esa-sceva/satcom-chunk-collection huggingface dataset:
## 1 Introduction
In this method, the pose information of non-cooperative space targets is directly output through end-to-end learning; that is, the image taken by the monocular sensor is input into the model, and the model can directly output the pose information of non-cooperative space targets without using the CAD model of the object. The algorithm uses EfficientNet as the backbone network for feature extraction and randomly selects two feature layers to input into the two pose estimation subnetworks of translation transformer and orientation transformer. The dual-channel network is used to learn translation information and orientation information, respectively, which effectively avoids the interaction between the two kinds of information. According to the characteristics of orientation information, a quaternion SoftMax-like activation function is designed to improve the accuracy of the satellite orientation information. Finally, experiments are performed on SPEED provided by ESA. The experimental results show that the proposed algorithm can successfully predict the satellite pose information, and the recognition efficiency is significantly improved compared with other methods. The main contributions of this paper are as follows:  
* An end-to-end learning non-cooperative space object pose estimation network is proposed to input the images taken with a monocular sensor into the model. The model directly outputs the pose information of the non-cooperative space objects, which can simplify the estimating process of pose information. * A dual-channel transformer non-cooperative space object pose estimation network is designed to innovatively apply transformer to the end-to-end learning satellite pose estimation task. The dual-channel network design successfully decouples the spatial translation information and orientation information of satellites. * A new quaternion SoftMax-like activation function is designed to make the model output according to the quaternion constraint so as to effectively improve the precision of orientation prediction. The paper is structured as follows: Section 2 presents our proposed dual-channel transformer model with a quaternion activation function. We provide a detailed description of the model architecture, including the design of the dual-channel mechanism and the quaternion activation function. Section 3 focuses on the experimental setup and results analysis. First, we analyze the data used in our experiments, including their characteristics and sources. Then, we introduce the evaluation metrics employed to assess the performance of the dual-channel transformer model. Finally, we present the results of the multiple ablation experiments conducted. Furthermore, we compare the performance of our model with that of other existing models. Section 4 focuses on drawing conclusions while summarizing the innovations and beneficial effects of our work.
###### Abstract
The concrete structure and reinforcement of railway sleepers can be damaged by temperature change, relative humidity, freeze-thaw of water and chemical deterioration [26]. Therefore, time-dependent behaviour is also affected by environmental conditions which can accelerate damage to railway sleepers [27]. Many studies have been carried out on fracture mechanics of concrete structures; however, very few of them have targeted railway sleepers [28]. [PERSON] et al. discussed possible causes of cracking of prestressed concrete sleepers [26]. Meanwhile, [PERSON] et al. presented experimental studies on crack propagation of prestressed concrete sleepers with single steel tendons subject to impact loads [29]. Further, [PERSON] et al. studied how the cracks in prestressed concrete sleepers influence track behaviour under static loading [17]. Finally, [PERSON] and [PERSON] investigated the fracture mechanics parameters of prestressed concrete sleepers [30]. These previous studies provided a general understanding of cracking behaviour in prestressed concrete sleepers and analysed the causes of cracking. The simulation methods performed are reviewed in order to find the best solution for \begin{table}
\begin{tabular}{l l c} \hline \hline
**Main Causes** & **Problems** & **Worldwide Response** \\ \hline \multirow{2}{*}{Lateral load} & Abrasion on rail-seat & 3.15 \\  & Shoulder/fastening system wear & 5.5 \\  & or fatigue & \\  & Cracking from dynamic loads & 5.21 \\ Vertical dynamic load & Derailment damage & 4.57 \\  & Cracking from centre binding & 5.36 \\ Manufacturing and & Tamping damage & 6.14 \\ maintenance defects & Others (e.g., manufactured defects) & 4.09 \\ Environmental considerations & Cracking from environmental or & 4.67 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Most critical causes of concrete sleeper failures (ranked from 1 to 8, with 8 being the most critical). cracking simulation. However, in their research, the effect of time-dependent behaviour has not been considered in the cracking behaviour of prestressed concrete sleepers. This paper aims to investigate the crack propagation of prestressed concrete sleepers at midspan. The effect of time-dependent behaviour on cracking is also presented. The finite element method constitutes a very useful tool to study the crack propagation in prestressed concrete sleepers. In this paper, a numerical study is rigorously executed to comprehensively assess the structural performance of prestressed concrete sleepers exposed to time-dependent behaviour. Emphasis is placed on the numerical analysis of fracture mechanics of prestressed concrete sleepers. The finite element sleeper model was developed and validated to simulate the cracking phenomenon at the midspan. The static capacity experiment of prestressed concrete sleepers conducted by [PERSON] [31] is used to validate the crack model.
