esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Artificial Intelligence as Enabler for Adoption of Nuclear Maritime Ships
### Cybersecurity  
Modern ships are fully equipped with digital systems to enhance operational efficiency. However, as in other domains, the digitization of ships also introduces vulnerabilities to cyberattacks [85]. While satellite connectivity provides essential access to the internet and facilitates communication, it also serves as a potential entry point for cyber threats [86].  
Furthermore, the use of wireless technologies for data exchange and monitoring on board introduces additional vulnerabilities, as they may attract cybercriminals seeking to compromise nuclear control and monitoring systems for nefarious purposes [87]. Since wireless and digital connections are essential for reducing operational costs and cannot be replaced with analog alternatives, implementing robust cybersecurity measures is imperative [88].  
Figure 4: Security architecture for nuclear material accountability, where AI analyzes data to make inferences concerning onboard activities associated with nuclear materials.  
A wide range of cybersecurity solutions has been proposed and tested across various domains. As a well-researched topic, AI-driven cybersecurity solutions can be adapted and tailored to meet the specific needs of nuclear ships. Of particular interest are AI technologies capable of detecting cyberattacks in real-time and performing rapid cyber-forensic analysis [89]. Additionally, intelligent decision-making systems can provide mitigation plans to recover from attacks when detected [90], while LLMs can assist human operators in identifying and following the correct set of security protocols [91].  
At this point, it is important to note that before deploying any cybersecurity measures, the ship's critical digital assets (CDAs) must first be identified [92]. Since there is no prior experience with fully digital nuclear maritime operations, AI foundation models can be trained on data from related fields--such as civilian nuclear power plants and nuclear submarines--to generate a comprehensive list of CDAs tailored to the specific nuclear ship in question, as shown in Figure 5.
## 3 Results
### Rhyzopertha domitica  
Mortality of _R. domitica_ adults observed to be affected by the insecticides applied in steel surfaces after 1 d (\(\chi^{2}\) = 31.1, \(p\) < 0.01, df = 3), after 3 d (\(\chi^{2}\) = 32.4, \(p\) < 0.01, df = 3) and after 7 d (\(\chi^{2}\) = 34.1, \(p\) < 0.01, df = 3) to the lower dose, and after 1 d (\(\chi^{2}\) = 29.0, \(p\) < 0.01, df = 3), after 3 d (\(\chi^{2}\) = 34.3, \(p\) < 0.01, df = 3) and after 7 d (\(\chi^{2}\) = 34.1, \(p\) < 0.01, df = 3) in the higher dose (Figure 3). Zeolite was the most effective against _R. domitica_, causing over 60% mean mortality after only 1 d of exposure to both doses tested, followed by DE6 and DE5 respectively. Adult mortality was 100% or close after 3 d of exposure, regardless of the insecticide and dose. Still, significantly lower was the control's mortality compared to the treatments with the insecticides, until the 14 th d of exposure (Figure 3).  
In concrete surfaces, differences were observed among the treatments after 1 d (\(\chi^{2}\) = 30.1, \(p\) < 0.01, df = 3), 3 d (\(\chi^{2}\) = 34.3, \(p\) < 0.01, df = 3) or 7 d (\(\chi^{2}\) = 34.0, \(p\) < 0.01, df = 3) of exposure to the lower dose, and after 1 d (\(\chi^{2}\) = 30.9, \(p\) < 0.01, df = 3), 3 d (\(\chi^{2}\) = 34.3, \(p\) < 0.01, df = 3) and 7 d (\(\chi^{2}\) = 34.0, \(p\) < 0.01, df = 3) and 7 d (\(\chi^{2}\) = 34.0, \(p\) < 0.01, df = 3) to the higher dose (Figure 4). Zeolite and DE6 were equally more effective than DE5 or control in both doses, with over 60% mortality after 1 d of exposure. Nevertheless, complete control was achieved after 3 d of exposure to all insecticides and doses tested, while adults of the control treatments were dead after 14 d (Figure 4).  
Figure 2: Mortality (%) of _S. oryzae_ adults after exposure for 1, 3, 7 and 14 d at three different doses [0 (control), 0.5 and 1 g/m\({}^{2}\)] of DEs and zeolite applied on concrete surfaces (boxplots followed by the same letter are not significantly different, according to the Dunn test at \(p\) < 0.05, where no letters exist, no significant differences were noted).
## 1 Introduction  
Many kinds of sound signals are applied to convey information in Japanese public spaces. These signals can be divided into three groups. First, alarm signals are used to provide information about potentially life-threatening events. Second, attention signals are used to provide information about basic infrastructure, such as the locations of stairs, toilets, and ticket gates. Third, announcements are used to convey information via speech.  
