esa-sceva/satcom-chunk-collection huggingface dataset:
# Fault Location and Restoration of Microgrids via Particle Swarm Optimization
## 5 Numerical Results and Discussions
### Description of the Sample System and Simulation Scenarios  
The MG sample system was modified on the basis of the IEEE 37-bus test system (Figure 5). Five new tie lines and switches were added as follows. S36 was installed between buses 701 and 722. S37 was installed between buses 735 and 741. S38 was installed between buses 727 and 732. S39 was installed between buses 725 and 731. S40 was installed between buses 712 and 740. In addition, the DGs were connected at buses 724, 731, and 740. The parameters of the tie switches and lines are shown in Table 1. The power outputs of the DG at buses 724, 731, and 740 are 595, 460, and 150 kW, respectively.  
Figure 4: Proposed service restoration algorithm of the MG.  
The simulation scenarios are presented in Table 2, and the scenarios are explained as follows.  
* Scenario 1: A single-point fault in the line segment is assumed between buses 702 and 703. This fault is used to simulate a situation in which most of the downstream areas of the MG are affected due to the fault that occurred in the upstream of the MG.
* Scenario 2: A double-point fault in a line segment is assumed: one point is between buses 702 and 703, and the other point is between buses 727 and 703. This fault is used to simulate multiple power outages in downstream areas. Multiple tie switches and lines must be operated at the same time for service restoration.
* Scenario 3: A triple-point fault in the line segment is assumed. The multiple fault points are between buses 702 and 703, buses 727 and 703, and buses 710 and 734. This fault is used to simulate power generation less than the load demand in the downstream islanded area. Load shedding is required for this situation.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Switch No.** & **From Bus** & **To Bus** & **Length(m)** & **Voltage** & **Phase** \\ \hline S36 & 701 & 722 & 91.44 & 4.8 kV & ABC \\ S37 & 741 & 735 & 152.40 & 4.8 kV & ABC \\ S38 & 727 & 732 & 60.96 & 4.8 kV & ABC \\ S39 & 725 & 731 & 243.84 & 4.8 kV & ABC \\ S40 & 712 & 740 & 457.20 & 4.8 kV & ABC \\ \hline \hline \end{tabular}
\end{table}
Table 1: Parameters of tie switches and lines.  
Figure 5: Single-line diagram of the sample system.  
In this study, a co-analysis and simulation platform was established (Figure 6). The sample system was built in OpenDSS [31] and MATLAB: the value of the measured voltage of the sample system was obtained by OpenDSS, and the proposed fault location, service restoration, and power flow algorithms were coded in MATLAB.
# Nonlinear Optimization and Adaptive Heuristics for Solving Irregular Object Packing Problems
## 4 General Circle Packings  
### Problem Statement  
The general circle packing (GCP) problem discussed here is defined as follows. Given \(N\) (in principle, arbitrary size) circles with radii \(r_{i}\) for \(i=1,\ldots,\ N\), find the minimum radius \(r_{0}\) of the circular container that contains these \(N\) circles in a non-overlapping arrangement. Assuming that the container is centered at the origin, we introduce the decision variables \(\left(x_{i},y_{i}\right)\) for the center of circle \(i\), in addition to \(r_{0}\). Denote by \(e_{ij}=\sqrt{\left(x_{i}-x_{j}\right)^{2}+\left(y_{i}-y_{j}\right)^{2}}\) the Euclidean distance between the centers of circles \(i\) and \(j\). Then, a possible model formulation is  
GCP:  
Minimize \(r_{0}\)  
\(x_{i}^{2}+y_{i}^{2}\leq\left(r_{0}-r_{i}\right)^{2}\) for \(i=1,\ldots,N\)  
\(\left(r_{i}+r_{j}\right)^{2}\leq e_{ij}^{2}\) for \(i,j=1,\ldots,N,i<j\).  
The GCP model has \(2N+1\) decision variables, \(N\) convex constraints (see (4)), and \(N(N-1)/2\) nonconvex constraints (see (5)). The GCP model is an example of a _scalable_ object-packing model class: for a given \(N\) and given sequence of radii \(r_{i}\) for \(i=1,\ldots,\ N\), we can directly create the corresponding model instance.
