esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Results
As the measured high current density was a result of the ions accumulated on the  
Figure 8: The cyclic voltammetry (CV) curves of (**a**) TRG, (**b**) S\(+\)C\(-\) and (**c**) S\(-\)C\(+\) cells at the various voltage scan rates (**d**) comparison of the capacitance responses of the TRG, S\(+\)C\(-\) and S\(-\)C\(+\) cells. electrode in a short period, the ions may not have had sufficient time to diffuse in and out of the deep region of the pores and, thus, reduced the accessible surface area, causing decreased capacitance [32]. Therefore, the value of the specific capacitance implies an accessible surface area at a specific current density. At a low current density (1 A/g), the capacitances of the S\(-\)C\(+\)(193.9 F/g) and S\(+\)C\(-\)(188.3 F/g) were much greater than that of TRG (43.1 F/g). This result indicates that the increased interlayer distances could increase the accessible surface area for the electrolyte. In the existing literature, most asymmetric supercapacitors are related to pseudocapacitors, which lead to a very large capacitance, which is greater than 200 F/g [34]. To the best of our knowledge, we are the first group to report surfactant intercalated asymmetric EDLC using ionic liquid electrolytes, resulting in a high capacitance of 193.9 F/g. Figure 9: The discharge current vs. time of the (**a**) TRG, (**b**) S\(+\)C\(-\) and (**c**) S\(-\)C\(+\) cells at various discharging currents. The energy density is obtained using the following equation [31; 32; 33]. \[\text{E}=1/2~{}\text{CV}^{2}=1/8~{}\text{Cs}~{}\text{V}^{2}\]  
Moreover, the power density (P) is deduced according to [32; 33]:  
Figure 3:0  
Figure 11 shows the Ragone plot which reveals the energy density of TRG, and the S+C\(-\) and S\(-\)C\(+\) cells as a function of power density. Usually, energy density drops with power density as a result of voltage decay and capacitance reduction at a high power density. As can be seen, the significant initial voltage drop (Figure 9a) and the small capacitance (Figure 10) of the TRG cell resulted in its low energy density of 15.3 Wh/kg at 1 A/g. In contrast, the S\(-\)C\(+\) and S\(+\)C\(-\) cells had similarly small voltage drops and large capacitances and, therefore, at 1 A/g, the S\(-\)C\(+\) and S\(+\)C\(-\) cells had energy density values of 67.8 Wh/kg and 64.7 Wh/kg, respectively. Moreover, compared with the S\(-\)C\(+\) asymmetric cell, the symmetric cell using TRGSE as both positive and negative electrodes, had a relatively lower energy density of 61.8 Wh/kg. However, with the increased current, the initial voltage drop of TRG became prominent and, thus, limited its energy density of 0.34 Wh/kg at 6 A/g. It was found that, at a current density of 18 A/g, the S\(-\)C\(+\)(36.8 Wh/kg) cell had a higher energy density retention compared to the S\(+\)C\(-\)(20.9 Wh/kg) cell, implying an intercalated ionic species effect on the performance of the EDLC cell. Figure 3:1 Ragone plot of the TRG, S+C\(-\) and S\(-\)C\(+\) cells. Figure 3:2 The capacitance density vs. current density of TRG, and the S+C\(-\) and S\(-\)C\(+\) cells.
# THBase: A Coprocessor-Based Scheme for Big Trajectory Data Management
## 1 Introduction
HBase is an open-source, distributed, non-relational database modeled after Google's Bigtable, which enables real-time random access support for big data in the Hadoop environment. HBase uses Region as the basic element of availability and distribution, and can achieve parallel access to Regions through Observer and Endpoint coprocessors. Compared to other distributed frameworks, HBase coprocessor can easily achieve the colocation between programs and data, thus effectively reducing data transmission cost. So we implement our massive trajectory data management schemes based on HBase coprocessor. Based on the consideration of reducing data transmission, and taking into account pruning, sort, and footprint factors, THBase proposes a segment-based data model and an MO-based partition model to store trajectories. To accelerate spatiotemporal query processing, it imports a local indexing structure for each Region through Observer coprocessor. Furthermore, we design certain maintenance strategies to ensure the colocation between Region and its corresponding index. On this basis, THBase designs node-locality-based parallel query algorithms by Endpoint coprocessor to reduce the data transmission overhead when querying. Our main contributions can be summarized as follows:  
* We propose a segment-based data model and an MO-based partition model, which provides effective support for massive trajectory data storage in HBase. * We introduce an Observer coprocessor-based local indexing framework, which provides efficient support for the spatiotemporal queries and achieves the colocation for index and the indexed data. * We propose Endpoint coprocessor-based parallel algorithms for processing spatiotemporal queries to improve query efficiency. * We evaluate our scheme with the dataset of ship trajectory, the experimental results verify the efficiency of THBase. Section 2 introduces the preliminaries about the trajectory data, the basics in HBase, and the related work. The overview of THBase is introduced in Section 3. The three main modules, T-table,L-index, and Query Processing Module, are described in Section 4, Section 5, and Section 6, respectively. Section 7 provides an experimental study of our system. Finally, we give a brief conclusion in Section 8.
