esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Results and Discussion
### Microscopic of Sands and Bonding Sections
#### 3.5.2 Matrix Transition Zone and Hydration Product Analysis
The NSPE\(-\)ECC matrix's C\(-\)S\(-\)H gel developed more quickly during the hydration process because the actual development form of C\(-\)S\(-\)H gel was from flocculent to block\(-\)like polymer. Figure 10 shows that the strengths of the DSPE\(-\)ECC's matrix C\(-\)S\(-\)H gel at 3 and 28 days were lower than those of the NSPE\(-\)ECC's matrix C\(-\)S\(-\)H gel. This finding indicates that the bonding strength of NSPE\(-\)ECC is stronger than that of DSPE\(-\)ECC, but the strength gap between the two C\(-\)S\(-\)H gel strengths is considerably reduced at 28 days. This outcome was because the desert sand's strength increased with curing ages, and the influence of water absorption saturation on cement hydration decreased, resulting in the same bonding properties for DSPE\(-\)ECC and NSPE\(-\)ECC. Figure 11: Matrix C\(-\)S\(-\)H gel history diagram: **(a)** 3 d, **(b)** 28 d of NSPE\(-\)ECC, **(c)** 3 d, **(d)** 28 d of DSPE\(-\)ECC. Figure 12 shows that more C\({}_{2}\)S and C\({}_{3}\)S undergo hydration reactions in the absence of desert sand in the NSPE\(-\)ECC matrix to generate large and irregular flat or fiber\(-\)reticulated C\(-\)S\(-\)H gel. Moreover, the uneven appearance of the natural sand surface created a larger reaction gap for the cement, causing the generated C\(-\)S\(-\)H gel to adhere to the gap, thereby increasing the bonding area and enhancing the bonding properties of NSPE\(-\)ECC. The DSPE\(-\)ECC desert sand had a low water content and a high water absorption rate. It absorbed free water that should be involved in cement hydration, which affected the cement hydration reaction, reduced the generation of C\(-\)S\(-\)H gel in DSPE\(-\)ECC, and caused the bonding properties of DSPE\(-\)ECC to be inferior to that of NSPE\(-\)ECC. Therefore, as DSPE\(-\)ECC aged, its performance became increasingly more stable, and its ultimate tensile load was only marginally lower than that of NSPE\(-\)ECC at 28 days. The addition of desert sand also improved the fiber/matrix interface, resulting in a matrix cracking load greater than that of NSPE\(-\)ECC and the formation of ductility and multi\(-\)crack steady\(-\)state cracking. However, the high water absorption of desert sand slowed down the cement hydration process, which resulted in a distinction between the interfacial bonding properties of NSPE\(-\)ECC and DSPE\(-\)ECC at 3 and 28 days. If DSPE\(-\)ECC was cured for a longer period, its bonding properties would tend to be more stable, which has many practical applications.
# Ultra-Wideband Analog Radio-over-Fiber Communication System Employing Pulse-Position Modulation
###### Abstract  
This research presents a novel approach to 28 GHz impulse radio ultra-wideband (IR-UWB) transmission using pulse position modulation (PPM) over an analog radio-over-fiber (ARoF) link, investigating the impact of fiber-based fronthaul on the overall performance of the communication system. In this setup, an arbitrary waveform generator (AWG) is employed for PPM signal generation, while demodulation is performed with a commercial time-to-digital converter (TDC) based on an event timer. To enhance the reliability of transmitted reference PPM (TR-PPM) signals, the transmission system integrates Gray coding and Consultative Committee for Space Data Systems (CCSDS)-standard-compliant Reed-Solomon (RS) error correcting code (ECC). System performance was evaluated by transmitting pseudorandom binary sequences (PRBSs) and measuring the bit error ratio (BER) across a 5-m wireless link between two 20 dBi gain horn (Ka-band) antennas, with and without a 20 km single-mode optical fiber (SMF) link in transmitter side and ECC at the receiver side. The system achieved a BER of less than \(8.17\times 10^{-7}\), using a time bin duration of 200 ps and a pulse duration of 100 ps, demonstrating robust performance and significant potential for space-to-ground telecommunication applications.  
microwave communication; optical fiber communication; space communications; microwave photonics; energy efficiency; ultra wideband technology +
Footnote †: journal: Applied Sciences  
Article
## 5 Case Study
### Performance Analysis
#### 5.2.3 Analysis of Stop Indexes  
A stop plan is a spatial-temporal 0-1 matrix, so the stop indexes include the indexes of temporal stop distribution (stops at stations) and spatial stop distribution (train stops) to represent the service level and stop distribution balance.  
