esa-sceva/satcom-chunk-collection huggingface dataset:
# Remote Sensing Image Enhancement Based on Non-Local Means Filter in NSCT Domain
## 4 Results and Discussions
### Subjective Analysis  
Figure 5 is the enhanced result of the five image enhancement techniques simulated on Image 1. The size of the original image is 556 \(\times\) 556. Figure 5a is the original image; Figure 5b is the result enhanced using the HE method, and it displays the over-enhancement phenomenon; Figure 5c depicts the enhancement result obtained by the ESIHE algorithm; Figure 5d presents the result achieved by the FLM approach, and has relatively poor visual effects; Figure 5e represents the enhanced result obtained using the LSCN technique; Figure 5f is the result achieved by the proposed approach. From the enhanced images, we can see that the proposed method has better image enhancement effects in terms of detail and edge preserving.  
Figure 6 is the result of the five approaches simulated on Image 2. The size of the original remote sensing image is 548 \(\times\) 548. Figure 6a depicts the original image; Figure 6b is the image enhanced using the HE technique, and also displays the over-enhancement phenomenon in some regions; Figure 6c is the enhanced result obtained by the ESIHE method; Figure 6d is the result achieved by FLM; the result obtained by LSCN is shown in Figure 6e; the enhanced result achieved by the proposed algorithm is shown in Figure 6f. From the enhancement results, we can see that the proposed method has achieved the goal of noise suppression and image details preserving.  
Figure 5: Comparisons on Image 1. (**a**) Original image; (**b**) Histogram equalization (HE); (**c**) Exposure based sub-image histogram equalization (ESIHE); (**d**) Feature-linking model (FLM); (**e**) Linking synaptic computation (LSCN); (**f**) Proposed method.  
Figure 7 is the enhanced result of the five image enhancement methods simulated on Image 3. The size of the original image is 256 \(\times\) 256. Figure 7a is the original remote sensing image; Figure 7b,c are the enhanced results achieved by the HE and ESIHE approaches, respectively; the enhancement result obtained using the FLM approach is shown in Figure 7d, with an image transformation that is too light and severely distorted; Figure 7e depicts the result enhanced by the LSCN algorithm, which has achieved enhanced effects to some extent; Figure 7f presents the enhancement result obtained by the proposed method. From the results, we notice that the proposed approach has better performance due to the fact that it makes the enhanced image have moderate brightness, rich detail, and clear edges.  
Figure 6: Comparisons on Image 2. (**a**) Original image; (**b**) HE; (**c**) ESIHE; (**d**) FLM; (**e**) LSCN; (**f**) Proposed method.  
Figure 7: \(Cont.\)
## 2 Experimental System
### Monitoring System Error and Sensitivity Calibration  
The microseismic monitoring network was calculated according to the three-dimensional spatial arrangement scheme of the microseismic monitoring points, and the positioning error and sensitivity of the 3720 m bottom structure microseismic monitoring system were analyzed, as shown in Figure 5. The analysis of the network showed that the microseismic monitoring system had a positioning error in the first mining area within 10 m, and the microseismic events with a minimum of \(-\)2.7 magnitude were monitored with guaranteed accuracy, which met the requirements for monitoring the stability of the substructure.
