esa-sceva/satcom-chunk-collection huggingface dataset:
# A Velocity-Aware Handover Trigger in Two-Tier Heterogeneous Networks
###### Abstract  
The unexpected change in user equipment (UE) velocity is recognized as the primary explanation for poor handover quality. In order to resolve this issue, while limiting ping-pong (PP) events we carefully and dynamically optimized handover parameters for each UE unit according to its velocity and the coverage area of the access point (AP). In order to recognize any variations in velocity, we applied Allan variance (AVAR) to the received signal strength (RSS) from the serving AP. To assess our approach, it was essential to configure a heterogeneous network context (LTE-WiFi) and interconnect Media-Independent Handover (MIH) and Proxy Mobile IPv6 (PMIPv6) for seamless handover. Reproduction demonstrated that our approach does not only result in a gain in relatively accurate velocity but in addition reduces the number of PP and handover failures (HOFs).  
mobility management; heterogeneous networks (HetNets); IEEE 802.21 MIH; Proxy MIPv6; Network Simulator 3 (NS3) Article
## 3 Network Sliced Distributed Learning
### DL-as-a-Service for IoV Applications
#### 3.2.2 DLaaS Advantages  
The proposed DLaaS approach introduces several advantages in terms of performance enhancement, flexibility, scalability, and intelligence. With the presence of multiple DL slices, the IoV system has _better performance_ in terms of latency, energy costs, and overall learning performance. DLaaS allows different DL functions to be implemented on distributed platforms according to their specific requirements, local network conditions, and resource availability. This can improve performance by allowing several users/devices to participate in the learning process efficiently. Implementing various DL methods as slices on distributed computing platforms can provide additional _flexibility_ in terms of resource sharing and slice function deployments. The NS approach also allows for better _scalability_,as it can enable a higher number of DL methods. This approach can also boost vehicle _intelligence_ through the deployment of several possible DL slices simultaneously.
# Review of sEMG for Robot Control: Techniques and Applications
## 4 Application of sEMG Interface in Robot Control
### Classification of Robot Control Strategies
#### 4.1.2 Semi-Autonomous Continuous Control Strategy (S2)  
This strategy frequently requires a combination of many sensors, notably vision, for perception. The robot system follows the sEMG signal for movement and then uses signals from additional sensors to sense the surrounding environment and objects, further determining the user's motion intention and automatically executing a pre-programmed task template to aid in fulfilling the task.  
[PERSON] provides shared control templates, which employ the subject's sEMG signals to direct the robotic arm's motion by combining visual perception from a camera with pre-set task action templates, such as drinking water, opening doors, and picking up objects. Based on this, the control computer infers the user's task intention and calls a shared control template for the robotic arm to aid the user in performing the task. During this procedure, the motion of the robotic arm is no longer solely determined by the sEMG signals [16; 25; 83].  
[PERSON] employs a different semi-automatic control method, extracting only the direction of movement from a recorded sEMG signal with a predefined speed and joint torque for the movement of a robotic arm [60]. Activation of the hand extensor and abductor pollicis brevis muscles controls the opening and closing of a wearable five-fingered mechanical hand with the motor moving at a constant angular velocity, as described in [42]. This artificial hand was utilized for hand rehabilitation training after a stroke.
# Optimized Wireless Sensor Network Architecture for AI-Based Wildfire Detection in Remote Areas
## 4 Experimental Results
### Computational Complexity Analysis
#### 4.3.1 Routing Complexity  
The adaptive routing algorithms achieve sub-linear complexity through topology-aware optimizations. For dense forests, inter-tier routing enables vertical jumps between concentric circles, reducing path lengths to \(O\big{(}\sqrt{N}\big{)}\) hops (Equation (5)). In non-dense forests, the hybrid adaptive-semi-adaptive approach limits intra-tier routing to axis nodes, yielding \(O\big{(}\sqrt{N}+log\sqrt{N}\big{)}\) complexity (Equation (6)). This represents a 50-60% reduction in hop count compared to 2D Mesh topologies, which exhibit linear \(O(N)\) scaling (Equation (7)). The tiered structure ensures routing decisions remain \(O(1)\) per hop, as nodes select dynamically neighbors without exhaustive path searches.
