esa-sceva/satcom-chunk-collection huggingface dataset:
## 6 Performance Evaluation
### Comparison of Security Properties  
This section compares the security features of the proposed scheme with those of other studies, including those by [PERSON] et al. [25], [PERSON] et al. [26], [PERSON] et al. [19], and [PERSON] et al. [24]. [PERSON] et al. [24] proposed a homomorphic encryption strategy to ensure secure searching and keyword-based access to the database, as indicated in Table 2.  
This plan is effective for approved data searches and IoT data sharing, yet it was not built for multiple-generator searches. [PERSON] et al. [19] introduced FB-IAV, a searchable encryption system that utilizes key aggregation and auxiliary input, facilitating the secure sharing of encrypted data. Nevertheless, the secret information associated with the \(dr\) keyword is not adequately protected. [PERSON] et al. [26] introduced an efficient attribute-based data encryption system with a concealed strategy to achieve restricted access. However, this initiative suffers from inadequate key management. [PERSON] et al. [25] also implemented a blockchain and aggregated key method with mutual authentication to provide access control and verifiable search. However, this approach incurs significant computational costs due to its authentication algorithm. Among the five proposed plans, only the suggested plan can ensure both accountability and the protection of requester privacy.
## 4 Discussion  
The present study aimed to provide some insights into the physiological responses of the endemic freshwater fish species _A. vistonicus_ in Vistonis Lake, in relation to the continuous fluctuation of the abiotic parameters in the lake.  
Temperature values exhibited seasonal fluctuations, a phenomenon that is generally observed in aquatic freshwater ecosystems [47, 48, 49]. As expected from previous studies and due to the hydrology of the lake [50], salinity values followed a seasonal pattern, with low values recorded during the cold months December-February and higher during the hot months June-August. The periodic inflow of seawater in coastal lakes, such as Vistonis Lake, is a common, but alarming phenomenon, since even small increases in salinity might cause serious defects in the biodiversity of the habitats and threaten the survival of the species [51]. DO and pH values did not show any strong fluctuations and were ranging among the permitted limits for cypriids [52]. pH values were constantly higher than 7, reflecting the alkaline character of the natural freshwater systems in Greece, and conductivity values were high, especially during the dry period, due to the seawater inflows in the lake [53].  
The peculiar hydrology of Vistonis Lake system, leading often to salinization, especially during the dry season, has resulted in species population decline, threatening thus its survival [28]. Species with restricted distribution, such as _A. vistonicus_, may be especially prone to extinction than others with wider distribution range [54]. Therefore, the importance for acute implementation of management plans for the protection and preservation of the species has already been recommended [28, 30]. Our results show that biomarkers of cellular stress responses could also be included in future management plans of the species, for achieving a better and more complete assessment of the biology of the species.  
Figure 7: Principal Component Analysis biplot of the CSR biomarkers (G = gills, L = liver) measured in _Alburnus vistonicus_ (\(n\) = 45, 5 fish per month) and mean values of the physico-chemical parameters measured in Vistonis Lake (northern Greece) during the sampling period (October 2014-September 2015). In the inserted table the factor loadings of each parameter on the two principal components (PC1 and PC2) are presented.
## 3 Colpitts Chaos Oscillator
### Colpitts Chaos Oscillator Mathematical Model  
According to [PERSON] et al. [42; 43], to produce a chaotic signal, an oscillator must have at least three state variable elements, such as capacitors or inductors, a nonlinear element, such as a diode or transistor, and an active component that is critical for maintaining oscillations. The Colpitts chaos oscillator design includes an NPN bipolar junction transistor \(Q_{1}\), biased within its active range via \(V_{1}\), \(R_{1}\), and \(V_{2}\). The feedback is incorporated via inductor \(L_{1}\) with series resistance \(R_{L}\) and a capacitive divider consisting of \(C_{1}\) and \(C_{2}\)[36]. Figure 2 depicts the Colpitts chaotic oscillator circuit.  