# Routing Protocols for Mobile Internet of Things (IoT): A Survey on Challenges and Solutions
## 4 Solutions to the Issues Faced by RPL during Mobility
### RSSI Based Solutions
#### 4.3.1 Mobility and Energy-Aware Routing Protocol (ME-RPL)  
Authors [42] proposed Mobility and Energy-Aware RPL (ME-RPL), which considers ETX, Battery Depletion Index (BDI), and routing metrics RSSI. For the route selection, the participant nodes choose the parent from the DODAG only when it is within the RSSI range. Calculation from link metric (ETX) and node metric (BDI) selects Preferred Parent based on the _rank_. ME-RPL follows the additive property and considers the minimal value of root cost, adapts the ContikiMAC/6 LowPAN MAC protocol; simulations are done in Contiki-207. Node CC2420 is considered and the RSSI value range is from \(-50\) dBm (100% quality) to \(-100\) dBm (0% quality). Simulation duration is 24 h, radio environment is UDGM while the data packet timer is set to 60 s. It is observed that the composite routing metric used in ME-RPL proposed protocol improves the packet delivery ratio to 92% and energy consumption to 1.2 MJ/min as compared to basic RPL with a packet delivery ratio of 42% and energy consumption of 2.8 MJ/min for health care applications. For animal tracking applications ME-RPL provided a packet delivery ratio of 80% as compared to 35% provided by RPL. In addition, the authors observe that the energy consumption in ME-RPL is reduced to 1.1 MJ/min as compared to basic RPL, consuming more energy of 2.8 MJ/min for animal tracking applications.
## 3 Generation of All-Weather LST:  
Due to its high spatial resolution and retrieval accuracy, TIR LST is often used for generating all-weather LST. FY-3C LST is one of the most commonly used TIR LST datasets in China. Therefore, this study uses the FY-3C Level 3 LST product, VIRR LST, as the base data for generating all-weather LST. To generate all-weather LST, we fill the cloudy pixels in VIRR LST with RFRR-LST values generated by the RFRR model. Specifically, each cloudy pixel in VIRR LST is identified and subsequently replaced with the corresponding RFRR-LST value, thereby generating an all-weather LST derived from a VIRR LST. This newly generated all-weather LST is denoted as FMLST (Fusion Microwave Land Surface Temperature).
# Research on Defect Detection of Bare Film in Landfills Based on a Temperature Spectrum Model
## 1 Introduction
Based on improved guided image filtering and edge detection image processing to solve the problem of measuring the internal defect size of the HDPE film weld seam, a completely different method was used to locate the defect area in the infrared image of the HDPE film.
# Sentinel-2 Reveals Record-Breaking Po River Shrinking Due to Severe Drought in 2022
## 2 Materials and Methods
### Remote Sensing Data Processing
The boundary area potentially subjected to a 200 yr return period flood is referred to as \"Fascia A\" and represents an administrative layer for the Po Basin Authority (data available at [[https://webgis.adbpo.it/catalogue/#/map/1664](https://webgis.adbpo.it/catalogue/#/map/1664)]([https://webgis.adbpo.it/catalogue/#/map/1664](https://webgis.adbpo.it/catalogue/#/map/1664)) (accessed on 24 July 2024). Within this area, the spatial domain of the analysis was determined based on OWF for the complete time series (2016-2023). Pixels with an OWF higher than or equal to 5% were considered as belonging to the riverbed under normal conditions. The 5% mask was then polygonized, and holes were filled in a GIS environment. The resulting polygon was cut into 1 km long slices, and for each slice the mean of all OWF pixel values was calculated, resulting in a time series of spatially averaged OWF for each slice. The coefficient of variation of the OWF (CVOWF) was calculated as:  
\[CV_{OWF}=\sigma^{2}{}_{OWF}/\mu_{OWF} \tag{4}\]  
where \(\sigma^{2}{}_{OWF}\) is the variance of overall water frequency and \(\mu_{OWF}\) is the average of overall water frequency. To reduce the noise of CVOWF data, the analysis was performed on a 10 km moving average along the distance from the river mouth. Figure 2 presents a summary of the main phases of the pre- and post-processing of satellite data applied to monitor river shrinking. Two focus areas along the Po River were selected for presenting the key results of this study based on the following: the intensity of the anomalies (MWFAs) observed (as high-intensity anomalies facilitate a more comprehensive understanding of the variation and impact of the drought within the regions); the absence of artifacts, such as cloudiness (essential for obtaining accurate and unobstructed observations, which in turn ensures data quality and integrity); and, the existence of extensive riverbeds and breaching areas (crucial for comprehending the dynamics of river flow and the interconnectivity of diverse hydrological systems). Figure 2: Data processing flowchart showing the main steps followed to analyze Sentinel-2 MSI data for detecting anomalies in water frequency.
