esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Existing Leak Detection and Localization Methods
### Methods Based on Knowledge
#### 2.3.2 Pattern Recognition  
The detection principle of the pattern recognition method is based on transient feature extraction and structural pattern recognition for the negative pressure wave caused by a pipeline leak [31, 32]. Since it is quite different from that caused by adjusting pumps and valves, describing the negative pressure wave by pattern recognition method and building classification system of wave structure are able to effectively distinguish between normal adjustment states and leak states. This type of detection method can effectively reduce the false alarm rate and the missing detection rate, and improve the accuracy of leak detection.
## 3 Tests Results and Analyses
### Analysis of the Grouting Seepage Pressure in the Rough Fracture  
A series of curves was acquired on the basis of the data from the pressure sensors in the orthogonal experiment. The curves of seepage pressure had good regularity, the seepage pressure change curve in the orthogonal experiment on grouting in a rough fracture with flowing water were divided into \"single peak types\", \"multi-peak types\", and \"platform types\". The change curves of seepage pressure were divided into three types, which are shown in Figure 9.  
Figure 8: Images of grout diffusion along rough fracture. (**a**) Trial No.3. (**b**) Trial No.6. (**c**) Trial No.12. (**d**) Trial No.13. (**e**) Trial No.14.  
(1) \"Single peak type\" change curve of seepage pressure  
The basic characteristics of the \"single peak type\" are shown in Figure 9a. By regulating the velocity of the flowing water to the level of the test, the model of the simulated rough fracture became full of water. After starting grouting, the grout diffused to the measuring point during the prophase of grouting, and the seepage pressure had little change in this process. The grouting pressure increased with the consolidation of grout, and the seepage pressure reached the peak value while the grout filled the whole fracture. Then, the seepage pressure began to decrease after the grouting ended.  
(2) \"Multi-peak type\" change curve of seepage pressure  
The seepage pressure field of trials No.2, No.6, No.7, and No.13 in the orthogonal experiment belonged to the \"multi-peak type\" change curve of seepage pressure. Representatives of the \"multi-peak type\" are shown in Figure 9b,c. The basic features of the \"multi-peak type\" were as follows: The grout was diffused under grouting pressure and flowing water. The seepage pressure increased to the peak value as time went by, and the fracture began to be blocked by the grout at the same time. Then, the seepage fracture declined since the grout had not been condensed completely, and this was washed away by flowing water. Afterwards, this process repeated until the grout plugged up the fracture completely, and this led to a multi peak value.  
(3) \"Platform type\" of the seepage pressure change curve.  
There were five groups with the \"platform type\" change curve of seepage pressure in the orthogonal experiment: Trials No.4, No.8, No.9, No.15, and No.16. A typical \"platform type\" change curve of the seepage pressure is shown in Figure 9d. The seepage pressure increased to the first peak value in early grouting. Then, the value had little change for a period of time. The reason for this phenomenon was that the grout did not spread to the whole fracture. Chemical grout spread to each measurement point first. After that, the grout diffused to the boundary of the fracture and the seepage pressure showed little change in the meantime. After the grout spread to the boundary, the passage of water was blocked which caused the seepage pressure to rise. With the end of grouting, the value of seepage pressure started to fall.  
Figure 9: _Cont._
## 4 Test Results and Discussion
### Numerical Simulation of the Strengthening Approach  
The efficient method of the finite element and, in particular, the Concrete Damage Plasticity (CDP) model as it is implemented in ABAQUS has been employed by the authors [43] in order to provide additional validation to the acquired experimental data. This way, a deeper understanding of the described strengthening approach with the application of C-FRP is achieved, and the results are presented in [43].  
The joints were similar with the ones tested herein, and they were either unstrengthened or retrofitted with C-FRP ropes. Based on the results of the study, the following remarks were drawn: (a) The differences between the experimental and numerical results were small, considering the load-displacement curves, the maximum principal stress, and the shear deformations. It shows that the material input in the program and the FE modeling have been accurately performed. (b) The only considerable difference was found in the shear deformation of specimen without C-FRPs. (c) Further, the importance and effectiveness of the application of FRP ropes for the improvement of the seismic response of the joints have also been proved. (d) The cracking patterns of the examined specimens, as predicted using the finite elements in specimens, are very close to those of the experimental ones. This shows that the used CDP can accurately predict the crack propagation in concrete, and it can simulate the concrete's triaxial behavior accurately. (e) The favorable influence of the ropes is evaluated based on their real characteristics in order to achieve a more realistic prediction of SFRC behavior under compression and tension. The cyclic loading tests of retrofitted joints exhibit improved hysteretic responses in terms of stiffness, load-bearing capacity, deformation, and cracking behavior.  
