esa-sceva/satcom-chunk-collection huggingface dataset:
## 1 Introduction  
With the soaring global demand for information increasing, satellite networks have become a powerful complement to terrestrial communications due to their wide coverage. As a technology expansion and integration of traditional aerospace and communication fields, the satellite Internet can easily achieve three-dimensional full coverage of land, sea and air including the poles and provide better support for the application of the Internet of Everything. There have been some high-throughput GEO projects [1, 2, 3] such as IPSTAR, Spaceway-3, \"Zhongxing\" and \"Asia-Pacific\" to meet the growing communication needs. However, GEO satellites have inherent shortcomings such as limited orbital resources, large delay, and high cost. Therefore, the deployment of LEO satellite constellations has gradually become an essential means to achieve the globalization, broadbandization and commercialization of communications [4].  
In recent years, the world's aerospace science and technology powers have proposed or implemented their own LEO satellite Internet constellation plans [5], which provides broadband Internet access service for areas with limited telecommunication infrastructure by launching hundreds or thousands of satellites. The satellites use phased array and high-throughput technology to provide ground users with ultra-low-latency broadband access with hundreds of megabytes of bandwidth. However, due to the small size and low power of LEO satellites, their onboard resources are severely limited. With the explosive development of large-scale LEO constellations, the competition for resources such as spectrum has become more intense. Meanwhile, due to the fast movement of LEO satellites, the sub-satellite coverage area and the electromagnetic environment change drastically, making both the available communication resources and terrestrial user requests extremely dynamic and complicated. Furthermore, according to the International Telecommunication Union (ITU), it is necessary for LEO satellites to control the interference to the GEO communication system within an acceptable level [6]. All the above constraints make it rather challenging to schedule the access resources of LEO satellites efficiently.  
By flexibly controlling the antenna direction, frequency band, power and communication time slot, beam hopping (BH) can realize the on-demand allocation of communication resources for dynamic user requests, which is an effective way to solve the above challenges. So far, many scholars and enterprises have carried out a lot of research on beam hopping.
# Eco-Friendly Metadome-Antenna Innovations for Wearable Millimeter Wave Radar Sensing
## 2 Materials and Methods
### Design of the Metasurface-Based Radome
This aspect of the design process relies not only on specifications provided in datasheets of the machine (milling machine in this work) and/or the materials but also on the designer's experience and understanding of the mechanical properties of the selected materials  
The metasurface unit-cell geometry (Al cross on PP slab) and dimensions, as well as the simulation set-up using Floquet ports and master-slave boundary conditions, are shown in Figure 1. It is remarkable that, according to the retrieved transmission and reflection coefficients for both TE- and TM-polarized incident plane waves (see Figure 2), very high transmission and very low reflection is achieved in the target band (24.05 GHz-24.25 GHz), as intended. Figure 1: Metaradome: (**a**) Unit-cell and optimized dimensions on PP, (**b**) Simulation Set-up. The operation of the metasurface can be explained on the basis of a simple LC parallel circuit. The metallic strips have an inductive behavior (either seen from the point of view of a TE-polarized or TM-polarized incident plane wave), while the dielectric between the strips gives rise to a capacitive effect, which can be relatively weak if the distance between the strips is large or, more relevant, if it is reduced. A parametric analysis, to clarify the metasurface behavior and to identify the basis on which the optimal design values have been obtained, reveals the following: the lengthening of ls (and, therefore, of p), causes a downward shift in the operating frequency at which reflection (S\({}_{11}\)) is minimum and transmission (S\({}_{21}\)) is maximum, due to its direct effect on an increase of the equivalent inductance. On the other hand, increasingWs results in a reduction of the equivalent inductance, which not only shifts the operating frequency upwards, but also slightly worsens the transmission (reducing S\({}_{21}\)) and reflection (increasing S\({}_{11}\)), because it also slightly modifies the capacitance by increasing it. Finally, as might be expected, reducing the thickness (h) of the dielectric, in addition to causing the metasurface to act as a radome (metaradome) at a higher frequency, improves its operation by reducing reflectivity (lower S\({}_{11}\)) and, consequently, increasing transmission (higher S\({}_{21}\)), making it more transparent. Taking all these considerations into account, in addition to the available PP thicknesses, the optimized design of Figure 1 has been achieved. The angular stability is a key property for a metasurface usable as a radome. According to Figure 3, the metaradome (MTR) is fully stable under oblique incident TE-polarized plane waves (up to \(\theta=48^{\circ}\)) and highly stable for TM-polarized plane waves (up to \(\theta=26^{\circ}\)), considering both transmission and reflection coefficients in the target band. Figure 2: Metaradome: properties (**a**) transmission coefficient, (**b**) reflection coefficient.
