esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Discussion
### Assessment of the Optimal Dates and Required Observation Periods for Classification  
The classification accuracy using 14 peak days (OA = 0.90, Kappa = 0.87) (Figure 9) was lower than that using all variables (OA = 0.93, Kappa = 0.92); yet good classification accuracy continues to be obtained. The number of peak days (14) almost coincided with the most frequent value (mtry = 15) of the number of variables determined by tuning during classification.  
On a single date, Kappa showed fair (0.20-0.40), making good classification impossible (Figure 9). Therefore, multi-date images are required for mapping subtropical agricultural areas. The most efficient approach for classification is to use five images in a two-year observation period (Figure 9): Two images of the spring and summer sugarcane plantings in each year, and one image just before the harvesting in the second year. The first four images may contribute to the identification of sugarcane and other classes, and of sugarcane cropping practices. We infer that the last image would contribute mainly to distinguish sugarcane (in particular, ratoon and spring planting) from purple yam, which are all harvested mainly at this time of the year and have little vegetation cover. Using these images, excellent classification performance (Kappa >0.80; Figure 9) was obtained.  
The images of the harvest season did not contribute to achieve high classification accuracy (Figures 7 and 8). This is supported by the poor classification accuracy for the similar crops based on images taken in the harvest season [37]. The classification accuracy in the study of [PERSON] et al. [37], who used combined images from various medium spatial-resolution satellites (8-20 m) for an area similar to ours, was lower than in our study (OA = 0.64 < 0.93, Kappa = 0.47 < 0.92). This difference may be because they used only images taken in harvesting (January to March) and summer (July to September), but not in the spring planting season. Furthermore, these authors intentionally used images with low cloud cover, and may have missed the appropriate timing for classification because of the observation frequency. The greatest advantage of creating a time series by high-frequency earth observation using a satellite constellation is the improved probability of obtaining NDVI values at a time suitable for classification.
# Review on Semi-Fragile Watermarking Algorithms for Content Authentication of Digital Images
## 1 Introduction
We classify several typical semi-fragile watermarking algorithms according to whether they have the ability of recovery, and then classify them further in accordance with the spatial domain and the transform domain. Additionally, we make four tables to compare the basic information and performance of these mentioned algorithms, including size of host images, block size or number of layers, content-based watermark or not, embedded position, the type of non-malicious tampering that the algorithms can resist, the quality factor (QF) of the JPEG (joint photographic experts group) compression, the peak signal-to-noise ratio (PSNR) of the watermarked image and recovered image, and the ability for tamper detection and location. Through this paper, readers can have a more comprehensive understanding of semi-fragile watermarking techniques, and can grasp the basic information and performance of a variety of semi-fragile watermark algorithms used for image authentication easily so that they can access to this area more quickly. The rest of this paper is organized as follows. Section 2 presents the basic principles and characteristics about semi-fragile watermarking algorithms. Several kinds of common attacks are included in Section 3. Section 4 introduces the evaluation indexes of various algorithms. A literature review on semi-fragile watermark is presented in Section 5. Conclusions and future development are given finally in Section 6.
# A Comprehensive Review of Sensor-Based Smart Building Monitoring and Data Gathering Techniques
###### Abstract
* Air quality monitoring--delivers real-time data on temperature, humidity, CO2 level, volatile organic compounds (VOCs), and atmosphere pressure. This allows building owners to create a healthier and more comfortable indoor climate for tenants. Collecting temperature data from across the building enables managers to identify hot and cold spots, allowing them to take proactive measures to reduce energy consumption, CO2 emissions, and cost. In this paper, we explore and compare solutions for measuring building parameters to evaluate opportunities for designing an effective smart building monitoring system. We consider the following aspects:  
* The behaviors of building occupants;
* Sensor allocation;
* Implementation complexity and precision of the studied methods. The review process was initiated by identifying a range of review articles focused on facility management. For topics that required a more in-depth understanding, extensive research was conducted by sourcing multiple papers that provided a more detailed exploration of the subject matter. These comprehensive papers offered a granular level of detail, enriching the overall review. The remainder of this paper is organized as follows: Section 2 provides an overview of the architecture and main characteristics of a smart building monitoring and control system; Section 3 describes how to measure and manage building parameters within the scope of smart building applications; Section 4 describes occupancy sensing techniques; Section 5 gives an introduction to data gathering and processing techniques; Section 6 summarizes the findings of this study; Section 7 provides the conclusions and suggests areas for future research.
