esa-sceva/satcom-chunk-collection huggingface dataset:
# Agricultural Waste-Based Biochar for Agronomic Applications
## 3 Biochar as a Soil Amendment
### Impacts of Biochar on Heavy Metals and Chemicals Pollution Remediation 3.6.1. Heavy Metals  
Biochar has been widely reported as an efficient material for the retention of both organic and inorganic contaminants [152]. Biochar's interface with pollutants in the soil can be controlled by many mechanisms. According to the assumptions reported in the literature, electrostatic interaction and precipitation in the case of heavy metals, and surface adsorption, partition and sequestration for organic pollutants are the main potential mechanisms controlling the biochar remediation efficiency [152; 153]. Eco-toxicology of contaminants in soil is mainly related to their bioavailability and their solubility in water, rather than their concentration [154]. Biochar addition to soil systems may affect the mobility and the bioavailability of metals either by direct interaction between metals and biochar or indirectly by inducing variations in soil properties [155; 156].The high variation in the characteristics of biomass used as a feedstock for biochar production and the diverse preparation methods and conditions allow the production of biochars with different characteristics, such as pH, CEC, organic carbon content, porosity, surface functional groups and specific surface area. Biochars will thus behave differently in the soil matrix, and then its interaction with metals and its impact on metal mobility and bioavailability will vary depending on the biochar nature (Table 3). [PERSON] et al. [157] studied the retention of inorganic contaminants on hardwood-derived biochar added in some specific sites in the UK in a 60 day-study. The results confirm the efficiency of biochar to reduce the concentration of total and bioavailable Cd and Zn in pore water, allowing the remediation of contaminated soil. Similarly, [PERSON] and [PERSON] [158] described a significant decrease in the concentration of inorganic contaminants (As, Cd, Zn) due to biochar adsorption, which significantly reduces their leachate. [PERSON] [159] investigated the effect of biochar added to sandy soil on Cu toxicity in quinoa plants (_Chenopodium quinoa_). The author observed the same biomass production for quinoa plants in soil treated by 4% biochar as in the control with the maximum Cu concentration.
## 3 Materials and Methods
### Data Set  
In this study, mobile applications of two online travel agencies in the tourism industry were selected to analyse user experiences and consumer behaviour. Booking.com was founded in 1996 and offers over 28 million accommodation properties, including over 6.6 million places to stay [26]. Expedia was founded in 1996 as an online travel agency owned by the Expedia Group. The application is used to book airline tickets, hotel reservations, car rentals, cruises, and vacation packages. Both online travel agencies can be accessed through their websites and mobile applications [27]. Mobile applications have been developed for Android and IOS operating systems and are available for customer use. The dataset in this study consists of customer comments on two applications on Google Play. Google Play is one of the largest mobile application platforms available on many devices worldwide. On this platform, which has many applications, users share their experiences with the applications by providing comments and ratings. Ser reviews on Google Play provide a data set that is comprehensive and detailed and includes different experiences [33].  
The dataset consists of 2000 reviews of Booking.com and Expedia mobile applications. The amount of data provides sufficient data saturation to ensure data reliability and validity. Thus, sentiment analysis and text mining operations are meaningful and generalisable. There are also a variety of data that can reveal different emotional states. Table 2 contains information about Booking.com and Expedia applications on Google Play.  
According to the data in Table 2, both applications have been downloaded more than 50 million times, indicating that they have a large user base. The number of comments is approximately 4 million and 800 thousand, respectively, which shows that users share their thoughts and experiences regarding the application. This provides a rich data set for analysis. The score of both applications is 4.6. This shows that users are generally satisfied with the mobile application. The fact that their launch date was 2011 shows that both companies attach importance to technology and entered the mobile application platform early [34; 35]. Table 3 shows sample comments for the two mobile applications.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Booking.com** & **Expedia** \\ \hline Number of downloads & 500 milyon+ & 50 milyon+ \\ \hline Number of comments & 4.07 milyon & 812 bin \\ \hline Score & 4.6 & 4.6 \\ \hline Release date & 4 \(\mathrm{\SIUnitSymbolMicro}\) 2011 & 10 May 2011 \\ \hline Size & 144 MB & 63 MB \\ \hline \hline \end{tabular}
\end{table}
Table 2: Google Play information of mobile applications (GooglePlay, 2024, [33]).  
