esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Application and Results
### CSE Corpus Annotation
#### 4.2.4 Annotator Guidelines  
Two cybersecurity experts with heavy knowledge of the SMEs ecosystem were selected as the annotators and assigned the task to perform annotation at the sub-sentence level. The annotators were also members of the annotation schema development team. They performed a stand-off annotation by character location because, in this case, the metadata type tags are stored separately from the original chat text. This way, we avoided changing the original text format, and reading the original text could be done more efficiently. Most of all, we will be able to deal with overlapping tags if different annotation schemes are to be merged in the future.  
Over twenty different annotation tools (open source and commercial) were tested during the annotation project. We decided to use GATE [35] and Prodigy [36] due to their completeness and capability of building complete natural language pipelines of NLP tools.  
Annotators were given guidelines to direct them about tagging the important terms in a compliant way based on our schema. Several examples were also given to help resolve ambiguous term cases. First, the different tags were explained, and prioritisation guidelines were given for the case of an ambiguous term that could belong in more than one category. For example, if an outsider asks for the (First or Last) Name of a department's supervisor, the answer can be tagged by Personal and Enterprise tag simultaneously. Annotators were advised to follow this order:  
1. prefer IT category over (Enterprise category or Personal category)
2. prefer Enterprise category over Personal category  
This priority order ensures that IT details have greater importance over all other categories, and Enterprise details have greater importance over Personal details.  
More specifically, an excerpt from the annotators guidelines follows:  
1. Each text span may be tagged with _Personal_, _IT_ or _Enterprise_ main tags
2. If a sentence has entities that can fit in two or more tags, then follow the following priority IT > Enterprise > Personal
3. Prefer individual words to word combinations
4. The tag _Personal_ is assigned to whatever information is related to a person. e.g., first name, Last Name. Consult CSE ontology
5. The tag _IT_ is assigned to whatever information is related to Information Technology, e.g., USB stick, computer, software and others. Consult Ontology
6. The tag _Enterprise_ is assigned to whatever information is related to enterprises and enterprise environment, e.g., Department, office, positions, resumes and others. Consult CSE ontology
7. A sentence can have no important words. This sentence is call Neutral
8. Noun-verb combinations and verb repetitions will be identified automatically based on blacklists  
Table 3 lists a sample of the examples that were given to the annotators where the important terms are in italics, and the tags assigned to each one of them is on the right column.
## 3 Methods  
Our data assimilation methodology included an EnKF which recursively updated the albedo by coupling the direct estimation approach with a dynamic model. A flow chart of this process is shown in Figure 2. The existing high quality multi-year MODIS albedo product data is averaged to compute albedo climatology, then a simple dynamic model is established based on the climatology to evolve albedo over time and to forecast short-range albedos. A direct estimation approach is used to generate high-resolution TM albedo data. The EnKF technique is used to estimate real-time albedos by combining the predictions from the dynamic model and the high-resolution TM data.  
The proposed method was essentially a three-step process:  
(1) Obtain MODIS albedo data for the historical period of interest, correct them geometrically, convert black-sky albedo (BSA) and white-sky albedo (WSA) to blue-sky albedo using the scatter ratio, resample to a 30 m resolution, and average the albedo of the historical period to obtain the time-series shortwave albedo climatology;  
(2) Transform the cloudless TM image into a 30 m spatial resolution TM shortwave albedo via direct estimation algorithm; and  
(3) Use the EnKF method with the MODIS time series albedo as the background field and input the TM high spatial resolution albedo data to estimate the high spatial resolution albedo.  
This method effectively integrated the time change information from MODIS data and spatial Landsat data to resolve issues with the low spatial resolution, sparsity, and long return cycle of MODIS data, as well as the sparsity of Landsat data to ultimately obtain high spatial and temporal resolution albedo data.
