esa-sceva/satcom-chunk-collection huggingface dataset:
# Semi-Active Vibration Control Based on a Smart Exciter with an Optimized Electrical Shunt Circuit
## 3 Numerical Analysis of Vibration Reduction Potential
### Numerical Evaluation of Vibration Reduction Potential
#### 3.2.2 Analysis of Narrowband Effect Due to Harmonic Excitation  
The narrowband vibration reduction effect has been investigated using the sine wave block as the input for the Simulink model. The angular frequency under the block parameter is \(2.\pi\):\(143\) rad/s, which corresponds to the first natural frequency of the panel  
Figure 7: Displacement magnitude vs. frequency of panel: (**a**) without the SE and (**b**) with the SE.  
without the SE. Therefore, the dominating mode shape is the first bending mode. The results obtained from this analysis are shown below. Figure 8 shows the displacement of the three positions over time. Figure 8a is for the panel without the SE and Figure 8b for the panel with the SE. The blue curves represent the displacement of position P2, which has the greatest amplitude. The black curves are for position P1, which has the smallest amplitude. The red curves are for position P3, whose amplitude is between the amplitudes of positions P1 and P2. After reviewing Figure 8a,b, we can observe that vibrations can be effectively reduced by the SE.  
The maximum amplitude of the panel without the SE is reduced from \(4.5\times 10^{-3}\) m down to \(0.6\times 10^{-4}\) m. Hence, the vibration level has been reduced by 37.5 dB. A reduction of 32.4 dB would be found if the steady state is compared at t = 9 s.  
In order to study more details of the harmonic oscillation and the influence of SE, the steady-state vibration between t = 9.95 s and t = 10 s has been analyzed. Figure 9 shows the waveform of the panel at P1, P2 and P3. Figure 9a is for the panel without the SE and Figure 9b is for the panel with the SE and the RL-shunt. The wave amplitudes correspond to the amplitude in Figure 8. In addition, the blue, black and red curves show no phase shift at P1, P2 and P3. After comparison of these figures, we can see that the SE does not change the waveform. In summary, the results of the simulation demonstrate the great vibration reduction potential of a SE with an RL-shunt.  
Figure 8: Displacement over time of the panel (**a**) without the SE and (**b**) with the SE.
## 4 Experiments
### Experiments on the Performance of Descriptors
#### 4.2.2 Evaluation Metrics of Performance of Descriptors  
Our proposed multi-scale covariance matrix descriptor includes only one parameter: random variables in the vector \(\varphi\). As a result, the descriptor's performance against various variables in the vector \(\varphi\) must be evaluated. In the meantime, a performance comparison of our proposed feature descriptor with state-of-the-art feature descriptors is required.  
Our experimental findings are shown using the recall versus 1-precision curve (RP curve). The recall versus 1-precision curve is a frequent statistic in the literature for evaluating a descriptor [36]. It is created in the following manner. Given a target point cloud, a source point cloud, and a ground truth matrix, keypoints from the target and source point clouds are detected and described as target feature descriptors and source feature descriptors, respectively, using our proposed multi-scale covariance matrix descriptor algorithm. The total number of positives is used to calculate the number of target feature descriptors. To determine the closest feature descriptor, a target feature descriptor is compared to all source feature descriptors. If the distance between the target feature descriptor and the nearest source feature descriptor is less than a certain threshold, the pair is considered matched. Furthermore, a matched feature pair is regarded as a valid positive if the distance between their physical places is short enough; otherwise, it is considered a false positive. The RP can be calculated using these numbers.  
\[recall=\frac{the\ number\ of\ correct\ positives}{total\ number\ of\ positives} \tag{32}\]  
\[1-precision=\frac{the\ number\ of\ false\ positives}{total\ number\ of\ matched\ feature\ pairs} \tag{33}\]
## 4 Proposed System
### Segmentation
#### 4.1.3 Watershed Algorithm  
Thirdly, we applied the watershed algorithm following the process of Sections 4.1.1 and 4.1.2, on the markers, the \"seeds\" of the future image regions. The watershed algorithm is another region-based algorithm taken from mathematical morphology which marked around the hand gesture of the image [56]. Finally, a bitwise mask is employed be-tween the watershed generated mask image and the input images to produce a segmented image.