## 1 Introduction
[13] reported the results of a study of structural characteristics, as well as the possibility of using Li\({}_{0.15}\)Sr\({}_{0.85}\)TiO\({}_{3}\) ceramics as anode materials for lithium-ion batteries. Some cases also show the importance of thin films for use against incident radiation. [PERSON] et al. [14] presented that magnetic properties and shielding characteristics were investigated as well as function of thickness and number of layers. Difference in magnetic properties for Ni\({}_{80}\)Fe\({}_{20}\) films with different thickness is due to formation of defect layers on the top and bottom film surfaces during electrodeposition processes. They also studied the effect of hydrostatic pressure (up to 1.1 GPa) in wide temperature range of magnetic properties optimal doped La\({}_{0.70}\)Sr\({}_{0.30}\)MnO\({}_{2.85}\) magnetic with oxygen vacancies [15]. In 2020, [PERSON] et al. [16] devoted to assess the prospects of using CuBi\({}_{2}\)O\({}_{4}\) composite films of various thicknesses as protective coatings against exposure to ionizing radiation. Owing to the advantages of nanomaterials, oxides with a spinel structure of the general formula AB\({}_{2}\)O\({}_{4}\) are known as possible active materials for the energy storage device [17]. [PERSON] et al. [18] reported morphology controlled the fabrication of AlV\({}_{3}\)O\({}_{9}\) (AV) by surfactant-assisted hydrothermal method and the use of AV products were demonstrated as both positive and negative electrode in Li-ion batteries. They also investigated the effect of AlV\({}_{3}\)O\({}_{9}\) as cathode materials in Li-ion batteries on the zero to two dimensional carbon nanostructures [19]. Based on the above literature discussion and research topics, these cases demonstrate that film thickness uniformity plays an important role in the effect of film properties. In general, optical coating technology requires thickness control in the range of \(\pm\)1% to achieve reproducible performance. In this study, a novel flux mapping method based on 50 million ray tracing under electron beam evaporation is proposed for optical thin film deposition, and its intensity distribution is equivalent to film thickness accumulation
###### Abstract  
Long-term displacement often occurs in lava fields at volcanoes after flow emplacements. The investigation and interpretation of displacement in lava fields is one of the key factors for the assessment of volcanic hazards. As a typical Hawaiian volcano, Piton de la Fournaise volcano's (La Reunion Island, France) main eruptive production is lava. Characteristics of the lava flows at Piton de la Fournaise, including the geometric parameters, location, and elevation, have been investigated by previous studies. However, no analysis focusing on the long-term post-emplacement displacement in its lava fields at a large spatial extent has yet been performed. One of the previous studies revealed that the post-emplacement lava subsidence played a role in the observed Eastern Flank motion by conducting a preliminary investigation. In this paper, an InSAR time series analysis is performed to characterize the long-term displacement in lava fields emplaced between 1998 and 2007 at Piton de la Fournaise, and to conduct an in-depth investigation over the influence of post-emplacement lava subsidence processes on the instability of the Eastern Flank. Results reveal an important regional difference in the subsidence behavior between the lava fields inside and outside of the Eastern Flank Area (EFA), which confirms that, in addition to the post-lava emplacement processes, other processes must have played a role in the observed subsidence in the EFA. The contribution of other processes is estimated to be up to \(\sim\)78%. The spatial variation of the observed displacement in the EFA suggests that a set of active structures (like normal faults) could control a slip along a pre-existing structural discontinuity beneath the volcano flank. This study provides essential insights for the interpretation of the Eastern Flank motion of Piton de la Fournaise.  