## 5 Conclusions  
In this paper, we addressed the complex problem of jointly optimizing caching strategies, computation offloading, and UAV trajectories in dynamic UAV-assisted vehicular networks. Due to the problem's coupled, distributed, and constrained nature, traditional optimization and existing multi-agent deep reinforcement learning (MARL) methods struggle with stability and convergence in such environments. To tackle this, we proposed a novel MARL framework by modeling the problem as a Dec-POMDP and developing a MAPPO algorithm that adheres to the CTDE paradigm. We innovatively introduce system efficiency as a unified performance metric, and with this as the primary optimization objective, we balance multiple performance indicators such as cache hit rate, task delay, energy consumption, and fairness. Extensive simulations demonstrated that our MAPPO-based approach outperforms baselines such as MADDPG, MAAC, Greedy, and Random, showing clear gains in cumulative rewards, cache hit rate, system efficiency, and task delay reduction, while effectively controlling UAV energy consumption. Sensitivity analysis across hyperparameters and system scales further confirmed its robustness. This work validates the potential of Dec-POMDP modeling and MAPPO enhanced by innovative state-space design and reward shaping mechanisms in solving dynamic, distributed resource management problems. Future directions include addressing realistic mobility patterns, large-scale scalability, and wireless interference, potentially incorporating predictive models to manage uncertainty.  
Conceptualization, Y.W. and Y.H.; methodology, Y.W. and Y.H.; software, Y.W. and Y.H.; validation, Y.W., Y.H. and Z.W.; writing--original draft preparation, Y.W. and Y.H.; writing--review and editing, Y.W., Y.H. and C.X.; visualization, Y.W. and Y.H.; supervision, C.X. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available because the research data are confidential.  
The authors declare no potential conflicts of interest.  
Figure 12: Sensitivity analysis of objective function to reward weights.
## 4 Emerging Biogas Upgrading Technologies
### Separation via a Solid Agent
#### 4.2.2 Biochar  
Biochar was recently proposed for its utilization in AD due to its capacity to improve the methane yield and increase methane content in biogas while reducing H\({}_{2}\)S concentrations [119]. Moreover, biochar derived from biomass pyrolysis has been shown to enhance AD performance by providing microbial habitats, reinforcing buffering capabilities, and promoting bioelectrical connections between fermentative bacteria and methanogens [120]. The use of an appropriate amount of biochar reduces the lag phase, accelerating the AD process and improving methane production. CO\({}_{2}\) can be separated from CH\({}_{4}\) through adsorption, employing a porous solid with a high specific surface area. Biochar is considered a promising, environmentally friendly alternative in this context [121]. The high porosity and extensive specific surface area of biochar favor the effective capture of CO\({}_{2}\); likewise, the presence of a slightly alkaline pH facilitates the conversion of CO\({}_{2}\) into bicarbonate or carbonate [106]. Biochar is a pyrogenic material rich in carbon generated from carbon-neutral sources [122]. It can be obtained from several biomass feedstocks, and its effects will vary accordingly. Biogas extracted from sludge anaerobic digestion typically comprises 50-70% CH\({}_{4}\), 30-50% CO\({}_{2}\), and small quantities of H\({}_{2}\)S, NH\({}_{3}\), siloxanes, H\({}_{2}\), N\({}_{2}\), and O\({}_{2}\). Utilizing biogas on-site for combined heat and power (CHP) generation necessitates purification and enhancement (e.g., removing CO\({}_{2}\), H\({}_{2}\)S, water, and other impurities) to achieve high-quality biomethane suitable for pipeline distribution (with CH\({}_{4}\) content > 96% and a heating value > 37 MJ/m\({}^{3}\)) [49]. Additionally, corn stover biochar serves as a supplementary nutrient source, offering calcium, magnesium, and iron for the anaerobic digestion process of sludge [49].  