# Energy Efficient Dynamic Symmetric Key Based Protocol for Secure Traffic Exchanges in Smart Homes
## 1 Introduction
### Security Goals and Requirements  
The numerous vulnerabilities, threats, and attacks in smart home networks might impede the adoption of smart home networks. Therefore, strong security techniques should be implemented to protect the transmitted as well the stored data in smart home devices. To achieve this, an ideal authentication protocol should strive to offer the following security and privacy features:  
Backward key secrecy: Suppose that an adversary has some access to the current session key. This backward key secrecy ensures that an attacker is unable to derive the session key utilized for the previous communication session based on the current session key.  
Forward key secrecy: It should be computationally infeasible for the adversary equipped with the current session key to compute the session key for any subsequent communication [8].  
Mutual authentication: Before the communicating entities can initiate any message exchanges, they should verify the legitimacy of each other.  
Anonymity: During the authentication, key agreement, and communication processes, an attacker should be incapable of discerning the real identities of the communicating parties.  
Unlinkability: It should be cumbersome for the adversary to relate the captured messages to any of the past as well as future messages emanating from the same communicating entities.  
Robustness against attacks: A truly secure protocol should protect against conventional smart home attacks. These include denial of service, impersonation, man-in-the-middle (MitM), session hijacking, packet replays, and eavesdropping attacks.
## 8 Performance Evaluation
### Handoff Overhead
#### 8.2.2.2 Tunneling Cost versus Packet Arrival Rate  
From Figure 24, it can be seen that the tunneling cost of both DLoWMob and LoWMob scheme increases linearly as the packet arrival rate increases. This is because the tunneling cost is directly proportional to the packet arrival rate. However, the increase in the tunneling cost for the LoWMob scheme is more, as compared to DLoWMob; because, comparably with DLoWMob, LoWMob involves more number of hops from GW to the MN. The comparison with the proposed scheme also shows that the tunneling cost is less as compared to HMIPv6. This is because in HMIPv6, tunneling cost for a packet is equal to the size of an IPv6 header [33].  
Figure 23: Speed vs. LU cost.  
Figure 24: Tunneling cost vs. packet arrival rate.
# Body-to-Body Cooperation in Internet of Medical Things: Toward Energy Efficiency Improvement
## 1 Introduction  
Currently, the Internet of Things (IoT) is one of the most powerful communication technologies of the 21 st century. In the IoT environment, most of the electronic devices in our daily life will be a part of the Internet because of its communication and computing abilities. One of the important applications of IoT is healthcare. In healthcare technologies, the Internet of Medical Things (IoMT) requires several kinds of inexpensive sensors, wearable or implanted, which allow elderly people to enjoy recent advances in medical healthcare anytime, anywhere' [1; 2; 3; 4].  
Wireless body sensor network (WBSN) technologies are one of the most powerful technologies that could be utilised in the IoMT system [5]. WBSN technology comprises a group of low-power and lightweight devices with a transceiver which are used to observe the vital signs of the human body. Every sensor in WBSN is capable of gathering physiological signals, such as electrocardiogram (ECG), electroencephalogram (EEG) and movement, and sends the gathered signals to the coordinator node (CN) via a wireless medium or human body channel (HBC) for further analysis and inspection [6].  
WBSN paradigms are capable of providing long-range healthcare monitoring of humans without constraining their mobility or activity. These paradigms are used to create an intelligent and cheap healthcare-monitoring system and are used for diagnostic procedures [7].
## 3 Experimental Investigation
### Experimental Results  
Under the application of increasing displacements, the sample first stretches uniformly, then it undergoes necking at an indeterminate region (as in Figure 4a) and finally, the failure occurs in the region of the necking (as in Figure 5a).  
The experimental force-displacement diagrams of all samples were recorded and are reported below in the discussion of the experimental results. The following significant parameters were extrapolated from these diagrams:  
Figure 4: Sample 11 (**a**) just before failure; (**b**) after cohesive failure.  