The mathematical model of the Colpitts chaos oscillator is described with the following equations:  
\[\left\{\begin{array}{l}C_{1}\frac{\mathrm{d}V_{CE}}{\mathrm{d}t}=I_{L}-I_{C} \\ C_{2}\frac{\mathrm{d}V_{CE}}{\mathrm{d}t}=\frac{V_{1}+V_{BE}}{R_{1}}-I_{L}-I_{ B}\\ L_{1}\frac{\mathrm{d}I}{\mathrm{d}t}=V_{2}-V_{CE}+V_{BE}-I_{L}\cdot R_{L}\\ \end{array}\right., \tag{1}\]  
where \(V_{CE}\) is collector-emitter voltage, \(V_{BE}\) is base-emitter voltage, \(V_{1}\) and \(V_{2}\) are circuit input voltages, \(I_{L}\) is inductor current, \(I_{C}\) is collector current, and \(I_{B}\) is base current.  
The nonlinearity of the Colpitts chaos oscillator is introduced in the base current (\(I_{B}\)) of transistor \(Q_{1}\). which is defined as follows:  
\[I_{B}=\left\{\begin{array}{l}0,\quad\text{if }V_{BE}\leq V_{TH}\\ \frac{V_{BE}-V_{TH}}{R_{ON}},\quad\text{if }V_{BE}>V_{TH}\\ \end{array}\right., \tag{2}\]  
\[I_{C}=\beta_{F}\cdot I_{B}, \tag{3}\]  
where \(V_{TH}\) is the threshold voltage, \(R_{ON}\) is the small-signal on-resistance of the base-emitter, and \(\beta_{F}\) is the forward current gain of the transistor.
## 5 Nano-Mn-Based Catalyst
### Composite MnO\({}_{x}\) Nanocatalysts
Advanced characterization and control experiments revealed that during the low-temperature processes, sulfate interacts with TiO2 to form a solid superacid (SO4\({}^{2-}\)-TiO2), which acts as an NH3 adsorption site and effectively inhibits the toxic effect of sulfate on the MnOx catalyst. Furthermore, this solid superacid (SO4\({}^{2-}\)-TiO2) species can weaken the redox performance to inhibit excessive NH3 oxidation, thereby significantly improving its high-temperature activity. Titanate nanotubes are expected to serve as a new carrier for Mn-Ce nanocatalysts. Jiang et al. [118] prepared manganese-cerium oxides supported on traditional titanium dioxide (MnCe-TiO2) and titanate nanotubes (MnCe-TiNTs) using the impregnation method. They investigated their catalytic activity for NO-NH\({}_{3}\)-SCR in flue gas with SO\({}_{2}\) and H\({}_{2}\)O and without SO\({}_{2}\). The results indicated that the TiNTs-supported MnO\({}_{\text{x}}\)-CeO\({}_{2}\) composite not only improves the low-temperature catalytic activity but also increases the N\({}_{2}\) selectivity of the catalyst and extends its active temperature window. Some ternary manganese nano-based catalysts have also been reported. Wu et al. [127] conducted an in-depth investigation of manganese dioxide-modified VO\({}_{\text{x}}\)-CeO\({}_{2}\) nanorods. These nanorods predominantly feature [110] and [100] facets on their surface. The exposed [110] facets are likely active for the NH\({}_{3}\)-SCR reaction, while the [100] facets contribute minimally. Additionally, a synergistic interaction exists between VO\({}_{\text{x}}\), MnO\({}_{\text{x}}\), and CeO\({}_{2}\) on the exposed [110] plane. The addition of manganese increases the redox cycle of V\({}^{5+}\)/V\({}^{4+}\) and further promotes the SCR reaction. Yao et al. [119] discovered that, compared to MnO\({}_{\text{x}}\)-CeO\({}_{2}\)-ZrO\({}_{2}\) nanorods (Mn-CZ-NR), the TiO\({}_{2}\)-modified catalyst Mn-Ti-CZ-NR exhibits higher catalytic activity. This is attributed to the greater number of oxygen vacancies, higher Ce\({}^{3+}\) content, larger Mn\({}^{4+}\) proportion, increased amount of surface adsorbed oxygen species, and enhanced surface acidity in the TiO\({}_{2}\)-modified catalyst. The TiO\({}_{2}\) modification effectively inhibits the non-selective oxidation of NH\({}_{3}\) to properly weakening the redox performance of the Mn-CZ-NR catalyst, thereby improving the N\({}_{2}\) selectivity.
## 4 Optimal Control Problem  
The optimal control problem is formulated to treat the hybrid dynamic system described in the previous section; therefore, it results in a multiple-phase optimal control problem, where each of the phases are as described in Figure 2.  
