esa-sceva/satcom-chunk-collection huggingface dataset:
# Automatic Brix Measurement for Watermelon Breeding
## 5 Conclusions  
In this study, we proposed a device to automatically measure the sugar content of watermelons for breeding, including an automatic half-cutting system and a Brix measurement system. In the automatic half-cutting system, the measured values of the watermelon diameters showed a high correlation with the real values, with \(R^{2}~{}=~{}0.9608\) and \(RMSE~{}=~{}4.321\); in the Brix automatic measurement system, the optimal Brix measurement parameters were a lateral gap of 2 mm and a vertical gap of 4 mm, with an average accuracy of 98.74%. This research can provide support for the breeding of elite germplasm of watermelon.  
Figure 7: The accuracies of Brix measurements using different parameters.  
**Author Contributions:** Conceptualization, [PERSON]; data curation, [PERSON]; formal analysis, [PERSON]; funding acquisition, [PERSON] and M.L.; investigation, [PERSON], X.X. and Z.W.; methodology, T.Z., H.H. and Z.W.; project administration, [PERSON] and M.L.; resources, M.L. and S.D.; software, [PERSON]; supervision, M.L.; validation, [PERSON]; visualization, J.H.; writing--original draft, [PERSON]; writing--review and editing, [PERSON], H.H. and M.L. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the National Key Research & Development Program: 2020 YFD 1000303-7; National Watermelon Industry Technology System Project: CARS-25; Key Research & Development Program of Hunan Province: 2021 SK2046; Hunan Agricultural Science & Technology Innovation Program: 2021 CX43; Hunan Agricultural Science & Technology Innovation Program: 2022 CX30; Hunan Agricultural Science & Technology Innovation Program: 2022 CX30; Hunan Agricultural Science & Technology Innovation Program: 2023 CX54; Hunan Modern Agricultural Fruit Industry Program: xcnz [2021] No. 37.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.
# Multi-Output Based Hybrid Integrated Models for Student Performance Prediction
## 4 Experimental Setup  
All data processing, modeling, and analysis in this study were conducted using PyCharm Community Edition 2021.3.2, which was developed by the JetBrain company in the Czech Republic, and Python 3.8. The environment in which these processes were carried out was an Intel(R) Core(TM) i5-8300H processor, which was developed by Intel Corporation in Santa Clara, CA, USA, and had 8 GB of RAM, running on the Windows 10 (64-bit) operating system, which was developed by Microsoft Corporation in Redmond, WA, USA. The data used in this study were obtained from the SLCP. During the data processing phase, the pandas' module was utilized for missing value handling, text discretization, and other processing tasks. Multiple ensemble learning models were called using the scikit-learn module for data modeling, and parameter selection was performed using GridSearchCV. The detailed parameters are shown in Table 1 in Section 3.6. For data analysis and visualization, the matplotlib module was utilized.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Model**} & \multicolumn{3}{c}{**Process Performance**} & \multicolumn{3}{c}{**Process Performance**} \\  & \multicolumn{3}{c}{**Prediction (Method 1)**} & \multicolumn{3}{c}{**Prediction (method 2)**} \\ \hline  & _MSE\_a_ & _MAE\_a_ & _R\({}^{2}\_\)a_ & _MSE\_a_ & _MAE\_a_ & _R\({}^{2}\_\)a_ \\ m\_gdbt & 17.737 & 2.8383 & 0.0167 & 16.769 & 2.7417 & 0.0375 \\ m\_randomforests & 17.674 & 2.8063 & \(-\)0.001 & 17.178 & 2.8562 & 0.0052 \\ r\_gdbt & 18.086 & 2.9610 & \(-\)0.005 & 17.792 & 2.8889 & 0.0050 \\ m\_lgbb & 18.132 & 2.8617 & 0.0058 & 18.037 & 2.8769 & 0.0057 \\ m\_adboost & 18.944 & 2.9401 & \(-\)0.106 & 18.259 & 2.8527 & \(-\)0.073 \\ r\_randomforests & 18.478 & 2.9623 & \(-\)0.011 & 18.489 & 2.9722 & \(-\)0.006 \\ r\_lgbb & 18.903 & 2.9905 & \(-\)0.004 & 18.794 & 2.9871 & \(-\)0.000 \\ r\_adboost & 20.139 & 3.1394 & \(-\)0.124 & 19.707 & 2.9475 & \(-\)0.161 \\ m\_xgboost & 24.787 & 3.3564 & \(-\)0.472 & 22.362 & 3.1556 & \(-\)0.348 \\ r\_xgboost & 24.290 & 3.3235 & \(-\)0.393 & 23.006 & 3.3048 & \(-\)0.407 \\
0\_xgboost & 48.162 & 4.3520 & 0.4434 & 37.588 & 4.0346 & 0.4600 \\
0\_adboost & 47.694 & 3.6535 & 0.4937 & 43.786 & 3.5881 & 0.4735 \\
0\_gdbt & 48.850 & 4.3454 & 0.3914 & 47.318 & 4.1756 & 0.4171 \\
0\_randomforests & 56.879 & 4.3626 & 0.3538 & 49.833 & 4.0620 & 0.4664 \\
0\_lgbb & 79.682 & 5.2129 & 0.1041 & 76.234 & 4.8797 & 0.1409 \\ \hline \hline \end{tabular}
\end{table}
Table 9: Evaluation indicators of method I and method 2.
