esa-sceva/satcom-chunk-collection huggingface dataset:
## 5 Conclusions and Future Research Direction  
### Conclusions  
This article systematically reviews the research progress of precision rotary motion mechanisms and their driving technologies, revealing the core differences in performance, efficiency, and applicable scenarios between traditional mechanisms and new designs. Traditional gear mechanisms dominate industrial transmissions due to their high efficiency and structural stability. However, vibration noise and tooth surface wear issues under high dynamic conditions, such as contact stress concentration in spur gears and nonorthogonal shaft friction losses in worm gear transmissions, remain key bottlenecks. Traditional mechanisms have improved load capacity and service life through tooth profile correction of multi-tooth meshing, such as HCR gears, and surface treatment material strengthening, such as hardened worm gears. However, due to the fatigue limit and manufacturing accuracy of metal materials, it isn't easy to meet the requirements of ultra-high speed or extreme environments.  
The new mechanism has achieved performance breakthroughs through asymmetric topology design and multi-physics field coupling. The noncircular gear planetary system, combined with the gear ratio characteristics defined by the Fourier series, exhibits unique advantages in dynamic variable speed scenarios. However, the local wear caused by uneven stress distribution on the tooth surface must be optimised. Magnetic gears utilise the ideal diamagnetism of high temperature superconductors to achieve non-contact transmission, with torque density up to 1.73 times that of traditional structures; however, low temperature cooling systems' high cost and complexity limit industrial applications. The intermittent indexing mechanism improves the indexing frequency and motion stability through the cam connecting rod collaborative design. However, the accumulation of assembly errors and dynamic impact suppression in complex structures still needs to be solved through real-time damping control algorithms.  
The diversified driving technology development provides a new path for optimising institutional performance. In the electric drive system, the hollow cup motor eliminates the cogging effect through a coreless structure, but its dual rotor magnetic circuit design requires strict uniformity of the air gap magnetic field; Piezoelectric driving utilises the inverse piezoelectric effect to achieve micro nano motion control, but the hysteresis nonlinearity and preload relaxation problems under high-frequency excitation urgently require material control collaborative optimisation. Hydraulic and pneumatic drives perform outstandingly in high load and flexible scenarios, respectively. Still, the energy loss of hydraulic systems and the accuracy fluctuations of pneumatic transmission need to be balanced through a hybrid drive strategy.  
By analysing the impact of different driving methods on the performance of cam mechanisms through case studies, the comparative analysis results also apply to other precision rotary motion systems, providing engineers and researchers in various fields with more intuitive selection guidance.
## 5 Security Analysis
### Formal Security Proof
#### 5.1.1 Basics for Security Proof  
The security of \(\mathcal{P}\) was assessed based on the BPR2000 [32] and Bresson [33] solutions, also drawing inspiration from the proof techniques of [PERSON] et al. [24]. We detail these fundamentals as follows:  
Participants. The proposed \(\mathcal{P}\) involves two participants: \(U\) and \(S\). Each participant has multiple instances called oracles. The \(i\)th instance of \(U\) and the \(j\)th instance of \(S\) are denoted as \(U^{i}\) and \(S^{j}\), respectively. If no distinction is needed, any instance can be represented as \(I\).  
Queries. In a simulated attack scenario, the interaction between participants and adversary \(\mathcal{A}\) occurs solely through oracle queries. \(\mathcal{A}\) can perform the following types of queries:  
* Execute \(\left(U^{i},S^{j}\right)\): This query simulates the act of eavesdropping on the protocol, capturing all communication records exchanged between \(U^{i}\) and \(S^{j}\) as part of its output.
* Send \(\left(I^{i},m\right)\): This query simulates active attacks by intercepting and blocking a message; the adversary \(\mathcal{A}\) sends an imitative message \(mm\). \(\mathcal{A}\) then delivers \(mm\) to \(I^{i}\) and receives the response from \(I^{i}\).
* Reveal \(\left(I^{i}\right)\): This query discloses the session key to \(\mathcal{A}\). If \(I^{i}\) recognizes the session and generates an \(SK\), it returns the session key \(SK\) of \(I^{i}_{S}\) to \(\mathcal{A}\). Otherwise, it responds with \(\bot\), indicating no response.
* Corrupt \(\left(U^{i}\right)\): This query allows \(\mathcal{A}\) to acquire the secret data held by the user.
