esa-sceva/satcom-chunk-collection huggingface dataset:
# Mail Man Ferry: A Novel Routing Protocol in Intermittently Connected Networks
## 2 Motivation and Contribution  
ICNs create routing challenges, because commonly used routing protocols may not be applicable in such a structure for delivering data. Thus, ICN networks have several issues that are less likely in legacy networks. These issues include network partitioning, high loss probability, long and varying delays, asymmetric data transmission rates [3], and detecting and preventing intrusion of malicious nodes [4]. Further, nodes in ICNs have limited buffer space and battery life; this could affect their cooperation in carrying messages from other nodes because frequent retransmission leads to occupying their buffer space as well as energy consumption. The continuous exchange of messages also leads to other messages being dropped due to the limited buffer space [5]. The characteristics of ICNs have made it difficult to find an approach that has a high probability of delivery while maintaining energy efficiency. This signifies the importance of utilizing the resources effectively and efficiently. This can be achieved by enhancing the cooperation between nodes.  
A node is considered to be cooperating with other nodes when it accepts the responsibility of carrying messages sent by other nodes. Pdrop is the chance that a node drops a message after receiving it, and Pforward is the probability that the messages is forwarded. These probabilities are affected based on node misbehavior or node buffer or energy limitation [6], which influences node cooperation. A similar experiment was carried out in [7]; however, this time, Pforward was used in its place as a dynamic parameter. The assumption in [8] was that a node does not discard a message after receiving it, although an encountered node may not accept it. These studies show the impact of node cooperation in an ICN in which they confirmed that noncooperating nodes sharply decrease the delivery probability in an ICN. Thus, a need for the work in this paper is raised where a routing protocol for ICNs with a node cooperation mechanism is ensured.  
In this paper, we propose a novel protocol, Mail Man Ferry, that improves the delivery probability by improving the routing decisions. It includes a node credit mechanism to ensure an informative decision is made as to whether the message is forwarded. Node credits increase by the number of times a node travels through a ferry path to help other nodes deliver their messages.
# Palmprint False Acceptance Attack with a Generative Adversarial Network (GAN)
## 3 Methodology and Evaluation
### Image Generation  
We selected DCGAN to generate the fake palmprint images used for FAA because of the following advantages:  
* DCGAN is stable in training in most cases, so it is suitable for palmprint image generation if the number of the palmprint training images is not very large. In addition, the batch normalization in DCGAN can effectively suppress overfitting and accelerate convergence.
* DCGAN can generate the fake images with high resolution.
* The main hypothesis of this work is that the features (after feature extraction) of fake palmprints, which are generated from the DCGAN, are diverse. This is because if the fake palmprint feature templates are similar (lacking of diversity), then it is difficult for FAA to attack successfully. In other words, the greater the diversity of fake images, the higher the success rate of FAA. This hypothesis is experimentally confirmed by the red curves (imposter fake) in Figure 11. The distances between the fake palmprint templates are large, which demonstrates that the feature templates of the fake palmprint images, which are extracted from the DCGAN, are highly dissimilar; i.e., the diversity in feature domain is high.
* DCGAN employs several techniques for optimization:
* Fully convolutional neural network--strided convolution is used instead of spatial pooling, which allows the network to learn more appropriate spatial downsampling methods.
* Avoidance of the fully connected layer after the convolution layer--although the fully connected layer increases the stability of the model, it also slows the convergence speed.
* Batch normalization is used in all the layers except for the output layer of generator and the input layer of discriminator. Even if the initialization is poor, batch normalization can ensure that the gradients in the network are strong enough.  
Figure 7: Framework of palmprint false acceptance attack with deepconvolutional GAN (DCGAN).  
* Effective activation functions--for the generator, Tanh and ReLu are used as the activation functions of the output layer and other layers, respectively. For the discriminator, leaky ReLU is used as the activation function. The configuration of DCGAN in this paper is shown in Table 3.
