esa-sceva/satcom-chunk-collection huggingface dataset:
## 6 Conclusions  
This paper combines the Logarithm Background Subtraction with SAR-SIFT registration technology to form a change detection method suitable for spaceborne SAR platforms. Firstly, the logarithmic transformation technique is introduced to enhance the robustness of the Background Subtraction method. Then, the images are coregistered by SAR-SIFT technology to avoid mismatches-induced detection performance degradation. Next, the static background is modeled by the median filter, and then the subtraction is carried out to help extract the image that contains the changed part. Finally, change detection is performed on the image to obtain the overall change information. The experimental results show that the proposed method can effectively detect the overall change information in spaceborne SAR time-series images, and compared with the traditional pairwise comparison method, the detection efficiency is greatly improved. Future works are focusing on enhancing the algorithm's robustness and performance by introducing all the polarization channels' information.  
Figure 27: Detection result. (**a**) Vehicle distribution map. (**b**) Enlarged image of CFAR detection result.  
**Author Contributions:** [PERSON] and [PERSON] performed the experiments and method. [PERSON] and [PERSON] wrote the manuscript. resources, [PERSON] ([PERSON]) and [PERSON] ([PERSON]); supervision, [PERSON]; project administration, [PERSON]; funding acquisition, [PERSON]; [PERSON], [PERSON] ([PERSON]), [PERSON] ([PERSON]), [PERSON] and [PERSON] gave valuable advice on manuscript writing. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was supported by the National Natural Science Foundation of China under Grant 62201011, 62131001 and the R&D Program of the Beijing Municipal Education Commission grant KM202210009004 and North China University of Technology Research funds 110051360023 XN224-8, 110051360023 XN211.  
**Data Availability Statement:** Data are available on request due to restrictions of privacy.  
**Acknowledgments:** We thank the good advice and comments from anonymous reviewers to help improve the quality of the paper.  
**Conflicts of Interest:** The authors declare no conflict of interest.
## 3 Related Work
### Repetition-Dominated Channel Coding Approaches  
In the repetition-dominated method, the repetition number is first adjusted based on the feedback ACK/NACKs, and then the MCS level is updated. Repetition is the key solution adopted by most NB-IoT designs to achieve enhanced coverage with low complexity. On the other hand, for one complete transmission, the repetition of the transmission is required to be applied to both data transmission and the associated control signaling transmission. Therefore, in most NB-IoT systems, before each NPUSCH transmission, the corresponding control signal data of which includes the Resource Unit (RU) number, the chosen MCS, and repetition numbers are required to be sent via the Narrowband Physical Downlink Control Channel (NPDCCH) [3]. The sequence of transmission with repetition during a single transmission is illustrated as given below.  
Figure 2 illustrates the concept of repeated transmission in NB-IoT where both the NPDCCH and the NPUSCH transmission blocks with the same content highlighted using the same color are repeated four times in the duration of a single transmission. It is also important to highlight that according to the 3 GPP TS 36.211 standard [49], the repetition number for the same block for NB-IoT can only be selected from 1, 2, 4, 8, 16, 32, 64 or 128.  
The selection of a repetition number from the set of \(2^{n}\) with \(n\) from 0 to 7, the process follows a normal network automatic repeat request (ARQ) as defined by the 3 GPP rel. 13 in [5]. On the first successfully decoded uplink packet reception, the BS assesses the perceived radio quality in terms of received signal power. The received power parameter is also used as an input to the scheduler to decide which of the available 8 repetition numbers to use and it is reported back to the NB-IoT node which uses that repetition number till the next time, it experiences a failed transmission. At that moment, another repeat request packet is issued in order to define a new transmission repetition number. It can be noticed that the traditional repetition approach, the repetition number is not only selected from a limited set of numbers and also does not reduce should channel conditions improve. This is one of the drawbacks that the proposed EEACC approach has identified and attempts to mitigate.
## 10 Research Challenges and Future Directions
### Quality and Reliability Concerns  
AI annotation agents, despite their advanced capabilities, often demonstrate limited reliability when tasked with complex, domain-specific, or out-of-distribution inputs [89]. In specialized areas such as medicine or law, these systems frequently misinterpret technical language, leading to annotation errors that human experts would easily recognize. Hallucination adds further complexity, as agents sometimes produce inaccurate labels or generate justifications not supported by the input data. This behavior includes attributing features to images that do not exist or assigning sentiment to neutral text without justification. Such issues highlight the ongoing risk of deploying fully autonomous annotation systems without human supervision in high-stakes contexts.  
