esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Current Status of Development of Geophysical Exploration Techniques
### Exploration Techniques Based on Elastic Wave Velocity
#### 2.2.3 Land Sonar Method  
The land sonar method is a land minimum offset (seismic offset) ultra-wideband elastic wave reflection continuous-section method. It applies the principle of the elastic wave reflection method, and it absorbs the seismic reflection method, hydroacoustic exploration method, ground-penetrating radar, acoustic method, computational mathematics, and vibration measurement technology. Its acquisition system has the characteristics of ultra-short aftershocks. It can achieve ultra-wideband excitation and reception (bandwidth up to 2000-3000 Hz) and a minimum seismic-detection distance close to zero. The land sonar method determines each reflection interface based on the characteristics of the reflected-wave image curve in the profile and calculates the depth of the reflection surface in terms of the reflected wave time and elastic wave velocity in each medium. The waveform is displayed with a variable area color in the actual profile, making it clear and intuitive to identify phase changes.  
[PERSON] et al. [39] developed a method for hidden dangers in highway bedrocks, and the results matched with the borehole data, proving that the method can avoid many interference waves compared with conventional geophysical exploration methods, with characteristics such as high resolution, very small offset distance, and high reflected wave energy. [PERSON] et al. [40] used the terrestrial sonar method to detect and analyze faults in projects along a diversion tunnel, and the results showed that the method can accurately detect faults, fracture zones, and caves. [PERSON] et al. [41] used a combination of terrestrial sonar method and differential electric bathymetry to geologically probe a reservoir area, and the method showed good work adaptability and high resolution, making it ideal for shallow fine exploration. However, the land sonar method increases the workload of field excitation. The work efficiency is lower than that of the conventional seismic reflection method, and the data processing technique involving multiple coverage cannot be used.
# Research Progress on Carrier-Free Phase-Retrieval Receivers
## 2 Principle of CF-PR Receivers
When polarization multiplexing is applied to double the transmission capacity and SE, it is also challenging to recover the polarization multiplexed QAM signals for the CF-PR receiver.
# Energy Efficiency of a Decode-and-Forward Multiple-Relay Network with Rate Adaptive LDPC Codes +
## 2 System Model
### Data Encoding and Decoding Using LDPC Codes
The reason for this gain is that with an increasing number of copies, the probability that all of them fade simultaneously decreases and hence, the chances of reception increase [9].
# Speckle Noise Detection and Removal for Laser Speech Measurement Systems
## 4 Experiments and Discussion
### Evaluation Indexes  
As it is difficult to count the number of points related to speckle noise in real-world detected speech, we first compared and evaluated the different methods by visually inspecting the resulting waveforms. Afterwards, as the accuracy of noise localization can also be indirectly judged by looking at the signal quality, we used the SNR [31] and PESQ [32] as objective metrics.  
The SNR and PESQ indicators are calculated by comparing the examples where the speckle noise is removed, and the pure speech. To ensure the experimental results are accurate and to minimize the number of errors, all of the metrics are averaged across each group of 50 speech signals.  
Figure 8: Real-world experiment: (**a**) The laser speech measurement system; (**b**) The loudspeaker, paper cup and acoustic level meter.
## 2 Background and the Related Work
### Related Works
#### 2.2.1 Encryption and Network Security in SDN  
[PERSON] and [PERSON] (2018) examined the alleged impact of transport layer security (TLS) encryption on OpenFlow performance over SDN. In their research, they pointed out the trade-offs between security and performance vis-a-vis TLS adoption and elaborated on its consequences on the packet-in delays across multiple SDN switch models.  
[PERSON] et al. (2018) presented a new scheme separating multicast control from data transmission to provide higher capacity and robustness for multicast applications over SDN. This scheme used conventional cryptography and not one based on homomorphism, which improved efficiency and reduced the complexity of computations.  
In order to secure an SDN system, [PERSON] and [PERSON] (2018) implemented hybrid encryption algorithms, which combined AES, RSA, and hybrid approaches, offering greater security and efficiency than RSA alone.  
