esa-sceva/satcom-chunk-collection huggingface dataset:
# Analysis of the Possibility of Using Drill-Type Electrodes for Air Ionization
## 1 Introduction  
In the high voltage technique, primary significance lies in the dielectric strength of air in the electrode systems, between which there is an uneven distribution of electric field intensity. The classic electrode systems, between which there is an uneven distribution of the electric field, are spark gap needles--needles with different needle geometries. From the insulation technology point of view, this issue is fully recognized.  
Around the needle electrodes, the electric field intensities are the highest and therefore exhibit partial discharges around them (corona, sparking), which are used in various technological processes and equipment [1; 2; 3; 4; 5]. Examples are electrostatic precipitators for flue gas purification or devices for ozonizing drinking water in water supply networks [6; 7]. In electrostatic precipitators, where there is a strongly uneven distribution of the electric field between the needle electrodes, the moving dust is electrified, captured and precipitated into containers and further processed [8; 9; 10; 11]. In systems for the ozonation of drinking water, for the purpose of improving its biological properties and sanitary parameters, needle spark gaps are used to generate partial discharge and, consequently, to ionize the air and produce ozone to treat the produced drinking water [12; 13; 14]. Ozone processes are also used to reduce the toxicity and destructive environmental impact of municipal and industrial wastewater [15; 16; 17]. This mainly concerns emergencies, such as can be seen in Poland in 2019. In this example, the failure involved the unsealing of Warsaw's main sewer and the entry of approximately 3 million liters of wastewater into the Vistula River. It is in this emergency situation that the technology of ozonation was used to reduce the toxicity of the wastewater discharged into the river.  
In both of the above-mentioned applications, the choice of needle electrodes is crucial for the technological processes, as well as their performance and energy efficiency [18; 19]. The purpose of the research, results of which are presented in this article, was to determine the ionization efficiency of the drill-type needle electrodes. Eleven pairs of drill-type electrodes with diameters ranging from 0.5 mm to 1.5 mm were tested in this respect. The ionization efficiency of these electrodes has beencharacterized by the characteristic voltage values: the initial corona voltage U\({}_{0}\) and the breakdown voltage U\({}_{\rm b}\). In order to determine the electrical strength of systems with such electrodes, which is important for safety reasons, the results of the measurements of breakthrough voltages U\({}_{\rm b}\) in the eleven tested systems were also presented. The obtained results were compared with the corresponding results, characterizing two classic needles--needle electrode systems, of different geometry.
Also, it eliminates the need for instruments and is not affected by aging or environmental changes of observing instruments. That leads to high long-term stability over decades. By comparing the outputs from other sensors (such as radiometers or hyperspectral sounders) with RO, biases and drifts can be corrected. Because there is no need for external or repeated recalibrations, the RO technique is more efficient and cost-effective. Spaceborne GNSS-R remote sensing also provides global coverage and all-weather monitoring. Its low cost and rapid revisit are additional advantages, making it an effective complement to traditional altimetric and scatterometric ocean observations [13]. GNSS-R measurements operate in the L-band (1-2 GHz), where the lower frequency results in less rainfall attenuation, increasing the likelihood of observing the inner core of TCs. Additionally, the smaller size, weight, and power consumption of GNSS-R measurements make them less costly to manufacture and use [14]. The small satellite constellation offers better temporal and spatial sampling than conventional techniques. The real-time and near real-time operational applications require high spatial and temporal sampling rates, such as operational NWP models, and TC monitoring. With great advantages, GNSS-RS data from different satellite missions have been assimilated into different NWP models, where the impact on TC forecasts has been presented by a number of studies. This paper will give a comprehensive review of the method and impacts of assimilating GNSS remote sensing data for TC forecasts. It is organized as follows: Section 2 introduces the GNSS-RS technique, Section 3 reviews the assimilation of GNSS RO data, Section 4 reviews the assimilation of GNSS-R data, and conclusions and prospects are drawn in Section 5.