## 5 Conclusions  
* Overall, BFP-MSCs seeded in the presence of Ti disks showed a proliferative rate and viability comparable to cells plated without disks.
* When plated on Kontact S (chemically etched surface) and Kontact N (blasted/etched surface) the number of living cells counted on disks was significantly higher compared to that of cells remaining under the disks.
* Once detached from Ti disks, BFP-MSCs retained their morphology and viability.
* Culturing on Ti disks preserved secretion of multiple cytokines and chemokines by BFP-MSCs. This is of relevance since other studies have shown that implant surfaces may enhance the release of some inflammatory molecules by immune cells.
* In the presence of Kontact N (blasted/etched surface) BFP-MSCs released significantly higher concentrations of G-CSF, compared to cells plated without disks and to cells plated on a smooth Ti surface and Kontact S surface.  
Further in vitro and in vivo studies are necessary to define the implant surface parameters able to assure their optimal release for a real improvement of dental implant osseointegration. However, these novel findings, bridging together medicine, stem cell biology, and material sciences, provide new knowledge regarding the interaction between Ti implants and BFP-MSCs. This approach will contribute to paving the way for novel therapeutic strategies and oral surgery applications.  
Conceptualization, V.D.; methodology, J.C.S.; investigation, A.P. and D.L.; data curation, P.F.; writing--original draft preparation, G.S. and D.A.; writing--review and editing, G.M. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The authors declare no conflict of interest.
# Computer Modelling of Heliostat Fields by Ray-Tracing Techniques: Simulating the Sun
## 2 Sun Position
### Time \(LCT\to UT\to GST\to LST\)  
Time of day is a key variable in many astronomical algorithms. The simplest way to define time of day is to divide Earth in 24 time zones with \(360/24=15\) degrees of longitude each, one for each hour, so time can be measured in the observer's local place (Local Time = LCT) and in Greenwich, UK (Universal Time = UT), the Earth's reference meridian. However, in astronomical calculations, sidereal time is preferred, where time is counted relatively to a celestial reference meridian, defined by a fixed point in space, the First Point of Aries (see [22] or other astronomy reference work for details).  
The time algorithm layer includes the following three tasks: convert local time LCT to Greenwich Time (UT), convert UT to Greenwich Sidereal Time (GST) and convert back to Local Sidereal Time (LST). Converting Greenwich universal time (UT) to Greenwich Sidereal Time (GST) (step 2) is a key part of the whole algorithm, involving the calculation of Julian day numbers, to calculate the number of elapsed days from some reference date [22].  
If \(\Psi\) is the local longitude, from \(-180^{\circ}\) to \(+180^{\circ}\) (measured from the Greenwich meridian), to convert LCT to UT time (step 1) just subtract \(\Psi/15\) integer hours (rounded to the nearest integer), and to convert GST to LST time (step 3) just add \(\Psi/15\) fractional hours. In both conversions, after the adjustment: (1) if hour is above 24, subtract 24 and add 1 day; (2) if hour is below 0, add 24 and subtract 1 day.
# Carbon Oxides Gases for Occupancy Counting and Emergency Control in Fog Environment
## 2 Materials and Methods
### Wireless Sensor Network  
There are mainly three types of devices involved in the system: ZigBee Coordinator, ZigBee Router and ZigBee End Device. In what follows, more details about those devices are presented.  
ZigBee Coordinator: The function of coordinator is to choose a channel and network identity (PAN ID), to maintain the entire network, to design security policies and to communicate with other devices. It is the beginning of the entire network and has the highest authority. Moreover, it is worth pointing out that only one ZigBee coordinator is needed for each ZigBee network.  
ZigBee Routter: The router stores routing protocol which is used for network data routing and data transmission.  
ZigBee End Device: The end device is a specific implementation of the data acquisition. It cannot forward the messages from one node to another.  
