esa-sceva/satcom-chunk-collection huggingface dataset:
# Electrodegradation of Selected Water Contaminants: Efficacy and Transformation Products
## 3 Results and Discussion
### Removal Efficiency, Kinetic Analysis, and Energy Consumption of Electrooxidative Treatment
#### 3.2.2 Kinetic Analysis of EO Treatment
(**b**) Comparison of experimental data with first- and second-order kinetic models for DBP degradation with H\({}_{2}\)SO\({}_{4}\) as a supporting electrolyte. the most promising for degrading persistent phthalates, especially when coupled with electrochemical or UV-based activation. Collectively, these studies reinforce the strong kinetic performance and mechanistic validity of the sulphate radical pathway observed in our BDD-based electrochemical system. [PERSON] et al. [50] extensively reviewed the mechanisms of the electrochemical generation of persulphate and sulphate radicals in aqueous media, emphasizing the key influence of current density, electrode material, and electrolyte composition on radical yield and reaction efficiency [50]. Their analysis highlighted that higher current densities (>20 mA/cm\({}^{2}\)) typically favour increased persulphate generation but can also lead to side reactions and increased energy consumption. In comparison, our study achieved efficient DBP degradation at a relatively low current density (10 mA/cm\({}^{2}\)), suggesting that the use of a BDD anode combined with an optimized acidic electrolyte (H\({}_{2}\)SO\({}_{4}\)) enables effective radical generation at milder conditions. Additionally, while [PERSON] et al. [50] identified BDD as one of the most effective anodes for sulphate radical formation due to its high overpotential for oxygen evolution, our findings further validate this by demonstrating rapid DBP degradation without the need for metal additives or external oxidants.
# Development of the First Portuguese Radar Tracking Sensor for Space Debris
## 2 Implemented System  
In order to support and consolidate the pooling of national resources to prepare for the establishment of a SST sensor network, Instituto de Telecomunicacoes initiated in 2019 a major upgrade of its Cassegrain Antenna located in Pampilhosa da Serra, Portugal. Attached to the antenna will be a complete ground-based radar system, named ATLAS, operating in the C-band (5.56 GHz).  
ATLAS is a monostatic pulse radar using solid state power amplifiers (GaN) with a peak output power of 5 kW for tracking debris objects in LEO. Regarding the receiver side, the system is fully coherent with detection and processing fully in the digital domain with a bandwidth of 50 MHz and with the capacity to detect Doppler velocities up to 10.79 km/s. The architecture, depicted in Figure 1, is highly inspired in the HAX/Haystack system [24] developed by NASA, which is a very successful ground-based radar used for debris detection and tracking. The system follows the use of Commercial-Off-The-Shelf (COTS) technologies and Open Systems (OS), which enables a major downstream cost reduction in the development and maintenance of the system [25]. Table 1 provides a comparison between ATLAS and other tracking radars currently used in SSA activities.
# WDS-YOLO: A Marine Benthos Detection Model Fusing Wavelet Convolution and Deformable Attention
## 4 Experiments
### Experiment Results  
#### 4.2.1 Ablation Experiment  
To validate the effectiveness and rationale of the proposed improvements, we conducted a series of ablation studies using identical datasets, experimental platforms, and model parameters for evaluation. The detailed results are summarized in Table 2, which reports Precision (P), Recall (R), and mAP@50 (mean Average Precision at 50% IoU threshold), standard metrics for evaluating detection performance. A checkmark (\(\surd\)) denotes the application of each respective enhancement strategy.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Phase** & **Total Instances** & **Holothurian** & **Echinus** & **Starfish** & **Scallop** \\ \hline Training & 40,107 & 4502 & 20,356 & 6473 & 8776 \\ Validation & 5660 & 619 & 2780 & 947 & 1314 \\ Test & 11,645 & 1250 & 5488 & 1844 & 3063 \\ \hline \hline \end{tabular}
\end{table}
Table 1: The distribution of the URPC2020 dataset across training, validation, and test sets.  
Figure 7: Sample images from URPC2020 dataset.  