Despite its simple construction it is robust and has a low maintenance costs. The double stream gas-puff target source represents a versatile alternative to perform experiments in small academic laboratories without the necessity to access to large-scale facilities, and can be regarded as complementary diagnostic tools for high spatial resolution imaging, obtaining additional information about the objects not directly available using other microscopy techniques. The laser-plasma source based on a double stream gas-puff target was successfully employed, thus far, for different applications [50], such as for shadowgraphy systems [51], radiography [52], radiobiology [53], photoionization [54], metrology [55], plasma channel studies [56] and, as will be shown extensively, imaging experiments [57; 58; 59]. Full field microscopy based on gas-puff target sources and diffractive optics, such as FZPs, represents a good way to perform experiments on small scales, obtaining a sub-100 nm resolution [58; 60]. Moreover, it is based on a compact and accessible setup, opening the possibility for wider multidisciplinary collaboration with biologists, chemists, and scientists from other disciplines. Despite the employed FZPs allow achieving a sub-10 nm spatial resolution [61], it is still challenging to find a necessary compromise between the exposure time and the size and complexity of the microscope's architecture [42]. Several parameters can be improved to overcome this trade-off, such as obtaining high photon flux and repetition rate minimizing the debris production, increasing the charge-coupled device (CCD) resolution [62], etc. The gas-puff target source can also be successfully employed for the so-called soft X-rays contact microscopy, enabling to achieve a good contrast image of wet biological samples up to several \(\upmu\)m thick [63], and avoiding complex and required invasive preparation procedures of the samples, such as the dehydration process, necessary for scanning electron microscopy and the immunofluorescence labeling method needed for fluorescent microscopy [64; 65]. Ultra-short SXR pulse radiations generated by laser-produced plasma sources make it possible to acquire 10 nm resolution images of living biological samples before the occurrence of the sample damage [66], employing the natural contrast of the \"water window\" spectral range [63]. The double stream gas-puff target represents an excellent source to acquire contrast images in this wavelength range and can be successfully employed for contact microscopy of biological samples, achieving a half-pitch spatial resolution of about 80 nm [67]. The following review is directed toward the development of microscopes based on gas-puff target sources emitting in the EUV and SXR spectral range, presenting several biological imaged samples. It will be shown that such microscopes allow achieving a sub-100 nm spatial resolution, superior to the classical visible light microscopes. The development of such microscopes provides the opportunity for imaging of various samples and for identifying additional information about them, which cannot be directly observed using other imaging methods.
