esa-sceva/satcom-chunk-collection huggingface dataset:
# UAV Detection Using Thrust Engine Electromagnetic Spectra
### Methods for UAV Detection  
The number of approaches to the problem of UAV detection is increasing. Precision, range, operating circumstances, and a host of other factors vary between each method. The most advanced and rapidly evolving techniques for UAV detection are as follows:  
* **Examination of the acoustic signal footprint**. An acoustic signal from the UAV's thrust motors is picked up by a microphone or microphone array that is analyzed and compared to the known UAV's signal pattern in real time. The UAV is discovered if the signal patterns match [13].  
* **Analyzing the optical footprint.** An individual video camera or a camera array is used to record the scene around it. The image data is processed in real-time for the recognition of the signature of the flight-path [14].
* **Examination of heat signatures.** The image of the surroundings is captured using a thermal camera or camera array. The image data is processed in real-time for the recognition of the signature of the flight-path [15].
* **Analysis of a radar signature.** The presence of a UAV's radar signature, which is created when the UAV's body interacts with RF pulses that were emitted by the detecting element. Real-time processing of the UAV's reflected signal for flight path detection. Recently, a concept of a built-in radar in the UAV's structure was proposed [16].
* **Radio transmission.** Real-time reception and analysis of the radio frequency spectrum are performed for modulation, video, telemetry, and control data decoding. Decoding of the well-known communication data packets yields useful information [17].
* **Combined techniques.** Any combination of multiple detection techniques is used for UAV detection in order to improve precision, reliability, stability, location, and range [18].
# A Printed Wearable Dual-Band Antenna for Wireless Power Transfer
## 4 Conclusions  
It is important to study flexible small antennas for the use of microwave power transfer (MPT) in wearable applications. In this work, we proposed a dual-band antenna operating at ultra-high frequency antenna (2.5 GHz/4.5 GHz) for MPT applications. The antennas were based on split ring resonator. The shape of the antenna provides multiple dimensions that can be optimized for the desired frequency. We proposed a small antenna with the area of 14 mm \(\times\) 15 mm. The proposed design can be modified for other frequency bands. The proposed antenna provides near omni-directional radiation pattern that is desirable for wearable WPT. The transmission efficiency does not vary significantly due to change of distance. The SAR values were also examined. In future, the effect of bending and crumpling on the power efficiency will be investigated. The design will be optimized for various bending conditions.  
Conceptualization, M.H. and S.N.; methodology, M.H. and S.N.; software simulation, M.H.; validation, M.H., and S.N.; formal analysis, M.H.; investigation, M.H., and S.N.; resources, S.N.; writing--original draft preparation, M.H.; writing--review and editing, S.N.; supervision, S.N.; project administration, S.N.; funding acquisition, S.N.  
North Dakota Department of Commerce, Venture Phase I, DoC #16-02-J1-112.  
The financial support from North Dakota Department of Commerce through a Venture Phase I grant is appreciated. The financial support of the School of Electrical Engineering and Computer Science is acknowledged.  
The authors declare no conflict of interest.  
Figure 8: SAR distributions in Phantom (W/kg) (**a**) at 2.5 GHz, and (**b**) at 4.5 GHz.  
Figure 7: Simulated and measured transmission coefficient (\(S_{21}\)) versus distance between the transmitter (TX) and receiver (RX) antennas (**a**) at 2.5 GHz, (**b**) at 4.5 GHz.
# Dielectric Characterization of Chinese Standard Concrete for Compressive Strength Evaluation
## 3 Experimental Results  
In this section, measurement results of the compressive strength and dielectric constants of GB concrete after 28 days of curing, will be presented and discussed. The real part of the complex relative permittivity, or the dielectric constant of each type of GB concrete, will be modelled by the Jonscher model. The aim of this study is to obtain the value at any frequency from 100 MHz, up to a very high frequency (e.g., 10 GHz). Further, the correlation between the compressive strength and dielectric constant of each GB concrete can be determined at any frequency up to 10 GHz.
