esa-sceva/satcom-chunk-collection huggingface dataset:
# Failure Modelling of CP800 Using Acoustic Emission Analysis
###### Abstract  
Advanced high-strength steels (AHHS) are widely used in many production lines of car components. For efficient design of the forming processes, numerical methods are frequently applied in the automotive industry. To model the forming processes realistically, exact material data and analytical models are required. With respect to failure modelling, the accurate determination of failure onset continues to be a challenge. In this article, the complex phase (CP) steel CP800 is characterised for its failure characteristics using tensile tests with butterfly specimens. The material failure was determined by three evaluation methods: mechanically by a sudden drop in the forming force, optically by a crack appearing on the specimen surface, and acoustically by burst signals. As to be expected, the mechanical evaluation method determined material failure the latest, while the optical and acoustical methods showed similar values. Numerical models of the butterfly tests were created using boundary conditions determined by each evaluation method. A comparison of the experiments, regarding the forming force and the distribution of the equivalent plastic strain, showed sufficient agreement. Based on the numerical models, the characteristic stress states of each test were evaluated, which showed similar values for the mechanical and optical evaluation method. The characteristic stress states derived from the acoustical evaluation method were shifted to higher triaxialities, compared to the other methods. Matching the point in time of material failure, the equivalent plastic strain at failure was highest for the mechanical evaluation method, with lower values for the other two methods. Further, three Johnson-Cook (JC) failure models were parametrised and subsequently compared. The major difference was in the slope of the failure models, of which the optical evaluation method showed the lowest slope. The reasons for the differences are the different stress states and the different equivalent plastic strains due to different evaluation areas.  
b utterfly specimen; failure analysis; AHSS; Johnson-Cook failure model +
Footnote †: journal: Applied Sciences
## 3 Results and Discussion
### Numerical Analysis of Spatiotemporal Effect  
#### 3.2.1 Pore Water Pressure  
Before dewatering, the water levels inside and outside the pit were nearly equal, as shown in Figure 8a, with the diaphragm wall serving as a waterproof curtain. In the numerical model, the pore water pressure on the diaphragm wall was assumed to be 0 kPa,  
Figure 6: Surface settlement outside the pit: (**a**) surface settlement outside the west end head pit; (**b**) surface settlement outside the standard section pit. D is the distance from the pit. Notes\(-\)excavation step sequence: \(1-\)arrangement of the first steel support; \(2-\)arrangement of the second steel support; \(3-\)arrangement of the third steel support; \(4-\)arrangement of the fourth steel support; \(5-\)excavation completed.  
Figure 7: The relationship between the surface settlement outside the pit and the maximum horizontal displacement of the retaining wall: (**a**) the west end well; (**b**) the standard section.  
considering the impermeability of the wall and the dissipation of excess pore water pressure near the interface. Outside the diaphragm wall, the soil layer's pore water pressure was consistent with initial equilibrium. During the phased dewatering and excavation of the pit, as shown in Figure 8b,c, under the influence of the seepage field within the pit, the water level inside gradually decreased, with groundwater around the pit seeping into the pit. Due to the deep insertion of the waterproof curtain and the primary focus on dewatering the shallow mucky soil layers, the vertical flow of groundwater in the mucky soil layers dominated, with more groundwater flowing from beneath the pit into the pit than from the outside to the inside laterally. Overall, dewatering has little impact on the water level outside the pit, but it significantly affected the water level at certain depths below the pit base, reducing it. Once the excavation was completed, the water level inside the pit dropped to about 1 m below the pit bottom, significantly lower than the water level outside, because it was cut off by the diaphragm wall. Dewatering was necessary to lower the water level below the excavation surface, ensuring dry excavation. The impact of dewatering on pit stability was considered, and water pressure was calculated in the design.  
Figure 8: Pore water pressure contour with different construction steps: (**a**) before excavation; (**b**) excavation of third floors; (**c**) final excavation.
# A Compact Monopole Wideband Antenna Based on DGS
## 4 Fabrication, Measurements, and Comparison  
The proposed fabricated antenna was shown in Figure 14a, while the measurement setup in the chamber room is provided in Figure 14b. The suggested prototype was fabricated on a Taconic TLY substrate (\(\epsilon_{r}\) = 2.2, tan \(\delta\) = 0.0009, h = 1.524 mm) and is tested using a vector network analyzer (VNA). The comparison of S\({}_{11}\) values between simulated and measured results (Figure 15) shows that the fabricated antenna achieves dual-band frequencies of 4.115-13.115 GHz and 15.32-18.425 GHz, with a total bandwidth of 12.1 GHz at VSWR \(<\) 2. In contrast, the simulated antenna has a bandwidth of 4.08-18.92 GHz. Limitations in the fabricated antenna's bandwidth and S\({}_{11}\) values are attributed to fabrication tolerances, discrepancies between actual and nominal dielectric constants, dielectric losses, environmental influences, impedance matching issues, and the transition effects between the SMA connector and microstrip. Despite these differences, the overall consistency between simulated and measured results confirms the antenna's suitability for various wireless communication applications. Future designs should focus on minimizing these discrepancies through improved fabrication processes and material selection.  