###### Abstract  
This study optimized the constants of the RNG k-\(\varepsilon\) model using the Ensemble Kalman Filter (ENKF) data assimilation method to improve the accuracy of air-lift plunger gap flow predictions. For high Reynolds number turbulent flow, we conducted numerical simulations integrating experimental data with a library of predicted data generated via optimal Latin hypercube sampling. ENKF was employed to assimilate these data and adjust the model constants, significantly reducing prediction errors and enhancing the accuracy of plunger models. Specifically, mean square errors for rectangular and circular plungers decreased from 60.67 and 61.48 to 7.12 and 7.20, respectively. The study also revealed significant changes in vortex dynamics and flow distribution following data assimilation, providing insights for optimizing plunger design and improving system energy efficiency. These findings underscore the potential of data assimilation in advancing oil and gas production.  
Ensemble Kalman Filter; data assimilation; air-lift plunger; flow characteristics; predictive accuracy +
Footnote †: journal: Applied sciences
# Named Entity Recognition Method Based on Multi-Feature Fusion
## 1 Introduction
This approach incorporates multi-feature extraction and a dynamic fusion method leveraging a multi-head attention mechanism, augmenting the traditional feature extraction and fusion process. A framework tailored for Chinese NER in online reviews is constructed to optimize the entity extraction process, mitigate potential issues of critical feature loss and gradient vanishing and enhance both the precision and accuracy of the entity recognition task. This model provides a robust foundation for subsequent downstream tasks. The main contributions of this paper are as follows:  
* When identifying the entity type, the NMF topic clustering method is used, and the entity type is confirmed according to the clustered topics and feature words. Using the original text as background information, and the topic clustering method can make the model better identify the key information in the online text, and improve the accuracy and scientific rigor of the entity extraction task. * In feature extraction, BiLSTM is integrated with DGCNN to extract features effectively. On one hand, BiLSTM leverages bidirectional mechanisms to efficiently capture contextual information, enhancing the model's capability to represent temporal features. On the other hand, DGCNN, with residual connections and gating mechanisms, employs dilated convolutions to capture more spatial features with fewer layers while mitigating overfitting and vanishing gradient issues. * During feature fusion, the Multi-head Attention Mechanism (MHA) was used to dynamically fuse the features extracted by the model. Through multiple attention heads, the model can capture more diverse features at different levels, scales and semantic levels, thereby improving the generalization ability and robustness of the model. The rest of this paper is organized as follows. Section 2 introduces related research work. Section 3 introduces the experimental design, including the overall framework of this study and the methods adopted in each part. Section 4 presents the experimental procedures and results. Section 5 discusses the experimental results, and finally, Section 6 concludes this paper.
## 4 Results  
### Statistical Analysis of Eye-Movement Data  
#### 4.1.1 Analysis of Differences in Eye-Movement Indicators in Different Types of Public Spaces  
We collected the study data and organized them. According to the data, the mean values of the subject's eye-movement indexes for different public spaces differed. We tabulated the selected indexes of the average fixation duration, fixation count, saccade amplitude, and saccade count according to the different mean values (Table 2) to facilitate further analysis. Average fixation duration analysis: The average gaze durations of the four types of public spaces fluctuated between 0.28 s and 0.38 s (Figure 2(a)). The descending order is as follows: street space (0.41 s); waterfront space (0.40 s); public green space (0.38 s); square space (0.28 s). The longer the gaze duration, the more information is acquired by the subject when perceiving the spatial environment and scene with more effort. According to the experimental data, the subjects needed to find more gaze points to observe the street space, and they paid less attention to the square space. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Public-Space**} & \multicolumn{2}{c}{**Average Fixation**} & \multicolumn{2}{c}{**Fixation Count**} & \multicolumn{2}{c}{**Average Saccade**} & \multirow{2}{*}{**Saccade Count**} & \multirow{2}{*}{**Total Observation**} \\ \cline{2-2} \cline{5-8}
**Category** & & & & & & & & **Time (s)** \\ \hline Square space & 0.28 & 0.06 & 75 & 15.89 & 123.91 & 24.78 & 74 & 15.89 & 30 \\ Street space & 0.41 & 0.10 & 62 & 17.06 & 132.29 & 42.50 & 61 & 17.06 & 30 \\ Waterfront space & 0.40 & 0.03 & 84 & 16.82 & 152.95 & 41.89 & 83 & 16.77 & 30 \\ Public green space & 0.38 & 0.11 & 91 & 22.85 & 179.66 & 18.55 & 90 & 22.85 & 30 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Mean values of eye-movement indicators in different types of public spaces.
