esa-sceva/satcom-chunk-collection huggingface dataset:
# Multi-Robot Formation Control Based on CVT Algorithm and Health Optimization Management
## 6 Summary and Outlook  
This paper proposes a multi-robot formation control and health optimization management method based on the CVT algorithm, which has outstanding advantages compared with the traditional multi-robot formation algorithm.  
Figure 23: Multi-robot dynamic formation experiment in a narrow channel: (**a**) \(t_{1}=0\) s; (**b**) \(t_{2}=48\) s; (**c**) \(t_{3}=61\) s; (**d**) \(t_{4}=207\) s.  
Figure 22: Multi-robot dynamic formation experiment with random obstacles: (**a**) \(t_{1}=0\) s; (**b**) \(t_{2}=32\) s; (**c**) \(t_{3}=80\) s; (**d**) \(t_{4}=102\) s.  
1. The algorithm converges one robot to the center of mass of each Voronoi unit, which avoids collisions between robots to the greatest extent, making the multi-robots form the desired formation at the specified position according to the optimal distribution and proving the related theories.
2. Taking into account the existence of obstacles in the environment, by reducing the value of the density function of the obstacle position the robot can avoid the obstacle, improving the collision avoidance ability of the robot.
3. The health optimization management algorithm was used to maximize the endurance of unhealthy robots and improve the stability and robustness of the unhealthy robots under the premise of minor changes in the original framework. At the same time, the insertion construction method was introduced to make the robots in the formation more efficient. This enables a better response to changes in the environment.
4. In the simulations and experiments, through experimental verification using the MATLAB simulation platform and the ROS robot platform, it was verified that the method proposed in this paper can ensure that the robot can form the required formations according to the optimal distribution. In the designated area, the structural redundancy and internal carrying capacity of the multi-robot system were increased, and the formation was dynamically switched according to the external environment. At the same time, the health of the robots was better optimized and managed, which improves the flexibility and robustness of the formation.  
In future work, formation control in more complex obstacle environments will be considered. When applied to heterogeneous groups with different performance and motion models, the method proposed in this paper will be more versatile and robust. These applications will continue to be studied in future work.  
Conceptualization, K.C. and S.G.; Methodology, Y.C. and S.G.; Resources, H.D.; Software, K.C. and H.Z.; Supervision, S.G.; Writing--original draft, K.C. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Shaanxi International Science and Technology Cooperation Project grant number [2019 KW-014] and Xi'an Technological University abroad funding grant number [2019001].  
Not applicable.  
The authors declare no conflict of interest.
## 2 Theoretical Background
### Power Grid: FDI and Parameter Attacks  
The power grid can be modeled through nodes and edges. Measurements collected from the grid are power flows into those edges (lines) and injections into the nodes. SE reads off those measurements and uses a model that is based on the connectivity of the nodes and the electrical characteristics of the lines (system database). Hence, SE is a monitoring tool to observe the healthiness of the power grid over time. Therefore, the attacks pertaining to the power grid could affect the collected measurements or the database used by SE. FDI attacks can be on measurements or databases [31]. Attack types result in different residual characteristics and patterns [17]. These will be used here for the correction. This work [32] was used towards parameter cyber-attack correction, while [33] is used for measurement FDI attack correction.
# A Cyanobacteria-Based Biofilm System for Advanced Brewery Wastewater Treatment
## 2 Materials and Methods
### Culture Identification and Inoculum Preparation  
Microbial samples were collected from the secondary settling tank of the wastewater treatment plant of Patras University's and were cultivated autotrophically in a nutrient medium (containing (in mg.L\({}^{-1}\)) KNO3, 200; MgSO4\(\cdot\)7H2O, 100; CaCl2\(\cdot\)2H2O, 50; K2 HPO4, 108; KH2 PO4, 56) suitable for algae/cyanobacteria enrichment [31]. The samples were cultivated for approximately 30 days under constant illumination of 2000 lux (or 27 \(\upmu\)mol m\({}^{-2}\) s\({}^{-1}\)) provided by two cool white lamps (Phillips, 120 cm, 36 W), without any mechanical air supply. Temperature ranged between 24 and 26 \({}^{\circ}\)C and pH gradually rose from 7 to 9.  
