esa-sceva/satcom-chunk-collection huggingface dataset:
# Fuzzy-Based Multi-Modal Query-Forwarding in Mini-Datacenters
## 7 Conclusions  
In this paper, we presented a novel mini-datacenter architecture in the form of wireless sensor networks to efficiently manage query-based data collection from IIoT devices. The proposed system addressed the challenges of query forwarding under resource-constrained, fluctuating query traffic by incorporating a layered architecture, a query-flow management framework, and a multi-modal query forwarding approach. A command center, a set of gateways, and a set of IoT sensors formed the layered mini-datacenter architecture, where redundant query forwarding through multiple fitted gateways resulted in reliable transmission. Two forwarding techniques, such as coarse-grain and fine-grain, were proposed and developed for query transmission. Fuzzy-based intelligence was integrated within the developed framework, which facilitated dynamic selection between the two granularities, adapting to varying network conditions, ensuring a balance between reliability and congestion control. We tested the proposed framework with 10 to 100 gateway nodes to evaluate its scalability and robustness in complex environments, and the results show adaptive buffer usage while maintaining over 95% transmission reliability.  
S.J.H.: conceptualization, methodology, software, validation, and writing. P.N.M.: conceptualization, methodology, software, validation, and writing. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by Kuwait University, grant number EO04/23.  
Figure 15: Reliability against gateways count with 95% confidence interval.  
Data Availability Statement: The raw data supporting the conclusions of this article will be made available by the authors on request.  
This research work was supported and funded by the Research Sector, Kuwait University, Research Project no. EO04/23.  
The authors declare no conflicts of interest.
# Orientation and Exposure Efficiency of a Solar Tracking Surface in Clear Sky
## 1 Introduction
Active solar trackers follow continuously the position of the sun during the day, using sensors [14]. When the sensor detects change in the solar radiation, it will trigger the motor or actuator to move the position of the panel. Depending on their movement technique, these types of trackers can be further categorized into single-axis or double-axis systems [15]. Although this tracking strategy is much more efficient in terms of solar energy capture, the need to use expensive devices makes it less economic and thus less common. A chronological solar tracking system is based on the times of the changing position of the sun. A solar panel is moved at a fixed speed and angle during the day [16]. This method of sun tracking is relatively efficient energetically, because there is not too big a tracking error and, thus, low energy losses. Several algorithms for this tracking method have been developed, based also on astronomical equations [17; 18; 19]. There is still need for improvement in solar tracking performance while maintaining availability and low cost. This article solves the problem of optimizing the use of direct solar flux in terms of solar tracking technology performance. A novelty in the article is the presentation of criteria for assessing the effectiveness of the sun tracking system with the help of orientation and exposure, displaying the basic laws of nature.
## Mechanism of Thin Layers Graphite Formation  
by \({}^{13}\)C Implantation and Annealing  
**[PERSON], [PERSON] *, [PERSON], [PERSON], [PERSON] and [PERSON]**  
ICube-Laboratoire des Sciences de l'Ingenieur, de l'Informatique et de l'Imagerie,  
Universite de Strasbourg-CNRS, 23, rue du Loess, Strasbourg Cedex 67037, France;  
E-Mails: [PERSON] (G.G.); [EMAIL_ADDRESS] (F.A.);  
[EMAIL_ADDRESS] (D.M.); [PERSON] (C.S[PERSON]);  
[EMAIL_ADDRESS] (F.A.)  
* Author to whom correspondence should be addressed; E-Mail: [EMAIL_ADDRESS];  
Tel.: +33-3-88-10-6546; Fax: +33-3-88-10-6548.  
