esa-sceva/satcom-chunk-collection huggingface dataset:
# Real-time Conflict Resolution Algorithm for Multi-UAV Based on Model Predict Control
## 4 Conflict Resolution Algorithm Based on DNMPC
### Performance Indicators for Conflict Resolution  
When executing tasks in airspace without threats, UAVs should fly along their own line with the mission in order to complete the mission as quickly as possible. Therefore, in the conflict resolution problem, the UAV should adjust its trajectory as little as possible while meeting the collision avoidance requirements [22]. In this paper, the normalized performance indicators are designed as follows:  
1. Total flight distance indicator: \[\begin{array}{c}\text{dis}_{i}=\left\|x_{i}(k)-x_{it},z_{i}(k)-z_{it}\right\| _{2}\\ J_{i1}(k)=\sum\limits_{i=1}^{N_{V}}(dis_{i}/dis_{0})=\sum\limits_{i=1}^{N_{V}}( \left\|x_{i}(k)-x_{it},z_{i}(k)-z_{it}\right\|_{2}/\left\|x_{i}(0)-x_{it},z_{i} (0)-z_{it}\right\|_{2})\end{array}\] (7) where, \(P_{ti}=[x_{it},z_{ti}]\) represents for the target of UAV \(i\).
2. Trajectory adjustment cost indicator: \[\begin{array}{c}c_{i}(k)=\left|\psi_{i}(k)-\psi_{i}(k-1)\right|/\left|\psi_ {i}(k-1)\right|+\left|v_{i}(k)-v_{i}(k-1)\right|/\left|v_{i}(k-1)\right|\\ J_{i2}(k)=\sum\limits_{i=1}^{N_{V}}c_{i}(k)\end{array}\] (8)
3. Conflict penalty function: Rewrite Constraint (5) as a penalty function for conflict: \[\begin{array}{c}\text{f}_{i}(\text{k})=\sqrt{\left[x_{i}(k)-x_{j}(k)\right] ^{2}+\left[z_{i}(k)-z_{j}(k)\right]^{2}}-r_{safe}\geq 0\\ \text{F}_{i}(\text{k})=\begin{cases}0&\text{f}_{i}(\text{k})\geq 0\\ \left|\text{f}_{i}(\text{k})\right|&\text{f}_{i}(\text{k})<0\end{cases}\end{array}\] (9)  
Figure 6: Synergetic heading angle control rule.  
In summary, the entire performance indicator for conflict resolution in period \([k,k+N]\) can be given as:  
\[\min_{\mathbf{U}_{i}}J_{i}=\sum_{q=1}^{N_{k}}\left[J_{i1}(k+q)+J_{i2}(k+q)+\rho \cdot\mathrm{F}_{i}(\mathbf{k})\right] \tag{10}\]  
where, \(\mathrm{F}_{i}(\cdot)\) is the conflict penalty function and \(\rho\) is the coefficient for the penalty function.
## 3 Numerical Validation Examples
### Six-Story Shear Building  
The proposed BMUA is validated using a different number of modes in Section 3.1.1 under a healthy structural state. Then, damage detection is conducted by the proposed BMUA in Section 3.1.2. In addition, the performance of the proposed and traditional BMUA is compared in terms of updating mass and stiffness. Finally, the probabilistic curves of possible damage are plotted in Section 3.1.3.  
