esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Related Work
Securing wireless sensor networks for improved performance in cloud-based environments is proposed [34] by modifying the low-energy adaptive clustering hierarchy (LEACH) protocol. The proposed solution has added intrusion detection functionality for securing the sensor nodes from sinkhole, black hole, and selective forwarding attacks. The simulation and numerical results of the modified protocol (LEACH++) have proven significant security, throughput, and energy consumption. Authors in [35] introduced a Secure Smart Health system with privacy-aware aggregate authentication and access control in IoT. The proposed solution enables a privacy-aware aggregate authentication using an anonymous certificateless aggregate signature scheme. Additionally, privacy-aware access control is based on anonymous attribute-based encryption technologies. The extensive experimental results demonstrate the improved performance relative to computational cost and communication overheads. In [36], research was performed and an IoT-based smart health framework was developed by focusing on interoperability issues. The particular requirements for IoT networks were analyzed and provided a basis for the design of the developed framework. The performed experiments exhibited that interoperability among various IoT devices, protocols and standards in a smart health system could be achieved using a specialized gateway device. Moreover, different web technologies could be used at the same time under restricted and Internet environments. The discussion of the related work reveals that constraint resources have a significant role in gathering field data for further analysis for appropriate medical decisions. Most healthcare applications depend on such an IoT network to observe the patients'data and deliver the information on time to the cloud paradigm. However, their limitations, especially in terms of limited resources, pose significant challenges for wireless and unpredictable communication models. Additionally, it is observed that most of the cloud-oriented solutions remarkably decrease the computational and communication costs for IoT-based transmission systems. However, providing security in the presence of leakage and malicious attacks imposes additional network overhead. It is also observed that minimal solutions have been proposed for network resiliency and offer data routing in a non-optimal manner in terms of longer constancy and heavy sensor traffic. Therefore, the research community is still focused on presenting a resilient approach to coping with data management integrated cloud systems to overcome vulnerabilities in the healthcare system and help patients and medical professionals [37; 38; 39; 40].
## 3 The Proposed Circuits
### The Full Adder (FA) Circuits' Design  
In this section, we designed and implemented two full adder (FA) circuits using the proposed XOR gate. The design was carried out with a delay of only three clock phases (0.75 clocks). The FA circuits proposed in this research are among the best samples ever designed. This is because they are designed without the use of a NOT gate, rotational cells, and crossovers, and they are designed to be coplanar. Equations (4) and (5) below are relationships related to the full adder circuits; Table 1 is its truth table; Figures 13 and 14 present, respectively, a block diagram and implementation of the a and b proposed FA circuits with QCA technology; and Figure 15 shows the simulator output of these FA circuits.  
\[\text{S}=\text{A$\oplus$B$\oplus$Cin}=\text{AB$Cin}+\text{A$B$'Cin}+\text{A$B$' Cin}^{\prime}+\text{A$B$Cin}^{\prime} \tag{4}\]  
\[\text{Cout}=\text{M}\text{(A, B, Cin)}=\text{A.B}+\text{A.Cin}+\text{B.Cin} \tag{5}\]  
Figure 11: The proposed XNOR gate.  
Figure 10: Logical diagram of the proposed 5-input XOR gate.  
Figure 12: Simulation results for the proposed XNOR gate.  
Figure 13: Logical diagram of the proposed full adder (FA) circuits.  
Figure 14: The proposed full adder (FA) (**a**) FA design-1 (**b**) FA design-2 circuits.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**A** & **B** & **Cin** & **S** & **Cout** \\ \hline
1 & 1 & 0 & 0 & 1 \\
1 & 1 & 1 & 1 & 1 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Truth table of the full adder/subtractor.  
Figure 15: Simulation results for the proposed XOR gate.
# A Study on the Stress Field Around an Elliptical Wellbore with an Eccentric Casing in Deep Wells
## 3 Result Analysis and Discussion
### The Influence of Poisson's Ratio of Cement Sheath on Casing  
4.1 The Influence of Poisson's Ratio of Cement Sheath on the Maximum Stress Component and Equivalent Stress of Casing  
According to the results in Figure 14, we can observe the distribution of maximum stress on the outer wall of the casing at different eccentricities when the casing, formation  
Figure 13: Maximum stress distribution on the outer wall of casing under different elastic moduli of cement sheath. (**a**) Radial stress; (**b**) circumferential stress; (**c**) shearing stress; (**d**) equivalent stress.  
elastic parameters, and boundary conditions remain unchanged but the Poisson ratio of the cement sheath is varied. In the figure, as the Poisson ratio increases, the stress values on the outer wall of the casing at different eccentricities show a decreasing trend. This indicates that increasing the Poisson ratio of the cement sheath can reduce the stress values in the casing.