Table 6 shows the station stop indexes of the three stop plans. The stop ratio of a station is the ratio of the stop number to the passing train number at the station. Overall, the changes are slight. In the three stop plans, almost all trains stop at provincial stations because provincial stations have huge volume of passenger demand due to their attraction effects [49] and it is needed to provide sufficient services to satisfy the travel desires. The proposed approach slightly reduces the stops at district stations while adding those at county stations to rebalance the stop distribution according to the optimization orientation. This also indicates that the stop ratios would decrease with the decrease in station importance.  
Figure 8 illustrates the distributions of train stop ratios on each segment. The train stop ratio is the ratio of the stop number to the passing station number of the train segment. Figure 8 shows approximate trends to Figure 7. As for a specific segment, the numbers of trains with different stop ratio ranges in the OSP present more uniformly than those in the other two stop plans, especially compared to the PSP. This means that train stop ratios would also become more balanced with the mitigating of stop distribution imbalance. The two indexes would be simultaneously improved.
# Smart Healthcare Applications over 5G Networks: A Systematic Review
## 3 Results and Discussion
### RQ3: What Are the Security Mechanisms or Protocols Required by Smart Health Systems Based on 5G?  
By using IoMT devices in smart healthcare, patient information and medical systems are at risk of cyber attacks. Through them, patient privacy is compromised, and hackers can make use of user data, violating the confidentiality of the information with perverse intentions.  
The security and privacy of the information contained in the systems are paramount and must be safeguarded. However, the results obtained in Figure 13 show that 47.73% (\(n=21\)) of the studies do not mention or consider as a priority the implementation of security methods or protocols in their work.  
Based on the analysis of the works, three systems related to the security of information management, both in transmission and in storage and access, were identified. These systems are authentication, encryption, and coding, which are detailed below.
# A Low Complexity Reactive Tabu Search Based Constellation Constraints in Signal Detection
## 5 Conclusions  
In this work, we propose an improved RTS algorithm based on constellation generated candidates for massive MIMO systems. By using the Euclidean distance metric, the proposed algorithm separates the unreliable estimates from the reliable ones and generate new tabu search lists. With this algorithm, a significant number of candidates can be reduced and the detection complexity is further reduced. The simulation results indicate that the proposed scheme has helped to achieve significant reduction in detection complexity of traditional RTS algorithm.  
**Author Contributions:** [PERSON] designed the signal model and edited the paper; [PERSON] was responsible for designing and simulating the signal detection algorithm and writing the paper; [PERSON] supervised the paperwork and comments; [PERSON] provided writing advice.  
**Funding:** This work has been supported by National Natural Science Foundation of China (grant number 61501244), (grant number 61501245); Natural Science Foundation of Jiangsu Province (grant number BK20150932). Priority Academic Program Development of Jiangsu Higher Education Institutions, Innovation and Entrepreneurship Doctoral Program of Jiangsu, Startup Foundation for Introducing Talent of Nanjing University of Information Science & Technology.  
**Conflicts of Interest:** The authors declare no conflict of interest.
## 8 Reduced-Order Vibroacoustic Computational Model
### Computation of the Projection Basis for the Internal Acoustic Fluid  
#### 8.2.1 Case of a Gas or a Liquid without Free Surface  
The undamped acoustic modes of a closed (sealed wall) or an almost closed (non-sealed wall) acoustic cavity \(\Omega\) are computed. Setting \(\lambda=\omega^{2}\), we have the \((n\times n)\) generalized symmetric real eigenvalue problem  
\[\left[\mathbb{K}\right]\mathbb{P}=\lambda\left[\mathbb{M}\right]\mathbb{P}\,. \tag{44}\]  
This generalized eigenvalue problem admits a zero eigenvalue with multiplicity \(1\), denoted as \(\lambda_{0}\) (corresponding to constant eigenvector denoted as \(\mathbb{P}_{0}\)) and admits an increasing sequence of \((n-1)\) strictly positive eigenvalues (corresponding to the acoustic modes),  
\[0<\lambda_{1}\leq\ldots\leq\lambda_{n-1}\,. \tag{45}\]  
Let \(\mathbb{P}_{1},\ldots,\mathbb{P}_{n-1}\) be the eigenvectors (the acoustic modes) associated with \(\lambda_{1},\ldots,\lambda_{n-1}\).  
