esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 The Time Source Techniques
### Global Navigation Satellite Systems
#### 3.1.5 Application  
Due to its flexibility, convenience, and low cost, GPS timing is widely used across various sectors, including power grids. Utilities rely on precise GPS-based timing to accurately timestamp data and measurements for all applications listed in Section 2, such as disturbance analysis, PMUs, and protection devices.  
NERC recommends that organizations develop a master plan for their timing technologies to ensure that as GPS usage increases, reliability-critical applications remain unaffected by potential GPS disruptions [43]. One approach to enhance resilience is the addition of redundant or backup clocks.
# Microbial Biopolymers: From Production to Environmental Applications--A Review
## 2 Microbial Polymers
### Xanthan Gum  
The commercially grown _Xanthomonas camepstris_ bacteria secretes xanthan gum, an exopolysaccharide [118]. It is a high molecular weight microbial biopolymer that belongs to the heteropolysaccharide category. Primarily, the carbon supply for the production of xanthan gum comes from the substrate's glucose and sucrose. Xanthan gum is constituted of a mixture of glucuronic acid, mannose, and glucose units of repetition adjoined by \(\beta\) (1-4) linkages. It is generally obtained by an aerobic fermentation approach accompanied by precipitation in isopropyl alcohol. The kind of fermenter employed, the way it is used (batch or continuous), the culture medium, and the growth parameters, such as the pH level, temperature, and oxygen in the medium, all affect the synthesis of xanthan [119]. It readily dissolves in cold water and displays strong pseudoplastic flow characteristics [120]. Its structural arrangement is extremely branched and complex. It is one of the most promising and commercialized biopolymers that has been used for the entrapment of living cells [121]. Because of its structural divergence and rheological characteristics, it can be employed for a variety of applications. [PERSON] et al. [122], [PERSON] et al. [123], and [PERSON] et al. [124] investigated the application of xanthan gum for soil stabilization and to improve soil water-retention efficacy. [PERSON] et al. [125] and [PERSON] et al. [126] employed xanthan gum to boost oil recovery. Oil recovery was improved due to wettability modification, and increased water viscosity was achieved using a nano-polymer suspension. The findings of [PERSON] et al. [127], [PERSON] and [PERSON] [128], [PERSON] et al. [129], [PERSON] and [PERSON] [130], [PERSON] et al. [131], and [PERSON] et al. [132] described that because of its exceptional selectivity, recovery, and reusability after regeneration, xanthan gum is a phenomenal biomaterial for the immobilization of heavy metals and an adsorbent of cationic dyes. Moreover, xanthan can also be used for developing edible films and coatings for the shelf-life extension of agriculture and horticulture produce [133; 134; 135]. [PERSON] and [PERSON] [119] claimed in their study that by using ultrafiltration after fermentation, the consumption of energy while recovering xanthan gum can be reduced by 80%. The main challenges involved in producing xanthan gum through microbial fermentation are viscosity obstacles. They also concluded that by employing a centrifugal-packed bed reactor, the viscosity problem can be overcome. Additionally, it was found that membrane-assisted deposition significantly increased membrane flow while using fewer accumulating solutes, leading to a significant increase in separation efficiency.
## 3 Results  
### Microleakage Test  
Wedge-shaped cervical cavities prepared on both buccal and oral surfaces of extracted premolars were restored with two hybrid conventional (Beautiful II LS(r)/B, Shofu Dental Corporation, Kyoto, Japan; Dynamic Plus(r)/D, President Dental, Munchen, Germany) and two flowable (Beautiful Flow Plus(r) F03/BF, Shofu Dental Corporation, Kyoto, Japan; Dynamic Flow(r)/DF, President Dental, Munchen, Germany) resin composites. On each tooth, the cervical borders of the two cavities were located in enamel and cement, respectively. After being removed from dye solution, sectioning of the teeth was accomplished followed by an evaluation of the dye penetration at the restoration-tooth interface. Subsequently, optical microscopy was employed to quantify the marginal microleakage at the restoration site. A combination of SEM and EDX was considered an optimal method to observe the quality of the adhesive interface and its neighboring structures. The relative compositions of restoration-tooth structures were also provided. The cervical and occlusal marginal microleakage ratios (RMLKc and RMLKo) were calculated for both types of cavities using optical microscopy images. Therefore, Table 2 provides an overview of the lengths of dye penetration measured for the sections of tested materials and their ratios related to the length of the adhesive interface for enamel-located restorations. The data for cement-located restorations are shown in Table 3.  
