esa-sceva/satcom-chunk-collection huggingface dataset:
# The Analysis of Service Convergence in an Optical Access Network +
## 4 Results and Discussion
### Comparison between LTE and UFMC  
In the evaluation of service convergence within the optical network, significant results were observed regarding optical reception power for both LTE and UFMC signals. The simulation demonstrated that the system effectively enables the transmission of both signals through the fiber optic channel, achieving a reception power of \(-30.987\) dBm for the UFMC and \(-26.987\) dBm for LTE, while maintaining a bit error rate (BER) within acceptable limits for service quality. These results highlight the system's capability to handle multiple high-demand services without compromising signal integrity, thereby demonstrating improved efficiency and performance in converged access networks. This optimized performance underscores the potential of optical networks to support the growing demands for data and connectivity in modern applications, paving the way for broader implementation of 5G technologies in existing networks. The results are shown in Figure 5 for LTE and in Figure 6 for the UFMC.  
Figure 4: The BER performance of the UFMC and GFDM under different modulation schemes (4-QAM, 16-QAM, etc.). The graph illustrates the relationship between the received optical power and the BER for each scheme, demonstrating the superior performance of the UFMC at lower power levels.  
Figure 5: Rx optical power vs. bit error rate from LTE.  
In addition, while latency and throughput are commonly used metrics in networking systems to assess overall performance, they are not the primary focus in the context of radio-over-fiber (RoF) systems. RoF technologies aim to optimize the quality of signal transmission over optical media, where metrics like bit error rate (BER) and Error Vector Magnitude (EVM) provide a more accurate representation of transmission fidelity. In this study, we concentrated on these signal integrity metrics because they directly reflect the effectiveness of optical signal conversion and transmission over fiber channels. The inherent low-latency nature of the optical fiber, coupled with the high data throughput of the medium, minimizes the variability in these metrics, making them less critical for evaluating RoF systems.
## 3 Current Status of the Circuit Component in the MMW Regime
### Low Noise Amplifier (\(\mathrm{LNA}\))
#### 3.1.1 LNA in CMOS Technology  
Figure 1 illustrates the measured minimum NF of the recent published MMW LNAs in CMOS technologies. In [49], not only wideband performance but also moderate NF are achieved by using resistive-feedback network, which is composed of a series gate inductor and a parallel tuning capacitor, and inductive-series peaking technique. In [50], a magnetic coupled technique incorporated with the multi-cascode configuration is proposed. The transformers in the multi-cascode configuration resonate the parasitic capacitances of the transistors out. Moreover, a V-band magnetic coupled triple-cascode LNA is proposed in [50], Figure 2 illustrates the circuit topology of the MMW low voltage triple-cascode LNA with magnetic coupled technique and the chip photograph is illustrated in Figure 3. The V-band triple-cascode LNA has a gain of 13.7 dB at 54 GHz and a NF of 5.3 dB at 59.5 GHz, with a power consumption of 14.4 mW at 1.2 V supply voltage. Compared with the conventional cascode LNAs, the use of the magnetic coupled technique in a multi-cascode LNA improves significantly the gain performance with a slight degradation of the NF.  
Figure 1: Measured minimum noise figure of the recent published millimeter-wave (MMW) complementary metal oxide semiconductor (CMOS) low noise amplifiers (LNAs). Data taken from [24, 46, 49, 50, 51, 52, 53, 54, 55, 56, 57].  
Figure 2: Circuit schematic of the V-band magnetic coupled triple-cascode LNA [50].  
In [46], the transformer multi-cascode topology is proposed to maximize the gain-bandwidth products, minimize the area and noise figure of the amplifier. These transformers in the multi-cascode configuration eliminate the effect of the parasitic capacitances of the transistors in the desired band, and thus the NF can be improved. In [51], the NF is reduced by the proposed voltage-voltage transformer feedback technique within the operation bandwidth of 6 GHz owing to the neutralization of the Miller capacitance. In [52], a novel gain-boosting technique is proposed. A 180\({}^{\circ}\) transformer is adopted to form the capacitive feedback path. In this manor, a high gain and low power LNA is designed and implemented with more degree of freedom compared with the conventional designs. In [53], the transformer between the gate and the source of the first stage results in simultaneous input impedance and noise matching. For further reduction of the path losses between the input and the output of the LNA, the drain-source transformers replace the matching networks, which are consisted of thin film transmission line or lump components. In [56, 57], the slow-wave CPW transmission line is utilized to reduce the loss of the thin-film transmission line in this frequency range; this leads to a low noise figure performances of the amplifier. In [24], the parasitic capacitances in the cascode configuration are resonated out for further reducing the noise figure of the five stages amplifier.