## 2 Mobility Models in FANETs
### Path Planned Mobility Models
#### 2.4.2 Semi Random Circular Movement  
The Semi Random Circular Movement (SRCM) model is intended for UAVs that need to move along curved paths. It may be used to simulate UAVs flying around a specific central point to collect data [69]. After completing a full round, the UAV chooses a new circle at random and goes around the same predetermined center once more. Figure 17 depicts the movement of UAVs using SRCM. Further, the key benefit of SRCM is that it reduces the possibility of UAV collisions owing to the circular pattern of the motion. SRCM is widely adopted in search and rescue missions and has been implemented in a variety of applications such [70; 71].
## 4 Analysis and Evaluation of the PPP-B2b and Broadcast Ephemeris Performance
### Evaluation of the PPP-B2b and Broadcast Orbit Accuracy
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Ephemeris Type**} & \multicolumn{3}{c}{**MEO Orbit (RMS/m)**} & \multicolumn{3}{c}{**IGSO Orbit (RMS/m)**} \\ \cline{2-7}  & **Radial** & **Along** & **Cross** & **Radial** & **Along** & **Cross** \\ \hline BDS broadcast ephemeris & 0.11 & 0.31 & 0.28 & 0.17 & 0.34 & 0.47 \\ BDS PPP-B2b & 0.10 & 0.27 & 0.24 & 0.15 & 0.32 & 0.41 \\ GPS broadcast ephemeris & 0.17 & 0.92 & 0.49 & - & - & - \\ GPS PPP-B2b & 0.12 & 0.34 & 0.26 & - & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Statistical accuracy of GPS and BDS-3 satellite orbits. Figure 5: Orbit error series of BDS-3 IGSO PPP-B2b (**left**) and the BDS-3 IGSO broadcast ephemeris (**right**).
# A Review of Literature on Vehicle Routing Problems of Last-Mile Delivery in Urban Areas
## 5 Implications and Future Research
### Opportunities for Future Research  
The literature survey suggests the need for the following future research in last-mile delivery studies.  
1. Last-mile delivery deals with the B2C (business to customer) model of business, which involves a high level of dynamism: frequent updates of the problem environment, including customers' real-time order changes. The urban condition of delivery and the use of automated systems make the problem highly stochastic. Considerations of the dynamic and stochastic nature of the problem environments are needed for more robust logistics planning.
2. Not only autonomous aerial drones and unmanned trucks, but other possible autonomous devices have distinct characteristics of service: speed, size, geographical barriers, and coverage spans. The reliability of the units and local intelligence to cope with unexpected circumstances along with the improvement in the technical characteristics are challenging. The development and creative use of delivery modes will significantly enhance logistics efficiency, especially for urban logistics.
3. Most studies use simulated data. Rigorous integration of academic models and transactional data will improve the validity of the LMD models. Data gathering becomes more challenging, especially to reflect the diverse characteristics of different areas and people.
4. Comprehensive assessments of the environmental impact of various LMD approaches in all four categories of LMD configurations are needed to understand their sustainability implications. People understand that vehicles are responsible for a large portion of pollution. Different delivery approaches may help or harm the environment. Holistic considerations of pollutants generated by both customers and delivery systems as well as pollution from energy production and the consumption life cycle are warranted.
* Individuals are willing to help both the supply and demand sides of city logistics by serving as ODs (occasional driers) and providing optional delivery points. The development of various business models utilizing individuals and careful operational planning will improve both customer satisfaction and firms' profitability.
* The routing problem in LMD is computationally difficult. Innovative ways of using big data analytics, AI-based procedures, heuristic/metaheuristic approaches, and exact solution approaches along with their hybrid methods are warranted.  
Conceptualization, J.J., E.A., R.J. and K.A.; methodology, R.J.; software, Not Applicable; validation, R.J., J.J. and K.A.; formal analysis, E.A.; investigation, R.J. and E.A.; resources, E.A.; data curation, E.A.; writing--original draft preparation, R.J. and E.A.; writing--review and editing, J.J. and K.A.; visualization, R.J. and E.A.; supervision, J.J.; project administration, J.J.; funding acquisition, Not Applicable. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The authors declare no conflict of interest.
