esa-sceva/satcom-chunk-collection huggingface dataset:
# Study on Mechanical Properties of Modified Polyurethane Concrete at Different Temperatures
## 3 Experimental Results and Discussion
### Axial Compressive Strength  
The value of the axial compressive strength (\(f_{\rm c,t}\)) was calculated in Equation (1). Figure 15 shows the axial compressive strength of modified polyurethane concrete at different temperatures. With the temperature increasing, the axial compressive strength of modified polyurethane concrete decreases obviously. At 15, 40 and 60 \({}^{\circ}\)C, the axial compressive strength decreases by 25.0%, 49.7% and 73.4%, respectively. With the temperature increasing, there is a great difference in the decline range of the axial compressive strength and cubic compressive strength, which causes a difference in the ratio of axial compressive strength and cubic compressive strength (\(f_{\rm c,t}/f_{\rm c}\)u). As shown in Figure 16, the ratio is between 0.8 and 1. The average value of the ratio of modified polyurethane concrete is about 0.89, which is obviously greater than the ratio of ordinary concrete.  
Figure 14: Relationship between splitting tensile strength and temperature.  
Figure 15: Relationship between prism compressive strength and temperature.  
Considering the influence of temperature, the temperature parameter is introduced. Using the data in Figure 15, the calculation expression for axial compressive strength and temperature is obtained by regression analysis, as follows:  
\[\frac{f_{\rm c,t}}{f_{\rm c,T}}=-0.023(\frac{t}{T_{0}})^{3}+0.153(\frac{t}{T_{0} })^{2}-0.489\frac{t}{T_{0}}+1.360 \tag{3}\]  
where \(t\) is the environmental temperature, the indoor temperature is \(T_{0}\) = 15 \({}^{\circ}\)C, and \(f_{\rm c,t}\) and \(f_{\rm c,T}\) are the axial compressive strength of modified polyurethane concrete at temperature \(t\) and temperature \(T_{0}\). \(R^{2}\) is the correlation coefficient, and \(R^{2}\) = 0.99.
# Broadcast Ephemeris with Centimetric Accuracy: Test Results for GPS, Galileo, Beidou and Glonass
## 7 Discussion
In the SSR concept ([[https://www.igscb.org/wp-content/uploads/2020/10/igs_ssr_-v1_00_20201005.pdf](https://www.igscb.org/wp-content/uploads/2020/10/igs_ssr_-v1_00_20201005.pdf)]([https://www.igscb.org/wp-content/uploads/2020/10/igs_ssr_-v1_00_20201005.pdf](https://www.igscb.org/wp-content/uploads/2020/10/igs_ssr_-v1_00_20201005.pdf)), accessed on 10 October 2021), the broadcast ephemeris data are complemented with a set of corrections along track, across track and radial, which are described by a piecewise linear function of time. Likewise, the clock corrections to the broadcast values are described by a piecewise quadratic function of time. Tests done on several Real Time and Orbit and Clock products indicate an update rate of typically 5 s, with a comparable latency. Specific RTCM messages 1060 and 1066 have been defined for GPS and Glonass SSR, respectively. We suggest that if sufficiently accurate orbit and clock predictions are available, the navigation message could be broadcast in a corrected form as a streamed RTCM (Radio Technical Commission for Maritime Services, www.rtcm.org, accessed on 10 October 2021) message as described in this paper, with additional reference frame information for GPS-like messages. Given the validity time of two hours, perhaps extendable to four hours with a refined gravity model, for GPS-like messages, and one hour for Glonass, the refresh rate could be considerably longer than SSR. If the SSR corrections are based on the improved navigation message, there would be a twofold advantage: (a) the SSR corrections would address the finest details of the orbit and clocks, for improved overall accuracy; (b) the user would have a redundancy in case of unavailable SSR data, as he would still be able to compute its position with a high accuracy ephemeris in a broadcast rather than SP3 format. Applicable RTCM messages could be 1019, 1020, 1042, 1045/6 for GPS, Glonass, Beidou and Galileo I/NAV and F/NAV, respectively (the two Galileo navigation messages refer to the two different ionospheric free linear combinations and corresponding clocks), and 1021 for the Helmert parameters [31]. In conclusion, we suggest that a corrected broadcasted message as it has been presented here, rather than the message broadcast by the various GNSSs, could be the basis for an even more accurate set of SSR corrections for both position and clocks.
