esa-sceva/satcom-chunk-collection huggingface dataset:
# MSC-Net: Multitask Learning Network for Retinal Vessel Segmentation and Centerline Extraction
###### Abstract
In the work of single centerline extraction, the centerline can be obtained after the skeletonization process of pre-segmented blood vessels [28]. The main disadvantage of this method is that inaccurate blood vessel segmentation may lead to skeletonization errors. [PERSON] et al. [29] proposed the method of determining the retinal skeleton in a direct way through random watershed transformation. In this method, the division area has no limit, which may generate wrong branches. Therefore, some methods combine segmentation and centerline extraction. [PERSON] et al. [30] proposed a clDice loss function to realize the constraint of the centerline on blood vessels, but they only focus on the segmentation task, and the centerline is only an intermediate result. [PERSON] et al. [31] used the Inception architecture without a pooling layer to classify each pixel in the image block and extract the blood vessel centerline. [PERSON] et al. [5] performed blood vessel segmentation and centerline generation based on the Capsule Network combined with the Inception architecture. However, these methods usually do not take into account the direct constraint relationship between the two tasks. This paper proposes a multitask learning network to combine the two tasks, blood vessel segmentation and centerline extraction. We specially design the network and loss function to better discover the topological relationship between these two tasks and realize their complementary features. In summary, the main contributions of this article are as follows:  
1. We propose a multitask learning network for retinal vessel segmentation and centerline extraction, named MSC-Net. The multitask learning with the dual-branch design can complete two tasks at the same time, and the fusion path can effectively aggregate features. 2. We design a channel and atrous spatial fusion block (CAS-FB) to solve the feature calibration and fusion of different tasks in different sizes in the fusion path. The channel attention module can effectively calibrate the features of different tasks, and the spatial attention module can aggregate the features of different scales of blood vessels. 3. Unlike the original clDice loss, which is only applied to the optimization of segmentation tasks, we apply clDice to segmentation and centerline extraction at the same time. Therefore, the vessel segmentation and centerline result can be mutually constrained to ensure the consistency of the topology.
# Detecting Malicious Devices in IPSEC Traffic with IPv4 Steganography
## 3 IPsec-Based Network Steganography
### Proposed Method
These bits indicate whether the information being transmitted pertains to the first, second, or third segment of the MAC address. If a packet does not contain any part of the MAC address, two zero bits are inserted at the most significant positions of the time-to-live field. This arrangement leads to four possible scenarios:  
* The identification field carries the first 16 bits of the MAC address, and the two most significant bits of the time-to-live field are set to 01. * The identification field carries the second 16 bits of the MAC address, and the two most significant bits of the time-to-live field are set to 10. Figure 7: Normal traffic packets sequence. * The identification field carries the third 16 bits of the MAC address, and the two most significant bits of the time-to-live field are set to 11. * The identification field does not include MAC address data, and the two most significant bits of the time-to-live field are set to 00. After receiving the 48-bit MAC address, the device records it in a table of corrupted MAC addresses. This data is retained until the network controller notifies the hosts that the device with the specified MAC address is no longer considered corrupted. The packet sequence for sending the MAC address is illustrated in Figure 8.  
This MAC address-based approach can alert the network controller about compromised devices. The end host can communicate with the network controller and transmit the MAC address associated with potentially unauthorized access. Alternatively, routers can adopt this mechanism by halting traffic forwarding and sending the MAC address to the controller even before allowing packet forwarding to the end host. As a result, security is enhanced throughout the entire network. The presented approach bandwidth is equal to a maximum of 3 bytes by utilizing identification and time-to-live fields.
## 4 Implementation
### FAST-DSCR: Discrete Model with Fast Rotation Transformation  
The function FAST-DSCR, shown in Figure 8, implements (31) and improves on the previous one by employing a custom matrix multiplication with fewer operations. So far all the matrix multiplications were conducted with the general matrix multiplication rules that use all the elements of the matrices involved. However, matrices \([T_{k}]\) and \([\Delta T_{i}]\) can be considered sparse and their use can be simplified considering only the minimum elements involved. In particular, only the upper left corner of (11) (regarding the stator values) actually operates a rotation with sine and cosine, while the rest of the elements are either 0 or 1, not requiring any mathematical operation.The rotation matrix multiplication is therefore replaced by a much faster custom function that involves only the minimum number of operations indicated in Figure 8 with dotted squares.  
The blocks that in the previous models generated the full rotational matrices are here substituted by similar ones that just output the sine and cosine values.  
Figure 6: Discrete time model with fast matrix inversion: INV-DSCR.  
Figure 7: Discrete time model with rotor reference frame integration: ROTOR-DSCR.
