esa-sceva/satcom-chunk-collection huggingface dataset:
# A Novel Protocol Using Captive Portals for FIDO2 Network Authentication +
## 4 Fido2 cap: FIDO2 Captive-Portal Authentication Protocol
### Authentication Protocol  
Figure 3 shows the FIDO2 CAP authentication protocol message flow. The parts highlighted in blue are modified or added to the RFC [8]. The FIDO2 CAP protocol starts with the captivity signalling from the router. When the User Equipment requests the captivity status, the captive-portal API Server replies with the WAWA URI. This opens a web browser in the User Equipment, visiting the WAWA user interface. Here, the user sends the username for identification (this is the optional step with discoverable credentials, see Section 4.2.2).  
The username allows the WAWA application to search for registered FIDO2 Authenticators linked with the user in the User Database. With this information, the WAWA server generates the Allowed Credentials list, and the WebAuthn challenge, which is sent to the Web Browser. In the user end, the browser initiates the WebAut  
Figure 3: Authentication message flow in FIDO2 CAP. The User Equipment is connected to the captive portal, getting redirected to the WAWA server URI. The user performs FIDO2 authentication at the WAWA User Portal UI. After verifying the authentication, the Enforcement Device allows access to the User Equipment, ending captivity.  
with the authenticator via the OS CTAP GetCredentials call. After the user interacts with the authenticator via User Presence (UP) and/or User Verification (UV), the FIDO2 Authenticator signs the challenge and sends its response, which is forwarded to the WAWA server. Finally, the response is verified, and the WAWA server notifies the Enforcement Device, allowing the User Equipment to access the external resources, ending the captivity.
## 4 Experimental Results  
### Frames Encrypted per Sec (\(\text{FPS}_{\text{enc}}\)) Analysis  
Figure 3 presents the real-time video feed frames encrypted per second (\(\text{FPS}_{\text{enc}}\)) by the selected LWSCs. The results demonstrate that Salsa and Sosemanuk outperform the other ciphers, achieving the highest frame encryption rates. Grain-128a exhibits moderate performance. In contrast, Grain-v1, Mickey-v1, and Trivium have the lowest \(\text{FPS}_{\text{enc}}\), increasing in the aforementioned order.  
Figure 3: Frames encrypted per second by the selected Lightweight Stream Ciphers (LWSCs).
# A Geostationary Instrument Simulator for Aerosol Observing System Simulation Experiments
## 2 Methodology and Data
### TOA Radiance Simulations
#### 2.4.2 Forward Radiative Transfer Calculations with VLIDORT
Forward radiative transfer calculations were done for 5 channels in the UV-Vis, which span the TEMPO, GEMS, and SENTINEL-5 spectral domains and are currently used for aerosol retrievals: 354, 388, 470, and 550 nm. Additional calculations at 670 nm and 1.3 um were completed for TEMPO only. These data are freely available for download at [http://g5 nr.nccs.nasa.gov/data/OBS](http://g5 nr.nccs.nasa.gov/data/OBS). The radiative transfer calculations described in this paper are applicable throughout the UV-Vis, and additional datasets can be generated by request to the authors.
# A Wideband High-Voltage Power Amplifier Post-Linearizer for Medical Ultrasound Transducers
## 1 Introduction
However, the post-linearizer scheme was deemed to be more efficient because it can be physically connected to medical ultrasound transducers to enable direct control of the non-linear harmonic distortions generated by the transducers. Therefore, an HVPA incorporating a post-linearizer technique would facilitate the reduction of the harmonic effects of medical ultrasound transducers. To the best of our knowledge, this paper presents the first HVPA post-linearizer circuit technique for use in medical ultrasound transducers. The operating principles, design, and performance of the HVPA incorporating a post-linearizer will be described in this article. One of the biggest challenges in HVPA design is achieving wide bandwidth and high linearity simultaneously. This is due to the parasitic impedances from electronic components, such as the power transistor, inductor and capacitor; and non-linear ultrasound transducers, including cable-loading effects [7; 27]. Additionally, power transistor models are not accurately predictable at the circuit-design level [28; 29]. Because most linearization techniques have been developed in narrow-band frequency ranges, it is thus quite difficult to design a linear broadband HVPA for used in medical ultrasound transducers [28]. Figure 1 is a drawing of the typical characteristics of the HVPA with and without the linearizer in medical ultrasound systems. The gain deviation curve of the HVPA should be flat for a wide range of input powers and frequencies because the HVPA must linearly amplify the signals with low signal distortion even at higher input power and frequency ranges.