## 3 Multiple-Access Reservation Receiver Initiation MAC (MAR-RiMAC)
### \"Request to Transmit\" (RtT) Signaling
The required number of minislots (i.e., sequence length) that is sufficient to identify the set of active devices is known to be in the order of \(T=\mathcal{O}(K\log N)\), in which \(N\) denotes the total number of devices (e.g., [55; 56]). Obviously, this number can be slightly increased in order to reduce the error probability. It was shown that the sequences themselves can be constructed randomly such that each entry (bit) in each sequence is determined according to the Bernoulli distribution with parameter \(p=1-2^{\frac{1}{T}}\). The maximum likelihood (ML) decoder, which picks the best-matched set of devices for potentially generating the binary outcome, can be used to identify the signaling set. In addition, several more efficient decoding algorithms--at the expense of slightly longer sequences--are proposed in the literature for identifying the signaling devices (e.g., [55; 56]).
## 2 Proposed Antenna Structure
### Analysis and Parametric Study  
From the previous section, it can be noticed that the dimension of the quadrilateral-shaped strip can affect the 3 dB AR. Therefore, a parametric study was utilized to show  
Figure 4: ARs of the designed four antennas.  
Figure 5: Surface current density at 5.8 GHz during different orthogonal phases.  
its effect. Figure 6 shows the effect of \(L_{4}\) on the antenna's performance. By increasing the length of \(L_{4}\) from 1.45 to 7.45 mm, the antenna was operated from 4 to 9 GHz with a good impedance bandwidth as shown in Figure 6a, while the 3 dB AR bandwidth decreased as illustrated in Figure 6b. When \(L_{4}\) = 1.45 mm, the 3 dB AR bandwidth was extended from 4.48 to 4.8 GHz. Additionally, when \(L_{4}\) = 4.45 mm, the 3 dB AR bandwidth was extended from 4.48 to 6.11 GHz. Finally; when \(L_{4}\) = 7.45 mm, the 3 dB AR bandwidth was extended from 4.7 to 5.5 GHz. The length of \(L_{4}\) was chosen to be 4.45 mm.  
Furthermore, Figure 7 shows the W6 effect on the antenna's performance. By increasing the length of W6 from 2 to 3 mm, while keeping \(L_{4}\) = 4.45, the antenna was operated from 4 to 9 GHz with a good impedance bandwidth as illustrated in Figure 7a, while the 3 dB AR bandwidth decreased as shown in Figure 7b. When \(W_{6}\) = 2 mm, the 3 dB AR bandwidth was extended from 4.48 to 6 GHz. Moreover, when \(W_{6}\) = 2.5 mm, the 3 dB AR bandwidth was extended from 4.48 to 6.11 GHz. Finally, when \(W_{6}\) = 3 mm, the 3 dB AR bandwidth was extended from 4.48 to 5 GHz and from 5.6 to 6.2 GHz. The length of W6 was chosen to be 2.5 mm. Finally, by elaborating on the parametric study outcomes, the final dimensions achieved the desired bandwidth from 4 to 9 GHz and satisfied the 3 dB AR bandwidth from 4.48 to 6.11 GHz.
