esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Literature Review
### Product Identity vs. Traceability: Conceptual Distinction  
In agricultural supply chains, the terms traceability and product identity are often used interchangeably. However, they represent distinct but complementary concepts that must be clearly differentiated to understand the value proposition of blockchain, Decentralised Identifiers (DIDs), and digital twins.  
Traceability refers to the ability to track the history, application, or location of a product as it moves through the supply chain [33]. This includes capturing data about inputs, processes, transportation, storage, and handling. Traditional traceability systems focus on the \"where\" and \"when\" of products, providing visibility into the supply chain flow for purposes such as quality control, recall management, and regulatory compliance [34].  
\"Traceability is primarily concerned with tracking and documenting the path a product follows from origin to end-user, typically through logistics and process data.\" [35].
## 4 Simulation Setup
### Evaluation Metrics  
Per-user SE is defined as follows:  
\[\text{SE}_{j}=\log_{2}(1+\text{SINR}_{j}).\]  
SE is measured in bits per second per Hertz (\(\text{bps}/\text{Hz}\)), based on the Shannon capacity formula; accordingly, the achievable data rate for user \(j\) is provided as follows:  
\[R_{j}=B\cdot\text{SE}_{j}\]  
where \(B\) is the system bandwidth. This metric quantifies how efficiently each user's channel can carry information under the given SINR conditions.  
\begin{table}
\begin{tabular}{l l} \hline \hline
**Parameter** & **Value** \\ \hline Number of APs (\(M\)) & 64 \\ Number of UEs (\(K\)) & 20 \\ System Bandwidth (\(B\)) & 10 KHz \\ Noise Power Density (\(N_{0}\)) & \(-174\text{ dBm}/\text{Hz}\) \\ Path Loss Model & \(\beta_{i,j}=\frac{1}{1+d_{ij}}\), where \(\alpha=3.76\) \\ Channel Model & Rayleigh fading \\ UE Distribution & Clustered in high-density regions \\ AP Transmission Power (\(P_{\text{AP,max}}\)) & 200 mW \\ CPU Transmission Power (\(P_{\text{CPU,max}}\)) & 10 W \\ Minimum SINR Threshold (\(\gamma_{\text{min}}\)) & 0 dB \\ CNN Training Epochs & 1000 \\ CNN Learning Rate & \(1\times 10^{-3}\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Simulation parameters.  
EE is calculated for each user as follows:  
\[\text{EE}_{j}=\frac{R_{j}}{P_{\text{total},j}}\]  
where \(P_{\text{total},j}\) represents the total power consumed to serve user \(j\), including both the CPU-to-AP and AP-to-UE power contributions [4]. This metric reflects how effectively power is used to support communication performance on a per-user basis. All metrics are evaluated at the per-user level and averaged across multiple randomized UE distributions to ensure statistically meaningful comparisons.
## 2 Results
### Monitoring algal Concentration during Rotifer-Grazing and Freeze-Thaw Experiments
#### 2.1.2 Freeze-Thaw Experiments  
Algal cell concentrations were likewise monitored daily, however chlorophyll-based fluorescence measurements, instead of direct enumeration via cell counting, was used for cultures of _M. gaditana_ exposed to three successive freeze-thaw cycles (abbreviated Freeze-Thaw Algae or FTA) (Figure 1D-F) and ESAW media blanks as a negative control. This alternative algal-density determination method was employed because with FTA Experiment 1, it was observed that direct enumeration was not a reliable way to determine the quantity of viable microalgal cells still present in the culture (data not shown). Thus, for those cultures undergoing the freeze-thaw process (Figure 1D-F, Cultures 4-6), time-dependent decreases in chlorophyll fluorescence signal relative to actively growing _M. gaditana_ cultures (Figure 1D-F, Cultures 1-3) were observed. Resulting FTA cultures displayed a rapid decrease in fluorescence signal compared to corresponding time-matched healthy algae cultures, on average displaying ~60% of the relative fluorescence signal after 6 h (Figure 1E,F) and less than 10% of the relative fluorescence signal after 24 h of growth and beyond (Figure 1D-F). For this reason, the experiments were ended after 48 h, instead of 96 or 120 h as for the A + R Experiments.