# A Complete Key Management Scheme for LoRaWAN v1.1 +
## 4 LoRaWAN v1.1 Security Structure Analysis
### Operational Stage
#### 4.2.3 Key Backup and Recovery  
This part is not discussed in the LoRaWAN v1.1. In the case of join sever accidentally deletes the end device root keys, it must have a backup server that can make the root keys recoverable. Session key backup and recovery are not an issue because the end device or the relevant servers can always ask the end device to re-join the network. However, the smoothness of the key backup and recovery is of concern since an improper transition may result in an unpleasant quality of service.
# Pro-Health Potential of Selected Uncommon Oilseed Plants
## 3 Pro-Health Potential of Selected Uncommon Oilseed Plants
### Nigella sativa L.
#### 3.3.4 Antidiabetic Properties  
Extensive research has been conducted on the antidiabetic properties of black cumin, yielding promising results in studies involving both human subjects and animal models. This issue remains of great interest and significance within the scientific community. Black cumin seeds, oil, and extracts are all utilized in research endeavors. An ethyl acetate fraction from _N. sativa_ ethanol extract, administered at a dose of 500 and 1000 mg/kg body weight, significantly reduced blood glucose levels in alloxan-induced diabetic rats. Furthermore, no pancreatic necrosis was observed in these rats, in contrast to the control group [100]. In a randomized, double-blind, controlled trial, it was demonstrated that the supplementation of 2 g/day of nigella oil led to significantly increased levels of superoxide dismutase and total antioxidant capacity, while malondialdehydedehyde, high-sensitivityC-reactive protein, glycosylated hemoglobin, and fasting blood sugar levels decreased significantly in diabetic patients undergoing hemodialysis. Notably, no significant changes in insulin levels were observed. These findings indicate that the use of nigella oil may serve as a valuable adjunct to the treatment of these patients, mitigating oxidative stress, inflammation, and blood sugar levels in diabetic individuals undergoing hemodialysis [82]. A double-blind, randomized, controlled clinical trial conducted by [PERSON] et al. [101] assessed the impact of daily administration of 500 mg of _Nigella sativa_ L. seed powder on blood sugar levels and lipid profiles in patients with type 2 diabetes. In the experimental group, there was a significant decrease in HbA1c (glycated hemoglobin) levels and total cholesterol levels, and a significant increase in high-density lipoprotein levels [101]. Reports of black cumin's antidiabetic effects prompted researchers to compare its effects to those of metformin. [PERSON]'s et al. [102] research was conducted to compare the efficacy of monotherapy with black cumin oil at a dosage of 1350 mg/day to metformin at a dosage of 2000 mg/day in patients newly diagnosed with type 2 diabetes. The findings indicated that while black cumin oil demonstrated lower effectiveness than metformin in managing type 2 diabetes, e.g., by reducing fasting glucose and glycated hemoglobin and increasing pancreatic secretory function, it showed comparable results in terms of reducing body weight, waist circumference, and BMI. Both black cumin oil and metformin therapies exhibited similar effects on fasting insulin levels, insulin sensitivity, insulin resistance, alanine aminotransferase (ALT), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG) levels, and total antioxidant capacity [102].
