esa-sceva/satcom-chunk-collection huggingface dataset:
###### Abstract  
Wave Glider is an autonomous surface vehicle that directly uses wave energy to generate forward power and has been widely used in marine survey and observation. Wave Glider is composed of surface vessel, submersible propeller and the connection structure between them. Connection types are thought to be related to the performance of Wave Glider closely. In this paper, the effects of the connection structure between the surface vessel and the submersible propeller on the motion performance of the Wave Glider are studied. Several connection types such as rigid rod, cable, multi-link chain and elastic rod are applied to connect the surface vessel and the submersible propeller. The models of connection structures are developed respectively. Among them, cable model is established with a finite number of small cylinders, which connected by spring and damping elements; multi-link chain can be seen as hinged by multiple rigid rods; elastic rod model can be looked on as several segments linked with elastic components. Considering the connection characteristics, the integrated dynamic models are established by applying multi-body dynamics software ADAMS (Automatic Dynamic Analysis of Mechanical Systems) with consideration of the hydrodynamic forces on different components of Wave Glider. The propulsion performance of the Wave Glider is calculated by using numerical method, and the simulation results showed that the difference of propulsion performance with different connection types of the Wave Glider is slightly. But serious impacts can occur on the connections of rigid rod and multi-link chain. They can lead to serious extra load on the structure of Wave Glider. From the engineering practice of Wave Glider application, the cable connection is more convenient to transport, deploy, recover and store. It is also the generous connection type for wave glider.  
Wave Glider; connection structure; dynamic performance; wave energy utilization 1
## 3 Measuring System  
The bimodal AFM measuring system based on the Akiyama probe shown in Figure 15 is built to utilize this feature to measure the power dissipation. Two lock-in amplifications (LIA) excite the probe and demodulate the output signal. The first eigenmode signal amplitude is sent to the feedback system to control the PZT (piezoelectric ceramic transducer) to keep the distance between the tip and the sample constant as normal tapping mode, the position of the PZT describes the morphology of the sample. The second eigenmode signal amplitude is recorded, as mentioned above, this is related to the power dissipation therein.  
The setpoint of the first eigenmode signal is 0.6 \(A_{01}\), the amplitude ratio of the two signals is \(A_{01}/A_{02}=0.723\) V/0.503 V \(\approx\) 1.437, where \(A_{01}\) and \(A_{02}\) are the amplitude of the first and the second eigenmode signals without contact. Parameters of the probe: the eigenfrequencies are \(f_{01}=46.162\) kHz, \(f_{02}=202.646\) kHz, cantilever spring constant \(k\approx 5\) N/m, quality factors: \(Q_{1}=1154\), \(Q_{2}=6776\). The scanning speed is 250 nm/s. There are 220 measured points along the length of 8760 nm.
## 3 Methods
### Fine Feature Extraction Module  
FFE is specifically designed to tackle the challenge posed by the low damage ratio in pavement images. This module employs depthwise separable convolution techniques to handle each channel separately, followed by linear combination of the depthwise convolution outputs to mix information from different channels. This approach enhances the feature representation capability. Figure 2 illustrates the structure of FFE, and the expression formula is given in Equation (6). This module primarily consists of depthwise separable convolution, complemented by a BatchNorm2d layer for normalization and a ReLU activation function for nonlinear activation. Additionally, residual connections are incorporated to prevent information loss.  
When the input tokens enter the FFE module, they first undergo depthwise separable convolution with a kernel size of \(3\times 3\), a stride of 2, and padding of 1. This convolution maintains the same dimensionality as the original input to avoid information loss due to dimensional changes. After performing convolution separately on each channel, the outputs are linearly combined to mix information across different channels, enhancing inter-channel information transfer. Subsequently, Batch Normalization and ReLU activation are applied to improve model stability and feature representation capabilities. A residual connection is then added to prevent information loss. Finally, another ReLU activation is performed to obtain the final processed result, which is then passed to the multi-head self-attention module for subsequent classification tasks.
