esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Results and Discussion
### Discussion  
The major inconvenience of the DIC, compared to other classical instrumentation in dynamics, is the special care taken in the experimental set-up of the tested structure, especially the speckle realization and the lighting, whereas other sensors such as accelerometers and vibrometers are more \"ready-to-use\". However, the use of full-field measurements by means of DIC to perform a modal analysis offers many advantages. Given that the surface of the structure under test is not \"mechanically\" scanned, the duration of the tests is shorter than that needed using scanning vibrometers. As previously underlined, the main advantage of the full-field measurements is the large amount of data points. This amount of data allows us to increase the spatial resolution, leading to a better description of the mode shapes.  
Even if the resolution is lower than for accelerometers and vibrometers, we were able to identify using DIC the first six modes of a clamped-clamped beam and the first eight ones of a cantilever beam. The highest natural frequency determined using the full-field measurement here is up to 2200 Hz.  
Table 6 summarizes the pros and cons of both measurement techniques considered in this research. We should note that the deviation observed in the identification of the modal damping ratios of some modes with DIC measurements is partially due to the large number of measurement points.
# A New String Edit Distance and Applications
## 2 Restricted Forensic Levenshtein Distance
### Details of the RFL Algorithm
#### 2.3.2 A Note on Weighted Edit Distance  
In a setting where different edits happen with different frequencies, one might want to weight edits differently from each other. This could be because DNA exhibits higher rates of changing a particular character to another, or in spelling correction because certain letters are closer to others on the keyboard. For example, inserting an A could be penalized more than any other letter, and substituting C for the letter G could be incentivized. This could be done by raising the insertion cost of an A to 2 and lowering the substitution cost of G \(\rightarrow\) C to 0.5. The edit distance algorithm remains the same, but whenever those edits are performed, the cost is different. This might change the optimal edit path from one string to another. Normally, converting CAT into TGT would be two substitutions: C \(\rightarrow\) T and A \(\rightarrow\) G. In the case where all substitution costs are equal to 4 and insertion and deletion costs are still equal to 1, the previous edit path involving two substitutions would cost a total of 8, and a new minimal-cost path would be CAT \(\rightarrow\) AT \(\rightarrow\) T \(\rightarrow\) GT \(\rightarrow\) TGT, which would cost 4. This could be made much more complicated by changing every possible edit cost to be different than every other. The dynamic programming algorithm solution is able to take any possible assortment of costs and compute the minimal cost given those parameters.  
This can easily make the distance non-commutative, i.e., it is a directed distance. In a case where the substitution cost of C \(\rightarrow\) G is 3, but all other costs remain equal to 1, then the distance from CAT to GAT is 2 (delete C, insert G; this is still less costly than changing C to G directly), but the distance from GAT to CAT is 1 (changing G to C still costs 1). Therefore the distance hereafter is referred to as being from a sequence \(s\) to another sequence \(t\), which represents that the edits begin at \(s\) and change into \(t\). A library for the weighted Levenshtein, optimized in Cython, is available [32].
## 5 Discussion  
In view of the study to improve the energy efficiency of the industrial refrigeration system for a meat processing factory, it has been observed that the combination of measures by means of capacity variation by mechanical slide of the refrigeration compressors together with speed variation actions produces better results that translate into a substantial improvement in combined energy efficiency.  
The analysis should consider the whole of the entire refrigeration production system considering the total number of operating hours; this makes the best decision to be made, since it is not necessary to install speed regulation in all the electric motors of the compressors, but rather in those that make the regulation of the industrial refrigeration system more optimal to the joint capacity. This measure reduces the investment costs to be made for the total improve of the system.  
These combined measures improved on energy saving close to 400 MWh per year, which entails an equivalent reduction of CO\({}_{2}\) emissions of 147.9 tons.  
Likewise, it has been found that after a period of application of the measures, there are other advantages in addition to energy savings, such as improved maintainability due to a better distribution of capacity and preventing components from operating excessive hours and others few. In the same way, the reliability of the system has increased due to the reduction of failures due to the more efficient operation of the motors and the reduction of starts.  