# An Adversarial DBN-LSTM Method for Detecting and Defending against DDoS Attacks in SDN Environments
## 4 Experimental Results and Discussion
### Evaluating Indicator  
To better compare the performance with similar papers, we adopt four traditional indicators: _Accuracy_ (A), _Precision_ (P), _Recall_ (R), and \(F1\) Score (F1). The A represents the probability of the IP flow records being correctly identified. The P represents the percentage of actual DDoS attacks in determined DDoS attacks. The R represents the percentage of DDoS attacks detected in all DDoS attacks. As for F1, it is the harmonic between R and P. Their specific formula is defined as follows:  
\[Accuracy=\frac{TP+TN}{TP+FP+TP+FN}\]  
\[Precision=\frac{TP}{TP+FP}\]  
\[Recall=\frac{TP}{TP+FN}\]  
\[F1=2\times\frac{Precision\times Recall}{Precision+Recall}\]_TP_ means True Positive. _TN_ represents True Negative. _FP_ means False Positive. Moreover, _FN_ means False Negative.
## 3 Results and Discussion
### Optimization Parameter for the Synthesis of Carbon Dots (CDs)
#### 3.3.2 Effect of Temperature of Synthesis on CDs  
The effect of different temperatures on the synthesized N-doped CDs and the fluorescence properties shows that the produced CDs' intensity increases with increasing temperature of the synthesis [75]. Figure 4e shows the fluorescence intensity profile of the effect of temperature on the synthesized CDs-EDA. The fluorescence intensities showed incremental gradation with an increase in temperature from 120-200 \({}^{\circ}\)C with the highest synthesis temperature of 200 \({}^{\circ}\)C, delivering the highest fluorescence intensity. In Figure 4f,  
Figure 4: PL emission spectra of (**a**) CDs-EDA (**b**) CDs-L-Ph, at an excitation wavelength range of 350–400 nm; (**c**) effect of Volume of EDA on Emission spectra of CDs-EDA (**d**) effect of Mass of L-Ph on Emission spectra of CDs-L-Ph; (**e**) effect of temperature on the emission spectra of (**e**) CDs-EDA (**f**) CDs-L-Ph. Effect of dilution on the emission spectra of (**g**) CDs-EDA (**h**) CDs-L-Ph.  
the effect of temperature on CDs-L-Ph's fluorescence intensity was displayed. By varying temperature from 120-200 \({}^{\circ}\)C, the CDs showed increasing fluorescence intensity with a peak centred in the range of 420-450 nm. The maximum fluorescence peak obtained at 200 \({}^{\circ}\)C using an excitation wavelength of 360 nm. However, the fluorescence peak produced at 160 \({}^{\circ}\)C and 360 nm excitation wavelength appeared more stable for the two CDs. The fluorescence peaks become unstable above 160 \({}^{\circ}\)C, which may be due more to the high degree of carbonization than the degree of surface functionalization. The process leads to an irregular and narrow fluorescence peak [75]. Thus, the temperature of 160 \({}^{\circ}\)C was chosen for the CDs synthesis for stable and appreciably better fluorescence peaks produced at that temperature.