# A Trustworthy Communication Hub for Cyber-Physical Systems
## 4 Building Blocks of the CPS Communication Hub
### Presence Management  
The need for presence management arises from the inherent characteristics of physical CPS asset devices and services (resources) to be online or offline at any given time. The reasons for being offline may be related, for example, to power sources, unreliable communication links, mobility, or the user/owner needs. When such a resource needs to be reachable via communication networks, it should register its presence into a known place. According to our approach, such a place is the virtual communication space of the resource owner.  
When speaking about resources, an essential problem to be solved is related to identities and addressing. There are several solutions for identities in different levels of the systems. For example, medium access control (MAC) addresses are in use in the radio access level, Internet protocol (IP) addresses, and Uniform Resource Locator URLin Internet/Web contexts, service provider specific addresses in enterprise systems, and e.g., Universally unique identifier (UUID) to identify resources have been proposed, among others. Here, identities and addressing refer to the ones used at the communication level, more specifically in the communication overlay level and especially related to the concept of virtual communication space.  
The problems for the identities and addressing in the communication overlay level arise from the mobility, use of local identities, dynamic presence, and topics of shared information. Local identities and addressing, such as IP and physical level addresses, may be temporal; therefore, more reliable ways for identifying resource owners and the resources themselves are needed. Basically, the generally applied \"scheme:[//host[:port]][/path]\" could be applied; however, it lacks references to the ownership of resources. Therefore, identities and addressing for virtual communication spaces at the communication overlay level are specified using the following notation:  
\[\textless{owner}\textgreater{@}\textless{domain.server}\textgreater{/} \textless{physical resource}\textgreater{/}\textless{logical resource}\textgreater \tag{1}\]  
where  
* _<owner>_ denotes the resource owner;
* The home domain of the owner is _<domain.server>_;
* _<physical resource_> refers to a physical resource, which can typically be, for example, embedded devices, gateways, or servers;
* The optional part _<logical resource_> can refer to any specific information content, or to logical resource tree of the information or, for example, a semantic Web type of resource.
# Molecular and Functional Evolution of the Spermat Sesquiterpene Synthases
## 2 Results
### Predicting the STS Functions through Functional Evolution Analysis  
Three STSs, _CaSTS2_, _CaSTS3_, and _CaSTS4_, were obtained from the _Celastrus angulatus_ raw sequence reads deposited in NCBI (STUDY: PRJNA509518) [32]. They were predicted not to contain the plastid-targeting peptide (predicted by ChloroP v. 1.1 and TargetP prediction programs), suggesting that they function as STSs in _C. angulatus_[33]. As shown in the phylogenetic tree, _CaSTS2_, _CaSTS3_, and _CaSTS4_ were assigned to Clade I in the TPS-a subfamily (Figure 8). Clade I is the germacrene A synthase clade, members of which have highly conserved DDxxD and NSE/DTE motifs, responsible for binding of the substrate diphosphate group. Most Clade I STSs catalyze C10-C1 closure to form mono- or double-ring sesquiterpenes. It is widely known that conventional STS functional prediction based on sequence similarities is inaccurate; however, clarifying the functional evolutionary status may provide an alternative strategy for STS functional analysis. According to this, we speculated that these three _CaSTSs_ may be 1,10-cyclized STSs, and their mechanism of product formation is similar to the germacrene A synthase.  
In order to verify the predicting results, we characterized _CaSTS2_, _CaSTS3_, and _CaSTS4_ experimentally, by heterologously expressing these three _CaSTSs_ in an engineered _S. cerevisiae_ strain LWG003. GC-MS analysis results (Figure S1) showed that _CaSTS2_, _CaSTS3_, and _CaSTS4_ catalyzed the formation of germacrene D (C10-C1 closure), similar to our previous study in vitro [33], which is consistent with the functional evolutionary analysis. This demonstrates an application of the structure-based phylogeny in predicting STS function.  