## 4 Manipulability Maximization and Constraints Satisfaction
### Joint Velocity Constraints
#### 4.3.1 Joint Velocity Boundary Constraints  
To satisfy joint velocity boundary constraints, the initial and final joint velocities must be zero. \(\mathbf{u_{p}}\) in (12) is directly associated with the end-effector's task; therefore, it implicitly satisfies the boundary constraints. However, \(\mathbf{u_{h}}\) in (12) does not necessarily satisfy them, because the manipulability maximization task is dependent on the mobile manipulator configuration at the initial and final poses. In this work, we propose using a time-varying self-motion magnitude to handle these constraints. The objective is to avoid non-zero values of \(\mathbf{u_{h}}\) only at the beginning and end of the trajectory. With this in mind, it is proposed to set the variation factor \(\beta(t)\) to increase from zero to one at the beginning of the trajectory, maintain a value of one for most of the trajectory, and then decrease from one to zero at the end of the trajectory.  
Let \(t_{b}\) be the blending time for \(\beta(t)\) to increase from zero to one, and \(t_{f}\) be the trajectory execution time. To achieve a smooth transition, a 5 th order polynomial \(\beta_{1}(t)=a_{0}+a_{1}t+a_{2}t^{2}+a_{3}t^{3}+a_{4}t^{4}+a_{5}t^{5}\) is used when \(t<t_{b}\). The decrement in \(\beta(t)\) at the end of the trajectory, when \(t>t_{f}-t_{b}\), is the complement of the polynomial \(\beta_{1}(t)\) and is defined by \(\beta_{2}(t)=1-\beta_{1}(t-t_{f}+t_{b})\). By imposing the conditions \(\beta_{1}(0)=0\), \(\beta_{1}(t_{b})=1\), \(\dot{\beta_{1}}(0)=0\), \(\dot{\beta_{1}}(t_{b})=0\), \(\dot{\beta_{1}}(0)=0\), \(\dot{\beta_{1}}(t_{b})=0\), the values of the coefficient of \(\beta_{1}(t)\) are found.  
After finding the polynomial coefficients, the self-motion magnitude variation factor is given by  
\[\beta(t)=\begin{cases}a_{3}t^{3}+a_{4}t^{4}+a_{5}t^{5},&\text{ if }t<t_{b}\\ 1,&\text{ if }t_{b}\leq t\leq t_{f}-t_{b}\\ 1-(a_{3}(t-t_{f}+t_{b})^{3}+&\\ a_{4}(t-t_{f}+t_{b})^{4}+&\text{ if }t>t_{f}-t_{b},\\ a_{5}(t-t_{f}+t_{b})^{5})&\\ \end{cases} \tag{24}\]  
with:  
\[a_{0}=0,\quad a_{1}=0,\quad a_{2}=0,\] \[a_{3}=\frac{10}{t_{b}^{3}},\quad a_{4}=-\frac{15}{t_{b}^{4}}, \quad a_{5}=\frac{6}{t_{b}^{5}},\]  
The blending time \(t_{b}\) is chosen by the user. Figure 3 shows the shape of \(\beta(t)\) for \(t_{f}=15(s)\), \(t_{b}=2.5(s)\).
## 3 Results and Discussion
### Thermogravimetric Analysis
The peak temperatures (dTGmax) represent the temperature at which the maximum rate of mass loss occurs during thermal degradation. The dTG peak temperature gradually increased from 287.8 to 320.5 \({}^{\circ}\)C for chitosan and from 392.4 to 443.5 \({}^{\circ}\)C for chitin, indicating thermal lag during carbonization. The residual weight left after the degradation at 1000 \({}^{\circ}\)C for chitosan and chitin were found to be in the range of 32.6-34.1 wt.% and 10.5-10.9 wt. %, respectively, at various heating rates. Clearly, chitosan yielded a higher char fraction than chitin when thermally degraded in a nitrogen atmosphere, primarily due to differences in chemical composition, molecular structure, and thermal degradation mechanisms. Chitosan, possessing a higher nitrogen content due to its increased number of amino (-NH\({}_{2}\)) groups compared with chitin, which contains more N-acetyl (-NHCOCH\({}_{3}\)) groups, facilitates the formation of cross-linked nitrogen-containing structures that enhance the stability of the carbonaceous char. The presence of nitrogen in the polymer backbone also promotes cyclization reactions and the development of thermally stable aromatic structures, thereby reducing the extent of volatile release while increasing char yield during carbonization. This can be explained by the presence of nitrogen in the polymer backbone, which favors cyclization reactions and the formation of thermally stable aromatic structures, reducing the extent of volatile release. Due to its higher degree of acetylation, chitin contains a greater proportion of N-acetylglucosamine units, which primarily decompose through extensive deacetylation and dehydration, leading to increased volatile release compared with chitosan. In contrast, chitosan, being partially deacetylated, undergoes carbonization with reduced deacetylation-driven mass loss, resulting in a higher retention of solid residue. Ultimately, chitosan's higher nitrogen content, lower degree of acetylation, enhanced cross-linking, and reduced volatile release collectively contribute to its higher char yield compared with chitin under identical carbonization conditions. Additionally, the formation of nitrogen-enriched aromatic structures reinforces the stabilization of the carbonaceous matrix, further promoting char retention in chitosan.