The guidelines for improving the facilitation of transportation for passenger facilities of public transportation in Japan [1] recommend the use of simulated birdsong for attention signals that inform visually impaired people about the location of stairs in train stations. It is required to adjust the sound pressure levels (SPLs) of the signals to avoid excessive or insufficient volume, and to ensure that they cause no discomfort to users, staff, or surrounding residents. However, a previous study found that more than 40% of visually impaired people reported that such signals were hard to detect [2]. Thus, there is a need for the development of attention signals that are not unpleasant and can be presented at high SPLs.  
Introducing birdsong into public spaces has been found to increase the subjective pleasantness of the soundscapes [3]. Among natural sounds, birdsong is reported to be judged as the most effective and beneficial type of sound for improving sound environments [4; 5; 6]. Similar to birdsong, insect song has been shown to have a positive effect on soundscapes [5; 7]. Thus, birdsong and insect song are less likely to negatively affect sound environments in public spaces, even when presented at high SPLs.  
Previous soundscape studies of birdsong and insect song have reported positive effects. However, users' preferences for various types of birdsong and insect song are currently unclear. Specific types of birdsong or insect song may have a more positive impact on sound environments in public spaces. The aim of the current study was to clarify which types of birdsong and/or insect song are preferred, and to determine the dominant physical characteristics related to these preferences.
# SDN-Based Routing for Backhauling in Ultra-Dense Networks
## 3 Software-Defined Backhaul Network  
An SDN-based backhaul network is composed by a set of forwarding elements as a traditional network. However, while in traditional networks the control is distributed in every node (i.e.,routing protocols are executed in every node), in SDNs devices are simply forward nodes without any control function.  
The main pillar of SDN is decoupling control and data planes: the first one is represented by the SDN controller that aggregates and performs control decisions, while the second is represented by forwarding nodes and links connecting these nodes, and simply becomes packet forwarding. In particular, the main elements of an SDN network are:  
* _forwarding devices_ (FD)--physical devices that accomplish instructions that are provided by the SDN controller throughout the southbound interface, which is installed by the SDN controller on devices depending on the used protocol;
* _southbound interface_--the interface that defines the communication protocol and the instructions set that are given by the SDN controller to FDs;
* _SDN controller_--the central controller that represents the network intelligence that instructs the FDs;
* _northbound interface_--the interface of the SDN controller toward the applications. Usually, a northbound interface abstracts the low-level instructions set used by southbound interface to program FDs;
* _application plane_--the set of applications that define the policies that are then translated in instructions to program the forwarding elements. Examples of applications are routing, monitoring, and load balancing.  
In an SDN the control logic is moved on an external entity and is programmable via software. The SDN controller supervises the behavior of the forwarding elements through an open programming interface such as OpenFlow. The controller can translate the application requirements down to the data plane, and to provide an abstracted view of the physical network to applications. More in detail, the SDN controller defines forwarding rules that are pushed down to the FDs, which simply match the rules with the incoming data flows. Simplifying the functionality of FDs, these can be implemented on general-purpose hardware and controlled with standard protocols. This leads to a significant flexibility increase respect to traditional networks where each router must perform control functions and implements proprietary interfaces that cannot be reconfigured via software. Moreover, if significant changes frequently occur (like in case of UDNs), traditional networks present a significant signaling increase and longer convergence time of routing algorithms. Differently, centralized control operations require less communications (i.e., signaling) and shorter delays. SDN controller must have an updated global view of the network connectivity and throughput. When a change occurs in the network, the SDN knowledge is updated.
## 1 Introduction
In reference [16], a MIMO antenna consisting of four circular monopole patches and electromagnetic band-gap (EBG) elements was suggested, where four semi-circular ring-shaped slots were engraved on the radiating patches to obtain a notched-band. A four-element UWB MIMO antenna design with a mushroom-like EBG structure to a notch 5.5 GHz band was suggested [17]. In [18], a quad-port UWB MIMO structure with two notched frequency bands was suggested, where the dimensions of the antenna were optimized by using an iterative design method. In this communication, a planar, compact, MIMO antenna comprising four identical octagonal-shaped resonating elements is proposed. The unit element contains a microstrip line of impedance 50 \(\Omega\), octagonal-shaped monopole resonator, and a rectangular-shaped ground surface. A hexagonal-shaped complementary split-ring resonator (HCSRR) was embedded in the monopole antenna patch to notch the interfering Wi-MAX and WLAN frequencies. The MIMO/diversity antenna elements are arranged in orthogonal orientation, and spacing was introduced between them to achieve higher isolation. Metallic strips are also inserted between the monopole elements in order to connect their ground surfaces to obtain common voltage intensity in the MIMO structure. The metallic strips also increase the isolation among four resonators of the MIMO/diversity antenna.
