esa-sceva/satcom-chunk-collection huggingface dataset:
# Aroma Volatiles in Litchi Fruit: A Mini-Review
## 2 The Profiles of VOCs in Litchi Fruit
By comparing the detection results with the NIST database and referencing the relevant literature, it was found that \"Shuangjianyuhebao\" (SJYHB) had 41 VOCs, in which tetradecamethyl cycloheptasiloxane, butyl acrylate, dodecamethyl pentasiloxane, diisobutyl phthalate, and \(\beta\)-caryophyllene might be the main aromatic compounds [29]. [PERSON] et al. [24] detected 42, 41, and 37 VOCs in \"Zhengfeng\" (ZF), \"Xiangli\" (XL) and \"Jizuili\" (JZL), respectively. These three cultivars had high rose oxide aroma activity. Additionally, (E)-2-hexanal, hexanal, and 1-octen-3-ol in ZF also had high OAV values, indicating that ZF fruit presents a more complex aroma than other cultivars. There were a few VOCs in \"Wuyejiu\" (WYJ), \"Lizhiwang\" (LZW) and \"Gualv\" (GL). The WYJ fruit had 34 VOCs in which acetic acid, isoamyl alcohol, and methyl acetate were the most abundant [37]. The LZW fruit had 28 VOCs, out of which ethyl acetate, acetoin, and 1-methoxy-2-propanol were the main constituents [30]. The GL fruit had 22 VOCs, and the relative contents of benzyl acetate, citronello!, and ethyl linoleate were found to be high [28]. Nevertheless, [PERSON] et al. [38] found that acetoin, geraniol, 3-methyl-2-butten-1-ol, octanoic acid, 2-phenylethylanol, _cis_-ocimene, and butyric acid were the major volatile compounds conducive to the aroma of an unknown litchi cultivar. Five litchi cultivars from South Africa were used for the detection of the volatile aroma profiles. In particular, a combination of different detection methods, including GC-O, GC-MS, GC-PFPD, and GC-FTIR, were applied. Studies showed that the three cultivars \"Mauritius\", \"Brewster\" and \"Hak Ip\" had common 24 odor components, including acetaldehyde, ethanol, ethyl-3-methylbutanoate, diethyl disulfide, 2-methyl thiazole, 1-octen-3-one, _cis_-rose oxide, hexanol, dimethyl trisulfide (DITS), R-thujone, methional, 2-ethyl hexanol, citronell, (E)-2-nonenal, linalool, octanol, (E,Z)-2,6-nonadienal, menthol, 2-acetyl-2-thiazoline, (E,E)-2-4-nonadienal, \(\alpha\)-damascenone, 2-phenylethylanol, \(\alpha\)-ionone, and 4-vinylguaiacol [39]. \"Mclean's red\" produced 19 kinds of VOCs, and germacrene D and \(\alpha\)-muroulene were the two compounds with the highest contents [40]. [PERSON] and [PERSON] [41] found that hexan-1-ol, (E)-hex-2-en-1-ol, oct-1-en-3-ol, \(\beta\)-bisabolol, limonene, \(p\)-cymene, terpinolene, \(\alpha\)-acoradiene, 3-methylbutyl acetate, geranylethyl ether, 2-methylpropan-1-ol, 3-methylbutyl-3-en-1-ol, 3-methylbutyl-2-en-1-ol, citronello!, geraniol, 3-hydroxybutan-2-one, and 3-methylbutan-1-ol were the main VOCs for an unknown litchi cultivar.
# Quantification of the Effective Detectable Period for Concrete Voids of CLP by Lock-In Thermography
## 2 Theory  
### Lock-In Thermography (LIT)  
Among the TT technologies, the LIT technique, which utilizes external energy, applies a heat load in the form of a controllable harmonic function to the inspection object and measures the temperature change formed on the surface of the inspection object with an infrared (IR) camera. It is a technique that demodulates the amplitude and phase changes of the measured data and compares and analyzes the difference to check for the existence of defects [16].  
The LIT technique utilizes thermal changes caused by periodic excitation rather than instantaneous thermal changes, so it can detect minute differences in defects in the inspection target and has the effect of reducing external influences such as uneven heat load or emissivity.