No significant association has been identified between the type of material and the efficacy (zero infiltration observed for 7/10 B sections, 6/10 BF sections, 4/10 D sections, 6/10 DF sections) for RMLKc in enamel-located restoration ([PERSON] exact test: \(p\)-value = 0.60323). Excepting the D where the efficacy was 8/10 sections, all other materials showed the efficacy of 10/10 sections for RMLKo, but the difference does not reach the statistical significance ([PERSON] exact test: \(p\)-value = 0.20193). No significant association has been identified between the type of material and the efficacy (zero infiltration observed for 8/10 B sections, 8/10 BF sections, 3/10 D sections, 6/10 DF sections) for RMLKc in cement-located restorations ([PERSON] exact test: \(p\)-value = 0.06189). Except for the D (9/10 sections) and DF (8/10 sections), all other mate rials showed the efficacy of 10/10 for RMLKo, without statistically significant association ([PERSON] exact test: \(p\)-value = 0.32186). No significant differences between enamel-located and cement-located restorations were observed regarding RMLKc (Figure 2(a1,a2), \(p\) = 0.3570) or RMLKo (Figure 2(b1,b2), \(p\) = 0.502).
# Compact Four-Port Circularly Polarized MIMO X-Band DRA
## 3 Two-Port MIMO Antenna  
A two-port CP MIMO DRA was designed as shown in Figure 6. Two structures were investigated: one with the full ground, and another with defected ground structure (DGS), as shown in Figure 6a,b, respectively. Figure 7 shows the frequency response of the S11 parameter and AR in both cases. Table 1 shows the performance of both antennas. As usual, the DGS structure enhanced the impedance bandwidth and improved the isolation between ports. Furthermore, the appropriate incorporation of slots in the ground plane improved the AR bandwidth. The phase differences between orthogonal modes could be preserved at the required limit with their desired magnitude; hence, the AR bandwidth was improved after the incorporation of the DGS. Here, in two-port antennas, the edge-to-edge separation between the DR elements was kept as 2.8 mm (0.08\(\lambda_{\mathrm{o}}\) at 8.5 GHz) with a center to the center separation of 15 mm (0.4\(\lambda_{\mathrm{o}}\) at 8.5 GHz).  
Increasing the distance between antenna elements being represented by X, the mutual coupling decreased, but the size of the antenna increased. The circular polarization at the proposed band of the antenna was affected by keeping the radiators close to each other. So, the distance between antenna elements was optimized to achieve low mutual coupling with compact size, and maintain the circular polarization. Figure 8a-c present the S11, AR, and S21, respectively, corresponding to various separation distances among the two-element DRAs. The optimized distances among DRAs were chosen on the basis of a parametric study; Figure 8 shows that the optimized separation distance as X = 15 mm provided a better 3 dB.  
Figure 4: E-field distribution in z = 5.17 mm, z = 5.17 mm plane: (**a**) 9.64 and (**b**) 11.88 GHz.  
Figure 5: E-field distribution in z = 5.17 mm, z = 5.17 mm plane at frequency of 9.77 GHz at the different time instants.
# Fault Diagnosis for a Class of Robotic Systems with Application to 2-DOF Helicopter
## 2 Preliminaries
### Generalized Hamiltonian Systems
#### 2.1.1 Non-Linear Observer for Generalized Hamiltonian Systems  
A non-linear observer for the generalized Hamiltonian is considered in refs. [24; 27]. Considering the linear mapping of the output \(y\) given by  
\[\dot{x} = [J(y)+S(y)]\frac{\partial H(x)}{\partial x}+F(x)+Gu, \tag{7}\] \[y = C\frac{\partial H(x)}{\partial x}, \tag{8}\]where \(C\) is a constant matrix of an appropriate dimension. Therefore, an observer for the system (7) and (8) is defined by  
\[\dot{\hat{x}} = [J(y)+S(y)]\frac{\partial H(\hat{x})}{\partial\hat{x}}+F(\hat{x})+Gu +K(y-\eta), \tag{9}\] \[\eta = C\frac{\partial H(\hat{x})}{\partial\hat{x}}, \tag{10}\]  
where \(K\) is the observer gain, \(\hat{x}\) the estimated state, \(\eta\) the estimated output, in terms of \(\hat{x}\), and \(\partial H(\hat{x})/\partial\hat{x}=M\hat{x}\) is the gradient vector.  