Figure 5: Sample 7 (**a**) at failure; (**b**) after adhesive failure.  
Figure 3: Test setup.  
* \(F_{max}\), which is the maximum force that the sample withstands
* \(d_{F_{max}}\), which is the elongation of the sample for \(F_{max}\)
* \(d_{u}\), which is the elongation of the sample at failure, calculated as the elongation corresponding to a force reduced of 5% with respect to \(F_{max}\).  
The values of these parameters for all of the tested samples are shown in Tables 2-7 together with the type of failure exhibited by the sample. The sample failures are classified as follows [6]:  
* Cohesive failure is when the failure occurs only inside the elastomer due to the tensile stresses. This failure produces a ruptured surface within the elastomer with tear damage, as it can be seen in Figure 4b. In samples that undergo this type of failure, the deformation and strength properties of the elastomer are completely exploited before the occurrence of adhesive failure.
* Adhesive failure occurs when the failure involves the bonding surface between the steel and elastomer and results in a detachment, without any damage to the elastomer component. It results in the elastomeric layer detaching from the steel layer (Figure 5b) and occurs when the bond strength between the two layers is not sufficient to attain cohesive failure.
* Mixed failure is manifest by intermediate behaviors (Figure 6b) between the cohesive and adhesive failures described above. In this case, some portions of the sample show rubber detached from steel, and other portions show tear damage.
# A Field Investigation on Vortex-Induced Vibrations of Stay Cables in a Cable-Stayed Bridge
## 5 Conclusions  
This paper reported a field study to monitor the vortex-induced vibrations (VIVs) of stay cables of a cable-stayed bridge. The characteristics of the wind and cable responses and their correlations were investigated and analyzed. An estimation method for predicting the vibration modes of VIVs was proposed and validated by the field-measured data. Based on the field-monitoring study, some conclusions can be drawn as follows.  
The mean wind speeds on the investigated bridge are mostly less than 15 m/s for the investigated period. The mean wind speeds in the incoming flow and the wake flow, which are measured respectively on the upstream and downstream sides of the mid-span bridge section, are found close. In addition, there is a small phase difference for the wind direction, but a notable difference for the turbulence intensity between these two sites.  
The VIVs of stay cables frequently occur at low wind speeds and are characterized as being of high-frequency and multimode when the wind is nearly perpendicular to the cable plane and has a low turbulence intensity. As for the multimode VIV, the larger vibration amplitudes are mainly located in the region next to the reduced velocity of five. The relationship between the maximum vibration amplitude and the mean wind speed could be expressed by a function that agrees with the measured data.  
Figure 19: Comparison of measured vibration modes and estimated vibration modes. (**a**) Measured vibration modes versus estimated results in July; (**b**) Measured vibration modes versus estimated results in August.  
The estimation method for the participative vibration modes was presented and validated by the field-monitoring data. The results showed that the estimated vibration modes are consistent with the measured vibration modes.  
Conceptualization, W.-L.C. and H.L.; methodology, W.-L.C., H.L. and D.G.; investigation, D.G. and S.L.; writing--original draft preparation, W.-L.C. and D.G.; writing--review and editing, W.-L.C. and D.G.; supervision, W.-L.C. and H.L.; project administration, W.-L.C. and H.L.  
This research received no external funding.  
This research was funded by the National Natural Science Foundation of China (51578188 and 51722805) and the Fundamental Research Funds for the Central Universities (HIT.BRETIV 201803).  
The authors declare no conflicts of interest.
## 3 Results and Discussion  
### Characteristics of Blackcurrant Pomace  
The moisture content in fresh blackcurrant pomace was 57.3% (Table 1). This is the typical water content of pomace obtained from berries treated by enzymatic processing. Other studies have reported moisture content in treated berry pomaces from 51.6% to 62.2% [29]. Enzymatic treatment increased the efficiency of juice pressing. Pectinases loosen fruit tissue by degrading pectin, while hemicelllusses break down and hydrolyzate xylans, galactans, mannans and arabans. However, less moist pomace can be obtained in combination with an advanced hydraulic piston-cylinder press. Because of the high moisture content, the water activity (aw) value was also high (Table 1), which means that the pomace is highly susceptible to microbial spoilage, and rapid transfer to further processing is necessary.  
