esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Evaluations
### The Measurement of the Enhanced Kapndji Test  
The Kapandji test has a score range of 0 to 10, indicating where a thumb could touch [29] (Figure 2c). The scores of 9 and 10 were omitted because these movements are rarely used in daily life.  
The Kapandji test was performed with various combinations of actuators:  
1. A 3C-ACT for thumb assistance and a conventional single-chamber actuator for four-finger assistance.
2. An M-ACT for thumb assistance and a single-chamber actuator for four-finger assistance.
3. A 3C-ACT for thumb assistance and an M-ACT with three flexion modules connected in series for four-finger assistance.  
Moreover, the clinical Kapandji test only focuses on whether the thumb tip can contact the ten scoring points, though there are multiple thumb-finger postures for achieving the thumb-finger opposition. Figure 2d shows three different thumb-small finger postures for scoring point 6 shown in Figure 2c. Therefore, for the most critical thumb-small finger opposition, we measured three postures illustrated in Figure 2d, which require different degrees of thumb flexion and abduction.  
The air pressure in the thumb actuator and the four-finger flexion actuator were carefully tuned to make the thumb reach the target positions specified by the Kapandji test. We inserted the three-axis load cell between fingers after confirming thumb-to-finger contact to record the change in pinch force with the pressurization of the thumb actuator and the four-finger flexion actuator (Figure 2e). The pinch force was evaluated as the net force of F_X, F_Y, and F_Z.  
For the comparison between the two modular actuators, version 2, with a close-to-thumb bending axis, had a slightly larger flexion angle at each joint than version 1, with a bending axis in the center (CMC, MCP, and IP joints were flexed to 8.8\({}^{\circ}\), 29.7\({}^{\circ}\), and 84.1\({}^{\circ}\), respectively when using version 1, and flexed to 17.5\({}^{\circ}\), 32.3\({}^{\circ}\), and 88.1\({}^{\circ}\) when using version 2).
# Seismic Behaviour of CFST Space Intersecting Nodes in an Oblique Mesh
###### Abstract  
The design of intersecting nodes in high-rise oblique mesh structures is a critical issue. The existing research on the intersecting nodes of oblique meshes mainly focuses on plane intersecting nodes and monotonic axial compression loads. The plane intersecting nodes cannot consider the contribution of the node's out-of-plane angle and floor beam to the node's out-of-plane stiffness in actual structures. In this paper, numerical analysis using ABAQUS was conducted to investigate the mechanical performance of space intersecting nodes of oblique meshes (OMSIN) under cyclic axial tension and compression loads, to provide a reference for the engineering application of oblique mesh structures in seismic regions. Six parameters were considered: the space intersecting angle, the plane angle symmetry coefficient, the plane intersecting angle, the out-of-plane constraint restraint, the steel content of the cross-section, and the concrete strength. The study showed that changes in the thickness of the steel tube wall are unfavourable for the uniform transmission of stress. Increasing the space intersecting angle significantly weakened the seismic performance, and the space angle affects the failure mode of the node. Asymmetric arrangements of the upper and lower plane angles caused nonlinear development of out-of-plane. The ultimate load and overall compressive stiffness of the specimen were positively correlated with the plane angle, and vertical constraints should be applied to the node position of components with plane angles greater than or equal to 70\({}^{\circ}\). The out-of-plane constraint was a key factor affecting the seismic performance of the node, and it was proportional to the ultimate load of the component. In structural design, if the aim is to improve the mechanical performance of the component by increasing the steel content, more enormous out-of-plane constraints should be set to control plane external displacement strictly. The concrete strength is proportional to the ultimate axial load and axial stiffness, and its influence on the mechanical performance in the axial tension direction is not significant. Finally, a dimensionless skeleton curve model of the node was established. The existing formula for the bearing capacity of CFST columns was fitted to obtain the calculation formula for the axial yield and ultimate load of the OMSIN under cyclic loads.  
