esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Results II--Review of Research Clusters
### Cluster 4: Operation
As autonomous vessels are being actively developed, collision avoidance and warning algorithms are also being researched for application to fishing vessels. For example,Yoo et al. (2023) [52] developed a trajectory prediction model for fishing vessels using an Attention-Based Bidirectional Gated Recurrent Unit (BiGRU) to enhance short- to medium-term trajectory predictions, supporting collision avoidance for autonomous ships. The model was structured using a sequence-to-sequence (Seq2 Seq) architecture with an attention mechanism, resulting in a 7-12% improvement in prediction accuracy compared to conventional Gated recurrent unit (GRU) and Long short-term memory (LSTM) models. This model has the potential to enhance collision avoidance capabilities for autonomous ships; however, further refinement with diverse datasets is necessary to increase robustness and generalizability. Additionally, research on collision warning systems has predominantly focused on merchant ships, with ongoing development occurring. [PERSON] et al. (2021) [30] implemented a collision warning algorithm that utilized metrics, such as Distance to Closest Point of Approach (DCPA), Time to Closest Point of Approach (TCPA), and a modified Potential Assessment of Risk (PARK) model, to evaluate collision risks. The algorithm was validated through real-ship tests under various scenarios based on the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs), effectively identifying high-risk areas using millimeter-wave communication for real-time updates. While it successfully detected hazardous zones, the study highlighted that excessive alarms led to operator desensitization. Therefore, refining the algorithm to reduce false alarms and improve real-time data integration is recommended. However, further examination is necessary to determine whether such avoidance algorithms are appropriate for fishing vessels. Fishing vessels often operate at much higher speeds compared to merchant ships, and collision avoidance is frequently based on the captain's judgment rather than strict adherence to regulations. Additionally, encounters not only between merchant ships and fishing vessels but also between fishing vessels themselves can be more complex and challenging to manage. Therefore, a collision avoidance algorithm designed for fishing vessels must take these specific characteristics into account.
# Deep Learning-Based Classification of High-Resolution Satellite Images for Mangrove Mapping
## 2 Materials and Methods  
### Study Area  
Guangdong Province is one of the areas with the widest mangrove distribution and the most complete diversity of mangrove species in China. According to the latest statistics, the total area of mangroves in Guangdong is currently about 14,000 ha, accounting for about 56.9% of the total mangrove area in China. We selected the coastal area of Maoming, Zhanjiang, and Taishan cities as the study area. Figure 1 shows the locations of Maoming, Taishan, and Zhanjiang in the southwest of Guangdong Province, China. These cities have a typical subtropical and monsoon-influenced climate characterized by hot, humid, and rainy summers and mild winters [18]. The annual temperature ranges from 22.6 \({}^{\circ}\)C to 24.2 \({}^{\circ}\)C, with January being the coolest month and July to August being the warmest months. Rainfall peaks from May to September, with August receiving the most precipitation. The dry and sunny season lasts from December to January. The cities are also exposed to tropical cyclones from June to November, which can cause strong winds, heavy rains, and storm surges.
###### Abstract  
Fast steering mirrors (FSMs) are used to correct images observed by satellites. FSMs need to have large apertures and realize high precision and the positioning of the mirror in the tip-tilt and axial directions needs to be highly precise and highly responsive in order to capture large-scale, high-resolution images. An FSM with a large-diameter mirror supported by a compact magnetic suspension and driven by long-stroke voice coil motors (VCMs) is proposed in this paper. The magnetic suspension and VCM actuators enable the mirror to be highly responsive and to have long-range movement in the tip-tilt and axial directions without friction and wear. The magnetic suspension is a hybrid that has active control in the lateral directions and passive support in the tip-tilt and axial directions. An experimental FSM with an 80 mm diameter dummy mirror was fabricated and tested. The mirror's driving ranges in the tip-tilt and axial directions were \(\pm\)20 mrad and \(\pm\)500 \(\upmu\)m, respectively. Furthermore, the servo bandwidths in the tip-tilt and axial directions were more than 1 kHz and 200 Hz, respectively.  