# A Survey on Robust Video Watermarking Algorithms for Copyright Protection
## 5 Robust Watermarking Algorithms Based on Compressed Videos
### MPEG-Based Watermarking Algorithms
The algorithm can eliminate the error propagation caused by watermark in normal video and use error propagation caused by watermark adjustment to protect video content. In a past paper [78], the embedding strength of the watermark was adjusted according to local image characteristics, and then the spatial spread spectrum watermark was directly embedded into the MPEG-4 bit stream by modifying DCT coefficients. In another past paper [79], the scene change detection was adopted to select key frames in the compressed domain, and local areas of these key frames were selected based on the extraction of feature points. On the basis of the [PERSON]'s perceptual model, the watermark embedding process is achieved adaptively. [PERSON] and [PERSON] [80] proposed two watermark embedding schemes: Human visual system for achieving high visual quality (HVSVIS) and human visual system for achieving better embedding capacity (HVSCAP). The HVSVIS method embeds watermark information in middle-frequency DCT coefficients realizing high visual quality, and the HVSCAP method achieves higher embedding capacity by maintaining better visual quality. The summary comparison of several watermarking algorithms based on MPEG is shown in Table 9.
# A Study on the Applicability of Waste Glass Wool and Waste Mineral Wool as Fiber Reinforcement
## 3 Methodology  
### Slump Test and Air Content Test of Fresh Concrete  
Slump is a property that is directly related to the workability of concrete and affects the compatibility and pumpability of the mixture. Therefore, excessive compression energy may be required when placing concrete mixtures that do not satisfy the designed slump, which may induce material separation of concrete, resulting in a decrease in strength and durability. As the addition rate of fibers in concrete increases, the viscosity of the mixture increases and the slump decreases [26]. Therefore, it can be said that fiber-reinforced concrete shows a different slump behavior from ordinary concrete, and as the fiber addition rate increases, measures such as increasing the unit water or increasing the use of water reducer are applied to satisfy the design slump. This test was conducted for the purpose of evaluating flow properties of fresh concrete according to the type and addition rate of waste fiber wool by KS F 2402. The air content of concrete has a great influence on durability such as freezing-thawing resistance as well as strength. If the air content is excessively dispersed in concrete, the strength of the concrete will decrease significantly, making it difficult to meet the strength standards, and it may also have a negative impact on durability. Thus, when concrete is placed in the cold region, an air entraining agent is added to most concrete to ensure freezing-thawing resistance [27]. It is commonly known that the freezing-thawing resistance of concrete is the best at the air content within 6% [28]. The air content is a measure to evaluate durability of concrete when it is not hardened. This test was conducted to examine the change in air content when waste glass wool and mineral wool were added to the concrete. The test method was conducted according to KS F 2421.
## 2 Sensor Design
### Temperature Sensitivity  
After developing and designing the patch, its characteristics were determined. That means the patch responses to temperature, load, combined temperature and load, and dynamic load were investigated. The patch responses to these parameters describe the patch characteristics. A total number of 13 patches were designed to carry out the different tests.  
Before loading the patch, the effect of thermal influence on the patch was characterized. It is very important to determine this parameter. Typically, FBG sensors measure both temperature and strain. In order to achieve a pure strain measurement, the measured values obtained must be corrected by the temperature-correlated strain.  
The temperature tests were carried out with patches with embedded acrylate-coated FBGs; the samples were investigated in a temperature chamber in the range of \(-40\)\({}^{\circ}\)C to \(+60\)\({}^{\circ}\)C. The patches showed linear temperature sensitivity over the whole temperature range. The temperature sensitivity could be determined to be 24 pm/K.  
Temperature compensation during mechanical loading has been performed utilizing an additional temperature sensor.
## 3 Results
### Quantitative Analysis Using SEM-EDX  
The surface morphology of the _P. harmala_ seeds before and after doping of the pure zinc (\(\upmu\)g/g), as well as the chemical composition, were investigated using the energy-dispersive X-ray (EDX) and SEM. The X-rays radiations released from the sample's surface were identified via a Si (Li) detector (30 mm\({}^{2}\)). An Oxford-Instruments X-MAX-N-20 EDX-instrument connected with a SEM functioned at 30 keV was utilized to evaluate chemical composition of all seed samples. A spectrum of the _P. harmala_ seed sample-(\(\upalpha\)) is presented in Figure 10a, showing the existence of Mg, Al, Na, Si, Sr, K, Ca, Rb, Cu, Pb, and Fe. The elements, Ca, Fe, Mg, and Cu are detected as major, and Na, Al, Si, Sr, K, and Rb are identified as minor ingredients. Furthermore, light elements including Li, and C were not detected by EDX due to its detection constraints. The morphology of all the seed samples was examined using SEM. In Figure 10b, we show an SEM micro-image of the surface of the seeds pallet with 4 \(\upmu\)m high resolution showing the surface morphology of the _P. harmala_ seed sample-(\(\upalpha\)). Prominent various grains correspond to different elements. The calcium sulfate and silica grains are observed to show a sufficient amount of calcium (Ca) and silicon (Si) in the sample.  