* Accepted state: Once an instance \(I\) receives and validates the final protocol message, it enters the accepted state. The ordered sequence of the exchanged messages up to  
Figure 3: Login and authentication phase.  
that point is then used to form the session identifier (session ID), for instance \(I\) in that particular session.
* Test (\(I^{i}\)): This query tests session key security. A coin \(b\) is flipped. If \(b=0\), a random key is sent to \(\mathcal{A}\). If \(b=1\), the actual \(SK\) is sent. If no \(SK\) exists for \(I^{i}\), \(\mathcal{A}\) gets \(\bot\). This query can only be used once.  
Partnering. Two instances \(U^{i}\) and \(S^{j}\) are partners if: (1) both are in the accepted state or (2) their session identifiers \((sid)\) match, i.e., \(sid_{U}^{i}=sid_{S}^{j}\).  
Freshness. An instance \(I\) is fresh if: (1) it has computed an accepted session key or (2) no reveal query about \(SK\) has been sent to \(\mathcal{A}\).
# Influence of Stray Current on Fastening System Components in Urban Railway Tracks
## 1 Introduction
If it occurs in the places where the rail is fastened to the concrete base using a discrete fastening system, the corrosion combined with the traffic load may lead to breakage of the rail foot and the elements of the fastening system [51]. In this case, the rail is no longer fastened to the base, and traffic safety may be compromised. According to [48], in most urban track systems the main task of the rail fastening system is to position and fasten the rails and transfer the vehicle load from the rails to the track substructure. The type and characteristics of the fastening system are selected depending on the required elasticity of the track, planned load, and rail type. The research carried  
Figure 1: (**a**) Paved tram track structure in Zagreb, Croatia, built as part of the road surface, as a discretely fastened track and its (**b**) cross section. out in this study shows that the type of fastening system also has an influence on the stray current and that the prevention of stray current must be one of the tasks that the fastening system must fulfill. This paper is divided into five sections. State-of-the-art methods are presented in the introduction (Section 1). Section 2 explains the motivation for conducting this study and research objectives. The materials and methods are described in Section 3. Section 3 also describes the test samples and the differences between them. The results are presented in Section 4. In Section 5, a tabular overview of the influence of stray currents on the observed test samples is provided, and the results of the research are summarized. Finally, Section 6 presents the main conclusions.
## 5 Experiment and Result Analysis
### Infrared Image Reconstruction Experiment  
We reconstructed low-resolution infrared images, thereby validating the effectiveness of our method in practical applications. We used 9 infrared images with a resolution of \(128\times 128\) taken on site for super-resolution reconstruction. The reconstruction results of image No. 9 using different methods are shown in Figure 5.  
According to Figure 5, the reconstruction result of the method proposed by [PERSON] et al. are the most ambiguous. The image details and textures reconstructed by the methods proposed by [PERSON] and [PERSON] are similar. Although they have a significant improvement in visual quality compared to the original low-resolution blurred images, they are still blurry. The method proposed by [PERSON] et al. reconstructed some significant textures of the image, but the textures have obvious defects. In addition, the image reconstructed by [PERSON] et al. has poor visual quality, due to the ringing effect, but the AG indexes of the image are relatively high. However, the images reconstructed by our method are the sharpest. In summary, our method has certain advantages over current methods in handling blurred LR images. In addition, the blur kernel estimated by our method in the reconstruction process allows us to discover that image blur is very complex. It is inaccurate to use the standard Gaussian blur kernel to represent the image blurring process; that is to say, it is necessary to study the blind SR algorithm. The SR reconstruction results of the other eight infrared images by different methods are listed in Tables 1 and 2 in the form of AG and IE metrics, respectively. It can be seen from the data in the tables that the reconstruction results of our method have certain advantages over these two indicators.  
Figure 5: Different methods to reconstruct the real infrared image of No. 9. (**a**) Real infrared image (**b**) Reconstruction results using the method in [30] (AG = 20.705, IE = 6.222) (**c**) Reconstruction results using the method in [19] (AG = 28.421, IE = 6.323) (**d**) Reconstruction results using the method in [11] (AG = 28.452, IE = 6.362) (**e**) Reconstruction results using the method in [21] (AG = 31.559, IE = 6.429) (**f**) Reconstruction results using our method (AG = 30.784, IE = 6.542).