# Virtual Prototyping: Computational Device Placements within Detailed Human Heart Models
## 3 Results and Discussion
Figure 5: 3D human heart model (HH229) with computationally added vasculature. A MicraTM transcatheter pacing system delivery catheter and a MicraTM were computationally implanted in the right ventricular apex. During early MicroTM TPS development and physician feedback sessions, it was questioned if more than one MicroTM TPS could be implanted within a patient's heart (e.g., for end of device life replacement). Thus, designers needed to understand that the large volume of the right ventricle would allow for the placement of non-interacting concomitant MicroTM TPS within the same chamber. Fresh human cadaveric studies were performed on a small set of human hearts [9]. In Figure 7, we can visualize that a second MicroTM TPS was computationally deployed within this detailed cardiac anatomy, to simulate the spatial conditions where multiple MicroTM TPS were implanted within a patient's right ventricle. The heart model was sliced along the coronal plane to reveal a four-chamber view of the posterior half of the heart. The model was then 3D printed for further analyses and educational use (Figure 7). In another example of the value of computationally placed cardiac devices within these detailed human heart models, a Medtronic Arctic Front cryoballoon catheter was computationally placed within a human heart model (Figure 8). This human heart model had vasculature from a cadaver computationally added to simulate the delivery pathway required to navigate the cryoballoon from the  
Figure 6: 3D models and 3D print of the posterior half of a human heart (HH229) with a computationally placed MicroTM transcatheter pacing system (TPS) and delivery catheter. The printed heart and MicroTM TPS were hand painted to highlight device–tissue interfaces. Figure 7: Multiple MicroTM transcatheter pacing systems computationally implanted in the right ventricular apex of a 3D human heart model (HH229; left) and resulting 3D print that was hand painted to study device–issue interfaces (right). access point within the femoral vein, proximally up to the left superior pulmonary vein ostia within the left atrium. This ablation balloon placement procedure requires an initial atrial transseptal puncture, which here was computationally placed into an anatomically accurate location on the atrial septal wall of the human heart model. The resulting computational model was 3D printed and has been utilized as an educational tool to explain the necessary steps of this complex procedure to medical students, residents, fellows, clinicians, patients, and/or medical device designers.
## 3 Results and Discussion  
In order to validate the proposed scheme, numerical simulations based on the Virtual Photonics Incorporated Transmission Maker (VPI TM) 9.0 (product of VPIphotonics company in Berlin of Germany) with co-simulations of Matrix Laboratory (MATLAB) were conducted. The schematic of the simulated system followed Figure 1 with some simplification. In the simulations, both the LSB and RSB were assumed to include two sub-bands making four ONUs in total. For each ONU, a pseudo random binary sequence (PRBS) with \(2^{18}\) bits was used for QAM modulation and a root-raised-cosine (RRC) filter with a roll-off factor of \(\beta=0.1\) was used as the shaping filter with a symbol rate of \(Rs=12.5\) Gbaud. It is well known that the roll-off factor is an important parameter for both system performance and SE [19]. In order to achieve a high SE for the PON system, a small roll-off factor of 0.1 was chosen in this work. In addition, 16-QAM modulation was used for CAP signal generating. Due to the non-ideal filtering effect of the OBPF to separate the LSB and RSB signals, a guard band of \(GB\) was applied to reduce the residual crosstalk from the opposite sideband. Two sub-bands from LSB were used for ONU1 and ONU2 while the other two sub-bands from RSB for ONU3 and ONU4. The central frequencies of the sub-bands were then found to be \(f_{1}=-GB-3 Rs(1+\beta)/2\), \(f_{2}=-GB-Rs(1+\beta)/2\), \(f_{3}=GB+Rs(1+\beta)/2\) and \(f_{4}=GB+3 Rs(1+\beta)/2\), respectively. In the simulations, the sub-band signals in LSB or RSB satisfied the summed signal as in Equation (1).  
