esa-sceva/satcom-chunk-collection huggingface dataset:
# A New Compact Octagonal Shape Perfect Metamaterial Absorber for Microwave Applications
## 3 Results and Discussions
### Analysis of Design Structure with Different Thickness of FR4 Substrate Materials  
Different thickness of substrate materials, for example, 0.8 mm, 1.6 mm, and 2.4 mm have been considered in the design structure. To observe the absorption, three different thicknesses have been utilized for proposed design. It is observed from Figure 7, the absorption values of the structure are 89.20% at 7.85 GHz, and 95.76% at 10.94 GHz, respectively, for FR4 substrate material with 0.8 mm thick. Similarly, the values of the absorption are 99.64% at 8.08 GHz, and 99.97% at 11.40 GHz, correspondingly for 1.6 mm thickness. Besides, absorption values are 92.88% at 8.07 GHz and 99.56% at 11.57 GHz, individually for 2.4 mm thickness of substrate material. The high absorption value are 99.64% at 8.08 GHz, and 99.97% at 11.40 GHz for 1.6 mm thickness of substrate material. Due to different thickness of substrate material, the absorption rate has been different at different frequencies.  
The thickness of substrate material with 1.6 mm has revealed the maximum peak. On the other hand, the minimum peak has been achieved from FR4 substrate material with 2.4 mm thickness.  
Figure 6: Absorption of design structure with polarization angle.
## 3 Experimental Results
### CO Detection Circuit  
Based on Figures 3, 7a and 8, a new CO detection system would be implemented using the NiSb\({}_{2}\)O\({}_{6}\) pellets and a DC electronic circuit. Its characteristics are: its operating concentration is into the interval of 5 and 300 ppm, its operating temperatures are 100 \({}^{\circ}\)C, 200 \({}^{\circ}\)C, and 300 \({}^{\circ}\)C, high sensitivity at 300 \({}^{\circ}\)C, economic fabrication and easy implementation. To operate the CO detection system at 300 \({}^{\circ}\)C and 50 ppm (or major), we propose the electronic circuit as Figure 9 illustrates.  
Observing Figure 9, \(R_{1}\), \(R_{2}\), \(R_{3}\), \(R_{4}\), \(R_{5}\), and \(R_{6}\) have values of 1 K\(\Omega\) (1000 \(\Omega\)), the sensor's resistance \(R_{s}\) was measured to \(\sim\)560 \(\Omega\) (Figure 8) and consequently, resistance \(R_{x}\) was calibrated to \(\sim\)560 \(\Omega\) (Equation (5)). The Wheatstone bridge is supplied by \(V_{cc1}\approx 5\) V. Both operational amplifiers are supplied by \(\pm V_{cc}=\pm 12\) V. The differential amplifier has unitary amplification. Finally, the comparator has its gain in the operational amplifier in an open loop, \(A_{ol}~{}=\) 10,000 (see Equation (10)).  
On the other hand, Figure 10 shows the electronic diagram of our DC supply voltage. The voltage source has an error of \(\pm\)0.2 V, high repeatability, low cost, and good precision. In the power supply, the transformer reduces the alternate current (AC) from 120 V to 18 V, the bridge diode transforms the alternate current (AC) to direct current (DC), the capacitors filter the electrical signal and devices, LM317 T, LM7812, and LM7912 regulate the current voltages, \(V_{cc1}\approx 5\) V and \(\pm V_{cc}=\pm\) 12 V. Notice that, \(V_{cc1}\) has a fine-tuning through the resistor \(R_{AF}\).  
Figure 8: Response of NiSb\({}_{2}\)O\({}_{6}\) pellets: Resistance vs. CO concentrations.
# Potential Possibilities of Using Peat, Humic Substances, and Sulfurous Waters in Cosmetology
## 3 Peat  
### General Characteristics  
Peat is one of the most important natural raw materials in Poland. This peloid is formed as a result of the incomplete decomposition and humification of plant remains in high-humidity conditions under the influence of humifying, anaerobic bacteria but also fungi, algae, or microscopic water creatures [10,11]. Peat is also named as turf (in Polish, \"borowina\") and the areas where peat occurs are called peatlands, bogs, mires, moors, or muskegs [12].  