The dataset was pre-processed for sentiment analysis and topic modelling. During this process, the HTML tags, special characters, and URLs were cleaned. Stop words (e.g., 'and', 'the') were removed, texts were converted to lowercase, and tokenisation was applied. The lemmatisation method was preferred when finding word roots. These steps aimed to standardise the texts and improve the accuracy of the analysis.
# Stability-Aware Geographic Routing in Energy Harvesting Wireless Sensor Networks
###### Abstract  
A new generation of wireless sensor networks that harvest energy from environmental sources such as solar, vibration, and thermoelectric to power sensor nodes is emerging to solve the problem of energy limitation. Based on the photo-voltaic model, this research proposes a stability-aware geographic routing for reliable data transmissions in energy-harvesting wireless sensor networks (EH-WSNs) to provide a reliable routes selection method and potentially achieve an unlimited network lifetime. Specifically, the influences of link quality, represented by the estimated packet reception rate, on network performance is investigated. Simulation results show that the proposed method outperforms an energy-harvesting-aware method in terms of energy consumption, the average number of hops, and the packet delivery ratio.  
wireless sensor networks; energy harvesting; multi-hops routing; geographic routing +
Footnote †: journal: Sensors
## 3 Simulations
### Two-Satellite Problem
\[\frac{-\delta}{1+\sqrt{2}}\leq\Omega_{1}\leq\frac{\delta}{1+\sqrt{2}} \tag{42}\]  
To generalize the problem and relax the limitations imposed by \(\Omega_{1,0}=0\) and \(\
u_{1,0}=0\), a further consideration can be made of their meaning. It must be observed that the values of \(\Omega_{1}\) and \(\
u_{1}\) are with respect to the value of the latitude \(\Lambda\) and longitude \(\lambda\) of the emitter. In general, the range of interest should be centered on the Nadir direction with respect to the emitter position, so their values have to be corrected considering \(\Omega_{1}\to\Omega_{1}+\lambda\) and \(\
u_{1}\to\
u_{1}+\Lambda\); then, (42) becomes as in (43). \[\frac{-\delta}{1+\sqrt{2}}\leq\Omega_{1}+\lambda\leq\frac{\delta}{1+\sqrt{2}} \tag{43}\]  
An important observation is that this way of reasoning, which permits one to pass directly from the conditions written in terms of \(\Omega_{1,0}\) and \(\
u_{1,0}\) to \(\Lambda\) and \(\lambda\), is always valid for a spherical Earth. When an ellipsoidal model is used, the condition on the right ascension of the ascending node \(\Omega_{1}\) in (43) is still valid in any case, but the condition on the true anomaly \(\
u_{1}\) needs special attention because of the distinction between the geodetic latitude and geocentric latitude. Since a variation of the results with respect to the value of the longitude \(\lambda\) is not expected (i.e., because a variation in longitude can be compensated for by a shift on the right ascension of the ascending node, obtaining the same results), in this study, it is assumed that \(\lambda=0\). The value of \(\lambda\
eq 0\) on the conditions in (43) can take place as theoretical completeness or can be of interest in simulators, where the current value of \(\alpha_{\mathrm{GR}}(t)\) in a certain time epoch \(t\) is of interest. On the other hand, the variation of results with respect to the latitude \(\Lambda\) is of interest because with an inclination of \(\pi/2\), the trajectories of the orbits tend to converge to the same point in the poles of the Earth. Another angle considered among the results of this study is the spacing angle \(\gamma_{1,2}=\angle S_{1}ES_{2}\), which can be calculated as in (44). This angle represents the spacing between the satellites \(S_{1}\) and \(S_{2}\) with respect to the position of the emitter \(E\). \[\gamma_{1,2}=\text{acos}\left(\frac{\overrightarrow{ES_{1}}^{\flat}}{\left\| \overrightarrow{ES_{1}}^{\flat}\right\|}\cdot\frac{\overrightarrow{ES_{2}}^{ \flat}}{\left\|\overrightarrow{ES_{2}}^{\flat}\right\|}\right) \tag{44}\]
# Coupled Vibration Analysis of Submerged Floating Tunnel System in Wave and Current
## 4 Parametric Influence Study
### Effect of Tube Installation Depth  
It can be seen from Figure 10 (the same working condition as Figure 3a) that the amplitude of the cables and the tube decreases with the increase of the tube installation depth, which is consistent with the results in [5]. While the installation depth is within the range of 5-40 m, the amplitude reduction rate of the cable is greater than that of the tube. Instead, once the buried depth is more than 40 m, the amplitude of the tube will decrease more prominently. The underwater installation depth of SFT should be decided in combination with the requirements for water surface navigation, wave conditions and construction difficulties.