## 3 Results and Discussion
### S-Parameters  
For the purpose of comparison, the simulated results with the measured ones, the S-parameters for left-sided ports (Port 1 to 5), \(S_{11},S_{22},S_{33},S_{44}\), and \(S_{55}\) have been depicted in Figure 7a,b, and for right-sided ports (Port 6 to 10), \(S_{66},S_{77},S_{88},S_{99},S_{1010}\), are shown in  
Figure 5: The variations of the ground slot to achieve the desired frequency band in terms of \(S_{1,1}\). (**a**) Reflection coefficient by varying ground cut width (gcl). (**b**) Reflection coefficient by changing ground cut length (gcw).  
Figure 6: S-parameters improved by incorporating decoupling structure.  
Figure 7c and Figure 7d, respectively. The plots indicate a discrepancy of about 150 MHz for almost all measured values from their corresponding simulated counterparts, primarily due to SMA connector soldering as well as mild fabrication and measurement errors. Nevertheless, the simulated reflection coefficient continued to increase beyond unity, and the measured reflection coefficient also increased, with both operating within the upper mid-band frequency range. Additionally, the above proposed antenna was modeled for the presence of hand and head models, and the reflection coefficients are reported in Figure 7e,f. In both cases, the reflection coefficient values were still rising slightly across the desired frequency range.  
Figure 7: Reflection coefficient of proposed ten-port MIMO antenna array. (**a**) Simulated reflection coefficient (left side). (**b**) Measured reflection coefficient (left side). (**c**) Simulated reflection coefficient (right side). (**d**) Measured reflection coefficient (right side). (**e**) Reflection coefficient with hand. (**f**) Reflection coefficient with head.  
The simulated and measured transmission curves with respect to isolation also presented performance of the antenna that all the values of \(S_{12},S_{13},S_{14},S_{15},S_{16}\), and \(S_{23}\) were below \(-10\) dB at the entire operating bandwidth, as shown in Figure 8a,b. Specifically, a low \(S_{12}\) value shows that the isolation between the antenna ports is very good if it is below \(-10\) dB (VSWR 3:1), which is a requirement for highest MIMO performance. These results provide practical evidence regarding the feasibility of the fabrication and measurement procedures, demonstrating that the given antenna provides high performance and excellent isolation. These results also confirm high suitability of the proposed configuration for achieving the required frequency in modern 5G NR applications.
# An Overview of Cube-Satellite Propulsion Technologies and Trends
## 7 Hall Effect Propulsion/Hall Thrusters  
### Operating Principle  
Hall Thrusters are electrostatic devices [63] that generate thrust by first ionizing and then accelerating the propellant in mutually perpendicular electric and magnetic fields. These thrusters work on the principle of the well known Hall Effect that states the following: when electric current is applied to a conductive material (propellant) placed in mutually perpendicular electric and magnetic fields, a potential difference is developed that is perpendicular to the applied electric and magnetic fields [74]. The schematic of a Hall thruster is shown in Figure 6 that includes propellant storage, discharge channel, external cathode, anodes and the magnetic field generator. The applied magnetic field is radial, while the accelerating electric field (acting from anode towards cathode) is axial [63]. Note that Hall thrusters, unlike gridded ion thrusters, do not have the grid system (series of grids), instead the grids are replaced with a strong magnetic field perpendicular to the flow of ions. This magnetic field reduces the mobility of electrons coming from the external cathode, thereby restraining their flow towards anode in the accelerating electric field [63; 75; 76]. Hall thrusters have many advantageous features like high specific impulse (higher than most systems except ion engines), higher thrust density [77] and simplicity in design (when compared to gridded ion engines due to lack of accelerator grids) [78]. However, they also face some challenges with erosion of magnetic circuitry due to discharge plasma and lower efficiency (6-30% at 0.1-0.2 kW and 50% at 1 kW) [79].  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Company/Institution with Location** & **Engine** & **Thrust (mN)** & **L\({}_{\text{pr}}\) (s)** & **Power (W)** & **Propellant** & **Remarks** & **Ref.** \\ \hline Bussek, Natick, MA, USA & BIT-1 & 0.1-0.18 & 2150-3200 & 28 & Xe, Iodine & - & [9; 71] \\ Bussek, Natick, MA, USA & BIT-3 & 1.15 & 2500 & 75 & Iodine & will fly on Lunar IceCube (6U) & [71; 72] \\ Airbus, Lampodkshausen, Germany & BIT-\(\
u\)X & 0.05-0.5 & 300-3000 & \(<\)50 & Xe & - & [73] \\ Airbus, Lampodkshausen, Germany & RTT 10 EVO & 5, 15, 25 & \(>\)1900, \(>\)3000, \(>\)3200 & 145 & Xe & available in 3 designs & [73] \\ \hline \hline \end{tabular}
\end{table}
Table 5: Summary of RF Ion Propulsion Systems.  
