esa-sceva/satcom-chunk-collection huggingface dataset:
# Multilayered Network Model for Mobile Network Infrastructure Disruption
## 3 Proposal of Multilayered Network Model for Mobile Network Infrastructure Disruption
### WSN Layer
The LoRaWAN technology transfer rates range between 0.3 kbps and 50 kbps. Since LoRa technology assures very large communication distances for an extremely low bandwidth, the standard is suitable for applications where a reduced amount of data is transferred and the information collected from the sensors does not change rapidly over time. In [19], the authors present multiple applications of LoRaWAN technology for WSN with IoT, such as water quality monitoring, agriculture, underground sensor networks or smart city. LoRaWAN is therefore another suitable technology for MNM. Based on Zigbee, Bluetooth and WISA standards [20], several enhancements/related standards or products have been presented like the WirelessHART [21] and ISA 100.11a [22]. WirelessHART is an industrial control protocol that is extension of the Highway Addressable Remote Transducer (HART) communication protocol. It is designed to be reliable, easy to use, and interoperable protocol deployed in process control applications, alerting and monitoring systems. WirelessHART has low power consumption compared to ZigBee with higher security standards, and it can also establish large networks and can support different communication topologies [21]. However, while WirelessHART offers several features that complement its suitability in industry, it fails to offer appropriate solutions to facilitate interoperability. It is also not compatible with IP-based devices and the IoT [23]. ISA100.11a is a wireless network solution for IWSNs (Industrial WSN), developed by International Society of Automation (ISA). Like WirelessHART, it targets industrial applications in automation, process control and monitoring. It has the features of low power consumption, reliability, scalability, and security as well as high real-time data transfer [22]. It operates on 2.4 GHz frequency band, supports high data rates up to 250 kpbs [22]. The specification of an upper data link layer, network layer, UDP and TCP and application layer are defined. In addition, ISA100.11a is IP enabled and supports IPv6. Unlike WirelessHART, not all devices in ISA100.11a network must have routing capability. Without it, devices must be within one hop of a routing-capable device or the gateway. In larger networks, this disadvantage makes ISA100.11a unsuitable for MNM. The best solution for MNM is ZigBee standard since it supports 6 LoWPAN and RPL protocols to connect WSN nodes to the Internet. With appropriate routing protocols are also possible to establish the system of WSN gateways needed to provide interlayer communication. The role of WSN gateways will be further discussed in Section 3.5.
## 4 Experiment Results and Analysis
### Control Performance Analysis of the Pure ASP Algorithm  
#### 4.1.1 Noise Reduction Performance for Noise Canceling  
For comparison of the noise reduction performance of the three orders (C2, C4, and C8) for canceling order noise, the noise reduction \(L_{NR}(f)\) between the measured error signal before and after controls can be defined as  
\[L_{NR}(f)=L_{E}(f)-L_{before}(f), \tag{10}\]  
Figure 6: Impulse response of the nominal secondary path \(S_{0}(z)\).  
where \(f\) means frequency in r/min, \(L_{E}\) is the A-weighted SPL of the measured error signal, and \(L_{before}\) is that before control. This quantity indicates how much the SPL of the error signal is suppressed from that of before control, and it can be expressed in average over the engine speed range of 1000-5500 r/min for each engine order as \(L_{NR,\text{Avg}}\). \(L_{NR,\text{Avg}}\) of the C2, C4, and C8 before and after controls are summarized in Table 2.  
Figure 7 shows the comparisons of the SPLs of the C2, C4, and C8 before control (dotted lines) and after the pure ASP control (thin solid lines). Figure 7a,b displays the SPLs \(L_{E}(f)\) of the C2 before and after controls and the noise reduction \(L_{NR}(f)\) defined in Equation (10), respectively. In addition, the leakage term used in the real-time control experiment for the C2 order was attached to the upper side of each figure. Figure 7c,d displays those of the C4 order, and Figure 7e,f plots those of the C8 order.  