[PERSON] and [PERSON] (2018) proposed an identity-based encryption method for source routing systems enabled by SDN. The authors claimed to improve the security and path verification while keeping the size of the authenticator fixed and supported multiple recipients and parallel links.  
[PERSON] et al. (2018) presented a review regarding traditional, AI-based, and moving target defense security methods for addressing challenges and improving security over SDN. The abovementioned studies represent meaningful progress in SDN security. However, they lack insight into how resilient their methods will be against a comparatively wide variety of attacks that involve using cryptanalysis to extract information from the underlying cryptographic structure.
# Security Framework for IoT Based Real-Time Health Applications
###### Abstract  
The amazing fusion of the internet of things (IoT) into traditional health monitoring systems has produced remarkable advances in the field of e-health. Different wireless body area network devices and sensors are providing real-time health monitoring services. As the number of IoT devices is rapidly booming, technological and security challenges are also rising day by day. The data generated from sensor-based devices need confidentiality, integrity, authenticity, and end-to-end security for safe communication over the public network. IoT-based health monitoring systems work in a layered manner, comprising a perception layer, a network layer, and an application layer. Each layer has some security, and privacy concerns that need to be addressed accordingly. A lot of research has been conducted to resolve these security issues in different domains of IoT. Several frameworks for the security of IoT-based e-health systems have also been developed. This paper introduces a security framework for real-time health monitoring systems to ensure data confidentiality, integrity, and authenticity by using two common IoT protocols, namely constrained application protocol (CoAP) and message query telemetry transports (MQTT). This security framework aims to defend sensor data against the security loopholes while it is continuously transmitting over the layers and uses hypertext transfer protocols (HTTPs) for this purpose. As a result, it shields from the breach with a very low ratio of risk. The methodology of this paper focuses on how the security framework of IoT-based real-time health systems is protected under the tiers of CoAP and HTTPs. CoAP works alongside HTTPs and is responsible for providing end-to-end security solutions.  
e-health; IoT and data privacy; IoT layered architecture; CoAP +
Footnote †: journal: Accepted: 13 March 2021
# Influence of the Radial Gap on the External Gear Pump Performance
## 4 CFD Results and Verification  
Eight rotational frequency modes were simulated--500, 750, 1000, 1250, 1450, 2000, 2500, and 3500 RPM at two radial gap values: 0.02 mm and 0.04 mm. The modes were selected due to the documentation available from the pump manufacturer [54], where the flow rate is given in the form of a curve in the range of 500-3500 RPM, and at a rotational frequency equal to 1000 and 1450 RPM, the flow rate values are given in a table form.  
A gap of 0.02 mm was considered nominal, while the value of 0.04 mm was predicted to be close to the maximum at which the pump maintains its normal performance. Additionally, for a rotational frequency of 1000 RPM, numerical experiments were made at values of the radial gap of 0.03 mm and 0.05 mm, in order to fully investigate the influence of this parameter on the pump flow rate. Thus, the total number of realized simulations is 18.  
The operating pressure in all the simulated modes is \(p_{out}\) = 10.5 MPa. This value was also chosen because of the technical documentation, which provides experimental data for it that can be used to verify the model.  
The workability of the developed CFD model is confirmed by the following Figure 5, which shows the velocity and pressure distribution at the chosen operating pressure of 10.5 MPa and a rotational frequency of 1450 RPM.
# Interpolation-Filtering Method for Image Improvement in Digital Holography
## 2 Image Quality Enhancements in Digital Holography
### Noise Reduction Methods in Digital Holography
#### 2.3.2 Optical Methods  
The main group of optical solutions for speckle noise control usually involve the registration of a large number of images with different speckle structure distributions. There are different approaches for the registration of a large number of holograms. A common method is to use a diffuse scatterer or similar elements [28; 29; 30]. In more complex schemes, different angular distortions [35], shifts [36], polarizations [34], and wavelengths [33] are used to create different speckle distributions on the registered hologram. A large number of holograms with different speckle distributions are registered. The images from them are reconstructed. Most often, they are further averaged into one image. By applying such a simple process, the influence of speckle noise is significantly reduced.  
