esa-sceva/satcom-chunk-collection huggingface dataset:
# Preparation of an Asymmetric Membrane from
## Materials and Methods
### Characterizations and Analysis Methods  
The functional groups of the materials were analyzed using an ATR-FTIR spectrometer (Bruker, Karlsruhe, Germany). X-ray diffraction (XRD) measurements were carried out using a D8 Advanced (Bruker, Karlsruhe, Germany), anode X-ray Diffractometer with Cu K\(\alpha\) (\(\lambda\) = 1.5406 A) radiation. The thermal analysis of cellulose acetate and asymmetric membranes was made via DSC and TGA using Labsys Evo at a heating rate of 10 \({}^{\circ}\)C/min in a temperature range from 30 to 500 \({}^{\circ}\)C under argon flow (20 mL/min). The surface and cross-section morphologies of as-prepared membranes were studied by SEM (Nova nano SEM 450 FEI, Eindhoven, Netherlands). Surface properties of the membranes were analyzed with a Dimension Fast Scan AFM device ([PERSON], Karlsruhe, Germany), in which the measuring area of each membrane sample was 1 \(\upmu\)m \(\times\) 1 \(\upmu\)m. A contact angle goniometer (OCA20, Data physics Instruments GmbH, Filderstadt, Baden-Wurttemberg, Germany) was used to test the water contact angles of the membranes. The as-prepared membranes were immersed in deionized water at room temperature for 24 h to determine the water content. Afterwards, the surface of the membranes was mopped with tissue paper and weighed immediately. Then, these membranes were dried in a vacuum oven at 60 \({}^{\circ}\)C for 12 h, and the dry membranes were weighed. After that, these dry membranes were again placed in a vacuum oven until constant weight. The water content (\(W_{C}\)) was calculated by Equation (3):  
\[W_{C}=\frac{W_{w}-W_{d}}{W_{w}}\times\,100\% \tag{3}\]  
where \(W_{w}\) and \(W_{d}\) are the weights of wet and dry membranes, respectively.
# Modelling, Analysis and Performance of a Low Inertia AC-DC Microgrid
## 4 Simulation Results
### Model Verification  
Figure 11 depicts the dynamic response of the proposed system using the Simulink nonlinear model and the linearized small-signal state-space model under the same conditions and operating point. The VSC is controlled by the virtual inertia loop based on the HPF and the contingency is introduced on the AC side by increasing the load torque of the induction machines by 3%. The grid frequency and DC link voltage responses verify that the system produces identical results when either the state-space model or the non-linear model is used. When the operating point stays close enough to the linearization point, the results show that the two models well depict both the fast and slow transients in the system. This result shows that the linearized model is valid around the steady state operating point and can be used with conventional linear system analysis methods to evaluate system stability and study the impact of parameter variations.
## 3 Data Processing
### Image Pre-Processing  
Input images are pre-processed to avoid certain reflectivity aberrations. The tasks are:  
* The compensation of the linear variation of the reflectivity information along the slant-range dimension. This is performed by multiplying each azimuth line at range position \(r_{i}\) with a constant \(C_{i}\). This constant is computed as the ratio between the mean value of the whole image and the mean of all the values within the azimuth line \(r_{i}\).
* The application of the calibration constants to retrieve the Radar Cross Section (RCS).
* The erasing of guard bands at image edges with null values. Some data present areas at image edges with no useful information. They are erased with morphological operations.
# Secrecy Enhancing Scheme for Spatial Modulation Using Antenna Selection and Artificial Noise
## 6 Conclusions  
In this paper, we presented a new secrecy-enhancing scheme for the SM system. The proposed scheme employed two AN sequences, which were designed to be canceled each other perfectly only at the legitimate receiver. The AN sequences were designed by exploiting imperfect CSI of the legitimate channel by considering a practical system environment. In addition, an optimum antenna selection scheme was proposed by reducing the complexities of finding the solution from the exhaustive search. With the proposed scheme, the passive eavesdropper would suffer from the interference induced by the AN, resulting in secrecy rate enhancement of the legitimate receiver. We analyzed the secrecy performance over a Rayleigh fading channel by considering imperfect CSI. The simulation results demonstrated that the secrecy performance of the proposed scheme was enhanced compared to the conventional scheme.  