## 1 Introduction
Gravity UPHES, operating as PHES with the difference that the lower reservoir is located underground, are relatively costly in investment because, to offer a sufficient density of energy storage, they require to use deep caverns or deep disaffected mines located at depth of 300-1200 m as lower reservoirs. Salt domes are geographically scarce, must be of sufficient depth and are not suitable to contain fresh water. A few hydro-pneumatic UPHES were presented instead, using conventional hydroelectric pumps and turbines, where the difference of elevation is replaced by a piston of compressed air in the upper part of a cavern, each 0.1 MPa of pressure providing a 10-meter head. In 1986, SHELL Internationale Research Maatschappji B.V of the Netherlands filed a European Patent at EPO for such a UPHES [11]. [PERSON] et al. studied in 2013 a model of compressed-air pumped-hydro in adiabatic as well as in isothermal processes with the prospect of burying pressurized reservoirs underground and of overcoming some efficiency limitations of CAES by the use of hydro pumps and turbine [12]. Unfortunately, air warms-up with compression during electricity charge and cools-down with decompression during electricity discharge. RTE is therefore significantly reduced due to these irreversibilities. However, as reported by [PERSON] et al., it must be added that, at the Oak Ridge National Laboratory, a small-size aerial prototype of hydro-pneumatic energy storage was able to reach RTE ranging from 66% to 82% thanks to the innovative heating and cooling of the air with water spray and thanks to the utilization of waste heat [13]. In all cases, unlined natural caverns or unlined mines must also be located deeply underground to maintain the tightness of compressed air through a hydrostatic containment by ground water (i.e., a 1000 m depth to contain a pressure of 10 MPa). For both types of UPHES, gravity-type as well as hydro-pneumatic-type, the geographic availability of natural caverns or disaffected mines, close to actual locations of electricity production, electricity consumption or close to power transmission networks, is also overly limited. Several improvements are therefore needed so that UPHES can bring significant value for the storage of solar and wind energy. Based on three directions of innovation, the purpose of this early conceptual publication is to address the relevance of a novel type of UPHES for the bulk storage of intermittent electricity by disclosing its leading principles. A hybrid solution of low Capex cost (20 USD per kWh referring to the sole electricity capacity), targeting a medium-high RTE (60%-70%) is proposed, making use of the reliability and efficiency of pumped-hydro equipment, of the emerging technology of shallow LRC (Lined Rock Cavern), of the slow displacement of a CO\({}_{2}\)-water interface and of the low Capex cost of large atmospheric thermal storages.
## 3 Prototyping and Proposed Implementation
### Designing Intelligent Algorithms to Optimize the Development of a Project-Coestim
Things like response time under stressful conditions are considered in this step, see Table 1.  
Database performance testing was also performed using Pgbench which is a simple performance testing program for PostgreSQL databases. Runs the same sequence of SQL commands repeatedly, possibly across multiple concurrent database sessions, and then calculates the average transaction rate (transactions per second). A test scenario was prepared: 10 clients (concurrent sessions) distributed over 2 threads were considered and tests with a different number of transactions were performed for each client. Example for database connection:  
pgbench - U Postgres - p 5433 - c 10 - j 2 - t 10 Coestim  
-U database user; p-port server; c-number of customers; j-number of threads; t- number of transactions per customer. Graphical representation of the simulation order processing process (TPS) is shown in Figure 11.  
An Apache test tool was also used to analyze and measure the performance of applications, various software services, and products. Optimizations have been made regarding the performance of the database, bringing a series of changes:  
- Given that the population of the database with articles is conducted by taking them from the systems of suppliers, to identify the article easier for the supplier added a text column to the entity \"SupplierItem\" containing a link to the article from the supplier. In the entity, \"SupplierFeedOutModule\" the column \"CustomItemBaseMapping\" is deleted because during the implementation the column \"ItemBaseMapping\" proved to be sufficient to save the mapping of an article to a chosen file format. A column has been added containing a code for both services and resources to make them easier to identify. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Transaction per Client**} & \multirow{2}{*}{**Processed Transactions**} & **Tps (Includes Database** & **Tps (Excludes Database** & \\  & & **Connection Time)** & **Connection Time)** \\ \hline
10 & 100 & 293.59 & 346.15 \\
20 & 200 & 724.76 & 860.19 \\
30 & 300 & 1012.95 & 1186.24 \\
50 & 500 & 1567.23 & 1807.44 \\
80 & 800 & 1815.44 & 2062.7  
Price and quantity columns were renamed and the data type was changed to \"EstimateItem\" and \"ProjectExecutionItem\", according to their name and type in \"SupplierItemPrice\". The \"SuperServiceResource\" entity has been filled in with the necessary columns to specify the number of hours required for a resource and to indicate whether it is on the entire super-service. There were also changes in the data type for the quantity column in the entities \"ServiceResource\" and \"EstimateServiceResource\" to accept real values.
## 6 Experimental Results and Discussion
### Comparisons of the 1-D CNN Model and Other Typical Methods  
In order to verify the performance of the 1-D CNN single-measuring point model of reciprocating compressor gas valve fault diagnosis, the test set was trained to optimize the model parameters. Next, the 1-D CNN single-measuring and three other models were applied to compare their accuracy, as shown in Table 4.  
