esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Structural Characteristics and Dynamic Behaviors of Cylinder Liners
### Meshing and Boundary Conditions  
To improve the computational efficiency, some geometric details on the outer surface of the cylinder liner were neglected. The model of cylinder liner was configured to have 7121 hexahedral isoparametric solid elements using ANSYS Workbench, while the other components were treated as rigid body in modeling to reduce the need for solution time and computing sources, as shown in Figure 2b. Because of the large number of simulation steps in the transient dynamics analysis, about 1000 steps for each case, both the larger number of grids and smaller mesh size can result in a dramatic increase in the need for solution time and computing sources. Specifically, when the grid size is chosen to be 2.5 mm, half the thickness of the liner, the solution time of a whole operating cycle is 5.8 times the grid size of 5 mm, while the amplitude error of the two simulated displacement is less than 2%. For the balance between acceptable accuracy and computing efficiency, hexahedral elements with a grid size of 5 mm are adopted for three-dimensional meshes. Arranging the mesh with finer elements in this way allows for vibration analysis at frequencies up to 10 kHz, which was estimated based on analytical analysis when the liner is assumed to be a uniform cylindrical shell [14]. Even so, the solution time of a whole operating cycle takes up to seven hours. The material for the liner in this research is ductile cast iron QT600-3 [15]; material parameters appear in Table 1.  
Figure 1: Construction of wet cylinder liner.  
Boundary conditions of the studied cylinder liner are shown in Figure 2a where the liner is a non-uniform cylinder-shaped shell with end-flanges. To avoid altering the liner's modal characteristics caused by improper boundary condition definition, the fixed joints and clearance fits have been modelled through constructing a series of frictionless CONTACT pairs as seen in Figure 2b, which effectively avoids the errors induced by over-simplification and inappropriate structural equivalent in the modelling of the cylinder dynamics [14]. In this way, it allows taking into account more successfully the slight changes in modal characteristics of the cylinder liner, leading to more accurate analysis.  
In addition, to handle the nonlinearities arisen from the contact constraints, a reduced method from the Newmark implicit integration method was chosen to solve the motion equations. The method has acceptable accuracy in solving the nonlinear model. In the meantime, it has better computing efficiency.
# Distributed Rateless Codes with Unequal Error Protection Property for Space Information Networks
## 1 Introduction
Furthermore, there are several scenarios where the conventional rateless codes cannot perform optimally due to the lack of unequal error protection (UEP). For example, when transmitting the data blocks of discrete wavelet-transform encoded images in SIN, the lower frequency part of data blocks are more important than the higher frequency parts. Thus, it is more desirable to use rateless codes with UEP to protect the important parts. The first scheme of rateless codes with UEP property is proposed in [21], and message symbols are allocated two different weights according to their importance levels. In [22], expanding window fountain codes is proposed to generate output symbols only from message symbols within a certain window. Two overlapping and expanding windows are pre-designed, such that the smaller window contains important message symbols, and the larger window contains all the symbols. A distributed rateless code with an unequal error protection (UEP) property has been proposed in [23] for a Y-network, and it can provide different data importance levels with different error probabilities for two sources. The generalized UEP rateless code (GURC) for distributed relay networks is proposed in [24], and the relationship between UEP property and decoding error rate (DER) of LT codes is obtained by the And-Or tree analysis [25]. However, the UEP property for multiple source nodes and original data in a dynamic network topology of SIN is still lacking research. Considering a relay has its own orbit around the mission planet, which makes the links between landed rovers and the relay being periodically available. Since the space explorers have limited energy, broadcasting is prohibited. Thus, the rovers cannot communicate with the relay and destination simultaneously. In this paper, to improve the throughput of the multimedia service in future SIN communications, we proposed a novel distributed UEP rateless coding (DURC) scheme for the multimedia data transmission in a multi-access relaying SIN, which could obtain a lower DER under the pre-selected parameters of UEP property. Specifically, the RC degree distributions and network coding rules are designed to match the duration of the link access conditions. The rest of the paper is organized as follows. In Section 2, we present the system model and our DURC scheme. In Section 3, we derive the asymptomatic performance based on the And-Or tree analysis and optimize the degree distributions and network coding rules by using multi-objective programming. In Section 4, we employ NSGA-II to design DURC codes and evaluate the performance of the DURC under different channel conditions. Finally, we conclude the paper in Section 5.