The shear building sketch is shown in Figure 2, modeled as a six-DOFs structure with a total height of 30 m. Let us assume that the shear building has a Young's modulus of 69 GPa and mass density of 2700 kg/m\({}^{3}\). The length and width of each floor are both 0.3 m, with 0.082 m thickness. The column has the length and moment of inertial of 5 m and 0.0018 m\({}^{4}\), respectively. Therefore, the mass per floor and inter-story stiffness are estimated as M\({}_{j}=20\) kg (\(j=1,\,2,\cdots,6\)) and K\({}_{j}=12,000\) kN/m (\(j=1,\,2,\cdots,6\)), respectively, to mimic laboratory conditions. Note the design of floor mass and stiffness is realistic and achievable in a laboratory-scale shear structure [61]. Therefore, this example gives six mass/stiffness parameters to be updated. Let us suppose that the shear building under laboratory condition requires retrofits to increase inter-story stiffness and reduce lateral displacement due to long-term use; the original structure (Figure 2a) also needs to be updated to detect structural abnormality. The curved damper (Figure 1b) has superior performance to enhance stiffness and reduce inter-story drift. In addition, the curved damper is practically convenient and it can be easily implemented on structural maintenance [44].  
Thus, two curved dampers at each floor are installed to create a modified system, as shown in Figure 2b. In this example, assuming that each floor is provided with the equivalent stiffness modification of \(\Delta k_{j}=420\) kN/m (\(j=1,\,2,\cdots,6\)) by the curved dampers, the weight of each curved damper is ignored. It is noted that, although the damping ratio is changed due to the curved dampers (energy dissipation is improved), it has no influence on the performance of the proposed approach; because the damping ratio is not required, only natural frequencies and mode shapes are used to update the model. Hence, the FE model is updated by two groups of simulated measured data acquired from original and stiffness-modified systems. Gaussian white noise with zero-mean and a 1% coefficient of variation (COV) is considered on the measured data. Note that the value of 1% could reflect real noise level in practice based on the uncertainty identification of modal parameters by the Bayesian modal analysis [53; 62].
# Future Perspectives for Gamma-ray Burst Detection from Space
## 12 Theseus
### Instruments' Design  
Three instruments are planned on-board THESEUS. The Soft X-ray Imager (SXI) uses lobster-eye wide-field (\(\sim\)0.5 sr) focusing optics to increase the mission's sensitivity to fast transients in the 0.3-5 keV energy band. The use of such optics provides uniform sensitivity across a very large field of view while maintaining arcminute localization accuracy. The X- and Gamma-ray Imaging Spectrometer (XGIS) is a GRB and transient monitor providing an unprecedented combination of an exceptionally wide energy band (2 keV-10 MeV), imaging capabilities, and location accuracy. The latter achieves \(<\)15 arcmin up to 150 keV over an FoV of 2\(\pi\). The instrument is also characterized by an energy resolution of a few hundred eV at energies \(<\)30 keV and a time resolution of a few \(\upmu\)s over the whole energy band. Finally, the Infra-Red Telescope (IRT) is mainly conceived to detect, identify, and measure the redshift of GRB afterglows detected by the SXI and the XGIS, especially those at high redshifts (\(z>6\)). The IRT is a 70 cm Korsch telescope, optimized for an off-axis line of sight (LoS) of 0.884 deg. The optical design will implement two separated FoVs, one for photometry with a minimal size of 15 \(\times\) 15 arcmin (potentially extendable to 17 \(\times\) 20 arcmin) and one for spectroscopy of 2 \(\times\) 2 arcmin. On the photometric field of view, the IRT will be able to acquire images using five different filters (I, Z, Y, J, and H) and, on the spectroscopic field of view, will provide moderate resolution (R\(\sim\)400) slit-less spectroscopy in the 0.8-1.6 \(\upmu\)m range.
## 3 Principals of Routing Protocols and Their Breakdowns
### Energy Aware Multi-Path Routing Protocols
#### 3.1.2 \((U-ACH)^{2}\)  
The authors in [25] proposed a modified terrestrial-based protocol, namely away cluster head with adaptive clustering habit \((ACH)^{2}\). The authors modified the terrestrial protocol for a 3D underwater environment. They considered three typologies: a single sink and multiple sinks at the water's surface, and finally, a sink on the surface and underneath the water of WSN protocols such as low energy adaptive clustering hierarchy LEACH, distributed energy-efficient clustering (DEEC), threshold sensitive energy efficient sensor network protocol (TEEN), and stable election protocol (SEP). Here \"U\" can be replaced with any of the four protocols mentioned. The nodes form a cluster after being deployed, where the CH is chosen based on residual energy and the distance between the node and sink; this is performed to balance the network's load. The technique requires location, which is acquired through the Hello packet. The authors consider the dead node situation. If there is a dead node, the protocols simply choose a different route to deliver the packet. The simulation results were compared to depth-based routing (DBR) and energy efficient depth-based routing (EEDBR).  