## 4 A Framework for Feature Curves on SPD Manifold
### Recognition between Families of Features Curves
Output: Predicted label \(l^{query}\) of \(V_{query}\) /* Compute DTW distances among sample and query feature curves */ for\(i\gets 1\) to \(m\) for\(j\gets 1\) to \(n\)do \(\Psi(i,j)=\delta_{\text{DTW}}\left(\Gamma_{R_{i}}^{query}(t),\Gamma_{R_{i}}^{ j}(t)\right)\) end for  end for /* Compute average DTW distance matrix \(\psi^{*}\)/ for\(k\gets 1\) to \(m\)do \(\psi(1,k)=\frac{1}{m}\sum\limits_{i=1}^{m}\Psi_{i,k}\) end for /* Testing phase */ \(l^{query}\leftarrow\) KNN classifier using average DTW distance matrix \(\psi\) Return Predicted label \(l^{query}\) of \(V_{query}\)
```  
**Algorithm 2** Classification of a Family of Feature Curves \(\left\{\left\{\Gamma_{R_{i}}^{j}(t)\right\}_{i=1}^{m}\right\}_{j=1}^{n}\) on SPD Manifold  
The other is the pre-classification strategy suitable for the number of ROIs \(m\) in the pattern being larger. Each feature curve of query video \(V_{query}\) is pre-classified independently according to each row of similarity measure matrix \(\Psi\). On the basis of the law of large numbers [38], the label with the highest frequency among \(\left\{l_{1}^{query},\cdots,l_{n}^{query}\right\}\) is regarded as the label of the query video \(V_{query}\). Taking the KNN classifier as an example, the steps of the pre-classification method are shown in Algorithm 3. ```
Input:\(n\) sample families of feature curves \(\left\{\left\{\left\{I_{R_{i}}^{j}(t)\right\}_{i=1}^{m},I_{j}^{V}\right\}_{j=1}^{n}\right.\) with their corresponding labels of each family, a family of feature curves \(\left\{I_{G}^{query}(t)\right\}_{i=1}^{m}\) of query video \(V_{query}\). Output: Predicted label \(l^{query}\) of query video \(V_{query}\) /\({}^{*}\) Compute distances among sample and query feature curves \({}^{*}\)/ for\(i\gets 1\) to \(m\) for\(j\gets 1\) to \(n\)do \(\Psi(i,j)=\delta_{DTW}\left(I_{R_{i}}^{query}(t),\Gamma_{R_{i}}^{j}(t)\right)\)  end end /\({}^{*}\) Testing phase \({}^{*}\)/ for\(k\gets 1\) to \(m\)do \(l^{query}_{k}\leftarrow\) KNN classifier using the \(k\)-th row of distance matrix \(\Psi\) end Return Mode of \(\left\{l^{query}_{1},\cdots,l^{query}_{m}\right\}\) as predicted label \(l^{query}\) of \(V_{query}\)
```  
**Algorithm 3** Classification of a Family of Feature Curves \(\left\{\left\{I_{R_{i}}^{j}(t)\right\}_{i=1}^{m}\right\}_{i=1}^{n}\) on SPD Manifold  
In summary, our proposed framework focuses on short video recognition. The few transitions of short videos help to trace the coherent trajectory of ROI with motion estimation. Moreover, stringing time series of ROIs extracts both spatial and temporal features from short video. Furthermore, modeling time series of ROIs as feature curves on the SPD manifold via RCDs introduces the Riemannian geometry. Finally, our framework provides different strategies for stringing time series of ROIs, constructing RCDs, and classifying between families of curves, improving the universality and stability of our framework.
## 4 Modulation Techniques for Underwater VLC
### Hybrid Modulation Techniques
\begin{tabular}{c} BER \(<10^{-5}\) in \\ moderate \\ turbulence \\ \end{tabular}  & [39; 40] \\ \hline
16-QAM & \begin{tabular}{c} Combines \\ amplitude and \\ phase modulation; \\ encodes 4 bits per symbol \\ \end{tabular}  & \begin{tabular}{c} Higher data rates, \\ efficient spectral \\ utilization \\ \end{tabular}  & \ \begin{tabular}{c} Increased noise \\ sensitivity \\ \end{tabular}  & \begin{tabular}{c} Suitable in \\ medium SNR; \\ high data \\ throughput \\ \end{tabular}  & [41; 42] \\ \hline  
Recent advances in hybrid modulation demonstrate significant improvements over standalone techniques. As shown in Table 3, our proposed adaptive QAM-OFDM scheme achieves 5 Gbps at 100 m with a BER of \(10^{-6}\) in coastal water, outperforming [32] QAM-OFDM (4.92 Gbps at 1.5 m) by 60% in distance under similar turbidity conditions. Compared to [35] PAM4 (500 Mbps at 150 m), our method reduces BER by 50% (\(10^{-6}\) vs. \(10^{-4}\)) while maintaining a comparable range. Notably, [44] hybrid QPSK-APSK (3.18 Gbps at 56 m) exhibits higher nonlinearity tolerance but falls short in data rate (30% lower than our scheme). These gains stem from dynamic bit-loading and RIS-assisted signal recovery, mitigating turbulence effects that limit [36] SiPM-based system (2 Gbps at 55 m). Such improvements position our approach as a viable solution for high-speed UVLC in challenging environments.