# High-Brightness Image Enhancement Algorithm
## 1 Introduction
However, this method cannot effectively preserve local contrast and details, which is a common weakness of global tone mapping operators. The local tone mapping methods proposed in [9; 10; 11; 12; 13] are better than the global tone mapping approach used in detail preservation and dynamic range compression. [PERSON] et al. [12] used local gamma correction, which is also regarded as a kind of local tone mapping algorithm. Tone mapping algorithms in [14; 15; 16; 17; 18; 19; 20; 21] are the latest that have good processing effects in terms of image structure, detail preservation, lighting and other features. [PERSON] [15] proposed a new blind tone mapping image (TMI) quality evaluation method based on local degradation characteristics and global statistical characteristics. The texture, structure, color and other image attributes can be local or global. The extracted local and global features are aggregated into the overall quality by regression. Most color mapping operators use the human visual system, and the scene's dynamic range is displayed dynamically by a curve. For example, a model based on the sensitivity of the retina and an adjustment of the graph histogram was proposed in [21]. An asymmetric sigmoid curve is constructed to optimize this algorithm. [PERSON] et al. [22] proposed a novel tone mapping method. [PERSON] et al. [17] proposed a GAN training optimization model for the tone mapping of HDR images. The author collected a large number of tone mapping images, which existing tone mapping operators generated. An objective index is used for evaluation for all output tone mapping operators, and the algorithmic result with the highest evaluation index is selected and classified into the dataset. The model trained by the dataset can learn the best features of the tone mapping operator, so the experimental image processing effect is better than those of the existing tone mapping algorithms. [PERSON] et al. [23] proposed a new classification method for tone mapping based on the global and local tonal mapping methods commonly mentioned by other authors, frequency tone mapping approach (only the low-frequency part of the image) and split tone mapping approach (the image is divided into large areas and mapped separately for each area). This classification is more detailed than and different from those of other authors. For example, most authors classify the approaches in references [8; 9] as local tone mapping methods, but [PERSON] ranked them as frequency tone mapping operators. [PERSON] [21] proposed a new decomposition model that decomposes an HDR image into a base layer and detail layer and uses the prior information of the base layer and detail layer to minimize the halos and artifacts in the resulting image. Regarding t The rest of this paper is organized as follows: Section 2 shows the related work. Section 3 prepares and introduces our algorithm. Section 4 shows our experimental results. Section 5 is our conclusion.
