esa-sceva/satcom-chunk-collection huggingface dataset:
# Synthesis of the Energy-Saving Dry Dual Clutch Control Mechanism
## 4 Discussion  
Comparing the proposed DCT with traditional dual-clutch designs, it can be summarized that it has a reduced energy consumption for clutch control. Particularly, in a fairly common dry dual clutch of the automotive industry, each clutch is switched on by a pressure plate and actuator. The drive of such a clutch uses a separate mechanism and actuator (hydraulic cylinder) connected through a distributor to a pump. This requires additional energy costs. Remarkably, energy is permanently spent on maintaining the clutch in the switched-on position. However, there are no shortcomings in the proposed DCT.  
Thus, the considered dry DCT provides fast and practically uninterruptible power flow from the DCT through the clutch. This can improve the vehicle's acceleration dynamics and reduce the energy costs of switching clutches.  
Nevertheless, the kinematic and dynamic analyses of the device [33] showed that the loading of the driven discs for each clutch is uneven. Particularly, clutch margins when switching are different. This impacts the service life of each clutch and dynamic processes in the vehicle's transmission.  
Figure 16: Dependencies of the forces \(Q\) [kh] on the displacement \(S_{k}\) (**a**) and the angle \(\beta\) [deg] (**b**).  
Figure 17: Clutch platter surface profile for equal clutch factors in coordinates \(X_{G}\), \(Y_{G}\) [mm].  
The novelty of the research is in the substantiation of the mathematical model, the development of the methodology, and the related algorithm for choosing the rational design parameters of the DCT and its drive. This increases the functional performance of the unit while reducing energy costs for control.  
The practical significance of the results is to substantiate the possibility of increasing the efficiency of the original DCT. It is also in developing recommendations for determining the rational design parameters and the algorithm's versatility when designing such clutches for automotive, agricultural, and other industries.
# Prediction of Freeway Traffic Breakdown Using Artificial Neural Networks
## 4 Methodology
### Hyperparameter Optimization  
When constructing an ANN model, pre-defined model parameters, also known as hyperparameters, are provided. Hyperparameters are variables such as the number of layers, the number of neurons in the hidden layer, the batch size, and the number of training epochs. The selection of these parameters affects the performance of the ANN model. Therefore, this paper employed the grid search approach to systematically identify hyperparameters that yield optimal performance. Before conducting a grid search, it is necessary to define the hyperparameters. The grid search then utilizes the model with predefined values to explore the model hyperparameters that yield the optimal results through training and evaluation.  
Candidate values of the hyperparameters are shown in Table 2. The horizon timestamp represents the number of time intervals before the occurrence of the breakdown. For example, when the value of the horizon timestamp is 1, the model only selects the traffic conditions from the previous 5 min before the breakdown to predict the probability of event occurrence. When the value is 2, the model will use the information from the previous 10 min.
## 2 Materials and Methods
### Methods  
Principal Component Analysis (PCA) Applied to Environmental and Meteorological Data  
A PCA was applied to evaluate and understand the changes in WUE in the MATOPIBA region. For this, the mean compositions (from 2001 to 2019) of the following variables were used:  
1. LST and WUE (ratio between GPP and ET), based on MODIS orbital products;
2. Rainfall, based on CHIRPS precipitation product;
3. Elevation, Roughness, and Slope of the GMTED and SRTM version 4.1 products;
4. Geographic data, based on Latitude and Longitude.  
The purpose of the PCA is to reduce the number of variables in a dataset to preserve the total variance and identify patterns and/or processes associated with the observed variables [49; 50]. However, before submitting the database to the PCA, it is essential to apply the Kaiser-Meyer-Olkin (KMO) and Measure Sampling Adequacy (MSA) tests [51; 52]. These tests aim to identify the ideal number of principal components (PC). [PERSON]'s method, which selects eigenvalues greater than 1 (\(\lambda>\) 1) [51], was used in this case for this purpose. In addition, the degree of influence of each PC was also verified from their respective factor loading (scores). The KMO and MSA tests are used as indicators of database quality individually and collectively, respectively [49; 50]. They are obtained by Equations (2) and (3).  