## 2 Materials and Methods
### Relative Feature Importance  
Relative feature importance measures the contribution of each feature to the performance of a machine learning model. It highlights which variables have the greatest impact on the model's predictions, allowing for better understanding and interpretation of the results. In land use and land cover (LULC) classification, feature importance can reveal which spectral bands, indices, or temporal characteristics are most influential in distinguishing between different classes. This insight helps refine models, optimize data inputs, and prioritize variables for future analyses. In our study, the analysis of relative feature importance focused on the spectral bands of Sentinel-2 across three seasons: spring, summer, and autumn. A total of 36 features were analyzed, corresponding to the 12 spectral bands for each season: B1_spring through B12_spring, B1_summer through B12_summer, and B1_autumn through B12_autumn. This approach allowed us to assess the seasonal contributions of individual bands to the classification process and understand their relative significance in distinguishing land use and land cover types.
## 1 Introduction
Therefore, the haptic rendering of the overall forces in the SPRINT platform was not based on the actual kinematic and dynamic features of a rowing movement. In our laboratory, we also developed a rowing simulator to support realistic training for sculling and sweep rowing indoors [23]. Thanks to the real-time control and dedicated hardware setup, our rowing simulator has been used for training of rowers [22] and motor learning related research such as augmented feedback designs [24; 25] and robotic training strategies [26; 27]. The haptic rendering of the rowing forces incorporated the effect of the 3-DoF rotation of an actual rowing oar and of the boat dynamics [28]. The propulsion forces were calculated according to an empirical model [29], which approximated the drag and lift forces acting on the blade [21]. Although the model was previously shown to be suitable for technique training [22], expert rowers suggested that the realism of the rendered resistive forces on the simulator could be improved. Therefore, in this study, we proposed a new three-dimensional force model that incorporates 3-DoF rotation of the oar and accounts for a smooth blade transition between air and water. The new force model was implemented on our rowing simulator and assessed by ten expert rowers in a training experiment. In the first part of the experiment, rowers were asked to qualitatively assess both the existing oar-blade model [21] and the new model. We hypothesized that the new blade force model would be perceived as more realistic than the existing model. In the second part of the experiment, the benefit of individualizing the force model on expert rowers' acceptance of the rowing simulator as a training platform was investigated. We hypothesized that the individualization of model parameters would result in higher realism of perceived rowing forces of the simulator.
# Experimental Study of Interfacial Bond Properties between CGM and Existing Concrete
## 1 Introduction
Moreover, as far as we know, no literature on the interfacial bond-slip model (which is helpful for fine finite element simulation analysis) of normal concrete reinforced with CGM has been published. The bond performance at the interface is the key to ensuring the bearing capacity of reinforced or prefabricated structures. Thus, conducting in-depth and systematic research on the bond performance of CGM and existing concrete is necessary. Interfacial shear performance is an important index to evaluate interfacial bond performance, especially for areas with high shear stress where the possibility of shear failure is high. Interface shear resistance can be evaluated through direct [13] and slant [14] shear tests. The commercial CGM-I type grouting material suitable for repair and reinforcement engineering was used as the reinforcement material in this study. By considering the influencing factors, such as the existing concrete's strength, interface form, shear key setting, and shear angle, direct and slant shear specimens were designed and prepared from the perspective of engineering practicality. Loading tests were performed to systematically analyze the factors that affect the bond between CGM and concrete. A bond-slip model of the interface between CGM and existing concrete was proposed. The experimental data in this study can be beneficial for reasonably optimizing the structural design of the bond interface and improving the bearing capacity of reinforced structures. This study also provides a scientific basis for using CGM as a bonding material to connect assembly components.
