esa-sceva/satcom-chunk-collection huggingface dataset:
# Investigation of Energy Cost of Data Compression Algorithms in WSN for IoT Applications
## 2 Related Work
Launch vehicle data is compressed using a modified version of the Rice compression method [32], resulting in a 2:1 compression ratio. A high compression ratio can be achieved by combining different data compression techniques [33]. It is also critical to implement data compression correctly in hardware in order to improve compression performance [34; 35]. To balance hardware costs with a feasible compression ratio, [PERSON] et al. [36] proposed a modularized strategy. Using a two-stage hardware design, [PERSON] et al. [37] predicted an increase in compression and decompression rates. However, in most cases, the objective of deploying a WSN is to monitor a specific occurrence that is of interest. An algorithmic approach that employs both Run Length Encoding (RLE) and basic Huffman encoding to produce compression ratios that outperform current state-of-the art techniques has been suggested in this study. Large-scale wireless sensor networks (WSNs) that can be used in everyday life head one of the biggest challenges in making mechanisms that allow the network to run for long periods of time despite the fact that wireless sensor nodes can only store or gather a limited amount of energy [38]. Since sensor node data transmission is a major drain on the network's energy reserves, approaches to limit the quantity of data sent between nodes are of particular importance. Compressing data locally before transmitting it is the primary goal of this study to minimise network traffic. Though the field of data compression has been around for a long time, most existing techniques can't be simply translated to wireless sensor nodes because of the restricted hardware resources, notably programme and data memory [39]. Even though current wireless sensor nodes might run many of the time-consuming compression techniques, this would leave the nodes with limited resources for other functions such as sensing and communication. Using a compression approach meant that these nodes would be less likely to go into deep sleep, which is essential for maximising energy efficiency. WSN-specific data compression algorithms have been presented recently. High compression ratios can be achieved by using algorithms that are computationally cheap, however many of these approaches rely on correlation of data collected by sensor nodes.
## 4 Results
### Early Warning System
#### 4.3.2 Software Function  
The software uses web-based GIS tools with open source programming language Python, PHP (Personal Home Page) and a PostgreSQL/PostGIS database that is built into the server and integrated into the website, so that the administrators can manage the system via the internet. There are three functional software modules as follows: (1) the system administration component that controls the operation of the stations and the system user information through the internet; (2) the environmental information-processing component, displaying the temperature, wind direction, and humidity, and the information-processing operations for the administrators. In the event of a forest fire, after checking the actual information from the image of the monitoring station, the software allows the processing and transmission of the fire information; and (3) the spatial mapping component, which integrates the information on forest distribution according to fire risk. This has a summarizing function and allows for the managers to look up information on fires. In addition to information on fires reported via email and SMS, the software also incorporates a map of fire points that allows users to make direct visual observations remotely (Figure 11).  
Figure 10: Model of the forest fire early warning system.
# Innovative Approaches to Semi-Transparent Perovskite Solar Cells
## 3 Transparent Electrodes for ST-PSCs
Furthermore, the conductivity of transparent carbon grids is improved by inserting a thin layer of multi-walled CNTs, resulting in an 8.21% PCE and 24% AVT. Recently, [PERSON] et al. doped MoO\({}_{x}\) on a CNT, enhancing its energy-level alignment and hole-transfer rate. Furthermore, the optimized thickness of the MoO\({}_{3}\) (8 nm)-CNT electrode exhibited 70% transparency at 550 nm, obtaining a PCE of 17.3% [104]. The conductive polymer PEDOT:PSS is well known as a hole-transporting layer for organic solar cells and PSCs [105; 106; 107; 108]. PEDOT:PSS has high potential as a transparent electrode, owing to its minimal sheet resistance and better optical transparency. However, there is a big hurdle to use PEDOT:PSS as a transparent electrode for ST-PSCs. The PEDOT:PSS is dispersed in water, and if it is coated on perovskite directly, the