When extracting with alcohol-containing solvents, especially at low pH, it is important to analyze the protein content in the matrix because it can bind to polyphenols and precipitate during the process. The protein content of the pomace analyzed was low, about 5.2% of fresh weight, which allowed the extraction to proceed correctly. In other studies, the protein content of blackcurrant pomace was between 4.0 and 8.1% of fresh weight [1; 29].  
The color of blackcurrant pomace was dark red/purple, indicating its richness in anthocyanins. Fragments or whole seeds were visible in the pomace mass. However, blackcurrant fruits contain many seeds, which are not convenient to remove during extraction. Similar color properties of blackcurrant pomace were found in another study [29].  
The anthocyanin content in the blackcurrant pomace studied was 853.2 mg per 100 g fresh weight. The high content of anthocyanins in berry pomace is due to their accumulation mainly in the skin. Therefore, they are a valuable by-product of the food industry with the possibility of further uses, such as pigment extraction or food coloring. According to chromatographic analysis, delphinidin-3-O-rutinoside was the predominant anthocyanin (45.5% of total anthocyanins) (Table 1). Cyanidin-3-O-rutinoside and delphinidin-3-O-glucose accounted for a similar share, 24.1% and 23.5%, respectively. The smallest share of all anthocyanins was represented by cyanidin-3-O-glucose (7.0%). The literature shows different proportions of these four major anthocyanins in blackcurrant fruits and pomace [12; 30]. However, these four anthocyanins account for 97% or more of the total anthocyanin content [31]. It should be remembered that the differences in results depend on the blackcurrant variety, the agronomic method and place of cultivation, the year of harvesting and the technological processes used during juice pressing [32].
## 1 Introduction
An approach to implement the dual-band dual-CP array with a single-layer substrate is also reported in [15]; dual-CP operation is achieved by directly connecting two patches operating at 2 different frequencies and different polarizations. However, the maximum element spacing in high frequency is limited to avoid grating lobes in large scanning angles, which means that the element spacing in low frequency is very small under the same aperture, with the same element number for high- and low-frequency elements as shown in [14]. The gain of the low-frequency antenna array is thus sacrificed. Furthermore, the strong mutual coupling and poor isolation due to the small element spacing will greatly decrease the capability of wide-angle beam scanning in the low-frequency band. Ensuring a wide-angle beam scanning capability for both high- and low-frequency band operation simultaneously and arranging all the elements appropriately on one single-layer substrate is never a trivial task, especially under the limit of a special high-low-frequency ratio. In this paper, a dual-band, dual-CP, shared-aperture phased array antenna is proposed for direct-to-cellular communications. The proposed shared-aperture array is composed of two separate antenna arrays with single-layer structures, viz., a 16 \(\times\) 16 Tx antenna phased array with left-handed circular polarization (LHCP) and an 8 \(\times\) 8 Rx antenna phased array with right-handed circular polarization (RHCP), respectively. To meet the demands of antenna element miniaturization and low profile of satellite payload antennas, radiation elements are optimized using ceramic substrates with appropriate dielectric constant and optimum interelement spacing on one single layer, to ensure a wide-angle beam scanning capability for both high- and low-frequency band operation without a grating lobe. To the authors' best knowledge, it is the first time to achieve the large-angle beam scanning capability with \(\theta\geq 50^{\circ}\) in the elevation plane for S-/C-band simultaneously in one single-layer shared-aperture array based on high dielectric ceramic antenna technology. This article is organized as follows. Section 2 describes the configuration and design principles of the proposed dual-band, dual-CP phased array and elements. Section 3 presents simulation results and experimental results. Section 4 shows the performance of the proposed antenna array compared with other related works. Finally, the conclusion is shown in Section 5.
# Highland Barley Replaces Sorghum as Raw Material to Make Shanxi Aged Vinegar
## 4 Conclusions  
In this study, HBV was made, using HB as the raw material, based on the process of SAV, a famous vinegar in China, in which sorghum is usually used as the raw material. The results showed that HB may be more appropriate than sorghum as the raw material, because the contents of starch and protein, the main components in brewing vinegar, were higher in HB. In addition, compared with SV, the acid and ester VFCs in HBV were superior.  
**Supplementary Materials:** The following are available online at [[https://www.mdpi.com/article/10.3390/app11136039/s1](https://www.mdpi.com/article/10.3390/app11136039/s1)]([https://www.mdpi.com/article/10.3390/app11136039/s1](https://www.mdpi.com/article/10.3390/app11136039/s1)), Table S1: VFCs in aged HBV and SV detected by HS-SPME/GC-MS.  