After the initial cultivation period, a microbial consortium consisting of mixotrophic aggregates was obtained. Samples of the microbial culture were placed in sedimentation chambers and, using phase contrast and epifluorescence microscopy (Nikon Eclipse SE 2000 microscope), two cyanobacterial species were identified. _Leptolynygbyus_ sp. filaments in aggregate form dominated the culture (relative biomass fraction: 85%), while a second _Chroococcus_-like population (relative biomass fraction: 5%) was also identified. The culture also contained a significant number of heterotrophic bacteria and protozoa (relative biomass fraction: 10%). Microbial population percentages are expressed as fractions of the total biomass of the microbial community, including cyanobacteria filaments and large-sized heterotrophic bacteria (1-2 \(\upmu\)m) [4; 5]. The culture was then acclimatized in the brewery wastewater (Section 2.1), under agitation and the conditions described above, without any significant alterations in microbial population composition. This culture was used as an inoculum for all experiments when in the mid-exponential growth phase (biomass concentration of 300 mg.L\({}^{-1}\)).
## 5 Twinning the IFC-Based 4D Construction Management Information Model into Graph Database
Therefore, it is feasible and reasonable to adopt the graph database to store and twin the IFC-based information model. All the procedures are realized in Neo4j, which is a popular Java-based graph database [57]. There is a round-trip mechanism between the IFC files and the graph database. Twinning the IFC files to the graph database. This paper will use Java to twin the IFC information model into the graph database. The process is divided into the following six steps. Step1. Using IFC Java Toolbox to parse IFC files. The IFC Java Toolbox consists of three main parts: obtaining the Java class by parsing the IFC entity type, obtaining the Java type by parsing the IFC data content, and providing the object model IfcModel for IFC data to access. Step 2. Based on IFC schema, constructing a dictionary of the IFC entities and its key-value is corresponding to IFC entities' attributes;  
Step 3. Specify the database path and create an EmbeddedGraphDatabase instance under the path;  
Step 4. Generate the Node instance corresponding to the IFC entity through the designed createNode() method, and the information in the IFC entity is stored in the node's properties through the key-value set by the dictionary;  
Figure 8: Entities reference relationship in an IFC file. Figure 9: Graph database. Step 5. Create the relationship between nodes, which is the relationship between IFC entities, through the designed createRelationship() method. Step 6. Accessing the graph database using Cypher command. Therefore, an automatic algorithm to twin the IFC-based 4D construction information model to the Neo4j graph database is realized and the database can be used as a platform for participants to interoperate the construction information. Specifically, users can twin the IFC-based 4D construction information model to Neo4j, and the graph database-based information model can be uploaded to the cloud for all project participants to use. Project participants can fetch, modify, and update all the construction information they need through simple operation  
_Re-exporting the IFC files from the graph database._ This part is used to re-export the IFC files from the graph database to complete the round-trip between the IFC files and the graph database. Although the construction information has good interoperability when it is twinned and stored in the Neo4j-based graph database, users sometimes need the IFC files with updated information to further utilize information in various BIM software. Therefore, an algorithm is developed in this paper, which can re-export the IFC information in the graph database into a complete IFC file. This algorithm's core is to traverse the entire graph database's information and output it into an IFC file. The output IFC files can be used in different BIM software which supports the IFC format.