The simulation shows that the proposed protocol performs better than DBR and EEDBR in load balancing, packets delivery ratio, and network performance. However, the cost of deployment for the above protocols is very high and is not realistic.  
Figure 3: Taxonomy of energy-based routing protocols for UWSN.  
* Comparison: Here, we compared both protocols. CTP-SEEC does not receive a Hello packet, whereas \((U-ACH)^{2}\) uses it but does not need localization while the former needing localization and both protocols use depth when selecting the forwarding node. \((U-ACH)^{2}\) has multiple sinks, and CTP-SEEC has only one sink at the water's surface. The simulation of this was performed using MATLAB simulation software. In Table 2, we compare the reactive routing protocols.
* Proactive Routing Protocols Every node in a network that uses a proactive routing protocol has one or more tables that describe the network's overall topology. These tables are updated regularly to ensure that each node has the most up-to-date routing information. Topology information must be sent between nodes frequently to maintain up-to-date routing information, resulting in a somewhat significant network overhead. On the other hand, routes will be accessible on-demand at all times. A proactive approach to UWSN routing aims to keep topology knowledge current. Thus, all nodes should be aware of the whole network in principle.
## 7 Conclusions  
Based on the actual engineering background of the pneumatic DTH hammer drilling, this study researched the vibration-damping method for the internal circuit unit of the near-bit MWD. The following conclusions can be drawn:  
1. Aiming at the high-intensity and low-frequency vibration problems faced by a near-bit MWD in a pneumatic DTH hammer drilling technology, a vibration-damping system design method was innovatively proposed. The method has a certain adaptive ability. It can achieve an optimal vibration-damping effect throughout the drilling process.
2. Through the modeling analysis and parameter optimization of the vibration characteristics of a drill string near a drill bit, the vibration-damping device based on the parallel connection of multiple spring-damper elements was innovatively designed. Its effectiveness was verified through the use of vibration simulation experiments involving a DTH hammer. The experimental results show that, in the vibration frequency range of 5-20 Hz and a vibration level range of 10-40 g, the vibration-damping device can achieve a peak vibration attenuation rate of more than 86.446% for the circuit unit and an improvement rate of more than 75.214% in terms of system vibration stability. The device significantly improves the vibration-damping performance in the drilling process.
3. The experimental results show that the vibration-damping device attenuates the peak vibration of the circuit unit by 94.8165% and improves the system vibration stability by 84.053% under normal drilling operations. Under extreme conditions, the vibration peak attenuation rate is 90.9384%, and the system vibration stability enhancement rate is 89.413%.  
In summary, this study provides an effective vibration-damping solution for a near-bit MWD in a pneumatic DTH hammer drilling and develops a vibration-damping system design method. This has a wide range of engineering applications. It is of great significance for improving the stability and service life of MWD.  
This research received no external funding.  
Not applicable.  
Data Availability Statement: Data are contained within the article. The data that support the findings of this study are available from the corresponding author, [PERSON], upon reasonable request.  
The authors would like to express their appreciation to [PERSON], who provided the experimental instrument for this research work.  
The authors declare no conflicts of interest.
