esa-sceva/satcom-chunk-collection huggingface dataset:
###### Abstract  
In this study, a spatial model has been developed to investigate the role of water temperature to the distribution of bacteria over the selected regions in the Bay of Bengal, located in the southern region of Bangladesh using next-generation sequencing. Bacterial concentration, quantitative polymerase chain reactions, and sequencing were performed on water samples and identified Acidobacteria, Actinobacteria, Bacteroidetes, Chlorobi, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, Proteobacteria, and Verrucomicrobia. The spatial model tessellated the parts of the Bay of Bengal with hexagons and analyzed the relationship between the distribution of bacteria and water temperature. A geographically weighted regression was used to observe whether water temperature contributed strongly or weakly to the distribution of bacteria. The residuals were examined to assess the model's fitness. The spatial model has the potential to predict the bacterial diversity in the selected regions of Bangladesh.  
spatial modelling; bacterial distribution; next generation sequencing; water temperature; Bangladesh 2020 10 2537 10.3390/app10072537
# Numerical Investigation of Tonal Trailing-Edge Noise Radiated by Low Reynolds Number Airfoils
## 4 Results of the Parametric AFL Sensitivity Study
### Variation in Reynolds Number at \(\alpha=2^{\circ}\): Tone-Producing Regimes  
To advance the understanding of the effect of flow velocity on tonal noise production, additional simulations were conducted for a range of \(Re_{c}\) at a fixed AoA of \(2^{\circ}\). Clearly, all investigated cases are within the tone-producing region, and the cases of \(Re_{c}\) = 144,000 (20 m/s) and \(Re_{c}\) = 288,000 (40 m/s) selected for illustration exhibit well-defined tonal spectra in the near-field at 2 chords directly above the TE (Figure 19). BL statistical analysis reveals a direct correlation between increasing \(Re_{c}\) and the decreasing chordwise extent of the suction side LSB (Figure 20 and Table 5), while the LSB on the pressure surface retains nearly the same size at the TE (with \(C_{f}\) becoming more negative towards the TE with increasing velocity).  
Correspondingly, the LST results demonstrate that an increase in \(Re_{c}\) leads to a surge in amplification of the peak instability mode on the airfoil pressure side (Figure 21). At the same time, as the suction-side LSB shrinks while the instability saturation location shifts further upstream from the TE, the contribution of the suction surface to the radiated sound diminishes relative to that from the pressure side. It is expected that a further increase in flow velocity will result in the eventual suppression of the separation region from the suction side. When this occurs, the pressure-side LSB will provide the sole contributor to the radiated total noise. These trends are in agreement with the experimental findings of [PERSON] et al. (2018), [PERSON] et al. (2019), and [PERSON] et al. (2020), where tripping the BL on either side of the airfoil revealed a dominant tonal noise contribution from the suction side at the lower flow velocities, and from the pressure side at the higher flow velocities.  
Further extension of the flow regime towards a lower \(Re_{c}\) (<144,000) would lead to the formation of a fully laminar BL and result in the absence of the LSB. Consequently, without the LSB, the switch from T-S to K-H waves would not be possible and thus the rapidly amplifying instability modes needed for the self-sustained acoustic feedback can never be established. While it is possible for the shedding tone to still exist, it would likely be much lower in amplitude due to the lack of reinforcement from the feedback loop ([PERSON] et al., 2018). On the other hand, increasing the \(Re_{c}\) (>288,000) would suggest transitioning to the fully turbulent BL flow, with both the acoustic feedback and the shedding tone fully suppressed.
## 3 Methodology
### Data Sources  
#### 3.1.1 Mobility Data  
Speed data from INRIX.com was employed in the study. INRIX.com uses GPS enabled probe vehicles to collect this information. The geocoding is based on Traffic Message Channel (TMC) codes, as defined by Tele Atals and Navteq. Each TMC corresponds to a directional roadway segment with geolocated begin and end points. INRIX reports average travel times, average speeds, reference speeds, and scores by time of day and day of the week. The score indicates if the reported speed is based on historical data, real time data, or a blend of the two.  