The performance factors for Hall thrusters like ion exit velocity (shown in Equation (12)), thrust (shown in Equation (13) ) and specific impulse (shown in Equation (14)) are the same as the ones for RITs [63].
## 2 Related Work  
In 1981, [PERSON] and [PERSON] proposed a network algorithm where they considered that the nodes are created different clusters and each cluster has head node (one of the cluster nodes) and remaining are member nodes. Head node has possibility to exhaust battery power quickly. Therefore, dynamically changing the head nodes may be implemented using rounds [18]. In 2002, [PERSON] et al. has proposed to improve LEACH algorithm based on principle election of cluster head [19]. In 2004, [PERSON] and [PERSON] [20] developed 'Hybrid Energy-Efficient Distributed' algorithm based on basis of the residual energy of cluster head nodes. In 2006, [PERSON] and [PERSON] [21] focuses on mobile nodes. In 2013 [PERSON] and [PERSON] proposed a TOPSIS technique [22] focused on 'Multiple Attribute Decision Making' approach of cluster leaders' election. In 2016, [PERSON] et al. [20], proposed and energy efficient fuzzy technique for CH selection in WSN. The main aim of the work was to reduce the energy consumption and increased the network life span using fuzzy parameter. In 2017, [PERSON] et al. proposed fuzzy-TOPSIS based election of cluster head in mobile network using four criteria and compared with the traditional LEACH and Fuzzy [23]. In 2018, [PERSON] et al. [24; 25], proposed the clustering algorithm on the basis of K-means and PROMETHE methods. In 2019 [PERSON] et al. focused on a CH selection and dynamic distributed clustering method. The authors considered the protocol and the clustering algorithm [LTE-M] [26]. In 2019, [PERSON] et al. focused on CH selection using AHP method [27; 28]. In 2020, [PERSON] et al., proposed a modified Belief function base on inter-criteria analysis using MCDM method [29]. In 2021, [PERSON] proposed supply chain model using MCDM method [30]. In this paper, big data was used as a platform for finding the role of green supply chain model (GSCM) over the supply chain finance and the fuzzy ANP technique is used as MCDM method. In 2021, [PERSON] and [PERSON] surveyed different CH selection method in WSN. They surveyed different algorithm like probabilistic, fuzzy logic, adaptive, and multi-attribute decision making techniques and discussed different challenges in network [31].  
From the related work, we concluded that CH selection depends upon several criteria and the fuzzy MCDM method was used to calculate the rank from the several criteria. In this paper, we attempt to provide a framework for CH selection in remote SC environment by which is important for head node selection due to existence of several clusters and nodes position. Therefore, the main aim of this research is to build criteria from the node position for CH selection in SC environment and to calculate weight for CH selection considering their importance level. The entire process will be discussed in the next section.
# A Review-Unguided Optical Communications: Developments, Technology Evolution, and Challenges
## 4 Underwater Optical Communication  
Due to several attractive features of UOC, it also successfully penetrated to underwater applications as well. Nowadays, it is being used for underwater communication, underwater scanning, underwater vehicle/weapon tracking/guidance, deep-sea mining, underwater seabed monitoring, sea-floor mapping, aerial-platform-underwater scanning/communication, etc. The developments in OWC are broadly classified into two categories, namely (i) underwater optical wireless communication (UOWC) and (ii) photoacoustic communication (PAC), which are reviewed below.