## 3 Theoretical Comparisons Between Estimators
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \(\omega\) & \multicolumn{4}{c}{2} & \multicolumn{4}{c}{4} & \multicolumn{4}{c}{6} \\ \hline \(\hat{\alpha}^{PIG-MKLE}\) & **6.495** & **1.266** & **1.104** & **0.990** & **7.590** & **1.687** & **1.264** & **1.007** & **9.165** & **1.832** & **1.478** & **1.011** \\ \hline \multicolumn{12}{c}{\(\gamma=0.95\)} & \multicolumn{4}{c}{\(\gamma=0.95\)} & \multicolumn{4}{c}{\(\gamma=0.95\)} & \multicolumn{4}{c}{\(\gamma=0.95\)} \\ \hline \(\hat{\alpha}^{PIG-MLE}\) & 28.105 & 5.684 & 4.395 & 2.131 & 42.217 & 9.106 & 6.266 & 2.429 & 47.142 & 10.507 & 8.554 & 2.752 \\ \(\hat{\alpha}^{PIG-REE}\) & 15.747 & 3.182 & 2.341 & 1.036 & 23.076 & 5.348 & 3.593 & 1.154 & 25.580 & 6.252 & 5.118 & 1.307 \\ \hline \(\hat{\alpha}^{PIG-LE}\) & 14.869 & 3.158 & 2.349 & 1.049 & 22.415 & 5.082 & 3.438 & 1.226 & 24.810 & 5.924 & 4.741 & 1.423 \\ \(\hat{\alpha}^{PIG-ISE}\) & 14.026 & 2.838 & 2.195 & 1.065 & 21.067 & 4.545 & 3.128 & 1.214 & 23.524 & 5.244 & 4.270 & 1.375 \\ \(\hat{\alpha}^{PIG-TPE}\) & 13.800 & 2.803 & 2.186 & 1.073 & 20.672 & 4.458 & 3.088 & 1.224 & 23.169 & 5.111 & 4.190 & 1.386 \\ \(\hat{\alpha}^{PIG-KLE}\) & 13.139 & 2.473 & 1.951 & 1.015 & 19.837 & 3.996 & 2.699 & 1.160 & 22.349 & 4.593 & 3.678 & 1.274 \\ \(\hat{\alpha}^{PIG-MKLE}\) & **12.786** & **2.353** & **1.867** & **1.006** & **19.334** & **3.799** & **2.550** & **1.143** & **21.874** & **4.361** & **3.468** & **1.242** \\ \hline \multicolumn{12}{c}{\(\gamma=0.99\)} & \multicolumn{4}{c}{\(\gamma=0.99\)} & \multicolumn{4}{c}{\(\gamma=0.99\)} & \multicolumn{4}{c}{\(\gamma=0.99\)} \\ \hline \(\hat{\alpha}^{PIG-MLE}\) & 171.420 & 40.414 & 26.096 & 15.786 & 225.455 & 58.279 & 39.836 & 20.008 & 247.230 & 71.848 & 56.252 & 21.255 \\ \(\hat{\alpha}^{PIG-REE}\) & 91.340 & 24.024 & 16.571 & 10.114 & 117.311 & 33.219 & 24.659 & 11.340 & 127.790 & 42.226 & 33.631 & 13.572 \\ \(\hat{\alpha}^{PIG-LE}\) & 88.722 & 21.862 & 14.071 & 8.431 & 115.666 & 31.413 & 21.324 & 10.849 & 126.440 & 38.562 & 30.151 & 11.425 \\ \(\hat{\alpha}^{PIG-TPE}\) & 85.541 & 20.168 & 13.024 & 7.879 & 112.503 & 29.082 & 19.880 & 9.985 & 123.360 & 35.854 & 28.071 & 10.608 \\ \(\hat{\alpha}^{PIG-ISE}\) & 84.340 & 19.572 & 12.662 & 7.710 & 111.383 & 27.246 & 19.310 & 9.671 & 122.330 & 34.748 & 28.246 & 10.338 \\ \(\hat{\alpha}^{PIG-KLE}\) & 82.218 & 18.115 & 11.545 & 7.010 & 109.448 & 25.429 & 17.864 & 9.072 & 120.550 & 32.492 & 26.535 & 9.401 \\ \(\hat{\alpha}^{PIG-MKLE}\) & **80.789** & **17.299** & **10.949** & **6.661** & **108.081** & **24.335** & **17.036** & **8.704** & **119.240** & **31.090** & **25.499** & **8.912** \\ \hline \hline \end{tabular}
\end{table}