## 4 Methods
### Experimental Methods
#### 4.1.1 Anchorage Testing  
The element anchor system, previously discussed in Section 2.2, was experimentally investigated in this study. The main challenge associated with this system is such that the screw anchors should be embedded in a thin TRRPC facing (25 mm) all while being able to effectively transmit the horizontal forces from the sandwich element to the load bearing structure. The specimens (1360 \(\times\) 1220 mm) were designed as small-scale facade elements, according to that shown in Figure 5. The elements consisted of two 25 mm TRRPC facings set apart by a 150 mm layer of FC. Both facings contained two carbon textile grid layers, placed symmetrically in the center of the facings. The two TRRPC facings were connected by two lines of GFRP connectors in each specimen. Each test specimen was provided with two upper element anchor details and two lower element anchor details. The inner facing was strengthened locally by increasing the facing thickness to 70 mm at the position of the two upper element anchoring details, each consisting of two bolt anchors (M16 \(\times\) 140). The upper thickened sections were reinforced with one extra GFRP bar profile. The elements were also strengthened by a thicker section (70 mm) along the lower edge of the inner TRRPC facing, in which the two lower bolt anchors (M16 \(\times\) 140) were incorporated. Six specimens were manufactured, and each element anchor detail was used for a given test configuration.  
The shear load capacity tests of the anchor details were conducted using a servo-hydraulic testing machine. The shear load capacity related to the upper and lower element anchors was determined by four different test cases to account for positive and negative wind load: (a) positive shear load at upper anchors (\(H_{\text{up}}\)), (b) negative shear load at upper anchors (\(H_{\text{un}}\)), (c) positive shear load at lower anchors (\(H_{\text{lp}}\)) and (d) negative shear load at lower anchors (\(H_{\text{In}}\)). Schematic illustrations of the set-ups for the four different test cases can be seen in Figure 6. In the upper element anchor tests (cases a  
Figure 5: Illustration of the anchor tests specimens.  
and b), the shear load (\(H_{\text{up}}\) and \(H_{\text{un}}\)) was applied to a steel profile connected to the two bolt anchors. For the lower element anchors (cases c and d), the shear load (\(H_{\text{lp}}\) and \(H_{\text{ln}}\)) was applied directly to a threaded rod inserted in the bolt anchor. In test cases a and c, the specimens were placed directly on the laboratory floor, as for cases b and d, the specimens were placed on two supporting steel profiles. The load was applied using a displacement rate of 2.0 mm/min and was logged by a 100 kN rated load cell (accuracy greater than 1%).
## 3 Proposed Solution
### The Principle of Variable Polarization Modulation  
The proposed variable polarization modulation (VPM) technology is specifically designed for advanced satellite communication systems that require high security and robustness, such as military communications, government secure links, and next-generation  
Figure 5: Model of antenna array.  
satellite-to-ground data relays. These applications typically employ dual-polarized antennas capable of generating and receiving arbitrary polarization states, including linear, circular, and elliptical polarizations. By adaptively tuning the polarization state of the transmitted signal, they intelligently create an orthogonality to the polarization pattern of interfering signals. VPM technology precisely controls the amplitude ratio and phase difference of two orthogonal signals by assigning specific digital weighting factors to them. Then, it transmits the signals to a dual-polarization antenna, resulting in the generation of an electromagnetic wave with an arbitrary polarization state. Figure 6 illustrates the constellation diagrams of VPM. Figure 6a-h represent horizontal polarization, vertical polarization, 45\({}^{\circ}\) linear polarization, 135\({}^{\circ}\) linear polarization, right circular polarization, left circular polarization, right elliptic polarization and left elliptic polarization, respectively. The red dot indicates the corresponding polarization constellation point, and x, y and z denote the coordinate axes of three-dimensional coordinate system.