## 4 Conclusions  
This study investigated the trade-off between thermal comfort ratings and the conditions of legislation and standards for air flow rates through the LAFC. The measurements took place in a clean room laboratory, in a model operating room, with certified equipment. A ComfortSense Dantec device was used to record data and evaluate PMV and PPD indices. Legislation in different countries recommends different discharge velocities through the LAFC, ranging from 0.1 m/s to 0.45 m/s. This research focused on evaluating the thermal comfort during the summer months, when the LAFC is used for cooling, at discharge velocities from 0.15 m/s to 0.25 m/s. The use of speeds up to 0.175 m/s appears to be the most suitable, when the PPD index fluctuates at a value of 20%. At a speed above 0.2 m/s, the PPD index is above 30%. The combination of subcooled air and air speed through the LAFC of 0.25 m/s increased the PPD index up to 70% in the area of the body's center of gravity. In all cases, the velocities in the area of the center of gravity were higher than in the area of the head. The results of this study should provide valuable information for the design and sizing of LAFCs in ORs and other clean rooms. With the help of the choice of a higher LAFC size series, a lower flow rate will be achieved, which will have a favorable effect on the thermal comfort of healthcare workers in the summer months.  
**Author Contributions:** Conceptualization, P.M.; methodology, P.M.; validation, P.M. and D.H.; formal analysis, R.N.; investigation, D.H.; resources, P.H.; data curation, R.N., P.H. and D.H.; writing--original draft preparation, P.M.; writing--review and editing, R.N.; supervision, P.H.; project administration, P.M. and P.H.; funding acquisition, P.M. and P.H. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded under the project of Operational Programme Integrated Infrastructure: Independent research and development of technological kits based on wearable electronics products, as tools for raising hygienic standards in a society exposed to the virus causing the COVID-19 disease, ITMS2014+ code 313011 ASK8. The project is co-funded by the European Regional Development Fund, and project VEGA 1/0633/23--Optimization of the flow preventing the spread of COVID-19 and other viruses and bacteria to the patient.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Data are available in a publicly accessible repository.  
**Conflicts of Interest:** The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results. The authors declare no conflict of interest.
## 2 Measurement Method and Systems
### Scanning Probe  
Figure 4 illustrates the structure of the scanning probe, which is constructed with a quartz tuning fork and a tungsten stylus. Figure 4a,b present the photos of the scanning probe and the tungsten stylus, respectively. The tungsten stylus is made of a tungsten wire with a diameter of 60 \(\upmu\)m through electrochemical polishing. The effective length of the tungsten stylus can reach 150-200 \(\upmu\)m, and the diameter of the stylus tip is about 20-50 nm. The stylus is long and sharp enough to scan the microspheres with diameters of several hundred microns.  
In this study, the diameter of the measured microsphere ranges from tens to hundreds of micrometers. According to the scanning strategy shown in Figure 2, a structural interference may occur between the probe tip and the microsphere when the bottom area is scanned because the surface of the microsphere has a large curvature, especially near the bottom (the lower position of the microsphere in Figure 2). Figure 5 shows the structural interference between the probes and the microsphere. The bottom area of the microsphere is omitted during scanning to avoid the influence of the interference (Figure 5b).  
Figure 4: Photography of a scanning probe and tungsten stylus. (**a**) Photography of a scanning probe; (**b**) Photography of a tungsten stylus.  
Figure 3: Measurement principle of two opposite cross-sectional profiles: (**a**) The measurement of a cross-sectional profile, (**b**) The measurement of the opposite cross-sectional profile after turning 180 degrees.  