## 1 Introduction
The flow diagram of the proposed work is illustrated in Figure 1. The major contributions are:  
* The utilization of a lightweight encryption algorithm (LEA) in the data acquisition layer ensures data security during mobile user authentication, enhancing network integrity and user privacy. * Implementation of the Mud-Ring Algorithm (MRA) for optimal switch selection, preventing flow table overloading, and dynamically managing switch resources for efficient network operation. * The deployment of blockchain technology with searchable encryption and decryption techniques ensures the authenticity and reliability of flow rules, improving network resilience against malicious modifications. This innovation significantly strengthens network security. * The application of the BSHNN method at the domain controller layer enables real-time data packet classification and management of network traffic based on dynamic conditions and requirements. * Employing an enhanced adapting hidden attribute-weighted naive bayes (EAWNB) approach for identifying suspicious packets during data transmission. The remaining sections of the research work include: Section 2 gives an elaborate review related to intrusion detection in the SDN framework. Section 3 provides a detailed description of the proposed work, presenting comprehensive algorithms and mathematical models. Section 4 presents a concise discussion of simulations in the proposed work, along with a comparison to existing research. Section 5 concludes the research, outlining future scopes and implications.
## 3 Results and Discussion
The capacity of extracting compounds with different polarities indicates the versatility of the composites [41], and the presence of polypyrrole at the surface increases the lipophilic character of the composite even more, improving the extraction of more hydrophobic molecules, such as PRO. Moreover, the Relative Standard Deviation (RSD) values for extractions using polypyrrole were lower (from 2.8% to 28.8% for PPy-ALG and between 4.3% and 26.1% for ALG@PPy) when compared to neat ALG (from 12.6% to 40.7%), which indicates that the composite material is promising for extraction applications. This work complements previous publications regarding these types of composites. Here, we present a composite with an amphiphilic character capable of extracting low-to-medium polarity compounds, where a change in morphology--increasing the availability of polypyrrole at the surface--could improve the extraction of low polarity compounds (PRO). [PERSON] and coworkers [11] developed an alginate/zein (ALG:Z) hydrogel supported on polyppropylene fiber, capable of extracting medium-to-high polarity compounds. The device resulted in a simple and efficient sorption phase. In this case, the ALG hydrogel also presented better results for more polar analytes, such as ATZ, while the ALG:Z combination inferred an amphiphilic character in the extraction phase, since better extraction efficiency was reached for PRO. This work also evaluated the reusability of the material, performing 5 consecutive extractions with satisfactory standard deviation values (0.8-19.3%) and maintaining the mechanical integrity of the material. In another study, [PERSON] and coworkers [22] evaluated polypyrrole alone, in two different morphologies (globular and nanotubular), such as the extraction phase for ATZ, CAF, and PRO, using SPE and electrochemically controlled solid-phase extraction (EC-SPE) as pre-concentration techniques. In this case, polypyrrole again showed improved extraction of PRO, which can be associated with \(\pi\)-\(\pi\) interactions between the analyte PRO and PPy. Despite not being very selective, the morphology of PPy nanotubes showed the best performance associated with the increased surface area of the nanostructures. An increase was observed in the extraction efficiency of all compounds with lower RSD values (CV < 4.3%) due to the higher surface area.
# Fractal Cardioid Slot Antenna for Super Wideband Applications
## 2 Proposed Antenna and Parametric Sweep  
Numerous shapes of fractal antennas can be found in the literature, while those that satisfy the shapes of mathematical curves are particularly important.  