Conceptualization, P.S. and X.-Q.J.; data curation, P.S.; funding acquisition, S.K.; software, W.Y. and K.Z.; supervision, S.K.; validation, X.-Q.J.; writing, original draft, P.S.; writing, review and editing, S.K.  
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2017R1D1A1B03027939).  
The authors declare no conflict of interest.
# A Multichannel, High-Bandwidth Wirelane Receiver for D2D Interconnects
## 4 Results  
The transceiver can be supported in a D2D interconnect with a channel length of 50 mm. Figure 23 shows the circuit layout of a transceiver system that works at 512 Gbps. The central part of the clock path data includes the MINI-PLL layout, all-digital CDA layout and PI layout designed in this research. There are 16 pairs of differential data paths on the upper and lower sides of the overall layout. The transceiver system uses 9 ML(nine-metal-layer) 28 nm CMOS technology, and the receiver occupies a 0.9 mm \(\times\) 2 mm silicon area.  
The power consumption of the receiver is shown in Figure 23b. In the receiver, the analog part consumes 137 mW (61%) for CTLE, 1/4 sampler circuit, PI and clock. The power consumption of the digital part (21%) mainly includes 4:16 DMUX and 16:64 MUX, and the total power consumption is 45 mW. The phase-locked loop of the receiver uses a forward clock structure, and the power consumption is only 36 mW (8%). The transceivers share a bias circuit and its power consumption is 14 mW, so the power consumption (3%) of the bias circuit in the receiver is taken as half. Others which is used for the clock is 16 mW (7%).  
Figure 23: (**a**) Layout design, (**b**) power consumption ratio of each module in receiver.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Type** & **DNL** & **INL** & **Power Consumtion** & **Precision** & **Technology** \\ \hline
[17] & 0.89 LSB & 2.18 LSB & 3.4 mW & 8 bit & 65 nm \\ \hline
[18] & — & 1.64 LSB & — & 8 bit & 32 nm \\ \hline This work & 0.54 LSB & 0.68 LSB & 10 mW & 8 bit & 28 nm \\ \hline \hline \end{tabular}
\end{table}
Table 3: Comparison for PI.  
Figure 22: (**a**) PLL output clock when using traditional PI, (**b**) PLL output clock when using improved PI.  
At temperature 125 \({}^{\circ}\)C and tt corner, the power consumption of the receiver is measured to be 0.44 pJ/b (the overall system power consumption is 1.56 pJ/b). Figure 24 shows that the VCO outputs eight-phase clocks of equal phase, each with a phase difference of 15.6 ps and a 2.4 ps jitter.  
Figure 25 shows the bathtub curves of L0 to L15. The eye opening is 15.02 ps in L0 to L7 in Figure 25a and 14.98 ps in L8 to L15 in Figure 25b. With a channel loss of 10 dB and a channel length of 50 mm, the worst eye opening is opened at 15.02 ps at 10\({}^{-15}\).  
Table 4 shows the performance of the previous work compared to this one. There is a decrease in power consumption when adopting the same signal-DS [19; 20]. This work is highlighted by the bidirectional bandwidth density of up to 284 Gb/s/mm compared to SES transmission [8; 21]. As The BER is less than 10\({}^{-15}\) and the channel loss is 10 dB, it can support standard packaging D2D interconnects of 512G.  
Figure 24: Eight equal phase clocks.  
Figure 25: Measured bathtub diagrams showing the eye opening at 10\({}^{-15}\). (**a**) bathtub curves of L0 to L7, (**b**) bathtub curves of L8 to L15.
## 4 Assessment
### Radio Environment Modem Analysis  
Once KQI performance ranges have been identified for various services, it becomes necessary to illustrate the conditions of the radio environment in which they have taken place. For this purpose, a MODEM Log data collection of 10 days without events (Normal day) has been performed to compare with the data collected in campaigns 1 and 2.  
Thus, Figure 9 shows in the form of an hourly boxplot the RSRP values over an entire day, the upper part corresponding to a \"normal\" day and the lower part to the events. Likewise, Figure 10 shows the values corresponding to RSRQ.  