These collateral results are important in the operation and maintenance of this type of industrial plant [1; 16], being one of the areas of concern to achieve efficient industries with respect to the environment [17; 18; 19; 20]. With all this, the importance of combining different regulation systems in industrial refrigeration compressors is shown in order to improve energy efficiency, so that it can be understood by professionals in the sector and introduce new lines of research to improve the efficiency of these systems.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**COMP.A9** & **Time** & **Absorbed** & **Refrigeration** & **COP** & **Abs.** & **COP** & **Specific** & **Estimated** \\
**Capacity (\%)** & & **Power(kW)** & **Power (kW)** & **(no VSD)** & **Power (kW)** & **(VSD)** & **Saving** & **Saving** \\ \hline
95–100 & 13.53\% & 270.10 & 403.90 & 1.5 & 278.20 & 1.45 & 2.00\% & 6.404 \\  
\hline
0–10 & 44.95\% & 0.00 & 0.00 & 0.00 & 0.00 & 0.00 & 0.00 & 0.00 \\ \hline \end{tabular}
\end{table}
Table 4: Energy saving results due to speed variation in compressor N\({}^{\circ}\). 9.
# Analyzing the Biomechanical Characteristics of Ski Jumping Take-Off Phase Based on CFD
## 3 Results
### Drag Characteristics at Different Moments
#### 3.2.2 Aerodynamic Characteristics at the End Moment of the Take-Off Phase (EMT)  
The results reveal significant differences in the air drag experienced by Chinese athletes compared to NW elite athletes during the take-off phase. The discrepancies are most pronounced in the drag experienced by the lower legs, torso, and overall system, while the differences in drag between the left and right thighs of NW elite athletes are relatively minor. Specifically, at the end of take-off, the drag values for the left and right lower legs of Chinese athletes are 74.06 N and 37.02 N, respectively, whereas NW elite athletes experience considerably lower drags of 0.15 N and 0.79 N. Concurrently, the torso drag for Chinese athletes is also significantly higher, at 76.06 N, compared to 10.19 N for NW elite athletes (Table 4). Furthermore, Table 4 shows that the total drag, total lift, and lift-to-drag ratio of the athlete-board system vary between Chinese and NW elite athletes during take-off. For Chinese athletes, the total drag is 170.18 N, the total lift is 67.10 N, and the lift-to-drag ratio at the transition into the early flight phase is 0.39. In contrast, NW elite athletes experience a total drag of 84.15 N, a total lift of 95.18 N, and a lift-to-drag ratio of 1.14 during their transition into the early flight phase.  
As shown in Figures 7 and 8, there are notable differences in the static pressure experienced by Chinese and NW elite athletes during the EMT. NW elite athletes, during the completion of take-off, generally lean forward with adequate forward momentum and fully extend their lower limbs. This posture results in relatively lower static pressure across their body segments and the formation of low-pressure zones. In contrast, Chinese athletes do not lean forward as much during the EMT, resulting in comparatively higher static pressure on various body segments.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **LLD (N)** & **RLD (N)** & **LHD (N)** & **RHD (N)** & **TOD (N)** & **TD (N)** & **TL (N)** & **L/D** \\ \hline CA & 74.06 & 37.02 & 8.31 & 9.54 & 76.06 & 170.18 & 67.10 & 0.39 \\ \hline NWA & 0.15 & 0.79 & 6.48 & 9.47 & 10.19 & 84.15 & 95.18 & 1.14 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Drag characteristics at the end moment of the take-off phase (EMT).  
Figure 7: Static pressure diagram at the end moment of the take-off phase (EMT) for Chinese athletes.
# Influence of Manufacturing Process Modularity on Lead Time Performances and Complexity
## 7 Case Study
### Description of Process Structures  
Process design alternative \"A\" (see Figure 8) consists of 37 machines divided into two PLs. Parts P3-P11 pass through the first production line, while parts P4, P8, P10, and P11 are finalized in the second one. Parts P1 and P2 are produced only in the second line.  
Process design alternative \"B\" (see Figure 9) contains three PLs. Parts P4, P8, P9, P10, and P11 pass through the first PL, while parts P4, P8, P10, and P11 are finalized in the second PL. Parts P1 and P2 are produced in the second PL and remaining parts are processed in PL #3.  