## 4 Discussion
### Evaluation of CO\({}_{2}\) Recovery with Media-Recycled Arthospira Culture  
The large CO\({}_{2}\) absorption capacity of the high-DIC medium is an advantage of the current CO\({}_{2}\) recovery process. The large capacity enables pH stability. For example, the pH of the absorbent only decreased from 10.5 to 7.9 with continued CO\({}_{2}\) supply (total absorption of 2.6 gC L\({}^{-1}\)), while it would decrease from 10.5 to 5.2 with merely 0.06 gC L\({}^{-1}\) of CO\({}_{2}\) without buffer. The pH reduction limits not only CO\({}_{2}\) absorption but also the growth of algae. Most algae have narrow ranges of suitable pHs, such as 9-10.5 for _Arthospira platensis_[17], 7-8 for _Dunaliella salima_[35], and 6-8 for _Chlorella sorokiniana_[36], and an abrupt pH change may severely hinder the growth. The pH buffer is especially important with an outdoor algae culture, since algal CO\({}_{2}\) fixation fluctuates depending on the weather and seasons. When algal CO\({}_{2}\) fixation is low, CO\({}_{2}\) supply may lead to a drastic drop in pH without buffer functions. Therefore, CO\({}_{2}\) recovery using _Arthrospira_ culture may be incorporated into the outdoor culture, which would decrease the cost and energy input in CO\({}_{2}\) recovery and algae production.  
A similar CO\({}_{2}\) recovery with media-recycled _Arthrospira_ culture was attempted by [PERSON] et al. [24]. They achieved a CO\({}_{2}\) fixation rate of 0.31 gCO\({}_{2}\) L\({}^{-1}\) d\({}^{-1}\), which was similar to 0.32-0.36 gCO\({}_{2}\) L\({}^{-1}\) d\({}^{-1}\) of this study. They revealed a correlation of growth deterioration and DOC accumulation after repeated medium recycle, which was not observed in the current experiment probably owing to the difference in the culture mode (batch or semi-continuous) and/or duration (26 days or 18 days). Another study was performed by [PERSON] et al. [22] on CO\({}_{2}\) recovery with an alkaliophilic cyanobacterium _Anabaena_ sp. They achieved nearly 100% CO\({}_{2}\) recovery and productivity of up to 0.4 g L\({}^{-1}\) d\({}^{-1}\), which were similar to the current study. They were successful in predicting kinetic reactions of CO\({}_{2}\) recovery using a model. However, neither study reported the carbon mass balance and the fate of carbon incorporated into the system. The fate of carbon may change the interpretation of recovery efficiency. For example, [PERSON] et al. [22] reported 95% efficiency of carbon utilization as to explain only about 4% escaped as CO\({}_{2}\) gas, but this efficiency does not take into account the remaining DIC and excreted DOC as unused or unnecessary carbon output. The current study revealed that 24% of assimilated carbon was released as CO\({}_{2}\) (Figure 5). If this DOC requires further treatment, such as aerobic activated sludge, the carbon footprint would be higher than previously reported algal CCU process. Thus, this study indicated the importance of carbon mass balance analysis in the practical evaluation of CO\({}_{2}\) recovery processes.
# Development and Assessment of a 4D Printing Technique for Space Applications
## 2 Materials and Methods
### Apparatus and Setup:  
The following equipment and devices were employed in our experiments:  
* Orion's A150 3D printer for 4D printing.