_Algorithms_**2013**, \(6\), 371-382; doi:10.3390/a6020371  
_algorithms_  
ISSN **1999-4893**  
www.mdpi.com/journal/algorithms  
**Improving Man-Optimal Stable Matchings by Minimum Change of Preference Lists \({}^{\dagger}\)**  
**[PERSON] \({}^{1}\), [PERSON] \({}^{2}\), [PERSON] \({}^{1}\), [PERSON] \({}^{3,*}\) and [PERSON] \({}^{4}\)**  
\({}^{1}\) Graduate School of Informatics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan; E-Mails: [EMAIL_ADDRESS] (T.I.); [EMAIL_ADDRESS] (K.I.)  
\({}^{2}\) School of Computing Science, University of Glasgow, Glasgow, G12 8 QQ, Scotland; E-Mail: [EMAIL_ADDRESS]  
\({}^{3}\) Academic Center for Computing and Media Studies, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan  
\({}^{4}\) Communication Service Group, Research and Development Center, Nippon Telegraph and Telephone West Corporation, 1-2-31 Sonezaki Kita-ku Osaka 530-0057, Japan; E-Mail: [EMAIL_ADDRESS]  
\({}^{\dagger}\) A part of this paper was presented at the 7 th Hungarian-Japanese Symposium on Discrete Mathematics and Its Applications (HJ 2011) and the 6 th Annual Meeting of the Asian Association for Algorithms and Computation (AAAC 2013).  
* Author to whom correspondence should be addressed; E-Mail: [EMAIL_ADDRESS]; Tel.: +81-75-753-7418; Fax: +81-75-753-7440.  
_Received: 27 December 2012; in revised form: 17 May 2013 / Accepted: 20 May 2013 / Published: 28 May 2013_  
**Abstract:** In the stable marriage problem, any instance admits the so-called _man-optimal stable matching_, in which every man is assigned the best possible partner. However, there are instances for which all men receive low-ranked partners even in the man-optimal stable matching. In this paper we consider the problem of improving the man-optimal stable matching by changing only one man's preference list. We show that the optimization variant and the decision variant of this problem can be solved in time \(O(n^{3})\) and \(O(n^{2})\), respectively, where \(n\) is the number of men (women) in an input. We further extend the problem so that we are allowed to change \(k\) men's preference lists. We show that the problem is W[1]-hard with respect to the parameter \(k\) and give \(O(n^{2k+1})\)-time and \(O(n^{k+1})\)-time exact algorithms for the optimization and decision variants, respectively. Finally, we show that the problems become easy when \(k=n\); we give \(O(n^{2.5}\log n)\)-time and \(O(n^{2})\)-time algorithms for the optimization and decision variants, respectively.  
**Keywords:** combinatorial optimization; polynomial-time algorithms; stable marriage problem; man-optimal stable matching
# Experimental Study on the Influence of Low Temperature on the Gas Permeability of Granite
## 2 Materials and Methods  
### Specim Preparation  
Two types of granite were selected for this study: a coarse-grained granite sourced from Hunan Province, China, and a fine-grained granite from Fujian Province, China. All rock specimens were machined into standard cylindrical shapes with a diameter of 50 mm and a height of 100 mm, in accordance with the specifications recommended by the International Society for Rock Mechanics (ISRM). To ensure specimen quality, the non-parallelism and surface flatness of the end faces were maintained below 0.02 mm, while the angular deviation from perpendicularity between the specimen axis and end faces was kept below 0.25\({}^{\circ}\). In addition to the standard specimens, a subset was fabricated into hollow cylindrical specimens by drilling a central hole with a diameter of 10 mm through the entire 100 mm height. The standard cylindrical specimens were used for freeze-thawcycling tests, whereas the hollow specimens were employed in real-time low-temperature testing, as illustrated in Figure 1.  
Before and after the freeze-thaw cycles, all specimens underwent saturation and drying procedures using a high-pressure vacuum saturator and a drying oven, respectively. The dry and saturated masses of the specimens were recorded before and after the tests to determine porosity changes. The basic physical parameters of the coarse- and fine-grained granites are summarized in Table 1. Mineralogical compositions were identified using X-ray diffraction (XRD) analysis, and the primary mineral constituents of both granite types are presented in Table 2 and Figure 2. The equipment used was a Malvern Panalytical third-generation Empyrean Sharp-Shooter X-ray diffractometer, with a scanning angle range of 5\({}^{\circ}\) to 90\({}^{\circ}\) and a scanning speed of 5\({}^{\circ}\) per minute.
## 2 Related Work  
[PERSON] _et al._[8] presented the need and importance of security in VANETs. In order to fulfill the security requirements, they proposed a security architecture which will provide security and privacy. VANETs depend on vehicle to vehicle communication, which allows a malicious node to send malicious data over the network. [PERSON] _et al._[9] proposed a technique to detect and correct the malicious data in VANETs. His technique is based upon the sensor data, collected by vehicles in the VANETs and neighbors information. Redundant information from neighbors and the position of vehicles help detect the malicious data.  