Figure 14: (a) Prototype of the proposed antenna and (b) antenna set up in the chamber rooms.  
Figure 15: Refl. coefficient (S\({}_{11}\)) of simulated result and measured result.
## 3 Governing Equations of CNTRC Beams
### The Governing Equation for CNTRCs Considering the Thickness Effect
The expression of the electromagnetic actuator can be simplified as:  
\[\frac{1}{2}\frac{C_{0}V_{x}^{2}}{[d-w]^{2}}-\frac{1}{2}\frac{C_{0}V_{x}^{2}}{[ d+w]^{2}}\approx\frac{2C_{0}V_{x}^{2}}{d^{2}}\bigg{[}\frac{w}{d}+2\Big{(}\frac{w}{d} \Big{)}^{3}+3.0925\Big{(}\frac{w}{d}\Big{)}^{5}\bigg{]} \tag{42}\]  
The maximum error between the left and right expressions from Equation (42) was \(3.3\times 10^{-6}\) for \(w/d\in[0,0.15]\). In this manner, the virtual work is given by:  
\[ \begin{array}{c}\delta W=\int_{0}^{L}\big{(}q+\overline{q}\big{)}\delta wdx +P_{0}w^{\prime}\delta w^{\prime}+\overline{N}\delta u\big{|}_{0}^{L}+ \overline{N}\delta w\big{|}_{0}^{L}+\overline{P}\delta w^{\prime}\big{|}_{0}^{ L}+\overline{R}\delta\theta\big{|}_{0}^{L}+N^{(1)}\delta f+M^{(1)}\delta g+P^{(1)} \delta(u^{\prime}-\theta)\end{array}  \tag{43}\]  
where having considered the identity:  
\[ \begin{array}{c}-3\frac{\partial}{\partial x}\big{(}-Mw^{\prime}w^{\prime \prime}\big{)}+\frac{\partial^{2}}{\partial x^{2}}\bigg{[}M\bigg{(}1-\frac{3}{2 }{w^{\prime}}^{2}\bigg{)}\bigg{]}=\frac{\partial}{\partial x}\bigg{[}\frac{ \partial M}{\partial x}\bigg{(}1-\frac{3}{2}{w^{\prime}}^{2}\bigg{)}\bigg{]} \end{array}  \tag{44}\]  
one gets:  
\[ \begin{array}{c}\overline{N}=\ N|_{0}^{L},\ \overline{M}=\ \bigg{[}Nw^{\prime}\bigg{(}1-\frac{3}{2}{w^{ \prime}}^{2}\bigg{)}-\frac{\partial M}{\partial x}\bigg{(}1-\frac{3}{2}{w^{ \prime}}^{2}\bigg{)}-\frac{\partial P}{\partial x}\bigg{]}\bigg{|}_{0}^{L};\ \overline{P}=\ \bigg{[}P-M\bigg{(}1-\frac{3}{2}{w^{\prime}}^{2}\bigg{)}\bigg{]} \bigg{|}_{0}^{L};\ \overline{R}=\ -P|_{0}^{L}\end{array}  \tag{45}\]Now, applying the Hamilton principle:  
\[\int_{t_{1}}^{t_{2}}{(\delta K-\delta U+\delta W)dt}=0 \tag{46}\]  
the governing equations of motion are obtained as:  
\[\frac{\partial N}{\partial x}=I_{0}\ddot{u}+(I_{3}-I_{1})\ddot{w}^{\prime}-I_{3}\ddot {\theta} \tag{47}\]  
\[\frac{\partial^{2}}{\partial x^{2}}\Big{[}P-M\Big{(}1-\frac{3}{2}{w^{\prime}}^ {2}\Big{)}\Big{]}-\frac{\partial\mathcal{O}}{\partial x}+3\frac{\partial}{ \partial x}\Big{[}Mw^{\prime}w+\text{Nww}\Big{(}1-\frac{1}{2}{w^{\prime}}^{2} \Big{)}\Big{]}+q-\overline{q}+P_{o}w^{\prime\prime}= \tag{48}\]  
\[(I_{3}-I_{1})\ddot{w}^{\prime}+(I_{5}-2I_{4}+I_{2})\ddot{w}^{\prime}+(I_{4}-I _{5})\ddot{\theta}^{\prime}-I_{0}\ddot{w}\]  
\[\frac{\partial P}{\partial x}-Q=I_{3}\ddot{u}+(I_{5}-I_{4})\ddot{w}^{\prime}-I _{5}\ddot{\theta} \tag{49}\]  
Using the notations:  
\[(A_{11},B_{11},D_{11},E_{11},F_{11})^{T}=\int\limits_{A}Q_{11}\Big{(}1,z,z^{2 },zH(z),H^{2}(z)\Big{)}^{T}dA;\ A_{55}\int\limits_{A}Q_{55}H(z)dA \tag{50}\]  
from Equations (32) and (47), we can obtain:  
\[N\Big{(}1-(ea)^{2}\
abla^{2}\Big{)}=A_{11}\bigg{(}1-l^{2}\frac{\partial^{2}}{ \partial x^{2}}\bigg{)}f \tag{51}\]  
where \(f\) is given in Equation (21).
