esa-sceva/satcom-chunk-collection huggingface dataset:
# DeAPIR: Efficient and Enhanced Dental Arch-Guided Panoramic Image Reconstruction from CBCT Data
###### Abstract
In comparison to conventional software approaches that rely on dental CBCT images instead of projection data, the proposed method offers advantages, as it is not contingent on the quality of the CBCT image; rather, it directly reconstructs the panoramic image from the extracted projection data. The main contribution of this work is listed below:  
* Dental Arch Detection: The proposed method detects a highly accurate dental arch from the existing dental teen slices only. Teeth localization is achieved by thresholding the moving average intensity values extracted from the front view MIP image. Further enhancement of the dental arch is accomplished through a series of morphological operations, including dilation, filtering, and skeleton detection methods. * Dental Arch Approximation and Extension: The proposed framework employs the quadratic kernel-based curve fitting to generate a mathematical expression that best fits the dental arch. The extension of the dental arch up to the TMJ locations is then obtained through that quadratic expression. * Localized Maximum Intensity Project Stitching: Trajectory-based cubic segments are extracted and rotated to an angle perpendicular to the dental arch at that specific coordinate point. The localized MIP obtained from each rotated cubic segment is then cropped and stitched together to obtain the panoramic view of the given CBCT data. * Contrast Enhancement Operation: The low-contrast raw panoramic image obtained through the proposed framework shows fewer details of the gums, teeth, and TMJ section. It is further enhanced by the post-processing contrast normalization procedure to display a more detailed panoramic image at the output. The rest of the paper is structured as follows: Section 2 outlines the methodology of the proposed model, offering detailed explanations of each step supported by mathematical models. In Section 3, we analyze the experimental findings and compare them to state-of-the-art models. Lastly, Section 4 wraps up the paper, delving into potential avenues for future research.
# Performance Analysis of Two-Hop mmWave Relay Nodes over the 5G NR Uplink Signal
## 4 Simulation Results and Discussion
### Comparative Discussion  
In this subsection, to address the complexity of the proposed millimeter band NR-relay nodes, hardware implementation and the arithmetic operations they perform are considered. Firstly, taking into account the development hardware approach, all the proposed relay node technologies are designed considering the same elements, which were explained in the previous sections. However, Table 4 summarizes the required arithmetic operations of the proposed relaying technologies, considering the step of capture, processing, and forwarding of the received signal to the gNodeB.  
It should be verified that the A&F relay node presents less computational complexity, where \(\rm N_{T}^{R}N_{R}^{R}T\) and \(\rm N_{T}^{R}(N_{R}^{R}-1)\), multiplications and summations, respectively, are required. In addition, both D&F with PCE and LS relay nodes perform stages of decoding and encoding processes, which increase the complexity. From Table 4, it should highlighted that \(\rm N_{T}^{R}\times N_{R}^{R}\) is the combiner antennas in the NR-relay nodes and \(\lambda\times\alpha=\rm P\) explains the total number of the pilot symbols. Additionally, \(\mu\) represents the total number of the data symbols, which are employed to implement the interpolate method. Considering this, the D&F with PCE has knowledge of the radio channel, the complexity of the protocol decreases, substantially, in comparison with D&F with LS, due to the channel estimation and interpolation algorithms are not performed in the decoding step. Accordingly, \(\rm N_{T}^{S}N_{R}^{R}[\frac{\alpha(\alpha+1)}{2}(\lambda+\alpha-1)+94\mu]\) fewer operations are required achieved with this strategy.  
The KPIs of the co-operative system have been studied in previous works, which consider a similar architecture, using the network model, frequencies bands, and hardware approach. In this context, a brief comparison with prior works [31; 32; 33] is performed. The first conclusion of these works is that the D&F relay node is able to achieve higher performance compared to the A&F. Nevertheless, the main limitation found in these works is the implemented signal model, which does not fulfill the 5G 3 GPP requirements--for example, the physical uplink sharedchannel, as proposed in this paper. Furthermore, this work focuses the simulator through a hardware implementation of the uplink relay nodes by means of the design of mmWave transcopter (Tx/Rx). On the other hand, the disadvantages of our proposed method are the half duplex mode in the architecture and fixed scenario. Nevertheless, full duplex operation and mobility in 5G network will be addressed in further research.