## 2 Setup and Methods
### FDDA Refinement
In our case, the mode of the spectrum signal level indicates one of the most frequently occurring values of a signal level in it. Limiting \(w_{\text{max}}\) to the length of the original data sample still did not eliminate the spectrum distortion caused by taking into account large values of the useful signal when the window moves over a noise region far from them (Figure 5a). An experiment regarding iterating over different \(w_{\text{max}}\) values when processing the same spectra at constant \(s_{t}\) led to the conclusion that \(w_{\text{max}}\) should be approximately equal to the local bandwidth of the useful signal (Figure 5b). In this case, acceptable noise suppression was achieved, and the maximum (middle) of the \"pedestal\" fell in the middle of the useful signal band. In this work, we applied the algorithm sequentially to the frequency and to the spatial domain (to the frequency and spatial cross sections in Figure 2). Since the method had  
Figure 5: Original and AFDA-processed spectra at different \(w_{\text{max}}\), \(s_{t}\) = 0.5; (a) \(w_{\text{max}}\) = 500; (b) \(w_{\text{max}}\) = 100 counts. (c) Original and FDDA-processed spectrum at \(w_{\text{max}}\) = 10,000 counts. 2 variable (\(w_{\max}\), \(s_{t}\)) and 1 estimated (SNR) parameter, it was decided to search for the optimal values for two types of the useful signal cross sections using heatmaps (Figure 6a,b). The optimal value of \(w_{\max}\) for the cross section 6c (Figure 6c) was 98 counts, and \(s_{t}\) was 0.51. For cross section 6d (Figure 6d), these values were 180 counts and 0.85, respectively. The obtained results allowed us to draw conclusions not only regarding the existence similarity of optimal values for similar ratios of amplitudes and the local signal bandwidth in the spatial or frequency domain, but also regarding the validity of the previous assumptions. Thus, the useful signal bandwidth in the frequency domain was about 100 rel. units, and in the spatial, about 200. The calculated optimal \(w_{\max}\) values turned out to be approximately equal. Therefore, when processing the 2D data (acoustic spectrum distribution over space, Figure 2, for instance) with AFDA, firstly, all of the frequency-domain cross sections were processed with \(w_{\max}\) = 100 rel. units, and the spatial ones with \(w_{\max}\) = 200 rel. units. It also has been noticed that it is this sequence that results in a slightly better SNR than the opposite.
# BGPcoin: Blockchain-Based Internet Number Resource Authority and BGP Security Solution
### Contribution  
For the inherently error-prone and unsecure Internet, the blockchain is an outstanding candidate for reliable and trustworthy infrastructure [26], supporting security architectures [25; 27]. We propose BGPcoin, a blockchain-based Internet number resource authority and trustworthy management solution that meets all the above security and functional requirements. BGPcoin maintains a set of smart contracts to compel every involved authority to operate the compliant Internet number resource transaction (including resource assignments and revocations under the consents). Therefore, BGPcoin primarily excludes the entity misbehaviors and misconfigurations that violate the contract. It records resource assignments and authorizations in an append-only and tamper-resistant way on the decentralized blockchain infrastructure where reversing and overwriting the resource transactions is forbidden. As a result, BGPcoin maintains a consistent view of information to avoid a mirror world attack like in RPKI. Moreover, BGPcoin requires neither online cryptography during routing, nor any modification to the BGP message formats. By tracing the usufructs of resource assets, which are changing continuously, the BGP routers match the source in origin advertisements, then detect and discard prefix hijacks. The natural financial incentives of the permission blockchain like Ethereum and the transaction framework for all parties involved provide an easy way to deploy the solution. Our contributions are as follows:  
* We design BGPcoin, a blockchain-based Internet number resource management system, which contributes not only a tamper-resilience and transparent Internet routing registry, but also an origin repository and governance infrastructure for BGP security.
* We propose a lightweight and efficient origin authentication framework around the blockchain for BGP security, which has superior security resilience and is more easy and lightweight to deploy than the PKI-based origin attestation solutions.