# Link Pruning for Community Detection in Social Networks
## 1 Introduction
* We notice a different pattern between the attributes of links within a cluster (i.e., internal links) and those of links belonging to different clusters (i.e., external links). * We develop a new community detection algorithm that removes less important links according to the different patterns of link attributes. * We theoretically prove that link pruning effectively detects enhanced communities using a random graph model with planted clusters. * We empirically show that the proposed algorithm achieves higher accuracy than the existing algorithms, especially when the pruning rate increases.
# Evaluating Uncertainties in Marine Biogeochemical Models: Benchmarking Aerosol Precursors
## 1 Introduction
### The Marine Atmospheric and Aerosol Environment  
The marine boundary layer (MBL) is that part of the atmosphere closest to the ocean, extending from the ocean surface up to 100-1000 m above sea level. Within this subset of the planetary surface layer, ocean and atmosphere exchange heat and matter through turbulent fluid mechanical transport [37]. Air-sea interactions are dynamically driven, as in the case of wind shear at the ocean surface, or thermodynamically driven, with respect to buoyancy. These interactions initiate the formation of primary sea salt and secondary non-sea-salt aerosols that could serve as nucleating agents. Cloud supersaturations in the order of 0.2% to 0.3% or even less are capable of activating aerosol in the accumulation mode (0.1-1.0 \(\upmu\)m), forming the cloud droplets at the global scale and imparting their strong effects on reflectivity [27]. An absence of anthropogenic and terrestrial aerosols over the far reaches of the open ocean leaves a clean marine environment, in which natural precursors serve as cloud condensation nuclei (CCN). Ultimately, they control the formation of low-level stratus and stratocumulus clouds [38]. Albedo modification is thus partly driven by natural processes.  
The study of biogeochemical cycling in the boundary layer regime has advanced steadily across the regional and global environment over the past few decades, bringing with it an enhanced appreciation for the complexity of marine climate feedbacks. Novel techniques for gathering field datasets come online continually [15; 34], reinforcing ever-improving model structures in a positive cycle [5; 6]. Innovative upper ocean biogeochemical mechanism designs have been particularly effective contributors. Simulations now extend from the original, simple foodweb concept to intricate processing that may require hundreds of state variables and multiple trace elemental cycles [39; 40; 41; 42; 43; 44]. In some cases, detailed trace gas and aerosol precursor modules are now included [4; 5; 45]. Increases in model complexity come with a downside, however: multiple layers of uncertainty are introduced into the analysis, and there are still more questions to be answered in terms of parameterizing marine aerosols in ESMs.  
As the frontiers of computation meet up with modern analytical techniques (largely chemical and biological), there will be the need to apply continually updated constraints that are relative to observations at all scales. Disparities between model results and field data often raise the most critical questions, regarding for example the level of objective validation that has been attained, or the very reliability of current ESM structures [11; 46]. To reduce uncertainties and improve model development, it is critical to validate and skill-test the surface ocean biogeochemistry that is now being rapidly incorporated into contemporary ESMs. We must continually reinvent our understanding of their fundamental capabilities [47].
## 6 Conclusions  
In this paper, we present a system model for energy harvesting and information transmission in wireless communication, which utilizes two protocols in the energy-harvesting part of the downlink, namely the HHT and HDT protocols. Our main objective is to compare and analyze the system reliability, packet timeout probability, and outage probability of these two protocols to evaluate their performance. Moreover, we simulate the proposed system using the Monte Carlo simulation method based on the channel state. Our simulation results indicate that the HHT protocol outperforms the HDT protocol in terms of system reliability, packet timeout probability, and outage probability. Specifically, the HHT protocol demonstrates higher system reliability and lower packet timeout and outage probabilities compared to the HDT protocol under similar conditions. Therefore, the HHT protocol with MRC technology is considered optimal for our proposed system.  
In our future work, we plan to apply our research results to artificial hearts and other medical fields, which may lead to unexpected benefits. This could potentially alleviate the current limitations for artificial heart recipients who are hesitant to venture far from urban areas due to concerns about timely energy replenishment as well as improve their quality of life. Additionally, the effective utilization of RF energy harvesting could bring new changes to our 6G smart era and provide a new way for people to experience the relative abundance of energy in their daily lives.  