## 4 Discussion
In some regions, the data may not be available daily due to cloud cover or other atmospheric conditions. Regarding flood risk, despite the quality of data derived from IoT sensors, it can be influenced by the non-uniform distribution of the monitoring stations, which can lead to potential distortions in the results. Therefore, the overall quality of the digital twin may be limited by the availability and quality of geospatial data in different cities. The proposal aims, first and foremost, to provide concrete and quantifiable answers to these two phenomena, which particularly affect the city of Reggio Calabria, while also leaving room for the implementation of new monitoring and analysis strategies. The digital twin developed is designed to be generalizable and scalable, allowing adaptation to other cities or regions with different geomorphological and infrastructural characteristics. Scalability is ensured using standardized geospatial data from hydraulic and light pollution models based on adaptable parameters. The model's modular architecture allows for the integration of new data sources. In addition, the calibration methodology can be replicated using local historical data, improving the accuracy of simulations in each application area. The integration of AI and ML techniques, when used independently, represents a powerful resource to enhance predictive analytics and urban resource management. Regarding hydrogeological risk, deep learning can analyze historical rainfall data, hydrometric levels, and satellite imagery to more accurately predict flood events and identify vulnerable areas in real time. Regarding light pollution, clustering algorithms and time series analysis can identify patterns of inefficient energy consumption and suggest strategies for optimizing public lighting. In addition, the use of AI for IoT data analysis enables the processing of large volumes of information in real time, facilitating the creation of dynamic and adaptive scenarios for urban planning. The integration of these advanced tools not only improves the accuracy of simulations but also enables early warning systems and automated solutions for urban resilience. Moreover, using IoT sensors, satellite imagery, and data from weather stations, the model can be updated in real time to monitor changes in light pollution levels, hydrological conditions, and other critical environmental parameters. This approach allows for early detection of changes in the terrain, prediction of future trends, and support for decisions based on up-to-date data. In the case of hydrogeological risk, continuous monitoring of water levels in basins and rainfall allows early warning systems to be activated, improving emergency management. In the case of light pollution, dynamic monitoring makes it possible to optimize public lighting strategies, reducing energy consumption and environmental impact. In addition, thanks to artificial intelligence and machine learning algorithms, the digital twin can adapt to urban changes, suggesting infrastructure changes and mitigation strategies based on simulated scenarios.
## 3 Calibration of System Parameters
### Orientations of the Two Screens  
The luminance nonlinearity caused by the gamma effect of the digital screen and camera is the major error source of digital phase shift technology [43]. As a result, gamma correction is necessary to reduce the influence for the following calibration process. This paper adopted a direct, simple, and effective method by encoding initial fringe pattern based on [PERSON]'s paper [44]. Then, horizontal and vertical encoded sinusoidal fringe patterns with the optimum fringe numbers were subsequently generated and displayed on LCD\({}_{1}\)\({}^{\prime}\) and LCD\({}_{2}\) to determine the orientations of the two LCD screens in the same camera coordinate system. However, the fringe patterns were reflected by the reference mirror and captured by the CCD camera from another position for post-processing. Because phase data were calculated from the captured sinusoidal fringe patterns, they were insensitive to the imaging lens being out of focus. The phase of each pixel on the two LCD screens could be known using certain fringe numbers.  
Absolute phase data were calculated using the optimum three-fringe number selection method and a four-step phase shifting algorithm. However, the phase data in the location of the circles could not be obtained correctly due to the low fringe modulation, as illustrated in Figure 3a for the horizontal fringe pattern. Because all phase data were located on the plane mirror, a plane could be fitted by using the obtained correct phase data without circles. This process can eliminate the influence of the inaccurate phase data in the location of the circles, as shown in Figure 3b.  
Figure 2: Image of hollow ring marker matrix captured by the camera: (**a**) texture image and (**b**) red dots representing the center of each hollow ring marker.  
A two-dimensional feature point matrix can be designed for the LCD screen to match the calibration requirements, as illustrated in Figure 4. The world coordinate and corresponding phase data of each feature point can be determined by following equations:  
\[\frac{x_{w}}{\phi_{x}}=\frac{n_{x}\times p}{2\pi}, \tag{7}\]  
\[\frac{y_{w}}{\phi_{y}}=\frac{n_{y}\times p}{2\pi}, \tag{8}\]  
where \(p\) is the size of LCD screen pixel pitch, \(n_{x}\) is the number of LCD screen pixels per horizontal fringe, and \(n_{y}\) is the number of LCD screen pixels per vertical fringe. According to Equations (7) and (8), one camera pixel can uniquely locate its corresponding physical position (\(x_{w}\), \(y_{w}\)) in the world coordinate system based on its phase value (\(\varphi_{x}\), \(\varphi_{y}\)).  