Those three devices mentioned above can be divided into two groups based on their functional integrities, including Full Function Devices (FFDs) and Reduce Function Devices (RFDs). FFDs can be worked as coordinator, router or terminal device, while the RFDs can only be used as end device. A FFD is capable of communicating with multiple RFDs or FFDs simultaneously, whereas a RFD can only communicate with one FFD. Although ZigBee can transmit signals over a kilometer by increasing the transmit power, its strength will weaken when travelling through obstacles like walls. Thus, a large scale of wireless sensor network should have routers, repeaters or other equipment to extend its network coverage.  
To illustrate the working principle of ZigBee, an architecture of WSNs in a building is displayed in Figure 1. One or more sensors can be installed in a single room, and each of them can only communicate with its nearest router. The router is placed along the corridor or within a room according to its signal overlay area, and it is able to send signals to its neighbor router or the coordinator. A coordinator transmits data to a computer by interfaces, then data is processed in the computing center for further analysis. Figure 2 presents a typical room from Data Analytics and Collaborative Computing (DACC) Laboratory [24] is equipped with sensor network devices, and each independent space has a sensor. Here it is necessary to remark that the number of required sensors depends on the size of the room and the range of sensing.
# Day and Night: Locating the General Practitioner's Panel after Hours
## 3 Results
### Case Studies
#### 3.2.3 Halifax Approach Comparison  
Each approach broadly exhibits similar behaviours as the number of facilities to be located increases, but it is also appropriate to compare how each approach performs  
\begin{table}
\begin{tabular}{l c c c} \hline \hline \multirow{2}{*}{**Approach**} & \multicolumn{3}{c}{\(p\) = 60, \(p^{\prime}\) = 36} \\ \cline{2-4}  & **Total** & **Difference** & **Percent Difference** \\ \hline Independent & 705,368 & 0 & 0\% \\ Sequential (RtA) & 706,736 & 1367 & 0.19\% \\ Sequential (AtR) & 705,633 & 265 & 0.04\% \\ Simultaneous & 705,578 & 210 & 0.03\% \\ \hline \hline \end{tabular}
\end{table}
Table 4: Halifax Total Cost (km per person).  
Figure 4: Minimum cost of \(p\) facilities for different ratios of \(p^{\prime}\) (specified in legend). Independent approach in the Halifax setting is shown.  
relative to each other. As expected, the independent approach has the lowest cost, and the simultaneous approach has a lower bound than the sequential approaches. This can be seen in Figure 5, where each series shows the percent increase in costs compared with the independent approach for five different scenarios. This is calculated with the formula (approach cost \(-\) independent cost)/independent cost.  
One trend that is apparent in Figure 5 is that each approach converges to the same cost as the number of after-hours facilities approaches the number of regular facilities. This makes sense when considering the data used for this case study. The demand at each node is considered to be the same during both the regular and after-hours time settings, so the differentiating factor between problems in each setting is the number of facilities being placed. If the number of facilities being placed is identical, then the problems being solved will be identical for these case data. This is not a phenomenon that would be expected if demand differs between time periods, and this is not expected to be observed in the third case study.  
The phenomenon of the independent approach providing the best cost followed by the simultaneous approach is consistent across each scenario. In some cases, the RtA approach yields lower costs than the AtR, but in most cases, the AtR approach is better. However, both are consistently worse than the simultaneous approach. Although the relative difference in total cost is small, the results are important as the most commonly used approach in practice, RtA, is consistently the worst.
## 3 Results
### Irradiation Sequence Analysis and General Overview of Nuclear Data Comparison  
In this section, the results from the irradiation sequence are presented. As can be seen from the neutron budgets in the previous graphs, the DTE2 reaction has the highest level of activity (Figure 14) and dose rates. Like in the after-irradiation analysis, rhodium exhibits the highest level of activity during irradiation, peaking at over 10 \(\times\) 10\({}^{10}\) Bq/g a couple of times, followed by less-active silver and gold. Interestingly enough, despite the rapid decay, gold remains quite active throughout the entire campaign. As stated in the previous niobium analysis section, it has the biggest discrepancy between the nuclear databases utilized. It is evident (Figure 15) that on every irradiation day, the EAF-2010 data library produced higher levels of activation. Surprisingly, the inversion of the activity trend is only seen at the very end of the last tritium campaign. FISPACT-2 gives a very different interpretation of Nb93m generation for the different data libraries. In the case of the EAF-2010 nuclear data library, radionuclide is produced mostly by Zr93 beta decay, while in TENDL-2021, its production is grounded in neutron excitation (n,n) reactions. Figure 14: Evolution of specific activities during the DTE2 campaign. Figure 13: Specific activities in yttrium after full irradiation. In the following tables (Tables 1 and 2), the numerical values of the results are presented for the activities and dose rates for different nuclear data libraries. Outside of niobium, some other cases also have significant differences in the obtained values. Gold's activity decrease is less in EAF-2010 compared to TENDL-2021 due to larger Au195 production, which is the most relevant isotope for a 1-year cooling period. There is also a noticeable difference in gold's dose rates. Initially, different estimations of Au198 cause these differences, but at longer cooling intervals, Au195 is the responsible isotope. While some uncertainties are present in the nuclear data, such as the cross-sections themselves, there are also uncertainties stemming from the selection of energy groups. Uncertainties also tend to increase with the increase in cooling times as more rare radionuclides show up, originating from the difficult decay schemes. Overall, the gold foil has the highest dose rate after the end of irradiation out of the investigated materials. The dose rates for all the foils fall into a range between 50 nSv and 1 pSv per hour after the end of irradiation. Therefore, it should not pose a high radiation exposure risk if care is taken.