# A Novel Mobile Communications Authentication Scheme with Roaming Service and User Anonymity
## 7 Conclusions  
This study proposes an elliptic-curve-based authentication scheme with roaming service and user anonymity for mobile communication. It overcomes the weaknesses of [PERSON]'s scheme [PERSON] (2006) and  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Sender** & **Receiver** \\ \hline V1: MU calculates X = xP and EC = aP\({}_{\text{FA}}\) = abP & V2: FA calculates Y = yP and EC = bA = abP \\ V2: FA calculates MAC\({}_{\text{FA}}\) & V3: HA calculates MAC\({}_{\text{FA}}\) \\ V3: HA calculates MAC\({}_{\text{HA}}\) & V4: FA calculates MAC\({}_{\text{HA}}\) \\ V4: FA calculates sk\({}_{i}\) = xY and c\({}_{2}\) & V5: MU calculates sk\({}_{i}\) = xY and c\({}_{2}\) \\ \hline \hline \end{tabular}
\end{table}
Table 4: Balanced calculation of the session key.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Secure Item** & **[PERSON] (2006)** & **[PERSON] et al. [PERSON] et al. (2006)** & **[PERSON] (2004)** & **Our Scheme** \\ \hline Resist internal attack & Yes & No & No & Yes \\ Resist replay attack & No & Yes & Yes & Yes \\ Resist distributed denial-of-service attack for specific object & No & Yes & Yes & Yes \\ Achieve a high level of anonymity & No & No & No & Yes \\ Session key providing anonymity and authentication & No & No & No & Yes \\ Balanced calculation of the session key & Yes & No & No & Yes \\ \hline \hline \end{tabular}
\end{table}
Table 5: Comparison with related works.  
provides balanced session key computation in the authentication phase. We use an elliptic curve in the calculations, and therefore, the security performance is good. Although our computational complexity is comparable to that of [PERSON]'s scheme, our scheme reduces the load of MU calculation by moving this calculation to the HA, which has better computing performance. Finally, the advantages and weaknesses of our scheme are compared with those of other related works, and it demonstrates improved security, anonymity, and resistance to attacks without having additional computational complexity.  
This work was supported by MOST 105-2221-E-145-002.  
[PERSON], [PERSON] and [PERSON] conceived and designed the experiments; [PERSON] and [PERSON] performed the experiments and analyzed the data; [PERSON] wrote the paper.  
The authors declare no conflict of interest.
## 3 Data and Methodology
### Explanatory Variables  
Building on the literature review, this study selects explanatory variables from three dimensions, socioeconomic and transportation accessibility, land-use characteristics, and streetscape features, corresponding to regional, neighborhood, and street-level scales.
# IEEE 802.11 ah: A Technology to Face the IoT Challenge
## 3 Comparative Analysis of IEEE 802.11 ah with Previous IEEE 802.11 Amendments
### Comparison of IEEE 802.11 Amendments Based on MAC Features
#### 3.1.8 Block Acknowledgement (Block ACK)  
This mechanism enables the transmission of a single ACK frame by the station that received series of frames. This fact results in efficient use of airtime as compared to traditional positive ACK sent for every received frame.  
* _For IEEE 802.11n:_ Block ACK method is modified to support multiple MPDUs in an A-MPDU. The sender only resends the MPDUs that have not been correctly received by the receiver and are not acknowledged by it.
* _For IEEE 802.11 ah:_ Block ACK response includes the preferred MCS and the bandwidth information. IEEE 802.11 ah also introduces the fragment Block ACK procedure. Fragments obtained from the partition of a MSDU can be acknowledged either using immediate acknowledgement by responding with NDP Block ACK frames, or following the normal Block ACK procedure.
# Real-Time Optimization of RISC-V Processors Based on Branch Prediction and Division Data Dependency
## 4 Experiment and Result Analysis
### Stage Experiments and Result Analysis
#### 4.2.2 Division Instruction Simulation and Analysis  
We implemented the data dependency judgment module for division operations using Verilog code and integrated it into the Rev-riscv processor. The implementation was performed on an FPGA, and we used Vivado to observe the resource consumption before and after the addition of the module. The resource consumption is shown in Table 8.  