As a result, the position of each feature point in the unwrapped phase map was determined using a phase matching algorithm. The absolute phase of every pixel was invari  
Figure 4: Feature point matching using absolute phase data.  
Figure 3: Absolute phase on the mirror surface for a horizontal fringe pattern: (**a**) absolute map with inaccurate phase data for the hollow ring markers and (**b**) absolute map processed with a 3D surface fitting algorithm.
# Secure Authentication and Credential Establishment in Narrowband IoT and 5G
## 6 Experimental Results  
### Code Footprint  
Code footprint was also taken into consideration during the developing of the testbed. For this reason, the development employed libraries targeted at constrained devices in order to maintain a low programmable memory size. For peripheral communications with the Quectel BG96 NB-IoT modem, a modified version of the _Tuino Zero 96_ library ([[https://github.com/gimasi/TUINO_ZERO_96](https://github.com/gimasi/TUINO_ZERO_96)]([https://github.com/gimasi/TUINO_ZERO_96](https://github.com/gimasi/TUINO_ZERO_96))) was employed. Mainly, the modifications encompassed an implementation in transparent mode for the IP/UDP sockets. This library was employed in both PANA and LO-CoAP-EAP experiments. In both cases, it had a footprint of 2571 bytes of programmable memory. The libraries employed for managing the EAP authentication process were based on _PANATIKI_, which is a PANA implementation for the Contiki OS ([[https://github.com/contiki-os/contiki](https://github.com/contiki-os/contiki)]([https://github.com/contiki-os/contiki](https://github.com/contiki-os/contiki))). In the case of LO-CoAP-EAP, the EAP libraries were adapted to work in the Arduino framework and encode/decode CoAP packets. Likewise, the PANA implementation of the testbed required some adaptation of the _PANATIKI_ libraries in order to work with Arduino. After the adaptation process, the compiled code size was 8916 bytes in the case of LO-CoAP-EAP and 7586 bytes for PANA. In either case, the total sum of the Quectel BG96 libraries and EAP authentication libraries stayed below 11.5 KiB. Thus, this implementation was considered reasonable for a wide variety of constrained IoT devices that can manage our proposal efficiently. For instance, a similar device to the one employed in this scenario is the _Arduino Nano_, which also includes the SAMD21 MCU at 48 MHz and 32 KB of SRAM. As a consequence, the minimum hardware required to achieve authentication would be similar to that of a _Class 1_ constrained device as defined in [9]--that includes any NB-IoT compatible radio modem with UDP support, e.g., _Quectel LTE BC95_.
## 5 Emerging Trends in FSO Communication
### Orbital Angular Momentum-Aided FSO Systems  
Several multiplexing methods, such as WDM, space division multiplexing (SDM), and polarization division multiplexing (PDM), have been employed to enhance the transmission capacity of FSO communication systems. However, the numerous limitations and the complex architecture of FSO Rxs make it challenging to significantly boost the transmission capacity further. Recently, a new multiplexing technique known as OAM has gained prominence among researchers for its potential to further increase the capacity of FSO systems [457]. So, in future ultra-fast optical communication, besides the widely applied characteristics of light, including amplitude, phase, polarization, and wavelength, the OAM will offer a new degree of freedom of light beams. In principle, light beams carrying different OAM states are mutually orthogonal, and the number of OAM eigenstates is infinite. Therefore, the application of OAM provides alternative technologies to meet the ever-increasing bandwidth demands in wireless communication systems [2; 458].  
Moreover, to enhance the data transmission capacity of FSO communication, techniques utilizing OAM--a fundamental property of Laguerre-Gaussian (LG) beams--have been proposed and garnered significant attention [459]. Leveraging the theoretically unlimited range of available OAM states [460], OAM division multiplexing [461; 462] and OAM-shift keying (OAM-SK) [463; 464; 50] can significantly improve the capacity of FSO communication systems. Specifically, in OAM division multiplexing, LG beams carrying various OAM states act as channels to multiplex information streams [458]. Traditionally, these beams are multiplexed at the Tx and then transmitted through the atmosphere to the Rx, where they are demultiplexed due to their orthogonal properties [465]. Meanwhile, in OAM-SK, information is modulated into LG beams with different OAM modes, representing a new modulation format. The OAM-SK-FSO communication system offers distinct advantages, including reduced equipment costs, increased transmission distances, enhanced photon efficiency, and improved information security. This makes it particularly suitable for cost-effective emergency communication and medium-distance FSO applications, such as high-dimensional QKD and deep-space or near-Earth communications. Additionally, advancements in SLMs can further enhance the capacity of OAM-SK communication systems.