esa-sceva/satcom-chunk-collection huggingface dataset:
###### Abstract  
The design of a microwave antenna sustaining a high-energy-content plasma in Electron Cyclotron Resonance Ion Sources (ECRISs) is, under many aspects, similar to the design of a conventional antenna but presenting also peculiarities because of the antenna lying in a cavity filled by an anisotropic plasma. The plasma chamber and microwave injection system design plays a critical role in the development of future ECRISs. In this paper, we present the numerical study of an unconventionally shaped plasma cavity, in which its geometry is inspired by the typical star-shaped ECR plasma, determined by the electrons trajectories as they move under the influence of the plasma-confining magnetic field. The cavity has been designed by using CST Studio Suite with the aim to maximize the on-axis electric field, thus increasing the wave-to-plasma absorption. As a second step, an innovative microwave injection system based on side-coupled slotted waveguides is presented. This new launching scheme allows an uniform power distribution inside the plasma cavity which could lead to an increase of ion source performances in terms of charge states and extracted currents when compared to the conventional axial microwave launch scheme. Finally, the use of both the \"plasma-shaped\" cavity and the microwave side coupled scheme could make the overall setup more compact.  
slotted waveguide antenna; waveguide coupler; wave-plasma coupling; resonant cavity; Electron Cyclotron Resonance Ion Sources (ECRIS) doi:10.3390/telecom2010004
## 2 Materials and Methods  
In this study, the main raw materials had average particle sizes of (1) 0.26 \(\upmu\)m (\"fine\", AKP-30, Sumitomo Chemical, Tokyo, Japan) and (2) 2-4 \(\upmu\)m (\"coarse\", AM-210, Sumitomo Chemical, Tokyo, Japan). The average particle size was 0.3-0.6 \(\upmu\)m for the zirconia powder (Qingdao Terio Corporation, Qingdao, China) to which 3 mol% of yttria was added. A commercial type of polyurethane foam (SKB Tech, Seoul, Korea) with a pore density of 45 PPI (pores per inch) was used as a sacrificial polymer template at a size of 20 mm \(\times\) 20 mm \(\times\) 20 mm. The ZTA slurry consisting of 67 wt. % of alumina, 3 mol% yttria-stabilized zirconia (Qingdao Terio Corporation, Qingdao, China) at 0-40 wt. %, with 1 wt. % Dolapix CE 64 (Zschimmer & Schwarz GmbH Co., Burgstadt, Germany) as a dispersant, 100 mL distilled water, and 10 wt. % polyvinyl alcohol (molecular weight (Mn) approx. 500, Junsei Chemical, Japan) as an organic binder was used to coat the polyurethane foam. An impregnation process was used to coat the mixed ZTA slurry on the polyurethane foam, and the impregnated polyurethane foams were squeezed to remove any excess ZTA slurry. Subsequently, the polyurethane foam coated with the ZTA slurry was dried in an oven, heat-treated at 400 \({}^{\circ}\)C for two hours, and sintered at 1600 \({}^{\circ}\)C for three hours. The ZTA slurry viscosities were measured using a rotary viscometer (ViscoQC 300, Anton Paar GmbH, Graz, Austria), and the compressive strengths of the reticulated porous ZTA specimens after processing at a size of 20 mm \(\times\) 20 mm \(\times\) 20 mm were measured with a tensile tester (RB302 Microload, R&B, Daejeon, Korea). The average particle size distributions were determined by a particle size analyzer (LSTM 13 320 MW, Beckman Coulter, Brea, CA, USA). The microstructures were characterized by means of scanning electron microscope (JSM-6610 LV, Jeol, Tokyo, Japan), and the changes in the pore properties were assessed by means of Mercury porosimetry (AutoPore IV Series, Micro merits, Norcross, GA, USA), using the mercury impregnation method.
