esa-sceva/satcom-chunk-collection huggingface dataset:
## 6 Conclusions  
The migration from LMR systems to next-generation public safety networks represents a significant opportunity for public safety agencies to enhance office-bound applications and enable new mission-critical solutions. By adopting standardized communication technologies, public safety organizations can have access not only to a portfolio of cellular features and capabilities but also to continuous innovations and enhancements. To better understand the opportunities brought by 4G and 5G technologies for public safety operations, we provided a state-of-the-art overview of cellular solutions ratified by 3 GPP to enable the deployment of next-generation public safety networks. In addition to communication technologies, we addressed another key factor in public safety operations, which are devices and assistant systems used by first responders. Specifically, we focused on wearable devices as part of a cellular-enabled IoLST ecosystem. We provided examples of use cases that show how wearable technology can help in delivering improved safety and situational awareness for first responders.  
Figure 8: Impact of the resource selection methods in sidelink transmission mode-2 on latency and reliability performance in MCPTT private calls.  
Motivated by the potential role of watch-type wearables in future public safety operations, we evaluated latency and reliability performance in MCPTT applications using LTE Cat M2 smartwatches. More precisely, we examined access time and packet delivery ratio with different combinations of sidelink-related parameters in MCPTT private and group calls. The goal of this evaluation was to shed light on the need for latency and reliability trade-off mechanisms in mission-critical applications. Additionally, we discussed novel 3 GPP standardization efforts that can be explored in an extended version of the former performance evaluation. The identified future considerations can allow for a deeper understanding of the support of wearable-based, mission-critical application requirements over next-generation public safety networks.  
Conceptualization, S.S.; investigation, S.S.; writing--original draft preparation, S.S.; writing--review and editing, S.S., J.H., and A.K.; supervision, J.H. All authors have read and agreed to the published version of the manuscript.  
The authors gratefully acknowledge funding from European Union's Horizon 2020 Research and Innovation programme under the Marie Sklodowska Curie grant agreement No. 813278 (A-WEAR: A network for dynamic wearable applications with privacy constraints, [[http://www.a-wear.eu/](http://www.a-wear.eu/)]([http://www.a-wear.eu/](http://www.a-wear.eu/)) (accessed on 25 August 2021)).  
Not applicable.  
The authors declare no conflict of interest.
## 2 State of the Art
### Routing Protocols
#### 2.2.2 Position-Based Routing Protocols  
These routing protocols base their operation on the knowledge of the geographical position of the nodes. Therefore, they are the most suitable routing protocols for FANETs with high mobility. Protocols in this category can be divided into (i) reactive-based, (ii) greedy-based, and (iii) heterogeneous.  
These types of protocols are based on a reactive technique and use the position of the nodes to obtain higher performance. In this category, we highlight the Reactive-Greedy-Reactive (RGR) algorithm [43]. RGR is based on the reactive routing protocol AODV [33] for the on-demand route lookup process, and for message delivery, it is based on the Greedy Geographic Forwarding (GGF) protocol [44]. Other reactive-based protocols are Ad Hoc Routing Protocol for Aeronautical Mobile Ad Hoc Networks (ARPAM) [45] and Multipath Doppler Routing (MUDOR) [46].
## 3 System Design Configuration  
The system design architecture for each satellite in the ISL network is made using COTS components. The use of small standard satellites has been chosen for the satellite design because of their fast development time and low cost. The design configuration is divided into two parts, the satellite bus and the _TWVC_ mission portions, as illustrated in Figure 4 below.  
The satellite bus can be a generic one. The interface between the mission payload and the satellite bus is simply made of power lines (5 V and 3.3 V) and a digital data line universal asynchronous receiver/transmitter (UART). The satellite bus turns on the mission payload based on either the command uplink from the ground station or through reserved commands in the satellite's onboard computer. The mission data will be downlinked to the ground station though the satellite bus. The water vapor mission measurement board is composed of the universal software radio peripheral (USRP) SDR model B205 mini-i, the RPi 4 model B, the amplifier and RF switches board, a GPS module, and the antenna (Antenna 1). Antenna 1 serves as the primary channel of communications. This channel is only used to transmit (_Tx_) and receive (_Rx_) SS ranging signals. Meteorological dual frequency bands (\(f_{1}=400.15\) MHz and \(f_{2}=460.00\) MHz) with a frequency gap of 59.85 MHz are reconfigured and used for SS transmission and reception. The SDR transceiver is used to transmit and receive the SS signal. To realize mission success in orbit, especially when  
Figure 4: System design configuration block diagram.  