In the study area, the Regional Integrated Transportation Information System (RITIS) provides an integrated spatiotemporal contour map of the traffic congestion for each TMC segment by time of day (RITIS) [33]. RITIS also provides contour maps for comparative speeds, congestion, a travel time index, and so forth. This study used 15 min. aggregated congestion data. RITIS defines the congestion value, _C(i,t,m)_, for segment (_i_) at time (_t_). \(i\) is TMC a segment and \(t\) is specified time interval in a day (e.g., 8:00-8:15, 15 min.) and typically will vary from 1 to 96 for a single day. \(m\) is index for a day in the study period especially for weekday. Finally, _MS(i, t, m)_, the measured speed (mi/h), and _FFS(i)_ the free flow speed (mi/h) are specified for each segment.  
Figure 1(a) shows sample congestion data obtained directly from RITIS.org. The TMC segment is shown on the vertical axis and time on the horizontal axis. Congestion values are shown in the cells. Traffic flow direction is from bottom to top from TMC segment 125-10218 to TMC segment 125N04645. Figure 1(b) presents sample congestion index (CI) data.  
Figure 1: Methodology flow procedure.
# X-Band Photonic-Based Pulsed Radar Architecture with a High Range Resolution
###### Abstract  
In this paper, we propose an _X_-band photonic-based pulsed radar architecture with a high range resolution. The proposed architecture is operated as a pulsed radar by adding a Mach-Zehnder modulator (MZM) operating as an optical switch to a transmitter of a conventional photonic-based frequency-modulated continuous wave (FMCW) radar. In addition, a balanced photodetector (BPD) is employed to enhance the amplitude of the received signal and remove common-mode noise. A proposed photonic-based pulsed radar prototype is implemented to operate at a center frequency of 10 GHz, a bandwidth of 640 MHz, and a pulse repetition frequency (PRF) of 1 kHz considering the performances of an arbitrary waveform generator (AWG). The implemented prototype is verified through an indoor experiment. As a result, the positions of targets are detected in real-time with 1.6% error rates of a range accuracy and obtained the range resolution of 0.26 m.  
photonic-based pulsed radar; continuous-wave laser source; wide bandwidth Article
# Formal Modeling and Improvement in the Random Path Routing Network Scheme Using Colored Petri Nets
## 3 Material and Methods  
Simulation on Colored Petri nets is carried out with the help of formal modeling before their actual installations are carried out [14]. With the help of this technique, the behavior of the system is shown. It is observed that the significant advantages of using formal modeling are that it shows all the rules and regulations that are implemented in the existing system. One cannot ignore the importance of formal modeling in engineering structures [18]. Before the installation of the system, proper confirmation is required that shows the approaches and objectives. It is necessary to remove the ambiguity while working with the security-based structure, and formal modeling can easily do this. Numerical or mathematical complex problems can also be structured by formal methods [22]. Logicallycomplex structures can also be structured more comprehensively by using formal modeling techniques. It also provides the facility of verification and validation.  
Below, Figure 1 shows the proposed methodology of the model. The CPN tool is used to formally model in the model. The token from a source node to the destination node is sent by using calculated random path routing. First, the model has to find all the possible available paths to send the packet from source to destination. The model has traversed all the possible nodes of that path and gets the calculated path distance. Before sending the packet to the network, the model has all the routes from the source node to the sink node. Now the model has the choice to send the packet from either the shortest path or longest path. It depends upon the token to be sent. The model can send the message from the shortest path again and again if the message does not contain critical information.  