[PERSON] _et al._[10] proposed a scheme to localize and detect Sybil vehicles in VANETs on the basis of the signal strength. With the help of signal strength a vehicle can verify the position of other vehicles and eliminate the malicious nodes. [PERSON] first proposed position verification techniques with the help of signal strength but it still has some shortcomings _i.e._, spoof attacks are possible and data is inconsistent. In order to overcome this weakness, he proposed another solution to prevent malicious nodes in VANETs. Two static algorithms are proposed with the help of traffic patterns and base stations. These algorithms are designed to verify the position of the vehicle and reduce the effect of malicious nodes on communication in VANETs. The following benefits are achieved by using this algorithm:* Error rate is reduced
* Malicious nodes are easily detected
* It is not hardware dependent  
In order to improve performance, selfish or malicious nodes must be captured and removed from VANETs, but it is very difficult to detect these nodes due to the lack of infrastructure and the dynamic nature of VANETs compared to any other _ad-hoc_ networks. [PERSON] _et al._[11] also proposed a feasible framework adapted to the features of the vehicular environment. It detects and prevents the effects of malicious nodes in a VANET scenario.
# Joint Uplink and Downlink Resource Allocation for D2D Communications System
## 4 Numerical Analysis  
In this section, the performance of our proposed algorithm is demonstrated by numerical simulation results.
## 7 Simulation Results and Discussions
### Transient Stability Analysis
#### 7.1.2 Analysis Using the Proposed Rotor-Side Controller  
Two cases are considered using the proposed rotor-side controller shown in Figure 6. The power rating of each wind generator in Case 01 is DFIG = 28 MW and SCIG = 72 MW (total: 100 MW), and, in Case 02, DFIG = 27 MW and SCIG = 73 MW (total: 100 MW).  
Figure 23(a,b) show the responses of reactive powers, which indicate that the DFIG can provide the necessary reactive power during the severe symmetrical 3 LG fault in Case 01. As a result, the connection point voltage quickly recovers to the rated value in Case 01, as shown in Figure 24(a). However, in Case 02, the DFIG does not provide the necessary reactive power during the fault condition, and thus, the connection point voltage cannot be back to the rated value. Since the connection point voltage does not satisfy the standard grid code of Figure 16 in Case 02, the WF is disconnected from the power system by opening CBs near bus 12 at 2 s. The rotor speed responses of both wind generators are stable in Case 01, but unstable in Case 02, as shown in Figure 26.  
Figure 23: Frequency responses of the power system.  
Figure 22: Individual responses of conventional SGs: (**a**) active power; (**b**) rotor speed.  
Figure 27 shows the active power output of DFIG and SCIG, respectively. The active power can recover to the nominal value in Case 01 for both wind generators, but failed to recover to the nominal value in Case 02. Moreover, the DC-link voltage of the DFIG becomes more stable in Case 01, as compared to Case 02, as shown in Figure 28a. Figure 29a,b show the active power output and rotor speed responses, respectively, of the conventional power plants (SGs). The active power and rotational speed of the SGs can return to the initial condition in Case 01. However, the active power of the SGs in Case 02 increases significantly after the WF has been disconnected, resulting in a rotor speed drop of the SGs. It is clear that the system becomes unstable in Case 02, which can also be seen from Figure 30, where the system frequency collapses in Case 02 after the WF has been disconnected.  
Figure 27: Active power output of wind generators: (**a**) DFIG; (**b**) SCIG.  
Figure 25: Individual response of the WF at bus 12: (**a**) Voltage at connection point; (**b**) total active and reactive power at connection point.  
Therefore, the lowest power rating of the DFIG with the proposed rotor-side controller is 28 MW in order to stabilize the 72 MW SCIG. The DFIG can also stabilize the SGs. Finally, the reactive power output of DFIG (capacity is 28 MW) for both proposed and conventional rotor-side controllers is depicted in Figure 31. The reactive power output for the proposed FLC-controlled DFIG is larger and more efficient than the conventional PI-controlled DFIG.  
Figure 28: Individual responses of the DFIG: (**a**) DC-link voltage; (**b**) reactive power output of GSC.  
Figure 30: Frequency responses of the power system.  
Figure 29: Individual responses of conventional SGs: (**a**) active power; (**b**) rotor speed.