Figure 8: The phylogeny of candidate STSs in _C. angulatus_. Red branches represent the _CaTPSs_. The red underlines show the conserved DDxxD and NSE/DTE motifs.
## 4 Proposed Model
### Constraints and Preferences  
Several constraints and preferences can be incorporated into the model to simulate some realistic aspects of the problem. The most important are:  
* the travel time of each vessel does not exceed a specified value;
* the passenger travel time does not exceed a specified value;
* the service time of a particular island does not exceed a specified value;
* a desired priority for serving a particular island can be set;
* a specific island may be served directly from the central port;
* a minimum and/or maximum number of islands served by a single vessel can be set;
* constraints regarding islands' (operational) capability to serve as hub nodes can be set.
# Fast Cylinder Shape Matching Using Random Sample Consensus in Large Scale Point Cloud
###### Abstract  
In this paper, an algorithm is proposed that can perform cylinder type matching faster than the existing method in point clouds that represent space. The existing matching method uses Hough transform and completes the matching through preprocessing such as noise filtering, normal estimation, and segmentation. The proposed method completes the matching through the methodology of random sample consensus (RANSAC) and principal component analysis (PCA). Cylindrical pipe estimation is based on two mathematical models that compute the parameters and combine the results to predict spheres and lines. RANSAC fitting computes the center and radius of the sphere, which can be the radius of the cylinder axis and finds straight and curved areas through PCA. This allows fast matching without normal estimation and segmentation. Linear and curved regions are distinguished by a discriminant using eigenvalues. The linear region is the sum of the vectors of linear candidates, and the curved region is matched by a Catmull-Rom spline. The proposed method is expected to improve the work efficiency of the reverse design by matching linear and curved cylinder estimation without vertical/horizontal constraint and segmentation. It is also more than 10 times faster while maintaining the accuracy of the conventional method.  
point cloud; RANSAC; Catmull-Rom; pipe estimation; PCA; Lidar; spline; detection; iterative method; random sample +
Footnote †: journal: Applied Sciences
# Task-Oriented Evaluation of the Feasible Kinematic Directional Capabilities for Robot Machining
## 1 Introduction
Only pure translational (rotational) motion can be analyzed by the translational (rotational) manipulability polytope in a strong sense [36; 38; 39], but such applications, especially in the case of the robot surface machining, rarely exist in practical industrial cases. Some more recent approaches have evaluated the maximum directional kinematic capability using optimization-based methods in the case of redundant manipulators [40; 41], which are mostly used in the case of redundant robot manipulators. If suitable linear inequality constrains related to the specific task requirements can be defined, the formulation of the optimization problem can also be adopted for robot machining purposes. However, finding the solution in this way is a time-consuming process. Generally, none of the above-mentioned methods seem to be suitable nor optimal, nor do any of them involve an appropriate consideration of the scenario when synchronized translational and rotational motion is required. For this reason, we propose a method called Decomposed Twist Feasibility (DTF) in order to determine a feasible linear and angular velocity for robot machining purposes. In contrast to the existing methods that estimate maximum directional capabilities, it can precisely determine maximum motion capabilities for translation and rotation while considering the exact joint velocity limits and specific task requirements. Physical consistency can be achieved since the translational and rotational performance capabilities are considered individually. In contrast to the polytope approach, our solution can be computed in a time-efficient manner. The test results based on a generic 3 DOF planar robot manipulator and a collaborative robot UR5e demonstrate the usefulness of the proposed DTF method. The remainder of this article is organized as follows. The related research based on the manipulability ellipsoid and polytope is described in Section 2. In this section, we also introduce a DTF method to determine the feasible linear and angular velocity in synchronous motion, which is required in applications such as robot surface machining. In Section 3, the numerical test results of the proposed DTF method in the case of a generic 3 DOF planar robot mechanism and a collaborative robot UR5e are shown in the context of the twist manipulability polytope, which proves the effectiveness and usefulness of the proposed DTF method. Finally, a discussion with conclusions is given in Section 4.
