esa-sceva/satcom-chunk-collection huggingface dataset:
# Optimizing the Quality of Service of Mobile Broadband Networks for a Dense Urban Environment
## 1 Introduction
### Key Contributions  
For financial and scientific purposes, optimization of service provision or production processes aims at providing solutions that minimize input while sufficiently attaining the required output. This study brings to light the possibility of improving the QoS by adopting a minimization technique. Furthermore, it aims at suggesting optimized KPI values within the capacity of the MNOs, which are also conveniently within recommended standard values. The specific contributions are comprehensively summarized as follows:  
1. We provide an extensive 4G LTE mapping and signal performance measurement overview in UNILAG, Ikorodu, and Oniru VI of Lagos, Nigeria. As a fast-growing economy, Lagos provides a thriving environment for adopting networking optimization. This can serve as the bedrock for improved network performance and user experience.
2. A detailed analysis and data visualization of the measured parameters has been performed using MATLAB R2021a and presented in appropriate tables and figures. The decision to use the data as obtained for the analysis makes the results obtained closer to reality than if the choice of completing missing data was adopted.
3. The relevance of adopting a multidimensional approach in the examination of the QoS and QoE of 4G LTE through metrics such as RSRP, RSRQ, SINR, throughput downlink (DL), and uplink (UL), rather than using a single parameter, will also be tested.
4. The specific optimized value range for metrics such as the RSRP, RSRQ, and SINR are suggested, while recommendations for implementing the optimized values for all the test environments are made in line with the specific challenges in the areas.
# NFT Technology for Enhanced Global Digital Registers: A Novel Approach to Tokenization
## 8 Experimental Evaluation
### Experimental Results
#### 8.5.1 Performance Metrics  
Table 3 summarizes the key performance metrics obtained from our experiments.  
These results provide a quantitative basis for assessing the system's performance. The throughput of 33.22 transactions per second indicates a robust capacity for handling  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Metric** & **Value** & **Unit** \\ \hline Throughput & 33.22 & Transactions per second \\ \hline Latency & 26 & Milliseconds \\ \hline Gas consumption (register) & 126,276 & Gas units \\ \hline Function execution Time & 14 & Milliseconds \\ \hline Batch registration (5 items) & 102 & Milliseconds \\ \hline \hline \end{tabular}
\end{table}
Table 3: Performance Metrics of the GlobalDigitalRegistry smart contract.  
registration operations, while the low latency of 26 ms suggests responsive system behavior. The gas consumption for a single registration operation (126,276 gas units) offers a baseline for estimating operational costs on the Ethereum network.
# Seismic Response of Shield Tunnel with Double-Layer Lining
## 3 Finite Element Model of Shield Tunnel
### The Numerical Model  
A three-dimensional finite element analysis model is established using Abaqus 2020 software. The dimensions of the model are length \(\times\) width \(\times\) height = 60 m \(\times\) 60 m \(\times\) 200 m, with the burial depth of the shield tunnel being 25 m. The segmental lining is modeled using an equivalent homogeneous circular ring model, which considers the weakening effect of the segmental joints on the lateral stiffness of the segmental rings by using a reduction factor of 0.8 ([PERSON] et al., 2018). A secondary lining is applied on the inner side of the segmental lining (Figure 2). Both the stratum and the shield tunnel adopt 3D stress-reduced integration elements (Semens, Plano, TX, USA).  
Figure 1: The schematic diagram of the segmental ring.  
The geological parameters of the numerical model are selected according to the \"Design Specification for the Shiziyang Tunnel of the Guangzhou-Shenzhen-Hong Kong Passenger Dedicated Line\" [27]. The segmental lining and secondary lining are modeled with concrete under a linear elastic constitutive model, with material parameters shown in Table 1.  
This model represents an overlapped double-layer lining structure, where both axial force and shear force can be transferred between the segmental ring and the secondary lining. Normal contact is adopted between the segmental lining and the secondary lining, while tangential contact utilizes frictional contact with a friction coefficient of 0.6 [13,28].