# A Blockchain-Based Audit Trail Mechanism: Design and Implementation
## 2 Background and Motivation
### Motivation  
Motivated by the limitations of existing research about Blockchain-based auditing systems identified in Section 2.2, the aim of this research was to go deeper including the particularities of the Blockchain-based implementation for a general-purpose solution, as well as usability aspects. In this sense, a Blockchain monitoring tool is recommended that provides a graphical and web-based interface to access the information recorded in the Blockchain in a user-friendly way, with the Blockchain being fully transparent to users. In this way, users unfamiliar with the underlying technology will also be able to use the auditing system, enhancing the mass adoption of this solution.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Study** & **Main Contribution** & **Main Limitations** \\ \hline \multirow{3}{*}{[31]} & Upgrade of an existing traditional auditing system to improve its security using Blockchain. & Lack of technical aspects specific to the Blockchain technology. \\ \cline{2-3}  & Detailed description of how to use Blockchain for bank accountability. & Limited to banking context (broader applicability limited). Usability is not considered. \\ \cline{2-3}  & Auditing mechanisms based on data recorded in traditional & Availability is at risk (traditional databases). Two systems are required; complexity increases (synchronization is required). \\ \cline{2-3}  & database/InterPlanetary File System (IPFS) systems/secure log systems + tamperproof in Blockchain. & Availability is not considered. \\ \cline{2-3}  & Detailed description of how to use Blockchain for wide area protection systems & Limited application. Usability is not considered. \\ \cline{2-3}  & Detailed description of how to use Bitcoin for secure log management. & enough (Blockchain only saves data but does not execute auditing functions; an additional log server is needed). Usability is not considered. \\ \hline \hline \end{tabular}
\end{table}
Table 1: Blockchain-based audit trail existing approaches (contributions and limitations).  
Taking into account above considerations, the main requirements for the general-purpose Blockchain-based audit trail mechanism proposed in this research that enhances the security and usability of current audit trails solutions are gathered in Table 2.
# Improved Video Anomaly Detection with Dual Generators and Channel Attention
## 4 Experiments and Results
### Ablation Studies  
To verify the effectiveness of the noise generator modules and the second-order channel attention module in DGGAN, we confirm through ablation experiments that these two modules are beneficial to improve the detection accuracy of abnormal video events.  
As shown in Table 1, the AUC results of the anomaly detection model with the noise generator on all of these datasets are higher than the anomaly detection model with only the reconstruction generator. Moreover, the anomaly detection model with a noise generator, including SPCA, is higher than the anomaly detection model with the noise generator only.  
More specifically, the model without the addition of the three modules is taken as the baseline. Only adding the NGA module will improve the three datasets (i.e., Ped1, Ped2, Avenue, the same as below) by +1.9%, +2.4%, and +0.4%, respectively. When only adding the NGB module, the model has been improved by +0.6%, +1.2%, and +2.2%, respectively. When adding both NGA and NGB, the AUC performance of the model improves by +2.6%, +3.3%, and +1.6%. Note that the AUC performance on the Avenue dataset at this time is not as good as adding only the NGB module, but when adding three modules at the same time, the performance of the model has been greatly improved (\(+3.4\%\), \(+4.4\%\) and \(+2.5\%\)). We infer that this is because the combination of NGA and NGB is not completely suitable for all situations, but the combination of these two noise generators and the SOCA module can exert the best effect.  
The experimental results confirm that compared with the video anomaly detection model trained on normal video frames, the model trained by adding pseudo video frames can detect abnormal video events more accurately.
## 3 Proposed System
### Design of Likelihood Functions
#### 3.3.1 Generating a Mixed Normal Distribution  
The RSSI distribution approximates a normal distribution, which allows the Gaussian Mixture Model [34] to be used to generate a mixture normal distribution. The mixture of normal distribution is  
\[f_{mix}(RSSI)=\sum_{0}^{id}\frac{\omega_{mix}^{id}}{\sqrt{2\pi\sigma_{mix}^{id }}}\text{exp}\Bigg{\{}\frac{-\left(RSSI-\mu_{mix}^{id}\right)^{2}}{\sigma_{ mix}^{id}}\Bigg{\}} \tag{6}\]  
where \(\omega_{mix}^{id}\), \(\mu_{mix}^{id}\), and \(\sigma_{mix}^{id}\) are the weight, mean, and variance of the mixture normal distribution generated, respectively. Furthermore, id indicates the ID of the BLE.