Keywords:observation satellite; image correction; fast steering mirror; magnetic suspension; voice coil motor (VCM); wide bandwidth; gimbal mechanism +
Footnote †: journal: Electronics Electronics
# A Multi-Objective Optimization of Secure Pull Manufacturing Systems
## 2 Literature Review  
### Kanban System  
A Kanban technique pulled in numerous scientists since it was first exposed in [17]. He initially summed up the Toyota approach for deciding the suitable number of Kanbans at a workstation. It is applied, as of late, in inventory network frameworks to proficiently deal with the progression of materials. In 1987, the authors stretched out the Toyota way to deal with a fluctuating item blend issue by utilizing the following period of conjecture interest and the last period of noticed lead times [18]. After 10 years, the authors considered the over-arranging factor in the Toyota recipe for processing the quantity of Kanbans for a few creation stock control models [19]. The Kanban is a practical tool for the execution of JIT conveyance in production network tasks. In 2006, the elements of the Kanban were two-fold: they were utilized as methods for creation control and cycle improvement [20]. Kanban's underway control is tied to distinctive assembling measures to guarantee the conveyance of essential measures of material and parts at the suitable time and spot. The utilization of the Kanban, in measure improvement, is remembered for improving the activities for the creation interaction, with accentuation on decreasing stock expenses.  
Modern manufacturing processes require more accuracy, speed, and agility from the automotive industry [21]. The rapid changes in the global market have driven a significant increase in product variety, particularly in recent years. In traditional Kanban systems, complexity increases, linearly, as product variety increases [8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21]. Kanban systems are complex because of their limitations, which include controlling Lot Size information in the Kanban post, handling and transferring Kanban in order to balance production lines, losing track of inventory condition, and suffering a reduction in productivity due to the loss of Kanban cards. The problem is a lack of visibility and ability to expand to accommodate the increasing variety of products. Hence, the e-Kanban card is designed to solve the problem of traditional Kanban systems.
## 2 Grid Structure  
The grid structure, as illustrated in Figure 1, is designed using Matlab Simulink simulation platform and considers the Belgian electric network with a frequency of 50 Hz. The Flemish, Walloon, and Brussels-Capital Regions are responsible for distributing electricity with a nominal voltage of 70 kV or less [25]. In the present study, 25 kV is used for the upper grid, which is transformed to 11 kV. In addition, a second transformer is used to set the voltage for the distribution network to 400 V.  
The three-phase grid structure is composed of a low voltage loop, which is 400 V, a centralized PV farm, a centralized stationary ESS, and augmented with domestic loads that encompass 692 houses. The ESS is equipped with an FLC to control the charging and discharging rates and enable B2G and G2B functionalities.
## 5 Simulation Results
### Simulation Results
#### 5.2.3 Packet Delivery Ratio  
PDR is calculated as the percentage of packets successfully transmitted to packets generated.  
\[PDR=\frac{\text{Number of received packet}}{\text{Number of generated packet}} \tag{8}\]  
PDR over link asymmetry is illustrated in Figure 12. The proposed protocol improves the packet delivery ratio by approximately 10% considering asymmetric percentage from 10% to 90%. The PDR of COASYM-MAC is higher than ASYM-MAC because, in ASYM-MAC, the sender cannot send data to the receiver; it waits \(t\) time and then sends the long preamble in the case of link asymmetry. In that duration, the new packets are generated to the sender; this increases the generated packets rather than transmitted packets and decreases the PDR. On the other hand, in COASYM-MAC, if the sender cannot transmit data to the receiver, it waits \(t\) time and sends data using cooperative nodes. If the sender cannot get the beacon from its siblings, it waits another \(t\) time for a neighbor's beacon. If it gets the beacon from a neighbor, it immediately makes this neighbor a parent and solves link asymmetry permanently. As a result, PDR is increased in COASYM-MAC over ASYM-MAC. The percentage of gain in packet delivery ratio for COASYM-MAC is 74.2%, 71.4%, and 70.47% for 27 nodes (Figure 12a), 54 nodes (Figure 12b), and 90 nodes (Figure 12c), respectively, as compared to the ASYM-MAC protocol when link asymmetry is 90%.