In hybrid methods, which combine optical and digital approaches, a set of holograms [29; 30; 34; 35; 36] is also first registered. The reconstructions are averaged into a single image. Averaging over the same pixel [29; 34; 35; 36] and over the pixel neighborhood [30] can be used. For example, Ref. [35] averages 100 images reconstructed from holograms recorded at different angles with the additional use of a diffuse scatterer. A digital filter is applied to the obtained image, resulting in a higher-quality reconstructed hologram.  
A negative factor in the implementation of optical solutions or optical part of methods is the necessity to register ten [30] or even a hundred [35; 36] holograms. Often, the number of configurations for creating uncorrelated speckle distributions is limited. In this case, the absence of correlations between speckle distributions allows us to obtain the best result [35]. With the appearance of correlations between speckle distributions on holograms, the efficiency of averaging decreases.
# Chitosan Nanocomposite Coatings for Food, Paints, and Water Treatment Applications
## 3 Chitosan-Based Nanocomposites
### Chitosan-Metal/Metal Oxide  
Noble metal, such as silver, are very effective antimicrobial agents [77; 78; 79] and can be synthesized in situ in a chitosan matrix due to the metal ion chelation capability of chitosan. Taking into account that silver nanoparticles are well-known for their antimicrobial property, chitosan-silver nanocomposite coatings materials have been studied on metal, glass, wood, etc., surfaces [80; 81; 82]. Metal oxide nanomaterials are commonly applied in polymer matrix as filler materials to enhance the antimicrobial and mechanical properties of the films and coatings, which are mainly used for food packaging and food preservation applications [83; 84; 85; 86]. Silica nanoparticles in chitosan were reported to selectively absorb rare earth elements [87], while zinc oxide nanoparticles were reported to photo-catalytically generate reactive oxygen species (ROS), leading to high anti-diatom and anti-bacterial activities under sunlight [85; 86].
# Hybrid Wind-Redox Flow Battery System for Decarbonizing Off-Grid Mining Operations
## 3 Methodology
### Sizing of the Energy System
#### 3.3.1. Sizing, Installation, and Cost of the Wind Farm
It consists of two main components: capital expenditure (CAPEX), which represents upfront investment costs, and operating expenditure (OPEX), which includes maintenance and operational expenses. LCOE is typically expressed in CAD/kWh or CAD/MWh and is influenced by five primary factors: initial capital investment, ongoing operational costs, system performance, financial and tax assumptions, and project lifespan. The study also incorporates data from the IRENA report [46], which provides relevant insights specific to Canada, including the Ragland mining site. Based on these indicators and the referenced report, the cost analysis yielded the results in Table 4.  
The results indicate a substantial increase in both OPEX (150.8%) and CAPEX (164.9%) for the Ragland site compared to the national average, primarily due to the site's extreme environmental conditions, including harsh winters and remote location. The price of an ENERCON E-115 EP3 E4 wind turbine (4.260 MW) for the Ragland site is calculated at approximately CAD 20,690,000 using the cost estimates from Table 4. A simplifying assumption was adopted to determine the total wind farm investment cost, wherein the cost of a single wind turbine is multiplied by the total number of turbines planned for deployment.