## 2 Materials and Methods
### Multi-Temporal SPOT5 Pan-Sharpened Surface Reflectance
#### 2.1.3 Pan-Sharpening  
Each SPOT5 image was pan-sharpened to 5 m pixels, as although the panchromatic bands were supplied at 2.5 m resolution, they were acquired using 5 m resolution stereo instruments. The panchromatic bands were first degraded to 5 m and then used to sharpen the 10 m and 20 m bands to create 5 m resolution multi-spectral imagery. The Theil-Sen Estimator, a robust regression  
Figure 2: The method combined automated and manual processing to output the 5 m binary tree cover map and foliage projective cover (FFC) map of New South Wales, Australia. Manual processing steps were assisted by high resolution imagery (0.5–2.5 m).  
technique [45], was used to fit linear relationships on a local, per-pixel basis using all the pixels in a 7 by 7 window based on high-resolution pixels (35 m by 35 m in this case), separately for each band. The method estimated the slope between two sets of points as the median of the slopes between all pairs of points. Using the local relationship, an estimate of the multi-spectral band was computed from the panchromatic band, at the higher resolution.
###### Abstract  
Single-sideband (SSB) modulation through Hilbert transformation has successfully transmitted data using only half the bandwidth of the traditional scheme for the same amount of contained information. Toward this end, the four single-sideband (4-SSB) approach for high order modulation is a promising approach for the next-generation communications by applying soft-input soft-output (SISO) equalizer algorithms over orthogonal frequency division multiplexing (OFDM). However, OFDM is challenging for realizing the feasible 5G communications, compared to the emerging techniques, e.g., non-orthogonal multiple access (NOMA), orthogonal multiple access (OMA) or multiple-input multiple-output (MIMO). Since the 4-SSB is an orthogonal modulation which was successfully applied over the traditional OFDM, in this article, we propose a novel 4-SSB modulation scheme over OFDM Guard Interval (GI) and massive MIMO. Besides the carrier signal, from the receiver side, we also apply the shadow equalizer algorithm in the uncoded and coded environment using turbo codes to achieve the 4-SSB with high efficiency from low complexity and energy consumption for 5G. The evaluation results validate that our system consumes lower energy due to low complexity gained from same number of iterations without the heavy decoding as of the 4-SSB SISO based on the turbo equalizer. In addition, the 4-SSB over the OFDM GI achieves the best performance among the relevant approaches conducted in 4-SSB. The proposal then acts as a practical communication system designed to solve the inter-symbol interference (ISI) induced by additional Hilbert transform in the wireless environment toward fifth generation (5G), given that turbo code is considered as a potential channel coding scheme for 5G radio specification.  
four single-sideband (4-SSB); the guard interval discrete Fourier transform spread orthogonal frequency division multiplexing (GI DFT-s-OFDM); M-ary quadrature modulation amplitude 4-SSB (M-QAM 4-SSB); shadow equalizer; SISO equalizer; massive multiple-input multiple-output (m-MIMO); Hilbert transformation; 5G communications +
Footnote †: _[[https://www.mdpi.com/journal/sensors_](https://www.mdpi.com/journal/sensors_)]([https://www.mdpi.com/journal/sensors_](https://www.mdpi.com/journal/sensors_))
# An Energy-Saving Forwarding Mechanism Based on Clustering for Opportunistic Networks  
[PERSON]  
1 Institute of Computing, Federal University of Amazonas, Manaus 69080-900, Brazil; 1 [EMAIL_ADDRESS] (D.S.); [EMAIL_ADDRESS] (E.M.)1 Institute of Computing, Federal University of Amazonas, Manaus 69080-900, Brazil; 1 [EMAIL_ADDRESS] (D.S.); [EMAIL_ADDRESS] (E.M.)1 Institute of Computing, Federal University of Amazonas, Manaus 69080-900, Brazil; 1 [EMAIL_ADDRESS] (E.  
usage can have different effects on OppNets' performance evaluation. While mobile devices with a fully discharged battery cannot take part in data transmission, those with low battery levels may not be encouraged to cooperate on opportunistic communications [6; 7]. It is well known that data transfer and the discovery of nearby devices consume energy. In addition, after turning a device off, it is not possible to predict when it will be available again, affecting the routing success.  
The battery usage pattern depends on the user's behavior. The work of [PERSON] and [PERSON] [8] examines the problem of energy balance in OppNets from the social structure of the network, considering energy balance with social awareness as an important strategy. We conceived, designed, and implemented a routing protocol that groups nodes according to their battery usage pattern, classifying them by high and low power levels, with forwarding decisions based on devices with similar power levels, considering the high levels.  