# Design of a Compressor Test Rig for Immobilization of the Stall Cell
## 2 Materials and Methods  
### Design Method for the Compressor  
The design dimensions of this test rig are based on a single-stage low-speed axial flow compressor test rig. This experimental setup exhibited typical stall characteristics during the state of instability. A schematic diagram depicting the fundamental structure is presented in Figure 1, while Table 1 provides detailed parameters specific to the compressor. The reference to the single-stage low-speed axial flow compressor primarily pertains to the form of the stall cell (full span with single stall cell) and its size range (circumferential and axial), which helps determine the positioning of measurement points for designing the new test rig.  
The static pressure signal on the compressor wall, collected by four sensors distributed uniformly around its circumference, exhibits temporal variations when the compressor enters the stall. Figure 2 illustrates that the pressure disturbances of these four sensors are also out of phase by a quarter period, indicating the presence of a single stall cell throughout the entire stall process in the compressor. As the flow decreases, there is a gradual increase in the amplitude of pressure disturbances. Furthermore, even after complete stalling occurs, the speed of this stall cluster remains at approximately 37.5% of the rotor speed.  
Based on the results depicted in Figure 2, with respect to the stall cell coordinate system, the rotor's rotational speed is 62.5% (a reduction of 37.5%) while rotating in one direction, whereas the stator rotates at a speed of 37.5% but in the opposite direction. Consequently, for the proposed counter-rotating compressor, a rotational speed ratio of 62.5:37.5 or 5:3 is designed accordingly. As a result, the first rotor operates at a speed of 1500 r/min, and the second rotor at 900 r/min. The concept of transforming from a single-stage compressor to a counter-rotating compressor is illustrated in Figure 3.  
However, the experiment revealed that the stall cell exhibited continuous rotation at this speed ratio. After conducting replicate tests, an optimal rotation speed ratio of 1.1 was determined for the two rotors, with the first row rotating at a speed of 1100r/min and the second row at 1000 r/min. A detailed account of the specific testing process will be provided in the section detailing compressor characteristics and stall cell immobilization.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Outer diameter/mm & 500 \\ Hub ratio & 0.75 \\ Design speed/r/min & 2400 \\ Blade number of the rotor & 60 \\ Blade number of the stator & 60 \\ Rotor tip clearance/mm & 0.5 \\ Stator tip clearance/mm & 0.3 \\ Design flow coefficient & 0.6 \\ \hline \hline \end{tabular}
\end{table}
Table 1: The main parameters of low-speed axial compressor.  
Figure 1: Schematic layout of a low-speed axial compressor.
# A Hybrid RF/FSO Transmission System Based on a Shared Transmitter
## 3 Experimental Setup
The signal is then amplified by an electrical amplifier (model AT-LNA-0043-3504 from AT Microwave, gain of 35 dB) and captured by a 100 GSa/s oscilloscope (model DSA71604, Tektronix, Beaverton, OR, USA) for subsequent offline digital signal processing (DSP). The offline DSP of the RF signal includes digital down-conversion, CMA, FOE, CPE, and DD-LMS.
