esa-sceva/satcom-chunk-collection huggingface dataset:
# Relative Positioning in Remote Areas Using a GNSS Dual Frequency Smartphone
###### Abstract  
The use of GPS positioning and navigation capabilities in mobile phones is present in our daily lives for more than a decade, but never with the centimeter level of precision that can actually be reached with several of the most recent smartphones. The introduction of the new GNSS systems (Global Navigation Satellite Systems), the European system Galileo, is opening new horizons in a wide range of areas that rely on precise georeferencing, namely the mass market smartphones apps. The constant growth of this market has brought new devices with innovative capabilities in hardware and software. The introduction of the Android 7 by Google, allowing access to the GNSS raw code and phase measurements, and the arrival of the new chip from Broadcom BCM47755 providing dual frequency in some smartphones came to revolutionize the positioning performance of these devices as never seen before. The Xiaomi Miss was the first smartphone to combine those features, and it is the device used in this work. It is well known that it is possible to obtain centimeter accuracy with this kind of device in relative static positioning mode with distances to a reference station up to a few tens of kilometers, which we also confirm in this paper. However, the main purpose of this work is to show that we can also get good positioning accuracy using long baselines. We used the ability of the Xiaomi Miss to get dual frequency code and phase raw measurements from the Galileo and GPS systems, to do relative static positioning in post-processing mode using wide baselines, of more than 100 km, to perform precise surveys. The results obtained were quite interesting with RMSE below 30 cm, showing that this type of smartphone can be easily used as a low-cost device, for georeferencing and mapping applications. This can be quite useful in remote areas where the CORS networks are not dense or even not available.  
smartphone; GNSS; Galileo; dual frequency; precise positioning; long baseline 2021218354. [[https://doi.org/10.3390/s21248354](https://doi.org/10.3390/s21248354)]([https://doi.org/10.3390/s21248354](https://doi.org/10.3390/s21248354))
## 3 Results and Discussion
### Compressive Strength and Initial Maximum Absorption  
Figure 6 shows the results of the compressive strength tests and the minimum acceptable limits, in both craft bricks (3.0 MPa) and extruded bricks (4.0 MPa) in accordance with NMX-C-036-ONNCCE-2013 [36] (in the particular case of the European Code, for clay bricks intended to be used in buildings in highly seismic zones, the minimum limit is raised to 5.0 N/mm\({}^{2}\)) [37]. The grey bars indicate the compressive strength resulting from the use of OC or Ai  
Figure 4: Weight loss caused by brick desiccation.  
Figure 5: Profiles and volumetric weights of the crushed samples.  
the mixture; while the blue bars refer to mixtures with OC or AiO but with the addition of M. Thus, globally, it is possible to determine the compressive strength of the studied variables as follows (all of them are greater than the minimum limits): compared to their respective reference samples, Variable of study-sand from Only Concrete-Mucilage (V-OC-M) led to a 9% compressive strength increase at 0.53 MPa, while Variable of study-sand from All in One-Mucilage (V-AiO-M) led to a 7% compressive strength increase at 0.65 MPa. These data evidence the favorable effect of the use of component M in the mixtures. Comparing both mixtures, V-AiO-M is 22% more resistant than V-OC-M, and thus the use of AiO as an OC replacement material can be considered--at least as far as resistance is concerned.  
The orange tilted lines show the absorption variation of the study samples deriving from the differentiating use of W or M: Compared to their corresponding references, the initial maximum water absorption value obtained with V-OC-M mixture is 15% lower, while it is 13% lower with V-AiO-M. Moreover, both samples also meet the maximum absorption requirements established in NMX-C-037-ONNCCE-2013 [38]. As regards initial maximum water absorption and compressive strength, the use of M generates identical deviations (2%), as compared to their corresponding references, enhancing coherence and solidity. OC shows a 52% lower absorption capacity than AiO and since the absorption of the components of a matrix is a parameter of interest (dosage, durability, etc.); this fact will have to be taken into account in deciding whether a sustainable brick is appropriate for a given application. Finally, the existence of other mechanical parameters (freezing-thawing, fire), physical parameters (density, water steam permeability, efflorescence, thermal conductivity, water movement, salt contents) or geometrical parameters (aspects, cracks, lumps, flaking, etc.) that may also have to be complied with in other countries [37], must be mentioned.