# Online Sparse DOA Estimation Based on Sub-Aperture Recursive LASSO for TDM-MIMO Radar
## 4 Discussion  
### Results Analysis  
In this paper, a LASSO-based sparse DOA estimation method for online processing of TDM-MIMO radar sub-aperture data is proposed. In this paper, a detailed comparison of the computational complexity, simulation results, measured data of point targets, and measured data of surface targets by various methods was carried out.  
The results obtained in this paper show that the proposed online DOA method works well under both simulated and experimental conditions. It should be noted that the computational complexity of the IAA method in Table 1 does not consider the number of iterations, and its total computational complexity should be expressed as \(O\big{(}Q(M_{t}M_{t})^{3}\big{)}\), where \(Q\) represents the number of iterations of IAA. Referring to the article [21], the iteration number of the IAA method is set to 15 in all simulations and measurements in this paper.  
Since the proposed method can output DOA results from sub-aperture data in real time, we only give the complexity of each sub-aperture recursion in Table 1. The total calculation times of multiplication and division is expressed as \((Q+1)M_{t}K^{2}+\big{(}9Q+{M_{r}}^{2}+{M_{r}}\big{)}M_{t}K\), and the computational complexity is \(O\big{(}(Q+1)M_{t}K^{2}\big{)}\), where \(Q\) represents the number of iterations of the proposed method. \(M_{t}\) represents the number of transmitting array elements, namely, the number of recursions required for full aperture. \(M_{r}\) represents the number of receiving array elements, namely, the sub-aperture length. In addition, according to the configuration of the transmitting and receiving array elements, \(M_{t}\) and \(M_{r}\) can also interchange roles.  
Comparing (c) and (d) of Figures 4, 8 and 10, it is obvious that the proposed method can maintain the recovery performance of the traditional LASSO method while performing low-complexity online DOA estimation. It should be mentioned that the selection of parameter \(\lambda\) in Equation (7) refers to the article [28]. In the proposed method, \(\lambda=\sqrt{m_{t}M_{r}\text{log}_{2}K}\), where \(m_{t}=1,2,\ldots,M_{t}\) is the current recursive sub-aperture ordinal.  
In the follow-up research, on the one hand, under the conditions of the moving platform and moving target, Doppler phase and model error compensation need to be considered to further improve the DOA accuracy of the proposed method. On the other hand, after the motion compensation, the relevant hardware platform should be built to implement the TDM-MIMO data's real-time processing on FPGA or DSP using the proposed method.
