esa-sceva/satcom-chunk-collection huggingface dataset:
# Construction Management Risk System (CMRS) for Construction Management (CM) Firms
## 4 CRMS Development
### Contribution
#### 4.3.2 Advantages of CRMS in Comparison with Existing Risk Management Systems  
* Decreased work burden for field managers:  
Existing risk management systems lack standardized operating systems, which delays decision-making processes. Owing to this, it is difficult to apply early countermeasures to risk factors, which in turn causes an increase in the work load of managers and directors. However, CRMS allows work progress planning through early response processes, which allows work to progress effectively and minimizes additional task increments by reducing business confusion.  
* Decision-making support and results checking:  
Since existing risk management systems lack standardized operating systems, decision making processes are delayed and future business progress procedures regarding previously taken decisions cannot be confirmed. However, CRMS allows such information to be viewed at any time. Additionally, responsibilities and authorities can be granted to decision makers, easing risk response processes.  
* Records management:  
Existing risk management systems present disadvantages at managing data related to countermeasures taken against risks factors. Instead, the CRMS proposed herein stores data on risk response procedures. This data can be used in the future as preparation for lawsuits and legal disputes. Such information can also be used as knowledge management resources that may contribute to the company's technological improvement.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Existing Systems** & **FIRMS** & **RBES/RMP** & **TSRMP** & **CMRS** \\ \hline \multirow{2}{*}{Applicable system} & \multirow{2}{*}{\begin{tabular}{c} Overseas construction \\ corporation \\ \end{tabular} } & \multirow{2}{*}{Construction company} & Construction & Domestic CM \\  & & & company & company \\ \hline \multirow{2}{*}{\begin{tabular}{c} Degree of system \\ completeness \\ \end{tabular} } & \multirow{2}{*}{High} & \multirow{2}{*}{Moderate} & \multirow{2}{*}{Moderate} & \multirow{2}{*}{High} \\  & & & & \\ \hline System accessibility & High & High & Low & High \\ \hline \multirow{2}{*}{\begin{tabular}{c} System convenience \\ \end{tabular} } & \multirow{2}{*}{High} & Low & High & High \\ \hline \multirow{2}{*}{\begin{tabular}{c} Utilization of system \\ as an actual tool \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} Focused on the initial \\ stage of overseas \\ construction \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} Complex risk \\ management in \\ construction company \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} Only members \\ have access; weak \\ analysis function \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} Focused on the \\ field operation of \\ domestic CM firm \\ \end{tabular} } \\  & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: Comparison of CMRS to existing systems. RBES: risk-based estimate system; RMP: risk management plan; TSRMP: The Simple Risk Management Process.
## 3 Results
### Main Findings
#### 3.4.3 Effect of Inclinations on Spatiotemporal Parameters  
The lowest and most commonly used velocity in the analysis of spatiotemporal parameters was 2.8 m/s [31; 32; 33; 38]. Despite using different inclinations, three studies found no statistically significant differences for CT [31; 32; 33]. In the study of [PERSON] et al. [31], the difference between the extreme inclination was only 10 ms. In the study by [PERSON] et al. [32; 33], the CT decreased from 308 ms to 301 ms between \(-8\%\) and 8%. SF was analyzed by all four authors who used a velocity of 2.8 m/s [31; 32; 33; 38]. Three studies noted statistically significant changes in SF with increasing inclination (\(p<0.05\)). [PERSON] et al. [31] observed a clear difference only at an inclination of 17.6%, yielding an SF value of 2.81 Hz. [PERSON] et al. [32; 33] observed a steady increase in SF. In her study, she obtained a 0.12 Hz difference for a comparison of \(-8\%\) vs. 8%. Only [PERSON] et al. [38] did not observe significant changes in SF when changing the inclinations. Parameters such as AT, StL, and RStLwere investigated only by [PERSON] et al. [31]. Statistical analysis showed a statistically significant (\(p<0.05\)) decrease in AT and an increase in DF with each change in inclination. AT decreased by 0.2 s reaching a value of 0.7 s at an inclination of 17.6%. DF increased by 6.6% between extreme inclination values. StL and RStL decreased significantly only when the inclination increased from 0% to 17.6%. FT was investigated only by [PERSON] et al. [32; 33] who noted significant differences in this parameter with increasing inclination (\(p<0.05\)). A constant CT value of 71 ms was maintained for inclinations \(-8\%\) and \(-5\%\). Only at inclinations of \(-2\%\), 0%, and 2% was there a noticeable reduction in CT, reaching 63 ms for \(-2\%\) and 55 ms for inclinations of 0% and 2%. At inclinations of 5% and 8%, the execution time (FT) began to increase, reaching corresponding values of 56 ms and 59 ms.