Process design alternative \"C\" (see Figure 10) is divided also into three PLs. The first production line processes parts P8, P9, P10, and P11, but parts P8, P10, and P11 are finalized in the second PL together with parts P1 and P2. Parts P3-P7 pass through the last production line #3.  
Process design alternative \"D\" (see Figure 11) consists of four production lines. Parts P4, P9, and P11 are processed in the first one PL, while parts P4 and P11 are finally processed in the second PL together with parts P8 and P10, which are finalized in the next line together with P1 and P2. Parts P3, P5, P6, and P7 pass through the fourth production line.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**From-to-Station** & **Alt. 1** & **Alt. 2** & **Alt. 3** & **Alt. 4** & **Alt. 5** \\ \hline W6–W10 & 53 & 41 & 36 & 46 & 41 \\ P9–W9 & 57 & 46 & 46 & 50 & 41 \\ D2–W8 & 35 & 23 & 23 & 23 & 4 \\ M3–W7 & 37 & 25 & 25 & 25 & 21 \\ N–W7 & - & - & - & - & 20 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Transport times in seconds for all the three process design alternatives.  
Figure 8: Process design alternative A.  
Process design alternative \"E\" (see Figure 12) contains six production lines. Part P4 passes firstly through the first line and then, it is finalized in the fifth PL. Parts P9 and P11 are processed in the second PL, but P11 is finalized in the fifth PL. Parts 8 and P10 are firstly produced in the third PL, but they are finalized also in the fifth PL. Parts P1 and P2 pass firstly through the fourth PL and they are finalized in the last PL. Parts P3, P5, P6, and P7 are processed only in the last production line.
# Optimizing Lattice Basis Reduction Algorithm on ARM V8 Processors
## 4 Experimental Results and Performance Analysis
### Performance Analysis
#### 4.3.5 Overall Optimization Effect of LLL_FP Algorithm  
Figure 11 shows the performance comparison between LLL_FP and the optimized LLL_FP at different scales, where the maximum speedup ratio is 1.42, the minimum speedup ratio is 1.34, and the average speedup ratio is 1.38.  
Overall, the optimized LLL_FP algorithm and its sub-methods presented in this paper outperform the LLL_FP algorithm and its sub-methods in the NTL library. The results demonstrate that the optimizations applied to the LLL_FP algorithm in this paper, including SIMD vectorization, assembly optimization, data prefetch, and loop unrolling, are effective.
# Intelligent Environment-Adaptive GNSS/INS Integrated Positioning with Factor Graph Optimization
## 2 System Architecture of Adaptive GNSS/INS Integration by FGO  
The proposed adaptive FGO (AFGO) approach integrates two sensors' inputs, including the absolute positioning from GNSS and relative positioning from INS. Figure 1 essentially shows the workflow, which contains scenarios of both the adaptive and fixed integration based on the settings of GNSS solution uncertainty. As depicted in the workflow of Figure 1, the adaptive uncertainty comes from the prediction of the trained CNN regression model, whose input features are extracted from GNSS. Combined with the FGO-based algorithm, the adaptive uncertainty AFGO is carried out for analysis.
# Development and Assessment of a 4D Printing Technique for Space Applications
## 1 Introduction
This innovative technique not only simplifies the procedural aspects, but also eliminates the need for an array of expensive equipment for analysis. Traditionally, the characterization of SMEs in polymers demands high-precision equipment, incurring substantial costs. In contrast, the 4D printing process outlined in this study offers a pragmatic alternative, rendering complex analyses more accessible and cost effective. This unique feature positions our research at the forefront of advancements in 4D printing methodologies, setting it apart from conventional approaches in this field. In response to the identified research gap, the overarching aims of this study are two-fold. Firstly, to develop a programming device designed to facilitate the 4D printing of structures constructed from SMPs, with a specific emphasis on foldable and self-opening configurations. Secondly, to utilize this device for the 4D printing of hinges crafted from PEEK, with the explicit goal of achieving a level of performance suitable for potential deployment in space applications. To realize these aims, a set of strategic objectives has been defined. The initial objective involves the iterative development of a prototype programming device, focusing on enhancing its design to optimize performance. Subsequently, a crucial step in our methodology is the execution of experiments meticulously designed to evaluate the effectiveness of 4D-printed hinges. These experiments aim to quantify and analyze the performance of the hinges, specifically assessing their ability to maintain and recover specific shapes upon activation. This comprehensive approach to our aims and objectives forms the cornerstone of our investigation, offering a systematic and methodical pathway to contribute significantly to the advancement of space technology. The implications of our research extend beyond the immediate context of spacecraft, demonstrating the versatility and broader engineering significance of self-activating hinges, with potential applications reaching into other domains.