The antenna structure presented here is based on a slot in the form of more self-similar nested cardioids. The standard parametric mathematical expression for cardioid is the following [31; 32]:  
\[\begin{array}{l}x(\varphi)=a\cos\varphi(1-\cos\varphi)\\ y(\varphi)=a\sin\varphi(1-\cos\varphi)\\ 0\leq\varphi\leq 2\pi\end{array} \tag{1}\]  
where the parameter \(a\) scales the cardioids to the desired dimension. The proposed antenna has three cardioids that define its structure. Their scaling parameters, according to Equation (1), are \(a_{1}\), \(a_{2}\) and \(a_{3}\), as seen in Figure 1.  
The fractal shapes are characterized by two parameters: the iteration order (IO) and iteration factor (IF) [23]. The iteration order represents the number of fractal iterations, while the iteration factor represents the ratio of the dimensions of the second and first iterations of fractals. The iteration factor is always less than one because the last fractal dimension is always smaller than the previous one due to nested fractal geometry. Generally, in the majority of the proposed fractal antennas, the IF is the same for each iteration. However, in this paper, we propose a fractal antenna where the IF changes for each subsequent iteration. In this case, we can define IF\({}_{0}\), which represents the ratio between \(a_{2}\) and \(a_{1}\) and IF\({}_{1}\), which represents the ratio between \(a_{3}\) and \(a_{2}\). The IF for the zeroth iteration of the realized antenna is IF\({}_{0}=a_{2}/a_{1}=0.68\) and the IF for the first iteration is IF\({}_{1}=a_{3}/a_{2}=0.75\). It provides additional flexibility in antenna design.  
The antenna is designed for the FR-4 substrate of dielectric constant \(\epsilon_{r}=4.3\) and \(tan\delta=0.025\). The thickness of the substrate is 1.58 mm and the thickness of copper metallization is 0.018 mm. Parametric analysis was performed in order to obtain the maximum antenna impedance bandwidth; thus, the antenna can be used in energy harvesting applications without a lossy matching circuit between the antenna and detector. Simulations are performed in the time domain-based CST solver.  
The overall dimensions of the antenna are 35 mm \(\times\) 47 mm \(\times\) 1.61 mm, which classifies this antenna into a group of electrically small antennas [33]. The geometry of the proposed antenna is shown in Figure 1.  
Figure 1: The geometry of the proposed fractal antenna. The metal is shown in black. Relevant dimensions of the antenna are as follows: \(W=35.1\) mm, \(L=47.5\) mm, \(gap=0.25\) mm, \(W_{f}=2.85\) mm, \(L_{f}=16.4\) mm, \(g=0.40\) mm, \(L_{1}\)= 34.45 mm (distance from the cardioid center), \(L_{2}=42.43\) mm, \(a_{1}=6.6\), \(a_{2}=4.68\) and \(a_{3}=3.4\).
# Improved Mask R-CNN Combined with Otsu Preprocessing for Rice Panicle Detection and Segmentation
## 2 Dataset and Method
### Method
#### 2.2.2 Adjustment of the RPN Anchor Box  
The region proposal network (RPN) lightweight neural network was first proposed in the Faster RCNN algorithm, and the Mask R-CNN follows its basic structure and adds segmentation [24]. The RPN generates all possible target candidate regions through fixed window sliding on feature images extracted from the feature extraction network, and then maps these candidate regions to the original map through the region of interest alignment (ROI align) operation. Finally, it performs category classification, box regression, and mask generation on these candidate regions [25]. In the Mask R-CNN algorithm, the RPN generates a total of five different scales of anchor boxes, which are the five initial anchor boxes with set areas and proportions. By further fine-tuning their position and size, the best detection frame containing the target can be selected. Whether the setting of the initial anchor box is appropriate or not affects the prediction box accuracy. In this study, the anchor box size was appropriately increased and decreased from the original size under the same conditions for the experiments, and the optimal initial anchor box size was obtained by comparing the average accuracy (mean average precision, mAP).