## 3 Electron Beam Transport for Ideal Magnetic Elements
Figure 5: Simulation of the horizontal (**red**) and vertical (**blue**) (relative energy spread (RMS)) beam envelope of the optics (**a**) “undulator”, (**b**) “slit-undulator”, (**c**) “undulator-entrance”, and (**d**) “undulator-exit” along the line for a flat-top energy spectrum beam of 176 \(\pm\) 0.3 MeV, with \(\sigma^{\prime}_{z,i}\) = 2 mrad RMS and \(\sigma^{\prime}_{x,i}\) = 3.12 mrad RMS. Transversal distribution of the electron beam at the undulator entrance (**a1–d1**), center (**a2–d2**), and exit (**a3–d3**) for the low divergence beam case (parameters of Figure 2a and Table 1) associated with the corresponding magnetic elements settings given in Table 3. Transport line elements representation (**black**) with screens (**vertical line**), dipoles (**rectangle**), and focusing (**rectangle with indentation**) and defocusing quadrupoles (**triangle on top**). (**e**) Vertical aperture along the longitudinal direction of the transport line. Figure 6a,b presents the envelope evolution with the \"Undulator\" optics for a flat-top distribution for different energies: The nominal energy (176 MeV) electrons are focused at the center of the undulator, while the lower energy (172 MeV) (resp. higher energy (180 MeV)) ones are focused before (after) the undulator. The chromatic dependence induces a cross shape on the focus spot at the screen before and after the undulator (Figure 5a1,a3), due to the various energies being focused at different horizontal and vertical positions instead of the center of the undulator. Figure 6c shows the emittance and the charge at the undulator center for different energies. The emittance is minimum at 176 MeV, in which the optics has been designed. The vertical (horizontal) emittance increases by a factor of 1.5 (1.05) for 172 \(\pm\) 0.3 MeV and by a factor of 1.26 (1.02) for 180 \(\pm\) 0.3 MeV. No charge is lost in any of the three cases.
## 4 Simulation Results
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Type** & **Parameter** & **Value** \\ \hline Common: & Frequency & 20 GHz \\  & Bandwidth & 100 MHz \\ The GEO satellite system: & Satellite orbit height & 35,786 Km \\  & Equivalent isotropically radiated power (EIRP) & 40 dBW / MHz \\  & Satellite Tx antenna max gain & 58.5 dBi \\  & 3 dB beamwidth & 0.1765 degree \\  & Satellite beam diameter & 110 Km \\  & I/N of terminals & \(-12.2\) dB \\ The UD-LSC system: & Satellite orbit height & 1200 Km \\  & The number of the LEO orbit planes & 18 \\  & The number of LEO satellites in each orbit plane & 75 \\  & EIRP & 10 dBW / MHz \\  & Satellite Tx antenna max gain & 38.5 dBi \\  & 3 dB beamwidth & 1.7647 degree \\  & Satellite beam diameter & 40 Km \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The main parameters of UD-LSC and GEO satellite systems. Figure 4 simulates the sum of satisfaction performance comparison against a different number of active GEO beams \(G\), where we set \(K=4\), and the average traffic is 0.5 Gbps. As the number of active beams of the GEO satellite system increases, the LEO satellite system suffers more interference, so that the satisfaction level gradually decreases. When \(G<=4\), the proposed MGPA-SPA scheme outperforms other baseline schemes. When \(G>=5\), the MGBA-UPA scheme has a larger sum of satisfaction than the MGBA-SPA. Compared with MGBA-UPA, MGBA-SPA includes a constraint that the interference to GEO terminals does not exceed the threshold. Therefore, MGBA-SPA is more sensitive to the number of active beams in the GEO system. Figure 4: The sum of satisfaction performance comparison against different numbers of active GEO beams \(G\). Figure 3: The sum of satisfaction performance comparison against different numbers of cooperative LEO satellites \(K\). Figure 5 simulates the sum of satisfaction performance comparison against different average traffic requests of LBCs, where we set \(K=4\) and \(G=3\). Since the transmit power is fixed, the sum of satisfaction declines for all schemes with the increase of the average traffic demand. When the average traffic \(T_{aver}=0.25\) Gbps, both the MGBA-UPA and MGBA-SPA scheme can achieve a maximum sum of satisfaction, \(\Phi_{sum}=19\). With \(T_{aver}>1\) Gbps, the performance gap between the proposed MGBA-SPA scheme and the others is about 2. Figure 6 simulates the provided capacity of the proposed MGBA-SPA scheme of each ground LBC, where \(K=4\), \(G=3\), and the average traffic is 0.25 Gbps. The simulation result in Figure 6 indicates that the proposed algorithm can achieve the traffic balancing for all 19 LBCs. The fairness between different cells is guaranteed. From Figure 6, we can find that some beams have wasted capacity, such as beam indexes 2, 4, and 7, since the power allocation matrix \(\mathrm{P}\) is a relaxed solution by adopting SCA.