For the cost consideration, a dual-drive Mach-Zehnder modulator (DDMZM) was used to generate the SSB signal simultaneously with the required optical carrier [17]. To achieve this, the real and imaginary parts of the twin-SSB signal were fed into the two arms of the DDMZM, which were biased at the quadrature point. The optical source used in the simulation had a working wavelength of 1550 nm. The laser linewidth was assumed to be 1 MHz for low-cost operation. Standard single-mode fiber (SSMF) with a length of 50-km was assumed for long-reach PON in this work. The attenuation coefficient of the SSMF was set at 0.2 dB/km. Other parameters of SSMF included dispersion coefficient D of 16 ps/nm/km, and nonlinear index of 2.6 \(\times\) 10\({}^{-20}\) m\({}^{2}\)/W. The optical signal to noise ratio (OSNR) was set to 35 dB by adding Gaussian white noise. The responsivity and dark current of the PD were set to 0.85 A/W and 0.5 nA. After the received signal was obtained as in Equation (2) by a square-law operation, the summed SSB signal was reconstructed by the KK-receiver shown in Figure 1. For this purpose, the phase signal was firstly obtained using Equation (3) based on the received signal. Then, the complex signal was reconstructed by combining the recovered magnitude and phase of the signal as in Equation (4).
## 7 Simulations and Results  
Simulations with the three presented forecasting models have been performed to compare the relative accuracy and reliability when applied to the four chosen indicators. ARIMA, traditionally the standard model for healthcare time-series predictions, is used as a benchmark.  
Observing the ACF (Auto Correlation Function) and initial model training, a strong correlation was found by hour and weekday, so data have been classified by these parameters when applying the models. Further to the classification, it was observed that the autocorrelation of the data was stronger in the 8 weeks prior to the forecasting, as the residuals when utilizing this interval were the smallest in simulations. Summarizing, each prediction \(\hat{y}\) was calculated using a rolling actuals timeseries subset of the 8 previous observations, classified with a lag = 168.  
The subset of 8 observations means that when applying GRNN, the size of the input layer was equal to 8, although the number is small, it presented smaller residuals than trials with sizes of input layer ranging from 12, 20 and 30, this is believed to be due to the higher correlation of the data observed in the ACF. The sigma parameter for the GRNN was chosen to be 0.3, which was found to be the best fit in preliminary experimentation.  
Each model has been trained until its residuals were minimal in simulations, then parameters fixed and subsequently applied to the same rolling actuals time-series subset, of the same data source, with equal periods and frequency. Predictions were then compared with actual values and analysed for accuracy and reliability over the period from 1 January 2020 to the end of October 2020. Each prediction made is hourly and has an event horizon of \(h\) = 168 h, corresponding to predicting every hour for 7 days in advance.  
The results are presented in a number of figures showing actual observed values, predictions and residuals and then analysed in Section 8.
# On the Impulse Response of Singular Discrete LTI Systems and Three Fourier Transform Pairs
## 4 Equivalence to the Unit Impulse Response Function  
### Relationship of \(h_{3}[n]\) and \(h_{2}[n]\) with \(h[n]\)  
**Theorem 2**.: _If \(N\geq 2\big{(}L_{y}+1\big{)}\), \(h_{3}[n]=h[n]\) for \(n<\frac{N}{2}-L_{l}\) when \(\frac{N}{L}\) is even; and \(h_{3}[n]=h[n]\) for \(n<\frac{N-L}{2}-L_{l}\) when \(\frac{N}{L}\) is odd._  
Proof.: Case 1: \(\frac{N}{L}\) is an even integer.  
From the definition of \(h_{1}[n]\) and \(h_{2}[n]\), we have  
\[h_{2}\bigg{[}n+\frac{N}{2}\bigg{]}=\frac{2}{NL}{\sum_{m=0}^{L_{y}-1}y[m]}+ \frac{1}{N}{\sum_{m=0}^{L_{y}-1}y[m]}{\sum_{k=0}^{N-1}F_{1}(k,\ m-n)e^{j\pi k}} \tag{26}\]  
From Equation (9) and Lemma 2, we have  
\[h_{3}[n]=\frac{2}{N}{\sum_{m=0}^{L_{y}-1}y[m]}(q_{1}[n-m]+q_{1}[n+L_{l}-m]). \tag{27}\]  
The minimum value for \(n-m\) is \(-L_{y}+1\). When \(n+L_{l}-m<0\), \(q_{1}[n+L_{l}-m]\big{)}=q_{1}[N+n+L_{l}-m]=0\) since \(N+n+L_{l}-m\geq N-L+2\). \(q_{1}[n-m]=q_{1}[n+L_{l}-m]=0\) under the condition that \(N\geq 2\big{(}L_{y}-1\big{)}\). When \(n+L_{l}-m\geq 0\) and \(n-m<0\)  
Figure 6: Example plots to show that the summation expressed by (20) is the same as the closed form expressed in (20a).  