## 7 Example of Using CPM to Determine the Resistance of a Continuous I-Beam
### Welded Section
#### 7.2.4 Design Ultimate Resistance
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Wall Thickness (mm)** & **t=** & **8** & **7** & **6** & **5** \\ \hline Slenderness & \(\lambda\)=b/t= & 15.63 & 17.86 & 20.83 & 25.00 \\  & for \(l_{p}\): \(M_{eff}^{CP}\)= & 244.81 & 201.32 & 159.99 & 121.57 \\ Design ultimate resistance (kNm) & for \(l_{s}\): \(M_{eff}^{CP}\)= & 245.78 & 210.24 & 167.37 & 127.27 \\  & \(M_{c,Rd}^{EC3}\)= & 208.72 & 170.89 & 135.56 & 103.16 \\ Ultimate load acc. CPM (kN/m) & for \(l_{p}\): \(q_{eff,p}^{CP}\)= & 196.41 & 161.52 & 128.36 & 97.54 \\  & for \(l_{s}\): \(q_{eff,s}^{CP}\)= & 145.93 & 124.83 & 99.38 & 75.57 \\ Ultimate load acc. EC3 (kN/m) & for \(l_{s}\): \(q_{eff}^{EC3}\)= & 123.93 & 101.47 & 80.49 & 61.25 \\ Percentage increase of resistance (\%) & \(q_{eff}^{CP}/q_{eff}^{EC3}\)= & 17.76 & 23.02 & 23.46 & 23.37 \\ \hline \end{tabular}
\end{table} 
Table 3: Summary of ultimate resistance results according to CPM and EC3 for the I-300\(\times\)t\(\times\)250\(\times\)t section and four wall thickness variants.
## 2 Scheme of Multiple-Access Time and Frequency Transfer
\[\boldsymbol{\varphi}_{\rm AC}=\boldsymbol{\tau}_{\rm TC}+\boldsymbol{\tau}_{ \rm CA}+\boldsymbol{\tau}_{\rm RA}+\Delta\boldsymbol{\varphi}_{\rm AC} \tag{4}\]  
\[\boldsymbol{\varphi}_{\rm CA}=\boldsymbol{\tau}_{\rm TA}+\boldsymbol{\tau}_{ \rm AC}+\boldsymbol{\tau}_{\rm RC}-\Delta\boldsymbol{\varphi}_{\rm AC} \tag{5}\]  
Figure 2: Timing diagram of the multiple-access time and frequency transfer for one master site A and two slave sites B and C.  
Based on Equations (4) and (5), the relative phase difference between sites A and B can be calculated by  
\[\Delta\mathbf{\varphi}_{\mathrm{AC}}=\frac{\mathbf{1}}{2}[(\mathbf{\varphi}_{\mathrm{AC}}- \mathbf{\varphi}_{\mathrm{CA}})-(\tau_{\mathrm{CA}}-\tau_{\mathrm{AC}})-(\mathbf{\tau}_{ \mathrm{TC}}-\mathbf{\tau}_{\mathrm{RC}})-(\mathbf{\tau}_{\mathrm{RA}}-\tau_{\mathrm{TA} })] \tag{6}\]  
where \(\varphi_{\mathrm{AC}}\) and \(\varphi_{\mathrm{CA}}\) can be measured by a phase discriminator. \(\tau_{\mathrm{AC}}\) and \(\tau_{\mathrm{CA}}\) are identical as the two-way links are reciprocal. The other two fixed terms, (\(\tau_{\mathrm{TC}}-\tau_{\mathrm{RC}}\)) and (\(\tau_{\mathrm{RA}}-\tau_{\mathrm{TA}}\)), can be calibrated by a high-precision counter. Finally, \(\Delta\varphi_{\mathrm{AC}}\) can be calculated to determine the real timing difference between sites A and C. In this paper, Figure 1 only shows the case of two slave sites, and the schematic diagram can be easily extended to the scenario of N slave sites. The number of slave sites N is mainly constrained by the following parameters, including the repetition rate of femtosecond lasers and the bandwidth of photodetectors. In this experiment, the repetition frequency of the laser is 100 MHz, and the bandwidth of the photodetector is 10 GHz; the theoretical number of slave sites supported by this system is 100. To increase the number of slave sites, it is possible to consider reducing the repetition frequency of the laser and increasing the bandwidth of the photodetector. Of course, the parameters in practical application still need to be considered based on the actual number of slave sites.