Some results are shown in Table 7. For example, a study performed by [PERSON] et al. [123], using corn stover biochar inside a digester with WWTP sludge as its feedstock, obtained biomethane with a concentration of more than 90% methane and less than 5 ppb H\({}_{2}\)S. When using pine biochar, methane content of up to 92.3% and 79% was obtained during AD at mesophilic and thermophilic temperatures, respectively; meanwhile, for white oak biochar, those values were 89.8% and 78.5% [119]. Biochar can also be used in a separated unit from a digester for H\({}_{2}\)S removal; [PERSON] and co-authors used leaf waste biochar and obtained a reduction in H\({}_{2}\)S concentration of 84% (from 1254 ppm to 201 ppm) [124]. An extra advantage of using biochar in a digester is that the obtained digestate is enriched with nutrients, such as K, Ca, Mg, Fe, and S (the concentration depends on the biochar and biogas feedstock) [119; 123].
## 2 Materials and Methods
### Methods and Algorithms  
#### 2.3.1 Homogeneous Transformation Matrix  
The homogeneous transformation matrix [49] is used to represent the orientation and position of a coordinate system within a \"world\" coordinate system. Sub-transformations, such as rotation matrix, translation, perspective, and global scale, are appropriately combined into a single three-dimensional homogeneous transformation matrix. Figure 3 shows the homogeneous transformation matrix and its sub-transformations.
# Passive Radar-Based Parameter Estimation of Low Earth Orbit Debris Targets
## 5 Simulations
### Moving Target over a Forward Scatter Receiver Array
#### 5.2.4 Discrete Doppler Relationship  
During the time instance while the Doppler at \(R_{x1}\), \(f_{D,R_{x1}}=0\) Hz, the Doppler at \(R_{x2}\), \(f_{D,R_{x2}}=\Delta f\). Furthermore, as highlighted by the black circles in Figure 8b, the Doppler values at the remaining receivers are \(f_{D,R_{x3}}=2\Delta f\) and \(f_{D,R_{x3}}=3\Delta f\). Therefore, a pattern of discrete Doppler shifts is recorded at subsequent receiver elements. This pattern can be summarized by Equation (20) when the reference receiver records zero Doppler shift. The shifts at the adjacent receivers are given by  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Velocity, \(v\) & 7.5 km/s \\ Altitude, \(h\) & 400 km \\ Baseline, \(L\) & 20,200 km \\ Incident Wavelength, \(\lambda\) & 0.1905 m \\ Element spacing, \(d\) & \(\lambda/2\) \\ Horizontal Distance, \(D\) & \(\pm 10^{3}\cdot\lambda/2\) \\ \hline \hline \end{tabular}
\end{table}
Table 1: Simulation Parameters.  
Figure 8: (**a**) Doppler shift measurements as a target passes over a single receiver; (**b**) Doppler shift measurements as a target passes over a linear receiver array.  
\[f_{D,R_{m}}=(n-1)\cdot\Delta f=(n-1)\cdot f_{D,R_{s2}} \tag{20}\]  
Knowledge of the discrete Doppler behavior may assist data preparation and analysis processes as data periods with no BCEs may be removed.