## 2 Materials and Methods
### Datasets
#### 2.2.5 Hydrological Data  
In this study, daily streamflow and sediment concentration data from the Srikakulam station in the Nagavali watershed and the Kashinagar station in the Vamsadhara watershed were used. These data obtained from the Central Water Commission (CWC), Orissa, India. The yearly average streamflow in the Nagavali and Vamsadhara watersheds is 79 m\({}^{3}\)/s and 82 m\({}^{3}\)/s, respectively, with an annual average sediment load of 3.7 million tons in both basins.
# A Novel Overcurrent Suppression Strategy during Reclosing Process of MMC-HVDC
## 4 Simulation
### The Validation of the FCL  
For the test system, a pole-to-pole fault F\({}_{1}\) is applied at the DC outlet of MMC1. The overcurrent in MMC1 is the most serious, and thus it will be taken as the example for simulation. When the RCLR R\({}_{12}\) is configured, the equivalent circuit in Figure 4 is modified as Figure 8 and Equation (1) is modified as Equation (6). The upper and lower limitation of the RCLR are set to 0 and 15 \(\Omega\), respectively, and the calculation step is 0.1 \(\Omega\).  
\[\left[\begin{array}{ccc}1&0&0\\ 1&0&-1\\ 0&1&-1\\ 0&1&0\end{array}\right]\left[\begin{array}{ccc}u_{c1}\\ u_{c2}\\ u_{c3}\end{array}\right]=\left[\begin{array}{ccc}2R_{12}+R_{1}&R_{1}&0&0\\ R_{1}&2r_{13}+R_{1}+R_{3}&R_{3}&0\\ 0&R_{3}&2r_{23}+R_{2}+R_{3}&R_{2}\\ 0&0&R_{2}&2r_{12}+R_{2}\\ \end{array}\right]+ \tag{6}\] \[\left[\begin{array}{ccc}2L_{12}+L_{1}&L_{1}&0&0&0\\ L_{1}&2(L_{13}+L_{31}+l_{13})+L_{1}+L_{3}&L_{3}&0\\ 0&L_{3}&2(L_{23}+L_{32}+l_{23})+L_{2}+L_{3}&L_{2}\\ 0&0&L_{2}&2(L_{21}+L_{13})+L_{2}\end{array}\right]\left[\begin{array}{c}i_{ 14}\\ i_{13}\\ i_{23}\\ i_{24}\end{array}\right]\]  
By solving (2) and (6), the relation between the maximum arm current and the critical resistance R\({}_{0}\) of FCL can be obtained, as shown in Figure 9.  
Figure 8: The equivalent circuit of SMs discharging with reclosing current limiting resistance (RCLR).  
Figure 9: The maximum calculated arm currents with the different RCLR.  
Take \(k=1\), \(k=0.9\) and \(k=0.8\) for examples to verify the effectiveness of the proposed calculation method. Figure 10 shows the DC currents on the faulty line where 'k = \(\times\)' means without RCLR (only using the CLI). Figure 11 shows the arm currents in MMC1 under different current limiting levels.  
As is observed in Figures 10 and 11, serious overcurrent still exists without RCLR during reclosing, and the converter is blocked again when reclosing the DCCB leading to the interruption of power flow for a long time. However, by using the proposed RCLR, the fault currents in both the faulty line and converter will be reduced significantly during reclosing, and the converter can keep continuous operation without blocking. As it is observed in Figure 12, the maximum value of arm current under different current limiting level is close to but less than the specified value and the converters are not blocked during the reclosing process. The proposed method can meet the overcurrent limiting requirement with a lower resistance value proving the calculation method is accurate and effective.  
Figure 11: Arm current and blocking signal without RCLR.  
Figure 10: MMC1 DC fault current in _line_\({}_{12}\).
## 2 System Design  
The self-powered sensor node for CO\({}_{2}\) monitoring within transformer substations, along with the prototype of the proposed piezoelectric energy harvester, is depicted in Figure 1. The self-powered sensor node comprises a multiple-cantilever PEH, a microcontroller-based sensor node equipped with a CO\({}_{2}\) sensor module, and a wireless module, as illustrated in Figure 2. Additionally, the multi-layer piezoelectric cantilever system is composed of three identical piezoelectric beams that are stacked vertically. A proof mass is affixed to the free end of the multi-layer PEH to fine-tune its resonant frequency. This PEH is subjected to excitation in the vertical direction.  