Real deployments already show that annotation agents can misfire in varied and costly ways. A study on multilingual classification found that large language models wrongly flagged benign Arabic, French, German, and Hindi posts as hate speech, producing error rates well above human baselines [152]. Follow-up work on HarmonyNet [153] confirmed that even ensemble systems still miss subtle context and let toxic content slip through, while over-blocking neutral messages. Similar accuracy drops were seen when the task moved to low-resource Telugu data [154]. In medicine, ChatGPT added non-existent findings to 60% of its chest-X-ray summaries, risking needless follow-up scans and patient anxiety [155], and another emergency-department trial recorded 2.3% false pneumonia labels on normal images [156]. Researchers showed that a single prompt-injection string can overwrite stored annotations, corrupting entire corpora in one step [157], while a wider survey found that today's security tools catch barely half of such attacks [158]. A study reports that hallucination detection itself is unreliable since current verifiers miss many synthetic facts [159], and that prompt-injection can force an e-commerce annotator into rewriting product tags with marketing slogans, breaking more than fifteen thousand records before rollback [160]. Taken together, these sources show that hallucination, bias, and adversarial control are not theoretical risks but measurable failures that already disrupt annotation pipelines.  
Current research prioritizes reliability improvements through refined prompting strategies that minimize ambiguity, evidence-grounding techniques that require annotations to reference specific elements of the input, and the integration of verifier models that assess label validity [54; 161]. Additional progress is being made in the development of evaluation benchmarks tailored to edge cases, which allow for targeted stress testing and subsequent fine-tuning based on observed failure patterns. As agents achieve higher reliability on narrowly scoped tasks, organizations can introduce selective automation while retaining human oversight for complex or ambiguous annotation decisions.
# Advanced Cooperative Formation Control in Variable-Sweep Wing UAVs via the MADDPG-VSC Algorithm
## 1 Introduction
A novel optimization model for the multi-rigid-body dynamics of the variable-sweep wing UAV is introduced. Through precise model adjustments and dynamic optimization, the method significantly enhances the UAV's sweep angle adjustment and dynamic response capabilities across various flight states, providing robust theoretical support for attitude control during complex flight missions. Unlike simplified linearized models commonly used in UAV control, which overlook mass distribution and inertia variations, the proposed model demonstrates enhanced real-time adaptability, resulting in improved control precision across diverse flight conditions. 2. Development of a cooperative control algorithm for variable-sweep wing UAVs. An enhanced multi-agent deep deterministic policy gradient for the variable-sweep control (MADDPG-VSC) algorithm has been developed, specifically tailored for the cooperative control of multiple variable-sweep wing UAVs. The algorithm employs an adaptive sweep angle control strategy to achieve efficient cooperative control in complex environments, significantly improving trajectory planning and obstacle avoidance capabilities. 3. Construction of an adaptive optimization system for multi-objective reinforcement learning. A multi-objective reward system has been designed to dynamically balance the performance requirements of multi-UAVs in complex tasks. This system ensures global optimization and rapid convergence, effectively avoiding local optima and enhancing the stability and flexibility of task execution. In summary, while existing UAV formation control methods have established a foundation for multi-UAV systems, their limitations in handling continuous action spaces and dynamic environments highlight the need for more advanced solutions. The MADDPG-VSC algorithm introduced in this study addresses these challenges, offering a novel approach to improving the performance of variable-sweep wing UAVs in complex, real-world scenarios. This study not only enhances the current methodologies but also provides a solid framework for future developments in multi-UAV cooperative control. This study is structured as follows: Section 2 analyzes the dynamics of variable-sweep wing UAVs, including longitudinal dynamics and aerodynamic characteristics. Section 3 explores cooperative formation control using multi-agent reinforcement learning (MARL), focusing on the MADDPG-VSC algorithm's design, modeling, and simulation. Section 4 details experimental validation and performance analysis, including platform construction and application results. Finally, Section 5 summarizes the findings and suggests directions for future research.