In Figure 11, we present the chemical composition comparison in \(\upmu\)g/g of analytical techniques such as CF-LIBS, XRF, and EDX. Interestingly, Si, Mg, Ca, Fe, K, Pb, Cu, and Sr are successfully identified by all the analytical techniques; however, some trace elements present in the samples were only identified by individual techniques due to their detection constraints. For instance, different elements including Zr, Ru, and Mn were detected only by XRF; similarly, Li, and C by LIBS, and Rb were only detected by EDX due to the elemental homogeneity and detection limits. Therefore, in a particular range, results show that Mg, K, Si, Ca, Fe, and Cu are the major identified elements of the seed samples.  
Figure 10: (**a**) EDX spectrum of the _P. harmala_ seed sample-(\(\upalpha\)) at 30 keV; (**b**) SEM image of the _P. harmala_ seed sample-(\(\upalpha\)) showing the surface morphology.
## 6 Prototype Experiment
### Single-Leg Free-Falling Experiment  
The single leg of the hexapod robot weighs 20 kg. In the preliminary experiment, the free-fall experiment was carried out without the impedance control method, and the foot-end touchdown force was recorded by the force sensor. The process of the foot contacting the ground is shown in Figure 23. The experimental results are shown in Figure 24. The maximum foot-end touchdown force is approximately 1900 N, indicating that the leg has insufficient compliance. The time required for the foot-end contact force to reach a stable state is approximately 1.3 s, and a rebound phenomenon occurs. This is mainly because the high stiffness of the leg leads to a large impact force when contacting the ground, thus causing multiple rebounds.  
Figure 23: Pure positional control of leg movement processes.  
Figure 22: Single leg prototype diagram.  
When the robot operates in a tripod gait, a single-leg misstep (foot slip or air step) may lead to instability and result in a significant impact force between the foot-end and the ground. Therefore, a force-based impedance control strategy is introduced to reduce the impact during foot-ground contact. In this section, we designed a single-leg free-fall scenario to simulate the foot-end impact caused by an air step in the tripod gait.  
After applying force-based impedance control to the leg, the free-fall process is shown in Figure 25, and the experimental results are shown in Figure 26. The maximum impact force drops to approximately 850 N, which is only 45% of the maximum impact force without impedance control. Meanwhile, the stabilization time is reduced to 33% of the original time, and no rebound phenomenon occurs. The experimental and simulation results are consistent with the overall trend. The results show that the force-based impedance control significantly enhances the mobility of the robotic leg and impact resistance and enables it to reach a stable state more quickly.  
Without the force-based impedance control strategy, the maximum foot-end contact force during free-falling reaches up to 1900 N, which is likely to damage the internal mechanical structure of the leg. To mitigate the impact of touchdown force, a desired contact force of 200 N is set in this study. After introducing the control strategy, the peak contact force is significantly reduced to 800 N and eventually stabilized at 200 N, effectively alleviating the structural damage caused by impact. The experimental results verify the  
Figure 24: No impedance force at the foot-end of the falling body in the vertical direction.  
Figure 25: Single-leg free-fall motion process without impedance control.  
effectiveness of the proposed control strategy in mitigating landing impacts and achieving the expected control objectives.
# A Cascaded Ensemble of Sparse-and-Dense Dictionaries for Vehicle Detection
## 3 Training of CESDD
Level 1 consists of dictionary pairs of subcategories from relatively standard vehicle and background types with clear specificity: fully visible (FV) vehicles and partly occluded (PO) vehicles for vehicle category, and general background (GB) for background category. Level 1 ensemble is responsible for producing initial predictions which are then handed over to Level 2 of the cascade for refinement. Level 2 consists of dictionaries of relatively vague types: largely occluded (LO) vehicles for vehicle category, and vehicle parts (VP) for background category. The usage of Level 2 ensemble differs from Level 1: each of the samples tagged as positive in initial predictions is to be represented over dictionary pairs of type VP, producing corresponding reconstruction residues; the minimal one of these residues are to be compared with the minimal one from vehicle category in Level 1; if the minimal residue from VP is smaller, then the initial prediction should be corrected as negative. This refinement process is identically carried out over samples initially predicted as negative: each of these samples is to be represented over dictionary pairs of LO vehicle subcategories; the minimal reconstruction residue from these subcategories is to be compared with the minimal one from GB subcategories in Level 1; if the minimal residue from LO vehicle is smaller, then the sample should be regarded as positive. This cascade-styled classification scheme exhibited its advantage in reducing false positives during detection, as shown in Figure 2; its classification performance is illustrated in subsequent experiments.