# Designing an Adaptive Underwater Visible Light Communication System +
## 10 Conclusions  
UVLC is emerging as a promising solution for underwater communication. Accurate data transmission depends on the precise positioning of both the receiver and transmitter. By carefully selecting the optimal PPM level and angular alignment to minimize signal degradation, UVLC systems have the potential to outperform existing underwater communication technologies. NLOS communication is also achievable with UVLC. Real-time experiments suggest that the BER is zero when the alignment is perfect for the adaptive system, but the BER approaches 0.3 with 80-degree misalignment. Nevertheless, the performance could be further improved with a better receiver with a wide field of view to accommodate the transmitted beam. Additionally, the experimental trials using Li-Fi, an SDR, and a positional servo motor demonstrate that the adaptive system design is practical and convenient. Future improvements can be realized by implementing robust algorithms that enhance synchronization and overall system performance. In conclusion, the adaptive alignment system demonstrates strong potential for real-time UVLC applications, but challenges related to synchronization and power differentiation at small angular displacements must be addressed to enhance its performance in both LOS and NLOS conditions.  
Conceptualization, S.R. and P.C.; Writing--original draft, S.R.; Writing--review & editing, Y.R.; Supervision, Y.R. and P.C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
Data Availability Statement: Data is available upon request.  
The authors declare no conflict of interest.
# Visible Light Communication System Technology Review: Devices, Architectures, and Applications
## 6 VLC Application
### Li-Fi  
Li-Fi is similar to Wi-Fi, but it is a bidirectional, visible light wireless communication system. In 2011, [PERSON] first created Light Fidelity (Li-Fi). Wi-Fi signals have the problem of interference with other radio signals, such as interfering with the airplane navigation equipment. Hence, Li-Fi can be a better solution in areas sensitive to electromagnetic radiation, such as airplanes and hospitals, which is illustrated in Figure 15.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Mobile** & **Vehicle** & **Infrastructure** \\ \hline Fixed coordinator & No & No & Yes \\ Power supply & Limited & Moderate & Ample \\ Form factor & Constrained & Unconstrained & Unconstrained \\ Light source & Weak & Intense & Intense \\ Physical mobility & Yes & Yes & No \\ Range & Short & Long & Short/Long \\ Data rate & High & Low & High/Low \\ \hline \hline \end{tabular}
\end{table}
Table 5: Classification of IEEE 802.15.7 devices.
# Noise Control in Air Mechanical Ventilation Systems with Three-Dimensional Metamaterials
## 2 Literature review on 3D metamaterials
It is a two-dimensional structure placed in Madrid, composed of circular scatterers of 30 mm diameter, organized in a regular net frame having a constant distance of 100 mm between nodes. Some acoustic measurements showed that this configuration has a significant sound attenuation at 1700 Hz [15; 16; 17; 18; 19]. Other types of applications have been undertaken for the noise control of ships and submarines by employing Alberich coatings. This structure is composed of macro sequences periodically arranged, mostly applied to the cladding of underwater submarines to reduce echoes. This solution was introduced by Germans during the World War II by coating the submarines with resonant cavity lattices provided with sound absorbing properties [20; 21; 22; 23]. Further developments can be achieved with the employment of three-dimensional printers, capable of realizing complex geometries to be used in the field of metamaterials. With the change in geometry and with the variation of the volumes of the objects, a sound attenuation can be obtained in the desired frequency range, a condition that often cannot be achieved with the traditional sound absorbing materials. The regular structures of the metamaterials can also be used to improve the sound absorption of membrane systems, in fact a membrane placed at a distance (\(d\)) from a rigid surface absorbs the frequency components equal to \(\lambda/4\). Therefore, to absorb a frequency component equal to 100 Hz, a cavity with a thickness (\(d\)) of 0.8 m is required, while to absorb a frequency component equal to 1000 Hz, a cavity with a thickness (\(d\)) equal to 0.08 m is required. The results related to sound absorption through the membrane have a bell-shaped trend with a maximum attenuation corresponding to the frequency considered. by adding appropriate masses to the membrane, it is possible to increase the membrane absorption  
Figure 2: Scattering phenomenon of plane sound waves across an array of cylindrical scatterers. interval or shift the absorption peak towards desired frequencies. Furthermore, the sound absorption changes according to the weight of the masses applied [24; 25; 26; 27; 28; 29]. The limitations of metamaterials applied in acoustics are the rigid geometries that make up the architecture, which can only provide an effective sound attenuator in certain frequency bands [7]. Future applications of metamaterials lie in three-dimensional and four-dimensional systems provided with variable geometries to manipulate electromagnetic fields with different wavelengths [7].