## 4 Conclusions  
To explore a new and effective method for maritime communication across the Taiwan Strait, we presented a preliminary investigation of wireless microwave transmission in an evaporation duct. Based on the meteorological parameters drawn from NCAR datasets, the temporal characteristics of the EDH at a typical position (23.4\({}^{\circ}\) N, 120.0\({}^{\circ}\) E) of the Taiwan Strait during 2020 were analyzed with the theoretical method of the NPS model. Moreover, transmission in the ducting layer was further analyzed from the perspectives of propagation loss and communication effect.  
Affected by the TSWC, the evaporation around the Taiwan Strait is significantly higher than in any other area in the SCS [16]. Our model showed that, during 2020, the percentage of EDH exceeding 10 m reached over 90% from 9 to 14 o'clock. Using the favorable channel conditions in this period, a wide contour area with a path loss below 160.0 dB emerged, with a serviceable ratio of 99.00% at a 300 km transmission range. The high-quality transmission in BPSK modulation occurred for 98.90% of the year from 12 to 13 o'clock, with 89.89% of the SNR exceeding 90 dB. The preliminary investigation in this study may provide basic support for constructing a communication system using evaporation ducts across the Taiwan Strait.  
C.Y.: conceptualization (equal), data curation (equal), investigation (equal), methodology (equal), software (equal), validation (equal), visualization (equal), writing--original draft (equal); Y.S.: conceptualization (equal), data curation (equal), investigation (equal), methodology (equal), software (equal), validation (equal), visualization (equal), writing--original draft (equal); J.W.: conceptualization (equal), data curation (equal), investigation (equal), methodology (equal), software (equal), validation (equal), visualization (equal), writing--initial draft (supporting). All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China (No. 62031008) and the State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information Systems (No. CEMEE2022G0201, CEMEE-002-20220224).  
Not applicable.  
The reanalysis data could be obtained through the NCAR public website [[https://rda.ucar.edu/](https://rda.ucar.edu/)]([https://rda.ucar.edu/](https://rda.ucar.edu/)).  
The authors declare no conflict of interest.  
Figure 9: The SNR and BER of periods from 12 to 13 o’clock in the Taiwan Strait during 2020.
## 4 c-di-AMP Binding Molecules
### Histidine Kinase Protein, KdpD  
KdpD is yet another c-di-AMP binding protein identified from _S. aureus_, this time by screening a recombinant _S. aureus_ ORFeome expression library using DRaCALA [17]. KdpD is a histidine kinase that functions as a two-component system (TCS) with KdpE, the response regulator. Generally, TCSs are composed of a histidine kinase and a cognate response regulator. The histidine kinase spans the cell membrane and senses intracellular or extracellular signals including changes in pH, osmolarity, or quorum sensing molecules. Upon sensing appropriate stimuli, the histidine kinase transduces this information via phosphotransfer to a cytosolic response regulator protein that generally functions as a transcriptional regulator. KdpD has been shown to regulate potassium homeostasis in the cell by altering the expression of genes involved in the Kdp high-affinity potassium uptake system [62]. This potassium uptake system is ATP-dependent and responds to very low potassium conditions where other systems cannot support potassium uptake [32]. KdpD-mutated _S. aureus_ displays dysregulated ion channel systems, which lead to lower virulence and decreased survival of bacteria as compared to the wild type. c-di-AMP binds to the universal stress protein domain (USP) within the N-terminal cytoplasmic region of KdpD and inhibits the upregulation of the genes in the Kdp potassium uptake system under salt stress [67].
# Research on Advancing Radio Wave Source Localization Technology Through UAV Path Optimization
## 3 Materials and Methods
### Sequential Estimation Model  
In the previous models, the UAV's trajectory is optimized to minimize the 90 th percentile value of estimation error across all transmission sources. This essentially representsglobal learning.As will be discussed later in the results, estimation errors tend to be significantly degraded in highly obstructed environments, such as the southern area of the Ookayama campus. To address this, as illustrated in Figure 14, sequential learning is introduced to retrain areas that are prone to NLOS conditions. By iteratively updating the estimation model with NLOS-affected sources, this approach aims to enhance estimation accuracy in obstructed regions.