# Driver Fatigue Detection Based on Residual Channel Attention Network and Head Pose Estimation
## 3 Materials and Methods
### Head Pose Estimation
\right] \tag{9}\]  
where \(\left[x_{j}^{c},y_{j}^{c},z_{j}^{c}\right]^{T}\) represents \(c_{i}^{c}\) and \(u_{i}\) and \(v_{i}\) represent the 2D point of face landmark. \(f_{u}\) and \(f_{v}\) are the focal lengths of camera. \(u\) and \(v\) are the optical centers of the camera. Continue to simplify Equation (10) to generate a linear equation by concatenating all the unknowns. \[M\left[c_{1}^{c^{T}},c_{2}^{c^{T}},c_{3}^{c^{T}},c_{4}^{c^{T}}\right]^{T}=0, \text{where}\left[c_{1}^{c^{T}},c_{2}^{c^{T}},c_{3}^{c^{T}},c_{4}^{c^{T}} \right]^{T}\text{is }12\ \times\ 1 \tag{10}\]  
The 3D coordinate values of the control points in the camera coordinate system can be obtained by solving Equation (11). The specific solution process is described in [21] and is not the focus of this article. The position and orientation of the camera can be calculated by getting all the control points. According to Equation (4), in this study, the 3D coordinates of five 2D landmarks in the camera coordinate system can be calculated. Next, the rotation matrix of the camera is calculated by the following steps:  
1. Calculate the centroid of 3D points (\(c_{0}^{v}\)) in the world coordinate system and the centroid of 3D points (\(c_{0}^{c}\)) in the camera coordinate system. 2. Set matrix \(A\) and matrix \(B\) and calculate them. The equation is as follows:  
\[A= \begin{bmatrix}P_{1}^{u^{T}}c_{0}^{u^{T}}\\ P_{1}^{v^{T}}c_{0}^{u^{T}}\end{bmatrix} ,B= \begin{bmatrix}P_{1}^{v^{T}}c_{0}^{v^ {T}}\\ P_{5}^{v^{T}}c_{0}^{v^{T}}\end{bmatrix}  \tag{11}\]  
3. Set matrix \(H\), which is decomposed by SVD. The equation is as follows:  
\[H=B^{T}A=U\sum V^{T} \tag{12}\]  
4. Calculate rotation matrix \(R\). The equation is as follows:  
\[R=UV^{T}=\left[ \begin{array}{ccc}f_{u}&0&u\\ 0&f_{v}&v\\ 0&0&1\end{array} \right] \tag{13}\]  
Finally, the head pose can be obtained by transforming the rotation matrix into the Euler angle. The equations are as follows:  
\[\theta_{x}=\arctan(r_{32},r_{33}).\theta_{y}=\arctan(-r_{31},\sqrt{r_{32}{}^ {2}+r_{33}{}^{2}}).\theta z=\arctan(r_{21},r_{11}) \tag{14}\]  
where \(\theta_{x}\), \(\theta_{y}\), and \(\theta_{z}\) represent the pitch, yaw, and roll of the head pose, respectively.
## 3 Results and Discussion
### SEM Analysis
#### 3.2.1 Ignimbrite  
SEM micrographs of the precursor material (ignimbrite), which was previously milled and passed through a 200 \(\upmu\)m mesh, are shown in Figure 2a. The figure reveals agglomerated particles with a varied morphology, suggesting a particle size below 100 \(\upmu\)m, which was consistent with the expected milling size. The EDS chemical composition analysis is shown in Figure 2c. In this sample, large amounts of silicon, aluminum, and oxygen were revealed, demonstrating the siliceous nature of ignimbrite, which favors zeolite synthesis. The spectrum also shows signals related to CaO and Fe\({}_{2}\)O\({}_{3}\), which could negatively affect the synthesis process [46].