## 3 Mathematical Modeling
### Dynamic Equations When the Launch Is Off  
As shown in Figure 1a, in the vibration isolation design, the distances between the top and bottom of the base frame and the spacecraft \(m\) are both \(d\), and the original lengths of the vertical springs \(k_{1}\) and \(k_{3}\) are both \(l\). When the spacecraft \(m\) is in its initial position, the two transverse springs \(k_{2}\) and \(k_{4}\) are at their original lengths, and the two vertical springs are perpendicular to the direction of the transverse springs. The damping coefficients of the four springs are \(c_{1},\ c_{2},\ c_{3},\ c_{4}\), respectively. \(x\) is the distance by which the spacecraft \(m\) deviates from its initial position. The kinetic energy \(K\), potential energy \(V\), and dissipation function \(D\) of the system are expressed as follows:  
\[K=\frac{1}{2}m(\dot{x}+\dot{y})^{2} \tag{1}\]  
\[V=\frac{1}{2}k_{1}\Big{(}\sqrt{d^{2}+x^{2}}-l\Big{)}^{2}+\frac{1}{2}k_{2}x^{2} +\frac{1}{2}k_{3}\Big{(}\sqrt{d^{2}+x^{2}}-l\Big{)}^{2}+\frac{1}{2}k_{4}x^{2} \tag{2}\]  
\[D=\frac{1}{2}c_{1}\bigg{(}\frac{x\dot{x}}{\sqrt{d^{2}+x^{2}}}\bigg{)}^{2}+ \frac{1}{2}c_{2}\dot{x}^{2}+\frac{1}{2}c_{3}\bigg{(}\frac{x\dot{x}}{\sqrt{d^{2 }+x^{2}}}\bigg{)}^{2}+\frac{1}{2}c_{4}\dot{x}^{2} \tag{3}\]  
The governing equation for vibration isolation obtained from the Lagrange equation is:  
\[m\ddot{x}+\bigg{[}(c_{2}+c_{4})+(c_{1}+c_{3})\frac{x^{2}}{x^{2}+d^{2}}\bigg{]} \dot{x}+\bigg{[}(k_{2}+k_{4})+(k_{1}+k_{3})\bigg{(}1-\frac{l}{\sqrt{d^{2}+x^{ 2}}}\bigg{)}\bigg{]}x=-m\ddot{y} \tag{4}\]  
Based on the above equation, it can be seen that the two vertical springs \(k_{1}\) and \(k_{3}\) have the same effect on the vibration isolation system, and the two transverse springs \(k_{2}\) and \(k_{4}\) also have the same effect on the vibration isolation system. For the convenience of subsequent analysis, let:  
\[\begin{cases}k_{1}=k_{3}=k_{v},\ c_{1}=c_{3}=c_{v}\\ k_{2}=k_{4}=k_{h},\ c_{2}=c_{4}=c_{h}\end{cases} \tag{5}\]  
Then, Equation (2) can be simplified as:  
\[m\ddot{x}+\bigg{(}2c_{h}+2c_{v}\frac  
According to reference [32], the parameter condition for achieving quasi-zero stiffness is \(k_{\text{\tiny p}}/k_{h}=d/(l-d)\). Define the stiffness ratio \(\alpha=k_{\text{\tiny p}}/k_{h}\), and length ratio \(\lambda=l/d\); then the condition for quasi-zero stiffness is:  
\[\alpha=\frac{1}{\lambda-1} \tag{7}\]  
For a general quasi-zero stiffness vibration isolation system, \(\lambda>1\). Define the vibration transmissibility \(T\) thusly:  
\[T=\frac{\left|\ddot{x}+\ddot{y}\right|}{\left|\ddot{y}\right|} \tag{8}\]  
Vibration isolation performance is evaluated by the vibration transmissibility \(T\): the smaller \(T\) is, the better the vibration isolation performance. In the subsequent study of vibration isolation performance, it is assumed that the base excitation is a simple harmonic excitation \(\ddot{y}=Acos(2\pi ft)\), where \(A\) is the excitation amplitude and \(f\) is the excitation frequency.