###### Abstract  
Transition zones in railway tracks are the locations with considerable changes in vertical support structures, e.g., near bridges. Due to possible water flow constrictions in transition zone structures, there is frequently an increased moisture level in the ballast/subballast layers, which is a potential source of track degradation. This paper presents results of the moisture condition measured in three transition zones using ground penetrating radar, where the ballast/subballast are analyzed. The relationship between the moisture condition and track degradation in the transition zones is studied by comparing it to the longitudinal track level that is measured by the track inspection coaches. A strong connection is found between the high moisture condition and track degradation in the transition zones. The dynamic behavior of the transition zones with high moisture condition is analyzed using the Finite Element method. Differential stiffness and settlement are taken into consideration in the transition zone model, which is also coupled with a vehicle. The ballast/subballast layers are modelled as solid elements. Increased moisture conditions are considered as a reduction of elastic modulus, according to laboratory findings. Results show that high moisture leads to an increase of dynamic wheel loads in the transition zone, which explains the connection and confirms that the high moisture condition is a source of transition zone problems.  
Keywords:bridge transition zone; railway; moisture condition; ballast; finite element method; track degradation +
Footnote †: journal: Applied Sciences
## 1 Introduction
Yet, the short wavelength imposes a change in the infrastructure, hence the need for more base stations to cover the same area covered by other wireless technology. This new structure imposes more threats, such as fake base stations. It is essential to understand the security risks and potential solutions. In this work, we aim to provide an overview of the IoT applications, benefits, and potential risks. Additionally, to build a framework to study and further develop best security practices by either implementing and analyzing current existing schemes or developing new ones. Based on the findings, we provide recommendations to avoid such risks and to remedy the possible security vulnerabilities. This work will guide regulatory agencies to continue enforcing policies, educating end-users and entities, and stakeholders involved in IoT to develop and apply more appropriate security and privacy measures. We built our model using Amazon Web Service (AWS) as proof of concept, which later translated to actual physical systems of sensors nodes mimicking general IoT structure. By making the system, we can deploy and study different security approaches by building real sceneries and benchmarks. We adopted a narrative review methodology to explore the history and background of the IoT systems, their security and privacy issues, and the corresponding countermeasures. We proposed our own view of the generic and stretched IoT model and its privacy and security concerns. We built and studied a cloud/edge supported IoT model consisted of a virtual machine (sensors), and edge node (Raspberry Pi), and cloud services (AWS). This setup was designed to evaluate the model we proposed in the following sections in this paper. Our work does not provide details on the different IoT applications (smart health, smart cities, supply chain, transportations, etc. ); their features, advantages, and challenges, or the possible security risks or threats among these applications. The literature is rich with such content. In this work, we preferred to have a general overview with proof of concept and lay the ground for further analysis and investigations. The rest of this paper organized as follows: the next section presents a literature review followed by IoT security and privacy challenges. In Section 4, we discuss the future of the Internet of Things. Section 5 presents the proposed cloud/edge supported IoT layered models: generic and stretched with the privacy and security components and layers identification. This section also shows the implementation of the proposed model using AWS cloud and edge environments and Raspberry Pi 4 kit. Section 6 concludes this work.
# Precipitation Products' Inter-Comparison over East and Southern Africa 1983-2017
## 5 Discussion
The agreement between CHIRPS and TAMSAT3 was expected; however, a possible explanation for the behavior in SA can be found in the relative weights associated with the various input data in MSWEP, summarized in Section 4.3. Generally, the MSWEP estimates are more based on rain gauges in SA than in EA for the whole analyzed period, and this could contribute to the MSWEP vs. CHIRPS similarity, considering that CHIRPS exploits rain gauges for bias correction of its IR-based precipitation estimates, whereas TAMSAT3 uses only historical rain gauge measurements to calibrate the CCD in a seasonally and spatially varying climatological calibration procedure that does not change from year to year. Moreover, as the climate of SA is strongly influenced by the presence of the Atlantic and Indian Oceans, and by frontal systems, it is possible that TAMSAT3 shows a lower capability to identify non-convective precipitation compared to the other two datasets, given the difficulty in detecting precipitation falling from warm-top clouds, which are not captured by the threshold temperatures adopted for identifying precipitating cloudy systems (Kenyon, 2016; Kenyon, 2016).