* We implement a prototype in Ethereum, deploying it not only on a private blockchain, but also on an official Ethereum testnet. We evaluate the performance and scalability of BGPcoin in practice, and the result demonstrates that it has very reasonable computational requirements.
# Can We Improve Parametric Cyclonic Wind Fields Using Recent Satellite Remote Sensing Data?
###### Abstract
To this aim, we first check whether using CYGNSS and/or ASCAT data as wind speed proxies enable reproduction of the strengths and weaknesses of various parametric models reported by previous studies (Section 4). The performance of a few parametric formulas is then tested in the case of hurricane Maria (2017), for which numerical hindcasts are performed (Section 5). Finally, we discuss the main results of the manuscript and give concluding remarks (Section 6).
## 3 Analysis of Monitoring Results
### Stress Analysis of Supporting Structure at Different Temperatures
#### 3.2.2 Stress Analysis of Retaining Piles at Different Temperatures  
A total of 18 strain gauges were arranged on each retaining pile every 0.5 m, and the top strain gauge was shifted down by 0.2 m due to the reserved hoisting hole at the pile crown. The measuring points on retaining pile 1, retaining pile 2, and retaining pile 3 were indicated by A1-A18, B1-B18, and C1-C18, respectively, as shown in Figure 12. The measured data were analyzed, and the stress-temperature relationship curves of retaining piles 1, 2, and 3 are drawn in Figure 13a-c, respectively.  
Figure 11: A schematic diagram of a 45\({}^{\circ}\) rectangular strain rosette.  
It can be seen in Figure 13 that after the excavation of the foundation pit was completed, the retaining pile deformed to the pit. Due to the maximum displacement at the crown of retaining pile 3 and the minimum displacement at the crown of retaining pile 1, the stress on point C1 was the minimum, while that on point A1 was the maximum. The maximum stress occurred on the excavation face, and B13 \(>\) C13 \(>\) A13.  
When the temperature rose from 10 to 25 \({}^{\circ}\)C, higher thermal stress was released due to the large displacement of the pile crown. The stress on points A1, B1, and C1 increased by 2.68, 2.30, and 1.44 MPa, respectively, but the stress basically did not change. However, the pile bottom was embedded in the soil, and there was almost no displacement; thus, it was easier for the pile bottom to accumulate stress. The stress on points A18, B18, and C18 enlarged by 5.47, 13.81, and 6.00 MPa, respectively, which was even greater than the increment in stress caused by the excavation of the foundation pit. The stress on the  
Figure 12: The layout of the strain gauges installed on the retaining piles.  
Figure 13: The stress–temperature relationship of (**a**) pile 1, (**b**) pile 2, and (**c**) pile 3.  
other measuring points also increased with the temperature rise, which was obviously unfavorable for the stress on the retaining piles.  
Due to the corner effect, the stress on point A13 of pile 1 increased by 8.02 MPa after the temperature rose by 15 \({}^{\circ}\)C. Its increase amplitude even exceeded the stress on the bottom of the pile, which was obviously different from the variation law of the corresponding positions of piles 2 and 3. The stress curves of piles 2 and 3 were similar, but the stress on pile 2 was greater than that on pile 3. Under the excavation and temperature load, the stresses on piles 2 and 3 was finally 69.95 and 43.89 MPa, respectively, both of which fulfilled the allowable stress on steel.
## 3 Design Challenges of MAC Protocol for IBSN
### Types of Access Mechanisms Recommended for IBSN
#### 3.2.1 Time Division Multiple Access (TDMA)  
The scheduled access mechanism of the physical medium is carried out either by scheduling the content or carrier. In TDMA-based approaches, scheduled access is carried out by synchronizing all nodes in the network to a specific time-frame and allocating a scheduled time slot for each sensor node. The advantage of this method is enabling collision-free communication due to time schedules being set up. This will reduce the power consumption and increase the throughput of the network. However, the time schedule needs an accurate time synchronization between the nodes. A deviation in the synchronization will cause the network to operate less efficiently or sometimes even fail to operate. TDMA is considered to be a suitable candidate for the IBSN for the following reasons:  
* Time synchronization is less complex due to the smaller size of the IBSN compared to other WSN applications.