## 2 Materials and Methods  
### Dental Laser  
Since the previous study verified the stability of implant treatment using a diode laser with 940 nm [14], three dental diode lasers with wavelengths from 940 to 980 nm were used in the present study: K2 mobile (Hulaser, Seoul, Korea) with a wavelength of 980 nm, EpicTM 10 (Biolase, CA, USA) with a wavelength 940 nm, and Saeshin diode laser with a wavelength 980 nm (Saeshin, Daegu, Korea). The laser fiber tip has a circular shape with a diameter of 400 \(\upmu\)m, and an identical tip was used for three dental diode lasers. The laser fiber tip was unmoved, and in contact vertically with the titanium disk surface while irradiation was performed for a period of 15 s. The three dental diode lasers were used only in the continuous wave mode with a flexible fiber with a focused spot size of 0.4 mm diameter. All the preselected laser parameters for the three lasers can be seen in Table 1. All the preselected laser parameters were determined using a calibrated power meter system (NovaII; Ophir Photonics, North Logan, UT, USA).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Laser Types** & **Output Power** & **Actual Power** & **Power Density (W/cm\({}^{2}\))** & **Energy Density (kJ/cm\({}^{2}\))** \\ \hline \multirow{3}{*}{**K2 mobile** (\(\lambda\) = 980 nm)} & 1.0 W & 1.1812 W & 969.2 & 14 \\ \cline{2-5}  & 2.0 W & 2.2378 W & 1905.2 & 28 \\ \cline{2-5}  & 3.0 W & 3.4866 W & 2715 & 40 \\ \hline \multirow{3}{*}{**Epic 10 TM** (\(\lambda\) = 940 nm)} & 1.0 W & 0.7628 W & 607.4 & 9 \\ \cline{2-5}  & 2.0 W & 1.4548 W & 1157.4 & 17 \\ \cline{2-5}  & 3.0 W & 2.2612 W & 1788 & 26 \\ \hline \multirow{3}{*}{**Saeshin** (\(\lambda\) = 980 nm)} & 1.0 W & 0.8604 W & 668.6 & 10 \\ \cline{2-5}  & 2.0 W & 1.6334 W & 1334.6 & 20 \\ \cline{1-1} \cline{2-5}  & 3.0 W & 2.4698 W & 1957.8 & 29 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Parameters of three dental diode lasers.
## 2 Materials and Methods
### Animal Preparation and Surgical Procedure  
Thirty male, inbred Wistar albino rats weighing over 300 g were included in the study after acclimating the laboratory environment for 10 days. The rats were not involved in any previous experiments and were also screened for any diseases. They were kept in metal cages with access to water and food ad libitum. The rats were maintained in 22 \(\pm\) 2 \({}^{\circ}\)C environmental conditions with 12 h of light and 12 h of darkness. The animals were fasted for 24 h before the procedure.  