_Received: 31 December 2013; in revised form: 5 March 2014 / Accepted: 18 March 2014 / Published: 21 April 2014_  
**Abstract:** The mechanism of thin layers graphite (TLG) synthesis on a polycrystalline nickel film deposited on SiO\({}_{2}\) (300 nm thick)/Si(100) has been investigated by \({}^{13}\)C implantation of four equivalent graphene monolayers and annealing at moderate temperatures (450-600 \({}^{\circ}\)C). During this process, the implanted \({}^{13}\)C segregates to the surface. Nuclear Reaction Analyses (NRA) are used for the first time in the topic of graphene synthesis to separate the isotopes and to determine the \({}^{12}\)C and \({}^{13}\)C concentrations at each step. Indeed, a significant part of carbon in the TLG also comes from residual \({}^{12}\)C carbon absorbed into the metallic matrix. Raman spectroscopy and imaging are used to determine the main location of each carbon isotope in the TLG. The Raman mappings especially emphasize the role of \({}^{12}\)C previously present at the surface that first diffuses along grain boundaries. They play the role of nucleation precursors. Around them the implanted \({}^{13}\)C or a mixture of bulk \({}^{12}\)C-\({}^{13}\)C aggregate and further precipitate into graphene-like fragments. Graphenization is effective at around 600 \({}^{\circ}\)C. These results point out the importance of controlling carbon incorporation, as well as the importance of preparing a uniform nickel surface, in order to avoid heterogeneous nucleation.  
**Keywords:** carbon; graphene; thin layers graphite; nickel; nuclear reaction analysis; Raman spectroscopy; Raman imaging; nucleation; \({}^{13}\)C isotope +
Footnote †: journal: Journal of Physics A
# An Effective Water Body Extraction Method with New Water Index for Sentinel-2 Imagery
## 3 Methods
### The Contrast Value between Water Bodies and Nonwater Bodies  
The purpose of the water index is to enhance the brightness value of water and to suppress nonwater brightness values. By comparing the mean value of the index values in water and nonwater bodies, the ability of the NDWI and SWI to distinguish water bodies from the nonwater areas can be evaluated. The greater the difference of mean value between water and nonwater bodies, the more easily the water body is extracted. Thus, the effectiveness of a water index can be evaluated by comparing the mean value difference between water and nonwater bodies [15]. The formula of the contrast value (\(CV\)) is as follows.  
\[CV=E-K \tag{13}\]  
In this case, \(E\) denotes the mean value of NDWI or SWI in terms of the water body and \(K\) denotes the mean value of NDWI or SWI in terms of the nonwater body.
# Power Prediction of Bifacial Si PV Module with Different Reflection Conditions on Rooftop
## 3 Proof of Theoretical Approach  
### Experimental Preparation  
Experiments were conducted outdoors to verify the accuracy of the proposed modeling. All the suggested coefficients of the tilt angles, time, latitude, and solar time of the day of measurement were obtained and the rear side irradiance was predicted. After calculating the outputs from the rear and front sides, the error was measured to compare the sum of the predicted outputs of both sides with the in-situ output power measured by the I-V measuring device. To investigate the effect of irradiance on the rear side, four different environments with different albedo values were created. The 58-cell modules were manufactured for the test using a bifacial solar cell fabricated using commercial fabrication line. Under Standard Test Condition (_STC_), the maximum power of the front side is 262.3 W, the power of the rear side is 217 W, and the efficiency is measured as 16.2%.  
Figure 5 is the module used in Experiments 1-4. Figure 6 shows the test data of the modules obtained from the official test report. Table 1 shows the environmental albedo of the rear environment, the environmental condition of the floor, and the amount of output on  
The experimental site is the rooftop of a four-story building located at 37.54\({}^{\circ}\) latitude and 127.08\({}^{\circ}\) longitude with different backside reflection conditions, as shown in Figure 7. Therefore, it is confirmed that the value of \(\varnothing\) was set to 37.54\({}^{\circ}\). The module was installed at 30\({}^{\circ}\). The \(d_{n}\), \(\delta\), and \(\varepsilon\) values could be obtained from the date of the experimental data. The data were obtained using the latitude of the test site of the module installed in the southeast direction as the parameters for obtaining the GHI on d\({}_{n}\)th day, and the exact time and date obtained from the experimental data. A solar irradiation meter was installed for measuring the actual irradiation. However, it was installed on the upper part to minimize the influence of the shadow on the module. The rear environment area is constructed considering the shadow formed by the irradiance.  
The conditions of the experimental environment were \(\varepsilon\) [\({}^{\circ}\)] = 0.994, \(\delta\) [\({}^{\circ}\)] = 8.294, \(\varnothing\) [\({}^{\circ}\)] = 37.54, and \(cos\theta_{ZS}\) [\({}^{\circ}\)] = 29.47.  
Figure 8: Site and environment for experiment on the ground.  
Figure 7: Site and environment of Experiments 1–4.