Due to the lack of consistent terminology allowing for a clear definition of peatlands, it is difficult to determine their exact global area. The international terminology of wetlands and peat bogs may be unclear because different languages have common names with different meanings and there are different criteria for distinguishing peat from other types of biogenic sediments [13].  
The physical and chemical effects of peat in cosmetics depend on the content of active substances in this peloid [14]. Humic compounds (humic acids, fulvic acids, and humins) show high biological activity and are the basic group of active substances that are credited with the action of peat, attracting the greatest attention of researchers around the world.  
The potential use of peat in cosmetology is primarily related to the action of humic acids, including antimicrobial [15, 16, 17, 18, 19], anti-inflammatory [20, 21, 22, 23, 24], and antioxidant [25, 26, 27, 28], which has been demonstrated in the context of the treatment of various diseases. Modern knowledge regarding the health-promoting and cosmetic uses of peat is based mainly on the action of humic compounds, which constitute the main group of active substances. Unlike raw peat, the composition of which is variable and dependent on many factors, humic compounds can be precisely tested quantitatively and qualitatively [29].  
Comprehensiveness and combining several treatment methods are very important in balneological treatment. This allows for an enhanced improvement effect, thanks to the mutual interaction and complementation of various stimuli. Therefore, spa treatments often use a combination of peloids and medicinal waters [9].
# The State of Ethereum Smart Contracts Security: Vulnerabilities, Countermeasures, and Tool Support
## 4 Smart-Contracts Vulnerabilities and Countermeasures
### Vulnerabilities and Countermeasures
#### 4.2.11. Default Visibility  
Solidity has visibility specifiers, public, private, external, and internal, that control functions and variables' visibility from outside of the contract and if public is not set as the default. If a developer does not specify an internally-used function as private, that function could be called from outside the contract, which will lead to unexpected operation escalation.  
_Countermeasures_. It is a good practice to always determine specifiers and Solidity also generates warnings for functions without specifiers while compiling.
## 3 Results
### Optimizing the Services: Finding the Best-Suited Quantile Forecasts
The results include correction for projected battery cycling life reduction (relative to nominal) and PV curtailment. (SC = 100%), but the grid deviates from its scheduled profile in order to compensate the errors (which implies lower GC). On the other hand, for under-estimative forecasts (i.e., low quantile forecasts), there will be excess of PV power that is counteracted by means of PV power curtailment (i.e., lower SC), when the battery gets full. In the latter case, the MG is able to closely follow the scheduled grid power profile, yielding the highest values of GC. The highest performance (GC = 100%) is obtained with the AnEn\({}_{\tau=0.1}\) quantile forecast (that is, at the same time, the least accurate), and it outperforms NWP by 1.5%. In this section, we realized the advantage of the quantile forecasts, which give us the flexibility to \"choose\", to some extent, the desired direction of the bias (or forecasting error), in order to favor a given service. Using these results, we managed to improve the performance of the services (independently) to a certain extent, and we found the best combinations of scheduling-strategy + forecasting-method for each service (graphically seen in Figure 7). However, given that the best combination of scheduling-strategy + forecasting-method is different for each service, when we chose to optimize one service, what is the impact over the other services? Can we find a strategy that produces a good performance for all services? This question is tackled in the following section.