The type of the quartz tuning fork in this work is Citizen CFS308. The quality factor (Q-factor) and the first eigenfrequency of the fork are approximately \(10^{4}\) and 32.768 kHz in a vacuum, respectively. When the tungsten stylus is adhered to the fork, the resonant frequency of the probes decreases sharply. A sweeping sine signal is chosen as the excitation signal to confirm the resonant characteristic of probes, the resonant frequency of the probes is about 31.9 kHz, and the Q-factor is about 3000. This Q-factor is still very high, and the quartz tuning fork is extremely sensitive to external force. Therefore, such a high Q-factor ensures that the probe has a high spatial resolution. The experimental results reveal that the spatial resolution of the probe is about 0.4 nm.
## 3 Results
### Effects of Nitrogen Addition on GPP, R, and Ne
#### 3.3.3 The Growing Season Accumulation of Net Crown CO\({}_{2}\) Exchange  
Throughout the growing season, nitrogen addition increased the carbon assimilation (_GPP_) in the saplings but also increased the release rate of crown carbon dioxide (\(R\)) (Figure 7a,b). Compared with the control group, the _GPP_ accumulation increased by 11.56, 51.13, and 54.37% in the low, medium, and high nitrogen treatments (Figure 7a), and the growing season accumulation of \(R\) increased by 14.88, 43.93, and 46.40% (Figure 7b), respectively. Our results provided strong evidence that nitrogen addition enhanced the net crown carbon exchange (\(Ne\)), especially MN and HN treatments, which increased by 52.31 and 55.68% compared with the control, respectively, while the LN was only by 11.01% (Figure 7c).  
Figure 6: Monthly accumulation of net crown CO\({}_{2}\) exchange (\(Ne\), the grey column), crown respiration (\(R\), the black column), and gross primary production (_GPP_, the total length of the grey and black column) after nitrogen addition and the control during the growing season from (**a–d**) June to September. CK, LN, MN and HN represent control (no nitrogen addition), low nitrogen addition (23 kgN\(\cdot\)hm\({}^{-2}\cdot\)a\({}^{-1}\)), medium nitrogen addition (46 kgN\(\cdot\)hm\({}^{-2}\cdot\)a\({}^{-1}\)) and high nitrogen addition (69 kgN\(\cdot\)hm\({}^{-2}\cdot\)a\({}^{-1}\)), respectively. Letters (a, b, or c) suggest significant differences between treatments at \(\alpha=0.05\).
## 2 System Architecture and Assumptions
### OGS-to-Detection Station Fiber Distribution  
In this study, telescope-to-fiber coupling, which enables signal transmission over extended distances through low-loss, single-mode optical fibers to a secure location for detection (which may be in a different location with respect to the receiving telescope), was also modeled. In this way, it was not necessary to upgrade the security of the OGS to a trusted-node configuration, which would have stressed the overall security of the networks. This free-space and fiber-integrated hybrid QKD transmission scenario was recently successfully demonstrated using fiber-connected measurement terminals equipped with SNSPDs [51]. This approach allows not only for the detectors to be safely enclosed in a different room or building, but it also enables multiple users to utilize the same optical telescope. Additionally, fiber coupling may allow for an OGS to be located in favorable locations and outside the urban grid, as well as grant higher altitudes, lower aerosol concentrations, and reduce artificial background noise, while also enabling the extension of the satellite QKD downlink to the urban areas without the need of an intermediate trusted node at the OGS site.
# Channel Measurement and Modeling for 5G Urban Microcellular Scenarios
###### Abstract  
In order to support the development of channel models for higher frequency bands, multiple urban microcellular measurement campaigns have been carried out in Berlin, Germany, at 60 and 10 GHz. In this paper, the collected data is uniformly analyzed with focus on the path loss (PL) and the delay spread (DS). It reveals that the ground reflection has a dominant impact on the fading behavior. For line-of-sight conditions, the PL exponents are close to free space propagation at 60 GHz, but slightly smaller (1.62) for the street canyon at 10 GHz. The DS shows a clear dependence on the scenario (median values between 16 and 38 ns) and a strong distance dependence for the open square and the wide street canyon. The dependence is less distinct for the narrow street canyon with residential buildings. This behavior is consistent with complementary ray tracing simulations, though the simplified model tends to overestimate the DS.  