the distances between the satellites is large, an RF amplifier is required to amplify the transmitted signal. The RFi 4 conducts digital signal processing on the mission data and is used to control the SDR parameters using GNU Radio software (v3.8.2.0). A GPS module is mounted on each satellite and at the ground stations. The GPS module provides the location, time, a 10 MHz clock, and a one pulse per second (1 PPS) signal. The location and time data are carried along with the SS signals. The 10 MHz clock eliminates the SDR's clock and instrument errors at both the transmitting and receiving SDRs. The 1 PPS time reference markers are superimposed on to the incoming and outgoing signals through the RF switches. When the GPS modules at both the receiving and the transmitting ends are synchronized, signal propagation time delay in the ISL network can be derived based on the 1 PPS time markers. Finally, _TWVC_ mission data are deduced from the signal time delay. When the SDR is in reception and transmission modes, the power consumption for this mission subsystem is estimated as 2.81 W and 8.50 W, respectively. Having one SDR to perform both the _Rx_ and _Tx_ of SS signals at different frequencies, not only saves satellite power but also mass and volume occupied by the mission subsystem compared to systems with multiple radio devices performing the same function.
###### Abstract  
Vehicle-to-vehicle (V2V) communication networks are based on vehicles that wirelessly exchange data, traffic congestion, and safety warnings between them. The design of new V2V systems requires increasingly energetically and spectrally efficient systems. Conventional multiple-input-multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems have been used successfully for the last decade. However, MIMO-OFDM systems need to be improved to face future communication networks in high-mobility environments. This article proposes an efficient index modulation (IM)-based MIMO-OFDM system for V2V channels. The proposed transmission system is evaluated in high Doppler-spread channels. The results demonstrate that the proposed scheme reduces the required computational complexity in data detection and exhibits gains of up to 3 dB in bit error rate (BER) performance when compared to the conventional MIMO-OFDM system under the same conditions and parameters, along with achieving superior spectral efficiency. The results show the viability of implementing the proposed system in practical applications for high-transmission-rate V2V channels.  
V2V channels; MIMO-OFDM; efficient index modulation [table]capposition=top  
0  
[table]capposition=top  
**MSC:** 68M10; 68M12; 90B18; 94A05
## 3 Results
### NDM and FDM Based Laplacian Estimates for Real Life LIIRD TCRE  
Laplacian estimate coefficients are not unique for both NDM and FDM. For NDM they are determined as a null space vector of a truncation term coefficient matrix and therefore are not unique [22]. For FDM, as shown in Section 3.1 they are also a solution of a system of linear equations. Since in both cases Laplacian estimate coefficients are determined up to (multiplication by) a constant factor they were scaled both for the NDM and for the FDM to a unit value of the first coefficient to allow direct comparison.  
Since one of the main limitations of the NDM is the negligible widths of the concentric rings, the Laplacian estimate coefficients were calculated as null spaces of the respective truncation term coefficient matrices [24] for three scenarios: separately for inner and outer radii of the two rings and for radii corresponding to the center of each ring since if each ring had to be represented as a circle with negligible width then the natural point estimate would have been the average of ring's inner and outer radii. The average of the coefficients obtained for the three scenarios yielded coefficients (1, \(-0.0446417\)) for the LIIRD TCRE case equivalent to the following NDM based Laplacian estimate:  
\[\begin{array}{l}\Delta v_{0}^{NDM}\cong 1\cdot(v_{MR}-v_{CD})-0.0446417 \cdot(v_{OR}-v_{CD})\\ =(U_{2}-U_{1})-0.0446417\cdot(U_{4}-U_{1})\end{array} \tag{16}\]  
For the FDM Laplacian estimate, first, the outer radius of the outer ring (radius of the LIIRD TCRE) was set equal to a large arbitrary numeric constant (e.g., 50,000). Next, the radius of the central disc and inner and outer radii of both concentric rings were expressed as integer fractions of this constant based on their actual dimensions from Table 2. For example, the radius of the central disc was set equal to \(4.8\times 50\),000/22.8 \(\approx\) 10,526. Finally, potentials on all the recording surfaces were calculated as averages of potentials on all the concentric circles included in them. For example, the potential on the central disc was calculated as the arithmetic mean of 10,527 potentials including one at the center of the disc and potentials on concentric circles with radii up to 10,526. Potentials on the recording  
Figure 6: Ratios of truncation term coefficients for term orders 6 to 22 (CIRD TCRE over LIIRD TCRE) based on the scaled (by a factor of 2/3) NDM and the FDM respectively.  