It is possible to visualize if there is a consistency across matches compared to the behavior of a \"normal\" (without event) day. By observing the time series of relevant radio parameters, a clear difference in each operator's behavior in relation to the course of a match can be noticed. Here the operator A can be seen to drop from an average RSRP of around \(-80\) dBm in normal conditions to values below from 16:00 on match days. On the other hand, the RSRQ values, which for operator B remain above \(-10\) dB in normal conditions, are significantly lower in the afternoon at both nodes. Lastly, it is evident that the graph concerning the parameters obtained on a \"normal\" day shows a pattern with less variability compared to match days.
# A Sub-6 GHz MIMO Antenna Array for 5G Wireless Terminals
## 5 Conclusions  
In this paper, a circular-shaped antenna is demonstrated with an inner circular slot, plus a rectangular slot at the right edge of it to make the proposed design resonate at the 5.57 GHz dedicated for Sub-6 GHz 5G communication applications. To achieve a desired gain, four-element array configuration is adopted which improves a bore side gain to 12.4 dB from 6.66 dB. Then, the two-port configuration is adopted such that the isolation achieved between them is more than \(-\)30 dB. The total efficiency of the proposed antenna array is observed to be more than 80% within the operating bandwidth, and the measured results of the proposed array are in good agreement with the simulated ones. Moreover, the SAR analysis is also presented for the proposed MIMO configuration; obeying the standard value of \(<\)2 W/kg for any 10 g of tissue. Thus, the proposed design becomes a potential candidate for 5G mobile phones and handheld devices. In the future, the MIMO antenna will be fabricated and tested to validate the results, and will be further extended utilizing the metamaterials concept.  
Conceptualization, S.U.; methodology, J.K.; software, J.K. and F.A.T.; validation, F.A.T. and J.K.; formal analysis, F.T.; investigation, J.K.; resources, S.U.; writing--original draft preparation, J.K. and F.A.T.; writing--review and editing, S.U., F.T. and R.R.; visualization, F.T.; supervision, S.U.; project administration, S.U.; funding acquisition, R.R. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
The authors declare no conflict of interest.
# Energy-Efficient Resource and Power Allocation for Underlay Multicast Device-to-Device Transmission
## 1 Introduction  
With the emergence and popularity of the Internet of Things (IoT) [1; 2], billions of devices will be connected and serviced by current wireless networks. In particular, the local area service of popular content sharing is one of the main reasons for this tremendous growth. Such unprecedented growth of data has brought great pressure to current network architectures and technologies. Under this circumstance, the direct connectivity between mobile devices, namely, Device-to-Device (D2D) communication underlay cellular networks, emerges as a potential component for the fifth generation (5G) mobile networks [3].  
The concept of underlay D2D multicast transmission refers to the high spectrum-efficient D2D multicast transmission scenario (from the cluster head (CH) to multiple member user equipment (UEs)) which reuses the resource of existing cellular links [4]. By exploiting the inherent broadcast nature of wireless channels, D2D multicast transmission provides an effective solution to offload the heavy data traffic to D2D links, which not only mitigates the burden of the base station (BS) but also increases the spectrum efficiency of the network [5]. Concerning with current researches about D2D multicast transmission, most works mainly focus on utilizing D2D multicast to improve the system spectrum efficiency, or to provide offloading function while the energy efficiency of D2D multicast transmission has often been omitted [6; 7; 8; 9; 10; 11]. In this paper, based on the existing contributions, we propose an energy-efficient resource allocation and power control strategy for D2D multicast transmission scenario. Specifically, in order to maximize the overall energy-efficiency of D2D multicast clusters, we first formulate the energy-efficiency optimization problem which is a non-convex problem. Then, we propose a heuristic resource allocation and power control algorithm, which brings computational complexity compared with the conventional exhaustive searching based algorithms. The proposed scheme has better performance with respect to energy-efficiency.  
The rest of the paper is organized as follows. In Section 3, we formulate the network model and illustrate the energy-efficiency maximization problem. Section 4 investigates the resource and power allocation problem with energy-efficient consideration and a heuristic algorithm is then proposed. Simulation results and analysis are given in Section 5. Finally, Section 6 concludes the paper.