# Adaptive Damping Log-Domain Message-Passing Algorithm for FTN-OTFS in V2X Communications
## 4 Simulation Results
As shown in Figure 4, the BER performance of the ADL-MP algorithm is compared to that of the conventional LMMSE detection algorithm across different compression factor pairs \((\alpha,\beta)\) over a wide range of SNR values. Yielding results similar to those from the EVA model, the ADL-MP and LMMSE algorithms perform comparably in the low-to-medium-SNR range ([0, 15] dB). However, at higher SNR values ([15, 30] dB), the ADL-MP algorithm demonstrates a clear performance advantage, effectively suppressing noise and interference in the high-mobility LoS channel conditions of the HST scenario. For the case in which \((\alpha,\beta)=(1,1)\), the system corresponds to a traditional OTFS system, and the two detection algorithms exhibit similar performance at low and moderate SNR levels. As \((\alpha,\beta)\) decrease, the ADL-MP algorithm maintains a BER below \(10^{-3}\) even at higher SNR values, meeting the stringent reliability requirements of high-speed V2X communication. Conversely, the BER performance of the LMMSE algorithm deteriorates significantly at higher compression rates, particularly at high SNR values, leading to reduced system reliability. Figure 3: BER performance of the proposed scheme based on ADL-MPA versus LMMSE under different compression factors in the EVA model. Figure 7 presents a comparison of the BER performance between the proposed FTN-OTFS system and conventional OFDM (For fair comparison, the simulation parameters of OFDM were chosen to match those of FTN-OTFS. For example, both systems utilize \(M=64\) and \(N=64\) per frame. This comparison was carried out) under the EVA channel model at a vehicle speed of 120 kmph, utilizing the ADL-MP detection algorithm for both 4 QAM and 16 QAM modulations. As illustrated, with 4 QAM modulation, the FTN-OTFS system achieves an SNR gain of more than 5 dB over OFDM at a BER of \(10^{-3}\). Similarly, under 16 QAM modulation, the proposed system also exhibits significant performance improvements compared to the OFDM system. These simulation results conclusively demonstrate the superior robustness of the proposed FTN-OTFS system in high-mobility V2X communication scenarios. The simulation results demonstrate the robustness of the ADL-MP algorithm, especially in challenging compression scenarios and at high SNR levels. These findings emphasize the critical role of optimized detection in ensuring the reliability and efficiency of communication systems in dynamic vehicular environments. Figure 6: BER performance of the proposed scheme based on ADL-MPA versus MRC with different compression factors in the HST scenario. Figure 7: BER performance comparison between FTN-OTFS and OFDM under the EVA channel model. (**a**) 4 QAM, (**b**) 16 QAM.
## 4 Results
### REE Concentrations in the Roots of Scutellaria bicalensis  
The concentrations of REEs and several parameters on the REE distribution characteristics for roots of _Scutellaria bicalensis_ in various habitats are listed in Table 3. The median was also utilized to represent the statistical characteristic of REE concentrations in the roots of various habitats. Roots of _Scutellaria bicalensis_ contained similar \(\Sigma\)REE and \(\Sigma\)LREE in NGH (\(\Sigma\)REE = 2.02 mg\(\cdot\)kg\({}^{-1}\), \(\Sigma\)LREE = 1.78 mg\(\cdot\)kg\({}^{-1}\)) and BCHs (\(\Sigma\)REE = 2.04 mg\(\cdot\)kg\({}^{-1}\), \(\Sigma\)LREE = 1.82 mg\(\cdot\)kg\({}^{-1}\)), which are higher than that in APHs (\(\Sigma\)REE = 1.78 mg\(\cdot\)kg\({}^{-1}\), \(\Sigma\)LREE = 1.60 mg\(\cdot\)kg\({}^{-1}\)). However, roots in NGHs contained the highest HREE concentrations, with the median \(\Sigma\)HREE being 0.212 mg\(\cdot\)kg\({}^{-1}\), and roots in BCHs contained the lowest HREE concentrations, with the median \(\Sigma\)HREE being 0.183 mg\(\cdot\)kg\({}^{-1}\), which was exactly opposite to the \(\Sigma\)HREE in the soils. LREE/HREE and La\({}_{N}\)/Yb\({}_{N}\) decreased following the order of BCHs \(>\) APHs \(>\) NGHs, which was inconsistent with the order in the soils. The considerable variance in REEs adsorption by roots from the rhizosphere soil between various habitats can be speculated. The concentrations of REEs with even atomic numbers were higher than those with odd atomic numbers at HREEs, which conformed to the rule of Oddo-Harkins [24; 25]. In general, the chondrite-normalized REE patterns presented an obvious right-inclined style with the enrichment of LREEs (Figure 3b,d,f). Positive Eu anomalies were observed for some samples in all habitats, indicating the adsorption of Eu from soil to some extent. However, the negative Ce anomaly of roots was stronger than that of soil, especially in NGHs, since Ce\({}^{4+}\) was hard to be adsorbed by roots.
## 2 Materials and Methods
### Field Monitoring  
Saemangeum in Korea is a large-scale reclaimed land with 291 km\({}^{2}\) of land and 118 km\({}^{2}\) of lakes, possessing broad and flat terrain with almost no obstacles such as mountains or hills nearby [19]. The soil of Saemangeum is saline, making plant growth challenging and resulting in low vegetation coverage. Due to its proximity to the coast and the absence of obstacles, a substantial amount of fugitive dust can originate from the soil. By cultivating halophytes, the emission of fine dust was suppressed in the initial stages of reclamation [10; 13; 18; 32].  