## 4 Experiments and Analysis  
To validate the effectiveness of GMN+, we pose the following three research questions (RQs) and answer them through experiments:  
* RQ1: How does the performance of GMN+ compare to baseline methods?
* RQ2: What contributions do different modules of GMN+ make to its performance?
* RQ3: How does GMN+ perform in real-world vulnerability detection tasks?
# Telepresence Social Robotics towards Co-Presence: A Review
## 2 Co-Presence Taxonomy
### Immersive Qualities
#### 2.1.7 Video and Display  
The sense of being telepresent is also determined by the fidelity and capability of the medium to present the remote environment, including the visualization of persons (face expressions, gestures, postural behaviors, etc.). To this end, there are mediation technology requirements that include visual display parameters (e.g., latency, frame rate, field of view (FOV), point of view (egocentric vs exocentric), image resolution, color quality, and image clarity) and environment presentation consistency across displays [80]. Display type comparisons reveal a positive effect on co-presence using immersive 3D displays in nonverbal interactions [81]. For example, the Willow Garage Texai robot rely on the principle \"reciprocity of vision (if I see you, you must see me)\", while Excite robot designers defend that \"The visitor's [user's] environment should be immersive so that the user would have a first-person experience of the destination [remote environment] including full sensory stimulation focusing on immersive vision, audio, and haptics\" [3].
## 4 Conclusions  
This research analyzes the critical shift from traditional steel reinforcement to the use of fiber-reinforced polymer (FRP) materials, specifically, glass fiber-reinforced polymer (GFRP) and basalt fiber-reinforced polymer (BFRP), in small concrete beams. Based on the experimental study, the following conclusions were drawn:  
Figure 7: Crack development in tested concrete beams: (**a**) ABST-1; (**b**) ABST-2; (**c**) ABGF-1; (**d**) ABGF-2; (**e**) ABBF-1; (**f**) ABBF-2.  
* A comprehensive investigation into the mechanical characteristics of GFRP- and BFRP-reinforced concrete beams in comparison to concrete beams that are reinforced with traditional steel bars was carried out.
* GFRP-reinforced concrete beams demonstrated an ultimate load-bearing capacity of 36.9 kN, outperforming BFRP-reinforced concrete beams and steel-reinforced concrete beams, which exhibited average ultimate load-bearing capacities of 28.4 kN and 20.9 kN, respectively.
* GFRP-reinforced concrete beams demonstrated notable strength and resilience, leading to later failure stages compared to their steel-reinforced counterparts.
* The deflection analysis highlighted the remarkable performance of GFRP-reinforced concrete beams, showcasing their superior strength and deformation properties in comparison to BFRP-reinforced concrete beams. However, both displayed higher deflections compared to concrete beams with steel reinforcement. On average, BFRP-reinforced concrete beams experienced a 122.85% increase in the maximum deflection, while GFRP-reinforced concrete beams exhibited a 61.21% increase when compared with steel-reinforced concrete beams.
* The examination of failure modes demonstrated that both GFRP- and BFRP-reinforced concrete beams exhibited a bending property before failure, while those that were reinforced with steel broke easily without bending much. This provides valuable insights into their distinct failure mechanisms.
* This study is limited to the examination of small concrete beams, which requires further studies regarding the applicability of the findings to full-sized beams. Additionally, further research and development of design models are recommended to address deflection issues associated with concrete beams reinforced by non-metallic reinforcements.  
Conceptualization: A.A.B., J.K. and M.K.-K.; Methodology and experiment: A.A.B., J.K. and M.K.-K.; Formal analysis and investigation: A.A.B.; Resources: A.A.B.; Writing--original draft preparation: A.A.B.; Writing--review and editing: J.K. and M.K.-K.; Supervision: J.K. and M.K.-K. All authors have read and agreed to the published version of the manuscript.  
The research is funded from Bialystok University of Technology; Project number WI/WB-III/9/2023. This research work was financially supported by the National Centre for Research and Development, Poland; project number LIDER XIV Nr LIDER14/0206/2023.  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare no conflicts of interest.
## 4 Results and Discussion  
### Prototype  
Two experiments were conducted to verify the analysis results. The first one was a magnetic flux leakage measurement using a Kanetec Gauss meter (TM-701); the experimental set-up is shown in Figure 3.  