# Optomechanical Analysis and Design of Polygon Mirror-Based Laser Scanners
## 2 Characteristic Functions and Parameters of PMs versus GSs
### Migration Functions  
One can observe, from the expressions of the scanning function, velocity, and acceleration of PMs versus GS in Table 1, the supplemental terms in each PM function. They complicate the discussion, but also offer more degrees-of-freedom in the design process of a PM scanning head, which is an advantage. Thus, in [28,29,32], a novel concept has been introduced, of _migration functions_, transversal \(y(\theta)=(h_{PM}-h_{GS})(\theta)\) and longitudinal/axial \(z(\theta)\). They have, from Figure 2b, Equations (7) and (8), respectively (Table 1). The former represents the coordinate of the incidence point P (of the beam on a PM facet), while the latter represents the coordinate of the axial point A from which it is as if the beam incident on the lens starts. Their graphs are obtained in Figure 4.
## 1 Introduction
Thus, the resource-consuming and complicated circuits used to generate sinusoidal modulation sequences are saved. Secondly, the multipliers for modulation are no longer necessary because multiplying by \(1\) and \(-1\) can be accomplished by just changing the sign of the modulated signal, which means that the number of multipliers is reduced by nearly half. The price is that our method can only deal with the nonlinear mismatch problem in TIADCs where the number of channels \(M\) is the power of two, i.e., \(M=1,2,4,8,...\), while the BWE method is able to calibrate TIADCs with any integer number of channels. Nevertheless, this drawback has limited restriction on the application of our method because the number of channels \(M\) is the power of two in most practical TIADC systems. Although Hadamard sequences (Hadamard transforms) are also exploited to deal with the frequency response problem in \(M\)-TIADCs [32], there are fundamental differences between these two papers. Firstly, the focus of this paper is the nonlinear mismatch problem, while the focus of [32] is the frequency response mismatch problem; secondly, the method proposed in this paper is totally blind, while the method adopted in [32] requires a training sequence. The rest of this paper is organized as follows. In Section 2, the nonlinear mismatch-induced error is analyzed, and a model exploiting the binary Hadamard sequences is proposed. A calibration structure is presented in Section 3 to calibrate the mismatch error based on the model shown in Section 2. The numerical simulation results are presented in Section 4 to demonstrate the performance of our method and the superiorities over existing methods. The concluding remarks are presented in Section 5.
