esa-sceva/satcom-chunk-collection huggingface dataset:
# Students' Acceptance and Tracking of a New Container-Based Virtual Laboratory
## 2 Background
### User Acceptance Models  
When integrating new technologies into the learning processes of students (in this case, our CVL in the context of cybersecurity), a set of factors that affect the acceptance of technology arise, such as attitude, social needs, resistance to its use, and so on. Many works can be found in the literature that address this fact considering different contexts [35]. A well-known model for defining and validating the user acceptance of a novel educational technology is the Technology Acceptance Model (TAM) [10; 36]. This model can be used to measure users' attitudes over a new technology, so determining their intention to use it in a particular context [37].  
However, this model does not take into account a diversity of indicators that influence each situation. In this sense, TAM is sometimes updated to fulfill the needs of each specific study.  
On the other hand, there are many research works that apply other models, being one of the most popular the Unified Theory of Acceptance and Use of Technology (UTAUT) [11; 38]. A recent study [39] extends the UTAUT model to determine the indicators that influence the intention to use mobile training from the perspective of consumers: enjoyment, efficacy, satisfaction, confidence, and risk. The authors conclude that their findings fit the UTAUT model for institutions which use mobile learning.  
In [40], the indicators which affect the use of mobile electronic records in the healthcare context are studied and confirmed with both the UTAUT and TAM models. Also, a comparison of TAM and UTAUT is given. A new UTAUT model built with three TAM variables that influence the intention of use of the proposed technology is presented. Those variables are the perceived usefulness (or performance expectancy), the perceived ease of use (or effort expectancy), and the attitude. This new model also makes use of social influence and facilitating conditions.  
Factors that influence students' acceptance are also studied for the proposed virtual laboratory in [30], by concluding the positive impact of employing virtual laboratories for practical activities of cybersecurity. The exploratory study for the students' acceptance is based on the UTAUT model, and it is similar to the initial results shown in this work. The data available in the activity records of the virtual laboratories is also analyzed from the students' interactions with the virtual platform [33], as detailed in Section 4.
# FPGA-Based Manchester Decoder for IEEE 802.15.7 Visible Light Communications
## 4 FPGA Implementation
### Mathematical Noise  
The mathematical processing in the receiver is implemented in fixed-point representation. This representation, very convenient in FPGA, inevitably involves approximations. In addition, the inverse tangent function was further approximated through linear functions. In this section we describe the tests planned to investigate if these approximations impact the performance of the receiver.  
The real mathematics (RM), like implemented in FPGA, was duplicated in MATLAB(r) R2024a. The same test reported in Section 3 was repeated with RM and compared to the reference results obtained with ideal mathematics (IM), i.e., the 64-bit floating point format.  
BERs are reported for \(Z_{\%}\) of 6, 10, 20% in Figure 12, where the dashed and continuous curves describe the results calculated with IM and RM, respectively. In all cases, the curves are very similar. In some parts of the graph, the results obtained with RM seems even better, but this is attributed to statistical fluctuations related to the random nature of the payloads and the noise added into the generation of every signal.  
Figure 11: Phase calculation in FPGA.
## 3 Results and Discussion
### Mechanism Model of Droplet
In this way, the critical vapor velocity (\(U_{\rm V,C}\)) required to entrain the droplet can be obtained when the droplet in the branch outlets is located in \(S_{\rm axial}\), as calculated as in Equations (13)-(15). Figure 10: Forces on droplet in the header. Figure 9: Droplet diameter and the vapor velocity in the branch outlet under various \(\dot{m}_{\rm in}\). \[U_{\rm V,C}=\frac{8\rho_{\rm L}d}{3C_{\rm d}\rho_{\rm V}{\rm{vertical}}^{2}}S_{ \rm{axial}}^{0.5} \tag{13}\]  
\[t_{\rm{vertical}}=\left[\left(d_{\rm B}+\frac{U_{\rm L,H}^{2}}{2a_{\rm{vertical} }}\right)^{0.5}-\frac{U_{\rm L,H}}{\left(2a_{\rm{vertical}}\right)^{0.5}} \right]\left(\frac{2}{a_{\rm{vertical}}}\right)^{0.5} \tag{14}\]  
\[a_{\rm{vertical}}=\frac{3C_{\rm d}\rho_{\rm V}}{4\rho_{\rm L}d}\left(U_{\rm V, H}-U_{\rm L,H}\right)^{2}+\frac{g(\rho_{\rm L}-\rho_{\rm V})}{\rho_{\rm L}} \tag{15}\]  