## 1 Introduction
The method was validated using experimental measurements of various EPU setups. The parameter identification procedure is presented which, based on experimental measurements data or manufacturer's data, results in EPU static maps. Such static maps exactly show the physical parameters in relation to the control (PWM) signal and characterize EPU. The characteristics show aerodynamic forces and moments with respect to rotor angular velocity as well as energy consumption and overall efficiency measure. The proposed characterization method without significant modifications can be applied to the full power range of EPUs, from a few watts to a few tenths of kilowatts which can further lead to parameter estimation, system analysis, and optimization. The paper is organized as follows. Section 2 describes multirotor UAV system. The EPU parameters identification procedure and propulsion static maps are shown in Section 3. The propulsion characterization and comparison are presented in Section 4. The conclusion follows in Section 5.
## Materials and Methods
### Data and Study Areas
#### 2.1.3 HISDAC-US  
Empirical data on historical urban extents are generally sparse, as remotely sensed data are typically not available prior to the 1970s. However, novel data sources such as the industry-generated property database ZTMAX (Zillow Transaction and Assessment Dataset [86]), assembled from heterogeneous county-level assessor data, holds the year-built information for large parts of the US building stock and has recently been leveraged to generate the Historical Settlement Data Compilation for the US (HISDAC-US). HISDAC-US is a fine-grained historical settlement database for the under continuous US, composed of gridded surfaces consistently enumerated in a grid of 250 m \(\times\) 250 m, measuring for example, the number of built-up properties per grid cell from 1810 to 2016, which is a proxy measure for building density [9,80] (Figure 4a,b).  
Figure 4: Evaluation data. Historical settlement data compilation for the US (HISDAC-US) built-up properties (BUPR) for (**a**) 1900 and (**b**) 2010, and urban area fractions per grid cell from the history database of the global environment (HYDE 3.2) for (**c**) 1900 and (**d**) 2010, all shown for the Boston metropolitan area.  
Figure 3: Cartographic styles used to depict urban built-up areas in the historical maps used in this study: (**a**) Boston (\(\sim\)1900), (**b**) Atlanta (\(\sim\)1960), (**c**) Birmingham (\(\sim\)1900), (**d**) London (1896), (**e**) Sao Paulo (1906), and (**f**) Lahore (1943).
## 3 A Wiener Process-Based Approach of RUL Prediction with Unequal Interval Data
### Preprocessing of Unequal Interval PCCS Wear Series  
The method of unit time difference coefficient [14] is used to deal with the unequal interval data, to correct the deviation after unequal interval series are converted into equal interval series. The details are as follows.  
The original unequal interval wear series are given:  
\[\Big{\{}Z^{(0)}(\tau_{1}),Z^{(0)}(\tau_{2}),\ldots,Z^{(0)}(\tau_{k})\Big{\}}, \ (k=1,2,\ldots,n) \tag{1}\]  
where \(Z^{(0)}(\tau_{k})=Z(\tau_{k})\), \(\tau_{k}\) is unequal interval mileage point, \(Z(\tau_{k})\) is the wear loss at \(\tau_{k}\).  
The actual mileage interval of the original unequal interval wear series at each monitored mileage point:  
\[\Delta\tau_{k}=\tau_{k}-\tau_{k-1} \tag{2}\]  
The average mileage interval of monitoring mileage points:  
\[\Delta\tau_{0}=\frac{\tau_{n}-\tau_{1}}{n-1} \tag{3}\]  
Equal interval mileage points:  
\[T_{1:k}=\{0,\Delta\tau_{0},2\Delta\tau_{0},\ldots,(k-1)\Delta\tau_{0}\},\ (k=1,2, \ldots,n) \tag{4}\]  
The unit mileage difference coefficients between every mileage segment and average mileage segment:  
\[U(\tau_{k})=\frac{\tau_{k}-(k-1)\Delta\tau_{0}}{\Delta\tau_{0}},\ (k=1,2, \ldots,n) \tag{5}\]  
The total difference of every actual mileage segment:  
\[\Delta x^{(0)}(\tau_{k})=U(\tau_{k})[Z^{(0)}(\tau_{k})-Z^{(0)}(\tau_{k-1})], \ (k=1,2,\ldots,n) \tag{6}\]Equal mileage interval wear series:  
\[X^{(0)}(T_{k})=x^{(0)}(\tau_{k})-\Delta x^{(0)}(\tau_{k}),\;(k=1,2,\ldots,n) \tag{7}\]  
where \(X^{(0)}(T_{k})=X(T_{k})\), \(X(T_{k})\) is the wear loss at equal interval mileage points \(T_{k}\).  