The error of state estimation is defined as \(e=x-\hat{x}\), while the estimation error of output is \(e_{y}=y-\eta\).  
\[\dot{e} = J(y)\frac{\partial H(e)}{\partial e}+[S-KC]\frac{\partial H(e)} {\partial e}+\tilde{F}(x,\hat{x}), \tag{11}\] \[e_{y} = C\frac{\partial H(e)}{\partial e}, \tag{12}\]  
where \(\tilde{F}(x,\hat{x})=F(x)-F(\hat{x})\), and  
\[\frac{\partial H(e)}{\partial e}=\frac{\partial H(x)}{\partial x}-\frac{ \partial H(\hat{x})}{\partial\hat{x}}=M(x-\hat{x})=Me. \tag{13}\]  
The design conditions are described in the following theorem, see refs. [24; 27]:  
**Theorem 1**.: _The state \(x\) of the nonlinear system (7) and (8) can be estimated by system (9) and (10) if the pair \((C,S)\) is observable or at least detectable and the matrix_  
\[\Xi=M\left[S-\frac{1}{2}(KC+C^{\mathrm{T}}K^{\mathrm{T}})\right]M+\Pi, \tag{14}\]  
_where \(\Pi=\frac{1}{2}\left[M\frac{\partial F(x)}{\partial x}+\frac{\partial F(x)}{ \partial x}^{\mathrm{T}}M\right]\) is negative definite. In the above conditions \(e^{*}=0\) is locally exponentially stable._  
Proof.: See Appendix A.
# Multibeam Wideband Transmit Beamforming Using 2D Sparse FIR Trapezoidal Filters
### Wideband vs. Narrowband Systems in Modern Applications
#### 1.2.1 Beam Sharpness vs. Degrees of Freedom  
The sharpness of a given beam can be increased only by increasing the size of the physical aperture; the larger the number of antennas used, the larger the physical aperture, and thus the sharper the beams. Let the number of independent plane-waves that must be launched from an aperture be \(K\). Then, \(K\leq N\), where \(N\) is the number of elements used. When \(K=N\), one obtains the maximum degrees of freedom, i.e., support for the maximum number of independent plane-waves from the array.
###### Abstract  
The electromagnetic spectrum is used as a medium for modern wireless communication. Most of the spectrum is being utilized by the existing communication system. For technological breakthroughs and fulfilling the demands of better utilization of such natural resources, a novel Reflective In-Band Full-Duplex (R-IBFD) cooperative communication scheme is proposed in this article that involves Full-Duplex (FD) and Non-Orthogonal Multiple Access (NOMA) technologies. The proposed R-IBFD provides efficient use of spectrum with better system parameters including Secrecy Outage Probability (SOP), throughput, data rate and secrecy capacity to fulfil the requirements of a smart city for 6 th Generation (6 thG or 6G). The proposed system targets the requirement of new algorithms that contribute towards better change and bring the technological revolution in the requirements of 6G. In this article, the proposed R-IBFD mainly contributes towards co-channel interference and security problem. The In-Band Full-Duplex mode devices face higher co-channel interference in between their own transmission and receiving antenna. R-IBFD minimizes the effect of such interference and assists in the security of a required wireless communication system. For a better understanding of the system contribution, the improvement of secrecy capacity and interference with R-IBFD is discussed with the help of SOP derivation, equations and simulation results. A machine learning genetic algorithm is one of the optimization tools which is being used to maximize the secrecy capacity.  