oblique mesh; intersecting nodes; CFST; numerical analysis; seismic performance +
Footnote †: journal: Applied Sciences
## 3 Results
### Performance Metrics
#### 3.6.1 Root Square Score (R\({}^{2}\))  
The performance metric of the model is evaluated using a root squared score. It is the coefficient of determination [46], that represents the proportion of variance that has been explained by the independent variables in the model. It provides an indication of goodness of fit and therefore a measure of how well-unseen samples are likely to be predicted by the model through the proportion of explained variance. The metric has crucial importance in measuring the efficiency of the model that means that its values range from zero to one [0, 1]. Here zero (0) illustrates that the proposed model does not improve the prediction over the mean model while one (1) implies the perfect prediction.  
If \(\hat{y}_{i}\) is the predicted value of the \(i\)th sample and \(y_{i}\) is the corresponding true value for the total \(n\) sample, the estimated \(R^{2}\) is defined as follows.  
\[R^{2}(y,\hat{y})=1-\frac{\sum_{i=0}^{n}(y_{i}-\hat{y}_{i})^{2}}{\sum_{i=0}^{n} (y_{i}-\overline{y}_{i})^{2}} \tag{1}\]
## 4 Application of UWSN
### Monitoring
#### 4.1.2 Disaster Detection  
Natural disasters are unpreventable phenomena of mother earth. It causes grave damage both financially and the loss of human life. As we cannot prevent it, the next best thing to do is to minimize the loss, and UWSN comes in handy in this part. UWSNs are deployed underwater to sense and send the data to be analyzed to give out warnings giving time for people to relocate and save lives. UWSNs are currently capable of giving a warning for the following disasters:  
* Floods: Sensors are put both on the surface and underwater; they collect information such as water level, force, humidity, temperature, and rainfall and send it to the base station for analysis. There, the data is simulated, and a warning is issued depending on the results.
* Volcanic eruption, earthquake, tsunami: All these can be predicted by sensing the seismic wave underwater. The sensor senses the trimmers and geographical changes, and the data is sent back for analysis. In [80], the authors discussed several approaches for tsunami detection.
* Oil Spill: In the underwater oil field, extraction is complex, and sometimes accidents lead to oil spills which can cause harm to both marine and human life. UWSN helps detect spill location and senses the amount of oil spilled along with the harm it caused to its nearby location. In [81], the authors discussed different architectures including UWSN networks used in monitoring underwater pipelines for oil spills.
# A Family of ACO Routing Protocols for Mobile Ad Hoc Networks
## 3 AntOR-Based Protocol
### Data Structures  
Like almost all of the ACO routing protocols, AntOR requires two data structures: the routing table and the neighbor table. These have a similar functionality as other routing protocols. Each of them is specified.
## 4 Experimental results
### Distributed covariance matrix  
We study in this section the ability of the local covariance hypothesis to properly identify the principal component subspace, and discuss how the accuracy loss is counterbalanced by gains in energy consumption and network load. In Fig. 11, the upper curve gives the amount of variance retained if all covariances are computed, and is the same as in Fig. 7. Lower curves correspond to the percent  
Figure 10: Comparison of the communication costs entailed by a D operation, and A operations with \(1\), \(5\) and \(15\) principal components. Radio range is 10 meters.  
age of variance retained as the radio range of sensors is decreased, and illustrate the fact that the local covariance hypothesis may have as a negative consequence a loss of accuracy for identifying the principal components. If the local covariance hypothesis does not hold, the loss can be high, as is illustrated by a radio range of \(6\) meters. This loss is however attenuated when the number of principal components increases. In any case, the subspace obtained by computing the principal components from the approximate covariance matrix is significantly better in retaining information than a random subspace.  