## 3 Experiment
### Data Analysis  
In order to avoid affecting the accuracy of the experimental data, the sampling frequency of the experimental instruments and equipment was set to 2 Hz. Based on the experimental information recorded by the recorder, a total of 616,841 HRV and 603,343 GPS data points were obtained from 8 areas (S, A, B\({}_{80}\), B\({}_{120}\), B\({}_{160}\), B\({}_{200}\), C, and D) on 3 experimental roads after eliminating abnormal data.
# Emerging Industrial Internet of Things Open-Source Platforms and Applications in Diverse Sectors
## 6 Example IIoT Use Cases
### Agriculture  
Many agricultural businesses provide solutions for tracking the health of crops and their environmental effects. Milesight, for instance, implemented a project to provide a wireless solution to meet the needs of customers in Austria [78]. This project was centered on collecting, interpreting, and displaying data from multiple LoRaWAN sensors incorporated into a crop health management system. This is essential to safeguard plants from extreme weather conditions when they are particularly susceptible to diseases.  
This project was a challenge due to various metrics, such as temperature, humidity, and sunlight, that are hard to collect data on and process manually. As weather conditions can be unpredictable, manual data collection can be difficult or even impossible [78]. The project was successful in reducing costs by decreasing the number of people needed to monitor crops. Furthermore, farmers were able to adjust soil- and crop-specific fertilization and plant nutrition based on visualized data, resulting in an increase in productivity [78]. In conclusion, the project was a success that enabled farmers to increase efficiency and productivity in their plots.
# REISCH: Incorporating Lightweight and Reliable Algorithms into Healthcare Applications of WSNs
## 4 The Proposed Data Collection Scheme
### _CS_ Side  
* In sending case to \(LS\), \(CS\) generates \(CS_{TS_{1}}\), \(CS_{Pseuda}\), \(CS_{OTP}\), and \(CS_{RN}\). \(CS\) uses \(CS_{TS_{1}}\) to test the message arrival time of the \(LS\). Depending on generated secret parameters, such as \(CS_{OTP}\), \(CS\) computes \(CsT_{1}\) and \(CsT_{2}\) temporarily.
* In addition, the \(CS\) generates a \(SigCS\) signature that includes the temporary value (\(CsT_{2}\)).
* At this point, the \(CS\) computes and sends \(CS_{m}\) to \(LS\) containing the sequence of parameters such as \(SigCS\), \(CsT_{1}\), \(CsT_{2}\), \(SS\) and \(CS_{RN}\).
* In receiving case from \(LS\), \(CS\) receives \(LS_{m}\) of \(LS\). The \(CS\) generates \(CS_{TS_{2}}\) new to test access time \(LS_{m}\). The \(CS\) calculates \(SigCS_{1}\) and \(SigCS_{2}\) similarly to \(SigLS_{4}\) and \(SigLS_{5}\) respectively.
* At this point, the \(CS\) checks matching \(SigCS_{2}\) and \(SigLS_{5}\), and, if the result is identical, it means that \(CS\) received patients' data from the \(LS\) correctly and integrated without any changes by malicious attacks.
# DAB Signal Preprocessing for Passive Coherent Location
## 2 Materials and Methods
### DAB Signal Preprocessing
#### 2.4.1 Clearing of PR and FIC Symbols  
After detecting the PR, the part of the baseband signal containing the four initial symbols of the frame (PR, 3 \(\times\) FIC) is cleared by changing the relevant samples to zero  
\[\begin{split} x(n)0,\\ n=n_{0}-N_{\rm margin},\ldots,n_{0}+4\times N_{\rm symb}\end{split} \tag{4}\]  
where \(N_{\rm margin}=128\) is applied to compensate the envelope detector's latency, and \(N_{\rm symb}=2492\) is the OFDM symbol duration expressed in samples. The frame structure after this modification is shown in Figure 6. The deterministic components (PR and FIC symbols) that repeat from frame to frame have been removed, and only a random part (i.e., MSC symbols) has been left.  