Conceptualization, K.L. and Z.Z.; methodology, K.L.; software, K.L.; validation, K.L. and Z.Z.; formal analysis, K.L.; investigation, K.L.; resources, Z.Z.; data curation, K.L.; writing--original draft preparation, K.L.; writing--review and editing, Z.Z.; visualization, K.L.; supervision, Z.Z.; project administration, Z.Z. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
**Data Availability Statement:** Not applicable, the study does not report any data.  
**Conflicts of Interest:** The authors declare no conflict of interest.
###### Abstract  
Our study focuses on methodological comparison of plankton community composition in relation to ecological monitoring and assessment with data sampling. Recently, along with the advancement of monitoring techniques, metabarcoding has been widely used in the context of environmental DNA (eDNA). We examine the applicability of eDNA metabarcoding for effective monitoring and assessment of community composition, compared with conventional observation using microscopic identification in a coastal ecosystem, Gwangynag Bay in South Korea. Our analysis is based primarily on two surveys at a total of 15 study sites in early and late summer (June and September) of the year 2018. The results of our study demonstrate the similarity and dissimilarity of biological communities in composition, richness and diversity between eDNA metabarcoding and conventional microscopic identification. It is found that, overall, eDNA metabarcoding appears to provide a wider variety of species composition, while conventional microscopic identification depicts more distinct plankton communities in sites. Finally, we suggest that eDNA metabarcoding is a practically useful method and can be potentially considered as a valuable alternative for biological monitoring and diversity assessments.  
coastal ecosystem; eDNA; metabarcoding; microscopy; monitoring and assessment +
Footnote †: journal: Applied Sciences
# Evolution of V2X Communication and Integration of Blockchain for Security Enhancements
## 7 Open Issues and Future Research Directions
### Security and Privacy Issues  
The vehicle platooning and collaborative control are important aspects of future autonomous vehicles. However, there are security issues and vulnerabilities that exist in application, and networks layers in autonomous platooning, such as message spoofing, DoS, burst transmission, etc. These cyber security issues can be resolved by integrating synchronisation-based control techniques that implements a decentralized detection method to cope with several malicious activities [96; 97].  
Even though blockchain is considered as a secured distributed ledger, there are certain privacy and security issues in an integrated blockchain. One of the weaknesses is 51% attack vulnerabilities where the attackers modify transaction orders, disrupt mining operations, or trigger double-spending attacks that hamper the blockchain network [98]. Moreover, an attack on a smart contract might result in the leakage of private information about the vehicles, or system logic alterations. Some of the examples of security flaws in integrated blockchain in 5G-based MEC are time-stamping dependency, mismanaged exceptions, and re-entry attacks on smart contracts. Another issue is that anonymous nodes can act as a legitimate network member and perform edge data processing, but they might accesspersonal information of the vehicles that leads to a privacy issue. While blockchain uses encryption and digital signature to maintain transactions, recent analytical results [99] reveal that transactions can be disclosed during blockchain formation showing that blockchain data security is not very robust in practice. In addition, hackers can exploit smart contracts for illicit activities, causing sensitive data leaks, e.g., cryptographic keys.  
Some research results help to address security issues to enhance the overall performance of the integrated ecosystem, such as SmartPool [100], which implements a mining pool to improve transaction verification that overcomes 51% attack vulnerability. More recently, researchers presented an effective security assessment for examining and preventing potential threats, which ensures trustworthy smart contract execution under blockchain [101; 102].
