esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 OFDM Based Multicarrier Modulation Schemes  
[PERSON] _et al_. [9] proposed OFDM as a promising candidate for a flexible spectrum pooling system. The advantages of using OFDM in cognitive radio systems were discussed in [10]. OFDM reduces the time dispersion effect of multipath channels encountered with high data rates, by using cyclic prefix (CP). A cyclic prefix of length greater than the maximum delay spread of the channel is generally used with OFDM to overcome intersymbol interference. This CP-OFDM modulation transforms a frequency selective channel into a group of several flat fading channels, leading to a one tap zero-forcing (ZF) equalization per sub-carrier and thus reduces the requirement for complex equalizers. Advantages of OFDM include high spectral efficiency, robustness against narrowband interference (NBI), easy implementation using FFT and reconfigurability of transmission parameters. These advantages, together with the spectrum sensing capability using FFT and spectrum shaping capabilities, make OFDM the most appropriate transmission technology for CR systems. Allocation of radio resources is a major challenge in OFDM systems. In [11; 12], the problem of optimal resource allocation for an OFDM based CR system has been addressed. In [13], the authors have proposed an improved joint subcarrier and bit allocation scheme for cognitive user with primary users' cooperation, in an OFDM based underlay CR network. The authors investigated the performance of cognitive spectral efficiency and the average interference power level. Using numerical analysis it was shown that, the SU's spectral efficiency increases significantly and the interference power level at the PU receiver decreases dramatically for the proposed scheme compared with the traditional non-cooperation scenario.  
There are some limitations of OFDM in CR networks [10]. The drawbacks of conventional OFDM systems include large side-lobes of the modulated OFDM subcarriers and large peak-to-average power ratio (PAPR) [6]. The side-lobes result in significant adjacent channel interference among different secondary users and between primary users and secondary users. Large PAPR leads to nonlinear distortion of OFDM signals at the transmitter power amplifier. In [14; 15; 16; 17; 18; 19], various sidelobe suppression techniques and PAPR reduction techniques were proposed for OFDM based CR systems.
## 4 Results and Discussion
### Sensitivity Analysis  
Figure 14 shows the sensitivity of the carbon footprint in relation to the transportation inputs from the three evaluated industrialization scenarios. The operation of transport in the product system was selected since a considerable environmental impact was demonstrated, mainly from the cultivation stage in the agro-industrial processes [65; 66]. For the current sensitivity analysis, this was carried out by varying the distribution centers of the inputs considered in the base case, which were those reported by local producers during field interviews. Sales centers for the main inputs were located both closer to the current ones and further away; thus, the environmental impact in the product system was quantified. It was shown that the sales centers closest to the study area decreased the impacts generated from the carbon footprint by 15%, while the most remote sites increased the quantification of the impact by around 33%. Despite having distribution centers close to the production area, the economic factor may be relevant in the producers' decisions for the selection of the current site for input acquisition at the expense of other factors, such as the quality of the product or even environmental aspects.  
Figure 13: The energy footprint of dehydrated pineapple by the main processes.  
This coincided with [PERSON], [PERSON], and [PERSON] [67], who reported that inefficiencies in the management of suppliers and shipping routes generated higher CO\({}_{2}\) emissions. A greater change in GHG emissions was also shown in the pineapple packing and dehydration processes. During these processes, there was more dependence on the quantity of pineapples transported from the cultivation areas. Additionally, some inputs for packaging materials were purchased from places far away from the study site. For the pineapples in syrup process, some of the required inputs were acquired in areas close to the place of processing, i.e., the sugar for the syrup was transported from a nearby sugar cane plant.