It has been shown [31] that after the PR and three FIC have been deleted from the received DAB frames, the periodical ambiguous peaks are no longer visible in the signal's autocorrelation function, as depicted in Figure 7.  
Figure 6: DAB frame with cleared PR and FIC symbols.  
The side peaks at \(\pm 1\) ms visible in Figure 7b result from the guard interval (and cyclic prefix insertion) in the OFDM signal. Several methods of reducing these peaks have already been investigated [17; 25; 26].  
The same modification is performed synchronously (i.e., on the same sample indexes) on the signal \(x_{\mathrm{s}}(n)\) from the surveillance channel  
\[\begin{split} x_{\mathrm{s}}(n)0,\\ n=n_{0}-N_{\mathrm{margin}},\ldots,n_{0}+4\times N_{\mathrm{ symb}}\end{split} \tag{5}\]  
before feeding it to the input of the PCL detection algorithm. As a continuation of the work presented in [31], we investigate another three methods of DAB signal preprocessing for PCL applications, which are described further.
# Eigenstate Transition of Multi-Channel Time Series Data around Earthquakes
## 4 Discussion
For such a system, EWS methods based on a state space model, in which an observational model and physical model are treated, may be required. There are other studies that focus on the aspect that earthquakes are critical phenomena. For example, regarding earthquake occurrence as point process, small earthquakes before large earthquakes were analyzed by the means of multiresolution wavelet analysis and natural time analysis [22]. It is proposed that we could know whether the crustal state is at a critical stage of earthquake occurrence by extracting critical parameters. Although the timescales they are focusing on are different from us, there is a possibility that they can be discussed on the basis of a common root, such as a micro model of earthquake, in the future. Another study considered multiple strain gauges installed at distant locations, that is wide area information, as a network, and captured the topological changes in the network structure before an earthquake occurs [23]. Their study considered multiple strain gauges at different locations as multi-channel and uses multi-channel anomaly spectrum analysis. On the other hand, we tried to capture the precursors of earthquakes from local multi-physical quantity relationships. It would be useful for developing our study to capture seismic activity with wide area information. There is a possibility that it enables estimating more information such as the location and timing of earthquake occurrence. Then, in order to discuss the relationship between time series data at spatially distant locations, spatial data interpolation techniques [24] would be necessary.
## 5 Evaluation
### Structured Expert Questionnaire  
To ensure the comprehensive assessment of the proposed framework, this study adopts the Semiotic Quality Framework (SEQUAL). Originally developed to evaluate the quality of conceptual models, SEQUAL provides a structured set of dimensions for assessing how well a model or framework communicates its intended meaning to different stakeholders. It evaluates factors such as syntactic quality, semantic clarity, pragmatic usefulness, and other related dimensions, making it a suitable choice for assessing the clarity, applicability, and relevance of the proposed construction framework [74,75]. The expert evaluation is conducted through a structured questionnaire, focusing on assessing the framework based on predefined dimensions derived from the Semiotic Quality Framework (SEQUAL) used to assess the quality of the proposed framework; it provides a structured approach to evaluating the framework based on multiple quality dimensions [74,75]. The SEQUAL quality statements with seven dimensions outlined below is assessed, as presented in Table 8.  