## 4 Experiment
### Experiment Setup  
To verify the effectiveness of the proposed control scheme in this paper, two teleoperation schemes C1 and C2 were compared in two designed situation sets, Set1 and Set2. More concretely, a relatively new control method presented in [36] is experimentally compared, where all the experimental conditions and common parameters are the same to have a fair comparison. The different two control schemes are described as follows:  
C1. The original wave variable-based control design reducing reflections proposed by in [36], where \(b=10\) and the constant time delay is set as \(T=0.2\). In addition, the parameters of PID controller are selected as \(K_{P}=5\), \(K_{I}=2\), \(K_{D}=0.05\) to achieve rapid and stable response of each actuator.  
C2. The modified wave variable-based control scheme proposed in this paper to guarantee the position-tracking performance and improve the transparency of force feedback, where \(b\), \(T\) and PID controller remain the same with C1 and the secondary parameter \(K\) is selected as a small value with \(K=0.5\). Moreover, considering the frequency of desired trajectory, the parameter of low-pass filter is set as \(\lambda=20\).  
As illustrated by Equation (23), to provide operators with the perception of tracking errors and constrained location, a virtual force feedback is generated during the whole moving phase. Thus, two different situation sets are designed to show the transparency performance of the proposed control scheme in free or constrained motion space as follows:  
Set1. The experiments into trajectory tracking in free motion space are carried out to show the accurate kinematics control of CHCM and the improvement of force feedback transparency adopting control scheme C2. During free motion, the parameter of force feedback \(k_{f}\) is set as \(k_{f}=3\).  
Set2. The experiments into trajectory tracking when reaching and released from the constrained space are carried out to show the rapid change of virtual force feedback with guaranteed tracking performance, which could reflect the influence of constrained space. The spring modulus and damping coefficient of the environment are set as \(k_{b}=0.5\), and \(c_{b}=1\) respectively when CHCM reaches the setting boundary.
## 3 Results and Discussion
### NO Formation Characteristics of NH\({}_{3}\)/CH\({}_{4}\) Combustion
#### 3.2.3 Effect of Temperature \(T\) on NO Production  
This section details the effects of different combustion temperatures on the amount of NO produced by NH\({}_{3}\)/CH\({}_{4}\) combustion under different excess air coefficients. The experimental results are shown in Figure 5. As was determined in Section 3.2.1 that when ammonia accounted for about 40% of mixed fired gas, NO emissions reached the maximum value. Therefore, we used 40% ammonia in mixed fuel gas for the experiment and the combustion temperatures were 900 \({}^{\circ}\)C, 1100 \({}^{\circ}\)C, 1300 \({}^{\circ}\)C, and 1500 \({}^{\circ}\)C. Excess air coefficients were 0.9, 1.0, and 1.1.  
As shown in Figure 5, under the three excess air coefficients, NO emission decreased with the increase in temperature, and the decline rate of NO emission slowed down with the gradual increase in temperature. Within a certain temperature range, NH\({}_{3}\) can enhance the reduction of NO\({}_{\mathrm{x}}\) through the thermal denitration process, and Reactions (6) and (8) occur.  
At the end of Reaction (8), NO is reduced to nitrogen, and the increase in temperature reinforces this step, leading to a decrease in NO production with increasing temperature.  
Figure 5: The content of NO in combustion flue gas at different temperatures.  
With the increase in temperature, the branching ratio gradually increases, resulting in the increase in NNH production, then resulting in the following processes:  
\[\text{NNH}=\text{N}_{2}+\text{H} \tag{15}\]  
\[\text{H}+\text{O}_{2}=\text{O}+\text{OH} \tag{16}\]  
\[\text{O}+\text{H}_{2}\text{O}=\text{OH}+\text{OH} \tag{17}\]  
Since NNH is short-lived, the amino group will react with the O/H radical to form NO. Reactions of (6) and (8) are gradually balanced, so that the decline rate of NO production gradually slows down.
# Remote Sensing for International Peace and Security: Its Role and Implications
## 5 Future Perspectives
### Technology Development Perspective
#### 5.1.3 Internet of Things (IoT) Based Survey  
The emergence of distributed computing has revolutionized the world across various domains. The use of the Internet of Things (IoT) in remote sensing applications for international peace and security is gaining popularity, enabled by the facility of cost-effective and reliable network services. The mitigation strategies, challenges, and risks of using IoT-based remote sensing for international peace and security have been disheveled [122].