## 3 Results and Discussions
### SEM-EDS Sample Surface Analysis
#### 3.2.2 Coating Thickness  
Coating thickness measurements were performed in cross-section by scanning electron microscopy (SEM) at 300\(\times\) magnification in 5 different areas. A representative example for each sample is shown in Figure 8.  
The obtained mean values are summarized in Table 5.  
Figure 8: Overall coatings (**left**) and barrier layer (**right**) thickness of AZ63_5m (**a**), AZ63_10m (**b**), and AZ63_20m (**c**) samples.  
Figure 8 and Table 5 show that PEO coatings are non-uniform, being thinner in the growth areas above the \(\beta\)-phase (concave regions) and thicker in the areas corresponding to coating formation from the \(\alpha\)-Mg matrix. This also explains the high values of mean thickness standard deviations. The barrier layer thickness increased with processing time from a mean value of 0.36 \(\upmu\)m for the 5 min PEO treatment, to approx. 0.66 \(\upmu\)m for the 10- and 20-min processing times.
# Economic Loss of Pine Wood Nematode Disease in Mainland China from 1998 to 2017
###### Abstract  
The occurrence and prevalence of pine wood nematode disease has had a great impact on China's forestry production and ecological environment, but the quantitative evaluation of the economic losses of this biological disease is lacking from a macro-geographic scale and long-term series perspective. This study establishes a pine wood nematode disease economic loss evaluation index system, covering the loss of natural ecology, landscape aesthetics and economic production, and quantitatively evaluates the economic losses of pine wood nematode disease in mainland China at a provincial level from 1998 to 2017. The results show that the economic losses of the pine wood nematode disease in China showed a fluctuant rising trend from 1998, since 2013, it has entered a full-scale outbreak phase, and since 2015, the economic loss has increased significantly, with a growth rate higher than 40%. The average annual total economic loss is CNY 7.17 billion, of which the direct economic losses is CNY 1.53 billion, and the indirect economic losses is CNY 5.64 billion. The loss of forest material resources, the expenditure of ineffective forest management expenditure and prevention and control expenditure were CNY 817 million, CNY 649 million, and CNY 67 million, respectively. Regulate service value loss, support service value loss and cultural service loss are CNY 3.95 billion, CNY 1.41 billion, CNY 276 million, respectively. East China and South China suffered the most due to pine wood nematode disease, and the economic loss of these regions accounted for 79.9% of the total national economic losses. Among them, Zhejiang Province, Guangdong Province and Jiangsu Province lost CNY 2.14 billion, CNY 1.81 billion, and CNY 1.22 billion, respectively, accounting for 26.8%, 22.7% and 15.3% of the total national economic loss.  
Keywords:pine wood nematode disease; economic loss; evaluation index; China; provincial scale +
Footnote †: journal:
###### Abstract
Though these methods detect vocal fry or creaky segments, they do not allow a detailed study of voice production. Previous studies have tried to interlink vocal fold vibration patterns with voice quality types. Several studies have investigated the vibration patterns of vocal fry, which include the number of opening and closing phases of the vocal folds in a single modulator cycle, and the duration of the closed phase. The authors of [17] and [18] found single- and double-pulsed patterns, respectively, using high-speed videos, where the closed phase is longer than the open phase. More evidence for the existence of multiple pulses in a single cycle was reported in [1,2,5]. Furthermore, multiple pulses in a single cycle without a long closed phase were observed using electroglottograms which reflect translaryngeal electrical resistance that is proportional to the contact area of the vocal folds [19]. In this paper, we observe vocal fry GAWs with multiple single-peak pulses in a single cycle. A GAW is the time series of the glottal area, i.e., the projected area of the space between the vocal folds, which vibrate during phonation. In the open phase, the magnitude of the GAW monotonically increases and decreases while the vocal folds are opening and closing, respectively. The magnitude becomes zero when the folds are closed completely, i.e., during the closed phase. The pulses are amplitude modulated and no long closed phase is observed. Throughout the paper, we refer to single-peak pulses. We model the GAWs using an analysis-by-synthesis approach. A modified version of the analysis-by-synthesis approach implemented in [20] for modelling diplophonic GAWs is used. Here, we use two supporting points per pulse of GAW instead of one while modelling the input GAWs. This helps in improving the estimation of the upper and lower envelopes,--discussed in Section 2.4. Furthermore, instead of two fundamental frequencies, one fundamental frequency is used for modelling GAWs. In this study, GAWs are used to distinguish between vocal fry and normal voice quality. The remainder of this article is structured as follows. In Section 2, the extraction of GAWs, the different types of observed amplitude modulated GAWs, and the modelling of GAWs using analysis-by-synthesis are described. The results of automatic classification of amplitude modulated vocal fry GAWs and euphonic GAWs are reported in Section 3. Section 4 discusses the performance, limitations and the possible future works of this study. Finally, Section 5 concludes the paper.