The developed nonlinear FE analysis accurately predicts the overall hysteretic response of joints and the beneficial effect of the added FRP ropes. From the cases examined in this work [43], it is yielded that the values for the maximum loads per loading cycle as predicted from the numerical analysis closely match to the corresponding experimental ones with a divergence up to \(\pm 2\%\). Comparisons between the test and numerical results reveal that the developed nonlinear FE analysis with a smeared crack model that takes into account the tension softening and residual stiffness effect accurately predicts the hysteretic response of realistic concrete joints with steel reinforcement [43].
## 3 The Proposed Method
### Learnable Polar Transformation Module  
Regarding the imbalanced class distributions in fundus images, OC pixels are more likely to be misclassified. M-Net [6] segmented the OC and OD in the polar coordinate space to alleviate this problem. However, M-Net takes polar transformation as a pre-processing process without learned parameters. With the hyper-parameter being not optimal for segmentation evaluation and optimal training, features extracted by them cannot exploit the full supervision. To overcome the limitations of using the original images, we designed a learnable polar transformation module (LPTM). As visualized in Figure 3, our LPTM  
Figure 2: The architecture of our proposed Polarformer.  
consists of a polar origin detector, which detects the origin of the polar transform, and a polar converter transforms the original images into a polar representation.
## 2 Materials and Methods
### Sample Analysis  
#### 2.4.1 Fatty Acid (FA) Profile Determination  
The total fat content was determined using a milk analyzer based on Fourier transformed infrared (FTIR) technology (MILCOSCAN-FT1-FOSS, Hillerod, Denmark). The FA profile was determined in all milk samples according to [PERSON] et al. [38] through the preparation of fatty acid methyl esters. Briefly, 8.5 mL of milk and 15 mL isopropanol were shaken into a separating funnel and then 11.25 mL hexane (three times) was added, and the mixture was shaken again. The hexane layer (20 mL) was separated after centrifugation (2520\(\times\)\(g\) for 5 min at 5 \({}^{\circ}\)C) and it was evaporated after the addition of 7.5 mL 0.47 M aqueous Na\({}_{2}\)SO\({}_{4}\). To 100 mg lipid were added 5 mL hexane. The mixture was vortexed and 0.2 mL of a mixture of 11.2 g KOH in 100 mL of methanol was added, then it was vortexed again and allowed to react for 5 min. Then, 0.5 g NaHCO\({}_{4}\)\(\times\)H\({}_{2}\)O was added and the mixture was centrifuged for 5 min (5000\(\times\)\(g\) at 25 \({}^{\circ}\)C). The supernatant layer was analyzed by gas chromatography using an Agilent 5975 C GC gas chromatograph (Agilent Technologies, Centerville Road, Wilmington, DE, USA) equipped with a Supelco SP Omegawax 320 capillary column (30 m \(\times\) 0.32 mm i.d. with 0.25 \(\upmu\)m film thickness, and a flame ionization detector where helium was used as a carrier gas and injector temperature was at 240 \({}^{\circ}\)C. The sample split mode was 1/5. The initial column temperature was 70 \({}^{\circ}\)C for 5 min and then increased at a rate of 20 \({}^{\circ}\)C/min to a maximum temperature of 160 \({}^{\circ}\)C, where it remained for 3 min. Then, the temperature increased at a rate of 5 \({}^{\circ}\)C/min to a maximum temperature of 240 \({}^{\circ}\)C. The identification of the compounds was conducted using Sigma FAME standards with known concentrations. All samples were analyzed in triplicate.