# A GPS Phase-Locked Loop Performance Metric Based on the Phase Discriminator Output
## 8 Tracking Error as a Design Metric
### PLL Performance Metric Based on Tracking Error  
The general form of the proposed tracking error performance metric is,  
\[k\sigma_{e}+\epsilon_{D}\leq R \tag{45}\]  
where \(k\) is an inflation factor, \(\epsilon_{D}\) is worst case dynamic stress (from all sources), and \(R\) is the discriminator pull-in region (90 degrees for the arctangent discriminator). The dynamic stresses can be accounted for in the same way as in the phase jitter metric. The worst case tracking error can be approximated by the steady state value of tracking error due to a particular stressor. Practical values of the inflation factor will be, \(k\geq 2\).  
For example, with \(k=2\) and no dynamic stress, the metric becomes \(\sigma_{e}\leq 45\) degrees. In other words, two-sigma tracking error must not exceed the discriminator's pull-in region. The tracking error distribution for this case roughly corresponds to the 25.5 dB-Hz curve in Figure 12. The distribution is approaching a uniform distribution, so the mean-time to cycle slip (MTCS) is likely not very long. This case can be used as a quick feasibility check when designing PLLs. In practice, \(k\) should be inflated to reduce the maximum tolerable tracking error standard deviation. This will yield a more significant MTCS by ensuring that the tracking error distribution does not become uniform.  
The results in this section have validated the augmented linear model (developed in Section 3) using simulation up until a 52 degree standard deviation of tracking error, \(\sigma_{e}\). This threshold was shown to be significant in that it is representative of the tracking error distribution being uniformly distributed over the discriminator's pull-in region. The tracking error PLL performance metric was defined to guarantee the tracking error distribution does not approach a uniform distribution.  
The standard deviation of tracking error, \(\sigma_{e}\), has the potential to be much more reliable as a PLL design metric than the phase jitter metric, \(\sigma_{PLL}\) (which is equivalent to \(\sigma_{\phi}\) for the AWGN only case). However, in a realistic scenario, the reference oscillator phase-noise will impact the tracking error and must also be accurately modeled.
# A Systematic Literature Review on Military Software Defined Networks
## 7 Discussion and Recommendations for Future Work
### Control Systems  
The traditional SDN architecture requires a node to contact the centralized SDN controller whenever it encounters a new request in which it needs to make a decision for a data plane operation, and for which it does not have the required control plane information. However, this centralized architecture is not suitable for military tactical networks with high levels of dynamism and frequent network failures that can result in slow network updates as well as significant controller overhead. The areas for further exploration include, but are not limited to:  
* Investigating SDN controller fail-over mechanisms to automatically take the control of the switches when a neighbour controller fails.
* Describing a distributed SDN controller network architecture that can meet reliability requirements through the use of multiple remote SDN controllers with integrated redundancy features.
* Exploring Software Defined Coalitions (SDCs) which share assets at increasing granularity, allowing a better sharing of the network, storage and application level services available in each of the partners.
* Identifying the required and appropriate abstractions which should be exposed to the partners, in respect to the policies of the coalition members.
* Creating the right interfaces for OODA (Observe, Orient, Decide and Act) based control of individual elements.
* Developing appropriate routing, security, information and asset sharing mechanisms for coalition operations.
* Optimizing the policy constructs for coalition missions.  
* Defining the interaction between controllers of different nations across interoperability points of a Protected Core (PCore).
* Developing approaches to distribute control where necessary--for example, at the level of individual network functions such as mobility--without sacrificing the benefits of programmability that come from centralization in other areas.
* Examining fault types beyond SDN controller faults, e.g., attacks that aim to exhaust resources in typical SDN switches, with resulting delays in the packet forwarding.
* Recovering from faults using SDN. It is interesting to study whether and how SDN may help speed up recovery from faults in a communication network that supports tactical military networks.
# On the Control of Low-Frequency Audible Noise from Electrical Substations: A Case Study
## 2 Methods
### Noise Propagation Modeling  
The geometric and acoustic data have been given as input to Ramsete, a pyramid-tracing software developed by the University of Parma, Italy, for room acoustics. The program can also be used to model noise propagation outdoors for limited distances between source and receiver (see Section 2.1). A visual rendering of the model before importing it in Ramsete is given in Figure 7.  