* _Closed (sealed wall) acoustic cavity_. Let be \(0<N\leq n\). We introduce the \((n\times N)\) real matrix of the constant eigenvector \(\mathbb{P}_{0}\) and of the \((N-1)\) acoustic modes associated with the first \((N-1)\) strictly positive eigenvalues, \[\left[\,\mathcal{P}\,\right]=\left[\,\mathbb{P}_{0}\,\mathbb{P}_{1}\,\ldots \,\mathbb{P}_{N-1}\,\right].\] (46)
* _Almost-closed (non-sealed wall) acoustic cavity_. Let be \(0<N\leq n-1\). We introduce the \((n\times N)\) real matrix of the \(N\) acoustic modes associated with the first \(N\) strictly positive eigenvalues, \[\left[\,\mathcal{P}\,\right]=\left[\,\mathbb{P}_{1}\,\ldots\,\mathbb{P}_{N}\, \right].\] (47) We have the orthogonality properties, \[\left[\,\mathcal{P}\,\right]^{T}\left[\mathbb{M}\right]\left[\,\mathcal{P}\, \right]=\left[M\right],\] (48) \[\left[\,\mathcal{P}\,\right]^{T}\left[\mathbb{K}\right]\left[\, \mathcal{P}\,\right]=\left[K\right],\] (49) in which \(\left[M\right]\) is a diagonal matrix of positive real numbers and where \(\left[K\right]\) is the diagonal matrix of the eigenvalues such that \(\left[K\right]_{\alpha\beta}=\lambda_{\alpha}\,\delta_{\alpha\beta}\) (for non-zero eigenvalue, the eigenfrequencies are \(\omega_{\alpha}=\sqrt{\lambda_{\alpha}}\)).
# Slope Failure of Noncohesive Media Modelled with the Combined Finite-Discrete Element Method
## 2 Method and Modelling  
In this section, the combined FDEM is briefly introduced. Some basics of the FDEM are addressed, and further details can be referred to [15]. In the FDEM, motions of elements are determined by traditional DEM equations. Translational and rotational motions of a single discrete element \(i\) is predicted from [PERSON]'s second law:  
\[m_{i}\frac{d^{2}}{dt^{2}}r_{i}=F_{i} \tag{1}\]  
\[l_{i}\frac{d}{dt}\omega_{i}=T_{i} \tag{2}\]  
where \(m_{i}\) is the mass of element \(i\); \(r_{i}\) is the position; \(l_{i}\) is the moment of inertia; \(\omega_{i}\) is the angular velocity; \(F_{i}\) and \(T_{i}\) are net external force and torque, respectively. Consequently, velocity and position of an arbitrary element can be obtained from Equations (1) and (2).  
Contact forces in the FDEM are computed from the overlapping area \(S\). Figure 1 shows two entities in contact. Infinitesimal contact force \(d\mathbf{f}\) exists in elemental penetration area \(dA\), as:  
\[d\mathbf{f}=-d\mathbf{f_{t}}+d\mathbf{f_{c}} \tag{3}\]  
where subscripts 't' and 'c' correspond to the target and contact, respectively. \(d\mathbf{f_{t}}\) and \(d\mathbf{f_{c}}\) are defined as follows.  
\[d\mathbf{f_{t}}=-E_{p}grad\ \varphi_{c}(\mathrm{P_{c}})dA \tag{4}\]  
\[d\mathbf{f_{c}}=-E_{p}grad\ \varphi_{t}(\mathrm{P_{t}})dA \tag{5}\]  
In Equations (4) and (5), \(\mathrm{P_{c}}\) and \(\mathrm{P_{t}}\) are points on contactor and target which share the same coordinate on \(S\); \(\varphi_{c}\) and \(\varphi_{t}\) are predefined potentials; \(grad\) is the gradient and \(E_{p}\) is the contact penalty. Integrating \(dA\) over \(S\), contact force \(\mathbf{f}\) is obtained as:  
\[\mathbf{f}=E_{p}\int_{S}[grad\ \varphi_{c}(\mathrm{P_{c}})-grad\ \varphi_{t}( \mathrm{P_{t}})]dA \tag{6}\]  
Friction angle plays a role in the relationship between the shear strength and normal stress, as:  
\[\tau=\sigma\ \mathrm{tan}(\Phi)+c \tag{7}\]  
where \(\tau\) is the shear strength, \(\sigma\) is the normal stress, \(c\) is the cohesion and \(\Phi\) is the angle of internal friction. In compression, \(\sigma\) should be replaced with \(-\sigma\) in Equation (7).  