# Implementing an Industry 4.0 UWB-Based Real-Time Locating System for Optimized Tracking
## 1 Introduction
The main wireless tracking technologies are: (i) ultrasound; (ii) Bluetooth; (iii) Wi-Fi; (iv) dual-band Wi-Fi that calculates the position of the tag based on received signal strength identification (RSSI) measurements from both the 2.4 GHz and 5 GHz bands; (v) radio frequency identification (RFID); and (vi) ultra-wideband technology. The main visible tracking technologies are:field of view. In the case of wireless signal tracking, it refers to the presence of a direct signal path between the transmitter and receiver. Technologies within the wireless signal and pedestrian dead reckoning (PDR) tracking categories are capable of functioning under NLOS conditions, while visible tracking systems are limited to LOS conditions. Despite the advancements in UWB-based RTLS, challenges such as cost-efficiency, scalability, and accurate localization in NLOS scenarios persist. This study addresses these gaps by introducing an optimized algorithm to minimize the impact of NLOS by attempting to exclude NLOS measurements from the tag's position calculation; it also introduces a method that needs only two anchors to calculate the tag's position. The experiments showcase that the proposed algorithm improves the positioning error when there is an NLOS range measurement in one of the three ranges, achieving accuracy comparable to the system's performance at LOS points. The innovation of this approach lies in its ability to sustain high positioning accuracy in environments with numerous obstacles and limited LOS measurements. Furthermore, it can be utilized in various positioning algorithms as a fallback solution when the NLOS range correction is ineffective. The proposed RTLS implementation uses IoT hardware devices and wireless signals based on UWB technology to track objects around an industrial facility layout. With respect to the software layer, open-source software libraries were employed for the development of the application programming interface (API). The developed tool relies on the IoT backbone mechanism for the real-time logging of intralogistics and implements a user-friendly interface that: (i) monitors the assets in real time; (ii) stores their locations; (iii) calculates the total distance travelled; and (iv) tracks and stores the exact path followed. The rest of the paper is structured as follows. The Literature Review (Section 2) analyzes the technological background of RTLS implementations and provides a technological comparison; the state-of-the-art RTLS solutions are also discussed. Section 3 presents the tracking methods, the proposed localization algorithm, and the developed RTLS. Section 4 presents the results of the developed RTLS system. Finally, the conclusions are given in Section 5.
## 3 Results  
### Mutation in the aceF Gene Reduces the Expression of Type III Secretion System Genes  
In our previous screening for metabolic genes that influence bacterial cytotoxicity, we found that an _aceF_::Tn mutant displayed defective cytotoxicity [22]. AceF, AceE and LpdG form the pyruvate dehydrogenase that connects the glycolysis pathway and the tricarboxylic acid cycle (Figure 1). To verify the role of AceF in bacterial cytotoxicity, we constructed an _aceF_ in-frame deletion mutant. The deletion of the _aceF_ gene reduced the cytotoxicity, which was restored by complementation with an _aceF_ gene (Figure 2A). In _P. aeruginosa_, the T3 SS plays an important role in bacterial cytotoxicity. In agreement with the reduced cytotoxicity, the mutation of _aceF_ reduced the expression of the T3 SS genes, including the regulatory genes _exsA_ and _exsC_, the structural gene _pcV_ and the effector genes _exoU_, _exoT_ and _exoY_ (Figure 2B, Figure S1). Complementation with the _aceF_ gene or the overexpression of the _exsA_ gene restored the expression of these genes (Figure 2B). These results suggest that AceF affects bacterial cytotoxicity by regulating the expression of the T3 SS genes.  
Figure 1: AceE, AceF and LpdG link glycolysis and the tricarboxylic acid (TCA) cycle.
# Decentralized Documentation of Maritime Traffic Incidents to Support Conflict Resolution
## 4 Concept
### Data Recorder  
After each participant has found a \(TSA_{selected}\), the local documentation of the incident can begin. The Data Recorder is responsible for managing the data's recording, signing and persistence. Figure 5 shows the functionality of the Data Recorder.  
Initially, participants decide for themselves whether they want to continue the current recording of the event. Every participant can choose when to end the recording independently from the other participants since the end of an incident can be interpreted differently. As the recorded data is usually live data, the data must first be split into regular chunks so that the data can be signed by the \(TSA_{selected}\) at all. Chunks can be formed in different ways (fixed size, fixed time span, etc.). Depending on the use case and individual preferences of the participants, a different way may be favored. Therefore, the participants can also decide by themselves under which conditions they subdivide their data. The chunk is then hashed using SHA-256 and transmitted to the \(TSA_{selected}\). Analogous to the signing process in Figure 1, the hashed chunk is hashed again by the \(TSA_{selected}\) and signed with the private key of the \(TSA_{selected}\). Afterwards, the resulting time stamp response (TSR) is sent back to the appropriate participants so they can persist the TSR together with the original data chunk locally on its own infrastructure. This process is repeated until the participant decides that the hazardous situation has ended, and proof of the process is not required anymore.
# Modeling Wicking Fabric Inhibition Effect on Frost Heave
## 6 Conclusions  
The findings from this study can be summarized as follows:  
1. A THM coupled FE model, which can simulate the freezing process of unsaturated soil, was combined with an evaporation model to evaluate the WF inhibition effect of frost heave under different situations. The proposed model can describe the influence of the surrounding environment, such as the saturation and temperature of the soil, on WF.