# Towards Online Estimation of Human Joint Muscular Torque with a Lower Limb Exoskeleton Robot
## 4 Conclusions  
This paper proposed a novel human lower limb JMT estimation solution based on an IDA. The method has two main parts: the sensing system and the inverse dynamic approach. The embedded sensing system makes the exoskeleton easier to use than the popular EMG based devices. All subjects only need several seconds to put on the exoskeleton and input his/her weight and height; no electrodes or other sensors are required to be fixed onto the human body. Comparison experiments show similar outputs to an independent motion analysis system. According to the quantitative analysis of the two outputs from the exoskeleton and the MAS, the result shows accordance accuracy with different subjects in different motions, which indicates the individual independent character of the proposed method and its adaptability to a variety of motion patterns. Benefitting from the measurement of the FCF, the shortening of the kinematic chain helps to reduce the computational complexity through the strategy of factorizing the JMT into mass-induced one, and FCF-induced one cancels the necessity of a finite-state-machine and ensures the continuity of the JMT output.  
This study only investigated motion in the sagittal plane. In the future, we want to explore this method to random motion in \(3D\) space. In that time, the side-sway and supination/pronation of the hip joints should be measured, and the \(6D\) force/torque of the feet should be measured. The IDA equation should take the coronal and frontal motion into account. In addition, automatic identification of the individual parameters may help to further improve the accuracy.  
[PERSON] conceived the method and wrote the paper; [PERSON], [PERSON] and [PERSON] helped to modify it; [PERSON] performed the experiments and analyzed the data; [PERSON] contributed theoretical justification and reference materials. All authors have read and approved the final manuscript.  
This research was funded by Shenzhen Peacock Plan (KQTD2016112515134654), National Natural Science Foundation of China (No. U1713222, No.61773139 and No.61473015), and Natural Science Foundation of Heilongjiang Province, China (No.F2015008).  
The authors declare no conflict of interest.
# Analysis of Weighted Factors Influencing Submarine Cable Laying Depth Using Random Forest Method
## 2 Materials and Methods
### Method
#### 2.3.1 Improved Seagull Optimization Algorithm (ISOA)
The distance factor is updated along with the position update process, and the formula is as follows: \[d^{*}=\lambda\times d\] (6) Here, \(d^{*}\) is the distance factor for updating the position, \(d\) is the current distance factor for the position, and \(\lambda\) is a decay factor between 0 and 1. Levy Flight Strategy and Metropolis Criterion: The Levy Flight strategy and Metropolis criterion are incorporated to help the algorithm escape from local optima. The Levy Flight strategy allows for a random search at different scales, combining long leaps in a large range with short steps in a small range to enhance the algorithm's global search capability [25; 26; 27]. The formula for the Levy Flight strategy is as follows: \[D_{e}(x)=D_{s}(x)+|C_{s}(x)+M_{s}(x)|\times L(\delta)\] (7) Here, \(D_{e}(x)\) is the new position after the search. \(D_{s}(x)\) represents the distance between the current individual and the best position and \(C_{s}(x)\) is a random value that ensures that the seagulls do not collide. \(M_{s}(x)\) represents the direction of the individual relative to the best seagull. \(L(\delta)\) is the core formula in the Levy Flight strategy, which generates random search steps at different scales. It allows individuals to make long leaps over a wide range and short steps in a smaller range, thereby enhancing the global search ability of the algorithm and preventing it from getting stuck in local optima. \[L(\delta)=r_{1}\times\left[\,\Gamma(1+\beta)\times\sin\!\frac{\pi\beta}{2}/\Gamma ((1+\beta)/2\times\beta\times 2^{\frac{\ell-1}{2}})\,\right]^{1/\beta}/|r_{2}|^{1/\beta} \tag{8}\]  
Here, \(r_{1}\) and \(r_{2}\) are random values between 0 and 1 and \(\beta\) represents the value influencing the distribution of flight routes, typically set to 1.5. During the optimization process, some individuals in the population may explore poorer positions. To maintain population diversity, the Metropolis criterion is employed, which allows these poorer individuals to be accepted with a certain probability. This helps the algorithm better explore the solution space. The formula for the Metropolis criterion is as follows:  
\[P=\min(1,\exp[(f^{*}-f)/d]) \tag{9}\]  
Here, \(P\) represents the probability of accepting the new solution, \(f^{*}\) represents the fitness value of the new solution,\(f\) represents the fitness value of the current solution, and \(d\) is the distance factor. By combining these two methods, it is possible to effectively enhance the global search capability, enabling the algorithm to find better solutions.