* The star topology is preferred for IBSN where a central network controller (CNC) is always present outside the body in close proximity of the network. This enables simpler coordination between the nodes.
* Collision avoidance is easier with low power consumption.
# Earthquake Magnitude and Frequency Forecasting in Northeastern Algeria using Time Series Analysis
###### Abstract  
This study uses two different time series forecasting approaches (parametric and non-parametric) to assess a frequency and magnitude forecasting of earthquakes above Mw 4.0 in Northeastern Algeria. The Autoregressive Integrated Moving Average (ARIMA) model encompasses the parametric approach, while the non-parametric method employs the Singular Spectrum Analysis (SSA) approach. The ARIMA and SSA models were then used to train and forecast the annual number of earthquakes and annual maximum magnitude events occurring in Northeastern Algeria between 1910 and 2019, including 287 main events larger than Mw 4.0. The SSA method is used as a forecasting algorithm in this case, and the results are compared to those obtained by the ARIMA model. Based on the root mean square error (RMSE) criterion, the SSA forecasting model appears to be more appropriate than the ARIMA model. The consistency between the observation and the forecast is analyzed using a statistical test in terms of the total number of events, denoted as N-test. As a result, the findings indicate that the annual maximum magnitude in Northeastern Algeria between 2020 and 2030 will range from Mw 4.8 to Mw 5.1, while between four and six events with a magnitude of at least Mw 4.0 will occur annually.  
earthquake magnitude forecasting; time series analysis; singular spectrum analysis (SSA); autoregressive integrated moving average (ARIMA) model +
Footnote †: journal: Applied Sciences  
2023 by the authors. Liconse MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/)]([https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/))).
## 4 Methodology
### TLF Prediction Component
Considering the size of the dataset and the complexity of the models, time requirements for a single training loop with fixed hyper-parameters were not a critical issue. However, hyper-parameter optimization over a broad search space by means of an exhaustive search was infeasible. For that, we followed a two-step approach for hyper-parameter optimization: (1) a low-resolution, low-cost random search over the search space which identified the approximate optimum regions, and (2) an exhaustive grid search limited to the identified regions.
###### Abstract
Similarly, [PERSON] et al. [21] conducted a field experiment in a gold tailings pond and showed that the revegetation could effectively reduce the metal(loid) content in the rhizosphere and enhance the nutrients. Beyond short-term revegetation studies, several researchers have focused on the effects of revegetation on the chemical behavior of metal(loid)s. For example, [PERSON] et al. [22] analyzed depth profile samples from Pb-Zn tailings at different revegetation times (0-8 years) and showed that revegetation can drive the transformation of Sb and As from the reduced state (Sb\({}^{3+}\) and As\({}^{3+}\)) to the oxidized state (Sb\({}^{5+}\) and As\({}^{5+}\)), which provides valuable insights into understanding the geochemical behavior of the metal(loid)s under revegetation. However, the systematic effects of revegetation in large-scale antimony mining areas are still lacking, particularly regarding comprehensive monitoring of metal(loid) migration behavior, bioavailability changes, and ecological risk evolution. In addition, existing ecological risk assessment methods for mining areas, such as the geo-accumulation index method and the potential ecological risk assessment method, all focus on the total content of metal(loid)s [9; 23]. It should be noted that only the bioavailable fraction of metal(loid)s has a strong mobility and can be easily absorbed by organisms. Therefore, only using the total content as an indicator may exaggerate the actual risk level, which may lead to an unnecessary increase in the management cost [24; 25; 26]. Therefore, it is critically needed to conduct the multidimensional monitoring and comprehensive assessment of the revegetation effects in antimony mining areas, which will fill existing research gaps and inform environmental management strategies for these regions. Thus, the XKS antimony mine in Hunan Province, which is the largest antimony mine in the world and known as the \"antimony capital\" [27], was selected as a typical research area for this study. Through a systematic comparison of geochemical parameters, total metal(loid) content, speciation distribution, and the comprehensive risk between the unremediated waste piles and the revegetated restored area. This study aimed to (1) reveal the effects of revegetation on the geochemical parameters of the antimony mine area, (2) investigate whether revegetation could stably and persistently reduce the total content of metal(loid)s and change their chemical patterns, and (3) assess whether the comprehensive risk level of the antimony mine waste dump area has been reduced to a controllable level after the revegetation. The results of this study provide a theoretical basis for the scientific evaluation of the ecological effect of antimony mine revegetation and guidance for the subsequent management of mine waste and ecological risk control.