Three classic models were used for comparison, including the SVM model with power spectrum energy, BP model with power spectrum energy, and wavelet packet energy. Next, 78 working samples with 4 states (normal valve disc, broken valve disc, broken spring, notched valve disc) were randomly selected and each sample length was 1024 data points as input for the above model. Furthermore, 40 samples of each working condition were randomly selected to constitute the fault training set (160 in total) for model training and samples (152 in total) to constitute the test set of the model.  
Table 4 compares the diagnostic effects of the four models on the test set. As can be seen, the 1-D CNN single-measuring point model has the highest recognition rate with an accuracy of 100%, which can effectively diagnose the reciprocating compressor valve failure.
# Secure On-Off Transmission in UAV Relay-Assisted mmWave Networks
## Appendix B Proof of Lemma 2  
First, the probability that the selected UAV relay is LOS is derived as  
\[\begin{split} A_{L}&=\Pr\left(C_{L}d_{L}^{-\alpha_{L} }>C_{N}d_{N}^{-\alpha_{N}}\right)\\ &=\int_{0}^{Q}\bar{F}_{r_{N}}\left(\max\left(0,\sqrt{\left(\frac{C _{N}}{C_{L}}\right)^{\frac{2}{R_{N}}}(r^{2}+H^{2})^{\frac{\alpha_{L}}{R_{N}}}- H^{2}}\right)\right)f_{r_{L}}\left(r\right)dy\\ &=\sum\limits_{i=0}^{T}w_{i}^{(r)}e^{v_{N}\left(\max\left(0, \sqrt{\left(\frac{C_{N}}{C_{L}}\right)^{\frac{2}{R_{N}}}(r_{i}^{2}+H^{2})^{ \frac{\alpha_{L}}{R_{N}}}-H^{2}}\right)\right)}f_{r_{L}}\left(r_{i}\right).\end{split} \tag{10}\]  
Accordingly, we can easily obtain the \(A_{N}=1-A_{L}\), which is the probability that the nearest NLOS UAV relay is selected.  
Giving that the selected UAV relay is LOS, we then derive the CCDF of the horizontal distance from \(D\) to the nearest LOS UAV relay, and its derivations are written as  
\[\begin{split}\bar{G}_{r_{L}}\left(r\right)&=\Pr \left(r_{L}>r\left|r_{N}>\max\left(0,\sqrt{\left(\frac{C_{N}}{C_{L}}\right)^{ \frac{2}{R_{N}}}(r^{2}+H^{2})^{\frac{\alpha_{L}}{R_{N}}}-H^{2}}\right)\right. \right)\\ &=\frac{\int_{r_{L}}^{\infty}\Pr\left(r_{N}>\max\left(0,\sqrt{ \left(\frac{C_{N}}{C_{L}}\right)^{\frac{2}{R_{N}}}(z^{2}+H^{2})^{\frac{\alpha_ {L}}{R_{N}}}-H^{2}}\right)|r_{L}>z\right)f_{r_{L}}(z)dz}{A_{L}}.\end{split} \tag{11}\]  
Finally, we can obtain the PDF \(g_{r_{L}}\) as (6) by using the derivation \(g_{r_{L}}\left(y\right)=-\frac{d\bar{G}_{r_{L}}\left(y\right)}{dy}\).
## 4 Security Analysis and Discussion
### Resource Efficiency Evaluation  
When evaluating the practical viability of quantum key agreement protocols, computational efficiency represents a deterministic parameter, particularly critical in resource constrained healthcare systems. The academic community has established a standardized efficiency evaluation methodology [24], mathematically expressed as:  
\[\eta_{1}=\frac{S}{Q+C}\]  
where \(S\) denotes the quantity of securely shared classical information bits, \(Q\) represents the quantum resources consumed (quantified in qubits), and \(C\) represents the number of classical bits used, excluding those required for the announcement of decoy photon positions and measurement bases. This efficiency metric provides an objective foundation for performance comparison across various protocols by comprehensively examining the relationship between protocol output and resource utilization. However, \(\eta_{2}=\frac{S}{Q}\) is employed to quantify qubit efficiency [25], whereas \(\eta_{1}\) is utilized to assess the efficiency of quantum communication protocols [24].  