# Biofilm Formation as a Complex Result of Virulence and Adaptive Responses of _Helicobacter pylori_
## 3 Transcriptomic and Proteomic Analysis of Biofilm _H. pylori_ Forms
pylori_ regulators during the transition to the biofilm phase, including Hsp, HrcA, CrdR, and RsfS, was also demonstrated by the team of [PERSON] et al. [21; 22]. Hsp and HrcA have a positive effect on the production of flagella and selected adhesions, while negative on the chaperone proteins (GroES, GroEL, and DnaK) [66; 67]. CrdR responds in _H. pylori_ to the nitrosic stress (exposure to NO) [49]. It was experimentally found that flagellar components, iron transporter (_fecA_, HP0807) and efflux pump (_glnP_, HP1169) were among the genes with the highest induction controlled by CrdR [49]. For RsfS, participation in the inhibition of large and small subunits of ribosomes has been shown and, as a consequence, a reduction of protein synthesis (one of the most energy-consuming physiological processes) [68]. This mechanism seems to explain the observations of [PERSON] et al., who noticed a decrease in the expression of translation genes during the transition of _H. pylori_ to the biofilm phase [21; 22]. Apart from global regulators having a positive effect on the production of biofilm, it is also worth paying attention to the existence of the ArsRS regulator, which is a two-component system negatively associated with the production of this structure [41; 52]. For ArsRS, the pH-dependent effect is indicated, during which exposure to the acidic pH of gastric juice inhibits the expression of genes related to biofilm formation, while in an environment with a neutral pH the effect of this system is inhibited [41]. The _\(\Delta\)arsS_ mutants showed a higher degree of adhesion to the surface and more intensive biofilm production (twice after 1-2 days and four times after 3 days of incubation than the wild-type strain) [41; 52]. Moreover, in these mutants, an increase in the expression of genes encoding outer membrane proteins was noticed; these included _alpB_ (omp21/_homB_), _sabA_ (omp17/_lopP_), _labA_ (omp2/_lopD_), and _hopZ_ (omp1) [52; 69]. The presented data show that global regulators can significantly influence the physiology of _H. pylori_ and determine the transition from planktonic to biofilm form and vice versa.
## 2 Materials and Methods
### A Case Study with Real Data: Prediction of Type 2 Diabetes Onset  
Besides the assessment with simulated data, the proposed algorithm was tested on a case study with real data, focused on the prediction of T2D onset.  
T2D commonly appears in people over 45 because of a combination of genetic and lifestyle factors. The major risk factor for T2D onset is obesity [29]. An early prediction of T2D onset is important because early interventions on modifiable risk factors can postpone or even prevent the incidence of the disease [20; 21]. Predictive models of T2D onset can help in identifying the high-risk subjects who may benefit from targeted prevention measures. Many literature studies focused on the development of a predictive model of T2D onset [3; 22]. Some of them also performed variable ranking in order to identify the most important predictors of T2D onset and perform feature selection [30]. The Cox model is one of the most popular techniques for building predictive models of T2D onset, as well as the onset of other chronic diseases [30; 31; 32].  
The aim of this case study is to use the Cox model combined with the variable ranking approach presented in Section 2.1 for ranking risk factors of T2D onset and building a predictive model of T2D onset that takes into account the most important factors. The study is conducted using the data collected in the English Longitudinal Study of Ageing (ELSA).
## 5 Discussion
### Variation in Sensor Lift-Off and Insulation Thicknesses  
As the interference caused by the sensor lift-off could be easily masked as a defect signal. To improve the thickness assessment accuracy, the feature change with the lift-off variation is investigated. Figure 9a shows Euclidean distances obtained with 5 mm, 10 mm, and 15 mm sensor lift-offs. The Euclidean distances under different lift-offs are basically overlapped. Therefore, the Euclidean distance is independent of the sensor lift-off.  
In addition, insulation thickness variations caused by installation irregularities or external forces could also affect the thickness assessment accuracy. Thus, the influence of insulation thicknesses on the Euclidean distances is examined. Figure 9b shows the Euclidean distance under different insulation thicknesses. The curves obtained with 40 mm, 60 mm, and 80 mm thick insulation are approximately overlapped, which indicates that the Euclidean distance is also independent of insulation thickness.  
In conclusion, the similarity measurement based feature is independent of the sensor lift-off and the insulation thickness.  
Figure 8: Variations of Euclidean distances due to different GS cladding thicknesses.  
Figure 7: Euclidean distances obtained with and without the SS cladding.