perovskite layer collapses very quickly from the water. To address this problem, [PERSON] et al. developed a method called the transfer lamination technique. In this method, PEDOT:PSS films are placed on a transfer medium (such as polydimethylsiloxane) initially and are later shifted to perovskite layers to laminate them [109]. They demonstrated that a ST-PSC with FTO/c-TiO\({}_{2}\)/m-TiO\({}_{2}\)/CH\({}_{3}\)NH\({}_{3}\)PbI\({}_{3}\)/Spiro-OMeTAD/PEDOT:PSS configuration shows a 10.1% PCE with a 7.3% AVT after careful modifications of thickness and other parameters (Figure 4c and the inset of Figure 4c). Furthermore, this technique was modified by [PERSON] et al., and they fabricated TCO-free ST-PSCs by employing PEDOT:PSS as both the top and bottom electrodes [110]. They fabricated low-temperature and fully solution-processable TCO-free ST-PSCs for tandem and flexible applications. The electrically conductive layers were fabricated via an easy and quick casting or printing method, and the TCO on the top and bottom was replaced by nitric-acid-annealed PEDOT:PSS. The champion device demonstrated an efficiency of 13.9% for ST-PSCs, and the flexible PET and PI devices showed a PCE of 10.3 and 7.3%, respectively, with good mechanical stability. After 1000 bending cycles, the ST-PSC retained >90% of its initial PCE, demonstrating exceptional mechanical robustness. To add to this modification, [PERSON] et al. reported that doping a fluorosulfactant can boost the PCE and AVT by improving the phase separation of the polymer network of PEDOT:PSS [111]. As summarized in Figure 4d, the highest efficiency was achieved in ST-PSCs with TCO. However, the efficiency and transmittance were still low, and efforts to improve them are necessary. On the other hand, although the efficiency was still low, carbon-based electrodes can be a favorable strategy for realizing ST-PSCs with more robustness and high AVT. In addition, in order to overcome the trade-off characteristics of conductivity and transmittance, efforts to improve optical and structural aspects should be continued.
## 3 Experimental Results
### Increased Proton Energies
As in Figure 5a, we distinguish between the maximum and mean values obtained for a given target thickness. The dependence of both quantities on target thickness is similar to that observed for the proton energies, i.e., adding the DPM leads, for the best cases, to an increase in the maximum (resp. mean) conversion efficiency by 56% (resp. 75%), i.e., from 1.6% to 2.5% (from 0.8% to 1.4%). The conversion efficiencies recorded here for TNSA protons are on par, i.e., in the few percent range, with what has been measured in other ion acceleration regimes, e.g., RPA [51; 52]. Interestingly, for the DPM shots, the observed drop in proton cutoff energy and conversion efficiency with decreasing target thickness below \(d=250\,\text{nm}\) is gentler than in previous studies using longer laser pulses. Specifically, the decrease is \(\sim\)0.54 for the cutoff energy (from 30 MeV to 15 MeV) and \(\sim\)0.47 for the conversion efficiency (from 1.4% to 0.8%) as the target thickness is reduced from \(d=250\,\text{nm}\) to \(d=20\,\text{nm}\). These values are comparable to those reported in Ref. [40] with a 35 fs pulse (0.31 for cutoff energy and 0.59 for efficiency, for thicknesses from 20 to 100 nm) but significantly lower than those obtained with a 900 fs pulse in Ref. [42] (0.67 for cutoff energy and 0.79 for efficiency, for thicknesses from 10 to 100 nm). The smaller decrease obtained in our case with ultrahigh-contrast, ultrashort pulses indicates a more robust acceleration scheme, because even ultrathin targets (down to \(d=20\,\text{nm}\) here) do not have time to fully expand before the laser intensity peaks, resulting in a sustained \"plateau\" in the performance metrics. A similar plateau behavior in proton acceleration has been reported in Refs. [38; 43]. To summarize this section, our main finding is that, despite reducing the on-target laser energy by almost a factor of 2, the use of a double plasma mirror (DPM) leads to a significantly (by \(\sim\)40%) higher proton cutoff energy, but is accompanied by a loss of low-energy protons (see Figure 4a). It is also worth noting that, in the same experiment, very similar neutron yields from \((p,n)\) nuclear reactions were detected in both direct and DPM shots [11]. As will be detailed below, the enhanced ion acceleration in high-contrast laser-foil interactions originates from a close overlap of the peak accelerating electric field with the proton bunch. A similar interpretation was put forward to explain the strong increase in the conversion efficiency observed when relatively thick (\(d=5\,\text{\mu m}\)) targets were irradiated by two sequential ps-long laser pulses [53].