Field monitoring was conducted to understand the averaged wind speed and the particle size distribution characteristics of the fine dust in the agricultural life experiment complex (35.828466 N, 126.687389 E) in Saemangeum, a 20-ha site in the center of the reclaimed land. The experimental area, almost devoid of surrounding obstacles, provided  
Figure 1: Research flow chart for calculating the PM reduction using crop cultivation in agricultural field.  
suitable environmental conditions to test the dust reduction effects due to crop cultivation. Barley and trtictale were each cultivated on 2000 m\({}^{2}\), and field monitoring was performed to analyze the wind environmental characteristics of the farmland and to collect crops needed for the experiment (Figure 2). To apply wind speeds as the boundary condition in the wind tunnel experiment, they were measured at different heights from the ground surface using a multi-channel anemometer (Kamnomax anemomaster 1560, Kanomax Inc., Osaka, Japan). Upon measuring the wind speed during daytime at the experimental reclaimed land, the average wind speeds at heights of 25, 50, 100, and 150 cm from the ground were found to be 1.87, 2.45, 3.10, and 3.75 m/s, respectively, with a maximum wind speed of 5.5 m/s being observed at 150 cm height. Considering the height of the crops, the wind tunnel experiments were conducted using the 3.10 m/s wind speed measured at 100 cm as the representative wind speed. During the experimental period, the on-site weather conditions were measured by installing an automatic weather station (AWS, U30, Onset Inc., Bourne, MA, USA), and the annual weather information was obtained using data from the nearest official meteorological station. For the wind tunnel experiment, barley and trtictale crops that had grown more than 1 m were sampled.
## 1 Introduction
### Definition of iMMS  
A new definition for iMMS is noted in this section. The term personalization is considered a synonym for individualization. [PERSON] et al. [18] define mass individualization as follows: \"In the mass-individualization paradigm the customers are involved in the design process! This is a new challenge of this paradigm. In mass-customization even if some customers feel as if they are designing their product, the truth is that they are NOT involved in the design of their products. They are simply selecting an option.\" With this definition, it becomes clear that individualization focuses on customer-related development activities in order to create a higher added value for customers. In addition, the distinction from mass production becomes clear by this definition.  
In this paper, the term MMS is used as defined by [PERSON] et al. Accordingly, MMS are very small components that, in the best case, combine sensors, electronic processing of data and physical action (actuators) [19]. Consequently, an iMMS can be defined as follows: An iMMS is an MMS that consists of a limited number of components. At least one of them is unique in terms of geometric shape and/or electrical or mechanical function.
# Numerical and Experimental Analysis of Torsion Springs Using NURBS Curves
## 1 Introduction  
Torsion springs transfer power through the twisting of their coil, and provide advantages such as module simplification, efficient use of space, and reduction of overall product weight. As such, they have been widely used in various electronic products and industrial fields, including automobiles and machinery.  
Research on these springs began in 1963 with [PERSON]'s study on isotropic spiral compression and tension, and torsion springs [1; 2]. Thus far, the spring design formula proposed by [PERSON] is used as a standard and has been extensively employed in industrial-machinery applications. This applied design formula can easily calculate the rotation angle of the spring for the applied load. However, as this formula simplifies the problem, it is difficult to determine the behavior or deformation of a torsion spring according to the change in load conditions with different angles and directions.  
Case studies considering the structural analysis of such springs using finite-element analysis (FEA) have been proposed to solve this design problem [3; 4; 5; 6]. This method allows the designer to visually confirm and design these springs considering the stress and displacement that locally occur in the spring.  
As FEA expresses curves as a sum of subdivided linear elements, many elements are needed to increase the reliability of curve-structure analysis. As springs are curved structures, the number of elements used in these analyses must inevitably be increased to ensure accuracy, thereby lengthening analysis time. Due to this increase in spring-design time, as well as the aforementioned design problem,and considering the effective product applications of these springs, a more effective torsion-spring design method is required.  
This study proposes the evaluation method of deformation behavior of torsion spring via FEA using nonuniform-rational-basis-spline (NURBS) curves [7; 8]. The NURBS curve is a model that can accurately express a curved structure with a small amount of information and a simple calculation formula. These curves were applied to FEA, and through experimentation, the angle and displacement values for the actual spring load were converted into useable data. The torsion-spring displacement values measured through experiments were converted into coordinates that could be expressed using NURBS curves. Experiments were then conducted for comparison with the FEA results and to verify the validity of this method.