\[\text{KMO}=\frac{\left(\sum_{\text{j}}\sum_{\text{k}\
eq\text{j}}\text{r}_{ \text{jk}}^{2}\right)}{\left(\sum_{\text{j}}\sum_{\text{k}\
eq\text{j}}\text{r }_{\text{jk}}^{2}+\sum_{\text{j}}\sum_{\text{k}\
eq\text{j}}\text{p}_{\text{jk} }^{2}\right)} \tag{2}\]  
\[\text{MSA}=\frac{\left(\sum_{\text{k}\
eq\text{j}}\text{r}_{\text{jk}}^{2} \right)}{\left(\sum_{\text{k}\
eq\text{j}}\text{r}_{\text{jk}}^{2}+\sum_{ \text{k}\
eq\text{j}}\text{p}_{\text{jk}}^{2}\right)} \tag{3}\]  
r is the standard correlation coefficient, and p is the standard partial correlation coefficient.  
According to [PERSON] et al. [53], the KMO and MSA tests range from 0 to 1. The values are interpreted as follows: value of the variable or matrix \(<\) 0.5--discarded; between 0.5 and 0.6--bad; between 0.6 and 0.7--reasonable; between 0.7 and 0.8--medium; between 0.8 and 0.9--good; and above 0.9--excellent.
## 2 Related Work
In one study [37], the authors developed a game-theoretic algorithm to solve the optimization problem for overall computing overhead considering various types of computational tasks through computation-offloading decisions, whereas in the other study [38], they optimized the overall cost of the computing overhead according to power consumption and completion time by combining the optimal offloading decision and resource allocation (CPU cycles and power transmission) by MDs. [PERSON] et al. [39] studied task offloading to a MEC server in order to extend resource capacity by hiring resources from cloud computing resources and vehicular nodes in order to minimize the total computing overhead, including latency and monetary cost, of using computer resources. [PERSON] et al. [40] considered a two-tier small cell network comprising a set of relay base stations connected to a set of micro-base stations, where only the micro-base stations are integrated with the MEC servers in order to perform computational tasks from the user. In that study, they used an artificial fish swarm algorithm to optimize the overall energy consumption of the system according to computation-offloading decisions. [PERSON] et al. [41] investigated two levels of offloading decision between two micro-cloud units to achieve high energy efficiency while satisfied with latency. [PERSON] et al. [42] studied computation offloading strategies for the applications in vehicles using edge node considering offloading cost, offloading latency, and load balancing between edge nodes. [PERSON] et al. [17] proposed a hierarchical MEC architecture, with MEC servers arranged according to different processing performances configured by the network operator in order to increase network performance. In that scenario, MDs that request different actions are handled by different levels of MEC servers. A previous study [18] introduced a hybrid wireless network (FiWi) to provide support between cloud computing and MEC but only considered MDs connected to a wireless base station and applied a game-theoretic approach to optimize power consumption by user equipment. [PERSON] et al. [19] optimized IoT power consumption by IoT sensors in a system model that included a MEC server and a remote cloud server by addressing inter-task dependency and the completion time of an IoT service. However, these studies only considered multi-tier architectures that included cloud computing and one MEC. Computation offloading in such multi-tier multi-server architectures is more difficult. In the present study, we considered multi-tier multi-server MEC systems for 5G HetNets and proposed an efficient, low-complexity algorithm to obtain optimal solutions.