After converting the unequal interval wear series to equal interval series, a linear wear model based on the equal interval wear series can be established.
# Routing Protocols for Mobile Internet of Things (IoT): A Survey on Challenges and Solutions
## 3 Issues Faced by RPL during Mobility
### Issues with Trickle Algorithm  
RPL uses a Trickle timer to control the overhead caused by the DIO messages. The value of this timer is increased if no topological changes are noticed in the network i.e, the network is in a stable state. This makes RPL an energy-efficient algorithm. However, a mobile node may move out of range of the existing parent and leave the DODAG which results in link breakage and packet loss. This issue is only noticed by RPL in the next Trickle period (i.e., 2.3 h [53]) which delays the route repair process. Note that a node has the choice to send a DIS message that enforces other neighboring nodes (already attached to the graph) to send DIO, however, the RPL specifications do not state how and when DIS should be sent [40]. Another issue is that the DIO period of all nodes is exponentially decreased after detecting any inconsistency in the network, which results in a large network overhead.
## 5 Conclusions  
Detecting novel anomalies in networks is necessary to mitigate threats and network violations. For this purpose, we developed the CBC approach, which detects similarity and inter-relation among different anomalies. The IotCIC2023 dataset, encompassing 34 attack types, was employed and converted into two-class and eight-class classification problems. The two-class scenario includes Attack and Benign categories, whereas, the eight-class scenario involves Mirai, Benign, Web, Brute force, DoS, Recon, DDoS, and Spoofing categories. The SelectKBest feature selector selects the top 10 features using the scoring function. The proposed CBC applies k-means clustering to the data, then administers machine learning algorithms on the clusters: XGBoost, AdaBoost, KNN, and Random Forest. The experimental results show that Random Forest achieves the best performance of 0.95 for two-class classification, and KNN attained the highest accuracy of 0.88 for eight-class classification. In summary, the proposed CBC method shows great potential for detecting network attacks and abnormalities. The classification and detection results are promising in finding correlations among different anomalies. A comparative analysis was performed with similar approaches employ clustering for zero-day attacks and novel attacks. The proposed CBC achieves good results; however, its performance cannot be compared fully with that of other methods because each method employs different datasets with distinct parameter tuning. This study significantly contributes to the field of network security by showcasing the potential of the CBC approach to improve the detection of network attacks and abnormalities. It also emphasizes the need for adaptive and accurately tuned detection systems to keep pace with the evolving landscape of network threats, highlighting the importance of ongoing research and development in this critical area of cybersecurity.  
Conceptualization, M.A.N.; Methodology, N.A. and A.A.A.; Software, N.A.; Investigation, A.A.A.; Data curation, N.A. and N.A.A.; Validation, N.A. and A.A.A.; Visualization, A.A.A. and N.A.A.; Writing--original draft, N.A.; Writing--review & editing, A.A.A. and N.A.A.; Supervision, M.A.N. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Data Availability Statement: The data used in this study are publicly available at [[https://www.uwb.ca/cic/datasets/iotdataset-2023.html](https://www.uwb.ca/cic/datasets/iotdataset-2023.html)]([https://www.uwb.ca/cic/datasets/iotdataset-2023.html](https://www.uwb.ca/cic/datasets/iotdataset-2023.html)) (accessed on 4 March 2025).
# PUF and Chaotic Map-Based Authentication Protocol for Underwater Acoustic Networks
## 3 The Proposed Scheme  
Based on the fact that gateways and sensors in underwater acoustic networks are easily captured, the proposed scheme adopted PUF to protect the secret information stored in gateways and sensors. In order to achieve two-factor security, the user's identity and password are verified using fuzzy authentication. To achieve lightweight and secure authentication, the semi-group property of Chebyshev polynomials was adopted to achieve perfect forward secrecy. The notations used in our scheme are listed in Table 1.