Five groups were randomly formed according to the cages in which the animals were housed:  
1. Control group (\(n=6\));
2. Scaffold group (\(n=6\));
3. Scaffold + PRP group (\(n=6\));
4. Scaffold + Mesenchymal stem cell group (\(n=6\));
5. Scaffold + PRP + Mesenchymal stem cell group (\(n=6\)).  
Before the surgical procedure, the decellularized omentum was cut into 0.5 cm\({}^{3}\) pieces and was saturated with 0.5 mL PRP or 0.5 mL MSC or both PRP and MSC; it was outside the surgery site in a Petri dish and waited in room temperature (25 \({}^{\circ}\)C) for 5 min to adhere to the scaffold. All rats were anesthetized with a 50 mg/kg dose of intraperitoneal ketamine hydrochloride and 3 mg/kg xylazine combination injection. All rats were monitored by a veterinarian during the surgery. The surgical position of the rats was supine and both forelimbs were shaved. Bone defects sized 0.5 cm\({}^{3}\) were created in all rats in both radius bones with a 5 mm Kerrison rongeur. Periosteal elevation and muscle retraction were not performed in any rats. All rats in the same groups received the same treatment in both limbs. The bone defect site was treated according to the following group protocol: group 1, bone defect left empty; group 2, previously prepared decellularized omentum sized 0.5 cm\({}^{3}\) was placed on all rats' forelimbs; group 3, previously prepared decellularized omentumsized 0.5 cm\({}^{3}\), saturated with 0.5 mL PRP; group 4, previously prepared decellularized momentum sized 0.5 cm\({}^{3}\), saturated with 0.5 mL MSCs; and group 5, previously prepared decellularized momentum sized 0.5 cm\({}^{3}\), saturated with both PRP and MSCs 0.5 mL (Figure 1). No fixation method was used for the bone. Wound was closed with non-absorbable sutures. After the surgical procedure, while rats were under anesthesia, 15 mg/kg tramadol was used for postoperative analgesia. Each group of rats was labeled and caged in a separate cage with no restriction of activities.
## 5 Conclusions
### Limitations and Future Research Directions  
We examined the key technologies in optical networks from the perspective of SEPs. However, SEP applications proceed slowly; therefore, they only reveal the indispensable standard technologies but not the latest ones in the market, which is a considerable limitation of this study. We adopted the more mature CPC classification code to categorize the technical fields. The classification code only indicated the fields that require long-term funding and talent cultivation but neglected the detailed development process of the fields (e.g., the latest development trend of dense wavelength-division-multiplexed passive-optical-network, orthogonal frequency division multiplexing, and space division multiplexing). Hence, follow-up studies may conduct content analyses on individual patents to increase the depth of the research. Second, this study adopted the perspective of SEPs to discuss the focus of optical networks in the industry's standard setting. Through the observations of this study, we can see that optical networks have had substantial growth in the industry standard setting. In recent years, there have been 465 SEPs. Regarding standard setting, the number of SEPs on wireless communication devices and digital information transmission increased most quickly. However, future studies should investigate more detailed sub-topics and focus on expanding the key sub-topics reported by this study, such as wireless communication devices, digital information transmission, and multiplex communication, thereby integrating them into bigger categories. Consequently, the identification of the trend and need for talent development will attract the interest of a wider community. Moreover, we explored the global key technologies protected by SEPs from a macro-level perspective. Nevertheless, the motivation and necessity of filing SEP applications vary because technologies have different attributes and are developed under different industrial environments (e.g., electrical machinery, apparatus and energy have fewer SEPs [36]). We have only analyzed the technical fields disclosed by standard-setting organizations and SEPs. Future studies may employ data from other patent offices (e.g., the USPTO or EPO) to more precisely predict the development trends of novel technologies in optical networks.
# Results and Achievements of the ALLIANCE Project: New Network Solutions for 5G and Beyond
## 5 Trust Element
### Research Activity  
In the context of the ALLIANCE project, we have investigated how to leverage the properties of blockchains to share information between different trust domains, and the advantages and disadvantages of such system. We focused on two scenarios: first, recording the allocations and delegations of public IP addresses, as well as bindings of IP prefixes to Autonomous System Numbers (ASN) in a blockchain. Second, storing access control policies for networks belonging to different enterprises.  
Regarding the allocation of IP addresses, we have proposed storing IP prefixes in a blockchain similarly to cryptographic coins in financial blockchains, such as in Bitcoin [52]. This way, participants can exchange, transfer and split blocks of IP addresses as in a financial blockchain. As we mentioned, this approach does not rely on centralised CAs, and decentralises trust: users do not depend on the actions of the CAs, since each IP prefix is tied to the public-private keypair of the operator. In addition, we can add metadata to each transaction. Since these metadata are included with the blockchain transaction, they are cryptographically verifiable. Two metadata are especially interesting: Autonomous System Numbers (ASN) and IP addresses. In the first case, since we are binding an IP prefix to an ASN, we can use these data to validate BGP messages in the context of interdomain routing security. In other words, we can verify if an IP prefix should be originated by the legitimate ASN, or has been modified along the path. This approach is an alternative to the RPKI [53], the current system to perform such validation, which is based on centralised CAs [54; 55]. In the second case, we are binding an IP prefix to an IP address. This can be interpreted as a mapping of an overlay address to an underlay address, such as the ones used in mapping systems for SDN-based overlay networks. As we mentioned earlier, this mapping system can be used to share the location of 5G subscribers across networks from different operators.  