## 5 Case Studies on the OMF-Enabled Testbed
### Case Study 2: Available Bandwidth Estimations
Differently from the previous experiment, where the true avail-bw has been obtained using the MRTG data, the reference value in this experiment scenario is approximated by the throughput of a single constant bitrate (CBR) UDP flow with a packet size of 1500 Byte. When the wireless channel is idle, the measured ground truth throughput shows the avail-bw of appr. 17.40 Mbps. The achieved results are illustrated in Figure 4(b). In the ideal case, where no cross-traffic is available in the shared medium, wbest and pathchirp yield acceptable estimation errors of 1.26% and 2.87%, respectively, i.e., the produced avail-bw estimates are close to the ground truth. In lowly congested scenario, wbest and pathchirp yield estimation errors of 3.75% and 6.45%, respectively. In moderately congested scenario, the observed estimation errors of wbest and pathchirp increase to 6.84% and 13.50%, respectively. Finally, in a heavily congested scenario, both tools exhibit a very high variance in estimating the avail-bw and yield highly unreliable estimates (i.e., the produced estimates reach errors of up to 33.21%). The high discrepancies between ground truth and active tool estimates are mainly caused by the fact that both active tools are based on sending carefully scheduled successive  
Figure 5: Validation of end-to-end avail-bw estimation tools. probe packets which are distorted by cross-traffic simultaneously passing the same shared medium. Particularly, in contrast to wired single-access networks, where the duration for transmitting the packet from the application layer onto the link can be approximated with a constant time, the lower layer of 802.11 networks can induce nondeterministic time jitters between successive probe packets due to shared medium and multiple access characteristics. The detrimental effects of cross-traffic on wbest's and pathchirp's estimation accuracies become more apparent for heavily congested network scenarios. When compared with pathchirp, wbest could relatively closely approximate the avail-bw. In general, it is seen that pathchirp consistently overestimates the avail-bw with a large variance whereas wbest underestimates the avail-bw, especially as the rate of generated cross-traffic increases in the shared medium.
# Real-Time Wave Energy Converter Control Using Instantaneous Frequency
## 4 WEC Control Using Estimated Instantaneous Frequency
### Fixed Parameter PTO Control
#### 4.5.1 Description of Estimation Methods and Control Scheme  
There are four frequency estimation methods utilized:  
* Fixed Parameter Control: No real-time frequency estimation is used. The PTO damping is tuned to a fixed value based on the dominant wave period.
* Phase Locked Loop (PLL)-Based Estimation: The instantaneous frequency is estimated using a PLL, which tracks phase variations to determine frequency changes dynamically.
* Causal Hilbert Transform (CHT): The CHT is applied within a short time window, providing an approximation of the instantaneous frequency using past wave data.
* Non-Causal Hilbert Transform (NCHT): The Hilbert transform is applied with full access to both past and future wave signals.  
In reference to Section 4.1 and Equations (16) and (17), the control applied is simple proportional damping PTO control, in which the damping is calculated and applied at each real-time sample time in accordance with one of the frequency estimation methods described above.