As can be seen from Figure 7, when the ASP control was applied, \(L_{E}(f)\) of the C2, C4, and C8 orders were attenuated dramatically over the almost entire engine speed range compared with those before control. Especially, in each order, \(L_{NR}(f)\) at the largest booming noise was achieved by about \(-24\), \(-20\), and \(-17\) dBA at about 4600, 4300, and 4200 r/min, respectively, and \(L_{NR,\text{Avg}}\) after control was obtained as \(-8.0\), \(-6.8\), and \(-6.6\) dBA, respectively, as displayed in Table 2.  
It is noteworthy that there were few changes in the SPLs before and after controls at some engine speed where the leakage value was 0.98. Nevertheless, due to the leakage term scheduled with frequency, the pure ASP algorithm maintained its stability robust over the entire engine speed range in the real-time control experiments.
## 2 Methodology
### Establishment of the Landscape Visual Evaluation Method
If the CR < 1, the consistency test is considered acceptable; otherwise, the matrix elements must be changed and rescaled according to Table 1 until the CR satisfies the consistency condition. The calculation of the CR is shown in Equation (15), where the RI (random consistency index) needs to be looked up in Table 2.  
\[CR=\left(\frac{\lambda-\text{n}}{n-1}\right)\times\left(\frac{1}{RI}\right) \tag{15}\]  
where n represents the order of the matrix and \(\lambda\) represents the maximum eigenvalue of a matrix of order n.  
By selecting, modeling and calculating the weights of the landscape visual evaluation indicators, the weights of each indicator were finally obtained as shown in Tables 3-6. \begin{table}
\begin{tabular}{c c} \hline \hline
**Scale** & **Meaning** \\ \hline
1 & Element \(i\) is as important as element \(j\) \\
3 & Element \(i\) is slightly more important than element \(j\) \\
5 & Element \(i\) is stronger and more important than element \(j\) \\
7 & Element \(i\) is more important than element \(j\) \\
9 & Element \(i\) is more important than element \(j\) \\
2,4,6,8 & Element \(i\) and element \(j\) are intermediate in importance \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Important levels from 1 to 9. \begin{table}
\begin{tabular}{c c} \hline \hline
**n** & **RI** \\ \hline
1 & 0 \\
2 & 0 \\
3 & 0.58 \\
4 & 0.90 \\
5 & 1.12 \\
6 & 1.24 \\
7 & 1.32 \\
8 & 1.41 \\
9 & 1.45 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Average random consistency indicator RI values. (3) Calculation of the landscape visual assessment total scores  
After calculating the weighted sum of the indicator values and the weights of each target point, the landscape visual evaluation score (LVES) of each target point is obtained (as shown in Equation (16)). We then obtain the total score for the landscape visual evaluation by summing up the scores of all the target points corresponding to the observation point (as shown in Equation (17)). \[LVES_{k}=\sum_{k=1}^{k}IV_{k}\times W_{k} \tag{16}\]  
\[LVES=\sum_{n=1}^{n}LVES_{k} \tag{17}\]  
where \(LVES\) represents the total score for the landscape visual evaluation of the observer point, \(LVES_{k}\) represents the landscape visual evaluation score for the target point, \(k\) represents the number of indicators, \(IV_{k}\) represents the value of each indicator, \(W_{k}\) represents the weight value corresponding to each indicator and \(n\) represents the number of target points corresponding to the observer point.
# Encrypted Client Hello Is Coming: A View from Passive Measurements
## 2 Background and Related Work
[15] in 2022. The authors used a web crawler to verify ESNI and ECH support in the top 1M domains in terms of popularity. They found that only a small portion, less than 19%, supported the former ESNI extension, and practically no domain supports ECH. In 2023, [PERSON] et al. [16] studied ECH adoption by measuring the availability of ECH public keys in HTTPS DNS records. Across more than 400 M domains, they found 10.5 M HTTPS records. Cloudflare hosted and served most of those domains, and most records contained only Application-Layer Protocol Negotiation (ALPN) and IP address hints while missing the ECH public key. More recently, in 2024, [PERSON] et al. [17] performed a similar study, offering a longitudinal perspective on the server-side deployment of DNS HTTPS for the Tranco top million domains. They observed a growing trend in DNS HTTPS adoption, and, despite its recent standardization, over 20% of probed domains had DNS HTTPS records. All the aforementioned works used active measurements in the form of web crawlers and DNS resolutions; thus, they targeted server-side deployment of ECH and HTTPS DNS. In contrast, in this paper, we use passive measurements, monitoring the operational traffic of a population of real users. Thus, we offer a different and complementary perspective, measuring client-side adoption and watching ECH and HTTPS DNS in operation.