We used ModelSim to perform simulation tests on the processor with the added division data dependency module. Before the optimization of the division module, a single division operation required 33 clock cycles, during which the PC value was pausued for 30 clock cycles, as shown in Figure 12.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Serial**} & **Number of** & **Number of** & **Prediction** & **Average** \\  & **Branch** & **Correct** & **Accuracy** & **Accuracy** \\  & **Instructions** & **Branches** & **Accuracy** & **Accuracy** \\ \hline
1 & 140,791 & 103,904 & 73.8\% & \\
2 & 140,489 & 101,714 & 72.4\% & \\
3 & 140,852 & 105,076 & 74.6\% & \\
4 & 140,981 & 101,365 & 71.9\% & \\
5 & 141,254 & 102,409 & 72.5\% & \\
6 & 141,685 & 108,956 & 76.9\% & \\
7 & 140,756 & 104,441 & 74.2\% & \\
8 & 140,951 & 103,458 & 73.4\% & \\
9 & 140,501 & 105,797 & 75.3\% & \\
10 & 140,684 & 104,950 & 74.6\% & \\ \hline \hline \end{tabular}
\end{table}
Table 7: Accuracy of the simplified branch history predictor (SLBHP).  
Figure 12: Original divider module function simulation diagram.  
After optimizing the division data dependency, in the least ideal conditions, a single division operation consumes six clock cycles at 50 M, as shown in Figure 13.  
Under the most ideal conditions, division calculations no longer require the pipeline to pause.  
By optimizing the processor for data dependencies, the time required for division operations can be reduced from 33 clock cycles to 6 clock cycles, with the PC value needing to pause for only 5 clock cycles. Under the most ideal conditions, division calculations no longer require the pipeline to stall. The reduction in the time required for division calculations exceeds 75%.  
In summary, by adding the division data dependency module, the overall resource usage increases by approximately 9.1%, while the division calculation time is reduced by more than 75%.
## 2 Background and Related Work
### Analysis Security Testing
#### 2.2.3 Interactive Analysis Security Testing  
Interactive analysis, the ability to monitor and analyze code as it executes, has become a fundamental tool in computer security research. Interactive analysis is attractive because it allows us to analyze the actual executions, and thus can perform precise security analysis based upon runtime information. IAST tools are white box tools and they are an evolution of the SAST tools [39]. They allow code analysis, but unlike the SAST tools, they do it in real time and in an interactive way similar to the DAST tools. The main difference is that the tool runs directly on the server and has to be integrated into the application. Therefore, it is recommended to have a testing environment to perform all the tests and detect the greatest number of vulnerabilities. They are based on the execution of an agent on the server side. This agent is responsible for monitoring the behavior of the application being integrated into all layers of it, providing a broader control of the application flow and data flow, creating possible attack scenarios. The main characteristics of IAST tools are [40]:  
* It runs on the server as an agent, obtaining the results of the behavior generated by the end user on the published application. As they are agents that run on the server side, they must be compatible in the language that the application is designed. They can produce a relative runtime overhead in the application server.
* They can allow the sanitization of the entries, making the information that comes from the client side clean, eliminating possible injections or remote executions.
* The data correlation between SAST and IAST tools is usually more accurate as they are white box tools.
* They generate fewer false positives and they are not be able to detect client-side vulnerabilities.  
One of the techniques used by IAST tools is taint analysis. The purpose of dynamic taint analysis is to track information flow between sources and sinks. Any program value whose computation depends on data derived from a taint source is considered tainted. Any other value is considered untainted. A taint policy determines exactly how taint flows as a program executes, what sorts of operations introduce new taint, and what checks are performed on tainted values [41; 42; 43; 44; 45; 46; 47]. Another technique used by IAST tools is symbolic execution. It allows the analyses of the behavior of a program on many different inputs at one time, by building a logical formula that represents a program execution. Thus, reasoning about the behavior of the program can be reduced to the domain of logic. One of the advantages of forward symbolic execution is that it can be used to reason about more than one input at once [48; 49; 50; 51].