###### Abstract
Feeding directly stacked image data into a traditional machine learning method and CNN ignores temporal dependencies and only uses the amplitude information of the time series. However, different crops theoretically have unique temporal profiles because they have different growth cycles. Therefore, research on extracting crop phenological features and analyzing frequency characteristics, in addition to modeling growth cycles, has been conducted to pursue more reliable and accurate recognition results. Among such studies, the Fourier transform and WT are the two most common approaches that are adopted to model crop seasonality and then extract phenological features to help the consequent identification task. Because of the complex planting structure/crop rotation and parcel size, in addition to the similarity of the spectrums between different crops, the fitted growth cycle model or the extracted phenological features may not be able to fully represent the differences between crops, and thus fail to accurately identify crop types. As aforementioned, the researches of vineyard recognition based on satellite image failed to exploit the temporal information contained in the time series of satellite images, thus, our motivation is to propose a new approach that can make not only full use of the amplitude information of each image but also the temporal information contained in whole time series, verifying both kinds of information are contributory to the identification task. The objective of this study is to integrate the advantages of the wavelet in the analysis of time series data, the superiorities of the CNN in the image recognition field, and the strengths of time series satellite image data to distinguish vineyard from other classes and made a substantial advance in mapping vineyard distribution at a regional level. The sub-objectives are as follows: (i) to verify that applying the continuous WT (CWT) to time series RS data is a stable and effective approach to obtain more information about vineyards, particularly in the frequency domain; and (ii) to confirm that feeding the scalograms generated by the CWT into the CNN is a feasible solution for identifying vineyards, and is also better than directly feeding the original time series into a traditional supervised classification method. The remainder of the paper is organized as follows: The dataset and study area are introduced in Section 2, and the details of the proposed approach are illustrated in Section 3. Following the result reported in Section 4, a discussion and conclusions are presented in Sections 5 and 6, respectively.
# Algorithmic Design of an FPGA-Based Calculator for Fast Evaluation of Tsunami Wave Danger
###### Abstract  
Events of a seismic nature followed by catastrophic floods caused by tsunami waves (the incidence of which has increased in recent decades) have an important impact on the populations of littoral regions. On the coast of Japan and Kamchatka, it takes nearly 20 min for tsunami waves to approach the nearest dry land after an offshore seismic event. This paper addresses an important question of fast simulation of tsunami wave propagation by mapping the algorithms in use in field-programmable gate arrays (FPGAs) with the help of high-level synthesis (HLS). Wave propagation is described by the shallow water system, and for numerical treatment the MacCormack scheme is used. The MacCormack algorithm is a direct difference scheme at a three-point stencil of a \"cross\" type; it happens to be appropriate for FPGA-based parallel implementation. A specialized calculator was designed. The developed software was tested for precision and performance. Numerical tests computing wave fronts show very good agreement with the available exact solutions (for two particular cases of the sea bed topography) and with the reference code. As the result, it takes just 17.06 s to simulate 1600 s (3200 time steps) of the wave propagation using a 3000 \(\times\) 3200 computation grid with a VC709 board. The step length of the computational grid was chosen to display the simulation results in sufficient detail along the coastline. At the same time, the size of data arrays should provide their free placement in the memory of FPGA chips. The rather high performance achieved shows that tsunami danger could be correctly evaluated in a few minutes after seismic events.  
algorithm implementation; high-level synthesis; tsunami wave; numerical modeling +
Footnote †: journal: _Algorithms_  
[PERSON], [PERSON], [PERSON], [PERSON], [PERSON], M. Algorithmic Design of an FPGA-Based Calculator for Fast Evaluation of Tsunami Wave Danger. _Algorithms_**2021**, 14, 343. [[https://doi.org/10.3309/a14120343](https://doi.org/10.3309/a14120343)]([https://doi.org/10.3309/a14120343](https://doi.org/10.3309/a14120343))
## 2 Materials and Methods
### Back-Trajectory Analysis of Meteorological and Satellite Data  
To identify the source area of long-range transport air parcels, a concentration weighted trajectory (CWT) was applied with CO and CO\({}_{2}\). Backward trajectories arriving in the sampling area were obtained using the HYSPLIT model with GDAS1 meteorological data. To further perform CWT analysis, 120 h backward trajectories that arrived at 1000 m above ground level (AGL) were used. CWT with CO/CO\({}_{2}\) ratio was calculated as follows [16; 17]:  
\[C_{ij}=\frac{\sum_{n=1}^{k}C_{n}t_{ijn}}{\sum_{n=1}^{k}t_{ijn}} \tag{1}\]  
where \(C_{ij}\) was the average ratio of grid _ij_; \(k\) was the total number of concentrations and trajectories; \(C_{n}\) was the hourly CO/CO\({}_{2}\) ratio (ppb/ppm); and \(t_{ijn}\) was the residence time of the trajectory through grid _ij_. The trajectory distribution grid had a 1.0\({}^{\circ}\times 1.0^{\circ}\) resolution and a boundary of 110-140\({}^{\circ}\) E and 25-50\({}^{\circ}\) E.  