# The Role of the Directivity of Various THz Detectors in Multiplexing Systems
###### Abstract  
Many modern and future systems, based on the wireless communication at the THz frequencies, could benefit from multichannel transmission. One of the possible approaches is to (de)multiplex several separate signals to and from a single transmission channel using dedicated diffractive optical elements. Proper selection of receivers for such systems is crucial and strongly depends not only on the frequencies used but also on the geometry of the setup. In this article, we present a complex analysis of the applicability of various detectors for the characterization of highly convergent and off-axis beams. Three three-focal-spot diffractive lenses have been designed, optimized and manufactured to verify the influence of parameters such as focal length, focal position shift, deflection angle or radiation frequency on the proper detection and separation of focal spots using different receivers. The reliable characterization of multi-focal-point structures can be performed only with high-acceptance-angle detectors, such as, for example, field-effect transistors equipped with a patch antenna. On the other hand, for the detection of a single demultiplexed signal, a much more directive receiver can be applied, as long as it is placed at a proper angle.  
Keywords:THz; telecommunication; multiplexing; THz detectors; diffractive optical elements; 3D printing; MIMO systems +
Footnote †: journal: Applied sciences
# A Compact Multi-Identity Fully Homomorphic Encryption Scheme Without Fresh Ciphertexts
## 5 Multi-Identity Full Homomorphic Encryption Scheme
### Efficiency Analysis of Ours MIBFHE Scheme  
We compare the existing MIBFHE schemes with the WZ-MIBFHE scheme, focusing on two main aspects: scheme attributes and scheme parameters. The results are shown in Tables 3 and 4.  
According to Equation (3), the overall error of the scheme after \(L\) homomorphic operations for \(D\) identities is  
\[\left\|\widetilde{\theta}_{eval}\right\|\leq D^{2^{L}}\big{(}B_{\chi}\cdot \omega\cdot m^{\prime}-p\big{)}\]  
Since the number of user participation \(D\) is known, according to this formula we need to choose the parameters rigorously to ensure the decryption correctness of the scheme. Based on Tables 3 and 4, The IBE architecture of WZ-MIBFHE and the IBE architecture from [22] are both based on ABB10; therefore, our public and private key structures are similar, and their sizes appear to be the same. However, WZ-MIBFHE has a lower dimension, resulting in smaller public and private key sizes as well as ciphertext sizes, significantly enhancing the compactness of the scheme. WZ-MIBFHE employs the decomposition method for ciphertext expansion, allowing users to generate expandable ciphertexts directly from the encryption algorithm without needing to generate fresh ciphertexts in advance. This approach reduces the overall operations required, making the scheme more concise. Additionally, with the increase in the number of users participating in WZ-MIBFHE compared to similar schemes, our noise expansion rate is significantly lower, indicating that we can perform more homomorphic evaluations. Compared to [20], WZ-MIBFHE has better performance and parameters, but does not implement the multi-hop property.
# SENTINEL: A Secure and Efficient Authentication Framework for Unmanned Aerial Vehicles
## 6 Digital Certificate for SENTINEL  
Public key infrastructure (PKI) is widely used to verify users and devices by using digital certificates on public communication channels such as the Internet. The X.509 v3 certificates [14] are most popularly used as the de facto standard to build PKI-based systems. However, the conventional X.509 v3 certificates may be too heavy in resource-constrained drones with respect to communication overhead, power consumption, and memory footprint because they are originally designed to accommodate comprehensive specifications of digital certificates with various options and extensibility. Thus we develop a lightweight certificate format that is viable for drones.  
Figure 7 shows our lightweight certificate format for SENTINEL. Compared to the conventional X.509 v3 certificates, the proposed certificate only contains minimal information required to build the PKI in IoD environments. To further reduce the size of the certificate, we also use a binary format in the proposed certificate, instead of a human-readable text format adopted in the X.509 v3 certificates. The followings are the descriptions of each field in the proposed certificate.  
* **Version.** This field represents a version of the certificate, which may be changed when the certificate is updated. We set the size of this field to 1 byte.