## 3 Results and Discussion
### Response of GWFP to Climate, Crop, and Remote Sensing Parameters  
The correlation coefficients between GWFP and the following parameters (effective precipitation (Pe\({}_{\text{eff}}\)), minimum temperature (Tmin), relative humidity (RH), solar radiation (Rn), EVI, NDVI, and NDWI) are positive (Figure 15). The highest correlation coefficient was 0.99 between GWFP and Pe\({}_{\text{eff}}\) and 0.34 between GWFP and RH, whereas the fraction of the NDVI had a very low positive correlation with GWFP at 0.0086. Since the growing season occurs in the summer in Sudan, which is situated in a dry region and relies mainly on rainfall for irrigation, the effective precipitation showed a strong correlation with GWFP at 0.99. Factors such as maximum temperature (Tmax), wind speed (WS), Etc, yield, sawn area, and SAVI exhibited a negative correlation with GWFP. Specifically, the maximum temperature displayed the highest negative correlation coefficient of \(-0.24\) with GWFP. Through the examination of correlation coefficients, it was observed that climatic parameters, followed by remote sensing data, and ultimately crop parameters, had the most significant influence on GWFP.  
Figure 14: Relative contributions of 13 input variables to green water footprint.
## 1 Introduction
Attack graphs (AG) are generated by the control plane according to the active topology, and they are used to identify the vulnerable nodes. From the AGs, it is possible to know in advance what portion of the network needs to be monitored. This information is offloaded in the form of network rules to the programmable data plane components, which will then alert the control plane if an anomaly is spotted. GRAPH4 can ensure a robust and resilient security posture, thereby allowing for the prompt mitigation of security incidents, thus optimizing and distributing the computation of the metrics. Leveraging switch programmability based on security scores allows for timely reactions to unexpected conditions: this dynamic approach optimizes resource allocation, minimizes response times, and fosters proactive defense. We demonstrate how GRAPH4 can save a big part of the network computation using simple AGs, especially for computationally expensive metrics. The main contributions of this paper are as follows:  
* We present a security monitoring architecture that integrates attack graphs generated on the control plane with anomaly detection metrics calculated on the data plane. * We demonstrate how the control plane can exploit its knowledge of the network configuration in order to optimize the allocation of low-level metrics collectors, thus placing them only on specific data plane devices. * We evaluate the effectiveness of GRAPH4 presenting a PoC related to Distributed Denial of Service detection. The paper is organized as follows: in Section 2, we expose the concepts that we used in our work, in particular security metrics and DPP with a focus on the P4 programming language. In Section 3, we proceed to review the related literature. In Section 4, we propose the GRAPH4 architecture explaining its main components and features. In Section 5, we provide a proof of concept on a real use-case scenario with DDoS attacks as an example, thereby showing the improvements that we can obtain with respect to existing solutions. In Section 6, we discuss the limitations of the study. Lastly, Section 7 includes our conclusion and proposals for future works.
## 2 LFC Modeling in the Hybrid AC/DC System with Virtual Inertia
### LFC for AC/HVDC System with Emulated Inertia by ESS  
In this part, we continue to model the LFC in the test system equipped with not only AC/HVDC transmission lines but also bulk ESS for inertia emulation. Note that a virtual inertia could be emulated by the added bulk ESS to improve the inertia response of conventional generators to load variations. In this article, the inertia emulation is realized by derivative control. Then, the emulated power from ESS for Area \(i\) can be written as  
\[\Delta P_{ESS_{i}}(s)=\frac{J_{em_{i}}}{1+sT_{ESS_{i}}}[s\Delta\omega_{i}(s)]\,, \tag{11}\]  
where \(T_{ESS_{i}}\) denotes the time constant of the derivative control loop and \(J_{em_{i}}\) is the control gain representing the emulated inertia. We can see that the above derivative control loop calculates the rate of change of frequency (ROCOF). To be highlighted, instead of wide-area frequency data for the supervisory AGC and SPMC loops in the proceeding, only the local frequency information would be used for a relatively faster response in the derivative control-based inertia emulation. The selection of control gain \(J_{em_{i}}\) is based on an iterating tuning approach where the frequency deviations are minimized; we refer to the work in [34] for details. Considering that the derivative control loop could be sensitive to the noise, one may add a low-pass filter to the model to eliminate the effects of noise [32] (here we consider the filter's effects through the time constant \(T_{ESS_{i}}\)). The storage part of ESS will remain charged during normal operation, and it starts to help the system once contingencies occur. Note that the ESS mainly works for a short period of time (2 s to 5 s) to emulate inertia.  