# RSVQ-Diffusion Model for Text-to-Remote-Sensing Image Generation
## 4 Experimental Results and Analysis
### Ablation Experiments
The second to fifth columns, respectively, show the generated images from the original model, the model with spatial positional encoding, the model with local attention mechanism, and the RSVQ-Diffusion model. Each row represents the images generated by different models given the same input text. VQ-Diffusion model shows deformed overpasses, missing buildings, and blurred details. The VQ-Diffusion_SP model generates features that match the text description, but the overpass appears deformed. The VQ-Diffusion_LMA model produces a reasonably shaped overpass but lacks the semantic information of the \"river\". The RSVQ-Diffusion model accurately places the overpass, with the buildings and trees reasonably structured. The river detail in the upper right corner is slightly blurred. For group (c), the VQ-Diffusion model generates distorted details; the VQ-Diffusion_SP model's mountain textures are blurred, and the VQ-Diffusion_LMA model generates mountains with reasonable colors but with a chaotic distribution. The RSVQ-Diffusion model produces mountains with continuous textures, naturally transitioning to the brown exposed ground, with reasonable spatial structure. For group (d), the RSVQ-Diffusion model generates farmland with semi-regular geometric shapes, better color transitions, and better spatial distribution compared to the original model's generated images. From groups (e) to (h), the images generated by the VQ-Diffusion model exhibit target deformations, twisted spatial structures, and unreasonable color distributions, failing to reflect the corresponding textual information. The VQ-Diffusion_SP and VQ-Diffusion_LMA models generate images that reflect improvements in spatial structure and local details. The RSVQ-Diffusion model produces images with complete lake structures and clear boundaries, factory buildings that align with real target scene distributions and are neatly arranged, realistic tree colors, and well-organized oil tanks in the factories. The overall image quality generated by the RSVQ-Diffusion model surpasses the other three models. Based on the evaluation metrics from the ablation experiments and the generated images, it is evident that the image generation capabilities of the RSVQ-Diffusion model significantly surpass those of the VQ-Diffusion model. The two improved versions, VQ-Diffusion_SP and VQ-Diffusion_LMA, each demonstrate visual enhancements that align with the principles of their respective modules. Although there are still differences between the images generated by the RSVQ-Diffusion model and real images, the generated images from the improved model show clear target details and spatial consistency, making the visuals more reasonable. They effectively reflect the scenes described in the text.
###### Abstract  
Nitrogen-doped graphene (NDG) and mixed metal oxides have been attracting much attention as the combination of these materials resulted in enhanced electrochemical properties. In this study, a composite of nitrogen-doped graphene/manganese oxide/iron oxide (NDG/Mn3O4/Fe3O4) for a supercapacitor was prepared through the hydrothermal method, followed by freeze-drying. Field emission scanning electron microscopy (FESEM) images revealed that the NDG/Mn3O4/Fe3O4 composite displayed wrinkled-like sheets morphology with Mn3O4 and Fe3O4 particles attached on the surface of NDG. The presence of NDG, Mn3O4, and Fe3O4 was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The electrochemical studies revealed that the NDG/Mn3O4/Fe3O4 composite exhibited the highest specific capacitance (158.46 F/g) compared to NDG/Fe3O4 (130.41 F/g), NDG/Mn3O4 (147.55 F/g), and NDG (74.35 F/g) in 1 M Na2 SO4 at a scan rate of 50 mV/s due to the synergistic effect between bimetallic oxides, which provide richer redox reaction and high conductivity. The galvanostatic charge discharge (GCD) result demonstrated that, at a current density of 0.5 A/g, the discharging time of NDG/Mn3O4/Fe3O4 is the longest compared to NDG/Mn3O4 and NDG/Fe3O4, indicating that it had the largest charge storage capacity. NDG/Mn3O4/Fe3O4 also exhibited the smallest resistance of charge transfer (\(R_{\text{ct}}\)) value (1.35 \(\Omega\)), showing its excellent charge transfer behavior at the interface region and good cyclic stability by manifesting a capacity retention of 100.4%, even after 5000 cycles.  
supercapacitor; mixed metal oxides; N-doped graphene +
Footnote †: journal: Applied Physics Letters
## 4 Discussion
### Possible Applications of Food Processing By-Products as Dust Suppressants at Mine Sites
#### 4.3.2 Financial Considerations  
The application of food processing by-products as dust suppressants appears to have financial benefits compared to commercially available biopolymers. By-products from the food industry are usually inexpensive, generated in high volumes, and readily available [13; 14; 15]. Chicory unmasses, for example, is priced at less than 100 USD/t (data according to the supplier). By contrast, the biopolymer xanthan gum, extensively investigated for soil stabilization and wind erosion control in previous studies, ranges in price from 1500 to 4000 USD/t [41; 50]. However, growing demand for biopolymers and the associated increase in production volume are expected to reduce biopolymer prices in the future [41; 50; 51].  