## 3 Research of the Path Tracking Control Strategy
### Design of Closed-Loop System of Tracking Controller  
In engineering application, the more complex the control algorithm used in the controller is, the larger the amount of calculation and the worse the real-time performance will be. Automatic parking needs to accurately track the ideal path in a restricted area, therefore, a high level in terms of real time is required. Usually, it has to complete the planning of an upper-level decision within 60 ms system cycle. In order to reduce the complexity of the control algorithm, and meet the requirements of engineering applications, the tracking controller system of the kinematic model is transformed into a cascade system, including vehicle position control and vehicle body attitude control, as shown in Figure 9, where the inner-loop refers to the vehicle body attitude subsystem, and the outer-loop represents the vehicle position subsystem. When the inner-loop received the command signal  
Figure 8: Simplified Path Tracking Model.  
generated by the outer-loop, tracking \(\theta_{d}\) is achieved through sliding mode control law (\(\theta_{d}\) refers to the ideal driving direction angle).
# Solar Radiation Pressure Models for BeiDou-3 I2-S Satellite: Comparison and Augmentation
## 1 Introduction
Besides, the adjustable box-wing model (ABW) can also reduce this error, because the model is derived from the physical theory, and can fit real tracking data well, as shown for QZSS Michibiki satellite [11]. In this study, the performances of the above mentioned ECOM1, ECOM2, and ABW models for BeiDou-3 I2-S will be compared and analyzed. In addition, the a priori SRP models to augment the ECOM1 model will be derived based on analytical cuboid box model and empirically spectra analysis. We prefer the a priori model, as the additionally introduced higher-order harmonics in ECOM2 may increase the sensitivity to other modeling errors and result in a slightly degraded performance during certain mission phase. For ABW model, problems of observability likewise affect its use, as there are quite strong correlations between the estimation parameters. Following short descriptions of the yaw attitude and body structure of BeiDou-3 I2-S satellite, the ECOM1 and ECOM2 model, as well as the ABW and cuboid models will be presented in Section 2. In Section 3, the comparison and analysis of performance of these models for BeiDou-3 I2-S will be presented. Based on these results, an empirical a priori model to augment the ECOM1 will be established by fitting the reconstructed SRP acceleration to the predetermined formulae after spectral density analysis with fast Fourier transformation (FFT) approach in Section 4. In addition, the parameters for the cuboid model will also be presented. Afterwards, the developed models will be validated in Section 5. Finally, this study is summarized and concluded in Section 6.
# Research on Clustering-Based Fault Diagnosis during ROV Hovering Control
## 3 Configuration of ROV  
### Hardware System  
For experimental verification of the proposed FD, an ROV was constructed with dimensions of 560 \(\times\) 435 \(\times\) 290 mm\({}^{3}\) (L \(\times\) W \(\times\) H), as shown in Figure 10. The design was developed using SolidWorks (2023) to ensure that the center of gravity and buoyancy coincided. To prevent this, the exterior shell was composed of aluminum, which is resistant to corrosion. The ROV comprised a main pressure cylinder for housing sensors and electronics, an auxiliary pressure vessel for power supply batteries, and eight thrusters. Four vertical thrusters controlled the roll, pitch, and heave motions, and four horizontal thrusters controlled the surge, sway, and yaw motions.  
Figure 10: Manufactured ROV system and 2D schematics.  
Figure 9: ROV system schematic. Two main processes are followed: hovering control and FD.
###### Abstract  
The state-of-the-art technology of X-ray microcalorimeters based on superconducting transition-edge sensors (TESs), for applications in astrophysics and particle physics, is reviewed. We will show the advance in understanding the detector physics and describe the recent breakthroughs in the TES design that are opening the way towards the fabrication and the read-out of very large arrays of pixels with unprecedented energy resolution. The most challenging low temperature instruments for space- and ground-base experiments will be described.  
superconducting detectors; X-ray microcalorimeters; low temperature detectors; neutrino mass experiments; detectors for particle physics; solar axions; B-mode polarization experiments; X-ray observatory; space instruments for astrophysics +
Footnote †: journal: Applied Sciences  
1  
of the available read-out technology. The sensor and the read-out are influencing each other and, when aiming to the highest level of performance, they cannot be developed separately. For these reasons, it is important to give an overview of the fundamental physical processes affecting the TES resistive transition and the noise, with the focus on the interaction between sensors and the read-out system. We will describe the major breakthrough, after the last review [15], on the TES design optimization, which opened the way to the read-out of large arrays of pixels.  