###### Abstract  
The Ocean and Land Color Imager (OLCI) on the Sentinel-3A satellite, which was launched by the European Space Agency in 2016, is a new-generation water color sensor with a spatial resolution of 300 m and 21 bands in the range of 400-1020 nm. The OLCI is important to the expansion of remote sensing monitoring of inland waters using water color satellite data. In this study, we developed a dual band ratio algorithm for the downwelling diffuse attenuation coefficient at 490 nm (\(K_{\text{d}}\)(490)) for the waters of Lake Taihu, a large shallow lake in China, based on data measured during seven surveys conducted between 2008 and 2017 in combination with Sentinel-3A-OLCI data. The results show that: (1) Compared to the available \(K_{\text{d}}\)(490) estimation algorithms, the dual band ratio (681 nm/560 nm and 754 nm/560 nm) algorithm developed in this study had a higher estimation accuracy (N = 26, coefficient of determination (R\({}^{2}\)) = 0.81, root-mean-square error (RMSE) = 0.99 m\({}^{-1}\) and mean absolute percentage error (MAPE) = 19.55%) and validation accuracy (N = 14, R\({}^{2}\) = 0.83, RMSE = 1.06 m\({}^{-1}\) and MAPE = 27.30%), making it more suitable for turbid inland waters; (2) A comparison of the OLCI \(K_{\text{d}}\)(490) product and a similar Moderate Resolution Imaging Spectroradiometer (MODIS) product reveals a high consistency between the OLCI and MODIS products in terms of the spatial distribution of \(K_{\text{d}}\)(490). However, the OLCI product has a smoother spatial distribution and finer textural characteristics than the MODIS product and contains notably higher-quality data; (3) The \(K_{\text{d}}\)(490) values for Lake Taihu exhibit notable spatial and temporal variations. \(K_{\text{d}}\)(490) is higher in seasons with relatively high wind speeds and in open waters that are prone to wind- and wave-induced sediment resuspension. Finally, the Sentinel-3A-OLCI has a higher spatial resolution and is equipped with a relatively wide dynamic range of spectral bands suitable for inland waters. The Sentinel-3B satellite will be launched soon and, together with the Sentinel-3A satellite, will form a two-satellite network with the ability to make observations twice every three days. This satellite network will have a wider range of application and play an important role in the monitoring of inland waters with complex optical properties.  
diffuse attenuation coefficient; Sentinel-3A OLCI; Lake Taihu; remote sensing 2017 9, 1246; doi:10.3390/rs9121246
## 4 Results
### Phase Two: Spatial Audio Localization and Background Noise Testing  
A two-way mixed ANOVA showed that these differences in localization times were also significantly different (\(F(7,175)=7.565\), \(p\leq 0.001\), \(\eta_{p}^{2}=0.232\)). Figure 8 shows the mean localization times for both experiment groups across all auditory events in Phase Two, which shows shorter localization times in the 3D audio condition (\(M=8.4\) s) than in the mono control condition (\(M=17.8\) s).  
Figure 7: Two-dimensional density plot of positional tracking data throughout Phase One for all participants. Arrows point toward the target audio objects outside of the plot area. Distance from origin to audio objects—1 (6.8 m), 2 (4.57 m), 3 (5.98 m), 4 (12.43 m), 5 (5.96 m), 6 (3.86 m), 8 (5.74 m). (a) Spatial audio condition; (b) Mono condition.  
A hierarchical linear model was used to analyze the effects background audio, SNR, and type of stimulus have on localization times within both the 3D audio and mono control conditions, the results of which can be seen in Figure 9. Inferential statistics reported a significant overall effect of background audio on the time taken to locate each auditory event for both groups: 3D audio (\(F(1,54.713)=15.243\), \(p<0.001\)) and mono audio (\(F(1,84)=10.476\), \(p=0.002\)). Auditory stimuli within the higher background audio level of \(-53\) LUFS (3D audio \(M=10.4\) s and mono audio \(M=20.9\) s) displayed higher localization times than those with \(-43\) LUFS (3D audio \(M=6.5\) s, mono audio \(M=15.4\) s). Further to this, the effect of SNR between background sounds and auditory stimulus was only significant for the 3D audio group (\(F(1,71.029)=5.206\), \(p=0.026\)), with the time taken to correctly locate auditory stimuli +10 LUFS above the background audio level (\(M=7.4\) s) being lower than those with no SNR (\(M=9.5\) s). However, the background audio and SNR interaction was not significant for the 3D audio group (\(F(1,71.729)=1.3586\), \(p=0.248\)). Finally, the type of auditory stimulus yielded a significant effect on the results of localization times for both groups: 3D audio (\(F(1,68.778)=5.545\), \(p=0.021\)) and mono audio (\(F(1,84)=4.930\), \(p=0.029\)), showing participants taking longer to locate social stimuli (3D audio \(M=9.5\) s, mono controls \(M=19.33\) s) than simple (\(M=7.3\) s, mono controls \(M=16.17\) s).  
Figure 8: Mean localization times for each audio condition across all auditory events in Phase two. The whiskers denote 95% confidence intervals.  
Figure 9: Estimated means data from hierarchical linear model, comparing the effect of background audio, signal-to-noise ratio, and stimulus type for binaural spatial audio and mono control groups. The whiskers denote 95% confidence intervals.