## 4 Materials and Methods
### In Vitro Cell Viability Assessment  
The cytotoxicity of the blank and DFO-loaded NPs were evaluated by the conventional CCK-8 (Dojindo, Kumamoto, Japan) assay. Briefly, hBMSCs were seeded on 24-well plate (Corning, Inc., Corning, NY, USA) at a density of \(1\times 10^{4}\) cells/well, allowed to adhere overnight, and then solutions of blank NPs or DFO-loaded NPs were added. After incubating for 24, 48, and 72 h, the medium was removed and 100 \(\mu\)L of medium containing CCK-8 was added. Following incubation for another 2 h, the absorbance of the medium was measured using a spectrophotometer (Bio-Rad, Hercules, CA, USA) at 450 nm. The experiment was replicated for 3 times independently of each group.  
A Live/Dead cell staining (ScienCell, Carlsbad, CA, USA) assay was also performed to estimate the cell death ratio, which could serve as an indication of NPs or DFO toxicity. In brief, after 72 h of incubation, the Live/Dead cell staining solution was added to each well and incubated for a further 30 min, then images were captured from 6 randomly chosen fields of each sample using a fluorescence microscope and cell number was counted. Live cells were green with green-fluorescent calcein-AM and dead cells were stained red with red-fluorescent ethidium homodimer-1.
# Reduced Overhead Routing in Short-Range Low-Power and Lossy Wireless Networks +
## 4 Reduced Overhead Routing Protocol
### Point to Multi-Point Reduced Overhead Routing
#### 4.2.2 Data Packet Forwarding  
Whenever the root node has a data packet to transmit to another node in the network, it uses the network topology information to construct the source routing path to the destination node. For each node along the path to the destination node (excluding the source node), the root passes the node's address through the respective SAX hash function, and sets the resultant \(k\) bits in the bloom filter. Once the above process is complete for each node along the path to the destination node, the root inserts the resultant m-bit bloom filter array into the IP packet header, and forwards the packet to the next hop. When a node along the path to the destination receives the packet, it compares its address with the destination node's address present in the IP header. If both addresses match, the packet is forwarded to the transport layer. Otherwise, the node consults its neighbor table, and retrieves neighbor node addresses from it one after another. If a retrieved neighbor node address is of the node from whom the node received the packet, the neighbor is ignored. This check is essential otherwise routing loops can be easily created in the BF-based P2 MP routing. In IP data packet forwarding, a node does not have direct access to the forwarding node's IP address, however as the forwarding node is a neighbor of the node who received the packet, the node can obtain the forwarding node addresses from its neighbor table. Moreover, to successfully complete the above check, the MAC layer passes the forwarding node network layer address to the networking layer. For all other neighbor addresses, the node uses the same SAX hash function to obtain \(k\) bit positions. Afterwards, the node checks whether the values at the obtained \(k\) positions inside the m-bit array present in the packet header are set. If bits at those \(k\) positions are set, the node forwards the packet to the neighbor after decrementing the hop limit field in the protocol header. However, if any of the bits at those \(k\) locations is not set, the node extracts the next neighbor node address from its neighbor table, and repeats the  
Figure 5: Bloom Filter False Positive Rate Comparison.  
process. If after completing this process, the node does not find the next hop for the packet, the packet is dropped.
## 3 Data and Preprocessing
### Principal Component Analysis  
The purpose of conducting principal component analysis is similar to the purpose of feature selection, i.e., to find a smaller subset of features to improve prediction performance. Unlike the FS method, dimensionality reduction does not preserve the original features but instead transform features from high-dimensional space to new, lower-dimensional space. We implemented dimensionality reduction using the principal component analysis (PCA) method. PCA is a statistical procedure that uses an orthogonal transformation to convert a set of observations of possibly correlated variables into a set of values of linearly uncorrelated variables called principal components. The new feature set is a linear combination of these principal components and is used to build a new feature matrix.
## 1 Introduction
proposed the AOR method in [30], which is an extension of the SOR by using two parameters to speed up convergence, though the complexity of AOR is slightly higher than SOR; however, its performance can be significantly improved. To obtain a reasonable computational load, the Chebyshev acceleration uses the extension of the extrapolation acceleration method to accelerate convergence and reduce complexity [31]. In light of the above, to achieve a good trade-off between BER performance and complexity load, we propose a two-stage receiver for the MU M-MIMO systems, called Chebyshev-accelerated over-relaxation (CAOR) detection. The first stage of the receiver consists of setting each parameter of the AOR method [30] and using its algorithm to produce the rough initial estimate outputs, and then submitting those initial estimates of symbol detection and the AOR parameters to the second stage. In the second stage, the Chebyshev acceleration is conducted successively using the recursive relationship of the Chebyshev polynomials. It is noteworthy that, to render the estimated parameters more thoroughly, unlike the conventional iterative algorithm, this method provides Chebyshev algorithm calculation through AOR's initial estimated output and parameters to produce more precise and fast signal detection. Conducted simulations show that the proposed two-stage detection scheme, with a modest computational load, can provide superior performance compared with most iterative detection methods, especially in uplink MU M-MIMO scenarios. The rest of this paper is organized as follows. Section 2 introduces the system model employed in this paper. A review of some conventional iterative schemes and a new two-stage receiver based on the AOR iterative algorithm and Chebyshev acceleration are addressed in Section 3. Simulation results and computational complexity analysis are provided in Section 4 to verify the proposed approach. Section 5 provides the concluding remarks to summarize the paper.