The key advantage of the proposed PEH comes from the multiple-layer configuration of the cantilever. Multiple piezoelectric cantilevers are assembled to enhance the resonant frequency of the PEH. In addition, the S-shape vibration mode is also shown in Figure 1b. The vibration mode was obtained using a Finite Element Method (FEM) simulation using COMSOL Multiphysics 6.1. In the FEM analysis using COMSOL, hexahedron element and linear element orders were used. The COMSOL model consisted of three 75.18 \(\times\) 20 \(\times\) 0.16 mm\({}^{3}\) stainless steel cantilevers. Six PZT-5H piezoelectric transducers with identical dimensions of 15 \(\times\) 20 \(\times\) 0.2 mm\({}^{3}\) were glued at the root and free end of the cantilevers. A magnetite-based proof mass was introduced to provide additional constraints for the bending of the three beams. A fixed constraint was added on the base of the fixed end of the cantilever beam as the boundary condition. The modal shape of the beam was evaluated through Eigenfrequency analysis.  
It can be seen that each section of the cantilever is undergoing an S-shaped bending motion, as shown in Figure 2. The proof mass introduced additional constraints, ensuring that the free ends of the cantilevers experienced no rotation, which would result in significant bending moments. Hence, the torques in the longitudinal direction of the piezoelectric cantilever were decreased to zero and then increased from the free end to the fixed end of the beam. In other words, both the fixed and free ends of the beam undergo strain concentrations. As a result, piezoelectric transducers were mounted at the tip of the beam. This would further increase the system-level stiffness of the cantilever, thereby raising the  
Figure 1: (**a**) PEH for transformer monitoring; (**b**) self-powered sensor node.  
Figure 2: (**a**) Prototype of the proposed multiple-cantilever PEH; (**b**) s-shape vibration mode.  
resonant frequency to match that of the transformer substation. Piezoelectric transducers can be attached at both the fixed and free end of the beam to increase the power output.
## 2 Concept of Micro-Grid Systems
### Power Electronics Converter Control
#### 2.2.1 Primary Controller  
A primary controller consists of an inner loop (current/voltage regulation) and droop control (preliminary power sharing) based on the control of the power converters. The response time of the primary controller is very short, and there is no need for communication when it is utilized in the decentralized system [36]. But when it is used in centralized control, distributed control, and master-slave control, there is a need for communication. This controller is mostly used for regulating the frequency and voltage of the inner loop of control.
# Augmented Reality-Based Framework Supporting Visual Inspection for Automotive Industry
## 2 AR in the Industry
However, AR applications are usually customized for specific industry needs, so it is impossible to commercialize them, especially considering the high cost of commercial implementation. For that, very few works of AR-assisted inspection can be found. One of the examples of inspection-based AR is presented by Bosh in [21], where the company implements its own marker-less connected repair software for the vehicle equipment's diagnostic (see Figure 1a). The implemented system does not only identify fault sources in the vehicle but also guides the operator for efficient diagnosis and repair by exhibiting the tasks that need to be performed. Volkswagen has also built a marker-less augmented reality system named MARTA (Mobile Augmented Reality Technical Assistance) for the XL1 model (see Figure 1b). MARTA shows the operator the list of tasks to be realized during the inspection process while giving the possibility of assisting the correction phase by adding to the real scene instructions in front of the operator [22]. Another AR solution in the automotive industry is described in [23], where authors have implemented an AR system for underhood inspection and maintenance (see Figure 1c). Similarly, in [24], the authors have designed and implemented a Marker-based Spatial AR system for Spot welding inspections. The proposed AR system relies essentially on the data projection technique, which serves in this use case to display the information related to weld defects (see Figure 1d). In all the above-mentioned works, authors have proved the effectiveness and efficiency when adopting AR to carry out inspections. The results of these works show that disposing of manual-based or even computer-based inspection techniques leads to a significant gain of time with higher accuracy of tasks accomplished. Despite that few works exist for AR-assisted inspection, the existing results when adopting AR and the advancement we face in the technology should encourage researchers to work more on this technology, especially in the industry field when its adoption may serve productivity increase.