## 5 Discussion
### Other Controls  
In addition to the effect of the Coriolis force, bottom currents and centrifugal forces may be also important factors influencing the asymmetric development of levees [7].  
According to seismic data interpretations [69; 70] and flume-tank experiments [71], bottom currents flowing perpendicular to the channel can carry more sediments out of the channel at the flank located downstream of the bottom currents, enhancing the development of levees and more abundant bedforms at this side of the channel. Previous studies have suggested that the northward-flowing AAIW and DWBC are respectively responsible for the preferential development of levees and sediment waves on the northern (left-hand) sides of the main channel of Bounty Channel and the channels on the Bounty Fan [8; 14; 26; 37; 65; 72]. Given that the studied tributary channels C1 and C2 are situated within the water depths influenced by AAIW (Figure 1A), it is plausible to speculate that AAIW may also contribute to the preferential development of levees on the northern sides of the channels.  
In the Southern Hemisphere, centrifugal forces and Coriolis effects act together in left-turning channel bends and against each other in right-turning channel bends when viewed in the downstream direction [7; 67]. When the Coriolis and centrifugal forces are in opposition, it is confirmed that the dominance of one will depend upon the velocity of the turbidity current and the degree of channel curvature. Considering that centrifugal forces mainly operate at channel bends and tributary channels C1 and C2 in the study area are relatively straight (Figure 7D-F), the effect of centrifugal forces on the asymmetric development of levees in this study may be limited.
## 7 Asset Recognition from Images and Populating the Database
### Virtual Tour Approach  
The approach followed to recognize items and their associated attributes in spherical photographs can be managed in two ways:  
* The first, which is essential, is for the images to be navigable in a virtual tour-style mode. The operator recognizes the assets in the image and must annotate separately the location where the asset recognized is located. This approach is very manual, and the operator always has to be aware of the position of the image inside the building complex while traveling along the trajectories.
* The second, which is optimal but not easy to implement, involves having the spherical images organized in a tree structure, in which the corresponding images are listed for each building environment in the agreed structure. This approach first requires that all images be organized in a directory structure and that the software platform used for such navigation allows the organization of the data, i.e., spherical views, with such a structure (Figure 31).  
This approach of navigating between areas of the building complex requires that each image be associated with the name or code of the area where that image was acquired in order to facilitate the association of items to different zones of the complex. For example, in the navigation phase for the recognition of items in the images, the operator who intends to observe the spherical image(s) acquired, for example, on the landing located on the third floor of staircase H in Building B of Complex A, will simply have to select the relevant directory in the data navigation platform, and not have to arrive at that data by force through a virtual journey starting from the entrance of the building complex to the required room. In this way, the technician who has to recognize the items can simply type in the name of the area of interest and immediately observe the images captured in that area.  
Figure 30: Navigation interface in the Benaco® [98] web platform. The example is taken from navigation tests in the “Modulo” building at the Faculty of Engineering of Brescia University.
## 4 Discussion
### Effect of Vertical Track Irregularities on Acceleration of Bridge  
As shown in Table 4, the acceleration of the bridge, unlike train acceleration, does not have a significant correlation with vertical track irregularity. The acceleration of a bridge increases when the excitation frequency of the train approaches the natural frequency of the bridge [29]. As shown in Table 7, the natural frequencies corresponding to the vertical vibration modes of the bridge are 4.81 Hz from the numerical model and 4.4 Hz from the measured vertical acceleration of bridge deck from the train test run. The excitation frequencies corresponding to the dominant wavelengths of the track-geometrical errors (45, 60, 70 m) are between 0.91 and 1.85 Hz at train speeds of 230 to 300 km/h. Even if we consider the effect of the mass of the train on the natural frequencies, they are far from each other, and therefore, it is reasonable that long-wavelength track irregularities do not affect the acceleration of the bridge. Rather, what does affect bridge acceleration is the excitation frequency determined by the bogie distance and axle distance of the train [7]. However, this dynamic behavior of the bridge due to the excitation frequency of the train should be validated at the design stage [2].