# Mechanical Performance Characterization of Lignin-Modified Asphal Mixture
## 1 Introduction  
Asphalt pavement is the most widely utilized pavement type in the world thanks to its various advantages [1]. Every year, a huge amount of asphalt binders are consumed to pave roads. It is known that asphalt is a hydrocarbon residue from the crude-oil refining process, which is nonrenewable. However, the advances in oil refinery technology have degraded both quantity and quality of asphalt, thus leading to increased costs of asphalt and needs for asphalt modification. The rising cost and environmental concerns have driven engineers to seek renewable, sustainable materials to substitute for the petroleum-based binder products or to improve the binder performance through modification [2]. Bio-based waste has got much attention in the asphalt industry due to the improvement in binder properties and environmental sustainability by shifting from fossil-based resources to bio-based resources. Bio-based resources are in favor from the sustainability point of view: They are renewable and do not contribute to climate change, as greenhouse gases are captured from the atmosphere as a result of photosynthesis in the original vegetal source [3].  
In recent years, lignin products have gained a lot of attention as a partial replacement or a performance modifier for asphalt. Lignin is a cross-linked phenolic polymer. The composition of lignin varies from case to case. Normally, it is composed of benzene rings with a randomly attached hydroxyl group. [4]. Lignin is the second most abundant organic polymer on our planet. It also exists in the by-products of biofuel production and the paper making industry [5]. With regards to thelarge amount of lignin products, it will bring huge benefits to find alternative applications of lignin to further maximize the economic potential of biofuel or paper industry. Lignin is a renewable source for aromatic compounds, which has a good compatibility with asphalt. It can reinforce asphalt binder due to the cross-linked structure. It was reported to increase the rutting resistance of asphalt binder at high temperatures. However, negative effects of lignin on fatigue and thermal cracking resistance of asphalt binders have also been reported. Besides, lignin has been proven to have a high potential of anti-oxidation due to the polyphenic structure and free radical scavenging activity. Efforts have been put to investigate its potential as an antioxidant in the asphalt binder [6; 7].  
The above studies have demonstrated the feasibility of using lignin in asphalt binder either as a partial substitute or as a modifier. The different effects of lignin on the rheological and mechanical performance of binders were also reported. However, these findings need to be verified at the scale of mixture, which is more correlated with the asphalt pavement performance in the field. Additionally, lignin has different forms, e.g., lignin powder and lignin fibers. How these different lignin products affect the performance of asphalt mixture also deserves in-depth research.
## 3 Finite Element Simulation
### Validation of the Time-Invariant Relationship  
The constant time-invariant relationship was demonstrated through a series of validations, each of which employed a different scenario. In these scenarios, the traffic condition was adjusted to reflect changes in vehicle status, speed, and volume. These parameters encapsulate the most prevalent time-dependent variables in the context of fluctuating traffic conditions. Should a mapping relationship, whether built upon the responses from a single scenario or deduced theoretically, be capable of encapsulating the relationships across all scenarios, it would be reasonable to deduce that the target relationship is indeed time-invariant and constant for a given bridge. The specifics of these scenarios are the following:  
1. Scenario-1--The above finite element model with a simply supported beam and quarter-vehicle;
2. Scenario-2--A vehicle with a different frequency and half the mass of Scenario-1 to simulate a different mass and a different bouncing frequency of the vehicle;
3. Scenario-3--A vehicle with different speed (the vehicle's speed in this scenario was twice that of Scenario-1 (10 m/s));
4. Scenario-4--Simultaneous vehicle traffic, whereby two vehicles traverse the beam, moving in opposite directions, and the first vehicle mirrors the physical attributes and velocity of the vehicle featured in Scenario-1, whereas the second vehicle possesses half the mass and progresses at a reduced speed of 3 m/s.  