As shown in Table 2, the three proposed improvements--WTConv based on wavelet transform, DASPPF, and SF-PAFPN--significantly enhanced the model's detection performance. First, the WTConv-enhanced backbone achieved a 0.2% improvement in mAP@50, with a 13.3% reduction in parameters and a 4.2 FPS increase in detection speed. This demonstrates enhanced feature extraction capability for marine benthos objects in complex backgrounds, while achieving an optimal balance among parameter efficiency, detection speed, and accuracy. Second, the DASPPF module strengthened feature correlations in important target regions while suppressing irrelevant background areas, resulting in an mAP@50 improvement to 84.3%. Third, the SF-PAFPN module significantly improved small object detection, with a 1.2% increase in mAP@50, along with enhanced precision and recall rates.  
While combining SF-PAFPN and DASPPF improved the detection accuracy, it inevitably increased the model parameters. Integrating WTConv with SF-PAFPN achieved 84.9% mAP@50, representing a 1.4% improvement over the baseline and 1.2% over SF-PAFPN alone, while reducing the parameters by 12.1%. This indicates WTConv's capability to mitigate parameter inflation from large-kernel convolutions in SF-PAFPN while further enhancing accuracy.  
Finally, the WDS-YOLO model incorporating all three improvements achieved a 2.1% higher mAP@50 than YOLOv8n, with only 0.2 M additional parameters, maintaining lightweight characteristics despite a slight speed reduction. These results demonstrate the effectiveness and compatibility of the developed improvements for marine benthos tasks.
# Estimating Tail Probabilities of Random Sums of Phase-Type Scale Mixture Random Variables +
## 1 Introduction
[10] addressed this issue and proposed a methodology which can be easily adapted to compute geometric random sums of scale mixture of PH distributions. Their approach is based on an infinite series representation of the tail probability of the geometric sum which can be computed to any desired precision at the cost of increased computational effort. In this paper, we explore an obvious alternative approach: rare-event estimation. More precisely, we propose and analyse simulation methodologies to approximate the tail probabilities of a random sum of scale mixture of PH-distributed random variables. We remark that since the CDF and PDF of a distribution in the \(W\)-mixture of PH distributions class is effectively not available, most algorithms for the heavy-tailed setting discussed above cannot be implemented. Our approach is to use conditioning arguments and adapt the Asmussen-Kroese estimator proposed in [7]. The Asmussen-Kroese approach is usually not directly implementable in our setting because the CDF of the product \(W_{i}\,X_{i}\) is typically not available. We address this issue using a simple conditioning argument on either the PH random variable \(X_{i}\) or the scaling random variable \(W_{i}\), thereby simply simulating the PH distribution and using the CDF of \(W_{i}\) or simulating the scaling distribution and using the CDF of \(X_{i}\). Moreover, we explore the use of importance sampling (IS) on the last term of the summands. The key contributions of this paper are as follows:  
* Developing a number of rare event simulation methodologies;
* Proving the efficiency of proposed estimators under certain conditions;
* Exploring the proposed estimators through various numerical experiments. The remainder of the paper is organised as follows. In Section 2, we provide background knowledge on PH distributions and scale mixture of PH distributions. In Section 3, we introduce the proposed algorithms. In Section 4, we prove the efficiency of the estimators proposed. In Section 5, we present the empirical results for several examples. Section 6 provides some concluding remarks and an outlook to future work.
# Acquisition and Processing of UAV Fault Data Based on Time Line Modeling Method
## 3 The Design of Simulation Environments and Simulation Tasks
### Simulation of Accelerometer Faults  
(1) Simulation parameter configuration when simulating the accelerometer failure  
Both accelerometer one and accelerometer two were disabled in the simulation environment by setting SIM_ACCEL1_FAIL and SIM_ACCEL2_FAIL to 1. Since the drone cannot acquire correct acceleration information, it cannot derive a current, correct position estimate and heading estimate to simulate accelerometer failure. Some parameters of the simulation environment when simulating Accelerometer failure are shown in Table 2.  