lava flow subsidence; InSAR time series; Piton de la Fournaise; volcano flank motion 1
# Study on Load Distribution and Fatigue Elastic Life of Ball Screw under Ultimate Conditions
## 4 Conclusions  
This paper calculates the load distribution of ball screws considering the nut position and the screw length. Based on the distribution of loads, the raceway plastic deformation is studied by [PERSON]'s elastoplastic theory. Finally, based on the concepts of plastic deformation and fatigue elastic life, the fatigue elastic life of the ball screw under the ultimate conditions is studied, and the influence of each parameter on the fatigue elastic life is studied. The following conclusions are drawn:  
Under a static load, the ball screw's load distribution surface remains relatively consistent despite increasing loads. The ball bearing the maximum force and the nut's position do not change. Longer screws lead to higher maximum ball loads and increased force unevenness. The ball force is most uniform when the nut is in the middle, becoming uneven near the ends. Additionally, the plastic deformation of the screw raceway varies with the nut position and ball number.  
The error between theoretical and experimental fatigue elastic life values in this study is less than 8%, validating the method. As screw length and load increase, ball screw fatigue elastic life decreases. Having nut positions closer to the screw ends also reduces fatigue elastic life. When the fatigue elastic life is at its maximum, the ratio of the nut position to the screw length is around 0.7 and is not affected by the screw length, load, and type. Operating the nut in this position is recommended.  
With the increase of contact angle and ball diameter, the fatigue elastic life of the ball screw increases. With the increase in conformity ratio, the fatigue elastic life of the ball screw decreases. In addition, the ball diameter has a great influence on the fatigue elastic life; and when the conformity ratio is low, its influence on the fatigue elastic life is very obvious.  
Conceptualization, L.L. and C.L.; methodology, L.L.; validation, L.L. and W.W.; writing--original draft preparation, L.L.; writing--review and editing, S.C. and C.L.; supervision, S.C. and C.L. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
Data Availability Statement: Data are contained within the article.  
This work was supported by the Key Laboratory of High-efficiency and Clean Mechanical Manufacture at Shandong University, the Ministry of Education, and the National Demonstration Center for Experimental Mechanical Engineering Education at Shandong University.  
The authors declare no conflicts of interest.  
Figure 11: The influence of different parameters on fatigue elastic life.
## 4 Study Case
### Data Analysis: Iteration 1
#### 4.4.1 Loop 1  
Loop 1 focuses on the fundamental findings in each paper through the constant comparison of data and abstractions. Figure 6 shows the progress of the **keywording**, **mapping**, and **synthesis** steps, each of which includes **open**, **selective**, and **theoretical coding** stages.  
Open coding focuses on general _concepts_, while **selective coding** evolves from general concepts to specific _categories_. Finally, **theoretical coding** deepens the categories on theoretical _propositions_.  
Table 7 expands on the data and examples shown in Figure 6. In the keywording section of Table 7 are shown examples of the codes per article, illustrating the evolution from **keywording open coding to selective coding**. The Keywording theoretical coding concludes that the findings found in each article can be expressed through two essential propositions, which can be synthesized as {**A GT of...** } and {**Use GT to...** }.  
Figure 5: Activity diagram for iteration 1.  
**{A GT of...}** presents a theory about the study, while **[Use GT to...}** uses GT to study the subject in depth. In the **mapping phase**, the sub-phase open coding unified **[A GT of...}** and **[Use GT to...}** conceptually. Selective coding deepened the analysis and unified the two codes. Theoretical coding led to the proposition that 98% of articles were categorized. Finally, **synthesis** emphasized the need to clearly express the [Emerging theory] in these two ways. See Figure 6 and Table 7 for more details on the keywording, mapping, and synthesis steps and their concepts, categories, and propositions.
## 1 Introduction  
### Key Topics  
Precision agriculture (PA) [1] is a very significant societal challenge and promises to enable several significant improvements: increase of productivity; optimal, and thus reduced, use of pesticides and fertilizers; and decreased use of water. These will translate into substantial benefits, including making more food available for mankind, increasing environmental sustainability, and contributing to the mitigation of climate change effects [2]. One key component of precision agriculture is crop health diagnostic capability. Within this context, in the last 5 years the use of lightweight unmanned aerial vehicles (UAVs) equipped with multispectral sensors has become quite popular. UAV-based surveys offer unprecedented ground resolution and operational capability. The second feature is particularly significant when periodic monitoring has to be performed, as the operator is free to choose the optimal time to fly.