Figure 4: A blockchain can serve as a shared database between networks from different trust domains to share network metadata.  
With respect to access control policies, we focus on a scenario of different enterprises that want to allow access to some of their resources among them. The different enterprises leverage a blockchain to write their access control policies, and the routers query the blockchain to allow or deny connections. Since data in the blockchain is controlled by the associated private key owner, each enterprise can revoke any of their access policies at any moment. Moreover, we argue that a system based on a blockchain scales better than PKI-based alternatives such as cross-certification. A detailed evaluation of the scalability of this proposal can be found in [56].
###### Abstract  
While the existing research provides a wealth of information about the static properties of RTK receivers, less is known about their dynamic properties, although it is clear that the vast majority of field operations take place when the machine is moving. A new method using a MRA for the evaluation of RTK receivers in movement with a precise circular reference trajectory (\(r\) = 3 m) was proposed. This reference method was developed with the greatest possible emphasis on the positional, time and repeatable accuracy of ground truth. Four phases of the measurement scenario (static, acceleration, uniform movement and deceleration) were used in order to compare four different types of RTK receiver horizontal operation accuracy over three measurement days. The worst result of one of the receivers was measured at \(SSR\) = 13.767% in dynamic movement. Since the same \"low-cost\" receiver without an INS unit had \(SSR\) = 98.14% in previous static measurements, so it can be assumed that the motion had a very significant effect on the dynamic properties of this receiver. On the other hand, the best \"high-end\" receiver with an INS unit had \(SSR\) = 96.938% during the dynamic testing scenarios. The median values of the deviations were always better during uniform movements than during acceleration or braking. In general, the positioning accuracy was worse in the dynamic mode than in the static one for all the receivers. Error indicators (\(RMS_{err}\) and \(Me\)) were found several times higher in the dynamic mode than in the static one. These facts should be considered in the future development of modern agricultural machinery and technology.  
accuracy; precision; movement; dynamic properties; RTK; VRS; GNSS; INS; precision agriculture +
Footnote †: journal: Sensors
# Evaluation of the GPS Precise Orbit and Clock Corrections from MADOCA Real-Time Products
## 2 Data Sets and Evaluation Strategy  
Currently, the MADOCA real-time products could be obtained by RTCM SSR via internet, satellite, as well as RINEX SP3 format [14]. Considering the flexible accessibility and stability of products in the short- and long-term, the recorded MADOCA real-time products utilized in this paper were accessed from the JAXA website in SP3 format [16], which provides non-redundant, time-sorted real-time data records for GPS, GLONASS, and QZS-1 satellites including orbit, clock, and user range accuracy (URA) messages at 30-s intervals. The IGS final products from IGS data center of Wuhan University (www.igs.gnsswhu.cn) were taken as reference products for the products availability and accuracy evaluations.  
On the products availability evaluation, the integrality of the MADOCA real-time orbit and clock messages was accessed by comparing with IGS orbit and clock records epoch by epoch with over three month statistics, from 1 November 2018 to 31 January 2019.  
Moreover, on the products accuracy evaluation, the 7-parameters Helmert transformation was firstly conducted with daily products to unify the coordinate datum on the orbit evaluation, and the clock products were evaluated with the standard deviations by taking the mean satellite clock as reference. To avoid interpolation errors, the accuracy comparison intervals were taken exactly the same as IGS products, which are 15 min for orbits and 30 s for clocks. And the statistics of the SISRE were also used to evaluate the MADOCA products accuracy on the ranging measurement.  
Over 20 globally distributed IGS stations were used to simulate the real time PPP performance with the open source RTKLIB package. The selected IGS stations are chosen evenly distributed but avoiding the MADOCA network stations, and the data processing interval is taken as 30 s to avoid the infection of interpolation errors.
## 2 Categorization Approach
### Categorization Method  
For the classification of the analyzed PA-related solutions, we developed a two-fold approach based on the data lifecycle model presented above as well as on the technological categorization of the solutions (38 technological subcategories have been defined). The categorization was performed according to the main focus point(s) of each solution. As many solutions encompass different technologies and/or data lifecycle stages, finding a solution in one category does not exclude the possibility of this solution using and/or facilitating technologies from other categories as well.