###### Abstract  
This study presents a comprehensive analysis of information diffusion in social networks with time delay mechanisms. We first analyze real Reddit thread data, identifying limitations in the sample size. To overcome this, we develop synthetic network models with varied structural properties. Our approach tests three delay types (constant, uniform, exponential) across different network structures, using machine learning models to identify key factors influencing information coverage. The results show that spread probability consistently impacts diffusion across all datasets. Gradient Boosting models achieve \(\mathbb{R}^{2}=0.847\) on synthetic data. Random networks with a constant delay mechanism and high spread probability (0.4) maximize coverage. When verified against test data, peak speed time emerges as the strongest predictor (r = 0.995, \(p<0.001\)). Our findings provide practical recommendations for optimizing information spread in social networks and demonstrate the value of integrating real and synthetic data in diffusion modeling.  
Keywords:information diffusion; social networks; time delay mechanisms; population dynamics; synthetic networks; machine learning; Reddit threads; comparative modeling +
Footnote †: journal: Applied sciences
## 1 Introduction
These challenges must be addressed to ensure the confidentiality, integrity, and availability of data and services [11]. Addressing these challenges requires a comprehensive security strategy that combines encryption, authentication, access controls, and monitoring mechanisms. It also involves the collaboration of fog computing stakeholders to develop standardized security protocols and best practices that suit the unique characteristics of the fog computing paradigm [12]. This work aims to design a lightweight mutual Authentication and Key Agreement protocol tailored for the edge-fog-cloud environment, specifically integrated with the 5G network. Hereafter, we will call it the \"3-ier AKA\" protocol. This protocol provides secure and stateless authentication mechanisms that address the unique challenges posed by the distributed nature of the cloud, fog, and edge computing paradigms. This involves designing mechanisms that allow for the seamless transfer of authentication credentials and cryptographic keys, ensuring continuous service without compromising security while accommodating the dynamic nature of the 5G network and the unique characteristics of the edge-fog-cloud computing. Incorporating a lightweight cryptographic technique with the Advanced Encryption Standard (AES), [13] aims to enhance authentication's overall security and performance in this complex computing environment. To achieve this objective, this work has the following main contributions:  
* Analyzing the security requirements and constraints of the edge-fog-cloud environment, considering factors such as resource limitations, network latency, and potential attacks during first authentication and handover scenarios. A detailed analysis is given in Section 2.2. Based on this analysis, lightweight cryptographic techniques and protocols are designed and developed to enable secure and efficient authentication. The protocol design is explained in Section 3. * The designed protocol is further integrated to support handover authentication, enabling the mobility characteristic of fog computing and minimizing authentication delays. The handover protocol design is presented in Section 4. * The designed protocols are evaluated through simulations to assess their security, performance, and scalability in edge-fog-cloud scenarios. The detailed evaluation is presented in Section 5. The rest of this paper is organized as follows: Section 2 presents a background and a review of related work. Section 3 presents the proposed model, which is derived based on the characteristics of the edge-fog-cloud computing environment and its requirements. Section 4 presents the proposed mutual authentication protocols. Section 5 evaluates the proposed protocol. Section 6 analyzes the features of the proposed security protocols. Finally, Section 7 presents the conclusions and future work.
