esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Discussion
Studies have demonstrated that browning and growth of foodborne pathogens during postharvest storage are major factors reducing the quality and economic value of fresh-cut apples [35]. _Erwinia carovova_ induces apple soft rot, characterized by tissue maceration, foul odor, and liquefaction of flesh, predominantly occurring during late storage stages or via wound-mediated infections. The sorbitol-chelated calcium treatment directly inhibits fungal and bacterial pathogens (e.g., _Penicillium_, _Erwinia carovova_) by stabilizing membrane structures and limiting enzymatic spoilage, as evidenced by 34.86% lower total microbial counts and up to 51.71% reduced specific pathogen populations compared to controls, thereby delaying spoilage and maintaining postharvest quality. The sorbitol-chelated calcium (T2) treatment induced distinct metabolic reprogramming in fresh-cut apples, as evidenced by PCA and differential metabolite analyses, which revealed 498 unique metabolites in T2 compared to T1, predominantly enriched in flavonoid biosynthesis, tyrosine metabolism, and isoflavonoid biosynthesis pathways. These pathways drive the accumulation of quercetin, hydroxytyrosol, and isoflavones--critical for pigmentation, enzymatic browning suppression, and antimicrobial activity [36]. Concurrently, T2 enhanced volatile profiles, with total aroma substances and esters peaking 31.40% and 61.79% higher than for CK, respectively, driven by elevated alcohols (43.78%) and aldehydes (41.49%). This dual enhancement of non-volatile and volatile metabolites underscores T2's role in flavor preservation and pathogen inhibition, likely mediated by calcium's stabilization of cell walls (reducing nutrient leakage) and sorbitol's antioxidative action, which synergistically limit microbial colonization and oxidative spoilage [37]. The treatment's ability to sustain higher levels of aroma-related esters and stress-responsive phenolics aligns with its efficacy in maintaining postharvest quality, positioning sorbitol-chelated calcium as a multifaceted solution for fresh-cut apple preservation. [PERSON] et al. reported that the total aroma substance and ester contents correlate with the expression of three genes: _AAT1_, _AAT2_, and _LOX_[38]. The content of alcohols and aldehydes in apple aroma is correlated with the expression of _HPL_ and _ADH_ genes [39]. These proteins modulate transcription factors that upregulate genes such as _AAT1_ and _LOX_, enhancing the biosynthesis of volatile compounds [40]. The results of the present study revealed that the sorbitol-chelated calcium treatment group had a beneficial effect on the improvement of fruit aroma substances, with the total aroma substances and estersbeing higher than those in other treatments. This is because the sorbitol-chelated calcium treatment upregulated the expression levels of _AAT1_, _AAT2_, and _LOX_ in the fruit. By modulating these transcriptional networks, sorbitol-chelated calcium enhances enzymatic efficiency in volatile biosynthesis, thereby improving total aroma and ester content, as observed in this study.
###### Abstract  
For classified and sensitive electronic documents within the scope of enterprises and organizations, in order to standardize and strengthen the confidentiality management of enterprises and meet the actual needs of secret text classification, a document automatic classification optimization method based on keyword retrieval and the kNN classification algorithm is proposed. The method supports keyword classification management, provides users with keywords of multiple risk levels, and then combines a matching scanning algorithm to label keywords of different levels. The text with labels is used as the training set of the kNN algorithm to classify the target text and realize the classification protection of text data. Aimed at solving the shortcomings of large feature vector dimension, low classification efficiency, and low accuracy in existing kNN text classification methods, an optimization method is proposed using a feature selection algorithm and a kNN algorithm based on an AVX instruction set to realize real-time classification of massive texts. By constructing a keyword dictionary and an optimized feature vector, parallel calculation of the feature vector weight and distance vector is realized, and the accuracy and efficiency of text classification are improved. The experimental results show that the multi-classification effect of the feature selection algorithm used in this paper, _tf-DE_, is better than that of the traditional _tf-idid_ algorithm, and the classification effect of kNN is comparable to that of the support vector machine (SVM) algorithm. With the increase in feature vector dimensions, the classification effect of the text classification algorithm is improved and the classification time also increases linearly. The AVX-256 acceleration method takes about 55% of the time of the original version, thus verifying the effect of multi-classification of massive texts for document confidentiality management.  