The questionnaire consists of 21 evaluation statements categorized under the seven key dimensions, which are presented to experts in the form of closed-ended questions. To further enrich the framework, an open-ended question (Q22) is included at the end of the survey, inviting experts to share additional feedback, suggestions, or critiques that may not have been captured in the structured items. This qualitative input aims to enhance the robustness and applicability of the framework. The participant information needed before responding to the evaluation statements, experts are asked to provide the following background information:  
* Name (Optional). * Occupation. * Profession (Grade). * Field of Work. * Country of Residence. * Years of Experience. * Relevant Experience in Lean Construction, BIM, and Emerging Technologies. The evaluation statements are assessed using a Likert scale as follows: 1 = Strongly Disagree; 5 = Strongly Agree. Table 9 states the questions' statements. \begin{table}
\begin{tabular}{p{42.7 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**N\({}^{\circ}\)** & **Quality Dimension** & **Statement** \\ \hline
1 & Physical & The framework and its relevant components are systematically structured, visually representing the relationships between BIM Uses, Lean Tools, and Emerging Technologies, making them available for stakeholders’ interpretation. \\
2 & Empirical & The framework is based on valid and practical knowledge that makes it applicable to real-world construction projects. \\
3 & Syntactic & Follow a standardized methodology, ensuring a structured and systematic representation of processes. \\
4 & Semantic & The relevance and meaningful representation of the framework’s components in addressing construction challenges. \\
5 & Pragmatic & Usefulness and applicability. \\
6 & Social & Stakeholder agreement and collaboration. \\
7 & Deontic & The framework’s ability to meet industry regulations, promote sustainability, and support innovation. \\ \hline \hline \end{tabular}
\end{table} 
Table 8: SEQUAL quality statements.
The control is possible for a large shaking table's input motion (i.e., 1-D, 2-D, 3-D, and multiples axis), and precise data measurement is probable [5]. On the other hand, limitations of large-sized, shaking table models may include the associated high cost of procurement and maintenance of actuators as the number of required actuators and payload increases [6]. In addition, large-size models often need outsized space to fit (or accommodate) the test setup, especially in small-spaced laboratories; the unavoidable long durations, laborious, and fatiguing requirements for sample preparations are notable associated limitations. The scaling laws for the two-phase mechanics of soil-fluid physics are still not well-understood [7]. It is well-known, in principle, that the similitude laws in stress and strain cannot be satisfied in reduced-scale physical model ST experiments [6; 8; 9]. However, studies related to the evolution of excess porewater pressures (PWP) during earthquakes may conveniently be physically modeled with the advent of high-resolution transducers, coupled with a reduced-scale physical model setup. For instance, the above is helpful for studies that involve applications investigating earthquake-induced flow failures, landslides on slopes, possible liquefaction mitigation methods, retaining walls, pile-soil interactions, and seepage issues. Overall, modeling soil undrained behavior under shaking table conditions appears to be more realistic when compared with other laboratory testing methods, such as triaxial testing. This is because the stress conditions and measured deformations in soil samples tested under triaxial and other laboratory tests are greatly affected by boundary conditions. The applied loads do not mimic actual field situations, such as infinite lateral extents [10]. In the current study, a 600N rated capacity ST was designed and fabricated at the Auckland University of Technology (AUT) Geotechnical Laboratory to assess soil liquefaction-related mechanisms and the evolution of dynamic PWP, after considering the initially mentioned limitations of conventional large-scale shaking tables. The weights of all the prepared model soils were controlled with an electronic weighing scale to ensure that the model mass did not exceed the actuator's rated capacity (i.e., 600N). A parametric study was carried out to investigate the evolution of the dynamic excess PWP in east coast sand (ECS) and other artificially created clayey ECS by varying the kaolinite contents within the ECS fabrics with 5%, 10%, 15%, 20%, and 30% by weight kaolinite compositions. The idea herein is to implement a more economical methodology for initial assessment of geomaterials with more soil-water repellency properties, which may be applied in soil replacement schemes during earthquakes/engineered fill construction works.