# Parametric Analysis of Compliant End Face Gas Film Seals Considering Slip Flow Effects
## 4 Results and Discussion
### Influence Law of Structural Parameters
#### 4.3.3 Influence Law of Wave Foil Pitch  
The value range of the wave foil pitch was selected to be 1.50-2.50 mm, the other parameters remained unchanged, and the sealing characteristic parameters with the change rule of the wave foil pitch considering the slip flow effect and not considering the slip flow effect were obtained, as shown in Figure 11.  
From Figure 11a, it can be seen that as the wave foil pitch increases, the gas film opening force then increases nearly linearly, and the gas film opening force without considering the slip flow effect is larger than the gas film opening force when considering the slip flow effect. Under the condition of the same minimum gas film thickness, the rising gradient is basically the same considering the slip flow effect and not considering the slip flow effect, which is due to an increase in the pitch, the wave foil is more prone to deformation in the axial direction, and the end face wedge effect is more prominent, which makes the gas film opening force increase. As the wave foil pitch increases over this range of variation, the mass leakage rate increases for the same minimum gas film thickness, both considering the slip flow effect and not considering the slip flow effect.  
According to the relationship curves in Figure 11b, it can be seen that the viscous friction power consumption and stiffness leakage ratio show a decreasing trend as the pitch of the wave foil increases, and the slip flow effect exacerbates the decrease in the viscous friction power consumption. When the minimum gas film thickness is 1.25 \(\upmu\)m, the viscous friction power consumption without considering the slip flow effect decreases by 1.81 W, a relative decrease of 24.78%, and the viscous friction power consumption with considering the slip flow effect decreases by 0.83 W, a relative decrease of 13.91%, with an increase in the wave foil pitch. This suggests that the presence of slip flow effects reduces the rate of reduction in the viscous friction power consumption. Through Figure 11b, it is found that the rate of decrease in the stiffness leakage ratio increases with an increase in the minimum gas film thickness, which shows that the setting of the minimum gas film thickness is more critical to the stiffness leakage ratio.
## 4 Anomalous Hall Effect in Antiferromagnetic Topological Semimetals
Because the charge carrier density is normally very small in compensated ferrimagnets, the signal of the AHE is very weak. However, if there are some special topological band structures, such as nodal lines and Weyl points, the AHE should be strongly enhanced. A possible candidate is the Heusler compound Ti\({}_{2}\)MnAl [69], where the zero net magnetic moment is due to the opposite magnetization from Ti and Mn sites.
# State Estimation of Over-Sensored Systems Applied to a Low-Cost Robotic Manipulator
## 4 State Estimation
### Link Model Estimation
#### 4.1.3 Encoder Model  
If the encoder model is correctly implemented, the \(z\) component of the rotation vectors obtained from the orientation estimates of each link should perfectly match the baseline angles since the baseline is obtained using the encoders. This is mostly verified in Figures 10-12.  
There are slight changes noticeable when a different encoder detects movement. For example, at 10 s, which is when \(\theta_{3}\) changes, \(\theta_{2}\) is slightly affected by that movement. This is a natural consequence of the way \(\omega_{i}\) was modeled. Since it follows a random walk model, there should be some inertia when altering the orientation of a link. For example, if \(\theta_{3}\) changes, then the expectations of the model for Links 2 and 3 to stand still force \(\theta_{2}\) to also change. However, the lack of a change in that joint detected by its encoder quickly reverts this small effect.  
Figure 9: Evolution of Rotation Vector 3 when testing the link model using only accelerometer measurements.