## 2 Relevant Theory
### Reflectance Denoising Module  
The Transformer structure used for image denoising, referred to as the Noise Reduction Transformer (NR-Transformer), is designed based on the Vision Transformer (ViT) architecture [21], as illustrated in Figure 3. Unlike conventional Transformer models that embed images using fixed-size patches at the input stage, this structure embeds the feature maps at the pixel level within a separate Transformer module. This allows for more comprehensive aggregation of multi-scale feature information and more effective suppression of global noise signals. However, the original ViT architecture lacks convolutional layers, resulting in a weaker feature extraction capability compared to CNNs. This limitation often leads to slow convergence during training and necessitates larger datasets and more training epochs. Although the self-attention mechanism involves fewer trainable parameters, it introduces significant computational overhead, thereby increasing the network's runtime and degrading its real-time performance. To address these issues, a hybrid CNN+Transformer  
Figure 2: Network model structure. The network consists of four parts: image decomposition module, multi-scale brightness-enhancement module, reflectivity denoising module, and image segmentation module.  
structure is adopted in the reflectance denoising module. By combining the localized feature learning capabilities of convolutional networks with the global dependency modeling strength of Transformer architectures, this approach effectively mitigates noise of different granularities across multiple spatial scales.
## 5 Vertex Cover
### Algorithm for Unit Disk Graphs  
We present a local approximation algorithm for minimum vertex cover for unit disk graphs. Let \(G=(V,E)\) be a connected unit disk graph. The algorithm works as follows: First we check whether \(|V|\geq 2\). If \(|V|=1\) then there are no edges in \(G\) that need to be covered so we define \(VC:=\emptyset\). If \(|V|\geq 2\) we assign all vertices to the set \(VC\). We output \(VC\). We present the above description as Algorithm 7.  
```
1// Algorithm is executed independently by each node \(v\);
2 if\(|V|\geq 2\)then assign \(v\) to \(VC\);
3 else Do not assign \(v\) to \(VC\);
```  
**Algorithm 7**Local algorithm for computing a vertex cover for a unit disk graph \(G=(V,E)\)  
We prove the correctness of Algorithm 7 in Theorem 12.  
**Theorem 12**.: _Let \(G\) be a unit disk graph. Algorithm 7 has the following properties:_  
1. _The computed set_ \(VC\) _is a vertex cover for_ \(G\)
2. _Let_ \(VC_{OPT}\) _be an optimal vertex cover. It holds that_ \(|VC|\leq 6\cdot|VC_{OPT}|\)_._
3. _Whether or not a vertex_ \(v\) _is in_ \(VC\) _depends only on the vertices at most one hop away from_ \(v\)_, i.e. Algorithm_ 1 _is local._
4. _The processing time for a vertex_ \(v\) _is constant._  
Proof.: If \(|V|<2\) this implies that \(G\) contains no edges and \(VC=\emptyset\) and \(VC_{OPT}=\emptyset\). So in this case \(VC\) is indeed a vertex cover for \(G\) and \(|VC|\leq 6\cdot|VC_{OPT}|\). If \(|V|\geq 2\) then \(VC=V\). So \(VC\) is indeed a valid vertex cover for \(G\). The approximation factor follows from Theorem 11.  
In order to check whether \(|V|\geq 2\) we only need to examine if there are vertices which are at most one hop away from a given vertex \(v\). So the locality of Algorithm 7 is one hop.  
Checking whether there are vertices which are adjacent to \(v\) and assigning \(v\) to \(VC\) can be done in constant time, so the processing time of Algorithm 7 is constant.
# Effects of Atmospheric Turbulence on Lensless Ghost Imaging with Partially Coherent Light
## 3 Numerical Examples and Analysis
The effect of the diffraction and turbulence on the transverse coherence width is different, making the variation of the visibility with propagation distance hard to predict. Figure 4: Lensless ghost imaging for different propagation distances (**a**) in free space, (**b**) in bistatic turbulence with \(C_{n}^{2}\ =\ 5\ \times\ 10^{-14}\) m\({}^{-2/3}\) and (**c**) in monostatic turbulence with \(C_{n}^{2}\ =\ 5\ \times\ 10^{-14}\) m\({}^{-2/3}\). Solid lines \(z=1\) m; dashed lines \(z=150\) m; dotted lines \(z=300\) m; dashed dotted lines \(z=400\) m. In (**c**), the solid line and the dashed line are almost overlapped. Figure 5: Visibility of lensless ghost image against the propagation distance. Solid line: free space; dashed line: monostatic turbulence; dotted line: bistatic turbulence.