The second experiment involved the displacement and impedance of the linear vibration motor measured using Klippel equipment, a laser-based system that enables highly precise measurement. It included the power amplifier (PLX 1802), the distortion analyzer 2 (H1-DA2), the Klippel motor control, the computer, and the laser scanner. After applying the voltage to the linear vibration motor, the displacement could be detected by a laser, which depended on the frequency. In addition, according to the current sensor, the impedance was calculated by dividing the measurement current by the applied voltage. The set-up of the Klippel equipment is shown in Figure 4.  
Figure 3: Set-up of Kanetec Gauss meter.  
Based on the analysis methods, the analysis results of the prototype showed that the magnetic flux leakage at the measurement point was 643.7 G, which was only 1.05% different from the experimental result (637.0 G), as shown in Figure 5. The displacement and impedance obtained from the analysis results matched well with those obtained via the experimental results, as shown in Figure 6. The experiment results satisfied the motor performance requirements except for the magnetic flux leakage requirement. Thus, the analysis methods could be used to design a new linear vibration motor.  
By using the same analysis methods, three new designs were analyzed by comparing the force factor and the magnetic flux leakage. In a linear mechanical system, there is a linear relationship between the exciting force and displacement. The force factor can be used to represent the excitation force. The total coil length of the prototype was 4.97 m. The target value of the magnetic flux leakage was less than 50 G, maintaining the same performance as the prototype.  
Figure 4: Set-up of Klippel equipment.  
Figure 5: Magnetic flux leakage of the prototype: (**a**) analysis result; (**b**) experiment results.
# Design and Implementation of Industrial Accident Detection Model Based on YOLOv4
## 5 Conclusions  
In this study, three manufacturing industries were selected, common risk scenarios were extracted, and an industrial accident prevention model was implemented using an object detection model. Among the common risk scenarios, collisions between workers and moving objects and workers failing to wear safety equipment were identified. The model was evaluated in terms of time and accuracy for application in actual environments at industrial sites. The inference time was approximately 18 ms and the precision of the risk judgment was 97.06%.  
This study used data preprocessing to detect objects and identify hazardous situations. Direct object labeling information, risk event information, and metadata of the corresponding video were combined into a single JSON format file. However, as the model was designed based on rules for risk detection and the algorithm was designed to meet these rules, it showed high accuracy. However, a limit exists insofar as its application to other industrial sites. In the evaluation results, the false negative rate slightly increased in the risk judgment, showing a drop in the recall rate. This is a situation that the model judged to be hazardous but was not hazardous. This situation can eventually cause inconveniences to workers or employers working in actual industrial sites; corresponding studies are left for future research.  
In addition, it is believed that the deviations depending on the CCTV installation environment will vary greatly. Most CCTVs are installed at high angles, making it difficult to identify objects. In addition, they may be covered by lighting facilities installed in industrial sites, installed medium-large equipment, etc. Moreover, the data collection process may become biased when directly applied in the workplace. For example, data representing hazardous situations collected from the workplace may be excluded, i.e., administrators operating the CCTVs may delete these data to avoid institutional penalties. In such a case, the model will only train on safe situations, so it may fail to detect unsafe situations. Although this study did not solve all of these limitations, it showed that risk detection based on object detection is possible. Thus, this study can contribute to worker safety via industrial accident prevention solutions and safety manager environmental monitoring systems.  
Conceptualization, T.L.; methodology, T.L. and K.W.; software, T.L.; validation, T.L. and P.K.; formal analysis, T.L. and K.W.; writing--original draft preparation, T.L.; visualization, T.L.; supervision, H.J.; project administration, H.J. All authors have read and agreed to the published version of the manuscript.  
This research was supported by Regional Innovation Strategy (RIS) through the National Research Foundation Korea (NRF) funded by the Ministry of Education (MOE) (2021 RIS-004).