WSN is used to monitor sound, temperature, pressure, etc. Most source nodes are exposed to the cyber city, so source-location privacy (SLP) is necessary [23]. Separate path routing or multi-path routing are protocols that are used in SLP [24]. Separate path routing or multi-path routing is used to secure the location of the source node while sending the message from a source node to a sink node, but it is computationally expensive. To reduce the computational cost, the proposed modification of the current working protocol adds an additional feature is being added in this research to reduce the computational cost. SPR is computationally expensive when the longest path is selected to transfer data from a source node to a sink node. This computational cost can be minimized by first calculating the distances of all paths. After then selecting the top three shortest distances from all the distances and finally a section of one path from the top three shortest distances will  
Figure 1: Proposed model.  
decrease the computational cost. By doing this the existing protocol will become separate shortest-path routing variables mentioned in Tables 1 and 2.
## 5 Conclusions  
The purpose of this study is to describe an alternative SAMT technique to treat corneal perforation due to ocular surface inflammatory diseases. SAMT was shown to be effective for a rapid and complete resolution of corneal perforation without corneal infections and was sustained up to three months of follow up in 100% cases. This technique has the advantage of reducing the pro-inflammatory effects related to the sutures and to longer surgical procedures. Another advantage is the ease of the procedure and the little discomfort for the patients who are relieved from the use of any topical treatment. Furthermore, SAMT does not require any topical therapy since eyelids are closed by tarsorhraphy and therefore only the intrinsic properties of the amniotic membrane are exploited. The limited number of patients treated and the brief follow-up does not allow for the expression of irrefutable conclusions. Larger studies are needed to confirm the anti-inflammatory benefits of this technique in patients with ocular surface inflammatory disease. Future studies may also evaluate the possible role of SAMT in preventing corneal perforation in patients whose inflammatory ocular surface disease is no longer controlled by topical and systemic medications.  
A.M.: conception of the work, writing of the manuscript, interpretation of data, critical revision, and writing of the manuscript. L.I. and G.W.O.: writing of the manuscript, analysis of data. A.V., I.N., U.C. and M.M.: acquisition of data, writing of the manuscript. A.M.R.: supervision of the manuscript. P.A.: supervision of the manuscript, final review, and approval. All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this article, take responsibility for the integrity of the work. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Review Board (or Ethics Committee) of University of Messina (protocol code 86/19 of 2 October 2019).  
Written informed consent was obtained from participants (or their parent/legal guardian/next of kin) to participate in the study.  
The authors did not receive any financial support from any public or private sources. The authors have no financial or proprietary interest in a product, method, or material described.  
The authors declare no conflict of interest.
# Tourism Demand Forecasting Based on an LSTM Network and Its Variants
## 5 Conclusions  
The purpose of this study is to adapt an LSTM network and its variants to improve Taiwan's TD forecasting. The results show that the proposed models are more simple and effective than others to forecast nonlinear data with shocks. These techniques reveal adequate to other catastrophic situations that can affect the tourism industry.  
To overcome statistical complexities through analysing time series, this study empirically analyses the accuracy of LSTM, Bi-LSTM and GRU models applied in Taiwan's TD forecasting with shocks--namely, the SARS epidemic and the COVID-19 pandemic. The forecasting models of deep learning perform better than the other three fuzzy time series models when considering the period of catastrophic events. The results show that the use of the LSTM network and its variants can be applied to the arrival time series, given its strong autoregressive nature, using a calibration network with training data from a similar a past event--namely, the SARS epidemic. From the global error perspective, the performance of the LSTM model is slightly better than those of the Bi-LSTM and GRU in terms of the RMSE value.  
In other destinations with similar techniques, [PERSON] et al. [41] employed an LSTM network to forecast the effect of the current pandemic COVID-19 outbreak on the arrivals of Chinese tourists to the USA and Australia. [PERSON] et al. [42] ascertained the validity of the Bayesian Bi-LSTM model using the TD data of Singapore. Therefore, the robustness of TD forecasting using an LSTM network and its variants is not country-specific.  
However, the proposed models are unable to interpret TD from the economic perspective, and therefore provide little help in policy evaluation. Incorporating additional explanatory variables such as weather data and search engine data [11; 43] is promising to increase the accuracy of TD forecasting. Therefore, establishing a comprehensive ability to summarize variables selection should be the research direction going forward.  