# Toward Integrated Satellite Operations and Network Management: A Review and Novel Framework
## 2 State of the Art
### Research Insights and Challenges
\begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Operation Type** & **Current Limitations** & **CMS Framework Contributions** \\ \hline \multirow{8}{*}{Sporadic Connectivity Operations [40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66]} & **Mission-Specific Solutions**: Space agency tools tailored to specific missions. Many frameworks discontinued or outdated. **Propiterary Limitations**: Commercial solutions are closed-source. No adaptability across different operators. **Eo-Focused Approaches**: Most research targets Earth observation. Limited telecommunications applications. Semi-manual procedures still prevalent & **Open \& General Framework:** Publicly available integrated solution. Suitable for various scenarios and operators. **Automated Operations:** Eliminates manual intervention requirements. Handles dynamic scenarios effectively. **Automated Systems:** Extends **DecSODs task scheduling for telecom. Incorporates QoS and 3 GPP procedures. Bridges satellite and network operations. **Automated Operations:** Translates SDN/MANO to schedulable tasks. Aligns with satellite operational practices. **Enhanced Automation:** Prevents system overload from control commands. Enables automated NFV deployment. **Critical Framework:** Scheduled operations and resource prediction. Bridges theoretical concepts with operational reality. \\ \cline{2-3}  & **Terestrical-Centric Approaches:** Based on terrestrial network principles. Insufficient satellite constraint integration. **Limited Automation:** MANO NFV deployment not automated. Requires manual orchestration processes. **Theoretical Implementations:** Multi-layered concepts lack real deployment. Continuous monitoring assumptions unrealistic. & **Satellite-Aware Integration:** Translates SDN/MANO to schedulable tasks. Aligns with satellite operational practices. **Enhanced Automation:** Prevents system overload from control commands. Enables automated NFV deployment. **Critical Framework:** Scheduled operations and resource prediction. Bridges theoretical concepts with operational reality. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Management solutions in the literature.
# A Time-Optimal Continuous Jerk Trajectory Planning Algorithm for Manipulators
## 1 Introduction
In this manner, the velocity, acceleration and jerk constraints of each joint are transformed into the control vertex constraints of the B-spline trajectory. Then, the shortest running time of traversing the joint position sequence is set as the objective function, and the sequential quadratic programming method is used to solve the nonlinear constraint optimization problems, to plan the time-optimal jerk continuous trajectory. Finally, the effectiveness of the proposed trajectory planning method is verified through the simulations. The major contributions of this paper are as follows:  
1. The trajectory based on the 7 th-order B-spline interpolation curve is designed, which ensures that the joint jerk is fully smooth, and the joint start-stop speed, acceleration and jerk can be set, overcoming the shortcoming that the trajectory interpolation method based on the quadratic polynomial plus cosine function needs to force the pulsation at the node to be 0. 2. By using the convex hull property of the B-spline curve, the kinematic constraint of the manipulator is transformed into the control vertex constraint of the trajectory curve. The sequential quadratic programming method is used to solve the time-optimal trajectory planning problem, and then the time-optimal pulsating continuous trajectory is planned. 3. The proposed strategy can also be used for online obstacle avoidance trajectory planning in complex environments and optimal trajectory planning with energy or time-energy performance as the optimization index. The remainder of this paper is organized as follows: In Section 2, we introduce the construction idea of the jerk continuous trajectory. In Section 3, we transform the joint kinematic constraint into the control vertex constraint of the B-spline trajectory curve, to avoid the semi-infinite constraint problem of sampling and testing the trajectory curve, and then solve the time-optimal trajectory planning of the manipulator in Section 4. We present the simulation verification and result analysis in Section 5, and we summarize this paper and look forward to the future work in Section 6.
## 5 Conclusions  
This investigation examined the use of integrated ground-based meteorological variables and satellite-derived host plant variables to build a prediction model for population occurrence of BPH during the rice crop dry season in the central plain of Thailand. MLR, ANN, and RF models were developed based on these variables. MLR was employed to investigate the prediction ability of weather variables alone or in combination with host-plant phenology, while ANN and RF models were established to enhance the prediction performance of the model compared to MLR.  
Tmin without lag and NDVI at a one-month lag were selected as the major factors in the MLR model based on their high correlation coefficients. Moreover, we found that the combination of these variables yielded higher accuracy in predicting light trap catches than weather variables alone. Use of ANN (with a 10-5-1 structure) and RF (with number of trees: 500) yielded a more efficient performance than the MLR in terms of R\({}^{2}\) and RMSE in testing (ANN model: R\({}^{2}\) = 0.770, RMSE = 1.686; RF model: R\({}^{2}\) = 0.754, RMSE = 1.737; and MLR model: R\({}^{2}\) = 0.645, RMSE = 2.015) dataset validation.  