## 2 Related Works
[PERSON] discovered that compared with other centrality indicators (reciprocal closeness, complement-derived closeness, eigenvector centrality, etc. ), degree and betweenness could be used more satisfactorily to select important nodes [39]. Therefore, in this study, two heuristic node deliberate attack strategies are designed using degree and betweenness. In addition, the failure of nodes under network attack belongs to a transition process in practice, and the nodes do not die immediately. Accordingly, the arbitrary removal of these nodes does not conform to the actual circumstances. In this paper, we presume that the energy of nodes will decline significantly once attacked. For balancing invulnerability and energy consumption in WSNs, game theory has become a unique method for developing routing protocols, and its rational behavior can be applied to the systematic analysis of hierarchical networks [40]. The routing protocols based on game theory have demonstrated more attractive advantages than other protocols regarding network lifetime, energy efficiency, and route establishment time [41]. Considering the factors such as residual energy and link quality, the loss function and profit function can supply proper decisions in CH competition, simplifying the optimal CH selection process for cluster-based routing protocols [42]. [PERSON] et al. utilized an innovative routing protocol named game-theory-based energy efficient clustering routing protocol (GEEC) to reduce average energy consumption [43]. [PERSON] et al. employ an efficient energy-aware and game-theory-based clustering protocol (EEGC) to select CHs through equilibrium probability of the game and residual energy dependence index [44]. [PERSON] et al. used a hybrid, game-theory-based distributed clustering protocol (HGTD) for getting an equilibrium probability by playing a localized clustering game for each node [45]. The advantages and disadvantages of the above-mentioned three routing protocols are summarized in Table 1. However, these studies on routing protocols based on game theory rarely integrate QoS indexes into the game process and generally explore network performance through mixed routing indicators. Therefore, QoS cannot be ensured under external attacks because network invulnerability is not involved in the definition of the game model. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Protocol** & **Advantage** & **Limitation** \\ \hline GEEC & Reduced energy dissipation, & \\  & location awareness & Generation of clusters with a single node \\ EEGC & Energy-related payoff definitions & Residual energy obviated from threshold function calculation, \\  & unoptimized transmission path after clustering \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Conventional routing protocols based on game theory in terms of technical strengths and weaknesses.
# Adaptive Multi-Channel Clustering in IEEE 802.11s Wireless Mesh Networks +
## 6 Experimental Validation
### Assessment of Online Cluster Adaptation
#### 6.3.2 Addition and Relocation of Nodes
Although nodes usually detect link breaks after one beacon frame period (default value 1 s), the update of the path entry to the CH, whose next-hop information may have become obsolete, does not occur until the next PREQ frame is received. Since PREQs are always sent as unacknowledged broadcasts, they have a lower delivery probability compared to unicast frames. The loss of a PREQ frame thus delays the path update by another 5 s.  
After link switching on the additional node, it must detect the path update not only at the link layer but also in the CHaChA application before it can send the current NH2 CH information to the control PC. In our prototype, the 802.11s information of the Linux kernel is sampled every 2 s. Depending on the offset of the PREQ interval (5 s) and sampling cycle, a path change is thus detected after 6-8 s in the node's application and visualized after another 2 s according to the transmission interval of the NH2 CH messages. In addition, there are delays due to undelivered PREQ messages. In the experiment discussed here, link changes appeared in the visualization after 12-20 s.  
Second 75 in Figure 21 shows the detected link switch from node 2 to node 3, which had been triggered in second 60. By crossing the cluster boundary, the isolation detection of the new node detected the link loss to the CH of the purple cluster, initiating a change to the green cluster. Since only one WLAN adapter (primary interface) was used in all experiments and all nodes were connected on the base channel, the path to the purple CH could still be established through the CM of another cluster. Thus, isolation detection was not possible based on information from the secondary interface that would signal a lost path to the CH on the cluster channel. Deviating from the concept in Section 4.4.2, detection was instead performed by checking whether the path to the current CH passes through a CM of the same cluster. The members of all clusters are announced in the CH broadcasts in the network and were thus also known to the new node. Successful joining of the green cluster became apparent in second 79, after fresh CH messages of all clusters had been sent to the control PC. The now reduced number of nodes in the purple cluster subsequently caused the roaming of an edge node from the red cluster, resulting in re-balancing of the constellation. As shown in Figure 21, the link switches to nodes 4 and 5 appeared in the visualization after 19 and 12 s, respectively. In summary, the concepts for subsequent network joining as well as isolation detection and cluster balancing were successfully tested in combination. While the focus of these experiments was on functional validation, the choice of shorter update intervals (CHaChA and 802.11s parameters) can increase responsiveness to network changes. Depending on the use case, a compromise must be found between latency and messaging overhead.