## 2 Overview of Supplementary Damping Systems
### Principles of Energy Dissipation Mechanisms
#### 2.2.1 Viscous Damping  
Viscous damping is based on the principle of fluid dynamics, where energy is dissipated through the movement of a piston in a viscous fluid. The damping force, F, is proportional to the velocity, v, of the piston:  
\[\text{F}=\text{C}\cdot\text{v}^{\text{a}} \tag{1}\]  
where C is the damping coefficient and a is the velocity exponent (typically between 0.3 and 1.0).  
Key characteristics of viscous damping include:  
Velocity-dependent behavior.  
Out-of-phase response with displacement.  
Temperature sensitivity.  
Frequency independence (for linear viscous dampers).  
\begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Damper Type** & \begin{tabular}{c} **Energy** \\ **Dissipation** \\ **Mechanism** \\ \end{tabular} & **Key Characteristics** & \
\begin{tabular}{c} **Primary** \\ **Applications** \\ \end{tabular} & **Advantages** & **Limitations** &
\begin{tabular}{c} **Detailed** \\ **Discussion** \\ \end{tabular} \\ \hline Friction & \multirow{4}{*}{Surface friction} & \multirow{4}{*}{Surface friction} & \multirow{4}{*}{Surface friction} & \multirow{4}{*}{\(\bullet\)} & Displacement & \multirow{4}{*}{\(\bullet\)} & Multi-story buildings & \multirow{4}{*}{\(\bullet\)} & High energy dissipation & \multirow{4}{*}{\(\bullet\)} & Wear and tear & \\  & & & dissipation & & Temperature & & & \\  & & dissipation & & & independent & & & \\  & & & Consistent & structures & & Low maintenance & & & \\  & & & performance & & & & & \\  & & & Stable hysteretic & & & & & & \\  & & behavior & & & Building & & & & \\  & & Load path & & structures & & & & \\  & & redundancy & & Bridge & & & & \\  & & Displacement & & structures & & & & \\  & & dependent & & & & & & \\  & & & & & & & \\  & & & & & & & & \\  & & & & & & & & \\  & & & & & & & & \\  & & Frequency & & & & & & \\  & & tuned & & & & & & \\  & & & & & & & \\  & & & & & & &
## 2 Materials and Methods
### Recycled Concrete Aggregates (HR and CR)
#### 2.1.1 Recycled Aggregate Properties Testing  
The aggregate tests that were conducted were the sand equivalent test according to EN 933-8 and methylene blue test according to EN 933-9, in order to determine the quantity and quality of their fines. Grain size distribution was measured according to EN 933-2, in order to simulate similar aggregate gradation to that of the natural aggregates. Density (bulk, dry, saturated surface dry) and water absorption for the saturated-surface dry (SSD) condition were determined in order to perform the concrete mix design. Since water absorption for the recycled aggregates is usually higher than that of natural aggregates, the recycled aggregates were used in the SSD condition in order to have the same effective w/c ration in all mixtures. X-ray diffraction analysis (XRD) was used for the determination of the mineralogical composition, with a PW 1840 Phillips diffractometer (Philips, Amsterdam, Netherlands) and Ionic Chromatography for the determination of the water-soluble sulfate salts content (SO\({}_{3}\)wt %), with Dionex CS-1100, Thermoscientific Instruments (ThermoFisher Scientific, Waltham, USA). Regarding the assessment of the durability of the recycled aggregates, two tests were carried out: resistance to fragmentation (Los Angeles test) according to EN 1097-2 and resistance to freezing and thawing according to EN 1367-1.