In the end, adding the emulated active power from ESS and also the power modulated by the HVDC link in Section 2.2, the Equation (3) of frequency dynamics in Area \(i\) will be changed to  
\[\Delta\omega_{i}(s)\ =\ \frac{K_{pi_{i}}}{1+sT_{pi_{i}}}[\sum_{g=1}^{G_{i}} \Delta P_{mi_{g}}-\Delta P_{di_{i}}-\Delta P_{tie,AC}-\Delta P_{DC}+\Delta P_{ ESS_{i}}]\,. \tag{12}\]
## 4 Discussion
### Derivation of the Material Constants in Paris Law Based on the Tanaka-Akinitwa Model
In both cases when the total facet area and the major facets area were applied, a larger \(m\) and a smaller \(C\) were derived for the internal fracture mode compared with that of surface fracture. The relatively large value of \(m\) but smaller \(C\) of the internal fracture regime has been reported in several studies [12; 13; 14]. In addition, the effects of the stress ratio on the \(S\)-\(N\) curve were almost diminished for both surface and internal fracture. In the plot of the internal fracture mode, when the total facet area was used, the plots were very scattered, and as thus, the material constants might not be accurately acquired. However, when the major facet area was used, the plots showed less deviation and a better linear relationship, indicating that the major facet(s) is appropriate for determining the real initiation site of the internal cracks. These observations indicate that the facets of the internal cracks follow two-step facet initiation and propagation behaviors. In contrast, in the surface fracture regime, both the total facet area and the major facet area showed acceptable plot distribution and linear relationship for calculating the material constants. That can be explained as follows: The coefficient material constant \(C\) was 10-20 orders larger in the surface fracture regime than in the internal fracture regime. This indicates that the crack propagation rate of the surface fracture was much faster than that of the internal fracture. Consequently, the high surface propagation rate enabled the propagation of the crack through a grain and overcame the restraints of the microstructural effect, which in turn makes the determination of the crack initiation sites less important or even negligible.
## 3 Results and Discussion  
### X-ray Diffraction (XRD), Element, and Morphology Analysis of LDH  
Figure 1 shows XRD pattern of Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH. The Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH exhibit (0 0 3), (0 0 6), (0 1 2), (0 1 5), (0 1 8), (1 1 0), and (1 1 3) characteristic diffraction peaks of the LDH structure, which can be indexed in a hexagonal lattice with an R3m rhombohedral space group symmetry [43; 44]. These reflection positions are in good agreement with those of the reported LDHs [43; 45]. Figure 2 illustrates the EDS analysis and TG curve of Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH. From the TG curve, it can be seen that the Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH mainly underwent two stages decomposition. The first stage corresponds to the loss of physical absorbed water and interlayer water in the range of 50 to 200 \({}^{\circ}\)C [46]. The second stage in the range of 200 to 800 \({}^{\circ}\)C is associated with the dehydroxylation of the metal hydroxide layers and the degradation of carbonates [47]. The TG analysis showed the mass loss percentages of H\({}_{2}\)O molecules for Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH. The composition of other elements was obtained using the Leco CHNS-932 elemental analyzer (Leco Co., Saint Joseph, MO, USA) and atomic absorption apparatus (AAS) (Purkinje General Instrument Co., Beijing, China). The chemical formula of the Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH is Ni\({}_{0.16}\)Mg\({}_{2.55}\)Al(OH)\({}_{7.42}\)(CO\({}_{3}\))\({}_{0.50}\cdot\)H\({}_{2}\)O\({}_{1.53}\). This chemical formula is in good agreement with the EDS elemental analysis results. Both AAS test and EDS analysis proved the existence of Ni ions in Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH.  
Figure 3 shows the SEM image of Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH. It can be seen that the morphology of Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH is petal-like sheet particles with many cavities. Furthermore, in order to obtain more fine morphology and particle size, the TEM image of Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH is shown in Figure 4. As seen from the TEM image, Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH has a flake nanoparticles morphology.  
Figure 1: X-ray Diffraction (XRD) pattern of Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH.  
Figure 3: Scanning electron microscope (SEM) image (40,000\(\times\)) of Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al–LDH.  
Figure 2: X-ray energy dispersive spectroscopy (EDS) and thermogravimetric (TG) curve of Ni\({}_{0.2}\)Mg\({}_{2.8}\)Al-LDH.