# Machine Learning Applications for Short Reach Optical Communication
## 2 Machine Learning for OPM and MFI in Short Reach Optical Communications
### Direct Detection System
Since the OPM of this work contains multiple tasks, a weighted and hybrid loss function \(L\) is used in the MT-DNN, where the loss function of each OPM parameter is based on ether cross-entropy or MSE [95]:  
\[L=\lambda_{1}L_{1}+\lambda_{2}L_{2}+\lambda_{3}L_{3} \tag{11}\]  
\[L_{1}=L_{2}=-\frac{1}{m}\left[\sum_{i=1}^{m}y_{i}\log_{2}\hat{y}_{i}+(1-y_{i} )\log_{2}(1-\hat{y}_{i})\right] \tag{12}\]  
\[L_{3}=\frac{1}{m}\left(\sum_{i=1}^{m}y_{i}-\hat{y}_{i}\right)^{2} \tag{13}\]  
where \(L_{1}\), \(L_{2}\) and \(L_{3}\) are the loss functions of MFI, BRI and OSNR monitoring, respectively, \(\lambda_{1}\), \(\lambda_{2}\) and \(\lambda_{3}\) are the adjustable weights for the three tasks to optimize the overall monitoring results, \(m\) is the number of samples, \(y_{i}\) is the actual output, and \(\hat{y}_{i}\) is the prediction from MT-DNN. The MT-DNN includes 5 layers with 80, 160, 80, 40, 6 neurons in each layer. The first three layers' activation function is ReLU, whereas in the last two layers, softmax is used for BRI and MFI, and the linear function is used for OSNR monitoring. The accuracy rates of MFI and BRI can reach 100% and 96.8%, respectively [95]. However, the OSNR measurement range of this work is reduced when compared with previous works, limiting to 10-20 dB. Meanwhile, ref. [65] also proposed a multi-functional ML model based on CNN, where MFI and OSNR estimation are realized simultaneously. Different from the use of asynchronous amplitude histogram [95], the eye diagram of the received signal is used as the feature input. Since CNN has the ability of self-feature extraction, it can process the eye diagram in its original form (the pixel value of the image) without having to know other eye diagram parameters (i.e., amplitude, eye histogram, jitter, rise time, fall time) or the original bit information. Therefore, the cost of manual intervention is reduced. In this scheme, the CNN consists of two convolution layers and two pooling layers. The outputs are then mapped into a one-dimensional layer, which is further fully connected to the output layer with 20 neutrons (4 for MFI and 16 for OSNR estimation) [65]. Results show that with 1600 training data, the OSNR estimation accuracy can reach 100%. In addition, 100% accuracy for MFI is also obtained with 800 training data.
## 3 Results and Discussion
During the respiration analysis, the voltage was set at a constant value of 5 V, while the change in the current over time was observed. To monitor the reactivity of the sensor with respect to the distance between the nose and the sensor, measurements were repeatedly performed at distances of 3, 5, and 10 cm. The current value decreased as the distance increased; however, the respiratory response was maintained. In addition, the responses to each distance exhibited almost identical current changes, demonstrating excellent responsiveness. When measuring normal and rapid breathing, the sensor efficiently followed rapid changes in the breathing rate, and the response and recovery times of the sensor were measured to be approximately 0.4 s. This speed is sufficient to measure the respiration rate of humans. Figure 5: High-resolution XPS spectra of the (**a**) Mo 3d core level and (**b**) 2P core level of MoS\({}_{2}\) synthesized via the CVD and hydrothermal methods. The results of this study, indeed, confirm that the crystal structure plays a significant role in enhancing the reaction rate for the absorption and desorption of water vapor and respiration reactions. To achieve a more precise analysis, it is necessary to perform DFT modeling specifically focused on the mechanisms of water vapor adsorption and desorption while considering the crystal structure. It is also necessary to analyze the crystallinity, doping, and defects of the MoS\({}_{2}\) thin film. By identifying the exact mechanism through future research, it will become possible to manufacture a MoS\({}_{2}\)-based respiration sensor with an optimal reaction speed.