Figure 6: Directivity plots for the three frequencies under investigation (averaged over three heights: 1.5 m, 2 m and 3.1 m).  
Figure 7: Three-dimensional representation of the model. Imagery ©2019 Maxar Technologies, Map data ©2019 Google.  
After importing the model in Ramsete, the source and the receivers have been set. Each source has been defined through the sound power spectrum measured in the first experimental session (TR1/TR2) and the average directivity index obtained from the second session (TR3). As concerns the sound absorption characteristics of the involved materials, the only relevant group of trees is located south-west of RPS substation. Considering the relatively small fraction represented by this green area, its distance from the source, the position of the receiver and the position of the substation technical building, it has been concluded that the trees do not significantly modify the sound propagation characteristics, thus the values in Table 1 have been used. The sound absorption of air is considered by Ramsete through a simplified formula as a function of frequency, distance and relative humidity [29].  
A second simulation is performed to calculate the impulse response of the environment at the receiver for auralization purpose. In this case, the actual noise sources are removed and replaced by a white noise source with the same directivity of the transformer, in order to obtain an ideal function that can be \"colored\" with the investigated sound through convolution.
## 5 Conclusions  
A large amount of noise in the MS signal has an adverse effect on the postprocessing of the collected data. A new method combining VMD and AIC is put forward for noise attenuation of MS signals. It can adaptively extract valuable components from the mixed signal by the VMD algorithm, and automatically divide the reconstructed signal into noise and MS segments by adopting the improved AIC method. The results of a synthetic wavelet signal, synthetic MS signals, and noisy field signals illustrate its excellent performance. It can adapt to not only noisy signals with different _SNRs_, but also MS signals with different characteristics. Both quantitative and qualitative results show that the reconstructed signal of this method is slightly better than that of VMD and far better than that of EEMD and CEEMD. Not only have the high-frequency noise been removed, but also the low frequency components mixed with effective signal is greatly reduced in its spectrum and time-frequency diagram. It is notable that the method does not need to select the basic function like WT, and the boundary position between noisy and valuable modes is determined automatically. It is very practical for adaptive noise suppression for different MS signals and rapid processing of large data sets.  
[PERSON] wrote the manuscript. [PERSON] processed the signal data. [PERSON] conceived the research, provided some suggestions for the research and revised the article. All authors have read and agreed to the published version of the manuscript.  
The National Key R &D Program of China (No. 2017 YFC1501100) and the National Natural Science Foundation of China (No. 51679158).  
Thanks to colleagues and teachers who contributed to this project at Shuangjiangkou Hydropower Station.  
The authors declare no conflict of interest.
###### Abstract  
Citrus cultivation represents one of the major economic pillars of the Valencian Community (Spain). Frost events pose a significant threat to these plantations, resulting in substantial economic losses. This study aims to assess the frequency and intensity of frost occurrences in the region from 2004 to 2023, using Meteosat Second Generation satellite imagery. These images provide daily land surface temperature data at 15 min intervals. Frost days were defined as those when temperatures fell below \(-2.3\,^{\circ}\)C, the threshold at which orange fruits become susceptible to damage, with different temperature thresholds applied to estimate varying levels of crop damage. Frost duration was also analyzed to classify event intensity and its potential impact on citrus crops. Annual comparisons revealed a decline in both the severity and frequency of frosts, particularly in cases of \"moderate\" and \"intense\" damage, supporting forecasts of increased regional aridity and suggesting new opportunities for expanding citrus cultivation to higher altitudes. When compared with farmers' records, this study's methodology proves effective in assessing frost impact and offers potential use for winter crop insurance. Validation was conducted using in situ data from the Spanish National Meteorological Agency (AEMET).  
citrus crops; remote sensing; frost damage; Valencian Community 2025