## 3 Performance Analysis and Simulations
### Irradiance Uniformity vs. Optical Loss
#### 3.1.3 Acceptance Angle  
In the CPV field, an acceptance angle is the incidence angle at which the concentrator collects 90% of the on-axis power. The acceptance angle has a tradeoff with the concentration. Increasing the acceptance angle reduces the concentration permanently [34]. This tradeoff is described through the concentration-acceptance angle product (CAP), being an appropriate merit function for a concentrator:  
\[CAP=\sqrt{C_{\mathrm{g}}}\mathrm{sin}\ \alpha, \tag{7}\]  
where \(\alpha\) is the acceptance angle, and \(C_{\mathrm{g}}\) is the geometric concentration, defined as the ratio of the concentrator aperture area to solar cell area [19].  
Figure 8: (**a**) comparison of incident power received at the cells of the conventional and proposed CPV units; and (**b**) optical loss of the proposed CPV unit compared to the conventional CPV unit.  
Figure 9a,b demonstrate the ray-tracing results of the conventional and proposed CPV units, respectively, when the incidence angle is \(1.2^{\circ}\).  
The ray-tracing results showed that the proposed CPV unit with using a simple plano-concave lens as the SOE reduced a few incidence angle of sunnrays compared to the conventional CPV unit. This resulted in a small reduction in the acceptance angle of the proposed CPV unit. To a certain degree, however, using accurate two-axis sun tracking system in the proposed CPV system can overcome the problem.  
Figure 10 shows the angular transmission curve for both CPV units. The simulation results show that the proposed CPV unit has a 90% acceptance angle of \(\pm 1.05^{\circ}\), which is a little less than the conventional CPV unit, whose acceptance angle is about \(\pm 1.16^{\circ}\).
## 6 Use Case: Cyber and Physical Attacks against a Water Critical Infrastructure
### Anomalous Network Traffic  
The attacker performs multiple actions that are considered anomalous and that could be detected by a machine learning algorithm. The attacker uses an IP address (i.e., 192.168.66.5) to perform all the commands that would allow him/her to discover and exploit vulnerabilities in the target infrastructure. However, the Network Traffic Sensor and Analyzer has already built a model of the regular behavior of the water CI traffic and is able to detect abnormal actions (e.g., abnormal connections to IP addresses, abnormal protocols used, abnormal ports opened, etc.). For this purpose, we need to obtain a NetFlow of the network traffic.  
The NetFlow information considers timestamp (date at which the flow started) a duration of the flow, the protocol involved (e.g., UDP, TCP), IP addresses and ports (source and destination), as well as the number of packets, size (in bytes) and the number of flows. The NTSA analyzes all this information and focuses on the IP addresses to determine which of them are considered normal (they belong to the regular communications performed in the network), or abnormal (new IP addresses detected and considered to be malicious). The main parameters evaluated are IP location (internal or external to the network); IP distance (distance between the modeled IP and the new ones); and IP knowledge (known or unknown IPs) as described in [1].  
The NTSA needs to check in real time the network to compare with the created model if there are abnormal situations. Examples of the NTSA messages received by the XL-SIEM are given as follows:  
* Dec 18 13:02:41 cyberagent logger Dec 18 13:02:40 172.16.4.199 [L-ADS] ERROR: [src_ip=192.168.66.5, src_port=0, dst_ip=192.168.66.6, dst_port=0, proto=58, desc= \"Abnormal observation\"]#015
* Dec 18 13:02:41 cyberagent logger Dec 18 13:02:40 172.16.4.199 [L-ADS] WARNING: [src_ip=172.16.23.77, src_port=0, dst_ip=192.168.66.6, dst_port=0, proto=58, desc= \"172.16.23.77 not modeled\"]#015  
Examples of the security events coming from the NTSA and displayed by CLAP are given bellow:  
* L-ADS ERROR: Abnormal observation; 2019-12-18 14:02:41; xlsiem-server; 192.168.66.5; 192.168.66.6; 4
* L-ADS WARNING: IP not modeled; 2019-12-18 14:02:41; xlsiem-server; 172.16.23.77; 192.168.66.6; 3  
As can be seen in the previous examples, we received two distinct events from the NTSA. One is an error and refers to an abnormal observation in a specific IP address (which will be considered an abnormal event), and the other is a warning indicating that the NTSA was unable to model the IP, and therefore no analysis was performed. Events received from NTSA are assigned a severity of three, meaning that the risk level is low and should be further analyzed.