# A Meta-Analysis on Dual Protocols for Chronic Stroke Motor Recovery: Robotic Training and tDCS
## 3 Results
### Lower Limb Motor Functions: Short-Term Effects  
A random-effects model meta-analysis on the five comparisons from five studies revealed significant positive short-term effects of combined tDCS and robotic training protocols on lower limb recovery post-stroke: \(SMD=0.693\); \(SE=0.237\); variance = 0.056; 95% CI = 0.228-1.157; \(Z=2.924\); \(p=0.003\); (see Figure 4). These findings included a relatively small degree of heterogeneity: (a) \(Q\)-value = 4.789 with \(p=0.310\) and (b) \(I^{2}=16.472\)%. Moreover, the publication bias assessments indicated minimal levels of asymmetry for the individual effect sizes: (a) a revised funnel plot with two imputed values after conducting the trim and fill technique (Figure S3) and (b) [PERSON]'s regression test: \(\beta_{0}=3.625\) and \(p=0.130\). Importantly, these findings revealed that the combined robot-assisted movements and tDCS protocols significantly improved the motor capabilities of the lower extremities post-stroke.  
Figure 4: Short-term effects of robotic training combined with tDCS on motor function in the lower extremities. The synthesized data derived from a random-effects model show significant positive transient effects after lower motor rehabilitation. Note that the red diamond indicates overall effect size and squares denote individual effect sizes with 95% CI. More positive values indicate more treatment effects after the combined protocols [37, 47, 53, 57, 64].  
Figure 3: Long-term effects of robotic training combined with tDCS on upper limb function. The synthesized data derived from a random-effects model show no significant positive sustained effects on upper motor rehabilitation. Note that the red diamond indicates overall effect size and squares denote individual effect sizes with 95% CI. More positive values indicate more treatment effects after the combined protocols [45, 46, 51, 52, 56, 59, 60, 61, 66].
# Research on a Measurement Method for the Ocean Wave Field Based on Stereo Vision
## 2 Materials and Methods  
### Stereo Calibration  
The purpose of calibration is to obtain a mapping model between the target that is in three-dimensional coordinate space and the two-dimensional image [22]. Essentially, the internal parameters, external parameters, and distortion coefficients that are obtained through this calibration are the basis of the image correction, parameter inversion, and three-dimensional reconstruction. This paper refers to the method that was proposed by [PERSON] [23] in order to achieve dual-objective targeting. The specific steps are listed as follows:  
1. Construct a checkerboard calibration board with black and white grids, wherein the length and size of the black and white grids are 10 cm and 9 cm \(\times\) 7 cm, respectively.
2. Use the binocular camera to take 25 images of the calibration board from different angles.
3. Use the algorithm to identify the pixel coordinates of the corner points (i.e., the black and white grid intersections) in the image for matching.
4. Calculate the inversion in order to obtain the internal parameters, external parameters, and lens distortion coefficients of the binocular camera.