\(q_{1}[n-m]=q_{1}[N+n-m]=-q_{1}\Big{[}\frac{N}{2}+n-m\Big{]}=-q_{1}[n+L_{l}-m]\) under the condition that \(N\geq 2(L_{y}+1)\). Thus, when \(n-m<0\), \(q_{1}[n-m]+q_{1}[n+L_{l}-m]=0\) if \(N\geq 2\big{(}L_{y}+1)\). When \(n-m\geq 0\) and \(n+L_{l}<\frac{N}{2}\), \(q_{1}[n-m]=q_{1}[n+L_{l}-m]\) as \(L_{l}\) is zero or a multiple of \(L\). Thus,  
\[h_{3}[n]=\frac{4}{N}{\sum_{m=0}^{L_{y}-1}}y[m]q_{1}[n-m]={\sum_{m=0}^{L_{y}-1} }y[m]q[n-m]+h[n-L]u[n-L]\] (27a) This is the same as Equation (2). Therefore, if \(N\geq 2\big{(}L_{y}+1)\), \(h_{3}[n]=h[n]\) for \(n<\frac{N}{2}-L_{l}\).  
In order to produce \(M\) points (corresponding to index \(n=0:M-1\)) accurately in \(h_{3}[n]\), the minimum \(N\) required is \(N_{min}=2 max\big{(}L_{y}+1,L\big{)}+2L_{y}-2 mod\big{(}L_{y},L\big{)}-1\). For example, if \(L_{y}=4\), \(L=3\), \(N_{min}=4L_{y}-1=15\). Since \(N/L\) needs to be an even integer, \(N\) should be 18 to authentically produce the first five elements.  
Case 2: \(\frac{N}{L}\) is an odd integer  
Similar to Case 1 and applying Equation (10) for odd \(N/L\) and Lemma 3,  
\[h_{4}[n]=h_{3}[n]+(h_{4}[n-N_{h-}+L_{l}]+h_{4}[n-N_{h-}+L_{l}-L])/2. \tag{29}\]  
However, the author is unable to obtain a proof at this point.
# Iterative MLFMA-MADBT Technique for Analysis of Antenna Mounted on Large Platforms
## 5 Conclusions  
A new iterative MLFMA-MADBT hybrid method is proposed to solve the complex radiation problem of the antennas mounted on large platforms. A transition region surrounding the junction of the antenna and the platform is strictly considered, which can guarantee high accuracy.The MLFMA region is regarded as a point source and the pyramid beams correlated with the source are modeled by the FAFFA-MLFMA to compute the interaction from the MLFMA region to the BT region. Then the MADBT method for the radiation analysis is applied to consider the multi-bounce effects within the platforms without any matrix operation. The numerical results show that the computations of the proposed method consume mush less memory and time than the MLFMA and the MLFMA-PO. Furthermore, under the premise of good efficiency, the proposed method obtains obviously better accuracy than the MLFMA-PO especially for the corner reflector structures, which indicates that the proposed method is especially suitable for the complex platforms with multiple reflections. In addition, it is necessary to point out that the iterative MLFMA-MADBT method is mesh-independent not only for the flat platform but also the platform with curved surfaces.  
Conceptualization, M.P. and H.W.; methodology, M.P. and H.W.; software, M.P.; validation, M.P., H.W.; formal analysis, H.W.; investigation, H.L.; resources, H.L.; data curation, H.L.; writing--original draft preparation, M.P. and H.W.; writing--review and editing, H.W., H.L. and M.P.; visualization, H.W.; supervision, H.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Key Research and Development Program of China (Grant No. 2020 YFC2201302).  
The authors declare no conflict of interest.