We note that reducing the radio range also decreases the energy spent in communication, as a lower transmission power leads to a lower energy consumption for the radio. We illustrate in Fig. 12 the potential savings in terms of network load obtained by decreasing the radio range. This figure reports the distribution of the network loads related to the computation of the covariance matrix for varying radio ranges. The average network load increases with the radio range, as the neighborhood of sensors gets larger. Fig. 11 and 12 provide together an illustration of the tradeoff between the accuracy and the communication costs entailed by the local covariance hypothesis. A radio range range larger than \(20\) meters does not bring much gains in terms of accuracy, while it strongly increases the network load.  
Also, it is interesting to compare the results reported in Fig. 12 and Fig. 9. The highest network load caused by an update is in all cases lower using the distributed covariance matrix scheme (\(52\) packets processed against \(101\) at the root for the default data gathering operation). The average network load can however be higher as the radio range increases, due to the fact that nodes close to the leaves process more packets in the distributed scheme than in the centralized scheme.
# In-Orbit Attitude Determination of the UVSQ-SAT CubeSat Using TRIAD and MEKF Methods
## 4 Results
### Discussion and Perspectives
For the eclipse phase and terrestrial flux, the TRIAD method allows us to compute the flux with around 19% uncertainty, although MEKF allows for around 13% accuracy (1\(\sigma\)). The MEKF method brings improvements. but it also presents limitations. The algorithm loads the data on-ground from in-orbit data to compute the CubeSat attitude. However, the method relies on the need to predict the state vector at the next iteration from the previous measurements. Therefore, it is important that those two steps are not too far in time given the chosen sampling rate. Rarely, but not impossibly, the inputs data can be missing due to a single-event upset (SEU) or missing values in the communication process. An example of this appears in Figure 15.  
Figure 13: Difference between the precision (**a**) and accuracy (**b**) of the MEKF and the TRIAD methods based on the UVS indicator (positive means that MEKF has better performance compared to TRIAD). After the missing values, the first estimations of the nadir component from the MEKF method seem to be very different from the TRIAD estimations. Data gaps cause the poor prediction of the next iteration. This issue can be solved by implementing the algorithm on-board the satellite to avoid missing values due to communication issues. To do so, the computations should be executed on the on-board computer. Computational resources can be limited in-orbit. Therefore, an optimized algorithm was developed to reduce the required computations and is described in [15]. This section has presented the results of the methods. The advantages and limitations can be summarized as follows. The use of infrared sensors instead of photodiodes in an eclipse allows us to greatly reduce the measurement uncertainty. This is still recent  
Figure 14: Uncertainties estimated from the Monte Carlo method for TRIAD and MEKF methods for continuous sampling on 2 March 2021 (**top**) and from 11–13 March 2021 (**bottom**) with eclipse phases in gray. Figure 15: Nadir Z component in the satellite frame based on the TRIAD and MEKF methods—missing values are delimited with hatches for a 10 min duration on 3 February 2021.  
and rarely developed in the literature (Table 1, such as in [12] or [19]), but its use could be validated in orbit. Moreover, the use of the Kalman filter allowed us to increase the accuracy of the attitude restitution and is relatively computationally efficient compared to the Unscented Kalman Filter presented in [19]. However, certain limitations are present due to difficulties of a making predictions due to a lack of data.
# Road Infrastructure Investment Limits Based on Minimal Accidents Using Artificial Neural Network
###### Abstract  
Road traffic accidents are still among the top major global causes of death, injury, and disability. Despite this cause for alarm and several preventive initiatives, global road accident statistics are not improving. This study modeled annual road accidents (ARAs) as a function of demographic, economic, passenger movement, freight movement, and road capital investment indicators. The research is based on 22 years of data from more than 36 Organization for Economic Co-operation and Development (OECD) member and partner countries. Artificial neural network (ANN), multiple linear regression (MLR), and Poisson regression (PR) analysis were employed for this purpose. The ANN model outperformed the regression models by far, thus making it possible for reliable new insights and accurate results to be obtained. The ANN's superior performance was shown to be a result of the non-linear relationship between ARA and some of the predicting variables. The average relative contribution of each variable in describing the ARA models was estimated using connection weight analysis (from the ANN model) and relative weight analysis for the regression model. The profile method was used to perform sensitivity analysis and to establish the partial variation trend of the ARA with each of the variables. The Existing Road Maintenance Investment (ERMI) and New Road Infrastructural Investment (NRII) showed a nonlinear concave-up relationship with ARA for given demography, economy, freight, and passenger movements. A combination of per capita NRII and ERMI corresponding to the minimum ARA exists. These sets of NRII and ERMI were considered safe road investment limits. The ANN-ARA model was utilized to estimate these limits with their relative proportion for diverse combinations of demography, economy, freight level, and passenger movement.  