The general formulation of a multiple phases optimal control problem can be described as follows:  
\[\min\limits_{\mathbf{x},\mathbf{u},\mathbf{p},\mathbf{\dot{y}}_{0},s_{1},.., s_{nph}}\quad\sum\limits_{j=0}^{n_{ph}-1}\int_{s_{j}}^{s_{j+1}}\Phi_{L}(t, \mathbf{x}(t),\mathbf{u}(t),\mathbf{p})dt+\Phi_{M}(s_{j+1},\mathbf{x}(s_{j+1} ),\mathbf{p}) \tag{8}\]  
subject to:  
\[\begin{array}{rcl}\mathbf{\dot{x}}(t)&=&\mathbf{f}_{j}(t,\mathbf{x}(t), \mathbf{u}(t),\mathbf{p}),\\ &&t\in[s_{j},s_{j+1}]\\ &&j=0,\ldots,n_{ph}-1,\\ &&s_{0}=0,s_{n_{ph}}=T\\ &&\mathbf{x}(s_{j}^{+})&=&\widetilde{\mathbf{j}}_{j}(\mathbf{x}(s_{j}^{-}), \mathbf{p}),\,j=0,..,n_{ph}-1\\ &&g_{j}(t,\mathbf{x}(t),\mathbf{u}(t),\mathbf{p})&\geq&\mathbf{0},\,t\in[s_{j},s_{j+1}]\\ &&r^{\alpha}(\mathbf{x}(0),..,\mathbf{x}(T),\mathbf{p})&=&\mathbf{0}\\ &&r^{ineq}(\mathbf{x}(0),..,\mathbf{x}(T),\mathbf{p})&\geq&\mathbf{0}.\end{array} \tag{9}\]  
In the problem formulation, objective functions of Lagrangian type \(\Phi_{L}(\cdot)\) and/or Mayer type \(\Phi_{M}(\cdot)\) are minimized with respect to the states \(\mathbf{x}(t)\), the controls \(\mathbf{u}(t)\) and the model parameters \(\mathbf{p}\). These objective functions can be different for each phase, as described by the sum over the number of phases \(n_{ph}\). The constraints of the optimal control problem are defined in Equation (9), where \(\mathbf{f}_{j}(\cdot)\) is the differential equation describing the phase \(j\), with the duration of phase \(j\) being \(s_{j}\). The transition function between two consecutive phases is \(\widetilde{J}(\mathbf{x}(s_{j}^{-},\mathbf{p}))\). The path constraints are represented by \(g_{j}(\cdot)\), \(r^{\alpha}(\cdot)\) and \(r^{ineq}(\cdot)\) being the boundary conditions and point equality and inequality constraints.  
In the case of the walking problem, the number of phases is \(n_{ph}=10\), of which seven are continuous phases and three are the impacts, which are modeled as phases with zero time.
## 2 Related Work
\begin{table}
\begin{tabular}{p{42.7 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Protocol** & **Features** & **Advantages** & **Shortcomings** & **Reference** \\ \hline CO-EEORS & The best destination nodes are selected in this protocol based on lowest depth and distance values. If no relay nodes are found in neighborhood, then only destination nodes are selected. The MRC technique is used at the destination nodes. & It increases the packets delivery ratio and decreases the packets drop. & It increases the energy consumption and delay. & [5] \\ \hline DEADS & In this protocol, the network is divided into four zones based on depth. Depth threshold mechanism avoids data flooding. Power residing in a node’s battery and its depth decide its selection as a relay or as a destination. The nodes can move in the elliptical and linear direction. & It improves the network lifetime and packets delivery ratio. & The protocol fails in elliptical mobility pattern optimization, which increases packets drop. & [25] \\ \hline i-q,q,i approach & The coalition, physical awareness, link quality, and energy efficiency are the main goals of the proposed work. The energy usage of the devices is reduced when IOT devices communicate with each other, through the above factors. & The proposed work is best to increase the life of the framework. & How to achieve maximum PDR is not discussed. & [26] \\ \hline ACMWN & The algorithm defines a new clustering technique with good quality. The main task of the approach is to avail the techniques with maximum throughput and less delay. Selecting only one cluster eliminates the interference & The main achievement of the algorithm is to reduce the drop of packets, enhancing the transmission. & The framework has limited bandwidth. & [27] \\ \hline I,IP,P & The standby algorithm design is independent in properties, management and adaptation. The self energy adaptation mechanism is introduced. By using utility function, energy consumption will vary with the cluster head. & The goal is to enhance the energy and independence of the cluster. & The battery is [28] fixed and not rechargeable. \\ \hline AODV/PC & The scheme considers no mobility which avoids the complexity in getting nearby information and link measurement. Many clusters can be made more easily than the traditional mechanisms. & It avoids the high traffic on clusters. & The scheme & [29] \\ \hline S-PMAC & This framework uses advanced multiplexing wireless technique to deliver data between two devices. The physical and social behaviors of the users are used in connecting two devices. Similar nearby users with the same mobility can be found in a reference point. & The scheme & [29] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Related Work Summary.