# Electrocatalytic Nanomaterials Improve Microbial Extracellular Electron Transfer: A Review
###### Abstract  
Microbial electrochemical systems that integrate the advantages of inorganic electrocatalysis and microbial catalysis are expected to provide sustainable solutions to the increasing energy shortages, resource depletion, and climate degradation. However, sluggish extracellular electron transfer (EET) at the interface between electroactive microorganisms and inorganic electrode materials is a critical bottleneck that limits the performance of systems. Electrocatalytic nanomaterials are highly competitive in overcoming this obstacle due to their effective association with microbial catalysis. Therefore, this review focuses on the cutting-edge applications and enhancement mechanisms of nanomaterials with electrocatalytic activity in promoting microbial EET. First, the EET mechanism of microbial electrocatalysis in both microbial anodes and cathodes is briefly introduced, and then recent applications of various electrocatalytic nanomaterials in diverse microbial electrochemical systems are summarized, including heteroatom-doped carbons and precious metal, as well as transition metal oxides, sulfides, carbides, and nitrides. The synergistic effects of nanomaterial electrocatalysis and microbial catalysis on enhancing interfacial EET are analyzed. Finally, the challenges and perspectives of realizing high-performance microbial electrochemical systems are also discussed in order to offer some reference for further research.  
microbial electrochemical system; electrocatalysis; extracellular electron transfer; nanomaterial; electrode; electroactive microorganism +
Footnote †: journal: Applied
## 2 Materials and Methods
### Image Quantification, Data Analysis, and Statistical Testing  
Images from all culture conditions and time points were analyzed and scored for gap distance and number of cells in the gap using Nikon Elements Basic Research software (4.10.01) and Fiji. Briefly, a grid overlay was used to choose 10 consistent points across the culture in each image to measure the distance between the two edges of the scratch region at the specified point beginning immediately following the scratch assay to obtain the original gap distance. This was accomplished using the phase-contrast images, initially captured in Nikon Elements Basic Research, with the grid overlay implemented in Fiji. The distance of cell migration or process outgrowth (astrocyte cultures) or neurite outgrowth (neuron cultures) was thus measured as the furthest extending cell or neurite across the middle of the gap at each of the 10 grid points by researchers blinded to the experimental group. The percentage of the gap distance remaining was calculated based on the original width of the gap for each treatment and at each time point post-injury. To determine statistical significance, GraphPad Prism 7 was used to perform two-way analysis of variance (ANOVA) on astrocyte-only data, as two variables (time and intensity of plasma stimulation were compared); whereas one-way ANOVA was conducted on neuron-only cultures and co-cultures (only the effect of plasma stimulation was compared). Where significant differences existed between groups, [PERSON]'s multiple comparisons posthoc test was used in all cases (\(p<0.05\) required for all statistical tests). Data are represented as the mean percentage of gap closure \(\pm\) standard error of the mean (SEM).
## 2 Materials and Methods
### X-ray Visibility  
To improve radiographic appearance, an X-ray-visible spine was designed, manufactured, and bolted under the base centerpiece. The design was based on anonymized patient CT data. Thoracic vertebrae T4-T9 and their intervertebral disks were segmented and turned into stereolithography (STL) files for VP 3D printing (Figure 2A). Anycubic Basic Clear resin was doped with CaCO\({}_{3}\) and BaSO\({}_{4}\) to make the material more radiopaque. The mass attenuation coefficient (MAC) of Anycubic Basic Clear Resin was estimated using the material data sheet [17] and MAC of chemical elements at 80 keV [18]. Similarly, the ideal MACs of BaSO\({}_{4}\) and CaCO\({}_{3}\) were calculated based on their chemical compositions. To simulate the radiopacity of different tissues during fluoroscopy, the MACs of cortical bone and soft tissue at 80 keV were matched. Subsequently, 20.178 g of BaSO\({}_{4}\) was added to 1 kg of resin to simulate cortical bone, while 56.340 g of CaCO\({}_{3}\) was added to 1 kg of resin to simulate soft tissue. The literature reports that the average thoracic vertebra is made of 82.87% soft tissue and 17.13% cortical bone by mass [19]; consequently, soft tissue and cortical bone resins were mixed in that ratio to simulate vertebral bone. Thoracic vertebrae T4 to T9 were VP 3D printed using vertebral bone resin (Figure 2B). Soft tissue resin was used to VP 3D print the intervertebral disks.  