This paper is organized as follows. In Section 2, we present the basic theory of TES microcalorimeters and discuss the physics of the resistive transition and the major noise sources. We will describe as well the generalized system of equations that can be solved to perform realistic simulations of the dynamical response of the TES and its read-out circuit. Thanks to the available computational power of modern computers, the end-to-end simulation will become an essential tool to guide the development and the calibration of the very complex instruments under construction.  
In Section 3, the challenges in the fabrication of the sensors, absorbers, and thermal links in a large array are described. The vivid research work of the past few years in the improvement of the performance and uniformity of the TES X-ray calorimeters, both for the dc and ac voltage biased read-out, is covered in Section 4. Most of the development in this area is driven by the stringent requirements from the X-ray Integral Field Unit (X-IFU) [16], which is one of the two instruments of the Athena astrophysics space mission [2] approved by ESA in the Cosmic Vision 2015-2025 Science Programme.  
In Section 5, we summarize the recent progress in the multiplexing demonstration of a large number of pixels with high energy resolution. Finally, in Section 6 we will describe several ground- and space-based applications where the core technology is based on large arrays of TES X-ray microcalorimeters.
## 6 Discussion
### Discussion for Scenario 3: Return  
In the return scenario, the cobot assists the worker by returning items such as tools and parts to their designated locations. Thus, for the return scenario accurate placement and efficient communication are essential. The proposed framework ensures a tidy and efficient workspace while allowing workers to focus on core tasks, improving overall productivity. The implementation discussion on hardware and software is as follows.  
Hardware:  
For the return scenario, cobots should be capable of handling higher payloads for larger tools. An example of such a cobot is the FANUC CRX-20 iA/L. The gripping tool of the end effector has to handle varied tool types and sizes. Robotiq Hand-E grippers offer reliable handling of varied tool types and sizes. Finally, the return scenario would require proximity and touch sensors for safe operations in shared workspaces.  
Software:  
The return scenario requires a Storage Management system. This system must hold an updated list of all tools, parts, and equipment (items). For each item, the system keepsits unique ID, type, weight, dimensions, designated storage locations, and the current location. This Storage Management system should be implemented using a relational database-driven storage system that needs to handle frequent real-time updates (of current tool location) and quick queries mostly related to the item's location or its predefined location/s. SQL-based systems provide good alternative solutions. For example, MySQL, PostgreSQL, or Microsoft SQL Server are all viable solutions. For the return scenario, path planning is also required: defining and executing optimal return paths may use MoveIt or the MATLAB Robotics Toolbox. Finally, in case something goes wrong, or if further input is needed, real-time communication becomes important and could be achieved by interactive vocal guidance for rapid and clear instructions using a voice recognition system such as Azure Speech Service.
## 4 Discussion
### Limitations and Future Research Directions  
Although the novel coupling of the importance and vulnerability of Nature's Contributions to People (NCPs) into the ecological conservation region for improving human well-being has been identified, our study still has several limitations. First, due to the limitations of the NCPs index, only three types of NCPs were estimated in this study. This exclusion of the remaining fifteen types introduces uncertainty into the NCPs assessment [17]. A more comprehensive evaluation, including all eighteen NCP types, would likely provide a more accurate and holistic understanding of the conservation needs and benefits. Second, the identification of priority conservation areas for NCPs was not conducted using a holistic approach. This could result in an inadequate representation of local social and ecological processes [10]. For a more complete analysis, it is crucial to incorporate a wider range of ecological and social data, ensuring that the identified conservation areas effectively address both local ecological conditions and human needs. Third, this study only considered three socio-climatic scenario changes within the SSP2 shared pathway. This limited scope may lead to either underestimation or overestimation of socio-climatic indices. To mitigate this, future studies should incorporate a broader range of socio-climatic scenarios. This would help in capturing a more accurate spectrum of potential future conditions and their impacts on NCPs.  