Specific emphasis should be paid to equipment operating costs, which can frequently escalate the total costs of dust suppression [52]. Here, significant cost drivers include the suppressants' durability and their related re-application intervals required to sustain a sufficient level of dust control [46]. Compared to biopolymers, tested biomaterials will likely need shorter re-application intervals because rainfall may leach them from surface substrates more easily. Some biopolymers have thermal-gelation properties, such as gellan gum or agar gum, which only dissolve entirely in hot water [53]. Likewise, proteins (e.g., casein) with lower hydrophilicity probably provide higher resistance to rainfall and subsequent leaching [54]. However, a reliable cost-effectiveness assessment requires further research, considering biomaterials durability, application intervals and application rates. One possible approach to progress this knowledge would be the economic evaluation model developed by [PERSON] and [PERSON] [46], which enables the costing of the establishment, application and maintenance activities associated with the use of dust suppressants.
# Clutter-Masked Waveform Design for LPI/LPD Radarcom Signal Encoding
## 2 RSE Approach to Signal Design  
We use the OFDM modulation scheme to create either pulsed or continuous wave (CW) radarcom sampled signal, with samples \(s_{n}\):  
\[s_{n}=\frac{1}{2L+1}\sum_{m=1}^{2L+1}S(m)\cdot e^{|2\pi\frac{(m-1)(m-1)}{2L+1}}, \tag{1}\]  
where \(L\) is the total number of OFDM sub-carriers and \(S(m)\) is an amplitude coefficient of the \(m^{\text{th}}\) OFDM sub-carrier. These amplitude coefficients are proposed to be drawn from a random process with a probability density function (PDF) known to all authorized platforms.  
In [5], we selected Weibull-distributed random process with probability density function (PDF)\(f(x;\lambda,k)\), where \(\lambda\) is the scale parameter and \(k\) is the shape parameter. Assuming that the shape parameter \(k\) is selected arbitrarily and is known to the authorized platforms only, we proposed to encode communication data using the scale parameter \(\lambda\). For simplicity, we formulate that correctly recovering an estimate of \(\lambda\) by an authorized receiver achieves our goal of the communication data reception. An authorized receiver can perform this estimation using a simple expression [5; 17]:  
\[\hat{\lambda}=\frac{E\big{[}\hat{S}\big{]}}{\Gamma\Big{(}1+\frac{1}{k}\Big{)}}, \tag{2}\]  
where \(E\big{[}\hat{S}\big{]}\) is mathematical expectation of the vector \(\hat{S}\) containing estimates of the received signal's OFDM sub-carrier amplitudes, and \(\Gamma\) is the gamma function. In contrast, an unauthorized interceptor without the knowledge of \(k\) will need to perform estimation of that parameter first, which requires solving a non-linear equation that is highly susceptible to disturbances, such as additive noise:  
\[\hat{k}^{-1}=\frac{\sum\limits_{m=1}^{2L+1}\big{(}\hat{S}(m)\big{)}^{k}\ln \big{(}\hat{S}(m)\big{)}}{\sum\limits_{m=1}^{2L+1}\big{(}\hat{S}(m)\big{)}^{k}} -\frac{1}{2L+1}\sum\limits_{m=1}^{2L+1}\ln\big{(}\hat{S}(m)\big{)}, \tag{3}\]  
where \(\hat{S}(m)\) is the estimate of the \(m^{\text{th}}\) OFDM sub-carrier amplitude. We showed in [18] that an unauthorized interceptor would need signal-to-noise ratio (SNR) of intercepts to be above +20 dB to achieve acceptable accuracy in estimating \(k\)--thus reconstructing the data.  
Therefore, the RSE scheme is based upon using one of the parameters of a PDF for encoding information, and another parameter (or parameters) as a \"key\" with which the data can be reconstructed. The same signal that is generated in this fashion can be used for radar sensing. This approach is different from radar-embedded communications, as well as from RF tag-based one-way communications enabled by using radar beam energy.  
The security of this scheme can be further enhanced if in place of an arbitrary distribution an actual local clutter model was used, which is the focus of the next sections.