The experimental simulator was scanned using the Artis Q Biplane C-Arm (Siemens, Munich, Germany) in cone beam CT mode, and 540 voxels were analyzed for each resin vertebra and each disk, to be compared against values in the literature (Figure 2D,E). The simulator was imaged using fluoroscopy with the Artis Q C-Arm. Five samples of 400 pixels were analyzed from the vertebrae and five samples of 400 pixels were analyzed from the background. The same procedure was repeated for anonymized patient data (Figure 2C). Percentage contrast was calculated and compared.
## 4 Hybrid Message Passing Detector
The ISI \(x[c]\) can be detected by applying the a posteriori rule, i.e.,  
\[\hat{x}[c]=\arg\max_{x[c]\in\mathcal{A}}b(x[c]). \tag{38}\]  
From Equation (37), it is evident that there are \(Q\) states in the detection procedure of each data symbol, and the summation needs to encompass all symbols within \(\mathbf{x}_{d}\) except \(x[c]\). Consequently, the summation operations requires \(|\mathcal{Q}|^{P}\) operations. Considering that the operational term is insignificantly small in comparison to the exponentially growing term \(|\mathcal{Q}|^{P}\), the complexity is effectively \(\mathcal{O}\big{(}|\mathcal{Q}|^{P}\big{)}\). It is worth noting that the computation complexity would be an overwhelming \(\mathcal{O}\big{(}|\mathcal{Q}|^{P(2\mathbf{N}_{T_{i}}+1)}\big{)}\) without the Gaussian approximation, rendering it nearly impossible for implementation. Hybrid detection schemes may involve more complex algorithms and processing steps compared to simpler, single-method detection schemes. Integrating multiple detection methods introduces challenges in terms of system implementation. The coordination and synchronization of different algorithms, especially in real-time applications, can contribute to increased an design and implementation complexity. The primary motivation for adopting a hybrid detection scheme is often to enhance robustness. By combining multiple methods, the system becomes more adaptable to diverse operating conditions, variations in the signal environment, and potential challenges like noise, interference, or fading. Hybrid schemes can lead to an improved detection accuracy compared to individual methods. Each detection method may excel in specific scenarios or under certain conditions, and their combination can provide a more comprehensive and reliable detection capability.
## 3 Results and Discussion  
### Open Circuit Potentials  
The value of open circuit potentials could represent the potentials of steel bars out of the circuit state as well as reflect the degree of formation or the corrosiveness of the passivation film. A passive film was perfectly formed and performed a higher resistance, while the OCP was about \(-0.35\) V, so that steel bars could be protected and the corrosion probability could lower [35]. Once the open circuit potential became more positive, the steel bar approached corrosion, indicating the incomplete passive film developed on the steel bar. The OCP values of the samples with different kinds of corrosion inhibitors, together with the samples soaked in the simulated pore solutions without corrosion inhibitors, are listed in Table 2.  
Compared with original steel bars, OCP values of steel bars without any corrosion inhibitor become positive after soaking in the chloride-containing solution for 5 days (5 d). After 30 and 60 days, the OCP value becomes more positive. Especially after 60 days soaking, the potential has already exceeded the index of 0 V and reached 0.12 V, indicating the occurrence of corrosion on the steel bar surface. As for the calcium nitrite, the OCP value decreased slightly at 5 d and then rose again after 60 days of calcium nitrite protection. In the early stage (5 d), little calcium nitrite was absorbed on steel bar surface, leading to the shortage of the protecting effect on the passive film, while the protecting effect enhanced with the precipitate process of calcium nitrite in the late stage (60 d) of chloride erosion. The OCP of the multi-component corrosion inhibitor enhanced quickly and remained at a high level, reaching \(-0.37\) V and \(-0.38\) V at 5 days and 60 days, respectively. This phenomenon demonstrates the excellent corrosion resistance of multi-component corrosion inhibitor compared with any other groups. Regarding the organic and inorganic corrosion inhibitors, the OCP of all the samples changes to a more negative direction over time in different degrees. Molybdates could reduce the current density sufficiently and change the OCP to more negative values [36]. The OCP value of the organic corrosion inhibitor sample is slightly lower compared with that of the inorganic corrosion inhibitor, which may relate to the different corrosion resistance mechanisms of corrosion inhibitors.