# A Security Framework for the Internet of Things in the Future Internet Architecture
## 4 MobilityFirst-Based IoT Architecture  
### Overview of the MobilityFirst Infrastructure  
MobilityFirst is a future Internet architecture that aims at providing fundamental solutions to the challenges facing the current Internet. The primary design goals that drive MobilityFirst are _mobility_ and _trustworthiness_, two major trends of the Internet. In order to achieve these two design goals, MobilityFirst breaks targeted specific design goals, including seamless host and mobility, no single root of trust, intentional data receipt, proportional robustness, content addressability and evolvability. These design goals come together to solve the challenges faced by the current Internet.  
Figure 3 shows that MobilityFirst introduces a new protocol stack and replaces the original \"narrow waist\" of the current Internet (i.e., TCP/IP) with a new name-based service layer, which consists of the _Name Certificate & Resolution Service_ (_NCRS_) and the _Global Name Resolution Service_ (_GNRS_). This new service layer is centered on the concept of \"flat\" security-based GUIDs for network objects, a single abstraction that serves as both the network object's identity and the public key. Various types of network entities, e.g., a smartphone, a person, a group of IoT devices, a piece of content or context, can obtain their globally unique identifiers from the NCRS, which provides translation services between human readable names and public-key based globally unique identifiers. The GNRS provides a clean separation of the identifiers and the dynamic network address locators and supports on-the-fly binding of names to network addresses as needed for dynamic mobility. Therefore, the use of the GUID at the name-based service layer enables mobility-centric services at scale and provides the foundation of a trustworthy network.  
With the name-based service layer, the MobilityFirst architecture is able to relieve or at least mitigate many pains in today's Internet. In the MobilityFirst network, due to the separation of the name and the network locator, users may request content by the content name directly, without bothering with the current network address. The routers handle the content request by querying the GNRS for  
Figure 3: The protocol stack of the MobilityFirst architecture.  
a list of the up-to-date content storage locations in a timely fashion and then fetching the content from the nearest storage location [31]. This approach also handles content mobility well with support from the on-the-fly/late binding of names to addresses and the hop-by-hop storage-aware transport protocol MFTP [32]. The GUID, which is a public key, allows MobilityFirst to integrate trustworthiness as one of the basic properties of the architecture. Deriving the identifiers in a cryptographic manner makes many security measures, e.g., authentication, accountability and encryption, intrinsic to the MobilityFirst network thus facilitating further protection against various attacks.
## 4 Simulation Results
### OP of the Secondary Network
To more clearly show the impact of \(x_{\text{R}}\) on the OP performance of the secondary sources, in Figure 6, we present \(\text{OP}_{\text{SS}_{1}}\) and \(\text{OP}_{\text{SS}_{2}}\) as changing \(x_{\text{R}}\) from 0.1 to 0.5. In this figure, \(P_{\text{PT}}\) is fixed by 10 (dB). We first see that both \(\text{OP}_{\text{SS}_{1}}\) and \(\text{OP}_{\text{SS}_{2}}\) increase as \(x_{\text{R}}\) increases, which means that the proposed scheme performs well when the secondary relays are near the source \(\text{SS}_{1}\). Figure 6 also shows that \(\text{OP}_{\text{SS}_{1}}\) and \(\text{OP}_{\text{SS}_{2}}\) are lower with higher values of \(M\), and the simulation results match very well with the analytical ones. Figure 5: OP of the secondary sources as a function of \(M\) when \(P_{\text{PT}}=10\) (dB).
# Analysis of Available Components and Performance Estimation of Optical Multi-Band Systems
## 5 Conclusions  
In this work, we studied an OMB link with an amplification scheme based on commercially available rare-earth doped fiber amplifiers for the O, S, C, and L-bands. We derived a closed-form expression for the attainable transparent reach of each band of the link (taking into account the impact of the ASE accumulation and the FWM crosstalk), and then, we proceeded to the calculation of the link's capacity and the capacity-length product.  