To reconstruct the responses at 1/4 beam, dynamic responses at 3/4 beam and mid-beam were used. The transfer matrix from \(x_{3/4}\) and \(x_{1/2}\) to \(x_{1/2}\) and \(x_{1/4}\) was calculated using Equations (8a), (8b), (9) and (10). Figure 7 illustrates the reconstruction results for these four scenarios. The reconstructed beam responses matched well with the simulation results, substantiating that the relationship between sections was indeed time-invariant and constant, irrespective of differing traffic conditions. Additionally, it was supposed that changes in temperature would not affect the mode shape, and thus, the derived transfer matrix should be applicable under varying temperature conditions.  
Figure 6: Band-pass filtered (1 Hz \(\sim\) 5 Hz) high-frequency responses at three locations on the beam.
## 2 Method for Clock and Data-Acquisition Synchronization
### High-Speed Vision Node  
A high-speed vision system consisting of a high-speed camera (EoSens MC1362 produced by Mikrotron, Unterschleissheim, Germany) and a frame grabber board (microEnable IV-AD4-CL produced by Silicon Software) on a PC was used for performing the object tracking and the measurement of the object position. The camera resolution was set as 640 \(\times\) 512 pixels in the experiment. The camera shutter was triggered by the frame grabber board, and the trigger was controlled by software on the PC.  
In the high-speed vision system, object tracking was performed as follows:  
1. The background image was acquired previously. In the tracking method, the target image was extracted by background subtraction.
2. Binarization for the obtained image was executed, and the image centroid \((C_{x},C_{y})\) of the target was calculated based on the image moments given by \[C_{x} = \frac{m_{1,0}}{m_{0,0}},\] (1) \[C_{y} = \frac{m_{0,1}}{m_{0,0}},\] (2) where \(m_{i,j}\) is the \((i,j)\)-th order image moments defined as \[m_{i,j}=\sum_{x}\sum_{y}x^{i}y^{j}I(x,y), \tag{3}\]  
where \(I(x,y)\) equals the pixel value at \((x,y)\). \(m_{0,0}\) is the zero-order image moment, and \(m_{1,0}\) and \(m_{0,1}\) are the first-order image moments in \(x\) and \(y\) directions, respectively.
3. Once the object image was acquired and the centroid \((C_{x},C_{y})\) of the object was measured, a region of interest (ROI) was controlled around the centroid. The ROI size was set as 200 \(\times\) 200 pixels to reduce the computational load in the experiments.  
By repeating these sequences, the high-speed object tracking and the position calculation of the object were performed successfully.
# LoRA-Tuned Multimodal RAG System for Technical Manual QA: A Case Study on Hyundai Staria
## 4 Model Development and Training  
### Baseline Model Structure and Configuration  
The multimodal maintenance question-answering system proposed in this study consists of two pathways: Large Language Model Training Pipeline and RAG Training Pipeline, as shown in Figure 2.  
First, in the Large Language Model Training Pipeline, we performed domain continual pretraining based on maintenance description text extracted from Hyundai Staria PDF manuals. Masking ratios were set to 15% for general tokens and 25% for domain-specific terms to strengthen the language model's understanding of technical terminology. Subsequently, fine-tuning was performed based on a total of 8040 question-answering data consisting of Simple QA, RAG QA, and Multi-Turn QA. At this time, LoRA-based parameter efficiency techniques were applied, training only 0.1% of total parameters.  
The RAG Training Pipeline consists of retriever and generator modules, with contrastive learning using sentence similarity data (1200 pairs) to enable semantic-based document search for retriever improvement. Each sentence pair was constructed based on similarity evaluation scores (ICC = 0.87) from five automotive maintenance experts, adjusting embedding intervals between similar sentences based on the BAAI-bge-m3 model. The generator is based on bLLossom-8B and was trained through Instruction Tuning to automatically adjust response sentence styles according to query types (e.g., explanatory, diagnostic, procedural, etc.).  
Finally, the constructed system operates with a multistage structure consisting of retriever-generator-postprocessing modules during query processing, as shown in Figure 3.  
Figure 2: Overall system architecture.  