kNN; text classification; AVX-256; feature vector +
Footnote †: journal: Applied Physics Letters
# Nature-Based Solutions in Urban Areas: A European Analysis
## 2 Sustainability in the Built Environment
### Nature-Based Solutions  
NbS is a new concept that started to be used at the beginning of the 21 st century and was later adopted by several global institutions [24]. NbS has evolved as an \"umbrella\" concept [25; 26] that incorporates several existing concepts and practices [27] that can be applied to the strategic dimension, spatial planning dimension, soft engineering dimension, and performance dimension (Figure 1) [25]. The most recent EC report on NbS states that this concept embodies new ways of approaching socioecological adaptation and resilience, with equal confidence in the social, environmental, and economic domains [25]. Figure 1: Overview of nature-based concepts and their relationship to existing key concepts. Adapted from [25; 28]. NbS provide several beneficial ecosystem services [5; 26], such as their ability to store carbon and regulate water flow [29] in order to achieve desired outcomes in urban spaces, such as disaster risk reduction, microclimate regulation, improved human health, and socially inclusive green growth [5; 8; 28; 29]. In this sense, NbS can help in facing social and economic challenges within the sustainable development paradigm, providing benefits that meet--directly and indirectly--SDG 2, SDG 3, SDG 6, SDG 8, SDG 10, SDG 11, SDG 12, SDG 13, SDG 14, and SDG 15 [28]. Indeed, the ability to simultaneously achieve multiple SDGs is a big part of what makes NbS implementation attractive [25; 30]. One of the challenges that can be addressed using NbS is the urban heat island (UHI) effect, with respect to which these solutions can be effective in mitigating air pollution and reducing air temperature in urban areas [10; 31]. Systems and technologies integrated into nature-inspired construction projects (green buildings), such as green roofs and green walls--green facades, vertical gardens, or living walls--are opportunities to foster a transformation in buildings by creating effective NbS solutions [9; 10; 25; 29], reducing thermal stress in cities, and improving air quality [28; 31]. NbS also offer synergies in reducing flood and drought risks while improving water quality and quantity [29], meeting the objectives of various European regulations such as the Floods Directive and the Water Framework Directive [28; 32]. In general, NbS can be grouped according to sectors and thematic areas of social importance [28; 33]: (I) water management, (II) forests and forestry, (III) agriculture, (IV) urban areas, and (V) coastal areas (Table 1).
## 5 Conclusions  
The approach illustrated in this paper, by incorporating improved maps of soil properties and by assessing seasonal constraints on productivity and LAI\({}_{\rm max}\) in a more functional manner, provides predictions that can be validated: (a) at sites where eddy-flux measurements of CO\({}_{2}\) and water vapor exchange are being measured [78]; (b) at decadal revisited Forest Inventory and Analysis survey plots; and (c) through independent measurements acquired by various sensors borne on aircraft and satellites orbiting the Earth [59; 79]. With even moderate refinement in the mapping of soil properties, we achieved closer agreement between predicted and measured growth than previously reported for parts of the US Pacific Northwest [80].  
Finally, the analyses presented in this paper show that conditions across the entire study area have been generally warmer since 2000 compared to the period of 1950-1975, a trend particularly evident in the boreal forests of Canada [71, 72]. The U.S. Global Change Program substantiates that rapid warming and melting of winter snowpack have already occurred over the last few decades and predict the trend to continue and to accelerate. The full implications of such changes on western forests are just beginning to be appreciated, with expanding areas of forests affected by fire, insects and disease (_i.e._, [67, 68]). Without limitations on the rise of greenhouse gases, the forests of the future may be in a continuous state of transition, bringing to scientists and to society unforeseen challenges to predict and with which to cope.  
We are indebted to [PERSON] at the University of British Columbia for deriving estimates of solar radiation values for the entire study area and to [PERSON] for editorial suggestions. This work was supported by NASA grant NNX11A029G from the program for Biodiversity and Ecological Forecasting.  
The authors declare no conflicts of interests.