## 3 Proposed Approach  
As stated earlier, properties like non-stationary/nonlinearity/long-term dependencies make the modeling of IFGD a truly formidable problem. It is known that the desired modeling performance cannot be achieved by employing traditional modeling methods mentioned above. To overcome this limitation, the BEMD-TCN approach, that hybridizes  
Figure 1: A schematic illustration of an IFGD process.  
BEMD and TCN, is proposed to identify the IFGD process. The method mainly involves four steps.  
Step 1: Collect measurements of limestone slurry flow and slurry pH in the reaction tank from the Continuous Emission Monitoring System (CEMS), which corresponds to the input and output signal of the IFGD process.  
Step 2: A decomposition based on BEMD is conducted with respect to both input and output of the IFGD process; the resulting subprocess that consists of IMF pairs has a less complicated frequency component, and hence are comparatively easy to identify.  
Step 3: According to the decomposed result, develop a well-structured TCN model for each subprocess and obtain the identification result.  
Step 4: Sum up the identification result for each subprocess, and generate the final identification result for the IFGD process of interest.  
Figure 2 schematically shows our approach.
# Laser Welding under Vacuum: A Review
## 2 The Research Status of Laser Welding under Vacuum
Based on the impressive results of the preliminary study, ISF of RWTH Aachen University built up a welding equipment for laser welding under vacuum on cooperation with PTR Strahltechnik GmbH A large number of process exploration tests of laser welding under vacuum were carried out on this new laser welding equipment [30; 31; 32]. The results of process tests showed that laser welding had a strong penetrating ability and a good adaptability for materials. Various materials, for example unalloyed steel, high alloyed steel, nickel-base alloy, titanium alloy and even copper alloy, were welded and achieved a deep and sound weld. In terms of the research results of laser welding under vacuum, ISF of RWTH Aachen University actively promoted this technology in the industrial field. In 2011, Institute of Joining and Welding (ifs) at TU Braunschweig started studying laser welding under vacuum on a corporation with Trumpf Laser- und Systemtechnik GmbH and Pro-beam M [33; 34]. Instead of the beam generator, a laser beam was coupled into a vacuum chamber of a former electron beam welding machine to carry out laser welding under vacuum. The influence of ambient pressure on spattering and weld quality in laser beam welding was presented. The process characteristics of laser welding at reduced ambient pressure was studied in detail. In recent years, more and more researchers have shown their interest in laser welding under vacuum. In 2014, the State Key Laboratory of Advanced Welding and Joining (AWJ) at Harbin institute of technology investigated the laser bead on plate welding of aluminum alloy under reduced pressure [35]. In 2017, the effect of ambient pressure on weld formations and the interaction between laser radiation and plasma plume were further investigated [36]. In 2015, Laboratory of Laser Processing at Lappeenranta University of Technology studied the influence of joint edge surface edge roughness and pre-set air gap on the weld quality and penetration depth in partial vacuum conditions laser beam welding [37]. In 2014, Shanghai Jiao Tong University investigated the plasma plume in fiber laser welding under subatmospheric pressure [38]. In 2016, the dynamic coupling between molten pool and metallic vapor ejection in fiber laser welding under subatmospheric pressure was further studied [39]. In 2015, Daimler AG in Germany carried out the welding experiments of 16 MnCr5 steel and ALMg3 aluminum using X-ray analysis to investigate the keyhole behavior at the reduced ambient pressure [40]. In 2016, Lawrence Livermore National Laboratory, USA, performed the study about the effect of reduced pressure on laser keyhole weld porosity and weld geometry in pure titanium and nickel [41]. Significant advantages of laser welding under vacuum or reduced pressure are attracting the attention of researchers and show great value of research and practical application. In the further 5-10 years, laser welding under vacuum will become a key issue in laser beam welding.