It can be observed that \(U_{\rm V,C}\) is highly correlated to the velocity of both phases in the header, the vapor velocity in the branch and \(d\)\(U_{\rm V,C}\) at the different axial locations under various \(\dot{m}_{\rm in}\) is plotted in Figure 12. Clearly, the larger \(S_{\rm{axial}}\) requires a higher \(U_{\rm V,C}\) to entrain the droplet and the growth rate of the \(U_{\rm V,C}\) decreases as the \(S_{\rm{axial}}\) increases. Moreover, under the same axial location, for the droplet to be dragged to the branch outlet needs a higher \(U_{\rm V,C}\) when \(\dot{m}_{\rm in}\) is increased. This is mainly due to the smaller \(d\) at higher \(\dot{m}_{\rm in}\), causing the larger acceleration and the shorter flow time \(t_{\rm{vertical}}\) in the vertical direction. It is worth mentioning that in this study, the velocity in the header and the branch outlets are simplified to be averaged from each plane. The distributions of the droplet are assumed to be uniform in the header. Nevertheless, for the actual flow, the distributions of velocity and the volume fraction are non-uniform and extremely complex. In future work,  
Figure 11: Forces on droplet under various \(\dot{m}_{\rm in}\). Figure 12: The critical vapor velocity with and without vortex under various \(\dot{m}_{\rm in}\). the distribution characteristics of these parameters are of great interest to be quantified by a refined the model to improve the model accuracy.
# The Use of Radio and Telemedicine by TMAS Centers in
## 5 Conclusions  
In modern medical care at sea, telemedical assistance is an essential component, allowing for quick and accurate diagnosis, timely treatment, and improved patient outcomes. Although medical assistance at sea has been available for more than 100 years, little research has been carried out on its evaluation. In this study, we examined telemedicine's role in maritime healthcare and examined how it has evolved. Throughout this review, we discussed technological advancements in medical assistance at sea. Since radio medical assistance was introduced in the past, telemedicine has improved the quality of healthcare for seafarers worldwide.  
Despite its current limitations, telemedicine is set to continue improving medical assistance onboard ships in the future. More accurate remote diagnosis and treatment may be possible for doctors and other health professionals with advanced technology. Sophisticated monitoring systems and medical equipment can contribute to achieving this goal. As a result of AI, accurate predictions of illnesses and identification of high-risk patients could be achieved with significant benefits. Research and development investment by government agencies is crucial for improving healthcare service delivery.  
Conceptualization, G.B. and N.C.; methodology, G.B.; PRISMA, G.B.; validation, G.B., N.C. and G.G.; formal analysis, G.B.; investigation, N.C.; resources, G.G.; data curation, G.B.; writing--original draft preparation, G.B.; writing--review and editing, G.B. and F.A.; visualization, N.C.; supervision, F.A.; project administration, F.A.; funding acquisition, F.A. All authors have read and agreed to the published version of the manuscript.  
This work was supported by grant No. 1624/2021 of the ITF Trust, London.  
Not applicable.  
No new data were created or analyzed in this study. Data sharing is not applicable to this article.  
The authors declare no conflict of interest.
# High Performance MRAM with Spin-Transfer-Torque and Voltage-Controlled Magnetic Anisotropy Effects
## 4 Discussion  
The development of MRAM still encounters bottlenecks in dynamic power consumption, energy-delay efficiency and reliability issues. VCMA-MTJ-based MRAM enables designers to have a chance to utilize a controlled electric field (or a voltage) for magnetization switching with efficient non-volatile writing and robust writing process control.  
Compared to STT-MTJ based MRAM, the precessional VCMA mechanism and STT-assisted methods achieve a faster writing speed and lower power consumption. The dynamic writing energy can be reduced to 3.2 fJ/bit, whereas STT-MTJ MRAM has \(\times\)30 larger energy consumption. In particular, the STT-assisted precessional VCMA strategy is less complex compared to precessional VCMA, because an external magnetic field and precise pulse duration control are no longer needed.  
One possible problem about VCMA-MTJ-based MRAM is the source degeneration of the access transistor [25], as the MTJ parallel and antiparallel resistance (100 k\(\Omega\) R\({}_{\text{P}}\) and 200 k\(\Omega\) R\({}_{\text{ap}}\)) is larger than previous STT-MTJ. In precessional VCMA-MRAM, the positive pulse only stresses from bit-line to source-line with the unipolar VCMA effect; therefore, the source degeneration is not dominant. However, in STT-assisted VCMA-MRAM, the bipolar STT current may induce current driving degradation in MRAM access transistor when the current flow from source-line to bit-line.  