# Exploring Red Wines from the Drama Region: A Chemical, Sensory, and Terroir Insight
## 3 Results and Discussion
### Physicochemical Parameters of Grapes and Wines
The Nevrokopi vineyard, while situated at the highest elevation, presented the higher accumulation of sugar, however, with a significant extension of the ripening period (over one month) and higher total acidity. Longer development times are made possible by the slower ripening process brought on by the cooler climate found at higher elevations. This may produce grapes with balanced acidity and more nuanced flavor profiles [23]. No differences were observed in must acidity among the cultivars and between the growing years for each cultivar. Regarding must pH, Merlot showed a similar value to Agiorgitiko, but lower than Cabernet Sauvignon. Overall, an increase in the must acidity of grapes was concomitant with a decrease in altitude (\(-\)0.456, \(p\) = 0.003), while no correlation was observed in the case of pH. Cooler temperatures at higher-elevation vineyards (e.g., Me-Ne) delay grape ripening and help preserve greater acidity levels [23]. Lower-altitude vineyards led to a higher sugar content and decreased malic acid than those at higher altitudes [30]. Similarly, [PERSON] et al. [31] report that an increase in altitude results in an increase in tittatable acidity, a decrease in pH, and reduced sugar content in the Agiorgitiko cultivar. Accelerated grape ripening, which results in increased sugar levels and reduced acidity, is one of the main problems caused by climate change. This can have an impact on wine balance and ageing potential. According to our research, vineyards in Drama that are located higher retain more acids, which suggests that higher elevations may act as natural buffers against acid loss brought on by temperature. This result is especially important for preserving the balance and freshness of wine in a warmer climate. No significant differences in the YAN values were observed among the three cultivars. In general, in 2023, the YAN values were lower than in 2022 (about 21%); this is valid for each cultivar. Nevertheless, the decrease is 13%, 21.5%, and 30.5% for Merlot, Agiorgitiko, and Cabernet Sauvignon, respectively. It is evident from the high correlation coefficient (0.613, \(p\) = 0.000) that altitude positively affects the YAN. Cooler temperatures at elevated altitudes result in slower grape ripening, which could increase the amount of nitrogen that accumulates in the berries. [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON] [31] showed that temperature and precipitation, in particular, have a major effect on the level of amino acids (a major part of YAN) in grapes. Although there was a general tendency of rising amino acid content with temperature, their study clarified that
## 5 Limitations and Future Research  
This study offers valuable insights and a reliable tool for monitoring collisions in rugby, although it has some limitations. The findings are based on data from a single professional rugby union club, which may not be fully applicable to all clubs or other forms of rugby like rugby sevens or rugby league or to other collision sports. A limitation of this study is that the proposed questionnaire can only be used at the end of a match. Future research could consider designing a questionnaire that includes the perception of collisions during both training and matches to enhance the external consistency and sensitivity of the tool. Another potential limitation of this study is that the questionnaire was not tested and corrected previously, and an analysis of factors that could affect the impact of the questionnaire's application on rugby players was not conducted. Future work could be expanding the study to include a larger cohort, diverse playing styles, and various player positions, which would further enhance the tool's validity and applicability.
## 1 Introduction
[18] investigated the corrosion inhibition of copper in 3.5% NaCl medium by the formation of a film based on ATT and TiO\({}_{2}\) that was applied onto the copper surface via electrodeposition. The obtained results revealed that the fabricated film has an enhanced inhibitive effect on the copper corrosion protection. Furthermore, the inhibition effect of ATT on the corrosion of mild steel in 1 M HCl solution was studied by the group of [PERSON] et al. [19]. They found that ATT acts as a good inhibitor in this acid medium, with the formation of an inhibitive layer consisting of an iron oxide/hydroxide mixture where 5-ATT molecules are encapsulated. In addition, the corrosion protection of mild steel using ATT was also studied by the group of [PERSON] et al. [20]. They found that ATT demonstrated inhibition efficiency for the corrosion of mild steel in acidic solution (0.5M HCl) due to the formation of a film that was adsorbed on the surface of the mild steel. Finally, in our previous studies [21], it was proved that ATT can be considered as a corrosion inhibitor for hot dip galvanized steel by due to the formation of a film between the zinc and the nitrogen or sulfur atoms of the organic compound. The main goal of the presented study is to discern if ATT that contains both sulfur and nitrogen atoms performs as an inhibitor in the aforementioned corrosion process restriction. In this regard, the effect of organic compound is reported, after exposing steel specimens to corrosive environments in its presence. The obtained results are discussed taking into account our previous studies based on the corrosion protection of mild steel [16]. The importance of these experiments is precisely combined with the current urgent requirement for corrosion protection of steel pipelines. On this subject, the protection effectiveness of the complexes, oxides or salts that are created on either mild steel surface, as well as the morphological conversions that occur on the surface of the metal alloy panels following exposure in the presence or absence of inhibitors, are reported based on three families of techniques: electrochemical, microscopy and spectroscopy. The originality and novelty of the present research rests upon the type of corrosion inhibitor studied loaded into hybrid materials and on the corrosion behavior of mild steel in NaCl electrolyte. The inhibitor ATT contains three nitrogen and two sulfur atoms that can act as electron donors; there is a possibility that it is enhanced due to the existence of resonance of the molecule structure. The obtained results are analyzed and discussed in accordance with our previous studies based on the evaluation of several compounds as potential corrosion inhibitors for mild steel. Finally, it may be highlighted that the added value of our work resides in the correlation of the steel corrosion mechanisms with the presence of hybrid materials that utilized as carriers, fabricated though combination of multiple processes and techniques such as sol-gel process, radical polymerization and the coprecipitation method.