###### Abstract  
A simulator plays an important role in network protocol research, as it enables researchers to develop protocols more flexibly. Many simulators have been developed to support research in this field, including NS-2, NS-3, OPNET, OMNeT, and Cooja. Although, as a research support tools, NS3 and Cooja have already been equipped with an Internet of things (IoT) module, their support for research on IoT centralized scheduling is still limited. Therefore, this study is aimed to develop a tool for IoT centralized scheduling research, where the IoT technology is based on the IEEE802.15.4e time synchronized channel hopping (TSCH) standard. The tool is called the TSCH Link-Scheduling visualization and data processing (TLS-VaD). The results of validity tests show that TLS-VaD works well; therefore, this tool can be used in the performance measurement of centralized scheduling algorithms on TSCH networks. As an example of the application, this research used TLS-VaD to test the performance of three scheduling algorithms: Iman Ramli Bursty Transmission Scheduling Algorithm (IRByTSA), first top scheduling algorithm (FTSA), and first leaf scheduling algorithm (FLSA). The test results using TLS-VaD shows that IRByTSA had better performance compared to FLSA and FTSA, because it saved more power and was able to generate scheduling decisions relatively quickly.  
Keywords:internet of things; IEEE802.15.4e TSCH; scheduling; algorithm; tool +
Footnote †: journal:
## 2 Related Work  
Load balancing methods can be categorized based on whether they have access to global information and the scope of route modifications, including global strategies, local strategies, and hybrid strategies, which combine both global and local approaches. For global strategies, decisions about on-board routing are made by incorporating information about the global network load state. In the case of local strategies, neighboring satellites are informed passively or actively about congestion states, and congestion avoidance is carried out based on the actual link conditions. Global strategies tend to have slow response times, time-sensitive global views, and high signaling overhead, while local strategies lack a global view and may fall into local optima. Hybrid strategies that combine global and local elements aim to leverage the advantages of both.
# Experimental Study on Heat Transfer Performance of Vacuum Tube Heat Collector with Thermal Storage
## 5 Conclusions  
The thermal behavior of a novel energy storage vacuum tube collector has been experimentally investigated. Paraffin has been proven to be a good choice for the application of solar storage, due to its easy workability, its melting temperature, its high latent capacity and its availability. The phase transition temperature of paraffin is 58 \({}^{\circ}\)C, which is suitable for night time application.  
The primary objective of this study was to develop the energy storage vacuum tube collector. Subsequently, the operation conditions of transition season and summer for the solar storage water system were studied. Finally, the inlet and outlet water temperature of the system were analyzed at different flow rates.  
Results obtained for the energy storage vacuum tube collector with different flow rates of HTF are summarized here.  
1. The paraffin phase transformation occurs on sunny days of the transition season and summer. It can be found that the maximum hot water temperature reaches 67 \({}^{\circ}\)C and 53 \({}^{\circ}\)C with the average solar irradiation amount of 672 W/m\({}^{2}\) and 615 W/m\({}^{2}\) respectively in summer. Solar radiation has a greater influence on the temperature of the heat collector than ambient temperature during the charging process.
2. The amount of heat absorbed by PCM in the daytime of the summer season reaches 3300 kJ and 2934 KJ with the average solar irradiation amount of 672 W/m\({}^{2}\) and 615 W/m\({}^{2}\) respectively in summer. It can also be concluded that, as the solar radiation increases, the heat absorbed by the PCM also increases.
3. The maximum temperature difference reaches 11 \({}^{\circ}\)C, 10 \({}^{\circ}\)C and 5 \({}^{\circ}\)C at flow rates of 25 L/h, 50 L/h and 100 L/h respectively. As the flow rate increases, the outlet water temperature of the U-type copper tube decreases. As the flow rate decreases, the temperature difference between the outlet water and inlet water increases, but the changing rate of temperature difference is becoming slower.
4. Due to the heat stored in the PCM, a uniform discharging process takes a long time which provides more comfortable hot water application.  
The presented work was supported by the Research Funds of Key Laboratory of Heating and Air Conditioning, The Education Department of Henan Province; National Natural Science Foundation of China (Grant No. 50776015) and National Natural Science Foundation of China (Grant No. 51606037).  
[PERSON] and [PERSON] conceived and designed the experiment; [PERSON] performed the experiments and analyzed the data; [PERSON] wrote the paper.  
The authors declare no conflict of interest.