## 4 Conclusions  
The survey leads to the following main conclusions:  
* There are about 290 MBR plants in Italy, and they are located mainly in the most industrial area of the country. The number of municipal plants that provided information is 106, and they serve about 2 million PE, corresponding to approximately 3% of the total organic load treated by the Italian WWTPs with secondary and advanced treatments;
* Flat-sheet membranes are more spread than hollow-fiber ones, above all in small installations. In the case of hollow-fiber membranes, high area per unit volume, cost effective fabrication process, and capability to withstand severe operating conditions make them attractive. Recently, hybrid membranes were utilized in few plants;
* The main drivers for the installation of the MBR system are the lack of space and the necessity to increase the treatment capacity of existing plants, both in the case of industrial and municipal wastewater;
* The opinion of the plant managers is substantially positive. In particular, the reliability in the compliance with the discharge limits, the improvement of the plant capacity and, above all, in the industrial installations and the automation of the process are very appreciated features. However, some critical aspects remain, such as membrane fouling and plant shutdown, on which the MBR technology producers are required to give effective answers.  
**Supplementary Materials:** The following are available online at [[https://www.mdpi.com/article/10.3390/app12136559/s1](https://www.mdpi.com/article/10.3390/app12136559/s1)]([https://www.mdpi.com/article/10.3390/app12136559/s1](https://www.mdpi.com/article/10.3390/app12136559/s1)), Questionnaire S1: Questionnaire used for the census of MBR plants; Questionnaire S2: Questionnaire used for the survey on operational aspects.  
**Author Contributions:** Conceptualization, M.V. and C.C.; methodology, A.A.; validation, M.V. and G.B.; data curation, A.A.; writing--original draft preparation, A.A.; writing--review and editing, M.V.; visualization, G.B.; supervision, M.V., G.B. and C.C. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Acknowledgments:** The authors wish to thank the MBR technology suppliers and the managers of the MBR plants which provided information in this survey. A2A Ciclo Idrico, Acea, Arpa Lombardia, ASM Voghera, Bema, CAP Holding, Depurazione Trentino Centrale, Depurazione Trentino Occidentale, Emilia Ambiente, Evoqua, General Electric, Ghezz International, Hera, Idroclean, Idrotigullio, Ingeco, Iren, Koch, Kubota, Latte Arborea, M.G., Microdyn Nadir, Multiservizi, Padania Acque Gestione, Pavia Acque, Provincia Autonoma di Trento, Setam, Siba, Sifagest.  
**Conflicts of Interest:** The authors declare no conflict of interest.
# Ultra-Wideband Analog Radio-over-Fiber Communication System Employing Pulse-Position Modulation
## 3 Experimental Setup
### RAU Transmitter  
As for the optical receiver, a Discovery Semiconductors DSC10H p-i-n photodiode (PIN) with 50 GHz 3-dB electrical bandwidth with a sensitivity level +4 dBm for BER of \(10^{-12}\), the dark current of 5 nA and responsivity of 0.65 A/W was used, which realized the photodetection-based RF generation from the optical beat-note. A broadband optical power meter and an optical spectrum analyzer were used at the end of the fiber line to measure and optimize the received optical power, which was later disconnected and replaced by the PIN after optimization. The optical spectra before the PIN can be seen in Figure 5. The RF signal output power from the PIN was limited. Therefore, the RF signal is amplified by a 38 GHz and +29 dB gain broadband amplifier (SHF 810) before being transmitted to the Ka-band (26.5-40 GHz) horn-type antenna with 20 dBi gain. Free space path loss of the transmitted 28 GHz signal at 5 m was 35.36 dB; at 10 m, it was 41.38 dB, and at 20 m it was  
Figure 4: Experiment setup of ARoF-based UWB communication system employing PPM, (**a**) ARoF transmitter, (**b**) RAU transmitter, (**c**) RAU receiver.  
47.40 dB. As one can see from the calculations, the most critical insertion losses are at the beginning of the transmission distance.  
In Figure 5, the Kerr nonlinear optical effects (NOE), e.g., the four-wave mixing (FWM) impact on the PPM modulated intermediate frequency optical signal, is illustrated, which affects the signal transmission through the optical distribution network. Additional spectrum peaks are caused by the high optical power level output (\(\sim\)+15 dBm) of the second EDFA before launching the optical signal in the 20 km long SMF optical distribution network and are more pronounced than in the case of the back-to-back setup due to the nonlinear coefficient and the mode effective area of the SMF. Nevertheless, this does not significantly impact the BER, as NOE does not considerably affect PPM signals. The optical power of the three optical tones after the 20 km long SMF is about 3 dB lower due to the attenuation in the fiber.