## 4 Numerical Simulations
### Analysis of Simulation Results  
As shown in Figure 10, the stress distribution of the steel corrugated plate is consistent with the load on the structure, gradually increasing with the excavation depth and symmetrically distributed along the midline. However, the stress increases at the two shear connectors, which ensures the common stress and coordinated deformation of the structure. The maximum Mises stress generated by the corrugated steel plates was 0.4 MPa, and the maximum Mises stress generated by the mold bag concrete was 0.1 MPa, which were both less than the control indexes of the respective materials, and the members were within the safe range. The hoop strain and radial displacement of the structure are very small. When the excavation depth of the shaft is not large, the pressure generated during pouring concrete is the most significant factor leading to the deformation of the structure.  
Figure 8: Schematic diagram of formula parameters.  
Figure 9: Schematic diagram of the formula parameters.  
There is a large difference in the stress distribution between the crest and trough of the steel corrugated plate (shown in Figure 11). The stress distribution in the trough remains constant along the panel annulus, and the peak is located at the weld to the end flange plate (on both sides). However, the stress distribution of the crest first increases and then decreases along the panel annulus, showing the word 'M'. Moreover, the stress at the crest is generally greater than that at the trough.  
Figure 11: Stress distributions of the steel corrugated plate: (**a**) Trough and (**b**) Crest.  
Figure 10: Distributions of stresses of (**a**) the steel corrugated plate and (**b**) the mold bag concrete (Unit: MPa).
# Hierarchical Gradient Similarity Based Video Quality Assessment Metric
## 2 Hierarchical Video Quality Assessment
### Visual Attention Similarity  
Representations in the visual cortex are known to be overcomplete. Visual attention models [19; 20] show that the human visual system is more sensitive to salient regions. The similarities of only the salient pixels are selected to evaluate the perceptual quality. Similar to [13], pixels are determined to be the salient pixels if their spatio-temporal gradient magnitudes are above a threshold in either the reference video or the distorted video. The threshold is defined to be the average of the \(k\)th largest gradient magnitudes in the prediction parts of the reference frame and the distorted frame, respectively. It should be noted that the salient pixel detection is different from the traditional salient region and salient object detection methods. The proposed method is designed specially for video quality assessment so as to put more emphasis on important pixels, in which the salient pixels are distributed dispersedly. However, the salient pixels are concentrated in regions in the ground truth of the traditional saliency detection.  
We denote the set of the salient pixels in \(P_{r}\) and \(P_{t}\) as \(\mathbf{C}_{r}\) and \(\mathbf{C}_{t}\), respectively. The union of \(\mathbf{C}_{r}\) and \(\mathbf{C}_{t}\)--denoted as \(\mathbf{C}_{r}\bigcup\mathbf{C}_{t}\)--is the set of the salient pixels selected to be processed. Furthermore, the averaging on the similarities of the salient pixels can be used to evaluate overall similarity. However, it may lose the changes of the visual attention, and cannot represent the degradation of the whole frame efficiently. Therefore, the similarity of the visual attention is introduced as  
\[S_{va}(\mathbf{P}_{r},\mathbf{P}_{t})=\frac{|\mathbf{C}_{r}|}{|\mathbf{C}_{r} \bigcup\mathbf{C}_{t}|}, \tag{5}\]  
where \(S_{va}(\mathbf{P}_{r},\mathbf{P}_{t})\) denotes the attention similarity between the prediction parts \(\mathbf{P}_{r}\) and \(\mathbf{P}_{t}\) which are decoupled from the reference frame and the distorted frame, respectively. The numerator \(|\mathbf{C}_{r}|\) denotes the number of salient pixels in the reference frame. The denominator \(|\mathbf{C}_{r}\bigcup\mathbf{C}_{t}|\) denotes the number of the salient pixels in the union set. The difference between the denominator and the numerator represents the newly increased salient pixels. Thus, the ratio between the denominator and the numerator represents the VA similarity. Since the salient pixels are detected as the pixels with high gradient magnitudes, the VA similarity is considered as the frame-level gradient similarity, as well as the visual attention similarity.