of as-soldered joint.  
In this study, the effect of appropriate Nd addition on long term high temperature reliability of Sn-3.8 Ag-0.7 Cu solder joint was investigated. The mechanical property and interfacial microstructure of solder joint after long term aging treatment was obtained. In addition, the effect of Nd addition on growth kinetics of interfacial IMCs during aging was evaluated.
# A Noise-Tolerant Carrier Phase Recovery Method for Inter-Satellite Coherent Optical Communications
## 6 Conclusions  
A novel low-complexity noise-tolerant carrier estimation method is proposed for inter-satellite coherent optical communications. The performance of the proposed method, as measured by the LRMSE\({}_{\theta}\), demonstrates a closer alignment with the MCRLB compared to traditional Diff-4 th methods, particularly in scenarios where \(E_{b}/N_{0}<5.2\) dB. This method exhibits enhanced estimation continuity and effectively mitigates the phase cycle slips that are typically encountered by the Diff-4 th methods. In addition, the noise-tolerant method shows improved BER performance. Specifically, at \(E_{b}/N_{0}\leq 4.5\) dB, the BER of the noise-tolerant approach is less than one-tenth that of the Diff-4 th method employing QPSK modulation. Furthermore, the noise-tolerant method achieves a reduction of 64% in the number of multiplications required. This advancement has the potential to decrease the demand for spaceborne computing resources while simultaneously enhancing the transmission reliability. The experimental results further validate the superiority and reliability of the proposed method within coherent optical communication systems. The fusion method demonstrates a superior ability to manage low-SNR channel conditions. By leveraging both feedback and feedforward mechanisms, the phase estimation can be rapidly adjusted, ensuring the stability and reliability of the communication link. Additionally, the proposed method is capable of consistently tracking the Doppler frequency shift induced by the relative motion between satellites.  
Formal analysis, C.H., Y.L., Z.W. and R.Y.; funding acquisition, X.B.; software, C.H. (MATLAB, version R2024a); experiment, C.H., Z.W. and R.Y.; writing--original draft, C.H.; writing--review and editing, C.H. and Y.L. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the National Key R&D Program of China (2023 YFF0717400).  
All data underlying the results are available as part of the article, and no additional source data are required.  
The authors declare no conflicts of interest.