2. To examine the validity of the proposed model, the simulation results were compared to the experimental results. As a result, it was verified that the proposed model could sufficiently predict the temperature, moisture, and frost heave of the soil column in the frost heave test, and that the proposed model could simulate the suppression effect of WF on frost heave under different conditions.
3. The results from both the experimental and numerical simulations demonstrate that WF can effectively inhibit the occurrence of frost heave. This indicates that the proposed model is able to reproduce the transient evaporation process of WF during freezing, whose rate changes in accordance with the soil saturation and temperature, and that it can simulate the inhibition effect of WF on frost heave under different conditions.
4. The soil type, GWL, and cooling rate affect the inhibition effect of WF on frost heave strain in frost-susceptible soils. The WF was more effective in reducing frost heave on sandy soils than on clay soils. For the same freezing time, a higher freezing rate tends to cause less frost heave, and the inhibition effect of WF on frost heave is correspondingly weakened. On the other hand, when the GWL is increased, it also reduces the effectiveness of WF in preventing frost heave.  
Conceptualization, supervision, funding acquisition, and writing--review and editing, T.I.; methodology, software, validation, and writing--original draft, Y.W. funding acquisition, K.M. and C.U.; experiment conduction, T.Y. and S.O. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Grant-in-Aids for Scientific Research, grant numbers (A) (16H02360) and (B) (17H03307) from the Japan Society for the Promotion of Science (JSPS) KAKENHI. The authors also acknowledge the financial support from the China Scholarship Council (201907565040).  
Data Availability Statement:Data sharing is not applicable.  
This research was supported, in part, by Grant-in-Aids for Scientific Research (A) (16H02360) and (B) (17H03307) from the Japan Society for the Promotion of Science (JSPS) KAKENHI. The authors also acknowledge support from the China Scholarship Council.  
The authors declare no conflict of interest.
## 2 Materials and Methods
### Qualitative Assessment of Image Quality  
Three radiologists (each with more than 5 years of experience in reporting chest CT images) were blinded to the protocols and were presented with the 15 CT scans in randomised order. They independently scored each CT scan for nodule detectability according to a 5-point Likert Scale as described previously [5; 18; 35; 36; 37; 38; 39]: 1 = non-diagnostic image quality, strong artifacts, unsuitable for diagnosis. 2 = limited diagnostic confidence, severe blurring creates uncertainty in assessment. 3 = moderate diagnostic confidence: moderate blurring causes restricted assessment. 4 = good diagnostic confidence, slight blurring but evaluation is unrestricted. 5 = excellent diagnostic confidence, clear images, artifact free for a confident diagnosis.  
The optimum protocol was determined to be the protocol that delivers the lowest effective dose, given that it achieves a subjective image quality score of at least 3.
# Multi-Wavelength Quantum Key Distribution Emulation with Physical Unclonable Function
### Practical Implementation, Attacks, and Decoy States  
In theory, BB84 seemingly offers unconditional security, but in practice, weaknesses exist due to hardware limitations. Components such as the single photon detectors introduce problems, and attempts to solve these problems exist ([15]), but the most notable limitations stem from imperfect single photon sources. In order for the protocol to work, [PERSON] must have a perfect single photon source that emits one photon per pulse. However, in practice, single photon sources are imperfect and may emit more than one photon per pulse and sometimes zero photons per pulse. An eavesdropper, [PERSON], can exploit this issue through a photon number splitting (PNS) attack where she \"splits\" the extra photons on multi-photon pulses, and allows the remaining photons to continue transmission to [PERSON]. This way, [PERSON] can measure the extra photons without alerting [PERSON] and [PERSON]. [PERSON] may also block all single photons from reaching [PERSON] to ensure only the multi-photon pulses are used [7]. One method of combatting this attack includes using decoy states that [PERSON] cannot easily distinguish from the real states, so she will make detectable changes to the decoy state yield [16; 17; 18]. While this method and other modifications to decoy state protocols help mitigate information obtained by [PERSON], the imperfections of the practical BB84 system remains a major weakness.