## 2 Materials and Methods
### Nigella sativa and MRSA Susceptibility Test  
_Nigella sativa_ (NS) black seed oil, a product of Al Hussan Food Products Factory, Riyadh was purchased from a local herbal medicine shop in Al-Ahsa, Saudi Arabia. According to the manufacturer, it is 100% pure organic cold pressed oil. Undiluted and diluted forms of the oil extract were used for the investigation. Oil extract was diluted in 0.2% dimethyl sulfoxide (DMSO) to obtain concentrations of 1000 \(\mu\)g/mL, 750 \(\mu\)g/mL, 500 \(\mu\)g/mL, 250 \(\mu\)g/mL, and 100 \(\mu\)g/mL dilutions, representing 100%, 75%, 50%, 25%, and 10% concentrations. In these, 0.01 mL of each concentration was used to make the actual concentrations 10, 7.5, 5.0, 2.5, and 1.0 \(\mu\)g/mL. The susceptibility of the isolates was tested against these dilutions of NS by the well diffusion method. Mueller-Hinton agar (MHA) was seeded with each bacterial isolate and spread out to cover the entire surface of the agar using sterile cotton swabs, moistened with the bacterial suspension [29; 30]. Seven evenly distributed wells were punched into the MHA using a sterile cork borer of 6 mm diameter. The six NS dilutions were introduced into the wells aseptically, while the seventh well, serving as the control, was filled with an equal volume of 0.2% DMSO. All plates were allowed to diffuse under room temperature for 1 h according to the recommendations of the National Committee for Clinical Laboratory standards (NCCLS). All plates were incubated aerobically at 37 \({}^{\circ}\)C for 24 h in an upright position. Experiments were carried out in three replicates with zones of inhibition measured in millimeters (mm) 24 h post-incubation, and the results are presented as means \(\pm\) standard deviation.
## 3 Materials and Methods
### Data Preparation  
The data were transformed by grouping them into daily intervals, as they were originally in minutes. This was performed to condense the database and enable training and forecasting by day, instead of by minute. Similarly, data corresponding to incomplete days collected in the dataset at the beginning and end of it were discarded.  
Seventeen numerical variables from the original dataset were selected based on their relevance to the problem at hand. These variables were chosen because they are the most relevant to the research objective. The variables for electric consumption, current, and voltage are essential for understanding the current situation of the electrical grid, while the variables for temperature, pressure, and humidity help contextualize the environment and surroundings where the readings are being taken. A reduced number of variables simplifies the model and can facilitate the interpretation of the results. The selected variables are listed below:  
* _active_power_: This is the amount of electric consumption measured in watts per minute in the sensor reading over the specified time period.
* _current_: This is the amount of current measured in amperes in the sensor reading over the specified time period.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Date** & **Active\_Power** & **Current** & **Voltage** & **Reactive\_Power** & **Apparent\_Power** & **Power\_Factor** & **Temp** & **Feels\_Like** \\ \hline
5 November & 265.10 & 2.53 & 122.20 & 159.09 & 309.17 & 0.8575 & 24.19 & 23.68 \\
2022 14:05 & 265.10 & 2.53 & 122.20 & 159.09 & 309.  
* _voltage_: This is the amount of voltage measured in volts in the sensor reading over the specified time period.
* _temp_: This is the temperature measured in degrees Celsius in the sensor reading over the specified time period.
* _pressure_: This is the amount of atmospheric pressure measured in hectopascals in the sensor reading over the specified time period.
* _humidity_: This is the amount of absolute air humidity in the sensor reading over the specified time period.  
For the grouping or aggregation of the data, that is from minutes to days and based on the nature of the variables, sum or average operations were performed, as shown in Table 4.  