# On-Board Ship Detection in Micro-Nano Satellite Based on Deep Learning and COTS Component
## 4 The Composition of Ground Demonstration and Verification System
### Ground User Equipment  
According to the requirements of different tasks, the ground user equipment completes the functions of intelligent processing application scene configuration, parameter configuration and instruction control with the remote sensing satellite. The application scene configuration is to select the specific algorithm, and parameter configuration includes satellite data information, the selection of intelligent algorithm model and the data transmission mode. Instruction control includes image simulation, data generation, intelligent processing and product generation instruction.
## 4 Application of Moisture Identification and Algorithm Comparison
### Comparison of Selection Algorithms  
The Pearson coefficient method and principal component analysis method were used for the selection and dimensionality reduction of the above six feature parameters, and then compared with the two-step selection algorithm that is proposed in this study.
# Research Progress on Curved Plates in China: Applications in Architecture
## 5 Future Directions
### Acoustic Characteristics of Curved Plates  
First, sufficient acoustic diffusion can improve the distribution of sound energy and sound fields inside theaters. The combination of curved diffusers with different sizes and curvatures combined with surface undulating structures will become a model (standard configuration) of sound diffusion system design. At the same time, the design will continue to develop towards the direction of optimizing surfaces to meet acoustic and aesthetic needs. However, most existing research is based on actual engineering design verification, and relevant theoretical and computer simulation (i.e., acoustic finite element simulation) research is still lacking. Therefore, for indoor acoustic effects, developing a mechanism and numerical calculation to optimize surfaces and improve indoor acoustic effects in theaters is one of the future development directions.  
Second, with the flowering of stage performance forms, modern acoustic and electric technology is developing rapidly, especially sound source vocalization technology (such asdirectional vocalization) and innovative layout schemes are in the ascendance, which is bound to drive innovation in acoustic effect creation. For each new sound source system, the development of the corresponding complete set of acoustic characteristics of curved plates or structures will be a research hotspot closely related to the acoustic industry in the future.  
Third, architectural acoustics is not limited to the indoor acoustic design of theaters, and in fact, for most buildings, research on the partitioning of external noise is more urgent. At present, most newly built buildings in Chinese cities are high-rise structures, and because of the high population density, urban noise has become a problem that cannot be ignored. The characteristics of plane reflection and convex diffusion using curved plates are used to optimize building walls, roofs, and other envelope structures. This will become an important research direction in the future.
## 2 Results  
Prior to analysis of the potential UVA protective effects of (2'S)-columbianetin, its cytotoxicity was assessed by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolzolium bromide (MTT) assay in human dermal fibroblast (HDF) cell line. Treatment with varying concentrations (0, 1, 5, 10, 20 and 25 \(\upmu\)M) of (2'S)-columbianetin for 48 h showed a dose-dependent cytotoxicity in HDFs with an IC\({}_{50}\) value of 93.89 \(\upmu\)M (Figure 2A). Cell viability was above 90% up to 10 \(\upmu\)M, which was chosen as the highest dose of treatment. UVA irradiation was carried out at 10 J/cm\({}^{2}\) dose which was previously reported to be non-toxic for 24 h while inducing photoaging mechanisms (MMP-1 activation and inhibition of collagen synthesis) in HDFs [23]. [PERSON] et al. [22] reported that (2'S)-columbianetin showed a significant scavenging effect against UVB-mediated reactive oxygen species (ROS) generation in keratinocytes. In the current study, any scavenging effect of (2'S)-columbianetin against UVA-mediated reactive species was investigated in human dermal fibroblasts by measuring nitrate amount in cell culture medium as a marker for reactive nitrogen species (NO) generation. UVA irradiation significantly increased the NO generation in HDFs (Figure 2B). The treatment with (2'S)-columbianetin dose-dependently decreased the UVA-induced NO generation suggesting that it might attenuate the UVA-induced reactive species generation in addition to reported protective effects against UVB.  
Figure 1: Chemical structure of (2’S)-columbianetin.