###### Abstract
By promptly addressing errors, operators can prevent accidents, injuries, and damage to cargo or infrastructure, safeguarding personnel's well-being and preserving the integrity of terminal facilities [9]. 4. Reduction of Maintenance Costs: Detecting, diagnosing, and predicting errors early can help reduce maintenance costs associated with crane operations. By identifying potential errors before the said errors escalate into significant failures, operators can implement preventive and prescriptive maintenance measures to address underlying issues and prolong the lifespan of equipment [10]. This proactive maintenance approach helps to minimise downtime, repair costs, and operational disruptions, ultimately leading to cost savings for terminal operators [11]. 5. Compliance with Regulatory Standards: Timely error detection ensures compliance with regulatory standards and industry regulations governing crane operations. By promptly identifying and addressing errors, operators can maintain adherence to safety guidelines and operational protocols mandated by regulatory authorities. This compliance not only ensures the safety of personnel and assets but also helps to avoid potential fines and legal liabilities associated with non-compliance [12; 13]. In summary, timely error identification and prediction are essential in optimising crane performance, ensuring safety in container crane operations, and benefiting stakeholders across the maritime supply chain.
# A Survey of Wi-Fi 6: Technologies, Advances, and Challenges
## 5 SR in Wi-Fi 6
### Mechanisms for Spatial Reuse in Wi-Fi 6
#### 5.3.3 Overlapping BSS Packet Detection (OBSS PD)  
With Overlapping Basic Service Set Packet Detect (OBSS PD), nodes can disregard inter-BSS traffic received with a low signal strength. To improve the overall throughput, a novel Clear Channel Assessment (CCA) threshold is defined for inter-BSS traffic called the \(OBSS\_PD_{level}\). If a station receives an inter-BSS frame, it updates its inter-BSS NAV only if the sensed RSS is larger than the \(OBSS\_PD_{level}\).  
The \(OBSS\_PD_{level}\) and \(TX\_PWR\) as the transmission power of a station have an inverse relationship. Thus, a higher \(OBSS\_PD_{level}\) implies a lower \(TX\_PWR\) to avoid interference with transmissions in other BSSs. The value for the \(OBSS\_PD_{level}\) is in the range of \(OBSS\_PD_{min}=-82\) dBm, which corresponds to the normal CCA threshold and \(OBSS\_PD_{max}=-62\) dBm [5; 12]. The transmission power \(TX\_PWR\) is calculated using the following equation:  
\[TX\_PWR=TX\_PWR_{ref}-(OBSS\_PD_{level}-OBSS\_PD_{min}) \tag{1}\]  
In other words, a large \(OBSS\_PD_{level}\) allows a node to overhear inter-BSS traffic with a low signal strength. Moreover, the mechanism permits a station to start transmission in the presence of inter-BSS traffic if it reduces the transmission power of its own signal.  
Differentiated OBSS PD treatment of inter-BSS traffic may be helpful if some of them are close and others are further away. To that end, OBSS PD has been extended with spatial reuse groups (SRGs). One SRG is a set of BSSs for which specific OBSS PD parameters are defined [12]. Finally, we have:  
* CCA parameters for intra-BSS traffic;
* OBSS PD parameters for inter-BSS traffic that is part of the same spatial reuse group;
* General OBSS PD parameters for the remaining inter-BSS traffic.
## 2 Materials and Methods
### Pre-Processing Methodology  
The first step in the pre-processing methodology is the application of a quality assurance procedure to the available dataset. This is a regular practice of outlier removal and missing data imputation techniques dictated by experience in the processing of large time series of measurements [32; 37]. Specific criteria are defined for cleaning up the data, with regard to irradiance, airmass, and inverter power output. Recordings with zero values of inverter power output are rejected and the same is done with those with irradiance values <50 W/m\({}^{2}\). Airmass is another important indicator that should be taken into account with data preprocessing [38]. According to previous experience, data records with AM > 10 are also rejected.
## 3 Implementation and Evaluation of the Method
### Computational Cost  
With the metadata stored in the database corresponding to the runtime of the hash function, it was possible to determine the computing time according to the mobile device and the duration of the voice recording. This relationship is shown in Figure 5, where the \(X\)-axis has a logarithmic scale (base 2). Based on the obtained data, it can be said that the execution time will depend on the characteristics of the device, i.e. the lower are the resources, the longer is the execution time, although in general terms the execution time is low.  
Figure 4: Histogram of \(PCC\) between all the obtained codes.  