Keywords:road investments; road traffic accidents; artificial neural network; gross domestic product (GDP); demographics +
Footnote †: journal: Applied sciences
# Power Losses Investigation in Direct 3 \(\times\) 5 Matrix Converter Using MATLAB Simulink
## 1 Introduction  
Matrix converters gained considerable interest in the sphere of research and universities in recent years [1; 2; 3; 4]. In high power density applications [4; 5] or applications with large temperature variations, the lack of the DC-Link capacitor or inductor is beneficial over the normal VSI design.  
Direct matrix converters (DMCs) were long viewed as an appealing AC/AC choice due to their sinusoidal input/output currents, bidirectional power flow, and customizable input power factor. As a result, it is a competitive topology that may be used in a wide range of electrical equipment, including industrial pumps, cooling, refrigeration, elevators, belt transportation systems, and avionic applications [6; 7].  
Direct matrix converters (DMCs) and the bidirectional switches (BDSs) have changed throughout time. Each BDS, in an instance, can be achieved by a single monolithic device [7], which is not yet accessible, or by some combination devices [8; 9] to offer bidirectional current conduction when activated and bidirectional voltage blocking when deactivated. Because a bidirectional switch constructed in a single monolithic semiconductor that could conduct and block current and voltages in both directions is not available, bidirectional switches must be designed utilizing discrete components such as IGBTs, MOSFETs, or RB-IGBTs. However, recent news from new GaN technology may overcome this problem, and researchers recently focused their efforts on this area as well [10; 11; 12].  
When a high-power density is required, the power loss analysis is an important aspect of the converter design approach. If power losses are not examined under various operating situations, the cooling solution design may be insufficient. The analytical technique is a common procedure for calculating losses. This method can be time-demanding due to the extensive analysis of the matrix converter increased number of semiconductors [13; 14; 15; 16; 17; 18; 19]. Another method is to use numerical analysis with semiconductor models. If transistor models are available, this technique is more efficient [20].  
If any operating circumstances, such as converter start-up, fault conditions, and others, must be evaluated, numerical analysis is particularly helpful. The goal of this study is to analyze the potential benefits of SiC transistors in matrix converter applications, as stated in the switch analysis part of this paper. The transistor and diode models were used to mimic the power component of the matrix converter in a 3 \(\times\) 5 arrangement suited for multiphase drives [21]. In addition, all of the power components of the matrix converter's building parts, such as the protection network, current direction detecting circuit, and input filter, were simulated to determine the entire efficiency of the converter.
# Design of Time-Synchronized Switch Based on Zynq
###### Abstract  
In the context of the rapid development of modern science and technology, time synchronization technology has become a critical support in the fields of communication and scientific research. Especially in large-scale research projects such as the China Spallation Neutron Source, the accuracy of time synchronization directly affects the precision of experimental data and the reliability of experimental results. White Rabbit (WR) technology surpasses the sub-microsecond precision limitations of traditional PTPs by precisely controlling and calibrating the delays between master and slave clocks, achieving sub-nanosecond time synchronization that meets the stringent timing accuracy requirements of 5G networks and quantum communications. To meet the demands for high precision, high flexibility, and broad applicability, a switch with WR functionality has been designed based on the Zynq platform. This design not only reduces the number of required components and the complexity of the soldering process but also allows for simple AXI bus communication between the PS and PL ends, thereby decreasing the development time and cost of both software and hardware. The hardware design includes power circuits, clock circuits, and SFP interface circuits. The time synchronization module encompasses the design of the RTU, NIC, SoftPLL, and PPS modules, as well as the design of the AXI to Wishbone bridge. Testing has shown that this switch can achieve sub-nanosecond level time synchronization accuracy.  