## 4 Conclusions  
This study aimed to quantitatively present the disaster response seismic performance by comparing the energy dissipation capacity of concrete panels inserted with carbon fiber grids, and the conclusions are as follows:  
1. The flexural strength of concrete panels was 8.08 MPa with no layers, 8.65 MPa with one layer, and 9.27 MPa with two layers, and increased with the increasing number of carbon fiber grids. Flexural strength increased by 7% with one layer and 15% with two layers compared with no layer.
2. The energy dissipation capacity of concrete panels was 0.06 kN\(\cdot\)m with no layers, 1.89 kN\(\cdot\)m with one layer, and 3.52 kN\(\cdot\)m with two layers, and increased with the increasing number of carbon fiber grids. Energy dissipation capacity increased by 30 times with one layer and 56 times with two layers compared with no layer and showed improvement in terms of seismic performance.
3. Concrete panels with carbon fiber grids showed 7-15% higher flexural strength and 30-56 times higher energy dissipation capacity compared with no carbon fiber grid. Especially because of the large increase in the energy dissipation capacity, the carbon fiber grid reinforcement method can be considered an effective method for improving seismic performance.
4. This study compared the flexural strength characteristics of panels using carbon grids to those of unreinforced concrete, and a comparison with panels using existing reinforcing bars and meshes will be carried out in the future.  
Methodology, S.K.; formal analysis, S.H.; investigation, S.K.; resources, S.K; writing--original draft preparation, S.H.; writing--review and editing, S.H.; supervision, C.C.; project administration, C.C.; funding acquisition, C.C. All authors have read and agreed to the published version of the manuscript.  
This research was supported by a grant (10083576) from the Industrial Material Core Technology Research Program funded by the Ministry of Trade, Industry and Energy of the Korean government.  
Not applicable.  
This research was supported by a grant (10083576) from the Industrial Material Core Technology Research Program funded by the Ministry of Trade, Industry and Energy of the Korean government.  
The authors declare no conflict of interest.
## 5 Data Analysis and Main Findings
### Assessment of Model Fit and Measurement Model  
A CFA enhances the measurement of the acceptance or rejection of a form. As such, it confirms the validity of a theoretical framework and identifies indicators that are unsatisfactory or that require improvement (Table 4). A CFA also contains the validity and reliability of SEM and specific measurement criteria that were used to assess the factors of BYOD programmes. Therefore, SEM was used to test the validity of the theoretical framework by examining and evaluating linear correlations between the constructs, which, in turn, was reflected in the hypothesis testing. Furthermore, the method test of a CFA ensures that a theoretical framework can be reused by other similar studies in the future [65]. As seen in Table 4, the internal measurements were calculated accurately. Composite reliability (CR) and the average variance extracted (AVE) are the most accurate tests of reliability and variance between factors. They can also be used in complex constructs and address the reliability of relevant constructs [66]. According to [67], the AVE should be used to measure the validity of model discrimination. The constructs of this present study correlated closely and are shaded in Table 4. A standardised CR of more than 0.6 [68] and an AVE of more than 0.5 are considered satisfactory [59]. Table 3 presents the AVE of this present study.
## 1 Introduction
Numerous studies have explored integrating VLC with FSO, RF, and PLC, and THz with FSO/RF, globally and in Portugal. However, regarding THz-VLC integration, as per the authors' understanding, no studies have been conducted in Portugal, and only two have been published worldwide [18; 19]. These two studies focused on enhancing communication networks for VR, addressing challenges like minimizing transmission delay and maximizing successful transmission probability. They did not compare THz-VLC performance with other communication technologies or evaluate system performance in terms of BER or outage probability. This paper is structured to comprehensively address the proposed system. It starts with Section 1 outlining this study's significance and objectives. Section 2 highlights this research's driving factors and unique contributions. Section 3 discusses the collaborative benefits and obstacles of these systems. Practical applications are showcased in Section 4. Section 5 provides a detailed technical framework, followed by Section 6 evaluating system performance. Section 7 discuss the findings from the simulations. Section 8 proposes areas for further research. Finally, Section 9 summarizes our key findings.