Fortunately, after applying the VCMA voltage, the magnetization of MTJ free layer is precessionaly oscillating around the effective field. Only a small driving current can break the equilibrium and switch the magnetization. Therefore, a small current density is provided by the access transistor and source degeneration can be designed with tolerance.  
The reliability of hybrid CMOS/magnetic integration is a major concern for circuit designers in the near future [43; 44; 45; 46; 47; 48; 49]. The integration of unreliable, deep-scaled nanometer CMOS and MTJ processes pose tremendous challenges from the device level up to system level. The design margins to guarantee reliable MRAM write and read operations are no longer sufficient and result in huge circuit overdesign. Our future work will focus on yield and aging performance evaluation of VCMA-MTJ-based MRAM circuits.
# XCO\({}_{2}\) Fusion Algorithm Based on Multi-Source Greenhouse Gas Satellites and CarbonTracker
## 4 Results and Analysis
### Comparison between Multi-Instrument Fused XCO\({}_{2}\) and TC Fusion Dataset  
Multi-instrument fused XCO\({}_{2}\) is derived from the Kriging interpolation fusion of OCO-2 and GOSAT Level 2 products, which take a similar approach as the 10-s average using a variation of Kriging. In order to understand the effect of the TC algorithm in fusing XCO\({}_{2}\) in more detail, this paper compared the difference between multi-instrument fused XCO\({}_{2}\) products and XCO\({}_{2}\) obtained by the TC algorithm, and created a quantitative description. In order to show the differences between the two XCO\({}_{2}\) datasets in different regions, Figure 7 displays positive in red and negative in blue, which can intuitively compare the changes in XCO\({}_{2}\) differences under different seasonal conditions. By comparing the MAE and RMSE between January, April, and October 2018 on a 15-day scale (Table 8), it is found that there is a small difference in January, April, and October, with an RMSE of 0.6736 ppm, 0.7012 ppm, and 0.7395 ppm, respectively, while there is a large difference in July, with an RMSE of 1.1405 ppm. MAE also shows the same characteristics, with a maximum MAE of 0.8143 ppm in July. This feature is particularly obvious in Asia and Europe, and compared with the multi-instrument fused XCO\({}_{2}\) dataset, the XCO\({}_{2}\) obtained by the TC fusion in this paper is higher, which is more obvious in October. In the marine area, there is little difference. Overall, the products obtained in this paper are in good agreement with multi-instrument fused XCO\({}_{2}\). In January, April, July, and October, there are more than 99.41%, 98.34%, 90.97%, and 98.07% areas with differences within \(\pm\)2 ppm.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**TCCON Site** & **TC** & **OCO-2** & **GOSAT** & **CT** \\ \hline PA & 0.927 & 0.8228 & 0.647 & 0.8901 \\ OC & 0.575 & 0.7062 & 0.4657 & 0.5155 \\ IZ & 0.812 & 0.5826 & 0.5951 & 0.7347 \\ BR & 0.907 & 0.8267 & 0.815 & 0.8006 \\ JS & 0.797 & 0.8011 & 0.4588 & 0.8505 \\ WG & 0.939 & 0.8814 & 0.7823 & 0.9414 \\ TK & 0.916 & 0.7852 & 0.7225 & 0.896 \\ DB & 0.750 & 0.6201 & 0.4083 & 0.6211 \\ \hline \end{tabular}
\end{table}
Table 7: \(R^{2}\) of TC Fusion XCO\({}_{2}\), OCO-2 XCO\({}_{2}\), GOSAT XCO\({}_{2}\), and CT XCO\({}_{2}\).  
Figure 7: Comparison of difference between fusion products and multi-instrument fused XCO\({}_{2}\).
_Appl. Sci._**2012**, \(2\), 327-341; doi:10.3390/app2020327  
_Applied sciences_  
**ISSN 2076-3417**  
www.mdpi.com/journal/applsci  
Application of Liquid-Phase Direct Fluorination: Novel Synthetic Methods for a Polyfluorinated Coating Material and a Monomer of a Perfluorinated Polymer Electrolyte Membrane  
**[PERSON] 1,*, [PERSON] 2 and [PERSON] 1**  
Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama 221-8755, Japan; E-Mail: koichi-murata3(@agc.com  
Asahi Glass Co., Ltd., 1-5-1 Marunouchi, Chiyoda-ku, Tokyo 100-8405, Japan; E-Mail: daisuke-sirakawa(@)agc.com  
Author to whom correspondence should be addressed; E-Mail: takashi-okazoe(@)agc.com; Tel.: +81-45-374-7324; Fax: +81-45-374-8848.  