**Author Contributions:** Conceptualization, F.C.; data curation, formal analysis and visualization, H.Z.; investigation, resources and software, J.Z. and F.L.; methodology and validation, Y.Z.; writing--review and editing and funding acquisition, F.C. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{l l c c} \hline \hline  & \multicolumn{2}{c}{**VFCs**} & \multicolumn{2}{c}{**Concentrations (mg.L\({}^{-1}\))**} \\ \cline{3-4}  & & **HBV** & **SV** \\ \hline Acids & 3-Methyl- butanoic acid & 563.83 \(\pm\) 10.40 & 458.56 \(\pm\) 13.12 \\  & Hexanoic acid & 808.51 \(\pm\) 6.02 & 431.15 \(\pm\) 4.84 \\  & [R-(R*,R*)]-2,3-Butanediol & 248.85 \(\pm\) 3.43 & 1043.19 \(\pm\) 30.54 \\ Alcohols & 2-Furanmethanol & 411.11 \(\pm\) 7.15 & 747.36 \(\pm\) 10.15 \\  & Phenylethyl alcohol & 1578.52 \(\pm\) 34.31 & 2478.52 \(\pm\) 55.52 \\ Esters & 2-Furanmethanol acetate & 231.23 \(\pm\) 14.30 & 105.97 \(\pm\) 4.22 \\  & Acetic acid 2-phenylethyl ester & 1193.05 \(\pm\) 32.56 & 495.92 \(\pm\) 7.01 \\ Aldehydes & 3-Furaldehyde & 95.88 \(\pm\) 2.74 & 367.65 \(\pm\) 4.70 \\  & Benzaldehyde & 414.71 \(\pm\) 3.33 & 303.41 \(\pm\) 2.41 \\  & Benzeneacetaldehyde & 114.65 \(\pm\) 3.29 & 203.71 \(\pm\) 2.62 \\  & (E)-2-Octenal & 208.86 \(\pm\) 5.56 & - \\  & 2-Undecanal & 84.14 \(\pm\) 0.81 & 5.06 \(\pm\) 0.75 \\ Ketones & Dihydro-5-opentyl-2(3H)-furanone & 174.52 \(\pm\) 3.20 & 306.76 \(\pm\) 4.78 \\ Pyrazines & Tetramethylpyrazine, & 722.33 \(\pm\) 5.17 & 1038.16 \(\pm\) 11.43 \\ Others & 2-Pentadecyl-1,3-dioxepane & 30.31 \(\pm\) 0.49 & 221.92 \(\pm\) 4.89 \\  & Creosol & 146.03 \(\pm\) 4.26 & 50.82 \(\pm\) 1.99 \\ \hline \hline \end{tabular} Note: “-” means not detected by HS-SPME-GC-MS.  
\end{table}
Table 5: Summary of main VFCs in aged HBV and SV.
## 5 Simulation Results and Discussion
### Multiple Fault Detection and Isolation  
Multiple sensor FDI scenarios are presented as follows:  
* **Type a** and **Type b** fault at \(t=0.4\) s and \(t=0.8\) s,
* **Type b** and **Type c** fault at \(t=0.4\) s and \(t=0.7\) s,
* **Type a** and **Type c** fault at \(t=0.4\) s and \(t=0.6\) s,
* Three type faults occur simultaneously at \(t=0.4\) s, \(t=0.7\) s and \(t=1.2\) s.  
The FDI variable behaviors during multiple current sensor faults are shown in Figure 5-8. The fault detection flag \(f_{d}\) and isolation flags \(f_{a},f_{b},f_{c}\) change from '0' to '1' after the faults occurred. For two sensor fault scenarios, the isolation flag for healthy sensor remains '0', indicating that it operates normally.  
Figure 4: Simulation results for fault isolation of **Type c** fault in phase c (from top to bottom are three-phase current \(i_{abc}\), isolation variables \(f_{a},f_{b},f_{c}\) and FDI flags \(f_{d},f_{a},f_{b},f_{c}\)).  
Figure 5: Simulation results on simultaneous isolation of phase a and phase b fault.  
Figure 6: Simulation results on simultaneous isolation of phase b and phase c fault.