The proposed mechanism (\(\epsilon\)GDMI) extends the GPDMI opportunistic routing protocol by [PERSON] et al. [9], taking advantage of its essential characteristics of clustering the nodes around their interests and social-based mobility. That assumption relies on the fact that, in OppNets, nodes tend to cooperate in communication if message content is in their interest [10].  
From the OppNets perspective, these network characteristics are attractive to share interests using mobile devices contacts. This article assumes that the message dissemination considers the interests of the users carrying the mobile devices. Therefore, the proposed mechanism intends to apply a forwarding decision based on the nodes' energy consumption, combining the nodes' social interests over the nodes.  
The idealized routing mechanism creates groups of nodes according to both the energy levels and the similarity of social interests. This combination avoids trying to forward messages through nodes that are considered selfish because of the limited available energy. We present the motivation for this investigation and compare its performance against other routing mechanisms in the literature.  
This paper is organized as follows. Section 2 presents some related works. Section 3 shows our study on energy effects over opportunistic networks. Section 4 describes the architecture overview of the proposed mechanism. Section 5 describes the deployed methodology. Section 6 depicts the performance evaluation results. Finally, Section 7 presents our conclusions and future works.
# An Improved Hilbert-Huang Transform for Vibration-Based Damage Detection of Utility Timber Poles
## 2 Limitation of Original Hilbert Huang Transform:
### Limitation of Hilbert-Huang Transform for Multicomponent and Nonstationary Signals  
In this section, a multicomponent and nonstationary signal is analysed using the original HHT to discuss its limitation. Figure 1 shows a multicomponent nonstationary signal which is sampled at 2000 Hz for 4 s and contains 50 Hz, 100 Hz, and 200 Hz frequency components. Signal's frequency is initially 50 Hz and 100 Hz and increases to 200 Hz after 2 s. Figure 2 depicts the signal's IMFs and the residue obtained through EMD process, whereas Figure 3 demonstrates instantaneous frequencies of those corresponding IMFs produced from HHT. Colour bar in Figure 3 represents instantaneous amplitude of the results. From Figures 2 and 3, it is obvious that IMF1 and IMF2 are the real frequency components that correspond to 200, 100, and 50 Hz, respectively. Moreover, the change in amplitude and frequency from 100 Hz to 200 Hz after 2 s are visible from the Hilbert spectrum plot of IMF1 (Figure 3). Other IMFs in the low frequency region are pseudo-components of the multicomponent signal, which is misleading for the data interpretation.  
Figure 1: A multicomponent nonstationary signal.  
Figure 2: Intrinsic Mode Functions (IMFs) of the multicomponent nonstationary signal.  
This type of phenomenon occurs due to the cubic spline process inherent in EMD. During cubic spline process, large swings occur at both ends of the signal that can propagate inside the signal. As a result, whole signal gets corrupted, and some undesirable IMFs are produced in the low frequency region. Eventually, these undesirable IMFs may provide misleading information regarding the health state of utility timber poles.  
Another shortcoming of HHT is that the first IMF contains a wide range of frequency in the high frequency region in practice [36]. Ideally, IMF should be nearly mono component but in case of IMF1, the mono component property cannot be achieved. Practical signals obtained from field contain more than one frequency at the same time, and IMF will not have one frequency component or narrow range of frequencies. Nevertheless, the instantaneous frequency of IMF1 will be still significant to some extent since IMF1 fulfils the two conditions an IMF should satisfy, and its instantaneous frequency will still be restricted in its own frequency range.
## 5 Conclusions  
This paper evaluates CLM4 FPAR with both remotely sensed FPAR products and flux tower observations. Seasonal cycle, diurnal cycle, long-term trends, and spatial patterns are employed to investigate differences of FPAR between CLM4 and observations. The objective is to offer guidance for future developments in the CLM4 land surface solar radiation partitioning scheme.  