## 2 The Control Problem for the Prototype UH Stability Augmentation System
### Remarks  
**i.** The direct addition of an external feedback term like \(a\cdot q\) to \(\delta_{e}\) is necessary without any modification of the adaptive laws if \(M_{q}^{\dot{q}}\) cannot satisfy \(M_{q}^{\dot{q}}<0\) at a certain flight condition, where \(a\) is used to guarantee the stability of the plant, that is, \(M_{q}^{\dot{q}}+M_{\delta_{e}}^{\dot{q}}a<0\) in this case.  
**ii.** In consideration of the adverse effect of measurement noises, the variance of the noise component of \(\delta_{e}\) can be reduced while using the proposed adaptive algorithm, mainly because the model feedback path is noise free, which can result in the improvement in the control quality of the stability augmentation system, especially in the case of low signal to noise ratios (SNR).  
**iii.** Compared to the model reference adaptive control (MRAC) method, the additional time-varying parameter \(\kappa\) in the proposed algorithm can contribute to the convergence rates of adjustable parameters when the plant parameters vary rapidly.
###### Abstract  
In view of the problems of rapid construction and deformation control of large cross-section tunnels in complex urban environments, the concept of \"timely high-strength support\" was put forward to form strong support over time and bear the load of surrounding rock in real time, and innovatively developed the spatial reticulated grid bolt-shotcrete support structure (SRGB). The research in this paper focuses on the supporting principle, bearing mechanical properties, snatch simulation test, construction process, and engineering application effects. The components of the SRGB and their respective functions were expounded in detail. The failure modes and deformation characteristics of the tested components were revealed through the indoor loading test, and the performance characteristics of the spatial reticulated grid concrete components with high strength and high rigidity were displayed. With the help of the multi-functional operation trolley, the assembly process test of the spatial reticulated grid was carried out, which verified the feasibility of mechanized construction and the rationality of structural design. Relying on the underground tunnel project of Guangzhou Metro, the spatial reticulated grid structure was successfully used as the initial support of the tunnel for the first time, forming a complete set of mechanized rapid construction technology for a large cross-section tunnel, and constructing a timely high-strength support system suitable for the complex urban environment. The research results provide a new idea and new technology for the mechanized rapid construction and efficient support of large cross-section tunnels.  
excavation tunnel; spatial reticulated grid; bolt-shotcrete support; model test; bearing performance; mechanization; field test +
Footnote †: journal: Applied Sciences
# A Symmetric Matrix-Aided MIMO to Improve Reliability for Maritime Visible Light Communications
## 3 Symmetric Matrix-Aided MIMO-VLC System  
In this section, we will introduce the MIMO-VLC system and propose the symmetric matrix design. Then theoretical performance analysis is also provided.
## 3 Results and Discussion
### Protein Oxidation  
The loss of SH groups, which is a consequence of disulfide formation, has been often used as the marker of protein oxidation [29; 38; 43]. Based on the results, it could be stated that both, time and the treatments affected significantly the content of SH groups (Figure 4). The loss of SH groups increased in all raw chicken samples when storage proceeded. The lowest content of SH was observed for the control sample (from 36.8 to 21.4 nmol/mg). The addition of extracts increased oxidative stability of proteins in raw chicken legs. The inhibition of disulfide formation was the most pronounced in the samples containing cloves and allspice (mean SH content during storage was 52.2 nmol/mg and 51.6 nmol/mg, respectively). Black seed was also very effective antioxidative treatment (47.4 nmol/mg). The samples could be ranged in the following order of increasing SH group content: Control! nutmeg! cardamom! caraway! bay leaf! black seed! allspice! cloves. Increased oxidative stability of proteins after addition of plant extracts was reported in chicken nuggets stored at -18 \({}^{\circ}\)C containing grape seed extract [43], and in raw pork patties with persimmon peel extract [38]. Whereas, in chicken sausages with hydroxytyrosol extract the SH content was lower than in the control sample, which was probably due to protein-phenol interactions [29].  
Figure 3: Effect of various spice extract treatments on the oxidation induction period (IP) determined by DSC. Means with the various superscript within the same day are significantly different (\(p\leq\) 0.05, Duncan’s test). Vertical bars indicate 0.95 confidence intervals.