# Toward Sustainability of the Aqueous Phase Reforming of Wastewater: Heat Recovery and Integration
## 2 Materials and Methods
* Reactor thermal operation mode: the reactions involved in the APR process were considered to take place in an isothermal and isobaric regime, generating the gas-product stream and treated wastewater. * Gas drying: water from the gas-product stream leaving the reactor was removed by condensation at high pressure in order to maximize heat recovery (global heat transfer coefficient, U, increases with temperature), as has also been proposed in previous studies [2,13]. * Heat recovery from treated wastewater: treated wastewater left the reactor at reaction temperature, and heat was recovered from this stream by exchange. * Combustion of gas-product stream and heat recovery: the gas-product stream containing H\({}_{2}\), CH\({}_{4}\) and CO\({}_{2}\) was considered a fuel gas that was burned in a fired heater for heat recovery. The ability of the process to cover heat intake was assessed through the parameter of heat covering (HC), which has been defined for the purpose of this work as follows:  
\[\text{HC}\left(\%\right)=100\cdot\left(\Sigma\text{Qi}/\Sigma\text{Qc}\right) \tag{3}\]  
where Qi is the heat flow in the steps in Figure 1 where heat is recovered, and Qc is the heat flow in the steps where heat is consumed. For the heat-flow expression, a conventional criterion has been used, i.e., Q < 0 for recovery and Q > 0 for consumption. Thus, the HC parameter took positive values when the process showed a net heat deficit and took negative values when the total heat generated was higher than the total heat consumption. The most significant heat consumptions in the process were:  
* Pressurized inlet wastewater preheating to reach the reactor operating temperature: in the industrial process, it is usual to cover it (at least partially) with heat interchange with the reactor outlet stream. * Reactor heat demand (reactor duty): the most important heat consumption. The significance of this contribution did not come from the reaction enthalpy (which is not high) but from water evaporation, which is a key aspect for cost-efficient operation when processing diluted feeds [23]. On the other hand, heat could be recovered from:  
* Treated reactor effluent: can be used for reactor-feed-stream preheating as indicated above. * Condensation of water present in gas stream from the reactor; it was highly dependent on the amount of water evaporated in the reactor. * Gas stream from the APR reactor: by combustion of this stream, a large amount of heat could be recovered both in the furnace unit and from hot exhaust gases.
## 3 Experimental Section
### Phenology Timing and Time Series  
Remotely sensed surface reflectance indices, such as EVI, are commonly used to characterize vegetation properties based on surface greenness and have been widely used to monitor tree phenology and photosynthetic activity [70,71]. Spring and autumn vegetation phenology at each tower site was estimated using a new algorithm that exploits a time series of data from the 30 m resolution Landsat Thematic Mapper satellite sensor [72]. Only landsat pixels with average \"summertime\" EVI above 0.6 were included in this analysis so that the effect of building shading and drought prone urban lawns--both of which tend to push EVI below 0.6--could be mitigated. While this method reduces biomass estimates in shaded areas, shaded vegetation comprises a very small percentage of total vegetation. We validated this method in Boston using Bing Maps bird's eye pictometry.  
The spring and autumn phenological dates roughly correspond to the timing when leaf lengths reach 25% of their seasonal maximum (\"green-up\") and 90% coloration (\"brown-down\"), respectively. Annual phenology dates at each pixel were estimated based on the deviation in Landsat observations in 2011 relative to the 1982-2001 long term average phenology at each pixel. Pixels with low seasonal amplitude in EVI were classified as non-forest and removed from the analysis. We then calculated the median of all retrieved phenology dates across a roughly 3 km \(\times\) 3 km window (100 \(\times\) 100 pixels) centered on each study site. The seasonal EVI trend was computed using LOESS with a span of 0.5.  
Since Boston, Worcester and Harvard Forest are 5, 70, and 99 km away from the coastline, respectively, the Atlantic Ocean likely moderated climate and influenced phenology along our urban to rural gradient. However, given the results of [PERSON] _et al._ (2004) which highlight clear urban heat islands in cities within 75 km of the coast, we feel that we are seeing a primarily urban signal [73].