## 4 Digitalization of MGs
### Augmented Reality
AR technology relies on data and connectivity to operate effectively. As such, there may be concerns about data security and privacy when using AR technology in a microgrid system. Moreover, AR technology relies on hardware, and the limitations of that hardware can impact its effectiveness. For example, low-quality cameras may not capture the real-world environment effectively, resulting in inaccurate overlays. As AR technology continues to develop, there are several directions in which it could be applied in MGs. Some potential future direction examples for AR in MGs can be given. For instance, integrating AR technology with AI could enhance its capabilities significantly [192]. By using AI algorithms to analyze data from the microgrid, AR could provide real-time insights and recommendations for optimizing the microgrid's performance. In addition, wearable AR devices, such as smart glasses or head-mounted displays, could enhance the use of AR technology in MGs. These devices provide a more hands-free and immersive experience, allowing operators and technicians to interact with the digital overlay more effectively [190; 193; 194]. Another expected example is that the AR technology could be used to facilitate energy trading in MGs. By overlaying real-time information about energy supply and demand, AR could help microgrid operators make more informed decisions about energy trading, leading to improved efficiency and cost savings. Moreover, AR technology could also be used to engage consumers in microgrid systems. By overlaying digital information on top of real-world energy usage, consumers could gain a better understanding of their energy usage and how it impacts the microgrid system as a whole. While there are challenges and limitations to its use, ongoing developments in AR technology could help overcome these barriers. As AR technology continues to evolve, its applications in MGs could expand, providing a range of benefits for operators, technicians, and consumers alike.
# Several Tree-Based Solutions for Predicting Flyrock Distance Due to Mine Blasting
## 3 Case Study  
### Mine Description  
One of the largest porphyry copper mines in Iran is the Sungun Copper Mine, which is located in the northwest, about 125 km northeast of Tabriz, in East Azarbaijan province. The exact location of this mine is shown in Figure 5, which is at 46\({}^{\prime}\)43\({}^{\circ}\) E longitude and 38\({}^{\prime}\) 42\({}^{\circ}\) N latitude. The mine's location is 2000 m above sea level.  
The main geological event in this area is a hydrothermal intrusion, and the mineralization of Sungun Copper Mine refers to the Cenozoic Sahand-Bazman orogenic belt hosted by altered quartz-monzononite rocks. Chalcopyrite, pyrite, chalcocite, cuprite, and malachite are the primary minerals that make copper the main product of the Sungun Copper Mine. In addition, the grade trend in this deposit has a direct increasing relationship with depth, especially in the hypo-gene zone. Additionally, gold, silver, and molybdenum are all extractible from this mine. The geological and geometrical features of this mine are indicated in Table 2.  
In the Sungun Copper Mine, the extraction process uses bench blasting with one free face. ANFO was used as the main explosive material in blastholes, and drill-cutting particles were used for stemming holes. The initial system of blasting operations was the detonating cord. The main blasting pattern was triangular (staggered), and the ratio of burden to spacing depended on the properties of the blasting block in diverse parts of the mine. The blasting sequence is a flat face method, in which, in this sequence pattern, zero considers as an inter-hole delay time, and a delay event occurs between blasting rows [87]. One of the most undesirable results of the blasting operations in this mine is flyrock. Therefore, this study was planned to be investigated to develop a model for estimating flyrock distance.
# Efficient Expiration Date Recognition in Food Packages for Mobile Applications
## 3 Datasets and Implementation Details
### Model Training  
The proposed models are trained with the PyTorch CUDA 11.8 framework. They are trained on a single NVIDIA GeForce GTX 1080 GPU with 8 GB of memory. Table 2 shows the parameters of the detection model and the recognition model, respectively.  
**Detection Model**: AdamW optimizer is chosen because it can achieve faster convergence compared to the standard Adam optimizer by decoupling weight decay from the gradient update and making it more resilient to variations in the training data. The input size is 800 in width and 1280 in height, and the initial learning rate is 0.001 with warm-up changes. The batch size is 6 per GPU and a total of 20 training epochs. Data augmentation is applied to make more training samples; the augmentation techniques include scale, stretch, translate, random rotation no more than 5\({}^{\circ}\), random brightness, random saturation, random contrast, and normalized with mean [103.53, 116.28, 123.675] and variance [0.017429, 0.017507, 0.017125] in BGR order.  