Our findings show that CLM4 simulation and satellite observations are in broad agreement with seasonal cycle, long-term trends, and zonal spatial patterns. These three variables are primarily determined by plant phenology, such as LAI, and therefore should be mostly accredited to the CN module. Some discrepancies still exist. For example, CLM4 has a systematically weaker seasonality; large bias in seasonality was found in certain biome types. We found similar discrepancies between CLM4 LAI and GIMMS LAI3g. Since LAI is the primary input for FPAR calculation, these  
Figure 13: Monthly mean FPAR for the global from 2003 to 2005.  
discrepancies between the model and satellite observations might be addressed through the improvement of LAI parameterization in CLM4.  
Our study highlights the need for treatment of sun angle effect in the FPAR diurnal cycle in CLM. The model currently has plants and bare soil separately allocated into different patches so the plants becomes \"shadowless\": the soil between canopies would never be blocked from solar radiation by the canopy since it is in another patch. Based on the boundary conditions from the Boolean Scene Model, a possible solution for this problem is proposed and illustrated with a two-element model that is simplified from the CLM4 land surface scheme. We also examined reasons for the spatial patterns of peak FPAR months in the Amazon, but tropical rainfall forest could be too dense to be sensitive to the angular effect. In addition, two other possibilities (_i.e._, cloud contamination and higher photosynthesis in dry seasons) could also explain the phenomenon.  
We also note with particular interest that the CLM4 simulations generally reproduced the increasing trend that inferred from the GIMMS3g data sets for both FPAR and LAI, but with smaller significance levels. GIMMS3g data illustrates extensively significant increasing trends in several transitional ecoregions, which indicate influences of forcing factor changes on plant phenology. The model, however, has only limited grids exceeding the 90% significance level though it reproduces the trends over many different areas. A target (_i.e._, climate-vegetation relations) was hence noted for CLM4 future development.  
The study was conducted at The University of Texas at Austin with support from the US Department of Energy (DE-FG02-01 ER63198), and also at Oak Ridge National Laboratory (ORNL). ORNL is managed by UT-BATTELLE for the U.S. Department of Energy under contract DE-AC05-00 OR22725. We thank for inspiring discussions with [PERSON] and [PERSON]. We appreciate the valuable suggestions and feedback from all reviewers.  
The authors declare no conflict of interest.
## 3 Temperature Sensor Clustering Method
### Indicator Construction  
In this subsection, factors that result in the differences between the temperature sensors were discussed. Firstly, it is obvious that the gap between the values of the temperature sensors causes the difference. Take temperature 1 and temperature 2 in Figure 3 as an example; the gap between the value of them is large, so the information of these two sensors are different. As for the physical meaning, a large gap between the values of the two temperature sensors usually means that they are placed at very different places on the machine tool. Thus, the gap between the values of the temperature sensors should be considered in the indicator. However, just considering the gap is not enough. Take temperature 2 and temperature 3 in Figure 3, as an example; there is a large gap between them, however, these two sensors have a proportional relationship, indicating that the similarity between  
\begin{table}
\begin{tabular}{c c c c} \hline
**Sensor No.** & **Sensor Location** & **Sensor No.** & **Sensor Location** \\ \hline
1 & Oil of the guide way of the \(Y\)-axis & 13 & Hydrostatic oil of the guide way of the \(X\)-axis \\
2 & surface of the oil box for gearbox lubrication & 14 & Hydrostatic oil of the spindle \\
3 & Foundation of the machine tool & 15 & Surface of the workable \\
4 & Upper surface on the rear of the ram & 16 & Inlet of the cooling box \\
5 & Cooling water of \(Z\)-axis feed motor & 17 & Front surface of the ram \\
6 & Upper surface of the pillar & 18 & Cooling water of the spindle motor \\
7 & Air near the head stock & 19 & Upper surface on the front of the ram \\
8 & Middle surface of the pillar & 20 & Cooling oil of the gearbox \\
9 & Side surface in the front of the ram & 21 & Near the spindle motor \\
10 & Oil of the gearbox & 22 & Near the hydrostatic oil in the ram \\
11 & Lower surface of the pillar & 23 & Environment temperature near the pillar \\
12 & Surface of the cooling oil tube in the rear of the ram & - & - \\ \hline \end{tabular}
\end{table}
Table 1: Location of temperature sensors.  