## 3 Results and Discussion
### Carcinogenicity of PM10-Bound PAHs
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Recorder** & \multicolumn{2}{c}{**LADD**} & \multicolumn{2}{c}{**Risk Characterised by CSF *} & \multicolumn{2}{c}{**Risk Characterised by IUR b**} \\ \cline{2-9}  & **Roadside** & **Industrial** & **Urban BG** & **Roadside** & **Industrial** & **Urban BG** & **Roadside** & **Industrial** & **Urban BG** \\ \hline \hline \multicolumn{9}{c}{Resident (child)} \\
1 to \(<\)2 years & \(9.4\times 10^{-9}\) & \(1.1\times 10^{-8}\) & \(5.0\times 10^{-9}\) & \(1.0\times 10^{-8}\) & \(1.2\times 10^{-8}\) & \(5.6\times 10^{-9}\) & \(2.2\times 10^{-7}\) & \(2.5\times 10^{-7}\) & \(1.2\times 10^{-7}\) \\
2 to \(>\)3 years & \(1.9\times 10^{-8}\) & \(2.2\times 10^{-8}\) & \(1.0\times 10^{-8}\) & \(2.5\times 10^{-8}\) & \(2.8\times 10^{-8}\) & \(1.3\times 10^{-8}\) & \(2.5\times 10^{-7}\) & \(2.9\times 10^{-7}\) & \(1.3\times 10^{-7}\) \\
3 to \(<\)5 years & \(3.2\times 10^{-8}\) & \(3.7\times 10^{-8}\) & \(1.7\times 10^{-8}\) & \(5.8\times 10^{-8}\) & \(6.6\times 10^{-8}\) & \(3.1\times 10^{-8}\) & \(3.5\times 10^{-7}\) & \(4.0\times 10^{-7}\) & \(1.9\times 10^{-7}\) \\
6 to \(<\)11 years & \(4.1\times 10^{-8}\) & \(4.7\times 10^{-8}\) & \(2.2\times 10^{-8}\) & \(1.1\times 10^{-7}\) & \(1.2\times 10^{-7}\) & \(5.8\times 10^{-8}\) & \(5.1\times 10^{-7}\) & \(5.9\times 10^{-7}\) & \(2.7\times 10^{-7}\) \\
1 to \(<\)16 years & \(4.2\times 10^{-8}\) & \(4.8\times 10^{-8}\) & \(2.3\times 10^{-8}\) & \(1.5\times 10^{-7}\) & \(1.7\times 10^{-7}\) & \(7.9\times 10^{-8}\) & \(6.8\times 10^{-7}\) & \(7.7\times 10^{-7}\) & \(3.6\times 10^{-7}\) \\ Resident (adult) & \(4.5\times 10^{-8}\) & \(5.2\times 10^{-8}\) & \(2.4\times 10^{-8}\) & \(2.9\times 10^{-7}\) & \(3.3\times 10^{-7}\) & \(1.6\times 10^{-7}\) & \(1.3\times 10^{-6}\) & \(1.4\times 10^{-6}\) & \(6.8\times 10^{-7}\) \\ Worker & \(1.3\times 10^{-8}\) & \(1.5\times 10^{-8}\) & \(7.2\times 10^{-9}\) & \(8.7\times 10^{-8}\) & \(1.0\times 10^{-7}\) & \(4.7\times 10^{-8}\) & \(3.0\times 10^{-7}\) & \(3.4\times 10^{-7}\) & \(1.6\times 10^{-7}\) \\ \hline \hline \end{tabular}  
* \({}^{*}\)Concer slope factor of BaF (0.9 per mg \({}^{3}\).4 day\({}^{-1}\).1\({}^{1}\))halation slope factor of BaF (0.011 per mg \({}^{-3}\).3)  
\end{table} 
Table 3: Estimated incremental lifetime cancer risks of PM\({}_{\rm MF}\)-bound PAH exposure characterized by CSF and IUR at the roadside, industrial and urban background sites.
## 4 Discussion
### Benefits and Deficits of Current On-Board Operator Workspaces
#### 4.1.2 Specific HMI Elements  
In the subsequent section, the suitability ratings of each lab's components of the on-board operator HMI will be discussed.  
The HEAT living lab received favorable ratings for the central operating station as well as the peripheral screens for the side mirror video stream. Average ratings were yielded for the front and rear video stream displayed on the central screen.  
In ReallLabHH, operators responded most favorably to the wide-angle camera that transmitted the video stream right in front of the vehicle. Usually not visible without dedicated cameras, this feature might have been perceived as added value to steering a regular, non-automated vehicle. Above-average ratings were also given to the central screen that displayed the shuttle's location accuracy and current route. It was reported to provide a good overview of the ride in a wider area and might therefore positively influence situation awareness. In addition, the key to alternate between automated and manual driving mode was rated as above average. Another input device, the joystick, received average ratings. This is perhaps because it was located on a control box of considerable weight that had to be carried around the on-board operator's neck, applying pressure onand potentially straining the neck and shoulder muscles, with the prospect of chronic pain. A similar rating was given to the touch display for adjusting vehicle settings. As it was located on the right side from the perspective of the operator, next to the door, turning was necessary to operate it. This bears the danger that the operator might divert their eyes away from the road. Below-average ratings were given to the two screens displaying sensor data. Seemingly, the operators' work was not supported significantly by these screens. The lowest suitability rating was given to the trip information provided, implying operators did not find the information about the trip helpful or satisfactory.  