# Experimental Simulation of Thunderstorm Profiles in an Atmospheric Boundary Layer Wind Tunnel
###### Abstract  
Thunderstorms have different features in comparison with synoptic events, including a typical nose-shaped mean wind speed profile and non-stationary characteristics in time intervals from 10 min to 1 h. The simulation of thunderstorms in traditional wind tunnels requires suitable devices in order to replicate their peculiar characteristics. Disregarding the non-stationary characteristics of thunderstorm outflows, this paper aims to study the possibility of adopting a passive device such as a specially designed grid in order to reproduce the nose-shaped mean wind speed profile. A widely adopted model of the mean wind velocity profile from the literature is employed as a target profile for the verification of the experimental findings. The results obtained show a good agreement between the measured and target mean wind speed profiles and an acceptable turbulence intensity level compared with full-scale and experimental measurements. The proposed device offers a practical and cost-effective solution to simulate the main characteristics of a thunderstorm event in a traditional atmospheric boundary layer wind tunnel, which could be adopted to assess the significance of thunderstorm loading on civil engineering structures and define the requirement for ad hoc specialist studies.  
mean wind speed profile; thunderstorm downbursts; turbulence intensity profile; wind tunnel tests +
Footnote †: journal: Applied Sciences
# Pico-Sat to Ground Control: Optimizing Download Link via Laser Communication
### Related Work
More specifically, their solution uses high-altitude platforms as mobile relay stations that deliver the data from the satellite to the vehicles (end-users). The communication between the components in this network uses FSO communication as an encrypted channel and RF communication as a public channel. The secure link is based on QKD encryption. Recently, the use of MEMS gimbals was presented in the concept of full-duplex FSO communication [13, 14], allowing a significant miniaturization of FSO robotic (dynamic) sensors. The space laser-communication research field is not limited to the Earth-space link. New space developments can also support satellite networks which are based on laser communication. NASA has already created the CubeSat Laser Infrared Crosslink (CLICK) [15] mission to demonstrate a full-duplex optical communication crosslink between two 3 U small spacecrafts in LEO. The goal of this mission is to create a satellite constellation or swarm that carries one or more moderate- to high-resolution imaging or scientific sensors and communicates at high speed. The concept of a nano-satellite with emitting lights that should be visible by the naked eye was first implemented on the FITSat-1 nano-satellite [16]. Figure 2 presents the first LED flashing of FITSat-1 (2012). Finally, NASA's Terabyte InfraRed Delivery (TBIRD) program is designed to allow 200 Gbps laser communications system for LEO direct-to-Earth missions; recent preflight tests [17] show promising results regarding the ability of optical ground stations to track and establish laser links with FSO nano-satellites. This work describes a framework that combines FSO and RF Earth-celestial communication. It relies on new studies on space FSO that have already demonstrated the feasibility of creating an optical link in space. [PERSON] et al. [18] presented a link-budget analysis of a hybrid FSO-RF transmission system for communications links of up to 12 km in clear sky conditions. [PERSON] et al. [19] proposed an FSO system simulated at 10 Gbps bit rate and 2 km path link with different modulation types. An analysis for FSO link 1550 nm waves in 50 km was performed by [PERSON] and [PERSON] [20]. They claim that most commercial off-the-shelf (COTS) components for fiber communications can also be used for FSO communication, especially at the optical C band, in which there are fewer absorption peaks. This is because the standard communication wavelengths (1550 nm) do not coincide with spectrum lines of strong absorption.