(2) The Simulation of Accelerometer Failure  
By changing the parameters of the accelerometer during the UAV flight, the UAV accelerometer's failure state was simulated. The trajectory of the UAV under QGround-Control is shown in Figure 11. Accelerometer failures occurred from point A to point B and from point C to point D. It can be seen that after the drone fail-safe mechanism was disabled and the drone lost acceleration information, the flight trajectory presented an unstable state. The rest of the flight track accelerometers were working normally, and the flight track of the UAV presented a stable state.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Value** & **Description** \\ \hline SIM\_WIND\_T\_ALT & 60.000000 & Full wind height \\ FS\_EKF\_THRESH & 0/1 & Disable/enable fail-safe mechanism \\ SIM\_ACCEL1\_FAIL & 0/1 & Clear/simulate accelerometer 1 fault \\ SIM\_ACCEL2\_FAIL & 0/1 & Clear/simulate accelerometer 2 fault \\ \hline \hline \end{tabular}
\end{table}
Table 2: Some parameter settings in accelerometer fault simulation.  
Figure 10: The status change of the drone when GPS fails.  
In order to better understand the impact of accelerometer failure on the UAV, the status information of the UAV, as shown in Figure 12, was extracted after the flight. As shown in Figure 12a, the accelerometer failure occurred when the TimeStamp was about 250,000 Ms to 390,000 Ms, and the GPS speed of the drone had abnormal vibrations. The reason is that after the drone lost accurate position estimation after the accelerometer failure, the UAV tried to maintain the current flight trajectory through past position information so that the speed will be unstable. Due to the change in speed, as shown in Figure 12b, the UAV's Circular Angle also appeared abnormal. As shown in Figure 12c, after the accelerometer failure, the acceleration information of the drone in the x, y, and z axes were completely lost. Since accurate position estimation could not be obtained through the acceleration information, so the roll angle and pitch angle were also abnormal during this period.  
Figure 11: The flight trajectory of the UAV in the state of accelerometer failure.  
Figure 12: State change of drone with accelerometer failure.
# Ultrasound in Telemedicine: A Brief Overview
## 3 Results
### Cost Efficiency  
In the scenario of real-time tele-ultrasound consultations and tele-education, savings in the conventional costs of patient transfer (e.g., transfer from GP to clinic) and human resources (e.g., clinical specialist in remote areas) need to be balanced against accruing telecommunication costs. An Australian study demonstrated that tele-ultrasound can result in a net saving of AUD 6340 and, at the same time, enabled almost four times the number of consultations than if the service had not been available [19]. In this study, a  
Figure 3: Ultrasound image from a tele-didactic ultrasound teaching study on abdominal ultrasound from the medical faculty of the University of Bonn, Germany. (**A**) Peer tutor, (**B**) student exercising ultrasound on another student, (**C**) ultrasound image of the right kidney, which will be improved via tele-guidance by the peer tutor. An experienced ultrasonographer is also online in order to assist if any questions arise.  
real-time fetal tele-ultrasound consultation service had been implemented and integrated into the daily clinical practice. Patients in Townsville could be assessed by subspecialists in Brisbane, 1500 km away, using the service. Ninety percent of the babies born during the 90 tele-ultrasound consultations for the first 71 patients showed good outcome data. The existence of all key anomalies and diagnoses was established in this study. Without telemedicine, 24 of the 71 patients would have been physically referred to Brisbane. Thus, this study underlined the cost effectiveness of the practice in a rural region.  
As technology improves, wireless networks and cell phone access become more reliable, and companies such as Apple, Skype and many start-ups provide commercially available real-time audiovisual software in compliance with patient protection laws such as the American HIPAA (\"Health Insurance Portability and Accountability Act\"), making tele-ultrasound a feasible proposition.  
Cost is a commonly expressed concern regarding tele-ultrasound with a special emphasis on the need for affordable tele-ultrasound platforms to make its use feasible. In the literature, numerous studies have used telemedicine platforms with open-source, low-cost, commercially available software such as over-the-counter hardware and low-cost portable ultrasound machines to minimize costs. Two studies explored the issue from the patients' perspective and found that the introduction of tele-ultrasound was associated with lower out-of-pocket costs for the patient due to a reduced need for travel to larger medical centers with formal imaging capacity [15; 20]. In another study, e-learning was found to be more effective than conventional education and superior to self-learning for enhancing novice learners' ultrasound technical skills without increasing their workload [21].