## 4 Results and Discussion
### Methodological Efficiency at Various Depths of Observation  
In order to assess the effectiveness of fluorescence imaging at different depths of penetration, we designed an experiment to view the same tissue slice at depths of 10 \(\upmu\)m, 40 \(\upmu\)m, 60 \(\upmu\)m, and 120 \(\upmu\)m preserving comparable spatial resolution (zoom level). This was done by adjusting a square window (blue borders) at the same horizontal and vertical coordinates in each image. The images presented in Figure 4 were examined by a medical expert to assess the similarity of regions and also assign distinct tumor regions of interest. Three areas of tumor concentration are depicted at depth 10 \(\upmu\)m, which are indicated by the colored arrows in Figure 4. The same regions are tracked over different depths allowing the evaluation of their growth/penetration patterns. The first area (blue arrow) shows significant penetration up to 40 \(\upmu\)m, whereas the second region (pink arrow) penetrates deeper up to 60 \(\upmu\)m. The third region (green arrow) appears to be the most aggressive tumor formation; it spreads to the right and penetrates all the way to 120 \(\upmu\)m. Based on the assessment of the clinician, the fluorescence imaging technique has a good capacity to encode the structure of the tumor and its borders at various depths of penetration. The subsequent enhancement by image processing approaches is expected to clearly reveal the topological characteristics of the tumor and enable quantitative measurements of its structure.  
Figure 3: Schematic representation of notations for performing qualitative and quantitative assessments on image segmentation performance.
# Genetic Algorithm as a Tool for the Determination of the Self-Stress States of Tensegrity Domes
## 2 Methods of Analysis
### Spectral Analysis of Compatibility Matrix  
The equilibrium equations of the tensegrity structure can be presented, e.g., in the form of symmetrized equilibrium equations:  
\[\mathbf{B}\mathbf{B}^{\mathbf{T}}\mathbf{S}=\mathbf{B}\mathbf{P} \tag{4}\]  
where \(\mathbf{P}\big{(}\in\mathbb{R}^{n\times 1}\big{)}\) is an external load vector, \(\mathbf{B}\mathbf{B}^{T}\)(\(\in\mathbb{R}^{n\times n}\)) is a compatibility matrix. The spectral analysis of the matrix \(\mathbf{B}\mathbf{B}^{\mathbf{T}}\), with non-negative eigenvalues, leads to the identification of the self-stress states [6; 7; 9; 10]:  
\[\Big{(}\mathbf{B}\mathbf{B}^{\mathbf{T}}-\mu\mathbf{I}\Big{)}\mathbf{y}=0 \tag{5}\]  
Figure 1: Global degrees of freedom of element \(e\).  
If all eigenvalues \(\mu\) are positive definite, there are no self-equivalent systems of longitudinal forces in the structure. The zero eigenvalues \((\mu_{i}=0)\) of the matrix (5) are related to the non-zero solution of the homogeneous equations ((4) for \(\mathbf{P}=\mathbf{0}\)) called the self-stress state, or more precisely to the self-balanced normal forces that satisfy the homogeneous equilibrium equations. The self-stress state can be considered as an eigenvector related to the zero eigenvalue \(\mathbf{S}=\mathbf{y}_{i}(\mu_{i}=0)\). The self-stress state \(\mathbf{S}\) is appropriate when the eigenvalues of the matrix (2) are positive definite and the forces correctly identify the type of elements.
# Use of Wearable Sensor Technology in Gait, Balance, and Range of Motion Analysis
## 6 Discussion
### Limitations  
Some of the studies included in this review had similar limitations: small sample size, lack of description of inclusion/exclusion criteria, and data loss was not reported. Additionally, there were studies that did not provide sufficient information about the protocols followed to perform assessments, making it difficult to make comparisons among studies. A limitation of the studies is that the results presented mostly represent the use of wearable sensors in controlled environments or laboratory settings. Furthermore, most of the studies did not include a long-term follow-up assessment. Research in work and home environments as well as long-term follow-up studies are needed in order to consider the use of wearable sensor technologies to assess gait, balance, and RoM in daily life. By monitoring activities of daily living, early detection of walking deviations and assessments of the ability of an individual to live independently in their community will be more complete, reliable, and correlated to individual's usual behavior. Another limitation is that optimum sensor locations to extract gait, balance, and RoM parameters are still inconclusive due to the variety of locations used in the literature. This affected the level of obtrusiveness in some studies since they used multiple devices attempting to get as much reliable data as possible. Knowledge of the most optimal sensor locations will help future research to reduce processing power and energy consumption needed to extract gait, balance, and RoM parameters. Furthermore, this will also decrease the level of obtrusiveness. If obtrusiveness is minimized, it may not interfere with trial results as much since the subjects may feel more comfortable participating in the trial.