## 1 Introduction
The overcut in EDM die-sinking is another issue that ultimately influences the geometrical accuracy [21]. With respect to machining holes through EDM the difference between the designed geometry and machined geometry is very common [22]. It has been reported that the overcut especially in the case of hole making through EDM is highly difficult to forecast since there exists a complex and non-linear relationship of tool wear, tool diameter, and discharge parameters [23]. In a study presented in [24] the side over cut of the electric discharge machined (EDMed)hole has been significantly reduced by a varying electric field around the electrodes. Geometrical errors (radial and axial) caused by EDM die-sinking can also be controlled through the proper selection of tool material and the electrode polarity [25]. In the present study the overcut at the hole entrance and the under-cut at the hole exit are also considered as the performance measures of EDM through relief angled electrode designs. Among other parameters affecting the MRR during EDM, the role of flushing method also plays an important role especially in the case of a hole formation. The melt debris accumulate in the partially drilled hole and solidify with the internal walls of the hole [26]. To overcome this difficulty many researchers provided the rotary motion to the tool to facilitate the expulsion of melt debris [27] and the associated phenomenon is termed as self-flushing [28]. [PERSON] et al. [29] reported that resticking of the melt debris on the machined surface is soundly observed when WC is machined through EDM. Provision of tool rotation has soundly overcome the restick problem of debris. [PERSON] et al. [30] evaluated the performance of EDM by adding oxygen in the dielectric and using rotary tool electrode. Improvement in MRR is achieved, however the hole overcut and the recast layer thickness are adversely increased. From the literature, it can be concluded that several attempts are being carried out to get improved outcomes of EDM. Conventionally, the straight cylindrical tool is used in sinking-EDM to produce through holes. Novelty of the present research is the first-time use of relief-angled tool electrodes to improve the EDM performance. As in the case of cutting tools used in conventional machining, the relief angle facilitates the machining performance. Likewise, different relief angles are provided to the bottom of the tool electrode and through-holes are produced in WC. The machining time (MT), hole taper angle (\(\omega\)), radial overcut (ROC), radial undercut (RUC), and surface roughness (SR) are considered as the responses. A significant improvement in machining time was achieved under the relief-angled tool electrode. Therefore, an extension of the relief-angled tool design is proposed naming as \"relief angle with land\". The results in terms of the said response characteristics are found to be highly encouraging when the WC is subjected to be machined with modified tool design.
# Postural Control in Children with Cerebellar Ataxia
## 4 Discussion
### Putative Compensatory Network  
Finally, it remains to figure out which neural substrate could be involved in functional compensation. In this regard, it is interesting to highlight recent evidence showing subcortical bidirectional connections between the basal ganglia and the cerebellum [51; 52; 53].  
The functional role of the basal ganglia to cerebellum connections has been deeply investigated. Indeed, it has been observed that patients with Parkinson's disease (PD) show abnormal functioning also in the cerebellum [54; 55]. A SPECT study in patients with PD confirms an increased cerebellar activity when the effect of the anti-parkinsonian drug extinguishes [56]. Considering the reciprocal connectivity, it is of interest that functional MRI has shown increased putamen-cerebellar activity in patients with PD performing simple motor tasks and that greater putamen-cerebellar connectivity is significantly correlated with better motor performance. On the contrary, the administration of levodopa, which compensates the low endogenous dopamine production in patients with PD, has reduced this connectivity, relieving the cerebellum from its compensatory task [57]. It has also been observed that the compensatory role of the cerebellum contributes to preventing the full manifestation of the typical motor symptoms during the initial stage of PD; this compensatory ability saturates with time, leading these patients to develop cerebellar symptoms too [58].  
These pieces of evidence allow arguing that, reciprocally, intact basal ganglia may compensate for cerebellar deficits. This hypothesis is still to be demonstrated, but should it be proved, it would provide a straightforward explanation for the graded postural impairments we found in children affected by PCA, as well as for the worse impairments reported in adult patients with cerebellar ataxia [46]. Evidence in this regard might come from functional MRI and diffusion tensor imaging techniques.