The proposed physical layer analysis showed that systems based on currently available components can exceed a capacity of 130 Tb/s for short distances such as 150 km and 40 Tb/s for longer ones, e.g., \(>\)2000 km. It also illustrated the fact that there is a trade-off between the modulation format and the attainable reach (as the higher cardinality modulation formats require a higher OSNIR in order to attain the same BER), which resulted in a decreased bit rate times reach product for the higher modulation formats.  
Conceptualization, D.U. and A.S.; methodology, D.U., A.S.; investigation, F.A.; resources, D.U. and F.A.; data curation, D.U. and F.A.; writing--original draft preparation, D.U., G.P; writing--review and editing, D.U., G.P.; All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The authors declare no conflict of interest.
## 6 Conclusions  
The paper presents methods that enables underwater nodes to establish communication links using a directional underwater transducer. Our approach leverages a geodesic grid to identify channels that ensure minimal overlap while maximizing coverage. We show that by using the geodesic grid, a node avoids creating a shadow zone and conserves energy by choosing contiguous beams. We then utilize the selected beams to aid nodes across the AUN in obtaining a common depth axis in a distributive manner. To simplify the analysis, a projection scheme is presented that maps the 3D underwater environment into a 2D one that preserves the SSP structure and is deemed suitable for studying the inhomogeneous effects on propagating underwater acoustic signals. The paper also presents a lightweight underwater ray classification algorithm that identifies the ray types based on their propagation path. Specifically, the classification algorithm categorizes rays into direct, reflected and a refracted ray that change the vertical direction due to SS changes along their path. The classification algorithm performance was validated in a simulated environment using actual SSP measurements. For more than 1600 randomly deployed node pairs within a range of 5 km, 96% of the rays were classified correctly. Finally, to aid nodes in tracking underwater targets or locate drifted nodes and reestablishing communication with them, we compute the location of contours between regions to aid node in deciding which type of rays is most suitable to communicate within each region. Using the different regions, it was found that only the surface reflected rays can cover all regions except the permanent shadow zone for which communication cannot be established unless the location of the node changes. Moreover, the permanent shadow zone is only observed when refraction forces acoustic signals to change the vertical direction, i.e., face a LEP. Finally, regions where direct rays and rays facing a directional reversal before they reach a bouncing surface are also identified. By exploiting these regions, underwater nodes are more capable of tracking and reestablishing communication with mobile or drifted nodes. Furthermore, we discuss the effect of angle and depth errors on the categorization algorithm.  
[PERSON] and [PERSON] contributed in conceptualization of this article. Moreover, the proposed methodology, software and simulation, validation, formal analysis, investigation, data curation, visualization and original draft preparation was conducted by [PERSON] [PERSON] helped in refining the algorithms, reviewing the results, and editing the final manuscript.  
This work is supported in part by the National Science Foundation, USA, contract #0000010465. Moreover, [PERSON] is also associated with and supported by King Fahd University of Petroleum and Minerals, Kingdom of Saudi Arabia.  
The authors declare no conflict of interest.
###### Abstract  
To increase the accuracy of indoor visible light positioning, a novel indoor visible light localization technique based on the marine predator algorithm-optimized least squares support vector machine (MPA-LSSVM) is suggested. The light signals of each reference point are recorded in the first place and a fingerprint database is created. Introduced thereafter is the marine predator algorithm, which, through iterative optimization of the hyperparameters of the least squares support vector machine, aims to establish an optimal localization model using finely-tuned hyperparameters. This culminated in the development of a positioning model, successfully attaining the objective of enhancing accuracy in positioning while minimizing time expenditure. In an indoor-positioning scene (size: 1 m \(\times\) 1 m \(\times\) 1 m), the average positioning error of the proposed positioning method is 0.041 m, and the proportion of test points with positioning errors less than 0.1 m is 96.7%.  