# Evaluation of _Jatropha curcas_ and Pistachio Shell Particles as Modifier for Asphalt Binder
## 3 Results and Discussion
### Rheology
The improvement in rutting resistance within high temperatures when particles modifiers were added can be attributed to its reinforcing factor, which enhanced the bond strength between asphalt binder particles due to its high surface area [1]. The tan \(\delta\) measurement expresses the ratio of the viscous to the elastic modulus and is useful for detecting the physical changes experienced within a temperature range. Figure 5 shows the isochronal curves of tan \(\delta\) for the samples of asphalt modified with _Jatropha_ particles. These curves were constructed at the same angular frequency as the experiments presented in Figures 3 and 4. The elastic response of the _Jatropha_-modified samples is better than that of the unmodified asphalt since all the curves lie below the reference asphalt curve. The increasing tendency of tan \(\delta\), particularly at high temperatures, reflects that the elastic behavior of the asphalt decreases as the temperature increases, which implies that the phase angle \(\delta\) takes values closer to 90\({}^{\circ}\). The mechanical implication of this fact is that the asphalt is suffering a transition from a solid like behavior to a predominantly Newtonian-viscous nature. Figure 5 shows that the lowest tan \(\delta\) values correspond to the J2 sample; although the J2 curve increases at every point with the other curves; its slope is the least steep and increases smoothly even in the high-temperature region, where the tan \(\delta\) of the other samples, especially that of the unmodified asphalt, steps up abruptly. As a result, the best elastic response before flowing at high temperatures corresponds to the 2 wt.% _Jatropha_-modified asphalt, while the J4, J6, and J8 samples would be more prone to suffer mechanical failures such as rutting, cracking, or fractures due to thermal changes. The phase angle is very sensitive to the physical and chemical structure of modified asphalt binders. Figure 6 shows the isochronal curves of tan \(\delta\) of the modified asphalt blends with pistachio shells at an angular frequency of 10 rad/s. The addition of pistachio particles improves the elastic response of the asphalt binder since all of the modified asphalt curves are lower than the base binder. However, the comparison between Figures 5 and 6 suggests that the elastic effect at high temperatures that arises from the incorporation of pistachio particles is not as good as its corresponding analog containing _Jatropha_ particles for a fixed modifier concentration. However, the behavior of P4 and P8 samples (Figure 6) is comparable to that of J2 (Figure 5), which indicates that a content of 4% or 8% pistachio shell particles produces the best elastic behavior before flowing at high temperatures; contrarily, the P6 sample would be more susceptible to suffer the most common asphalt failures. Figure 4: Isochronal plots of \(\mid\)IG*\(\mid\)/sin \(\delta\) vs. temperature of asphalt modified by pistachio seed shell particles.
## 5 Conclusions  
The results achieved in this work demonstrate that homogeneous and dense (\(>\)98 th%) alumina--titanium carbide ceramic composites (with 30 and 40 vol.% TiC) were produced following a colloidal processing route, freeze drying method and spark plasma sintering. Al\({}_{2}\)O\({}_{3}\)-TiC composite with 40 vol.% TiC simultaneously improved fracture toughness (7.8 \(\pm\) 0.4 MPa\(\cdot\)m\({}^{1/2}\)) and hardness (22.3 \(\pm\) 0.3 GPa) of the composites, which is twice as high as the value for traditional Al\({}_{2}\)O\({}_{3}\)-TiC cutting ceramic (K01, ISO). The multiple actions of reinforcement in crack deflection and bridging were observed due to the presence of TiC particles.  
Besides improved mechanical properties, it was found that ceramic composites also possess electrical conductivity (higher than \(10^{-2}\) S\(\cdot\)cm\({}^{-1}\)) and consequently, this implies EDM machinability with the required complex shapes and high accuracy. This is more efficient than conventional machining operations such as diamond grinding, polishing, and lapping. Therefore, EDM allows the production of complex shapes and the machining of developed Al\({}_{2}\)O\({}_{3}\)-TiC composites, combined with a high degree of automation, which significantly increase the accuracy, speed, and cost-effectiveness of manufacturing.  