# Security of IoT Application Layer Protocols: Challenges and Findings
## 5 Service Discovery Protocols
### Mitigations  
As already pointed out, mDNS does not provide any built-in security feature. Therefore, since the protocol is affected by various threats, the development of effective mitigation measures is of paramount importance. The solutions could rely on simple measures often provided by operating systems or on more sophisticated measures provided by the services built on top of the mDNS protocol. More specifically, simple measures--mainly mitigating DDoS attacks--could focus on the following aspects:  
* Reduction of attack surface by disabling mDNS services whenever not needed;
* Block of the traffic from/to outside the local link by disabling the mDNS UDP port 5353.  
In fact, mDNS protocol is often enabled by default on most devices, but users might not be aware of this protocol running on their devices. Moreover, although mDNS has been designed for local link, sometimes services are openly accessible from the Internet.  
More sophisticated measures ensure the following security requirements:* _Authenticity_: query and response messages should be signed by the sender to allow the recipients to verify the sender's identity;
* _Confidentiality_: query and response messages should be encrypted to prevent any possible abuse of their content.  
Privacy is a major challenge for mDNS environments. Some research works propose solutions to mitigate this risk. More specifically, the works of [PERSON] and [PERSON] [67; 68] focus on a privacy-aware mechanism that protects multicast communication by encrypting all data, including potentially sensitive information. In addition, to reduce the network traffic, the mechanism limits the usage of multicast communications by proposing the concept of trusted devices that securely exchange unicast messages.  
To cope with the lack of built-in authentication mechanisms, some papers [69; 70; 71] propose specific solutions for robust authentication. In particular, [PERSON] et al. [71] develop protocols for private mutual authentication and service discovery that could be deployed over mDNS.
## 2 RASMR for Big Data Analysis under GLM
### Response-Aided Score-Matching Representative Approach  
In this section, we propose a new algorithm (see Algorithm 1 for its pseudocode) with further splits based on the response variable \(y_{i}\)'s, and call it the response-aided score-matching representative (RASMR) approach. This suggests that further splits may at most quadruple the original number of data blocks. Since the time complexity of the original SMR is \(O(Np)\)[43], which does not depend on the number of data blocks, the RASMR algorithm consumes no significantly more time than the SMR algorithm (see Section 4.2). Its time complexity is \(O(Np)\) as well.  
\begin{table}
\begin{tabular}{l c c} \hline
**Link Function** & \(\eta_{l}\) **for \(S_{0}(\eta)\)** & \(\eta_{r}\) **for \(S_{1}(\eta)\)** \\ \hline logit & \(-1.278464542761\) & \(1.278464542761\) \\ probit & \(-0.839923675692\) & \(0.839923675692\) \\ cloglog & \(-1\) & \(0.729114174900\) \\ loglog & \(-0.729114174900\) & \(1\) \\ cauchit & \(-0.801916425045\) & \(0.801916425045\) \\ \hline \end{tabular}
\end{table}
Table 1: Splitting points for Bernoulli models with different links.  
**Remark 1**.: _The iteratively reweighted least squares (IRLS or IWLS) procedure has been widely used for finding the MLE of a GLM [48; 49; 50]. Nevertheless, some more robust variants of IRLS have been proposed to make the estimates less sensitive to outliers (see [51] and references therein). One may choose a more robust procedure than IRLS in Algorithm 1, given that the targeted parameter estimate \(\hat{\mathbf{\beta}}\) is under the same criterion._  
**Remark 2**.: _Following the splits described in (2) of Algorithm 1, according to Theorems A2-A6 in Appendix A, many sub-blocks yielded a unique solution to (3). There are still leftover cases for normal/linear, Bernoulli, Poisson, and inverse Gaussian models, under which, some sub-blocks may yield up to two solutions to (3). For those cases, according to the proofs of Theorems A2-A4 and A6 (see Section S6 in the Supplementary Materials), we may further split such a block into two sub-blocks according to the peak value \(\eta\) of \(S(\eta)\), which is \(\frac{1}{2}\hat{y}_{kl}\) for normal/linear models, \(\eta_{l}\) or \(\eta_{r}\) for Bernoulli models, \(u(y_{kl})\) for the Poisson models, or \((4\hat{y}_{kl}^{2})^{-1}\) for the inverse Gaussian models. Based on our experience, such a split often leads to data blocks with a unique solution to (3)._