# Tutorial Review on Space Manipulators for Space Debris Mitigation
###### Abstract  
Space-based manipulators have traditionally been tasked with robotic on-orbit servicing or assembly functions, but active debris removal has become a more urgent application. We present a much-needed tutorial review of many of the robotics aspects of active debris removal informed by activities in on-orbit servicing. We begin with a cursory review of on-orbit servicing manipulators followed by a short review on the space debris problem. Following brief consideration of the time delay problems in teleoperation, the meat of the paper explores the field of space robotics regarding the kinematics, dynamics and control of manipulators mounted onto spacecraft. The core of the issue concerns the spacecraft mounting which reacts in response to the motion of the manipulator. We favour the implementation of spacecraft attitude stabilisation to ease some of the computational issues that will become critical as increasing level of autonomy are implemented. We review issues concerned with physical manipulation and the problem of multiple arm operations. We conclude that space robotics is well-developed and sufficiently mature to tackling tasks such as active debris removal.  
space manipulators; space robot; active debris removal; freeflyers; robotic grasping +
Footnote †: journal: Robotics
# Machine Reading Comprehension Model Based on Fusion of Mixed Attention
## 2 Problem Formulation and Research Motivation
### Background and Investigation of Machine Reading Comprehension  
#### 2.2.1 Early Research and Development  
The study of machine reading comprehension (MRC) has its origins in information retrieval and text understanding, primarily relying on rule-based methods during its initial stages. For instance, [PERSON] et al. [3] developed the Deep Read system, while [PERSON] and [PERSON] [4] worked on the Quarc system. These systems employed bag-of-words models and heuristic rules to handle the relationships between texts and questions. With the emergence of neural networks, technologies like Recurrent Neural Networks (RNNs), Convolutional Neural Networks (CNNs), and attention mechanisms were introduced to MRC, offering novel approaches for semantically fusing text and question sequences.  
On the one hand, MRC based on deep learning can better capture contextual information and perform significantly better than traditional models; on the other hand, the public availability of large-scale datasets has made it possible to use deep neural network architectures to solve MRC tasks, such as [PERSON] et al.'s large-scale supervised fill in the blank MRC dataset CNN/DailyMail [2], [PERSON] et al.'s famous Stanford question-answering dataset SQuAD [3] in the field of extractive MRC proposed in 2016, and [PERSON] et al.'s real question-answering dataset MSMARCO [12] from the Bing search engine proposed in 2016, which provide a wide range of performance evaluation and testing platforms for MRC systems. The SQuAD dataset has a large scale and high quality of data, making it the mainstream testing benchmark for MRC models. Researchers have proposed many MRC models based on this dataset. With the continuous emergence of new models, the performance of deep neural network-based learning models has exceeded the human average by 91.2% [13].