When modelling noncohesive media, no dummy joint elements are necessary to be accommodated between adjacent element pairs whose elements are initially in close contact. This suggests that the two elements are completely free and can naturally separate (see Figure 2). Only friction exists between their contact surfaces. It is worth mentioning that when modelling continua entities where fracture is not considered (e.g., steel frames or nonfailed mountain in following examples), any adjacent elements cannot separate.  
Figure 1: Contact force in the FDEM.
## 2 Basic Theory and Calculation Method  
### Disturbance Factors  
Usually, there are three factors that cause disturbance of surrounding soil by shield tunneling technology: First, the gap between segment lining and stratum due to the reasons of assembling segment lining, shield overcutting, shield snake-shaped, and shield body adjustment; although synchronous grouting is adopted, the grouting cannot completely eliminate the gap at present [66]; the second is the elastic-plastic deformation of the soil at the shield heading face, which is closely related to the soil characteristics and the additional force on the shield working face. Thirdly is the horizontal friction between the outer surface of the shield and the surrounding soil. Compared with the effect of the gap, the stratum movements caused by the additional force on the shield working face and the frictional force between the outer surface of the shield and the surrounding soil during tunnel construction is very small [67]. Therefore, this paper neglects the effects of the latter two factors when analyzing, and mainly studies the effects of the gap. Sources of stratum movements of shield tunnel are shown in Figure 1 and the coordinate system is set as shown in Figure 2[68].
Recent studies have suggested that the influence of different 3D-printers on the accuracy of the protocol is negligible [21; 22], whereas dimensional changes caused by prolonged storage have been reported [23]. Another critical aspect that might alter the accuracy of implant insertion and that has not gained much attention so far is the impact of steam autoclaving. The sterilization of the templates is fundamental, as they can come temporarily in contact with blood. According to international hygiene guidelines, including the Center for Disease Control and Prevention (CDC, USA) and the EU Regulations, they are critical medical devices and have to be sterilized before usage [6; 24]. Few recent studies could not find significant changes in template dimension after autoclaving [25; 26; 27], whereas the impact on biomechanical properties remains unclear. Alteration of the biomechanical properties, such as flexural properties and hardness of the template materials, might lead to inaccuracies in implant insertion. Thus, there is a quest for studies assessing the influence of steam autoclaving parameters, such as temperature, pressure, and duration of autoclaving. Furthermore, the effect of autoclaving on different resin-based materials manufactured with different printing methods, such as stereolithography (SLA), liquid crystal display stereolithography (LCD-SLA), and digital light processing (DLP), remains to be clarified. Therefore, the aim of this study was to evaluate the influence of steam autoclaving parameters on the Vickers hardness and flexural modulus of 3D-printed resin-based templates, manufactured using different resin materials and printing methods. The null hypotheses were that being subjected to autoclaving did not significantly change the specimen Vickers hardness HV 0.5 and the flexural modulus.
# A Traceable and Verifiable Tobacco Products Logistics System with GPS and RFID Technologies
## 5 Discussion
### Comparison  
We used the EU's final report [5] as the target of comparison, and Table 6 shows the comparison between our scheme and the EU's tobacco products logistics tracking system.  
The EU has proposed a scheme with a general database with the defined field. The flexibility of the general database is very low, because the predefined field is fixed in advance, and the query connection between multiple tables is hard to modify when the system needs to upgrade. Our scheme used a blockchain-based decentralized ledger, so the blockchain has the characteristics of high flexibility and data integrity. By the way, we used the signature mechanism to ensure the message non-repudiation issue.  
Additionally, both systems can trace the data record. However, our scheme provides verifiability between the records as the blockchain system has a strong connection between every record with blocks, and the newly added block contains the hash value of the previous block to ensure that the data are not easily tampered with.  
According to the EU's scheme, they need to set up the routing path before generating the tobacco ID. Compared to the EU scheme, our method can update the routing path dynamically via the logistics phase, where every record is appended to the chaincode's tobacco information. Therefore, the manufacturer, distributor, or retailer can transport the tobacco products more flexibly.  