Figure 2: Measurement of the thermal error.  
them is high. That is, there is little difference between these two temperature sensors. Moreover, when establishing a thermal error model with sensors that have high similarity, the model shows weak stability and is very easily influenced by disturbance. Therefore, the similarity between the temperature sensors is also needed to be involved in the indicator. In summary, the indicator should contain both the gap between the value of the temperature sensors and their similarity.
## 3 LQ Controller
### Control: Closed Loop System
#### 3.2.1 Tuning of Q and R Matrices and Time Headway  
The results achievable by the feedback control are affected by the choice of the weight matrices \(Q\) and \(R\). In the adopted methodology, they were tuned to guarantee the best trade-off for the following objectives.  
* Comfortable drive: to ensure comfort for each vehicle, threshold values for longitudinal acceleration and jerk are set to \(a_{x}<|2|\frac{m}{g^{2}}\) and \(\frac{da_{x}}{dt}<|0.9|\frac{m}{g^{3}}\), as specified by the authors of [26].
* Safety: the control system must be able to safely stop each vehicle in the platoon, namely avoiding rear-end collisions, when an emergency braking condition occurs at the maximum speed permitted by the regulations, e.g., considering highway speed limits (80 km/h for HDVs).  
A sensitivity analysis on the values of the matrix \(R\) was performed to facilitate the tuning process, aiming at satisfying the aforementioned objectives. The values of the Q matrix are kept fixed during sensitivity. The effect on safety and comfort of the time headway \(t_{h}\) will also be presented. To maximize the overall efficiency of the platoon of vehicles, the time headway is set to maintain the vehicles at low inter-vehicle distances without compromising safety. The matrices were hence tuned by analysing two manoeuvres: WLTP Class 3 driving cycle and emergency braking. In the following sections, the results of a platoon composed of three trucks will be shown.
# Collision Risk Assessment and Operation Assistant Strategy for Teleoperation System
## 7 Conclusions  
This paper proposed a new collision risk assessment model and designed a collision-risk-based operational assistance strategy for teleoperation. The model took into account the effects of relative shortest distance, operation speed, and delay. In addition, a discrete expandable bounding box method was proposed in this paper to make the shortest distance calculation possible. Meanwhile, this paper introduced fuzzy theory into the collision risk assessment model, which can help decision makers in extracting and keeping expert knowledge. Moreover, based on the assessment of the collision risk, three assistant strategies, including partial view highlighting, variation in motion mapping ration, and haptic risk warning, were defined in this paper. The collision risk model and the teleoperation assistance strategies were evaluated experimentally. The experimental results indicate that the discrete expandable bounding box method designed in this paper could accurately obtain the shortest distance, and the proposed fuzzy collision risk assessment  
Figure 23: Time to complete the same task with and without teleoperation-assisted strategies.  
Figure 22: Number of collisions for the same task: (**a**) Without assist strategy; (**b**) with assist strategy. Collision means that the innermost collision bounding box (R0) of the robot arm is detected to have interfered with the obstacle or table at the virtual end.  
model had the correct relationship with the factors to accurately quantify the collision situation. Simultaneously, the designed operation assistance strategy could effectively reduce the risk of robot collision and improve the safety and efficiency of the teleoperation robot for in-orbit assembly.  
The designed assistant strategies in this paper were focused on identifying operational risk and improving the observation of risk points, while the ability to avoid collisions was insufficient. Consequently, in the future, we will continue to improve our teleoperation system, including the study of autonomous obstacle avoidance methods, virtual modeling techniques in non-structural environments to adapt to the complex and changing space environment. Additionally, we will conduct assembly tests in microgravity to explore the effects of microgravity on assembly.  
Conceptualization, S.P., X.C. and P.W.; methodology, S.P. and M.Y.; algorithm, S.P., S.Z. and M.Y.; experiments, S.P., X.G. and M.Y.; research, S.P. and X.C.; writing--original draft preparation, S.P., M.Y. and X.C.; writing--review and editing, X.F., S.P., M.Y., X.C. and P.W.; supervision, X.C. and P.W. 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. 51905530, 51901244, 52005494, 91748209), the advanced research project funded by CNSA (D020303), and the Program 173 of China.  
Not applicable.  
Authors are grateful to [PERSON] for providing us with the camera equipment.  
The authors declare no conflict of interest.