surfaces were combined in the manner identical to the Equations (10)-(15) from Section 3.1 above to obtain coefficients (1, \(-0.0443895\)) for the LIIRD TCRE case equivalent to the following FDM based Laplacian estimate:  
\[\begin{array}{l}\Delta v_{0}^{FDM}\cong 1\cdot(v_{MR}-v_{CD})-0.0443895\cdot(v_{OR}-v _{CD})\\ =(U_{2}-U_{1})-0.0443895\cdot(U_{4}-U_{1})\end{array} \tag{17}\]  
It can be seen that the two resulting Laplacian estimates for the LIIRD TCRE based on the NDM and the FDM (Equations (16) and (17) respectively) are virtually identical with the coefficient at (\(U_{4}-U_{1}\)) differing by less than 0.6%.
## 3 Results and Discussion
### Characterization of AuNPs
#### 3.2.5 UV-Visible Spectroscopy  
The purple color intensity, which was considered the first indicator for green synthesis of AuNPs, was monitored by UV-Vis spectroscopy to detect the maximum SPR (surface plasmon resonance). As shown, a single absorption peak is observed at \(\lambda_{\rm max}\) = 530 nm (Figure 4A); this SPR peak is typical of AuNPs and can be assigned to the free electron's collective oscillation in the conduction band [53; 61]. [PERSON] et al. [54] also observed a single plasmon band at 522-523 nm. [PERSON] et al. [26] reported that the appearance of a single SPR peak at a \(\lambda_{\rm max}\) in the range of 520-540 nm indicates the formation of tiny, monodispersed, and spherical AuNPs, which is consistent with TEM analysis. UV-Vis analysis (not shown) of the \(Z\). _official_ rhizome extract did not show any peak in this wavelength range; the SPR is thus characteristic of AuNPs. It is noteworthy that chemically mediated AuNPs have similar SPR values [74], and the purification of AuNPs with careful washing allows for the removal of the UV contributions of the residual plant extract (at low wavelengths), whereas the SPR peak remains unchanged at 530 nm. It is also noticeable that the width of the band remains relatively large, meaning that some residues are still present or that particles may partially aggregate.
# Blockchain Applications in Education: A Systematic Literature Review
## 4 Discussion
### Research Question 2: What Are the Features of Blockchain That Could Benefit Education?
#### 4.2.7 Security Provision  
Blockchain, due to its design and technology, assures security characteristics as integrity, availability, authentication and nonrepudiation for the stored transactions. Nevertheless, in many scenarios, information must be available to all members to provide transparency and verifiability, so confidentiality and privacy cannot be provided. To solve this, some blockchains are specifically designed with mechanisms to provide these.  
The blockchain's peer-to-peer nature helps to reduce the security risks in education, since information (i.e., certificates, grades and competences discussed in Sections 4.1.1-4.1.4) is tamper-proof stored, authenticated and protected against repudiation because it is signed by the issuers, and it is highly available due to its peer-to-peer distribution, which supports the creation of trustful information even in unsecure environments.  
These blockchain characteristics are also used in combination with other technologies to authenticate and check the integrity of learning resources in MOOCs for teachers and learners [18], manage the access and use of multimedia resources [21] or exam questions [22].  
Privacy and confidentiality are features that are not easy to achieve in public blockchains, because all of the information is public and is needed to verify transactions. To solve this, hash codes of the information are stored in the blockchain instead of the actual content of the records, which are stored off-chain and encrypted. The system is controlled by smart contracts [19; 26].  
An alternate solution consists of a private or consortium-based blockchain platform to restrict access to academic data to authorized participants, to protect recipients' privacy and confidentiality [14; 25; 37]. [PERSON] et al. [34] develop their initiative over Quorum, which supports private transactions between network members.  