To address these shortcomings, future research should consider other NCPs, including non-material contributions, even if the NCPs selected in this study are preferred or deemed important by local stakeholders [29]. Additionally, integrating ensemble means of socio-climatic pathways, along with climate change data and local demand, would more accurately identify priority conservation areas for NCPs. This comprehensive approachwould provide a more robust framework for improving human well-being through effective ecological conservation.
# Computationally Efficient PM Power Loss Mapping for
## 5 Modification in the Full Operational Envelope
### The Influence of Temperature on the Conductivity of PMs  
The relationship between the conductivity of NdFeB and the temperature is shown in formula in Equation (11), that is, conductivity is inversely proportional to the quadratic function of temperature. Figure 7 shows the relationship between the conductivity of NdFeB in this paper and temperature:  
\[\sigma_{NTP}=\sigma_{NTP0}\frac{1}{\left(1+\beta_{1}(T-T_{0})+\beta_{2}(T-T_{0 })^{2}\right)} \tag{11}\]  
where \(\sigma_{NTP0}\) is the conductivity when the temperature is \(T_{0}\) and \(\beta_{1}\) and \(\beta_{2}\) are the correction coefficients for the conductivity of the PM.  
Figure 6: The relationship between operating temperatures and PM losses caused by the slotting effect calculated by the formula in Equation (10) and the FEA. (**a**) n = 600 rpm. (**b**) n = 1039 rpm.  
According to [15; 16; 17], ignoring some of the less influential factors, the entire PM loss is proportional to conductivity. It is assumed that when the temperature changes, the internal resistivity of the PM changes isotropically. The computationally efficient method of PM loss, considering resistance change, can be expressed as  
\[=\frac{P_{PM-AL}=\frac{\rho_{NP}}{\rho_{NTP}}(P_{PM-SL}+P_{PM-EL})}{ \big{(}1+\beta_{1}(T-T_{0})+\beta_{2}(T-T_{0})^{2}\big{)}(P_{PM-SL}(n^{2},i_{d},B_{r})+P_{PM-EL}(n,N,M)\big{)}} \tag{12}\]  
where  
\[P_{PM-SL}\Big{(}n^{2},i_{d},B_{r}\Big{)}=\bigg{(}{a_{i}}^{2}+{b_{i}}^{2}+ci_{d }\bigg{(}\frac{B_{r}}{B_{r0}}\bigg{)}+d\bigg{(}\frac{B_{r}}{B_{r0}}\bigg{)}^{2 }\bigg{)}\bigg{(}\frac{n}{n_{w}}\bigg{)}^{2} \tag{13}\]  
Figure 8 shows the relationship between operating temperatures and the results calculated by the fitting formula in Equation (12) and the finite element calculation. Here, the effects of both PM remanence and conductivity changes are considered. Figure 8a shows that when the q-axis current is large, as the temperature increases, a smaller error occurs. The analysis reason is the interaction of the q-axis current armature reaction and the PM remanence change and the saturation of the stator core. Therefore, the fitting formula in Equation (12) can calculate the PM loss at different temperatures.  
Figure 7: The relationship between electrical conductivity and temperature of NdFeB (\(\beta_{1}=-1.102\times 10^{-3}K^{-1}\), \(\beta_{2}=-3.038\times 10^{-6}K^{-1}\)).