## 3 Proposed Methods  
As it is challenging to effectively identify spoofing in terms of signal strength, angle estimation based on the antenna array can barely achieve effective direction finding for spoofing. Considering the DOA stability of spoofing, we apply the system and signal processing model discussed in Section 2 to determine the inter-station single-difference directions of all the GNSS signals received by the dual-antenna GNSS/MIMU system so as to obtain the DOA angles of the single sources for each epoch. We propose a mobile dual-antenna GNSS/MIMU-based method for direction finding of signal sources. The proposed method first utilises the inter-station single-difference carrier-phase measurements after integer ambiguity compensation to distinguish real GNSS signals from spoofed signals to confirm and extract false and spoofed satellite signals. Subsequently, we select the most favourable computational coordinate system based on multiple simplified assumptions. Finally, based on multi-epoch DOA angle measurements of spoofing signal sources, we establish a multi-epoch least squares observation equation and an EKF filtering model to determine high-precision directions of spoofing signal sources. The proposed method is described in this section.
# Audio Steganalysis Estimation with the Goertzel Algorithm
## 4 Statistical Coefficient Results
### Audio Quality Metrics Comparative Results
#### 4.2.1 Estimates in the Time Domain  
The following estimates are made in the time domain [8]:  
Signal noise to ratio (SNR): This represents the relationship between the amount of power of the host audio vector and the power of the audio vector of the supposed stegoaudio [29].  
Segmental signal-to-noise ratio (SNRseg): This represents the relationship between the amount of power of the host audio vector and the power of the audio vector of the supposed stegoaudio in segment lengths between 15 ms and 20 ms [29; 30].  
Czenakowski Distance (CZD): Also called the percentage of similarity. This is a correlation-based metric used to directly compare the time domain sample vectors [8].
# Managing Access to Confidential Documents: A Case Study of an Email Security Tool
## 5 Results
### Sharing Confidential Information
#### 5.3.3 Scenario 3: Medical Health Form with a Doctor's Office  
For the third scenario, we first asked the participants to review the medical history form, state whether they considered it to include sensitive information, and rate this form's information sensitivity. All participants stated that this form included sensitive information (e.g., medical history, health habits, and SSNs). We found that 78.9% of the participants rated this form's information sensitivity as \"very sensitive\".  
After providing the hypothetical scenario, the participants were asked to email this form to a doctor's office. The participants rated their comfort with sharing their SSNs in the medical history form with the doctor's office using their regular or standard email and secured email. Also, they were asked to rate their concerns about sharing their SSNs in the medical history form with the doctor's office using their regular or standard email and secured email.  
We performed the Wilcoxon signed-ranks test, which indicated that the participants' comfort with sharing SSNs in the medical history form via secured email was rated higher compared with sharing it via standard email (Z = -3.8, \(p\) < 0.001 (Table 5)). All participants rated their satisfaction as moderately or very satisfied if they shared their SSNs with the doctor's office using secure email compared with standard email. Also, the test indicated that the users were more concerned if they shared their SSNs with the doctor's office via regular or standard email than secured email (Z = -3.9, \(p\) < 0.001 (Table 5)). We found that 73.7% of the participants were \"not at all concerned\" if they shared their SSNs with the doctor's office using secure email compared with standard email (52.6% said they were \"very concerned\").  
The participants were comfortable with sharing their confidential information via an encrypted email. Our results showed that the participants were more satisfied when they shared their medical, tax, and employee information forms via secure email compared with their regular email. However, they expressed that they would be more concerned if they shared these confidential forms via regular email instead of an encrypted email.