Our quantum key agreement protocol, designed specifically for secure communication between the Patient's Device (PD) and Healthcare Provider (HP), aims to establish a cryptographic key of 2n bits. Upon successful completion, the protocol generates 2n bits of securely shared information while consuming quantum resources that include 4n qubits for initial quantum state preparation (2n by PD and 2n by HP) and an additional 4n qubits for decoy states utilized in the public key exchange phase (2n by PD and 2n by HP), resulting in an aggregate consumption of 8n qubits throughout the protocol execution. The classical communication requirements encompass no classical bits for confidential parameter transmission.  
When these operational parameters are substituted into the standardized efficiency formula, we obtain \(\eta_{1}=\frac{2\eta}{8n+0}=\frac{1}{4}\) and \(\eta_{2}=\frac{2\eta}{8n}=\frac{1}{4}\) demonstrating that our protocol achieves a theoretical efficiency level of approximately 25%.
## 2 Numerical Model
### Model Details
For the sake of convenience, a mesh size of 0.25 m was used in the area around the fire (50 m downstream and 50 m upstream), while, for the rest of the tunnel, a mesh size of 0.5 m was used, as shown in Figure 3. The total number of cells was 1,355,200. The mean value of errors of the U velocity for the coarse and medium meshes was approximately 14%, for the medium and fine mesh it was 5%, and for the medium and final mesh used it was 4%. For the CO concentrations, the mean error values for the coarse and medium mesh was 16%, for the medium and fine mesh was 8%, and for the medium and final mesh was 6% The mesh resolution, which was proposed in the UNSRC and EPRI directive, was used in many other tunnel fire simulations such as [35; 36; 37]. The work for the numerical simulation was conducted in the National HPC facility--ARIS, with computational time granted from the National Infrastructures for Research and Technology S.A. (GRNET S.A.). For each scenario, 22 cores and 56 GB of memory were used, and the typical time taken to complete each computation was 24 h.
# A Security-Oriented Data-Sharing Scheme Based on Blockchain
## 4 Experiment and Analysis
### NFT Time Overhead  
In our proposed scheme, the NFT, which serves as a proof of ownership for shared content, is stored on the blockchain with its sharing history recorded via smart contracts. The efficiency of the NFT minting and querying processes significantly impacts the performance of this scheme. To measure the overhead of NFT operations, we performed a series of one hundred experiments for both minting and querying. Averaging the results ensured the reliability of our findings. The outcomes of these experiments are detailed in Figures 7-9.  
Figures 7 and \(8\) present results from 100 experimental trials, showing that the ownership proof NFT in our scheme exhibits consistent time overhead for both minting and querying processes, with negligible variation. Figure 9 illustrates that the average duration for NFT operations is approximately two seconds, indicating high efficiency. These findings confirm that our scheme meets the criteria for rapid response times in secure data sharing, ensuring that users can access the required information promptly, and supporting a variety of real-time applications.
# A Two-Stage Registration Strategy for Thermal-Visible Images in Substations
## 2 Proposed Methodology
### Second Registration
#### 2.2.1 Feature Point Extraction  
The stable and efficient extraction of feature points in the image is very important for the follow-up work of image registration. The images from the monitoring camera are often not clear enough, the details are lost, and the features are unstable, which will lead to an inability to extract enough effective feature points. In view of the above problems, SIFT [24], SURF [31] and Harris [35] are usually used as feature point detectors. Among these, SIFT can still provide effective detection results for images of poor quality. Compared with SIFT, SURF has better robustness to outliers and noise in the image, and its calculation speed is also significantly improved. However, the above two methods still have the problem of being sensitive to pixel intensity, and they are both designed for single-mode image registration. However, in multi-source image pairs, such as the thermal-visible image studied in this paper, many detailed features existing in the visible image do not appear in the thermal image, which will lead to the above methods being unable detect enough effective feature information in multi-source images. In contrast, the Harris detector is more sensitive to diagonal structure features, can effectively locate common features, even in multi-modal images, and has higher repeatability for the detected feature points. Therefore, the Harris detector was chosen to extract the features from the thermal visible image.