optical communication; visible light positioning; marine predator algorithm; least squares support vector machine; fingerprint database
## 2 Materials and Methods
### Normalized Difference Vegetation Index  
The Normalized Difference Vegetation Index (NDVI) is a unitless numerical indicator for the type of live vegetation grown over the regions which used Red and NIR band of electromagnetic spectrum [34]. It plays a vital role in the identification of healthy vegetation where live vegetation absorbed red and green with more amount of NIR light, thus appearing as deeply red in false color composite (FCC). Denser plants over the region appear darker in red and vice versa, whereas sparse or unhealthy vegetation mostly reflect the visible light and a lower amount of NIR light, appearing grey in tone. It also depicts the presence of chlorophyll pigments within the plants, and provides an anomaly of the growing season which ultimately provides clues for desertification and drought conditions. The relationship between the production of vegetation and NDVI was well established theoretically and empirically by [PERSON] (2017) [44]. The NDVI can be mathematically defined as follows:  
\[\text{NDVI}=\frac{\text{NIR}-\text{R}}{\text{NIR}+\text{R}} \tag{1}\]  
The value of NDVI ranges from \(-1\) to \(+1\). The increasing values from 0 to \(+1\) depict the presence of vegetation, and near \(+1\) indicates the denser vegetation covered in the area. If the value decreases beyond 0 to \(-1\), it represents the present of bare land, water bodies, ice, snow and manmade  
Figure 1: Location and zone ranges of elevation in study area.  
features [10, 45]. In this study, the Digital Number (DN) value of the NDVI images are categorized from low density to high density as per Table 1[46, 47].
## 4 Simulation Results
### Case 2: Both PMSMs Have the Same Speed Under Different Load Torques  
In this case, the speed of the PMSMs is 2000 rpm with load torques of 6 and 12 Nm. The second carrier harmonic is partially cancelled but not completely eliminated, and it still appears in the frequency spectrum, which is shown in Figure 9b, because the coefficients of the carrier harmonics are unequal due to the differences in the modulation indices and phase currents of the PMSMs. The RMS values of the phase currents are 46.7 A and 93.3 A. The second carrier harmonic is reduced, and the sixth carrier harmonic is completely eliminated, resulting in a reduction in the RMS value of the capacitor current from 87 A to 36 A.  
Moreover, the dc-link capacitor current is simulated for a scenario where one PMSM (PMSM-1) has a constant speed of 2000 rpm and a constant load torque of 9 Nm, and the other PMSM (PMSM-2) has varying load torques with a constant speed of 2000 rpm, as shown in Figure 10. The simulation results show that the dc-link capacitor current increases when PMSM-2 is operating if there is no phase difference between the carrier waves. On the contrary, the dc-link capacitor current decreases when PMSM-2 operates if there is a phase difference between the carrier waves. The dc-link capacitor current of two motor systems is always higher than that of one motor system when there is no phase shift. Conversely, the dc-link capacitor current of two motor systems is always lower than that of one motor system when there is a phase shift.
## 4 IRT Different Case Studies from Diagnosis to Protection Interventions  
### Decay Diagnosis/Identification of Different Construction Phases  
Diagnosis is one of the first phases of a conservation project. It is achieved through a survey in situ, including inspection and non-destructive investigation, followed by sampling and further analysis. A combination of various NDTs is necessary in order to extract significant and useful results. As a recent example shows, for the case of Kaisariani Monastery (11 th or 12 th cen.), a UNESCO mid-byzantine Monastery, where after an in-situ optical inspection, different NDTs were applied, such as: Ground-penetrating Radar (GRP), IRT (FLIR B200 Western, Agerma Sweden, 7.5-13 \(\upmu\)m), Fiber Optics Microscopy (FOM) and Schmidt rebound Hammer test.  
In this case, the main interesting finding was that, with the aid of NDTs, especially with the application of IRT, it was possible to identify the different construction phases based on the different temperatures of the different materials used, like mortars and ceramic bricks (Figure 8). For example, restoration bricks were identified, which presented different temperatures to the authentic ones. Restoration bricks presented lower temperatures (-17 \({}^{\circ}\)C) in comparison to the historic ones (-21 \({}^{\circ}\)C). The date the thermogram was taken was 17.02.2014, with air temperature T = 12 \({}^{\circ}\)C, RH = 52%.  