\begin{table}
\begin{tabular}{c c c} \hline
**Number** & **Date Format** & **Sample** \\ \hline
1. & Y,m,d & 2024,02,13 \\
2. & d,m,Y & 13,02,2024 \\
3. & m,d,Y & 02,13,2024 \\
4. & b,d,Y & FEB,13,2024 \\
5. & d,b,Y & 13,FEB,2024 \\
6, & Y,b,d & 2024,FEB,13 \\
7. & m,Y & 02,2024 \\
8. & Y,m & 2024,02 \\
9. & b,Y & FEB,2024 \\
10. & Y,b & 2024,FEB \\
11. & y,m,d & 24,02,13 \\
12. & d,m,y & 13,02,24 \\
13. & d,b,y & 13,FEB,24 \\
14. & b,d,y & FEB,13,24 \\
15. & y,b,d & 24,FEB,13 \\
16. & m,d & 02,13 \\
17. & d,m & 13,02 \\ \hline \end{tabular}
\end{table}
Table 1: Different date formats supported to parse.  
\begin{table}
\begin{tabular}{c c c} \hline
**Model** & **Detector** & **Recognizer** \\ \hline input size & [800,1280] & [32,128] \\ optimizer & AdamW & Adam \\ learning rate & 0.001 & 0.0007 \\ batch size & 6 & 384 \\ epoch & 20 & 20 \\ \hline \end{tabular}
\end{table}
Table 2: The parameters of the detector and recognizer, respectively.  
**Recognition Model**: the optimizer is Adam; the input size is resized to 32 width and 128 height. The initial learning rate is \(7\times 10^{-4}\); the batch size per GPU is 384 with a total of 20 training epochs. The data augmentation used includes Gaussian blur, motion blur, random rotation no more than 30\({}^{\circ}\), shear, translate, and normalized with mean [127.5, 127.5, 127.5] and variance [1/127.5, 1/127.5, 1/127.5, 1/127.5] in RGB order.
# Impact of Ar/CF4 Mixed Gas Flow Rate on Silicon Etching Using Surface Discharge Plasma
## 3 Experimental Results
In Figure 6, the relationship between the depth and width of grooves formed on the silicon substrate surface through surface discharge plasma etching at various argon (Ar) and carbon tetrafluoride (CF4) gas flow rates, dependent on the discharge-sustaining voltage, is depicted. The etching duration for the silicon substrate was held constant at 5 min. Due to the complexity of comparing etching depth and width at each flow rate using a three-dimensional image captured by laser microscopy, the average etching depth and width derived from these images were used for the analysis. The analysis in Figure 6 reveals that grooves created by surface discharge plasma expand in both depth and width as the flow rate of the Ar and CF4 mixed gas increases. This expansion is attributed to the increased presence of Ar ions and active species in the plasma, which is facilitated by an elevation in the discharge-sustaining voltage. Furthermore, a higher discharge-sustaining voltage leads to more pronounced etching in both the depth and width directions. This increase is due to the higher abundance of active species that promote etching and diffuse more broadly in the width direction as the discharge-sustaining voltage increases. Figure 7 illustrates the changes in groove depth and width through surface discharge plasma etching at different Ar and CF4 gas flow rates, as a function of etching time. The data indicate that silicon etching advances in both depth and width with increasing flow  
Figure 5: Methodology for evaluating grooves formed on a silicon substrate through etching with surface discharge plasma. Figure 6: Dependence of (**a**) etched depth and (**b**) etched width on the silicon substrate surface by surface discharge plasma at various Ar/CF4 gas flow rates relative to the discharge-sustaining voltage. rates of the Ar/CF4 mixed gas. Moreover, prolonging the etching treatment duration leads to further development of silicon etching in both depth and width directions. The surface discharge plasma exhibits a columnar shape with a diameter of approximately 200 \(\upmu\)m, and the dielectric is formed by a rectangular dielectric electrode. Hence, etching in the width direction occurs through the diffusion of active radical species, such as Fx and CFn, resulting in a gradual deceleration of etching progression in the width direction beyond the surface discharge plasma region.