Figure 5: Runtime of the hash function based on recording duration, according to the mobile device.  
In Figure 5, it is possible to determine that the runtime of the proposed hash function for the mobile device Moto g is related to Equation (16), where \(x\) is the duration of the input recording.  
\[y\approx-1\times 10^{-5}x^{2}+0.0303x-0.0365 \tag{16}\]  
It is also possible to determine that the execution time of the proposed hash function for Nexus 5x is related to Equation (17).  
\[y\approx 2\times 10^{-6}x^{2}+0.0033x+0.0308 \tag{17}\]
###### Abstract
Even if part of the sequences is intercepted, the remaining sequences are nearly impossible to decipher without the proper decoding mechanism. Loss Tolerance: The CCES scheme converts the secret message into multiple sequences using end spreading, which enhances its ability to maintain communication even under adverse network conditions such as packet loss or network interference. The redundancy of end spreading sequences allows for the recovery of the original message despite packet loss, providing robustness against environmental disturbances. Robust Synchronization: Unlike traditional synchronization methods that rely on reference clocks, the CCES scheme employs end spreading sequences to synchronize communication between the sender and receiver. This mechanism is robust against network latency and jitter, ensuring reliable communication even in high-speed end hopping systems [18]. In summary, the proposed CCES model represents a significant advancement in covert communication systems by leveraging end spreading to address the vulnerabilities of existing covert channels. This model offers a powerful solution for secure communication in modern network environments, where resilience, confidentiality, and resistance to detection are essential. The rest of this paper is organized as follows: In Section 2, we review the related work regarding network covert channels and proactive network defense technologies. The model sketch of CCES and scheme implementation is described in Section 3. Section 4 introduces the evaluation metrics used to evaluate the covert channel of the network. Section 5, we implement extensive experiments to validate the channel characteristics practically. We conclude this paper in Section 6.
# Uni-Planar MIMO Antenna for Sub-6 GHz 5G Mobile Phone Applications
## 2 Proposed Uni-Planar MIMO Antenna
### Characteristics of Proposed MIMO Antenna  
The simulated S-parameters of the proposed MIMO antenna are shown in Figure 4. From Figure 4, it is observed that the designed MIMO antenna is resonating well for the band of interest, i.e., 3.5 GHz. Furthermore, the minimum isolation between adjacent antenna elements is noted to be \(>\)10 dB. A variation is observed in the \(S_{11}\) response, which mainly occurred due to feeding points and different placements of antenna elements on the smartphone PCB, as shown in Figure 1. In addition to this, the mainboard is rectangular in nature, which could cause some discrepancies in the frequency response and couplings, mainly between even and odd port numbers. However, one can adjust the desired frequency band by modifying design parameters explained in Figure 3 [20].  
The designed antenna's simulated three-dimensional (3-D) gain patterns are presented in Figure 5. The antenna generates different vertical and horizontal polarized radiation patterns for the chosen frequency band, as shown in the diagram. In addition, as demonstrated in Figure 5, the antenna has a gain of \(\sim\)3.6 dBi. The resulting radiation patterns further confirm that the MIMO antenna adheres to pattern diversity, which is a desirable feature for future smartphone applications.  
One of the most critical aspects in determining the performance of MIMO antennas is the ECC. For practical applications, the ECC should be \(<\)0.5 and, ideally, it is \(\approx\)0. The ECC can be determined by using the S-parameters of the MIMO system as [21]:  
\[\text{ECC}=\frac{|S_{jl}^{*}S_{ji}+S_{ij}^{*}S_{ii}|^{2}}{\big{(}1-|S_{jil}|^{2 }-|S_{ji}|^{2}\big{)}\big{(}1-|S_{ij}|^{2}-|S_{ii}|^{2}\big{)}} \tag{1}\]  
where \(S_{ii}\) and \(S_{jj}\) are reflection coefficients, while \(S_{ji}\) and \(S_{ij}\) are MIMO antenna transmission coefficients.  
Figure 4: Simulated S-parameters of the proposed sub-6 GHz MIMO antenna.  