# Internet of Things and Blockchain Integration: Security, Privacy, Technical, and Design Challenges
## 4 RQ 3--BIoT Integration: Future Concerns and Trends
### Quantum Computing  
Although BC-based frameworks can provide edge computing systems with a greater level of security, super-scale data integrity necessitates fast hash computation. To overcome this challenge, quantum computers must be used to build adaptable systems to data properties [82]. Quantum dot architecture can help with the creation of new hashing and encryption mechanisms that make data integrity more difficult. To offer all stakeholders a safe environment that facilitates this paradigm change, the privacy and trust models established for serverless computing require special consideration, which might represent a challenge in the future [82]. Quantum computing is quickly increasing the processing capacity of contemporary computers, posing major security concerns for public-key cryptography-based BC systems. BC systems are predicated on the idea that traditional computers can swiftly decrypt large quantities. As a new technology, quantum computing can solve extremely complex matters very quickly. As a result, it poses a severe data security danger to BC technology. One proposed solution to this problem is to use quantum-resistant encryption instead of traditional digital signatures [77].
# Devising Mobile Sensing and Actuation Infrastructure with Drones
## 5 Conclusions  
We have designed and implemented DaaG, a drone that provides connectivity between separate networks as a mobile gateway. Our simulation and experiment results show that DaaG can connect between the sensor network and actuator network. Furthermore, DaaG uses various algorithms to connect these separate networks efficiently.  
There is a large variety of possible application scenarios for the system. The drone can fly to dangerous regions that people cannot reach. Therefore, a disaster situation is the most appropriate example for this scenario. Another example is an agricultural application of an IoT system. Examples of sensing devices in this scenario would be for light, temperature and moisture. Possible actuators would be sprinklers or spraying fertilizers and pesticides. With DaaG, we believe more applications in addition to these scenarios can be realized.  
The smart and path-planning algorithm in DaaG can be improved, for example to be able to run appropriately in an environment in which the system does not have knowledge of the service type, nor the map of the actuators, which is our future work.  
**Acknowledgments:** The first three authors equally contributed to this paper. This research was supported by the Unmanned Vehicles Advanced Core Technology Research and Development Program through the Unmanned Vehicle Advanced Research Center (UVARC) funded by the Ministry of Science, ICT and Future Planning, the Republic of Korea (NRF-2016M1B3A1A01937599).  
**Author Contributions:** [PERSON] managed the overall procedure of this research. [PERSON], [PERSON] and [PERSON] designed and implemented DaaG. [PERSON], [PERSON], [PERSON] and [PERSON] designed and performed the experiments. [PERSON] designed and performed the simulations. [PERSON] analyzed the data. [PERSON], [PERSON] and [PERSON] wrote the paper.  
**Conflicts of Interest:** The authors declare no conflict of interest.  
Figure 12: Delay measurement from the experiment.
## 3 Results and Discussion
The correlation analysis showed a high degree of interdependence between the content of heavy metals in triticale grains obtained under the influence of fertilizer granulates and the uptake of cadmium, nickel and copper, as well as a very high degree of interdependence between the content and uptake of zinc. The value of the correlation coefficients ranged from \(r=0.491\) to \(r=0.849\). The highest value of the correlation coefficient was found in the triticale grain between the content and uptake of lead, chromium, and zinc (0.829; 0.840; 0.849). It was found that the relationship between the content and uptake of heavy metals by test plants increased under the influence of increasing doses of applied fertilizer granulates. Statistical analysis of the obtained test results confirmed significant relationships between the content and uptake of heavy metals by rape seed and triticale grain. The literature also pointed out the relationship between the content of micronutrients in plants and the activity of enzymes in the soil [39,40,41]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Metal**} & \multicolumn{4}{c}{**Correlation between the Content and Intake of Heavy Metals**} \\ \cline{2-5}  & \multicolumn{2}{c}{**Rape Seed**} & \multicolumn{2}{c}{**Triticale Grain**} \\ \cline{2-5}  & \(p\) & \(r\) & \(p\) & \(r\) \\ \hline Cd & 0.026 & 0.653 & 0.104 & 0.491 \\ Cu & 0.092 & 0.507 & 0.007 & 0.726 \\ Cr & 0.002 & 0.798 & 0.001 & 0.840 \\ Ni & 0.002 & 0.906 & 0.016 & 0.673 \\ Pb & 0.001 & 0.806 & 0.002 & 0.829 \\ Zn & 0.036 & 0.607 & 0.002 & 0.849 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Correlation between the content and uptake of heavy metals by test plants. Figure 1: Rectilinear relationship between the content and uptake of heavy metals by rape seeds under the influence of applied fertilizer granulates in mg-kg\({}^{-1}\) DM. Figure 2: Rectilinear relationship between the content and uptake of heavy metals by tritticale grain under the influence of applied fertilizer granulates in mg\(\cdot\)kg\({}^{-1}\) DM.