## 2 Materials and Methods
### Equation Finding
#### 2.3.1 Preliminary Considerations
Finally, the mathematical process employed to derive the first- and second-degree equations from ambient temperature, relative humidity, and DPT data involves polynomial regression and least squares methods. Due to limitations in available meteorological data, where direct dew point measurements are often unavailable and data are typically limited to parameters such as temperature and relative humidity, it was necessary to generate a custom dataset. This dataset was created to ensure consistency and cover a broad range of conditions for accurately modeling dew point temperature (DPT). By applying the Magnus-Tetens equation across defined ranges of ambient temperature (T) and relative humidity (RH), this study aimed to establish a comprehensive, reliable foundation for developing predictive models. Specifically, temperature values from 10 \({}^{\circ}\)C to 50 \({}^{\circ}\)C were paired with relative humidity values from 10% to 100%, using a resolution of 100 intervals for each parameter. This structured dataset provided the unique combinations needed to accurately calculate DPT values, addressing limitations and ensuring a consistent basis for model training and evaluation.
# Predicting Topology Propagation Messages in Mobile Ad Hoc Networks: The Value of History
## 5 Evaluation of OLSR-HBP in Mobile Scenarios
### Impact of OLSR-HBP on the Network Performance  
In order to determine impact of the implemented predictor on the network, in this section we analyse the data transfer capability and the energy consumption of the network with and without OLSR-HBP. Next, we explain the evaluation performed and the obtained results.
# Robust and Reconfigurable On-Board Processing for a Hyperspectral Imaging Small Satellite
###### Abstract  
Hyperspectral imaging is a powerful remote sensing technology, but its use in space is limited by the large volume of data it produces, which leads to a downlink bottleneck. Therefore, most payloads to date have been oriented towards demonstrating the scientific usefulness of hyperspectral data sporadically over diverse areas rather than detailed monitoring of spatio-spectral dynamics. The key to overcoming the data bandwidth limitation is to process the data on-board the satellite prior to downlink. In this article, the design, implementation, and in-flight demonstration of the on-board processing pipeline of the HYPSO-1 cube-satellite are presented. The pipeline provides not only flexible image processing but also reliability and resilience, characterized by robust booting and updating procedures. The processing time and compression rate of the simplest pipeline, which includes capturing, binning, and compressing the image, are analyzed in detail. Based on these analyses, the implications of the pipeline performance on HYPSO-1's mission are discussed.  
c 2023, 15, 3756. [[https://doi.org/10.3390/rs15153756](https://doi.org/10.3390/rs15153756)]([https://doi.org/10.3390/rs15153756](https://doi.org/10.3390/rs15153756))  
c 2023 by the authors. Liconse MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/)]([https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/))).  
[[https://doi.org/10.3390/rs15153756](https://doi.org/10.3390/rs15153756) [https://www.mdpi.com/journal/remotesensing](https://www.mdpi.com/journal/remotesensing)]([https://doi.org/10.3390/rs15153756](https://doi.org/10.3390/rs15153756) [https://www.mdpi.com/journal/remotesensing](https://www.mdpi.com/journal/remotesensing))  
c 2023, 15, 3756. [[https://doi.org/10.3390/rs15153756](https://doi.org/10.3390/rs15153756)]([https://doi.org/10.3390/rs15153756](https://doi.org/10.3390/rs15153756))
## 2 Materials and Methods
### Proposal of ITS Architecture for FMCS and Prototype
Finally, it guarantees that only information from registered devices is received, thus guaranteeing the integrity and confidentiality of the information [29]. The proposed architecture has different modules that must communicate through the network, so all communication must be done through the secure hypertext transfer protocol (HTTPS) which assures the information reaches only the intended recipient, and its headers send an authentication value with a key. In the same way, for the transmission of data, the secure file transfer protocol (FTPS) is used, and to guarantee the security of access to information, a hierarchy of users with limited permissions to obtain data is proposed. Once the technologies were selected, the components of the prototype to be developed were defined. The module that was determined suitable for transit vehicles has the following principal components: (1) Heltec WiFi LoRa 32 (v2) device (which has a LoRa SX1276 chip, an OLED 0.96-inch display, and an ESP32 microcontroller unit or MCU); (2) Ublox 6M GPS module, to obtain vehicle location. These two components were integrated, achieving a low-level prototype. The selected LoRaWAN gateway was the Dragino LPS8 and the platform used was The Things Network (TTN).