Moreover, the presence of moisture and different types of surface decay, were also investigated [20].
# Investigation of Segmented Halbach Array Design for Passive Magnetorheological Brake System
## 6 Conclusions  
This research validates the potential of a segmented Halbach structure in a self-sustaining magnetorheological brake for improving magnetic performance. By carefully optimizing parameters such as the array configuration, and the magnet spacing and dimensions, the design achieves a highly concentrated magnetic flux on one side of the array. Compared to conventional permanent-magnet Halbach configurations, the proposed segmented Halbach array offers several key advantages, including a 50% increase in flux density and a 75% reduction in magnet material usage. The optimized structure results in a stronger, more uniform magnetic field with the proposed Halbach configuration and offers a simple and reliable solution for braking performance in compact brakes. This advanced configuration enhances braking torque up to 2 times compared to conventional Halbach array brakes and ensures higher flux distribution efficiency. Future research may explore further optimization techniques and perform experimental investigations of the proposed design in the development of hybrid braking technology to offer enhanced performance and energy efficiency.  
Figure 12: Braking torque among the types of magnetorheological brakes, the conventional PM Halbach structure in a brake, and the proposed segmented Halbach structure in a brake.  
**Author Contributions:** Conceptualization, Y.S.; Methodology, Y.S. and M.B.; Software, M.B.; Validation, M.B.; Formal analysis, M.B.; Investigation, M.B.; Resources, Y.S.; Writing--original draft, M.B.; Writing--review & editing, Y.S.; Supervision, Y.S.; Project administration, Y.S.; Funding acquisition, Y.S. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was financially supported by the National Science and Technology Council, Taiwan (project no. NSTC 113-2221-E-027-040-MY2).  
**Data Availability Statement:** The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.  
**Conflicts of Interest:** The authors declare no conflict of interest.
# Signature-Based Security Analysis and Detection of IoT Threats in Advanced Message Queuing Protocol
## 5 Attack Description and Explanation
### Experiment Setup  
The Internet of Things (IoT) testbed used in this study simulates a real-world deployment of IoT networks. The testbed consists of various IoT devices, an AMQP server, an attacker's computer, network hardware, and the AMQP communication protocol.  
Figure 1: Normal network traffic packets for AMQP.  
Figure 2: Normal network data exchange traffic for AMQP.  
* **Hardware Configuration**:
* The primary lab machine is a Dell XPS Windows 11 laptop with 1 TB SSD, an Intel Core i5-11270U processor, 16 GB of RAM, and a 4 GB NVIDIA RTX GPU.
* Virtual machines (VMs) are managed using VirtualBox. An Ubuntu-based VM serves as the AMQP server, with 4 GB of RAM, 20 GB of storage, and 2 CPU cores.
* Each IoT device is simulated using a VM allocated 2 GB of RAM, 15 GB of storage, and 1 CPU core.
* Two attacker computers are configured with 4 CPU cores, 8 GB of RAM, and 80 GB of storage for launching attacks.
* **Network Configuration*
* The virtual machines reside in a private network configured within VirtualBox's internal networking mode to ensure isolated, controlled traffic flow.
* The AMQP broker (RabbitMQ server) is assigned a fixed private IP (e.g., 192.168.180.230), with all IoT devices and attacker nodes connected through a virtual LAN (vLAN).
* Packet capture and analysis were performed using Wireshark and tcpdump within the virtualized network.
* **Platform for Simulating Attacks** The attack modeling and execution were performed within a controlled VirtualBox-based network, ensuring traffic flows accurately reflect AMQP-specific attack scenarios. The Ettercap tool was employed for MiTM attacks, while Hping3 and BruteMQ were used for DoS and brute force attacks, respectively.  
This setup allows the simulation of real-world attacks against AMQP-based systems while monitoring and analyzing the network traffic.