6G; B5G; in-band full-duplex; reflective-in-band full-duplex; non-orthogonal multiple access; machine learning genetic algorithm; secrecy capacity +
Footnote †: journal:
# The Efficiency of Large Hole Boring (MSP) Method in the Reduction of Blast-Induced Vibration
## 5 Discussion  
### Analysis of Vibration-Increasing Factors  
Several factors that could influence blast-induced vibration were analyzed to estimate the cause of the high level of vibrations in the CB-2 pattern. Factors can be classified into rock mass and explosion characteristics, which are summarized in Table 6[14; 25; 26; 27]. Blast-induced vibration is not only directly related to the quantity of explosives and the distance between blast points and structures, but also the geological and geotechnical conditions of the rock in the excavation area[28]. Geological conditions and the distance between the blast face and structures indicate the properties related to the medium through which vibrations propagate, and these variables cannot be altered[29]. In particular, the spacing and orientation of the joint set and fractured zones have a significant effect on the vibration propagation characteristics[30; 31]. Furthermore, the blasting conditions indicate the properties associated with the source corresponding to the factors causing ground vibration. Several controllable parameters can be estimated using empirical methods and should be properly estimated depending on the geological conditions to minimize the vibration[32; 33]. However, these changeable parameters can lead to many unexpected variables during the blasting construction process, which can occur in combination and increase the vibration. Depending on the type of explosive, the time to reach the maximum pressure varies, and the vibration and frequency increase with time[14]. A low-vibration explosive has a detonation velocity of approximately 60% of that of an emulsion, which is commonly used in tunnel blasting. Although it generates a relatively low vibration, the insufficient crushing efficiency can lead to high-amplitude vibration caused by incorrect design[34; 35]. In general, electric/non-electric detonators used for blasting use chemical retarders to delay the detonation time, and these detonators can have errors in detonation time of up to 10%[36]. These errors can change the initiation time, and could cause difficulty in controlling the blast-induced vibration; thus, the error of the detonator might increase blast-induced vibration[37; 38; 39]. The accuracy of the delay time of the detonation is critical to the coupling of explosion energy and crack propagation between holes[40], and the sequence of detonation can be overlapped or reversed, causing greater vibration than expected[41; 42]. To minimize these detonating errors, an electronic detonator with 0.01% error has recently been employed[36]. Accurate or irregular drilling can increase efficiency depending on the blasting patterns, but sometimes vibration can increase owing to unexpected drilling errors[43]. Moreover, a decrease in burden or hole spacing can increase the explosion energy or occur a dead pressure caused by locally concentrated explosives[44], meanwhile, an increase in burden or hole spacing makes it difficult to break the rock mass.
# Implementation Aspects in Regularized Structural Equation Models
## 6 Summary of Simulation Findings
### RQ4: The Power \(p=0.5\) in the Penalty Function Can Be Sometimes Beneficial  
Fourth, the choice of the power \(p\) of the penalty function is ordinarily \(p=1\), but a recent implementation used \(p=0.5\) in SEM. Our simulations demonstrated similar performance of both power values (research question RQ4). However, in Simulation Study 2, \(p=0.5\) with a particular fixed regularization parameter \(\lambda\) outperformed the estimation based on \(p=1\). Moreover, the determination of the number of estimated parameters depended less on a chosen threshold for \(p=0.5\) than \(p=1\) if a differentiable approximation of regularized estimation was utilized.
# Multi-Target Detection Algorithm for Fusion Images Based on an Attention Mechanism
## 5 Experiments Results
### Experimental Evaluation Indicators  
After training, the model is evaluated on a validation set. Common evaluation metrics for object detection include precision, recall, accuracy, and mean Average Precision (mAP). A confusion matrix is often used to assess model performance, where rows represent actual classes and columns represent predicted classes. It consists of four elements: \(TP\) (True Positives), \(FP\) (False Positives), \(FN\) (False Negatives), and \(TN\) (True Negatives), as shown in Table 4.  
The confusion matrix can be used to calculate the evaluation indicators of target detection such as precision, recall, and accuracy, and further evaluate the effect of the model. The proportion of samples (\(TP\)) is calculated as follows:  
1. Precision The proportion of samples (\(TP\)) that are truly predicted correctly among all samples (\(TP+FP\)) with positive prediction results. The calculation equation is \(P=\frac{TP}{TP+FP}\).
2. Recall The proportion of samples (\(TP+FN\)) that can predict the correct (\(TP\)) among all positive samples. The calculation formula is \(R=\frac{TP}{TP+FN}\).
3. Accuracy The proportion of samples (\(TP+TN\)) that can predict the correct among all samples (\(TP+FN+FP+TN\)). The calculation equation is \(A=\frac{TP+TN}{TP+FN+FP+TN}\).  
When evaluating the model, by taking a series of confidence thresholds to divide the samples, multiple \(P-R\) values can be obtained. With recall rate \(R\) as the horizontal coordinate and precision rate \(P\) as the vertical coordinate, these \(P-R\) values are plotted on the image to obtain the \(P-R\) curve. The area enclosed by the curve and the coordinate axis is AP, and the AP of all categories in the entire dataset is mAP.