## 5 Understanding Decentralised Identity Systems
### Architecture  
1. **Decentralised Identifiers**: DIDs are unique identifiers created using cryptographic key-pairs. The public key is published on the blockchain, while the private key remains securely with the user. Documents containing service endpoints and public keys required for interactions are mapped to DIDs (see Figure 7) [52; 53].
2. **Blockchain and Distributed Ledger Technology**: The system utilises DLT to ensure security, immutability, and transparency. To maintain confidentiality, only minimal information like DID documents or attestations is stored on-chain. Personal data remain off-chain, with the blockchain holding links to these data and proofs of transactions [54; 53].
3. **Credential Issuance and Verification**: Trusted issuers provide users with verifiable credentials, which are cryptographically signed and stored in the user's digital wallet. When needed, users present these credentials for identity verification. Moreover, Zero-Knowledge Proofs (ZKPs) enhance privacy by enabling users to prove specific attributes without revealing full credential details [55].
4. **Role of SSI**: Following the principles of SSI, users own and control their identities via digital wallets that hold their DIDs, private keys, and verifiable credentials. This empowers users, ensures transparency, and prevents identity theft prevalent in centralised systems [53; 45].
5. **Agent-Driven Interoperability and Privacy Protection**: Identity agents manage complex interactions for users, making transactions secure and private. Advanced cryptographic methods like ZKPs and selective disclosure allow users to authenticate themselves and disclose specific attributes without exposing actual data [55].
6. **Revocation and Persistence**: The system contains methods that allow issuers to revoke credentials before they expire. Verifiers can instantly check revocations using the blockchain. Persistence is guaranteed through backup methods, enabling users to restore their identities and credentials even if keys are lost [53].
# From the Martian Surface to Its Low Orbit in a Reusable Single-Stage Vehicle--[PERSON]
## 3 Results
### Infrastructure
#### 3.4.1 Mars Base  
With the preliminary design of the Charon vehicle known, an analysis can be made of what requirements the Mars base should fulfil in order for the Charon fleet to operate.  
Base and Launch Pad Location  
The Martian base is to be located in the Deuteronilus Mensae valley due to its scientific interest regarding martian geology, hydrology and climate science, and its abundance of subsurface water resources [41]. While Charon does not need a launch tower to launch, it does need some infrastructure due to the large possible impact of dust particles on the Martian vehicle. Therefore, dust and safety of the Martian habitat are two topics mainly considered for the launchpad. To this end, three launchpads should be built on the side of the central uplift of an impact crater in order to direct flames and debris downwards from a slope [42]. These pads could be constructed from sulfur concrete produced on Mars [43].  
Crew and Cargo Transportation and Discharge  
In order to get the crew and cargo out of the vehicle after landing, the crew will make use of a simple ladder while the cargo is transported out of the vehicle by a crane. The crew and cargo are then transported by a minimum of three transport vehicles each having the capacity for four people and 350 kg of cargo, thus leaving room for members of the launch support crew. The dry vehicle is to be transported by the crane to the maintenance facility.  
The vehicle has to be refurbished in a maintenance facility to protect it from the Martian environment. This facility shall be capable of suspending a rocket to allow for engine disassembly and have all tools necessary for a fast maintenance. Moreover, such facility has to be within an aforementioned crater, to allow for fast transportation to and from the launch/landing pads, while also needing a connection to a source of power. For this reason, the facility is planned to be located in the south-east of the crater, right next to a mountain, while also being close enough to a power plant somewhere between the crater and the base. The facility is planned to be at least 50 meters wide, to contain the vehicle in a horizontal position, while also having enough room to disassemble the engine and perform any work necessary.