To sum up, our blockchain-based method can improve the security and integrity of data and provide greater flexibility in updating logistics information.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **EU’s Scheme**[5] & **Our Scheme** \\ \hline
**Database** & General database &
\begin{tabular}{c} Blockchain-based \\ Decentralized ledger \\ \end{tabular} \\ \hline
**Flexibility** & Low & High \\ \hline
**Data integrity** & Low & High \\ \hline
**Message non-repudiation** & N/A & High \\ \hline
**Traceable record** & Yes & Yes \\ \hline
**Verifiable record** & No & Yes \\ \hline
**Tampering data** & Easy & Hard \\ \hline
**Tracking record** & Pre-set routing & Update routing dynamically \\
**establishment** & & \\ \hline
**Security analysis** & Yes & Yes \\ \hline \hline \end{tabular}
\end{table}
Table 6: Comparison of the tobacco products logistics system.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Message Length** & **4G (100 Mbps)** & **5G (20 Gbps)** \\ \hline
**Authentication Phase** & 3648 bits & 36 \(\upmu\)s & 0.18 \(\upmu\)s \\ \hline
**Issuing and Manufacture Phase** & 7296 bits & 71 \(\upmu\)s & 0.36 \(\upmu\)s \\ \hline
**Logistics Phase (Shipping)** & 3648 bits & 36 \(\upmu\)s & 0.18 \(\upmu\)s \\ \hline
**Logistics Phase (Receiving)** & 3648 bits & 36 \(\upmu\)s & 0.18 \(\upmu\)s \\ \hline
**Consumption Phase** & 3648 bits & 36 \(\upmu\)s & 0.18 \(\upmu\)s \\ \hline \end{tabular} Notes: \(L_{\text{ID}}\): an ID (144 bits): \(L_{\text{in}}\): a cipher message (512 bits); \(L_{\text{sig}}\): signature parameters (1024 bits).  
\end{table}
Table 5: Communication costs of the proposed scheme.
## 3 Background
### Heterogeneity in the Nodes of HPC Field  
Heterogeneity within the HPC field means that the field incorporates various computing infrastructures and architectures, making core configurations much more complex. However, this allows the end user to conveniently utilize diverse resources and enhance the overall computing power of the system. Heterogeneous architectures are significant to the scientific research community as they offer various computing resources that enhance the efficiency, scalability, and resilience of the system [30]. In addition, heterogeneous architectures comprise different kinds of computing nodes with various processor architectures. NUMA processors, such as Intel Xeon and AMD Opteron, can be observed widely used in HPC platforms [31]. These NUMA processors have dedicated local memory banks and local cores, allowing for significant performance improvements in applications like sequence alignment. The architectural features of NUMA processors, when employed in an HPC system, can lead to distinct performance advantages and various bottlenecks.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & & **GR = GTGTAC** & & \\ \hline
**SA Index** & **Rotations** & **Sorted-BWT** & **BWT** & **Sorted Index** \\ \hline
0 & \$GTGTAC & \$GTGTAC & C & 0 \\ \hline
1 & GTGTAC\$ & AC\$GTGT & T & 5 \\ \hline
2 & TGTAC\$G & \$CGTGTA & A & 6 \\ \hline
3 & GTAC\$GT & GTAC\$GT & T & 3 \\ \hline
4 & TAC\$GTG & GTGTAC\$ & \$ & 1 \\ \hline
5 & AC\$GTGT & TAC\$GTG & G & 4 \\ \hline
6 & CSGTGTA & TGTAC\$G & G & 2 \\ \hline \hline \end{tabular}
\end{table}
Table 1: An illustration of SA and BWT computations based on single GR sequence.  
The architecture of processors is illustrated in Figure 1, showcasing two commonly utilized NUMA nodes as examples: the Intel Xeon E5-4620 and the AMD Opteron-6376. These NUMA processors possess the capacity to accommodate up to four processors, totaling 32 cores, 64 threads, and a memory capacity of 128 GB. Although both NUMA processors have four NUMA nodes in their systems, they differ in terms of the interconnections between the processors. This is because, while the AMD Opteron is a network structure with complete linkages, the Intel Xeon uses a ring structure with a circular connection.  
Figure 2 demonstrates the critical principle of NUMA architecture: access to local memory is fast. If a processor requests memory that is not local, then ultimately, it is provided with access to the memory. However, latency is introduced compared to local memory. In NUMA architecture, local access generally refers to a processor accessing memory that is directly attached to that processor or is co-located in the same node. Remote access means that the cores on Processor 1 access memory, which is physically on another processor, Processor 2. In practice, this difference in memory access in NUMA architecture is essential for many research programs and hardware configuration optimizations in performance, but it is often ignored in HPC.