Data from satellites and meteorology were analyzed during the long-range transport (LRT) period. Aerosol optical depth (AOD) of Terra and Aqua/MODIS and CO Column of Sentinel-SP/TROPOMI were used as satellite data [18; 19; 20]. Data passing through the Korean peninsula satellite orbit during the LRT period were calculated using the arithmetic mean [21]. Data on wind direction and speed in 850 hPa from ERA5 were used as meteorological data in this study. ERA5 data were calculated using the arithmetic mean every three hours during the LRT event period to indicate an overall current pattern of Northeast Asia. During the measurement period, MOD04/MYD04 satellite data were used. This parameter data was named \"Optical_Depth_Land_And_Ocean\". An average MODIS was shown with an arithmetic mean after rearranging 0.25 degrees of spacing grids.
## 7 Telemedicine and AI Support Systems  
### Remote Medical Assistance  
Telemedicine bridges the gap between spacecraft crews and Earth-based specialists, enabling support for ocular emergencies through high-resolution imaging tools, such as anterior segment cameras and fundus photography devices. These systems facilitate detailed evaluations that can be transmitted for expert consultation, particularly for diagnosing conditions like corneal abrasions, foreign bodies, or retinal changes [77; 83]. However, as missions extend into deep space, communication delays of up to 20 min necessitate onboard diagnostic autonomy and advanced remote healthcare solutions [84].  
NASA's early applications of telemedicine during the Apollo and Skylab missions integrated telemetry, biosensor harnesses, and remote imaging to monitor astronaut health in real time. These technologies have evolved into modern tools like the Bio-Monitor and Bio-Analyzer, which provide near-instantaneous diagnostic data onboard spacecraft [85; 86]. In ocular health, onboard diagnostic systems combined with AI and telemedicine frameworks allow astronauts to perform initial assessments and interventions autonomously when Earth-based consultations are delayed.  
Multifunctional modular imaging systems, such as point-of-care OCT and ultrasound devices, enhance diagnostic accuracy while optimizing resource allocation. These tools are critical for addressing emergencies like retinal detachments or corneal abrasions, which require immediate intervention to prevent vision loss [86; 87]. The diagnosis and treatment of corneal abrasions would be greatly augmented using such imaging systems. Although retinal detachments could be diagnosed, the treatment options during space missions would be very limited. AI-enabled decision support further empowers astronauts by providing tailored treatment pathways, reducing dependence on Earth-based expertise, and ensuring timely management of ocular emergencies [84,88].  
Advanced telecommunication systems, including satellite networks like the Indian Data Relay Satellite System (IDRSS), enhance contact between astronauts and ground-based medical teams. These systems enable real-time consultations and data transmission, significantly improving emergency care coordination [88]. Virtual medical avatars--a novel telemedicine concept--combine biosensor data with AI-driven analytics to create interactive diagnostic and decision-support tools for autonomous health management in deep space [87].  
By integrating telemedicine with autonomous diagnostic and therapeutic systems, future missions can achieve a new standard of health management for deep-space exploration. These innovations equip astronauts to address ocular emergencies and broader health challenges, enhancing the safety and success of long-duration missions while advancing remote healthcare technologies for terrestrial applications.