[PERSON] et al. [43] propose a model using Tangle, a distributed ledger that achieves a quantum resistant security, that adds promising features to secure academic information.  
Note that the accountability of blockchain is a key point to trustfully register token's transfers, as discussed in Sections 4.2.4, 4.2.6 and 4.2.9.
# Predicting Architectural Space Preferences Using EEG-Based Emotion Analysis: A CNN-LSTM Approach
## 3 Materials and Methods
### Experiment Design and Procedure
#### 3.3.4 Experimental Procedure  
Participants were seated in a noise-controlled environment. Prior to the experiment, participants were instructed to, as follows:  
* Avoid excessive movement to minimize EEG artifacts.
* Maintain a visual fixation on the screen during the stimulus presentation.
* Rate each image based on their intuitive emotional response.  
To establish baseline resting-state brain activity, participants first gazed at a black screen for 60 s while EEG signals were recorded. Subsequently, architectural images were presented sequentially, and EEG responses were continuously recorded. Each trial proceeded as follows (see Figure 6):  
1. Stimulus Presentation (\(t\) = 0): an architectural image was presented for 5 s.
2. Participants rated the image using a keyboard, selecting one of three options (1: like; 2: neutral; or 3: dislike).
3. An interval of 2 s was introduced between each stimulus to prevent neural carryover effects.
4. The trial sequence was repeated 100 times for a total duration of approximately 12 min.  
The EEG data were stored in multiple formats (easy,.edf,.nedf, and.info). Event files recorded the timestamp for image presentation, response inputs, and the preference code (i.e., 1: like, 2: neutral, and 3: dislike).  
Figure 5: The experiment space layout: (**A**) Standing Desk; (**B**) Keyboard; (**C**) Monitor.
# Extended SSH Model in Non-Hermitian Waveguides with Alternating Real and Imaginary Couplings
## 5 Conclusions  
In summary, we have investigated an extended SSH model in optical waveguides with real and imaginary couplings. Imaginary coupling is employed through adiabatic elimination and appropriately fixing the onsite gain and loss in different waveguides. The system supports two bands, and the topological invariant of the system remains quantized even though the system is non-Hermitian. The energy bands of the periodic system are generally complex but coalesce at the exceptional point, with the Bloch momentum zero value of \(\varphi=\pm\,\pi/2\). We show the topological phase transition also takes place at this point. Topological zero mode is supported at the edge of nontrivial structures when chiral symmetry is preserved. By adding onsite gain and loss to break chiral symmetry, the topological bound modes no longer remain at zero energy and dominate in all supermodes with the maximum absolute value of the imaginary part of propagation constants. This work enriches study of the SSH model and may find great applications in optical routers and switches.  
Conceptualization, S.K.; software, Z.F. and N.F.; formal analysis, Z.F., Z.W. and H.Z.; writing--original draft preparation, D.Z.; writing--review and editing, S.K. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Program for Distinguished Middle-aged and Young Innovative Research Team in Higher Education of Hubei, China, grant number T201806; the Natural Science Foundation of Hubei Province, grant number 2017 CFB150; and the 14 th President's Fund of Wuhan Institute of Technology.  
The authors declare no conflict of interest.
## 3 Results and Discussion
### Oxide Surface Characterization
#### 3.1.1 Oxide Crystallinity Analyses
While numerous studies have formed anodized hydroxyapatite coatings on titanium surfaces, only a few have reported the combination formation of hydroxyapatite, tricalcium phosphate, and calcium titanate, as observed in the present study [15]. A sol-gel coating study revealed that the formation of calcium titanate in an interlayer improved the adhesion strength between titanium alloy substrates and an outer hydroxyapatite layer [53]. Furthermore, evidence of calcium diphosphate formation was also found in the oxides formed on the TiMo \(\alpha+\beta\) and TAV duplex alloys in the present study.