In contrast, on-board operators with TaBuLa found their HMI very suitable for their tasks. All HMI components received the highest ratings possible: the main screen with a map view, control, sensor, speed, and status display, the gaming controller used to steer the vehicle in manual driving mode, and the operating elements on the white box. Only one element received an average rating: the control elements on the black box. This might be due to their small size, which meant that the captions on the buttons were barely legible, negatively affecting usability.
###### Abstract  
The main weakness of the half-bridge modular multilevel converter-based high-voltage direct current (MMC-HVDC) system lies in its immature solution to extremely high current under direct current (DC) line fault. The development of the direct current circuit breaker (DCCB) remains constrained in terms of interruption capacity and operation speed. Therefore, it is essential to limit fault current in the MMC-HVDC system. An enhanced fault current-limiting circuit (EFCLC) is proposed on the basis of fault current study to restrict fault current under DC pole-to-pole fault. Specifically, the EFCLC consists of fault current-limiting inductance \(L_{\textit{FCL}}\) and energy dissipation resistance \(R_{\textit{FCL}}\) in parallel with surge arrestor. \(L_{\textit{FCL}}\) reduces the fault current rising speed, together with arm inductance and smoothing reactor. However, in contrast to arm inductance and smoothing reactor, \(L_{\textit{FCL}}\) will be bypassed via parallel-connected thyristors after blocking converter to prevent the effect on fault interruption speed. \(R_{\textit{FCL}}\) shares the stress on energy absorption device (metal oxide arrester) to facilitate fault interruption. The DCCB requirement in interruption capacity and breaking speed can be satisfied effortlessly through the EFCLC. The working principle and parameter determination of the EFCLC are presented in detail, and its effectiveness is verified by simulation in RT-LAB and MATLAB software platforms.  
fault current-limiting circuit; DC circuit breaker; MMC-HVDC; fault protection +
Footnote †: journal: Applied Sciences
# Future Is Unlicensed: Private 5G Unlicensed Network for Connecting Industries of Future
## 4 Challenges and Research Directions  
LAA has established a solid foundation for bringing LTE to unlicensed bands. Standalone NR-U will open the door to further innovation and novel use cases as we tackle the associated design challenges. A standalone system must satisfy the following primary requirements to be viable for operation in the unlicensed band: First, it must adhere to any applicable regulatory requirements for unlicensed band operation [39; 40], such as limits on transmit power, spectral density, and channel occupancy. Secondly, it must achieve fair coexistence with other nodes of either the same or a different technology, e.g., WiFi. Thus, the realization of standalone NR-U possesses various regulatory and coexistence challenges from the industrial, as well as the technological perspective. Therefore, we categorized the standalone NR-U's research challenge into following sub-subsections with possible research directions.
# Biologically Derived Gels for the Cleaning of Historical and Artistic Metal Heritage
## 4 Organogels for Organic Coatings Removal
### Bio-Based Solvents
#### 4.2.3 Ethyl Lactate  
Lactates are progressively becoming protagonists in numerous industrial sectors as environmentally-benign solvents [99]. They derive from lactic acid, which can be manufactured by renewable technologies engaging biomass as a primary source. Depending on the microorganisms involved, it can be obtained either as pure (R)- or (S)- enantiomer or as a racemate through fermentation of hexoses and other carbohydrates [100].  
Because of the chemical properties and the natural derivation, the lactates family is gaining attention to substitute more hazardous and toxic substances like toluene, xylene, or methyl ethyl ketone (MEK) [101; 102]. Besides the clear green impact on the formulations and syntheses, for which these solvents were normally necessary, the replacement with lactates ensures a dually safer workplace and final goods for the health of operators and end-users [103].  
Among the most employed lactates, besides propyl and butyl, ethyl lactate (ethyl 2-hydroxypropanoate) stands out. It accomplishes many green principles [99]: it is produced by esterification of bio-lactic acid, hence its origin is sustainable and renewable; it has low production cost, low toxicity, and readily biodegradability into water and carbon dioxide [103; 104].  
As a solvent, ethyl lactate appears a reliable alternative due to its low vapor pressure, high boiling point, and ability to dissolve both polar and non-polar species [102; 104]. Thus, its features make it apt for the formulation of industrial dyes, paints, and varnishes [90; 102].  
Appealed by these assets, several research and articles have been published on the potential insertion of ethyl lactate in the broad field of art conservation.  