## 2 PCMs: Basic Characterization
### PCM Applications
The use of PCMs is attractive in the automotive industry for battery thermal management, mainly in hybrid and electric vehicles. High and low temperature can influence the battery performance and in more critical cases, overheating of the battery can damage or even cause failure in such a component, causing safety risks [44]. The prevention of battery failures due to overheating is also crucial in electronic equipment. In this context, work [11] has outlined the application of PCMs in such equipment in order to increase the heat dissipation capability. Textileapplications of encapsulated PCMs include clothing for thermal comfort in hot and cold environments, space suits, sportswear, medical applications, shoes, and accessories [45]. Heat storage with PCMs also represents an attractive option in solar dryers for agricultural and food products [46]. Additional examples of PCMs applications are in medicine, including hot-cold therapies, food conservation, and transportation [16].
# Routing Algorithm Based on Trajectory Prediction in Opportunistic Networks
## 5 Conclusions  
The opportunistic network has the characteristics of topological dynamics and bandwidth first. The good routing protocol is the primary problem of constructing the opportunistic network, and it is also a hotspot and a difficult point of research. This paper proposes a routing algorithm based on trajectory prediction (RATP). The RATP algorithm uses the Gaussian process to calculate the probability of the node's future time velocity by analyzing the historical trajectory characteristics of the node. According to the predicted location information, the candidate node metric value is calculated and the node with the smaller metric value is selected as the data forwarding node, which effectively reduces the packet loss rate of the boundary and avoids excessive consumption of the edge node. The simulation results show that compared with other algorithms, the algorithm has higher transmission success rate, and the transmission delay and routing overhead are significantly reduced.  
In future work, first of all we hope to realize the position prediction algorithm and routing protocol in practical applications, and verify the effectiveness of the prediction algorithm and routing protocol in this paper by using real application scenarios. Secondly, we hope to consider the constrained factors of more nodes, so as to select a better forwarding node to achieve higher routing performance.  
Conceptualization, Methodology, Analysis, Investigation, Writing--original draft preparation, Writing--review and editing, Visualization, P.Z., L.W. and J.W.; Supervision, Project Administration, Funding Acquisition, M.Z. This research was funded by the National Natural Science Foundation of China (No.61572526). The authors declare no conflicts of interest.
# Mechanically Reconfigurable, Beam-Scanning Reflectarray and Transmitarray Antennas: A Review
## 4 Feed Movement
### Feed Displacement on Partially Illuminated Apertures  
There is a tradeoff between low phase aberration and high scan coverage when it comes to choosing the F/D ratio. Although some techniques were introduced to increase the scan range of RA, achieving a wide scan coverage is still difficult when using fully illuminated apertures. One method to address this issue is to use bigger reflectors for which different portions are used in order to create beam collimations toward different angles [54]. Indeed, using structures such as spheres or the parabolic torus [57] may increase the scan coverage. This is easily realizable in RAs since the phase of each unit cell can be simply controlled.  
Benefitting from its spherical symmetry, the spherical reflector can provide a wide scan coverage by partially illuminating different parts of a perfectly symmetrical reflector surface. Therefore, spherical reflectors are suitable candidates for high-gain applications with wide-angle beam scanning [55]. The phase distribution over the aperture of a planar RA can be designed to be equivalent to that of a spherical reflector. An RA with a spherical phase distribution was studied in [56] and the optimum feed position was obtained by analyzing the phase error. By illuminating only a small part of the aperture for each beam  
Figure 9: (**a**) Schematic of bifocal reflectarray antenna. (**b**) Scanned gain patterns of single and bifocal reflectarray designs (Reprinted with permission from [49]).  
angle, the effect of spherical aberrations decreased. In this manner, an RA was designed demonstrating a gain of 30 dB, elevation coverage of 30\({}^{\circ}\) and an illuminated aperture size of 15\(\lambda\) for 2D beam scanning. Due to having lower phase aberrations, parabolic torus reflectors can achieve better scan ranges compared to their spherical counterparts. An offset parabolic-torus phase RA was designed in [57], where the offset-fed structure removed the feed blockage. Using this technique, an RA was designed at the Ka-band with a scan coverage of 40\({}^{\circ}\). The performance metrics of some state-of-the-art RAs and TAs using feed movement are summarized in Table 3.