* **Issuer's (CA) Distinguished Name.** This field specifies the issuer's distinguished name. The size of this field is 2 bytes.
* **Validity Period.** This field specifies the period for which the certificate is valid. This certificate can no longer be used after being expired. We set the size of this field to 16 bytes.
* **Subject's Distinguished Name.** This field specifies the distinguished name of the subject, such as a drone's identifier and a ground station's identifier. The size of this field is 4 bytes.
* **Subject's Public key.** This field contains the subject's public key, and the length of the public key can be approximately 91 bytes. Unlike conventional X.509 v3 certificates, this field does not specify the type of a public key algorithm compatible with the public key because we assume a fixed algorithm. For drones, we recommend using ECDSA [28] to reduce their computational overhead.
* **Issuer's Signature.** This field contains the issuer's signature on this certificate, which will be used by recipients to verify the validity of this certificate. The size of this field is approximately 70 bytes.  
In this paper, we define the size of each field for our prototype implementation. However, it can be flexibly adjusted depending on the requirements in PKI applications. Our experiment results in Section 7.2 show that the size of the proposed certificate was about 3.7 times smaller than the size of a typical X.509 v3 certificate.
# The Internet of Drones: Requirements, Taxonomy, Recent Advances, and Challenges of Research Trends
## 3 Requirements of Internet of Drones (IoD)
### Communication Requirements
#### 3.1.4 Drone Identification and Regulation  
Mobile networks may help identify and control drones by supporting drone registration, tracking, provision, and coordination [19; 20].  
* Registration: Identifying but standardizing the drone equipment number, serial number, and flight control serial number helps track the whole process orderly from initial drone production to in-use. Through standardizing registration of drone users, owners and mobile networks, drone users and owners can be legally monitored.
* Monitoring: Drone connections and data communications can be detected and monitored through mobile networks. Drone implementations can be completely tracked in real-time with additional regulatory protocols.
* Forecast: Flight situations can be dynamically evaluated and early warning of possible risks can be achieved by tracking drone positions and monitoring the flight traffic and path.
* Coordination: Knowledge exchange between industries and different companies can be carried out by approved oversight of all vertical industries involved.
# Assessing the Performance of Different Grains in Gluten-Free Bread Applications
## 1 Introduction  
Coeliac disease is a lifelong autoimmune enteropathy induced by gluten consumption, affecting persons which are genetically susceptible. Due to the increasing prevalence worldwide, the coeliac disease started to be considered a major public health problem [1]. Taking into account that no efficient cure was reported yet for this condition, avoidance of gluten-containing products in the diet was recommend as the main solution. Therefore, identifying ingredients and tools for obtaining high-quality gluten-free products is highly desired. Rice flour is considered the most important ingredient in gluten-free bread making, but in the last period the minor grains like millet, sorghum and quinoa became increasingly important for producing gluten-free baking products [2].  
Originating from South America but with a great adaptability to different growing conditions, quinoa has become more and more popular due to the well-balanced nutritional composition [3; 4; 5]. Quinoa is recommended primarily by the content and quality of its proteins, being rich in amino acids which are deficient in cereals. In fact, the amino acids composition of quinoa proteins is close to the ideal protein recommended by FAO [3; 6; 7; 8]. In addition, quinoa contains high levels of unsaturated fatty acids [9; 10; 11], vitamins [9], minerals [12], dietary fiber and polyphenols [13].  
Sorghum and millet are two cereals which are insufficiently used in bakery products, even if they have nutritional compositions comparable to other cereals [14], and could be used if not as the based flour, at least as functional ingredients, mainly due to phenolic compounds [2; 15; 16] and resistant starch contents [14; 17]. Moreover, the two cereals can be grown on semi-arid regions, where other cereals do not give consistent productions.  
Several studies pointed out that quinoa, sorghum and millet have huge potential to be used for developing functional foods, due to the high level of phenolic compounds, antioxidant capacity and low starch digestibility [2; 3; 17].  
The objective of this study was to compare quinoa, sorghum, millet and rice in terms of composition, bread-making potential and physical properties, resistant starch, antioxidant activity and total phenolic content of breads. The rice was included in this study due the large applications in gluten-free bread making.