Compared to other solvents for the preparation of acrylic resins--i.e., Paraloid(r) B72 and B44 -, ethyl lactate is not sufficiently volatile for this purpose [105]. The fact that it remains partially trapped inside the adhesive itself has posed concerns on the potential consequences on the mechanical properties of the film and the treated artifact.  
On the other side, quite a few studies have been carried out on its cleaning efficacy. Its value is proved and recognized in the removal of graffiti inks from underlying original supports [106]. Notably, ethyl lactate demonstrated not only a good solvent strength on graffiti but also a satisfactory selectivity towards specific binders without impacting the subjacent original paint. As a confirmation of its well-noted efficacy, it is reported that ethyl lactate is bulkily sold to companies for the cleaning of graffiti, composites, and analogs [90].  
Similarly, ethyl lactate led to satisfactory removal of natural terpenic varnishes from oil paintings [107]. Remarkably, in this study, the solvent was retained into a bio-derived gel system to face the low volatility of ethyl lactate and mitigate the quantity of possible residues on the treated surface.
## 4 Survey Results
### Publication Venues and Years  
A total of 62 studies were analyzed to assist with answering the questions posited in our research. Figure 3 shows that these studies were published in peer-reviewed journal venues (35 studies, 56.45%) and conferences (27 studies, 43.55%). Overall, the publications appeared in four categories, most notably Computing and Engineering (22 studies, 35.48%) and Information Technology and Education (13 studies, 20.96%) venues. The student performance prediction papers also appeared in the Education (17 studies, 27.41%) and Psychology (8 studies, 12.90%) fields of study, as depicted in Figure 4.  
It can be seen that the number of studies endeavoring to forecast learning outcomes as an indicator of student success is on a constant rise. Figure 5 shows that the interest in student outcomes prediction models was increasing since 2017, which coincides with the global educational shift towards outcome-based assessment and accreditation efforts. Our search of the databases retrieved articles published until the start of November 2020, which might explain the slight decrease in the number of published articles in the year 2020.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & **ACM** & **IEEE Xplore** & **Google Scholar** & **Science Direct** & **Scopus** & **Springer** & **Web of Science** & **Round Total** \\ \hline Round 1 (Initial Results) & 64 & 152 & 65 & 91 & 63 & 115 & 36 & 586 \\ \hline Round 2 (Removing Duplicates) & 64 & 148 & 65 & 91 & 28 & 114 & 33 & 543 \\ \hline Round 3 (Sanning the Title and Abstract) & 12 & 63 & 10 & 13 & 53 & 9 & 27 & 187 \\ \hline Round 4 (Reading Full Text) & 3 & 7 & 5 & 5 & 12 & 2 & 17 & 51 \\ \hline Round 5 (Manual Searches) & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: Search results of several rounds from the electronic bibliographic databases.  
Figure 6 shows that approximately 48.38% (30) of the published predictive models were produced by the efforts of more than three authors. Single authors produced only 8% (5) of the studies.  
Figure 4: Category of publication venues.  
Figure 5: Number of articles distributed per year of publication, from 2010 to November 2020.  
Figure 3: Types of articles reviewed.
# Call Model and Test-Verification Methods for PS-LTE Core Equipment
## 4 Measurement of Wireless Coverage and Quality  
Korea's DSCN project has a strategy to secure the target coverage by (i) establishing fixed base stations for national infrastructure, roads, and densely-populated areas; (ii) utilizing commercial networks for agricultural, fishery, and indoor/underground areas; and (iii) utilizing mobile base stations for mountainous areas. The coverage criteria for national infrastructure and government and public offices are the ground sections of national infrastructure designated according to the Framework Act on the Management of Disaster and Safety. Roads should give priority to service continuity, and in densely populated areas, the coverage range of fixed base stations includes residential, commercial, and industrial areas among the use areas according to the National Land Planning and Utilization Act. A mandatory coverage measurement test should be performed in the field to determine whether a single communications service infrastructure is properly established using four solutions (fixed base stations, commercial networks, mobile base stations, and LTE-based railway wireless communication system (LTE-R)/LTE-based maritime wireless communication (LTE-M)) [21]. Moreover, a quality test for call services should be conducted simultaneously with the coverage measurement. Preliminary testing of call services is required as many risk factors exist in using the newly established DSCNs immediately in various disaster situations. Areas that fall short of the criteria after the test should be retested after the optimization work of the communications business carriers.