These composites can be processed into any intricate shape that makes it possible for them to be used in various applications, including miniaturized structures or indexable inserts for machining of hardened steel, difficult-to-machine materials, composites and other materials used in mechanical engineering.
# Edge-Computing Meshed Wireless Acoustic Sensor Network for Indoor Sound Monitoring
## 3 Sensor Design
### Assembly of the Nodes  
After the different components of the WASN nodes were selected, each node was assembled to contain:  
* **Single-board Computer:** a Raspberry Pi Model 4B of 4 GB RAM with an SD card of 64 GB and a heat sink.
* **Microphone:** An omnidirectional electret condenser microphone [35] with a flat frequency response between 50-18,000 Hz, a maximum sampling rate of 96 kHz/24 bit and a Signal-to-Noise ratio (SNR) of 84 dB. The microphone is connected to the Single-board computer using a USB 3.0 port.  
* **A 3D-printed designed box:** The box integrates the microphone sensor and the computing unit into a single element. Additionally, it offers protection against falls or undesired manual disconnections of the elements that compose the sensor.
* **Power supply:** a 5V-3A charger with USB-C connector powers the system.  
Figure 5 represents a sketch of the integration of the elements that compose each node as a low-cost sensor prototype. The characteristics of the protection box make this sensor suitable for indoor environments.
## 1 Introduction
To manage the prosumers in an energy sharing network, smart grid, with its communication infrastructure, allows consumers to form communities according to their energy consumption behavior [4]. This paper presents a novel Prosumer-based Energy Sharing and Management (PESM) scheme for cooperative DSM. Although implemented for a six-user scenario, the scheme is generic and applicable to any number of users. The rest of the paper is organized into four further sections. Section 2 is dedicated to related work on prosumer-based energy sharing. The proposed scheme along with associated scenarios is elaborated in Section 3. Section 4 presents simulations of the proposed scheme as well as analysis of the results. Conclusions are drawn in Section 5.
# Depth Evaluation of Tiny Defects on or near Surface Based on Convolutional Neural Network
## 3 Results and Discussion
### Neural Network Optimization
In this study, the neural network preparation was conducted using TensorFlow, training was conducted with various hyperparameters, and the determination of whether the model achieved the global optimum was based on the loss function values of the training set, as illustrated in Figure 10.  
From the graph, it can be observed that the three batch sizes selected in this study (16, 32, and 64) had minimal impact on the loss function. Even when the initial learning rates were set to 0.0001, 0.0002, and 0.0004, the loss function did not reach its minimum value even after 100 epochs, indicating that the model did not converge to the global optimum. However, when the initial learning rates were set to 0.001, 0.002, and 0.005, the loss function converged to its minimum value by epoch 15. Nevertheless, it is important to note that determining whether the model converges to a local or global optimum based solely on the loss function can be challenging. Therefore, further evaluation was conducted using a test set, and model performance was assessed based on the test set accuracy, as is shown in Table 3. The optimal batch size was found to be 32, and the optimal learning rate was determined to be 0.002 through a combination of loss function analysis and test set accuracy evaluation. Figure 10: The train loss for different batch sizes and learning rates: (**a**) batch size 16, (**b**) batch size 32, and (**c**) batch size 64.
# Evaluating the Functioning Quality of Data Transmission Networks in the Context of Cyberattacks
## 2 Related Work
The main restriction of the solutions obtained in [7; 8] is the limitation on the type of traffic transmitted in the network and the usage of individual exponential distributions characterizing the realization time of individual processes, namely, the transmission of an information packet and the formation and delivery of control transmission commands. Thus, the main disadvantage of the approaches discussed above is the lack of mechanisms for evaluating the impact of cyberattacks on the quality of the technological DTN function. In addition, the outlined related works are limited to the considered packet distribution laws in the DTN. The proposed method removes these restrictions.