The variable named _active_power_ records the value of electric consumption in units of watts per minute. The daily consumption is computed by adding all the minute data registered during each day. The data were transformed into kilowatt-per-hour units, the unit used to measure electric consumption in Mexico. Thus, the variable formerly known as _active_power_ after this transformation has been designated as kWh.  
\[kWh=\frac{active\_power}{1000*60} \tag{8}\]  
The result was a dataset of 279 observations and six variables, where each observation corresponds to the value recorded over one day, covering a period from 6 November 2022 to 11 August 2023. Table 5 shows an example of the data after the transformations described in this section.
## 2 Background  
### Axial Line Analysis Computation  
To develop a method of drawing axial lines, several previous studies have suggested the use of all-line axial maps to show spatial configurations (e.g., [2; 3]). All-line axial maps are drawn from a set of vertex-to-vertex lines within a given space that do not intersect the wall lines or boundaries of that space [2; 3]. The rules for these maps are intuitive and allow the maps to be easily generated by computer programs. Thus, by following these mapping rules, this paper develops a method of axial line reductions for finding the minimal set of axial lines.  
There are, however, other approaches to generating axial maps (e.g., [4; 5; 6]). [PERSON] and [PERSON] [4] and [PERSON] and [PERSON] [5] used visual fields, isovists or polygons in given spaces to generate axial lines. These approaches relied on spatial division by polygons and focused on generating axial lines based on visibility, rather than reducing axial lines from the vertex-to-vertex lines of an all-line axial map. [PERSON] and [PERSON] [6] generated axial lines by using existing center lines in urban maps and layouts based on open-source maps. Although these approaches have proven useful for generating axial lines, they developed a new application unlike the reduction methods from all-line axial map that are used in well-known space syntax programs. Rather than developing a new application, this paper adapts an existing method for generating maps of all axial lines. Since this paper investigates a method for finding a minimal set of axial lines from all axial lines, [PERSON] and [PERSON]'s and [PERSON] and [PERSON]'s approaches are therefore outside the scope of this paper. Thus, this paper uses the method of generating all-line axial maps and reducing the axial lines of these maps to find their minimal sets of lines. This paper seeks to add an optimization perspective, which focuses on finding a fewest set, to other approaches for generating axial lines including those proposed by [PERSON] and [PERSON] [4], [PERSON] and [PERSON] [5] and [PERSON] and [PERSON] [6].  
Many previous studies on reducing axial lines have used a greedy backward elimination and a sub-set elimination. [PERSON] et al. [2] and [PERSON] et al. [3] demonstrated how to reduce axial lines in all-line maps for axial analysis. They used a greedy backward elimination and a sub-set elimination to reduce an all-line axial map to a simpler set of axial lines. The greedy and subset algorithms were required to examine every possible combination of lines. However, because these methods eliminated axial lines in a stepwise manner, they did not always result in a minimal set of axial lines. The results of these algorithms significantly depended on the manner of initiating the combinations for each set of axial lines and the manner of setting up the next procedure to select another axial line. Therefore, this paper seeks to find a holistic approach to identify a minimal set of axial lines.
###### Abstract  
In structural component applications the use of composite materials is increasing thanks to their optimal mechanical characteristics. However, the complexity of the damage evolution in composite materials significantly limits their widespread diffusion. Non-destructive tests are thus becoming ever more important. The detecting Damage Index (\(DI_{d}\)) technique has been recently brought in the realm of the non-destructive characterization tests for components made of composite material. In contrast to other techniques, this methodology allows to quantitatively assess local residual properties. In this paper, the \(DI_{d}\) technique is adopted in combination with the finite element method. The mechanical response of two composite plates (an 8-layer twill fabric carbon/epoxy) subjected to four-point bending test is firstly used to tune a finite element model of the laminate. Then, an undamaged laminate of the same composite material is progressively damaged through repeated four-point bending tests. Local residual elastic properties are mapped on the plate through the \(DI_{d}\) technique. A continuous polynomial curve has been considered to account for the variation of the elastic modulus in the finite element model. The resulting force-displacement curve of the numerical analysis is compared to experimental data of damaged plate, resulting in very good agreement. The combination of the experimental activity and the numerical finite element analysis points out the accuracy of the \(DI_{d}\) methodology in assessing local residual elastic properties of composite materials.  
Keywords:non-destructive tests; damage assessment; residual properties; Finite Element Method; Damage Index +
Footnote †: journal: Applied Mechanics and Physics