The following are available online at [[https://www.mdpi.com/article/10.3390/a14080243/s1](https://www.mdpi.com/article/10.3390/a14080243/s1)]([https://www.mdpi.com/article/10.3390/a14080243/s1](https://www.mdpi.com/article/10.3390/a14080243/s1)), Table SI: Dataset.  
This research received no external funding.  
Not applicable.  
The data used to support the findings of this study are provided as supplementary materials.  
The author declares no conflict of interest.
# DRL-Based Dynamic Destroy Approaches for Agile-Satellite Mission Planning
## 2 Problem Description
### Variables  
Define the task set: R = {\(r_{1},r_{2},\ldots,r_{n}\)}, where \(r_{i}\) is the \(i\)-th task and \(n\) is the total number of target points. \(X=\{x_{1},x_{2},\ldots,x_{n}\}\) is the \(n\)-dimensional decision vector, where \(x_{i}\in\{0,1\}\), \(i\in\{1,2,\ldots,n\}\). The task is selected to be completed when \(x_{i}=1\). \([w_{i}^{s},w_{i}^{e}]\) and \([t_{i}^{s},t_{i}^{e}]\) can be calculated using the known satellite orbit and target information. Within the selected visible time window \([w_{i}^{s},w_{i}^{e}]\), the satellite has the capability to detect targets either through maneuvers or directly within the field of view. The task-execution time window \([t_{i}^{s},t_{i}^{e}]\) refers to the specific time during which a satellite task is executed, such as the period when an optical observation satellite takes photographs.
# Stability Analysis of the Longitudinal Slope Linear Shield Tunnel Excavation Face
## 3 Results and Discussion
### Results and Discussion of Vertical Stresses in Numerical Simulation Results  
Excavation of a shield tunnel results in stress redistribution within the surrounding soil. The vertical, horizontal, and shear stresses initially carried by the surrounding soil are released due to tunnel excavation. This sudden stress release may lead to ground subsidence or lateral deformation [26]. To better analyze the stress variations induced by shield tunnel excavation, the B-B\({}^{\prime}\) line, located 2 m in front of the excavation face center, was selected to extract vertical stresses in the soil. The vertical stress distribution in the soil 2 m ahead of the tunnel excavation was then analyzed under different slope conditions, as shown in Figure 11.  
Under all working conditions, the variation of vertical stress exhibits a double-inflection-point characteristic: the vertical stress-depth curve demonstrates significant nonlinearity. The first inflection point occurs at a depth similar to the top of the excavation face. Below this point, vertical stress decreases sharply with increasing depth, whereas  
Figure 11: Vertical stress versus depth for \(C\)/\(D\) = 1.  
Figure 10: Relationship between ultimate support ratio \(\lambda_{\text{lim}}\) and slope \(i\).  
below the second inflection point, vertical stress increases as depth increases. The region between these two inflection points corresponds to the soil loosening zone. As the tunnel longitudinal slope gradient increases, the positions of both the first and second inflection points in the soil vertical stress distribution shift upward. Under an upward (elevated) slope condition (\(i>0\)), the loosening zone of the soil, located 2 m ahead of the tunnel excavation, is positioned above the center of the excavation face. Moreover, with a larger slope gradient, the loosening zone is situated at a higher position. This observed soil displacement pattern is consistent with the results from the transparent soil test.
# Non-Cooperative Target Ranging Based on High-Orbit Single-Star Temporal-Spatial Characteristics
## 4 Discussion  
The range model developed herein was successfully deployed on a satellite platform, as illustrated in Figure 15, for the distance measurement of high-orbit threats such as space debris. The system comprises a star-sensitive camera for target acquisition and outputting rotation matrices, a tracking turntable for real-time target tracking, and a field-programmable gate array (FPGA) for computational hardware. The algorithm operates on this hardware platform, leveraging the characteristics of the satellite's motion and generating continuously changing pointing vectors, as well as its own position. This allows data acquisition at different time intervals. The model calculates the ranging results by continuously sampling two sets of data collected approximately 1 min apart. A sliding sampling method was adopted to compute results every 10 s to ensure real-time calculations.  