## 4 Discussion
Careful study of the spin and charge analysis obtained according to [PERSON]'s methodology revealed that, in all the of discussed cases, the spin of positively charged molecules is predominately located on the nucleobase moiety, except for \(\epsilon\)-dCyt, H-\(\epsilon\)-dCyt, and \(N\)2,3-\(\epsilon\)-dGua, as presented in Table 2. For the above 2\({}^{\prime}\)-deoxynucleoside adducts, unpaired electron migration was observed during solvent and solute relaxation (Table 2), i.e., in the vertical cation non-equilibrated solvent-solute state, as well as the equilibrated spin state, the unpaired electrons were found on the nucleobase moiety. In contrast, the unpaired electron migrated onto the etheno part of the adduct after structural relaxation in approximately 70% of cases. The ionisation potential is a convenient parameter for estimating the antioxidant potential of molecules. These systematic theoretical studies were performed using the Minnesota DFT functional M06-2x with a double-\(\zeta\) basis set with dispersion and polarisation functions (6-31++G**) for hydrogen and heavy atoms. The ionisation potential values were calculated as vertical (VIPNE and VIPEQ) and adiabatic (AIP). The results are presented in Table 3 and show that the lowest ionisation potentials (VIPNE, VIPEQ, and AIP) in [eV] were noted in the case of 2\({}^{\prime}\)-deoxyadenosine adducts with LPO products for H-\(\epsilon\)-dAdo (7.07, 6.25, 6.00, respectively). For 2\({}^{\prime}\)-deoxycytidine derivatives, the lowest values were noted for H-\(\epsilon\)-dCyt (6.78, 5.96, and 5.80, respectively) and for the 2\({}^{\prime}\)-deoxyguanosine series. The lowest were observed for (_SRR_) HNE-dGua (6.80, 6.07, and 5.72, again respectively). The above values are significantly lower than those obtained for parental canonical 2\({}^{\prime}\)-deoxynucleosides (Table 3). It should be pointed out that, by using the same methodology for the 7,8-dihydro-8-oxo-2\({}^{\prime}\)-deoxyguanosine, the VIPNE, VIPEQ and AIP values were observed were as follows: 7.15, 6.15, and 5.78 [eV]. Careful analysis of the ionisation potentials showed that \(N\)2,3-\(\epsilon\)-dGua and M1-dGua have higher values than those for dGua, while for _SRR_ and _RRR_, diastereomeric forms of HNE-Gua were similar to those of OXOdG (see Table 2).
## 5 Discussion
### Advantages of Asymmetry  
Our study highlights that the distributed asymmetric VR between VR-users and non-interactive desktop users is a valid low-cost solution to advance the communication and knowledge transfer between multinational and geographically dispersed departments in a variety of industrial use cases. The majority of experts were intrinsically motivated toward utilizing VR in any available form despite several usability issues. The experts' desire to adopt VR for their work tasks and synchronize it with product development milestones highlights the value of the designed COVE-VR system for industrial contexts.  
Expanding on the previous findings [17], our article suggests that asymmetric VR positively affects decision making and increases the number of employees who may participate and contribute to the collaboration process, because it enables accessibility for employees that do not have access to HMDs or other advanced technologies. Such asymmetry may further advance flexibility in terms of engagement levels and degree of participation in work activities [3], which potentially increases workplace satisfaction levels. Further, due to the ability to support industrial collaboration [4; 48; 49; 42] by providing rapid access to virtual prototypes and tools for content creation, asymmetric VR is a promising approach to advancing and integrating Lean and Agile industrial practices [19; 39]. Our study showed that distributed asymmetric collaboration in VR may reduce the number of iterations in product development and, thus, minimize lean waste and support cost reduction. It also allows faster and less expensive execution of industrial tasks, resulting in faster time-to-market and overall optimization.  
Our findings further indicate that such an asymmetric approach, apart from enhancing teamwork and communication between industrial departments from different countries, may also raise awareness and knowledge of VR among industrial employees with no previous experience and access to VR devices, which potentially delivers several benefits. One of the remote participants (a first-time user of VR, located in India) commented: _\"It was an amazing, very thrilling experience. Once when we get the real VR experience it would be great\"_ (**T2**). First, this allows extending the pool of test users, who might be included for further VR software development, which is critical for adopting and localizing the software for different cultural user groups in multinational companies. Additionally, such an approach would enable a smooth introduction to VR technologies and steadily prepare employees for Industry 4.0 interventions. Therefore, our study suggests that asymmetric collaboration between VR platforms and traditional conferencing software, such as Teams, is a worthy strategy to facilitate knowledge transfer between industrial experts, and is generalizable to other industrial contexts and collaboration scenarios.