In Stage 1, user queries are vectorized via the BAAI-bge-m3 model, and cosine similarity is computed against the entire maintenance document embedding database. Importantly, each retrieved text segment is already linked with its corresponding image from the preannotated dataset, allowing the retriever to fetch multimodal context.  
In Stage 2, the top 5 text-image pairs with similarity scores above 0.75 are selected as context.  
In Stage 3, these multimodal contexts (text and image) and the user query are fed together into the bLLossom-8B generator, which uses Instruction Tuned templates to produce \"explanatory\", \"procedural\", or \"comparative\" responses depending on the query type.  
In Stage 4, the postprocessing module enhances the output by inserting additional visual descriptions or annotations where visual references are critical.  
In Stage 5, the system returns the final response to the user, complete with relevant images, and caches major queries for reuse.
## 1 Introduction
Thus, all of the existing adaptive quadrature schemes either introduce redundant quadrature points, or require special rules. In this paper, algorithms are proposed to enhance the efficiency of local refinement and adaptive quadrature near parametric boundaries, including:  
1. Novel a priori local mesh refinement algorithms using signed and unsigned distance measures from parametric NURBS surfaces [34; 35]. These algorithms construct and utilize implicit forms of parametric NURBS to algebraically (and non-iteratively) identify intersection between cells and immersed parametric boundaries. Figure 1: Illustration of (**a**) refinement of fields and (**b**) their associated quadrature points near immersed boundaries. 2. An adaptive quadrature algorithm using the above refinement strategy coupled with the \(k\)-dimensional tree (referred to as kd-tree) data structure to efficiently eliminate unnecessary quadrature points and special rules for cut cells.
# Optimal Control of Passive Cascaded Liquid Crystal Polarization Gratings
## 4 Diffraction Efficiency Test of the Quadrature Cascaded LCPG
### Diffraction Efficiency Test of the Orthogonal Cascaded LCPG  
An experimental test system was developed using a laser, polarization state generator, 1/4 wave plate, LCVR, LCPG, and an optical power meter to confirm the efficacy of the proposed approach, as shown in Figure 9. Table 3 presents the fundamental characteristics of the experimental apparatus. The angle of incidence of the incident light can be adjusted by turning the scale chassis while the LCVR is fixed to a base marked with a scale.  
A rotary table was used to control the injection of the laser beam into the liquid crystal adjustable phase delayer at various angles. The voltage of the liquid crystal adjustable phase delayer was then adjusted to achieve the best voltage corresponding to the various angles of incidence, and the exiting beam was then passed through the liquid crystal adjustable phase delayer. The light intensity before and after the optimization control of the LCPG was investigated to confirm that the optimal control approach may enhance the diffraction efficiency of the cascaded LCPG.  
The transmissivity test results before and after optimal control were obtained by simulating multiple measurements of liquid crystal polarization gratings with various angles of incidence, as shown in Figure 10. The above method was used to improve the diffraction efficiency of LCPGs at different incident angles.  
\begin{table}
\begin{tabular}{c c c} \hline
**Serial Number** & **Devices** & **Parameter** \\ \hline
1 & Laser & The wavelength 532.8 nm \\  & & Spot diameter \textless{} 2 mm \\ \hline
2 & Polarizer & Parallel single polarized light transmittance \textgreater{} \\  & & 70\%@533 nm \\ \hline
3 & 1/4 wave plate & The wavelength 532.8 nm \\  & & size \textless{} 25.4 \\ \hline
4 & LCVR & LCC25 \\ \hline
5 & LCPG & 5 degrees deflection \\  & & The efficiency of 98\% \\ \hline
6 & Optical power meter & Power test, no more than 0–5000 \(\text{mw}/\text{cm}^{2}\) \\ \hline \end{tabular}
\end{table}
Table 3: Basic parameters of the experimental device.  
Figure 9: Diagram of the experimental apparatus.  
By adjusting the liquid crystal adjustable phase retarder voltage under various deflection angles, the diffraction efficiency of the cascaded LCPGs can be increased (as illustrated by the experimental findings in Figure 8). It has been demonstrated that the technique described in this study can increase the diffraction efficiency of high-order LCPGs, and the increase can be as high as 10% depending on the deflection angle.