* A simple triangular ruler to measure the achieved programmed and recovered angles.
* A thermal imaging camera from FLIR Systems Inc. (Flir C5) to measure and validate temperatures inside the printer.
* A custom-built programming device used for hinge programming.
* High-temperature gloves for taking the programming device out of the printer.  
Our experiments involved the manipulation of several independent variables, including:  
* The temperature set for the build chamber.
* The exposure time (the duration hinges were left inside the build chamber).
* The generation of the programming device used.  
Dependent variables measured include:  
Figure 5: The process chain for the experiments: (**a**) placing the hinges (marked in red) in the programming device (both made from PEEK), (**b**) heating the hinges and the device and measuring the surface temperature, (**c**) bending/folding the hinges and letting them cool down in the vice to keep the stress applied (alternatively, in the third experiment on the influence of rapid cool down, the hinges and the device are submerged in water), (**d**) measuring the achieved fixed angle \(\alpha\), (**e**) reheating the hinges, and (**f**) measuring the achieved recovered angle \(\beta\).  
* Programmed angle \(\alpha\), used to calculate the fixity ratio (\(R_{\text{f}}\)).
* Recovered angle \(\beta\), used to calculate the recovery ratio (\(R_{\text{r}}\)).
* Recovery time (specific to Experiment 2).
* Surface temperature measured before programming using the thermal imaging camera.  
After 3D printing, the hinges were stored in a Totech Super Dry SDB-1106-40 drying rack to protect them from moisture. For programming, the hinges were securely fixated inside the programming device and subjected to heating within the build chamber.  
To minimize the influence of manufacturing batches, hinges were randomized to ensure data integrity. Replication can be easily achieved using the provided STL and CAD files for both the programming device and hinges.  
Data analysis was performed using Python, Seaborn, and Scipy. Figures were designed with consideration for readability among individuals with common color blindness conditions, and tested using the Coblis Color Blindness Simulator.
## 3 Nanosized-Lipid-Based Drug Delivery Systems in Wound Healing
### Vesicular Systems
#### 3.1.3 Ethosomes in Wound Healing
A previous study by [PERSON] et al. evaluated an ethosome-loaded Carbopol hydrogel and exposed the suitable physicochemical properties of Carbopol 974, acting as an efficient carrier system for ethosomal vesicles [130]. Skin inflammation involves complex mechanisms that can activate numerous cellular and molecular factors, and maintaining an inflammatory microenvironment, as happens in chronic wounds, can even promote carcinogenic processes. Thus, the identification of new ways of evaluation and modulation of inflammatory reactions in wound-healing phases represent important topics of interest in scientific research [131; 132; 133]. A promising therapeutic approach is the transdermal delivery of the nonsteroidal anti-inflammatory drug piroxicam, encapsulated in ethosomes and combined with iontophoresis. This formulation presented particle sizes smaller than 170 nm. Significant differences were found between the transdermal penetration of the free drug and nanoethosomal piroxicam formulation combined with iontophoresis. Furthermore, iontophoresis significantly increased ethosomal piroxicam diffusion compared with the control group [134]. Thymosin \(\beta\)-4 is a hydrophilic macromolecular protein that plays an essential role in cellular regeneration but has inadequate transdermal permeation and a reduced EE%. Therefore, researchers have provided a new design for the ethosomal gel system using thymosin \(\beta\)-4 ethosomes prepared through the ethanol infusion method. This study revealed that ethosomal gel formulation presented a better drug transdermal diffusion rate than the control group and significantly reduced the skin wound healing time [135]. Ethosomes can be a great opportunity for the noninvasive delivery of small-to-large-sized active substances [124]. In comparison with other vesicular lipid systems, ethosomes have several advantages, such as enhancing the permeability of a large group of drugs, more efficient delivery to the skin in terms of quantity and depth, a low-risk profile and administration in gel or cream formulations, which leads to better patient compliance [124].