In summary, an ANN model integrating ground-based meteorological variables and satellite-derived host plant variables can be utilized for short-term forecasting of the peak abundance of BPH, to be applied in timely management of crop pests after reasonable validation with different location and seasonal data. We expect that these results can be applied in conjunction with the satellite-based rice monitoring system developed by the Geo-Informatic and Space Technology Development Agency (GISTDA; [[http://rice.gistda.or.th](http://rice.gistda.or.th)]([http://rice.gistda.or.th](http://rice.gistda.or.th))) to support an effective pest early warning system.  
Conceptualization, S.S. and M.N.; data curation, S.S.; formal analysis, S.S. and M.N.; methodology, S.S.; software, S.S.; validation, S.S.; writing--original draft preparation, S.S.; writing--review and editing, S.S., M.N., N.K.T. and P.S.; supervision, M.N., N.K.T. and P.S.  
This research received no external funding.  
We are thankful to [PERSON], Agricultural Research Officer (Professional Level), Chai Nat Rice Research Center for providing the BPH light trap catches data and [PERSON], Geo-Informatic and Space Technology Development Agency (Public Organization) for supporting the BP-ANN Python script.  
The authors declare no conflict of interest.
## 4 Discussion and Conclusions  
A decrease of Cl\({}^{-}\) intracellular concentration has been showed to be directly linked to malignant proliferation [12], and a decrease of Na\({}^{+}\) intracellular concentration is able to hyperpolarise the cell membrane, with a determinant consequence on the mitotic arrest [51, 52, 53, 54, 59, 70, 71, 72]. Hyperpolarisation determines an activation of the Ca\({}^{2+}\)-K\({}^{+}\) channel which increases the Ca\({}^{2+}\) intracellular concentration [12, 73], with the consequence that the Ca\({}^{2+}\)-K\({}^{+}\) channel results a fundamental controller of the membrane electric potential. In this context, also water outflow was shown to play a fundamental role in metastasis activity [12, 74].  
Proteins play a fundamental role in ion transport. Proteins in the cytosolic can be modified in their functions by phosphorylation or dephosphorylation. An ion actively crosses the membrane against its electrochemical potential, whereby the necessary energy is derived either from the hydrolysis of ATP, or from the movement of a co-transported, or coupled ion along its electrochemical gradient. In this context, the role played by the H\({}^{+}\)-ATPase is fundamental, because it moves positive charges into the cell, while it generates large membrane voltage (inside negative and outside positive) and a pH gradient [75, 76, 77, 78]. Protein phosphorylation is an important cellular regulatory mechanism, because many enzymes and receptors [50, 79, 80] are activated or deactivated by phosphorylation by involving kinases and phosphatases. Moreover, kinases are responsible for cellular transduction signalling [81, 82, 83, 84].  
In this paper, the theoretical explanation of the ions role in relation to the cell membrane potential has been obtained by introducing the non-equilibrium thermodynamic approach. It is the first fundamental step for a new approach in cancer researches. Indeed, it highlights:  
* The relation between cell membrane potential and temperature.
* The relation between cell membrane potential and ions fluxes.
* The spontaneous symmetry breaking in the Onsager relations as a fundamental transition between the Seebeck-like effect and the Peltier-like effect in the cell membrane.
* The link between life and the transition from a Seebeck-like effect to a Peltier-like effect and viceversa.  
Conceptualization, U.L.; methodology, U.L. and G.G.; software, G.G.; validation, U.L. and G.G.; formal analysis, U.L.; investigation, G.G.; resources, U.L.; data curation, G.G.; writing--original draft preparation, U.L. and G.G.; writing--review and editing, U.L. and G.G.; visualization, G.G.; supervision, U.L.; project administration, U.L.; funding acquisition, U.L. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The authors declare no conflict of interest.