# Performance Analysis of Dual-Hop DF Multi-Relay FSO System with Adaptive Modulation
## 1 Introduction
All hops are assumed to follow an \(\mathcal{F}\) turbulence channel with pointing errors. To enhance the performance of the considered system, AM and the RS techniques are presented. In addition to the ORS scheme, two sub-optimal schemes are proposed. In the first scheme, RS is based on the source-to-relay CSI, while in the second scheme, it relies on the relay-to-destination CSI. These sub-optimal schemes reduce complexity and power consumption compared to the optimal scheme. In order to analyze the system performance, expressions for the cumulative distribution functions (CDFs) of the received SNRs are derived for both optimal and sub-optimal schemes. Based on these derived CDF expressions, we present the performance analytical expressions in terms of OP, SE, and modulation level selection probability. The system's performance is analyzed under two scenarios: a balanced case where the distances between hops are equal, and an unbalanced case where the distances between hops are unequal. The correctness of the obtained expressions is confirmed using Monte Carlo (MC) simulations. The rest of this work is summarized as follows. Section 2 describes the system model. Section 3 presents the mechanism of AM. In Sections 4 and 5, we introduce the performance analysis of single- and multi-relay systems. Section 6 discusses the numerical results, where the performance metrics are presented and the findings are analyzed. Finally, in Section 7, we conclude the paper with a summary.
# Longitudinal Seismic Response of Continuously Welded Track on Railway Arch Bridges
## 3 Influence of Track Constraints on Arch Bridge Seismic Response
### Comparison of Rail Seismic Force  
The analysis focused on longitudinal seismic vibrations. According to existing research based on longitudinal track-bridge interactions, the force under seismic loading is several times larger than that due to temperature change [12; 15]. Therefore, the seismic effect on rail longitudinal forces should be considered when designing CWR on bridges in seismically active zones. Compared with vertical and transverse seismic vibrations, longitudinal seismic vibrations have the most direct and important effect on rail longitudinal force. The longitudinal force distribution of our track model is shown in Figure 5.  
Figure 4: Three seismic waves. (**a**) El-Centro wave; (**b**) San Fernando wave; (**c**) James RD wave.  
As seen in Figure 5, the peak rail seismic forces occur in the vicinity of the beam gap, which is similar to estimates of rail expansion force in regular calculations. The seismic force on the span of a simply supported beam at the arch center is the least, up to about 50 kN. This indicates that the track structure at the arch center is least prone to instability or damage when an earthquake occurs. When calculating the calculated rail expansion force, the'maximum rail seismic force' was taken to be the maximum absolute value of the tensile/compressive rail seismic force under unidirectional input of seismic waves. The peak rail seismic force (617.3 kN) is larger than the maximum expansion force (568.7 kN, see Figure 6); the latter was calculated according to existing codes for CWR tracks on bridges [17]. This reinforces the importance of a study of seismic impact on CWR track on bridges.
# SEA and GATOR 10 Years Later
## 8 GATOR in Human Diseases  
During the last decade it became increasingly evident that alternations in the expression of GATOR genes can cause various human diseases (Figure 6). Mutations of GATOR2 components can be found in various cancers according to The Cancer Genome Atlas (TCGA) and Cancer Cell Line Encyclopedia (CCLE), COSMIC and cBioPortal databases, although their recurrent mutation frequency is very low [173]. None of the GATOR2 mutations in these cancers were studied on the molecular level and currently there are no data about the involvement of GATOR2 components in other human pathologies [174]. One of the reasons of the low pathogenicity of GATOR2 mutations could be that they would cause an increased, but most probably not complete, suppression of the mTOR1 pathway, which can rather be associated with healthier conditions.  
In striking contrast to GATOR2, many pathological mutations in GATOR1 genes have been reported. These mutations are mainly related with two main types of human diseases--cancer and epilepsy. Although the alternations in sequence and gene expression associated with these pathologies have been reported for all three GATOR1 genes, there are striking differences that mark some kind of \"preferences\" of a gene for a pathology.  
Figure 6: Deregulation of GATOR1 components in different human diseases. Expression of GATOR1 components is downregulated in many cancers and GATOR1-related neurological disorders.  
Thus, DEPDC5 mutations are more frequent in epilepsies in comparison with mutations in other GATOR1 members. NPRL2 mutations can be found more often in different types of cancers and are associated with resistance to anticancer drugs cisplatin and doxorubicin. Even though NPRL3 is a paralogue of NPRL2, its alternations in cancer are less recurrent. Instead NPRL3 appeared to be required for the normal development of the cardiovascular system. Below we will describe alternations of GATOR1 expression in different diseases.