millimeter-wave propagation; channel sounding; urban micro; 60 GHz channel; 5G channel model; ray tracing +
Footnote †: journal: Sensors
###### Abstract  
Common sound source localization algorithms focus on localizing all the active sources in the environment. While the source identities are generally unknown, retrieving the location of a speaker of interest requires extra effort. This paper addresses the problem of localizing a speaker of interest from a novel perspective by first performing time-frequency selection before localization. The speaker of interest, namely the target speaker, is assumed to be sparsely active in the signal spectra. The target speaker-dominant time-frequency regions are separated by a speaker-aware Long Short-Term Memory (LSTM) neural network, and they are sufficient to determine the Direction of Arrival (DoA) of the target speaker. Speaker-awareness is achieved by utilizing a short target utterance to adapt the hidden layer outputs of the neural network. The instantaneous DoA estimator is based on the probabilistic complex Watson Mixture Model (cWMM), and a weighted maximum likelihood estimation of the model parameters is accordingly derived. Simulative experiments show that the proposed algorithm works well in various noisy conditions and remains robust when the signal-to-noise ratio is low and when a competing speaker exists.  
target speaker localization; Watson mixture model; time-frequency selection; deep neural network +
Footnote †: journal: Medical Imaging
# Self-Organizing and Scalable Routing Protocol (SOSRP) for Underwater Acoustic Sensor Networks
## 2 System Model
### Energy Consumption Model  
The sensor nodes in WSNs are mostly powered through batteries and it is inconvenient to replace it or recharge it when they are depleted. Considering the underwater environment, cost and time required for such operations is high, so energy efficiency is one of the major concerns in designing protocols for UASN. The energy to transmit the data from one node to another over distance is given by Reference [18]:  
\[Et=p_{l}*\Big{(}E_{elec}+E_{amp}\Big{)}+P_{t}*\frac{p_{l}}{R}, \tag{10}\]  
where \(p_{l}\) (bits) is the packet length, \(E_{dec}\) (J/bit) is the electronics energy consumed, \(E_{amp}\) (J/bit) is the amplifier energy dissipation, \(P_{t}\) (W) is the power transmitted, and \(R\) (bps) is the transmission rate. The \(P_{t}\) (W) can be expressed as [18]  
\[P_{t}=A*I_{t}=2\pi r*H*I_{t} \tag{11}\]  
Similarly, the energy consumed (in J) during reception process is given as [19]:  
\[Er=p_{l}*(E_{dec}+E_{DA}), \tag{12}\]  
where \(E_{DA}\) (J) is the energy consumed during data aggregation process.
## 3 Problem Formulation
### Constraints
#### 3.3.2 Security Constraints  
As for each connection port, the voltage deviation should be restricted to a certain range to protect the inner devices and ensure the security operation of the whole system. Therefore, the security constrains can be expressed as:  
\[-7\%\leq\frac{V_{ix}-V_{N}}{V_{N}}\times 100\%\leq+7\%, \tag{28}\]  
According to the security restrictions above, by regulating the voltage of each port, the power transmission on each connection line is determined at the same time.
## 4 Numerical Analysis according to Tunnel Depth
### Analysis Conditions
#### 4.1.2 Blasting Load Calculation  
In order to calculate the blasting load, the formula proposed in [23] was used. The blasting load calculated by the formula in [23] was obtained for the tamping with the charge amount for each charge hole (centre cut hole A: 2.20 kg, centre cut hole B: 2.80 kg, expanded hole: 0.75 kg), and the proposed formula in [24] was used to calculate the equivalent blasting load (P\({}^{\prime}\)). In this study, only the tamping was calculated here to interpret the same as the field conditions. For application as a dynamic load, the time history of vibration generated by blasting must be considered as well. As for the blasting load time history, the hysteresis curve of [24] was mainly used, and the calculated time history curve is shown in Figure 8. In this analysis, the equivalent blasting loads for the charge holes (centre cut hole A, centre cut hole B, and expanded hole) were calculated as 150.58 kg/cm\({}^{2}\), 191.65 kg/cm\({}^{2}\), and 119.78 kg/cm\({}^{2}\), respectively [25]. The actual ground damping is not affected by the vibration frequency, but the damping matrix in the nonlinear analysis performed in the time domain is greatly affected by the frequency [26]. Moreover, according to the study of [27], as the damping increases, the conversion distance increases and the PPV decreases rapidly. Therefore, calculations about frequency and damping ratio are important. In this study, referring to [27], the duration was set as 0.001 s, and the equivalent frequency and ground damping ratio were 830 Hz and 1.0%, respectively. The equation for the blasting load calculation is Equations (1)-(5).  