## 2 EO Satellite and In Situ Observations for Earth Surface
### LANDSAT and Its Legacy  
The Landsat program initiated with the launch of the first satellite in July 1972 and the latest Landsat-8 launched in February 2013 is the longest-serving EO platform of high resolution mapping satellites. Landsat-9 foreseen to launch in 2020 will continue this legacy that has allowed to monitor key surface changes over time, including water-bodies changes, glaciers retreat, large fires, urbanization and agricultural land expansions. Landsat 8 ensures the continued acquisition and availability of Landsat data utilizing a two-sensor payload, Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS). These provide imagery from 15 m to 100 m resolution and up to 700 scenes per day. Landsat data volume is prohibitive for most research applications at global scale and often used in mapping applications to produce more accurate medium resolution (e.g., at 1 km) as mentioned in Section 4.
# A Novel Hybrid Elementary Cellular Automata and Its Application in a Stream Cipher
###### Abstract  
The elementary cellular automata (ECAs) under the chaotic rule possess long periodicity and are widely used in pseudo-random number generators. However, their period is limited, related to the rule and the number of cells. Meanwhile, the Boolean functions of some ECAs are linear and vulnerable to linear analysis. Thus, the ECA cannot be directly implemented in the stream cipher. In this paper, a hybrid ECA (HECA) with dynamic mask (HECA-M) is designed. The HECA-M consists of two parts: the driving and mask parts. The driving part based on a HECA is used in generating the keystream, and the mask part based on a chaotic ECA is utilized to determine the iterative rule of the driving part. Subsequently, a stream cipher based on the HECA-M and SHA-512 is proposed. The statistic and secure analyses indicate that the proposed stream cipher possesses good randomness and can resist stream cipher analyses, such as exhaustive search, Berlekamp-Massey synthesis, guess and determine attack, time-memory-data tradeoff attack, etc. Hence, the proposed scheme can meet security requirements. Moreover, the time and space consumption of the proposed stream cipher is qualified.  
stream cipher; elementary cellular automata; dynamic mask; hybrid; chaotic
# Reconstruction of Preclinical PET Images via Chebyshev Polynomial Approximation of the Sinogram
## 6 Conclusions  
In the present study we have presented a new mathematical formulation for the analytical inversion of the Radon transform and its corresponding numerical implementation based on Chebyshev polynomials of the first kind. We have tested our algorithm on a simulated IQ phantom and compared our results with FBP, the industry-standard analytic reconstruction method in PET. For the evaluation of our simulated studies based on Chebyshev polynomials of the first kind, we employed the \"NEMA NU 4-2008 standards\" protocol. Our results indicate that our Chebyshev-based reconstruction technique is comparable with FBP, probably providing a good analytic alternative for two dimensional reconstructions. In future studies, we aim to investigate the performance of our analytic reconstruction algorithm in clinical PET studies, especially as it compares with FBP and ordered subsets expectation maximization (OSEM).  
**Author Contributions:** Conceptualization, N.E.P., A.S.F., V.M. and G.A.K.; methodology, N.E.P., V.M. and G.A.K.; software and validation, N.E.P., A.V., N.D. and G.A.K.; writing--original draft preparation, N.E.P.; writing--review and editing, N.E.P., A.S.F., A.V., V.M., N.D. and G.A.K.; visualization, N.E.P., A.V. and N.D.; supervision, G.A.K. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was partially supported by the research programme No. 200/948 of the Research Committee of the Academy of Athens.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.  
**Conflicts of Interest:** The authors declare no conflict of interest.
## 4 Discussion
### Impact of Retrieval Window  
Figure 11 presents the slope and goodness-of-fit (GOF) of the linear fit between the SIF retrieval results from the combined retrieval window (including O\({}_{2}\) absorption and FLs bands) and the FLs band alone with GPP/EVI. The fitting is performed on a monthly scale and at a 0.1\({}^{\circ}\) spatial resolution, encompassing the retrieval results for the entire year of 2019. The retrieval results from the combined window exhibit a slightly higher degree of dispersion compared to the linear fit results. Due to the lack of direct validation for SIF products, it is unclear whether this is caused by the introduction of a small amount of noise from the O\({}_{2}\) absorption bands or a true reflection of the SIF-GPP/EVI relationship. What is certain is that the inclusion of the O\({}_{2}\) absorption bands facilitates better decoupling of the SIF spectra from the singular vectors. As a result, the SIF products obtained from the combined retrieval window exhibit higher slopes relative to GPP/EVI, leading to a higher GOF.