# Object-Level Semantic Map Construction for Dynamic Scenes
## 3 Methodology  
### System Overview  
Our proposed method, built on the ElasticFusion [5] framework, enables real-time dense multi-model dynamic RGBD SLAM at the object level. In addition to obtaining camera poses accurately, our system can detect, track, and reconstruct multiple objects, including dynamic and static objects, while precisely segmenting each object instance and assigning it a corresponding semantic label. Figure 1 illustrates the proposed method in a detailed flowchart, which involves four steps.  
Figure 1: Overview of the system pipeline. Images data captured by an RGB-D camera serve as the input data for the motion detection, segmentation, camera pose tracking, and map construction modules, among others. Then, the precise camera pose and object-level semantic map can be obtained.  
1. Firstly, object motion detection is performed by 3D object tracking based on a priori knowledge of the object model database updated by the previous frame to find the moving object in the object database.
2. Secondly, object instance accuracy segmentation is achieved using a combination of semantic and geometric cues in the current frame, then associated with the object database to find the dynamic part of the current image data.
3. Thirdly, the camera pose is obtained precisely through dynamic part elimination in the current frame and each object model pose in the database is updated using the accurate camera pose.
4. Fourthly, the object model is updated and fused with each frame input, and the 3D object-level semantic map is reconstructed incrementally.  
The details of each component of the pipeline will be described below.
## 3 Test Results
### Shear Force--Slip Relationship  
Figure 5 shows the shear force--slip relationship. To quantify the effects of test parameters, the maximum strength, initial stiffness, and slip capacity were evaluated from the test results. The maximum strength (\(V_{m}\)) was taken as the peak load. The initial stiffness (\(K_{i}\)) was taken as the secant stiffness at the point where steel anchors reached the yield strain, and the yielding of steel anchors was determined by the measurement as shown in Figure 6. The slip capacity (\(\mu\)) was taken as the ratio of yield slip-to-ultimate slip (\(\delta_{y}/\delta_{u}\)), in which the yield slip \(\delta_{y}\) was defined as the slip measured at the yielding of steel anchors and the ultimate slip was defined as the slip corresponding to \(0.8V_{m}\) after the peak load [24]. The performance points of \(\delta_{y}\), \(V_{m}\), and \(\delta_{u}\) are marked with a circle, triangle, and cross on each plot of Figure 5, respectively, and the test results are summarized in Table 3.  
To clarify the effect of each test parameter, the shear force--slip behavior was compared in terms of steel anchors in Figure 7a, and in terms of steel beams in Figure 7b.  
The figure reconfirms the higher effect of steel anchors than steel beams on structural behavior: similar behavior in Figure 7a for same steel anchors with different steel beams; but large difference in behavior in Figure 7b for same steel beams with different steel anchors. In general, the geometry of steel beams and the depth of the concrete-filled U-shaped flange (UO75 and UO100) had no significant effect. A similar observation can be found in a previous study [18]: for most shear connectors in push-out tests, the effect of the thickness of the connected plate could be ignored. On the other hand, the type of steel anchors had a distinct effect. The specimens with C-channel anchors showed highest load-carrying capacity, but the load reduction after the peak load was most drastic. The specimens with Z-channel anchors showed a similar behavior to those with C-channel  
Figure 5: Shear Force—Slip Relationship: (**a**) H-S; (**b**) UI-S; (**c**) UO75-S; (**d**) UO100-S; (**e**) H-Z130; (**f**) H-Z230; (**g**) UI-Z130; (**h**) UO75-Z230; (**i**) UO100-Z230; (**j**) H-C130; (**k**) H-C230; (**l**) UI-C130; (**m**) UO100-C230; (**n**) Definitions of Performance Points.  
Figure 6: Shear Force—Strain Relationship of Steel Anchors: (**a**) S-group; (**b**) Z-group; (**c**) C-group.  
anchors, but the load reduction occurred in a slightly slower rate. As the length of channel anchors increased (Z130 and Z230 or C130 and C230 with the same welded length), the load-carrying capacity was increased. Although there was also a sudden drop after reaching the peak load even in the case of using stud anchors, the specimens with stud anchors reached the peak load in a slow rate and showed most ductile behavior.