Figure 14: Error curve in the second group (inclination 0.0\({}^{\circ}\)–0.4\({}^{\circ}\)).  
Figure 15: Physical diagram of a ranging system. The system includes a star-sensitive camera, turntable, and calculation circuit to complete distance measurements between two objects, such as measuring the distance to space debris.  
In Equation (7), an assumption is made that the target satellite's Z-axis remains unchanged. If we further assume that the distance measurements from two observations are equal (satellite S measures the same distance at S1 and S2), then the distance can be calculated using Equations (17)-(19).  
\[z_{s1}-z_{t1}=k_{1}v_{z1} \tag{17}\]  
\[z_{s2}-z_{t2}=k_{2}v_{z2} \tag{18}\]  
\[k_{1}(v_{x1}^{2}+v_{y1}^{2}+v_{z1}^{2})=k_{2}(v_{x2}^{2}+v_{y2}^{2}+v_{z2}^{2}) \tag{19}\]  
These equations rely heavily on the variation in the pointing vector \(v_{z}\) to calculate the result. In practice, \(v_{z}\) is a normalized value, and the change in \(v_{z}\) from two observations is reflected in approximately the sixth decimal place. This situation introduces significant errors in the calculation and proves challenging to implement in an FPGA.  
The star map matching process for the star-sensitive camera is conducted in the celestial coordinate system. If all computational processes are shifted to the WGS84 coordinate system, it may be feasible to consider solving the trigonometric relationships through two observations. However, this would entail complex coordinate system transformations and could lead to significant errors in the case of extremely small angles.  
In contrast, the proposed model is straightforward, requiring no coordinate system transformations and avoiding significant errors arising from small angles. Instead, errors arise from the assumptions within the equations, and refining these assumptions can further enhance precision.
# A Method for Borehole Image Reverse Positioning and Restoration Based on Grayscale Characteristics
## 5 Conclusions  
Addressing the issue of image errors caused by probe eccentricity in panoramic imaging probes, research on probe reverse-positioning methods and image restoration  
Figure 19: Borehole image after grayscale and perspective restoration.  
Figure 18: Calculation result of perspective offset matrix.  
methods was conducted based on grayscale feature analysis. The main conclusions are as follows:  
* Basic grayscale characteristics of borehole images were analyzed. The eccentricity of panoramic imaging probes within the borehole results in uneven illumination, which is the main cause of the brightness contrast problem in borehole images. This manifests as areas of the borehole wall farther from the probe having insufficient illumination, leading to underexposed images, while areas closer to the probe have excessive illumination, resulting in overexposed images.
* Quantitative analysis was performed on the relationship between the grayscale characteristics of borehole images and probe three-dimensional position, leading to the establishment of a borehole-image grayscale feature model and the development of a panoramic probe reverse-positioning method.
* A method for the restoration of borehole image grayscale errors caused by probe eccentricity was established. Based on the grayscale feature model, a grayscale error matrix was calculated, enabling quantitative correction of grayscale errors. In practical engineering cases, the grayscale restoration method successfully corrected 31.5% of the grayscale error relative to the original grayscale range. Restored borehole images exhibit a unimodal grayscale histogram, indicating effective repair of uneven brightness caused by probe eccentricity.
* A method for perspective restoration in borehole images caused by probe eccentricity was established. A perspective error matrix was defined based on probe coordinates, enabling quantitative correction of perspective errors. In practical engineering cases, the proposed perspective restoration method successfully corrected a total perspective error of 20.665\({}^{\circ}\). The perspective deformation errors are effectively removed from restored borehole images, ensuring accurate depiction of azimuthal information.  
In conclusion, the methods proposed in this study provide effective solutions for addressing image errors caused by probe eccentricity in borehole imaging, enhancing the quality and accuracy of borehole images for rock mass structure analysis.