## 3 Solution Approach  
In the studies on the MCVRP solution algorithm, the VNS algorithm has shown a strong optimization ability [36; 37; 38; 39]. In addition, through a large number of experiments and the comparison of various algorithms in the early stage, it was found that the VNS algorithm is superior in the solution process and the TA algorithm is superior in the solution acceptance process. Finally, the VNS algorithm and TA algorithm are selected to design the solution algorithm of this study. The results mainly present the effectiveness analysis of the improvement before and after the algorithm design. The large number of experiments in the early stage will not be carried out here.  
In this section, based on the respective advantages of the VNS algorithm and the TA algorithm, a two-stage VNS-TA algorithm is designed to solve the mathematical model of MCVRP considering traffic congestion under the mixed carbon policy. The advantages of the VNS algorithm are fewer parameters, fewer links and easy operation and improvement [42]. The advantages of the TA algorithm are high efficiency and adaptive change [43]. The specific algorithm is designed as follows.  
In the stage of initial solution generation and pre-optimization, the scanning method is first used to generate the initial solution. Then, the local search process is performed to pre-optimize the initial solution. Finally, the stopping criterion of the maximum number of iterations is applied to generate a better pre-optimized initial scheme. In the re-optimization stage, the VNS-TA algorithm is designed to improve the pre-optimized initial scheme. First, five improved neighborhood structures are designed based on traditional neighborhood search operators, which promote the disturbance and neighborhood variability of the algorithm. Second, the neighbor path selection mechanism is designed, and the local search operators are combined to perform an efficient local optimization of the neighborhood solution. The local optimal solution can be obtained through this procedure. Then, the TA algorithm is embedded into the VNS algorithm, and the tolerance coefficient of the phased decline is designed to realize the gradual and slow reduction of the threshold acceptance range. This design appropriately accepts poor-quality solutions, expands the search range of the solution space and balances the search depth and search breadth of the VNS algorithm. Finally, the re-optimized scheme is output after a certain number of iterations.  
For ease of understanding, the word \"scheme\" is used in the algorithm output, such as in the phrases \"initial scheme\" and \"re-optimized scheme\". The term \"solution\" is used during the operation of the algorithm, such as in the phrases \"initial solution\", \"current solution\", \"current optimal solution\", \"neighborhood solution\", \"local optimal solution\" and \"global optimal solution\".
# Numerical Investigation of Jet Angle Effect on Airfoil Stall Control
## 3 Results and Discussion
### Static Airfoil Simulations
#### 3.1.1 Baseline (No Flow Control)
For the current flow condition, the accelerated flow near the leading edge may improve the SA RANS prediction on the separation. Figure 3: Comparison of the current simulation to the experiment [36] and the SA RANS simulations [19; 37] of the clean OA209. \(Ma=0.3\), \(Re=1.15\) M.  
The current slot width \(w_{jet}/c=0.1\%\) yields a negligible impact on the aerodynamic loading without jet actuation, as shown in Figure 6. The open outlet on the suction side is about 0.1%c and 0.27%c for the chord-normal and the tangential slot, respectively. Since the larger outlet with the tangential slot does not change significantly the baseline aerodynamics, the impact of the chord-normal slot by itself on the baseline would be much smaller. Since the small outlet of the slot on the suction side does not significantly change the baseline aerodynamics, the two distinct grids (one for the clean airfoil and the other for the slotted airfoil) can be used to check the sensitivity of the current computation to the spatial resolution. The slotted airfoil grid of \(1150\times 158\) (external flow part) includes much finer grids in the streamwise direction on the suction side, compared to the clean airfoil grid of \(420\times 150\). The boundary layer separates near the refined region downstream of the jet outlet at angles slightly beyond the stall angle. Figure 6 indicates that the current clean airfoil grid is fine enough for this stall simulation. This is expected because very similar grids have shown well-converged results with respect to the spatial resolution in aeronautic stall computations using second-order-accurate flow solvers [21; 23; 47]. Figure 4: Comparison between experimental data [36] and the current simulation of the OA209. \(Ma=0.3\), \(Re=1.15\) M.  
Figure 5: A supersonic pocket near the leading edge at three selected angles.