# Investigation of the Fluid Flow in a Large Ball Valve Designed for Natural Gas Pipelines
###### Abstract
A large-diameter ball valve can withstand high forces that develop as a consequence of the difference between the momentum before and after opening/closing. Moreover, the acting moment is high, the actuator needs time to perform the stroke, and the opening time can be at least 40 s. Different phenomena might occur during the process; therefore, to highlight the correlation between the changes in the fluid flow motion and the changes in the configuration of the solid walls that represent the boundaries of the fluid flow simulation domain, five case studies representing different positions of the ball--30\({}^{\circ}\), 45\({}^{\circ}\), 60\({}^{\circ}\), 70\({}^{\circ}\), and fully closed (90\({}^{\circ}\))--were studied. The validation of the results presented in Section 4 consisted of experimental tests on a ball valve with a 500 mm diameter and metal-metal sealing with a DPE design, similar to the digital twin model analyzed by the simulations. The results of the experimental tests confirm the high quality of the sealing that was determined and explained by analyzing the fluid flow using SolidWorks software. In the present work, the trajectories, pressure, and velocity fields inside the DN500 ball valve were studied. The scope of this article is to investigate the movement of the fluid, with a special focus on the sealing zones of the seats, where the impact of the high pressure can be significant. This paper demonstrates how the sealing zone of the seats--especially the upstream sealing seat--is most vulnerable to rapid destruction. Our results can be applied to identify adequate solutions to increase the reliability of the entire valve. This paper is organized as follows: In the first section, the importance and the actuality of the topic is introduced, and the scientific literature review is discussed. In Section 2, the methodology is described. Section 3 contains the presentation and interpretation of the results obtained using SolidWorks Flow Simulation 2023. Section 4 presents the experimental tests. The final section concludes on the effects specific to the fluid movement inside a large-diameter ball valve working with natural gas at high pressure (6.3 MPa).
# Active Electromagnetic Clutch for Crankshaft Decoupling from a Belt Drive System
Since the benefits of introducing the aforementioned clutch device have been proven, the present work proposes a novel, highly integrated crankshaft decoupling clutch. This active system is embedded inside the crankshaft pulley to avoid bulky implementations and ensure compatibility with virtually any FEAD architecture. It exploits an electromagnet that provides axial forces for decoupling. The fail-safe operation is guaranteed by return springs that ensure actuation when the functionality of the electromagnetic system is compromised. To identify the clutch state, two position-sensorless strategies are proposed and implemented from voltage and current measurements. These algorithms run in real time on dedicated hardware, which is in constant communication with the vehicle's electronic control unit. Experimental tests were carried out on the electromagnetic friction clutch of an AC compressor, providing insight into its dynamic characteristics [16]. However, to fulfill the requirement of efficiently powering the AC compressor with an EM instead of an ICE during a vehicle-stop condition, a crankshaft decoupling clutch (CDC) is required. The available literature lacks an in-depth investigation of the CDC to address this objective. Furthermore, most of the research efforts focus on frictional plate-based solutions. In contrast, our study employs a toothed clutch to facilitate integration and compatibility with existing FEAD architecture. The key contributions of this work are as follows:  
1. A novel electromagnetic clutch is presented for a FEAD architecture. In this case, the clutch helps in driving the AC compressor with EM instead of ICE during vehicle stop conditions. To estimate the clutch state, two position-sensorless techniques are also proposed. 2. Experimental tests conducted by means of a dedicated test bench demonstrate the efficacy of the proposed solution, making it a potential solution to be integrated into real vehicles. The remainder of this work is structured as follows. Section 2 describes the architecture and the mechanical layout of the system. Then, Section 3 outlines the electromagnetic model of the clutch. Section 4 presents two possible position-sensorless strategies to estimate the state of the clutch. Subsequently, Section 5 validates the functionality of the system and the proposed algorithms. Finally, in Section 6, we present our conclusions and discuss future work.