\[P_{D}=0.000424V_{e}{}^{2}\rho_{e}\Big{(}1-0.543\rho_{e}+0.193\rho_{e}{}^{2} \Big{)} \tag{1}\]  
where \(P_{D}\): Blasting load (kg cm\({}^{-2}\)); \(V_{e}\): Average explosion velocity (m s\({}^{-1}\)); \(\rho_{e}\): Average density (g cm\({}^{-3}\)).  
\[P_{A}=\frac{2\rho_{a}C_{a}}{\rho_{a}C_{a}+\rho_{e}V_{e}}\times P_{D} \tag{2}\]  
where \(\rho_{a}\): Dielectric flux density of sand (g cm\({}^{-2}\)); \(C_{a}\): Propagation velocity of shockwaves (sand) (m s\({}^{-1}\))  
\[P_{B}=\left(\frac{d_{e}}{d_{h}}\right)^{3}\times P_{D} \tag{3}\]  
where \(d_{e}\): Explosive diameter (mm); \(d_{h}\): Borehole (mm)  
\[P^{\prime}=P_{B}\times W\times 2\pi\times\frac{Diameter\ for\ perforation}{Length\ around\ the\ blast\ hole} \tag{4}\]  
where \(W\): Charge per delay (kg)  
\[P(t)=4 Pexp\Big{(}\frac{-Bt}{\sqrt{2}}\Big{)}-\exp(-\sqrt{2}\text{Bt}) \tag{5}\]  
where \(P(t)\): Pressure at time \(t\) (kg cm\({}^{-2}\)); \(B\): Load constant (16,338); \(t\): Arrival time (0.06 \(\mu\)s).
# Erosion Resistance Properties of Iron-Carbon Composite Plating to Molten Lead-Free Solder
## 1 Introduction  
Due to the toxicity of lead to the environment and our health, the EU has enforced directive RoHS and prohibited the use of eutectic Sn-Pb solder (Sn-37 mass%Pb; Sn-37 Pb). It has become common to use Sn-3 mass%Ag-0.5 mass%Cu lead-free solder (SAC305) instead of Sn-37 Pb. As SAC305 has become more common, the erosion of metals in the soldering machine has become a problem. Stainless steel has been used for the flow soldering bath using Sn-37 Pb. When stainless steel is used for the flow soldering bath with SAC305, the damage of stainless steel due to erosion occurs quickly in the bath [1; 2; 3; 4; 5; 6]. The cause is that SAC305 contains a greater percentage of Sn, which now reacts with other metals and has a higher melting point by around 30 K compared to Sn-37 Pb. In the case of SAC305, the erosion of the flow soldering bath has been confirmed by previous studies, and thus countermeasures are taken by surface treatments such as nitriding treatment on the surface of the bath [4; 5]. Meanwhile, regarding erosion in the solder iron tip for hand soldering and in the point soldering machine nozzle, no practical solution has been reached. The erosion of the solder iron tip and the point soldering nozzle are shown in Figure 1. In such damaged parts, currently, the only countermeasure is to replace it with a new one. However, in the replacement method, there are problems in terms of the workability, productivity and the running cost of replacing solder iron tips and soldering machine nozzles.  
Since the solder iron tip and the point soldering nozzle are required to have a constant spread rate of molten solder, Fe is generally used as the material. Therefore, surface treatment by nitriding treatment as used in a flow soldering bath cannot be applied. In this study, two Fe composite plating layers were focused to realize both good wettability of SAC305 and good erosion resistance to SAC305. Graphite and a multi-walled carbon nanotube (MWCNT) [7; 8; 9] were used as filler materials in the composite plating layer. MWCNT is excellent regarding its strength properties, heat conduction properties and abrasion characteristics. Although graphite is inferior to MWCNT in terms of the previously mentioned material properties, it is inexpensive, more widely known and available. We have investigated the erosion-resistance characteristics of the Ni-MWCNT composite plating layer and reported that the amount of erosion of Ni-MWCNT in SAC305 is half that of the Ni plating layer [10]. The purpose of this study is to investigate the wettability of SAC305 to Fe-graphite and Fe-MWCNT composite plating layers and the erosion-resistance characteristics of both layers to SAC305. Moreover, the feasibility of them for use in the solder iron tip and the soldering machine nozzle were examined.
## 4 Experimental Results  
In this section, a series of experiments on TIR ship images with various maritime scenes are performed to validate the accuracy and effectiveness of the proposed small ship target detection algorithm. Furthermore, some classical algorithms and state-of-the-art algorithms are selected for performance comparison.