# Research on the Robustness of Interdependent Networks under Localized Attack
## 1 Introduction
Very recently, some researchers have studied the properties of interdependent networks from the point of view of recovery [34, 35, 36], propagation [37, 38], and fuzzy information attack [39]. Moreover, the robustness of network of networks (NON), which is an extension of two-layer interdependent networks, has been examined. In particular, [PERSON] and [PERSON] et al. [40, 41, 42, 43, 44, 45] systematically studied the percolation process of chain-like, star-like, and tree-like NON by analytical and numerical methods. Although there are many studies on interdependent networks, most of them are based on random failure or malicious destruction, while very few articles focus on localized attacks, which are used to simulate the effect of natural disasters, such as earthquakes, on critical infrastructures [23]. In previous studies, all nodes in an attack area (or ratio of affected nodes, expressed with \(p\)) of a localized attack will fail, but the fact is not always like that. For example, the impact of earthquakes may be very large, but infrastructure nodes in the scope will not necessarily fail, and the failure probability of nodes should decrease with the distance from epicenter. Based on this consideration, this paper studies the robustness of interdependent networks under a new localized attack strategy, providing a reference for the design of a more robust critical infrastructure system. The rest of this paper is organized as follows: The second section introduces cascading failures of interdependent networks, and the concept of a failure probability degradation model of localized attack. In the third part of the paper, simulation and analysis is conducted on four kinds of isolated networks and corresponding interdependent networks under the new localized attack, in addition, we analyze the effect of coupling preference and strength on new attack strategies. The last part summarizes the whole text and looks forward to the future work.
# Topology Optimization of Functionally Graded Structure for Thermal Management of Cooling Plate
## 2 Methodology
### Heat-Fluid Coupling
#### 2.1.1 Fluid Flow  
Generally, the coolant flowing within the cooling plate exhibits low speed and a stable laminar flow. Consequently, the incompressible laminar Navier-Stokes equations are employed to describe the flow. To distinguish between the fluid and solid regions, the Brinkman penalty force is added to the Navier-Stokes equations:  
\[\rho_{f}(u\cdot\
abla)u=\
abla(-pI+\mu(\
abla u+(\
abla u)^{T}))-\alpha u \tag{1}\]  
\[\
abla\cdot u=0 \tag{2}\]  
Equations (1) and (2) describe the law of the conservation of momentum and mass, respectively, where \(\rho_{f},u,p,\mu\), and \(\alpha\) define the fluid density, velocity, pressure, dynamic viscosity, and Brinkman penalty factor, respectively. The Brinkman penalty strategy distinguishes a solid and a fluid through the introduction of a virtual body force \(\alpha u\), where the fluid velocity approaches 0 when the body force is at a large value, and the corresponding part is the solid phase.
## 5 Publishers over the Years  
In this section, we will be discussing some trends regarding publishers over the years. A chord diagram was made using Raw Graphs, an online graph tool, to represent a measure of publishers publishing in a specific year.  
The given graph in Figure 13 shows the top 18 publishers from 2010 to 2024 who published at least one paper in their respective target years. Here are some trends and observations:  
* Prominent Publishers: Springer and Elsevier are the most prominent publishers, indicated by their strong connections over multiple years. They have consistently published works across a wide range of years, demonstrating their significant presence in academic publishing.
* Recent Publications: IEEE Computer Society, Springer, and Elsevier show substantial activity in recent years (2021-2024). This indicates a trend where these publishers are heavily involved in contemporary academic and scientific literature.
* Emerging Publishers: MDPI and PeerJ Inc have been connected for multiple years, suggesting they are emerging as notable publishers in recent times. Their increasing connections indicate growing influence and publication volume.
* Diverse Publishers: Publishers like Springer Nature and Cambridge University Press have connections across a wide range of years, indicating their long-standing involvement in academic publishing.  
Figure 12: The citation network of places.  
* Consistent Contributors: Publishers such as Elsevier Science Inc, Springer Heidelberg, and IEEE Computer Society show consistent publication activity over the years, suggesting a stable and ongoing contribution to the academic and scientific community.
* Specialised Publishers: Some publishers have a focused presence in specific years, such as Academic Press Ltd in earlier years and Nature Portfolio in more recent years. This may indicate periods of heightened activity or focus on particular research areas during those times.
* Publication Peaks: Certain years, particularly 2023 and 2024, show high publication activity across multiple publishers, suggesting recent years have seen a surge in academic output.  
These trends illustrate the dynamic landscape of academic publishing, with major players maintaining their influence while new and specialised publishers are emerging and contributing significantly to the field.