# Secure and Time-Aware Communication of Wireless Sensors Monitoring Overhead Transmission Lines
## 4 Transmission Grid Model in Quality of Protection Modeling Language
### Message Passing  
The communication between processes is modeled by means of channels. Any type of data can be passed through the channels. The channels must be declared before the data is passed through. The data can be sent or received by the channels. The channels pass the message in the First In First Out (FIFO) order. When the channels are declared with the non-zero buffer size, the communication is asynchronous. The buffer size equal to zero stands for the synchronous communication. In synchronous communication, the sender transmits the data through the synchronous channel only if the receiver listens on this channel. When the size of the buffer channel equals to at least 1, then the message can be sent through this channel even if no one is listening on this channel. This message will be transmitted to the receiver when the listening process in this channel is executed.
# Novel Generalized Three-Step Phase-Shifting Interferometry with a Slight-Tilt Reference
## 3 Computer Simulation and Optical Experiments
### Computer Simulation
Using the three interferograms and the two extracted phase shifts, wavefront \(\mathbf{O}_{1}\) is retrieved through Equation (12) and then corrected by Equation (22) with the tilt angles of about \(\theta_{x}\) = 0.18 degrees and \(\theta_{y}\) = 0.18 degrees. Back Fresnel diffraction was carried out to obtain the object on the object plane. Figure 3a,b shows the amplitude distributions for the original object wave and the reconstructed object wave. In the simulation setup, the intensity distribution was designed as a Gaussian function to simulate an object wave amplitude. That is to say, the object wave recorded has not only phase distribution but also amplitude variation. Although the amplitude of the original object wave is not uniform, the proposed method can recover it ideally, because there is almost no difference between Figure 3a,b. The phase of the original object wave and its reconstructed phase are shown in Figure 3c,d, respectively. It is difficult for us to find any difference between the two figures. To inspect the phase distribution of the object wave quantitatively, the phase across the center of the zones are plotted in Figure 4. For comparison, the original phase and the reconstructed phase are shown in Figure 4a,b, respectively. Obviously Figure 4a,b are almost identical.
## 2 Materials and Methods
### Laboratory Experiments
#### 2.2.3 Penetrometer Tests  
Penetrometer tests allow measuring the maximum penetration resistance of soil crusts under controlled conditions. This analytical approach has already been applied by numerous studies investigating dust control agents [13; 14; 16; 17; 28; 33; 48; 49]. A penetrometer is a stationary loading machine mounted with a pin to penetrate the soil crust at a set penetration angle and rate, continuously recording the penetration force and depth. [PERSON] et al. [13] concluded that penetration resistance is a good indicator for predicting the dust control performance of a biopolymer and is even better suited than the UCS. In addition, [PERSON] and [PERSON] [17] reported a strong correlation between results from the penetrometer and wind tunnel tests. Thus, penetrometer tests are a recommended and established method for evaluating potential dust suppressants.  
The penetrometer tests were performed with a 6.4 mm (1/4 inch) diameter flat-ended cylindrical penetrometer pin that was mounted to a Wille UL 60/100 loading machine equipped with a 0.001 N resolution calibrated load cell (Institute of Geomechanics and Underground Technology, RWTH Aachen University, Germany). One penetration test was performed in the centre of each sample, pursuing a 4 mm penetration depth at an advance rate of 2 mm/min, a data logging interval of 5 Hz, and a fixed penetration angle of 90\({}^{\circ}\) (Figure 3). Since the penetrometer records penetration resistance alongside the penetration depth, the crusts' modulus of elasticity (M\({}_{\rm e}\), kN m\({}^{-1}\)) could be calculated by dividing the maximum penetration resistance (N) by the penetration depth reached at the moment of rupture.  
Figure 3: Penetrometer testing of fine-grained silica sand sample.
# A Roadside and Cloud-Based Vehicular Communications Framework for the Provision of C-ITS Services
## 3 Roadside and Cloud Architecture
### Cloud Architecture  
The cloud architecture provides support to the roadside architecture by helping to disseminate of important information such as accidents through alerts, and by enabling security and trust in the vehicular network through the public-key infrastructure. Four entities compose the cloudside architecture, namely, the cloud MQTT broker, the central C-ITS platform (MOBICS, road manager), the Public Key Infrastructure (PKI) Certificate Authorities (CAs), and the National Access Point (NAP).