As shown in Figure 6a, the value of ECC for the intended frequency band (3.5 GHz) is \(<\)0.01. The results also demonstrate high isolation between antenna elements, which is a crucial factor for simultaneous operation. The DG of the suggested MIMO antenna, on the other hand, can be calculated as follows [22]:  
\[\text{DG}=10\Big{(}\sqrt{1-\text{ECC}^{2}}\Big{)} \tag{2}\]  
For the presented MIMO antenna, the DG value is noted to be \(>\)9.9 dB, as shown in Figure 6b.  
The total active reflection coefficient (TARC) is another significant metric to consider while evaluating the MIMO antenna's performance and can be evaluated as follows [23]:  
\[\text{TARC}=\sqrt{\frac{{{{(S_{mm}+S_{mn})}^{2}}{{(S_{mm}+S_{mn})}^{2}}}}{2}} \tag{3}\]  
The results demonstrate that the suggested MIMO antenna delivers TARC \(>\)20 dB for the band of interest, as illustrated in Figure 6c.  
Figure 5: Three-dimensional gain patterns of the proposed sub-6 GHz MIMO antenna.
# Spatiotemporal Mechanical Effects of Framework-Slope Systems Under Frost Heave Conditions
## 4 Development of Coupled Multi-Field Numerical Model  
### Fundamental Assumptions  
To investigate the evolution of frost heave processes in seasonally frozen slopes and to understand the internal ice-water phase transition mechanisms that drive anchor force redistribution from the slope crest to the toe, a fully coupled thermo-hydro-mechanical (THM) model was developed using COMSOL Multiphysics v6.2 (COMSOL AB, Stockholm, Sweden). The model represents a frame-anchored slope subjected to freezing and thawing, and the following assumptions were made to simplify the simulation:  
1. The initial state of the slope is stable, and there is no interaction force between the frame and the slope surface.
2. Both frozen and unfrozen soils are assumed to be isotropic.
3. Heat loss during the freeze-thaw cycles are neglected.
4. The moisture field is considered closed, meaning the external water supply and evaporation are ignored.
5. A deformation compatibility condition is applied between the frame anchors and surrounding soil.  
These assumptions provide a reasonable approximation for simulating frost heave effects in cold-region slope engineering scenarios.
## 1 Introduction  
Vertically structured Si quantum dot (QDs) solar cells implementing a Molybdenum (Mo) back contact layer have been proposed as a method to overcome the current crowding effects found in previous mesa-structured cells [1; 2; 3; 4]. As illustrated in Figure 1a, the drawback of a mesa-structure is the transport of lateral carriers across the thin resistive bottom layer to be collected by the cathode or anode. The resulting low current output has limited the application of this structure towards high efficiency photovoltaic devices as expected. On the contrary, the vertical structure shown in Figure 1b will overcome the current crowding problem by circumventing lateral current flow in the bottom layer. This requires employment of a conductive interlayer between the Si QDs solar cell, and the substrate to serve as the back contact. Apart from the expected improvement in current output, another benefit of the vertical structure is that it simplifies the fabrication process by removing the necessity of reactive ion etching (RIE) to create mesa-islands as previously needed.  
Molybdenum (Mo) is selected in this work for the aforementioned back contact interlayer, due to its high melting point and good electrical conductivity. The main investigation on Mo as metal contacts is focused on the effect of the deposition condition in CuInGaSe\({}_{2}\) (CIS) based solar cells detailed in previous reports; however, the annealing temperatures were all below 600 \({}^{\circ}\)C due to the limitation imposed by the soda-lime glass substrate used in these studies [5; 6; 7; 8; 9; 10; 11; 12]. However, Si QDs formation requires a high temperature annealing process up to 1100 \({}^{\circ}\)C, and thus the Mo thin films should still have good conductivity after such high temperature treatment. Our previous study showed that sputtered Mo thin films on fused silica substrates suffered severe degradation, due to the formation of cracks after annealing at 1100 \({}^{\circ}\)C [3; 4]. This was primarily due to the mismatch of the thermal expansion coefficient, which hindered the realization of vertically structured devices. Therefore, in this study, we replaced the fused silica with Si wafers, which have a thermal expansion coefficient close to the value of Mo [4]. Our work discusses the evolution of Mo properties, with respect to different annealing temperatures from 700 \({}^{\circ}\)C to 1100 \({}^{\circ}\)C on Si substrates.