###### Abstract  
Conventional binders cannot meet the current performance requirements of asphaltic pavements due to increase in traffic volumes and loads. Nanomaterials, due to their exceptional mechanical properties, are gaining popularity as bitumen modifiers to enhance the performance properties of the asphaltic concrete. Carbon Nanotubes (CNTs) are one of the most widely used nanomaterials because of their strength properties, light weight, small size, and large surface area. CNT addition results in improved substrate characteristics as compared to other modifiers. Due to high length to diameter ratio, dispersion of CNTs in bitumen is a complex phenomenon. In this study, dispersion of CNTs in bitumen was carried out using both dry and wet mixing techniques, the latter was selected on the basis of homogeneity of the resultant asphalt mixture. Scanning Electron Microscopy (SEM) was used to check the dispersion of CNTs in binder while Fourier Transform Infrared Spectroscopy (FTIR) was carried out to ensure the removal of solvent used for wet mixing. Conventional bitumen tests (penetration, softening point, and ductility), dynamic shear rheometer tests, rolling bottle tests, and bitumen bond strength tests were employed to check the improvement in the rheological and adhesion properties of bitumen while wheel tracker test was used to check the improvement in resistance against permanent deformation of asphalt mixtures after addition of CNTs. Results show that CNTs improved the higher temperature performance and permanent deformation resistance in both binder and mixtures. Improvement in bitumen-aggregate adhesion properties and moisture resistance was also observed.  
Carbon Nanotubes (CNTs); wet mixing; bitumen; homogeneous dispersion; rutting; adhesion
# Influence of Soil Parameters on Detecting Voids behind a Tunnel Lining Using an Impact Echo Method
## 3 Experimental Study
### Soil Density Alteration
where \(u_{0}\) is the displacement amplitude and \(a\) is the affecting area of the impact load. The potential energy \(W_{pot}\) and kinetic energy \(W_{kin}\) can be expressed as [31]:  
\[ \begin{array}{l}W_{pot}=\frac{32\pi Du_{0}^{2}}{3a^{2}}+\frac{k\pi u_{0}^{2}a ^{2}}{6},\quad D=\frac{Eh^{3}}{12(1-\
u^{2})}\\ W_{kin}=\frac{m_{0}^{2}}{10}\end{array}  \tag{6}\]  
where \(E\), \(\
u\), \(m\) and \(h\) are the elastic modulus, Poisson's ratio, mass and thickness of the plate, respectively. By introducing the principle of energy equivalence, the equivalent mass and stiffness can be obtained. Finally, the first order of the local mode frequency can be calculated using:  
\[f_{0}=\frac{1}{2\pi}\sqrt{\frac{192D/a^{4}+3k}{1.8 ph}}, \tag{7}\]  
where \(k\) is the equivalent supporting stiffness given to the plate by the soil. For the laboratory test, \(E=3.2\times 10^{10}\) N/m\({}^{2}\), \(h=0.05\) m, \(a=0.25\) m, \(\
u=0.2\), \(\rho=2300\) kg/m\({}^{3}\) and \(k=4\times 10^{8}\) N/m; therefore, \(D\) was calculated to be \(3.472\times 10^{5}\) N\(\cdot\)m; and finally the resonance frequency was calculated to be \(1496\) Hz, which was close to the tested dominant frequency. The resonance frequency is mainly determined by the plate and soil. The void can only affect the amplitude but not the frequency of the resonance. The explanation matched with the test results. With increasing density, the dominant frequency amplitude decreased. For case D1, peak values around \(800\), \(1100\) and \(2800\) Hz could also be observed. The energy was concentrated at certain frequencies compared to the other two cases. This was caused by the looser concrete-soil contact, which induced a more complex wave reflection at the interface. In addition to Fourier spectrum analysis, wavelet transforms (WTs) were employed to perform time-frequency domain analysis, which provided more valuable visualised information. For the non-stationary signals, i.e., responses induced by impact loads, the frequency domain representation changes over time. Time-frequency domain analysis offers advantages over the frequency or time domain signal representations. Figure 9 illustrates the time-frequency spectra for three density cases, where the energy distribution of the acceleration responses can clearly be observed. With increasing density, the energy attenuation duration became shorter and the amplitude became smaller. Similar to the Fourier spectrum, peak values around \(800\), \(1100\) and \(2800\) Hz were observed more clearly for case D1 than the other two cases. Moreover, the vibration energy above \(2800\) Hz had a short duration, while the energies around \(800\) and \(1100\) Hz had a longer duration. Figure 8: Acceleration frequency spectra for different density cases.