_Received: 13 March 2012; in revised form: 22 March 2012 / Accepted: 26 March 2012 / Published: 10 April 2012_  
A new polyfluorinated anti-staining coating material CF3O(CF2 CF2O)xCF2-CONHCH2 CH2 Si(OCH3)3 has been developed by utilizing the PERFECT method, which employs a liquid-phase direct fluorination reaction with elemental fluorine as a key step. Direct fluorination of a partially-fluorinated ester, which was prepared from a non-fluorinated poly(ethylene glycol) and a perfluorinated acyl fluoride, followed by methanolysis, gave the perfluorinated corresponding compound, which was led to the coating material for surface treating agents, and the methyl ester of the starting perfluorinated acyl fluoride. Application to the synthesis of a new perfluorinated bifunctional sulfonate monomer CF2=CFOCF2 CF2 OCF(CF2 SO2F)2 for polymer electrolyte membranes (PEMs) of fuel cells was also developed.  
direct fluorination; anti-staining coating; surface treating; polymer electrolyte membrane; fuel cell
# Research on the SSUKF Integrated Navigation Algorithm Based on Adaptive Factors
###### Abstract  
In complex environments, the application of traditional Kalman Filtering in GNSS/INS integrated navigation systems often encounters challenges such as filter divergence and accuracy degradation. This paper introduces the technique of Simplified Spherical Unscented Kalman Filtering (SSUKF) and, based on this, proposes an Adaptive Simplified Spherical Unscented Kalman Filtering (ASSUKF) integrated navigation method. This approach, built upon SSUKF, incorporates an adaptive filter that effectively utilizes residuals and innovation sequences to mitigate the divergence phenomenon during the filtering process. Furthermore, the system is capable of online estimation and dynamic adjustment of the statistical characteristics of measurement noise, leading to more accurate state estimation and significantly enhancing the adaptive capability of SSUKF. ASUKF improves position accuracy in the latitude direction by 18.10% and in the longitude direction by 20.6%. For attitude error, ASUKF performs exceptionally well. Specifically, the pitch angle error improves by 27.6% compared to UKF and by 27.1% compared to SSUKF. The roll angle error improves by 29.9% compared to UKF and by 20.1% compared to SSUKF. The heading angle error improves by 24.3% compared to SSUKF, validating the method's substantial advantages in improving system accuracy and robustness, demonstrating its effectiveness and potential in complex environments.  
Simplified Spherical Unscented Kalman Filtering; adaptive factor; integrated navigation; measurement noise +
Footnote †: journal: Applied Sciences
## 3 Verification of Accuracy of FODNOPP
### Example Verifications for Program Accuracy  
#### 3.2.1 Subsonic Single Propeller, Using Code a2  
To validate code a2, the prediction example of the forward flight propeller noise provided by [PERSON] and [PERSON] [11] is selected, in which the experimental and theoretical results for overall noise, encompassing acoustic pressure time histories and spectra, are presented. Separately, [PERSON] and [PERSON] [15] presented theoretical results, including the acoustic pressure time histories and spectra, for the overall noise as well as for its thickness and loading noise components. In this paper, the acoustic pressure time history and spectrum of the overall noise at the observer point \(O_{1}\) (0, 7.28 m, 0) are calculated using code a2. These results are then benchmarked against the experimental data sourced from [PERSON] and [PERSON], as well as the theoretical results provided by [PERSON] and [PERSON] and those by [PERSON] and [PERSON], as depicted in Figure 2. Additionally, the thickness and loading noise results using code a2 are contrasted with those by [PERSON] and [PERSON] in Figure 3. Both Figures 2 and 3 demonstrate that the results of code a2 align well with the experimental data in [11] and the theoretical results in [11; 15]. This substantiates the efficacy of code a2 in accurately predicting the overall noise for the propeller with a subsonic helical tip speed and also in determining its thickness and loading noise components.  
Figure 3: Thickness noise and loading noise of propeller PROP at sea level \(H\) = 0 m, flight Mach number \(M\) = 0.12, at observer point \(O_{1}\) (0, 7.28 m, 0) using code a2, compared with those calculated in [15]: (**a**) Acoustic pressure time histories; (**b**) Spectra (BPF = 107.25 Hz).  