Keywords:white rabbit; Zynq; time synchronization; switch +
Footnote †: journal: Applied sciences
###### Abstract  
In this study, a bipolar optical code-division multiple-access (Bi-OCDMA) technique based on spectral amplitude coding (SAC) was proposed by using a phase modulator to realize polarization coding through a free-space optical (FSO) channel. Various types of noise, such as amplified spontaneous emission (ASE) noise, thermal noise, and shot noise, were included in the simulation to approach the real application. The first simulation, utilizing a modified M-sequence as signature code, demonstrated that the proposed Bi-OCDMA system could be implemented in FSO communication. The proposed Bi-OCDMA scheme improves the transmission rate and power efficiency compared with the previous scheme. The structure of the proposed system alleviates multiple-access interference (MAI) with a simple and cost-effective design. The second simulation observed the performance of the proposed Bi-OCDMA for two users with several well-known SAC codes, i.e., multi-diagonal (MD) code, modified quadratic congruence (MQC) code, modified maximum length sequence (M-sequence) code, and Walsh-Hadamard code, in extreme weather conditions, both for additive white Gaussian noise (AWGN) and turbulence-induced fading channel. The simulation results indicated that the Walsh-Hadamard code has superior performance compared to other codes. The results show the MD code can be implemented in the proposed Bi-OCDMA scheme for a medium-distance FSO.  
bipolar; phase modulator; polarization coding; free-space optical communication; multiple-access interference (MAI); optical code-division multiple-access (OCDMA)  
1  
[PERSON]; [PERSON] [PERSON] Design of Bipolar Optical Code-Division Multiple-Access Techniques Using Phase Modulator for Polarization Coding in Wireless Optical Communication. _Appl. Sci._**2021**, _11_, 5955. [[https://doi.org/10.3390/app11135958](https://doi.org/10.3390/app11135958)]([https://doi.org/10.3390/app11135958](https://doi.org/10.3390/app11135958))  
1
## 1 Introduction
Indeed, experimental results and channel models are applied to the Wi-SUN channel simulation for different values of data rates [26]. Therefore, it is necessary to understand the distinct channel characteristics of communication links to enhance the performance of any installed communication scheme. Hence, studying these characteristics is essential in order to develop optimal communication solutions and ensure system reliability. This involves selecting the most suitable channel, whether it is PLC or RF, across various topologies, such as rural, urban, and industrial settings, as well as different noise profiles. In this regard, the main objective of this paper is to establish a novel approach for ensuring uninterrupted communication between the SM and DC in the advanced metering infrastructure (AMI) system, with a focus on achieving optimal performances in terms of the BER across three distinct environments, as illustrated in Figure 1. The proposed method outlines a dependable communication system that relies on a NB-PLC medium when the wireless signal is compromised or weakened due to obstacles or disruptions, and on a wireless medium when the PLC signal is negatively impacted by excessive noise or an impedance mismatch. In Section 2, the authors outline the key characteristics of RF and NB-PLC systems. Section 3 provides an overview of various environments: rural, urban, and industrial. In Section 4, the impacts of these environments are analyzed through simulations using both NB-PLC and RF systems. The parameters for each system are set based on IEEE 1901.2 for NB-PLC and IEEE 802.15.4g for RF. The results demonstrate the appropriateness of each link in relation to a specific scenario, considering factors such as multipath effects and the type of noise as indicators of channel performance.