Figure 2: Overall noise of propeller PROP at sea level \(H\) = 0 m, flight Mach number \(M\) = 0.12, at observer point \(O_{1}\) (0, 7.28 m, 0) using code a2, compared with that tested in [11] and calculated in [11; 15]: (**a**) Acoustic pressure time histories; (**b**) Spectra (blade passing frequency BPF = 107.25 Hz).
## 4 Engineering Cases
### Comparative Analysis of One-Off Joining and Conventional Joining Methods
#### 4.2.3 Comparison of Internal Forces and Linear Structures  
Through the method of the dynamic adjustment of counterweights shown in Section 3.2.2, the adverse effect of the cantilever end on the closed section at the helicoidal end can be effectively controlled. Now, we compare the effects of the conventional joining construction and the one-time casting joining construction processes on the structural forces. The changes in the bending moment at the bottom of the pier, the stresses at the top and bottom edges of the main girder, and the deflection under different construction stages of the two conditions are considered, as follows:  
Working condition 1--Conventional closed construction of side spans;  
Work condition 2--Unconventional closed construction.  
1. Side-span closed-construction stage  
We here select the side-pier support section, closed mouth section, side-span \(1/4\) section, side-span \(1/2\) section, side-span \(3/4\) section, and pier top section under stress to perform comparative analyses of the internal force in different sections under the two working conditions, and the differences between linear effects.  
As shown in Figure 19, the trend in stress change at the upper edge of the main girder tends to be the same under one-time joining compared with conventional joining, and the stress value at the lower edge of the main girder is smaller than that at the upper edge, while one-time joining will not produce a tensile stress value. As shown in Figure 20, the trend of the change in the vertical deflection of the main girder is the same in one-time joining as in conventional joining near the mid-span side, and the value of the vertical deflection of the main girder after joining on the side of the side span is a little smaller, which indicates that the method shown in Section 3.2.2 of adjusting the deflection of the cantilever end using weights has an obvious effect.  
2. Bridge Formation Phase  
Usually, in the construction and operation process, the main pier has a tendency to tilt inward towards the center span due to the downward deflection of the main girder. The  
Figure 19: Stress values at the top and bottom edges of the main girder of the side span.  
Figure 20: Variation of displacement in the critical section of the side span.  
large inward displacement of the main pier may lead to tensile stress at the bottom of the pier, and the size of the displacement of the main pier between the one-time casting and the conventional joining process is analyzed in different construction stages. As shown in Figure 21, in the bridge stage, the horizontal displacement of the side piers will be larger under the action of thrust force produced by one-time cast-in-link construction than by conventional lining construction; at the same time, after ten years of operation, its tendency to undergo inward inclination towards the side of the center span is lower. This shows that the one-time cast-in construction is more favorable for the structure than the conventional cast-in construction process.
## 2 Experimental Setup  
The micromachining process of the silicon wafers was carried out using a prototype diode-pumped Yb:KYW fiber laser, generating pulses of 650 fs, i.e., in the sub-picosecond regime. Fiber laser technology has such benefits as high average power and temporal stability. In this prototype design, with a working range of 100-400 kHz, the 200 kHz pulse repetition rate proven to be most efficient and ensured temporal stability of the output power. The laser generates a fundamental wavelength of 1030 nm (3 nm FWHM), second (515 nm), and third (343 nm) harmonic. For this experiment, the 343 nm UV beam was used, where the absorption coefficient of a crystalline silicon is at the maximum level [21]. The laser was operating at 5.5 W (27.5 \(\upmu\)J). According to a previous study [22], two ablation regimes are observed for crystalline silicon in the UV range. The ablation thresholds are 0.54 and 2.4 J/cm\({}^{2}\). The 5.5 W operating power in our experimental setup translates into laser fluence of 3 J/cm\({}^{2}\), which is just above the second ablation threshold. We found that region most suitable to perform micromachining.  
From the laser output, the beam was passing through the optical collimator and focusing system, consisting of mirrors and lenses adequate for the applied laser wavelength. After passing through the optical collimator, the laser beam was directed into the positioning system. To move and focus the UV laser beam on the surface of the workpiece, an optical scanner with a focusing lens was applied. The scanner is equipped with two galvanometric mirrors, that deflect the laser beam, making it possible to move within a given pattern in the XY plane. A telecentric lens was used to focus the beam on the sample surface, as it provides a uniform beam interaction with material in the whole scanning area. The samples were put on the z-axis adjustable table, directly beneath the scanning area, on the exact level of the laser beam focus (Figure 2).  
The presented setup provided a 2-\(\upmu\)m micromachining accuracy and allowed to perform a wide variety of the machining processes: cutting, scribing, engraving, surface structuring, drilling, and dicing