## 4 Simulation and Discussion
Figure 8: When \(m^{2}=0.3\), i.e., under weak scintillation (**a**) average BER of BPSK, \(L\)-PPM and \(L\)-PPM–BPSK–SIM against average SNR; (**b**) average BER of \(L\)-PPM–BPSK–SIM with various \(L\) on the hybrid RF/FSO system and FSO system against the average SNR. Figure 10 describes the relationship between the average channel capacity and SNR. Here we simply consider the effects of the scintillation index and pointing error. As shown in Figure 10, the average channel capacity decreases with the increase of the scintillation index. The reason is that solar scintillation leads to irregular fluctuation of signal amplitude, which produces changes in the power of the received signal. The pointing error also has a certain impact on the average channel capacity. In Figure 10, when the scintillation index is fixed, the larger the pointing error parameter is, the larger the system capacity will be. For example, for \(\text{SNR}=15\) dB, \(m^{2}=0.3\), when \(\xi=1\), the average capacity is 3.59, and when \(\xi=10\), the average capacity is 4.22. Furthermore, the average channel capacity performance also follows the tendency that the larger the pointing error parameter, the smaller the impact on the performance of the system. Figure 10: Average channel capacity against average SNR per hop (**a**) for a different scintillation index; (**b**) for different pointing error parameters. Figure 9: Under coronal turbulence, the average BER performance of the hybrid RF/FSO system against (**a**) outer scale, (**b**) spectral index, (**c**) wavelength, (**d**) density fluctuation factors.
###### Abstract  
The aim of this study is to develop a fast data fusion method for recognizing metro-to-bus transfer trips based on combined data from smart cards and a GPS system. The method is intended to establish station- and time-specific elapsed time thresholds for overcoming the limitations of one-size-fits-all criterion which is not sufficiently convincing for different transfer pairs and personal characteristics. Firstly, a data fusion method with bus smart card data and GPS data is proposed to supplement absent bus boarding information in the smart card data. Then, a model for identifying metro-to-bus interchange trips is derived based on two rules about maximal allowable transfer distance and elapsed transfer time threshold. Finally, in tests that used half-monthly field smart card data and GPS data from Shenzhen, China, the results recognized by the proposed method were more consistent with the actual surveyed group transfer time with a P value of 0.17 determined by Mann-Whitney U test. The comparison analysis showed that the proposed method can be widely applied to successfully identify and interpret metro-to-bus interchange behavior beyond a static transfer time threshold of 30 min.  
smart card data; GPS data; data fusion; metro-to-bus transfer; behavior identification +
Footnote †: journal: Applied Sciences
# Optimal Collision-Free Grip Planning for Biped Climbing Robots in Complex Truss Environment
## 2 Problem Statement  
### Global Path Planning and Feasible Routes  
In our framework, the crucial point of global path planning is to provide global guidance for the subsequent processes, i.e., grip planning and single-step motion planning. It concentrates on the fast determination of all feasible routes, \(\Gamma\). The distinguishing merit is that it largely narrows down the searching space to a limited number of members, and thus largely increases the searching efficiency.  
As a global guidance for BiCRs, a feasible route, \(\Gamma_{i}\), should indicate the entire climbing path with the member sequence \(\mathfrak{M}\), the gripping orientations \({}^{W}\mathbf{R}\) on the members, and the operational regions \(\mathfrak{R}_{t}\) for transitions. Figure 2 shows us an illustration of one feasible route in a scene consisting of 7 members, taken from [27]. In the scene, each member is described in the world frame \(\{W\}\) as  
\[{}^{W}\mathbf{P}={}^{W}\mathbf{P}_{0}+t\cdot{}^{W}\mathbf{P}_{dir},\ \ 0\leq t\leq L_{mem}, \tag{1}\]  
where \({}^{W}\mathbf{P}_{0}\), \({}^{W}\mathbf{P}_{dir}\) and \(L_{mem}\) are the reference point, the direction unit vector and the length of the member, respectively. While \(t\) is a scale, which can be used to specify the gripping position on the member. For the convenience of expression and understanding, \({}^{j}x\) is denoted as a grip position on the \(j\)-th member from where a transition begins (the takeoff segment) and \({}^{j}y\) on the same member to where a transition ends (the landing segment). That is to say, \({}^{j}x\) and \({}^{j}y\) are also scales the same as \(t\). Based on this notation, the operational regions for transiting from \(j\)-th member to \((j+1)\)-th member are the set of \({}^{j}x\) and \({}^{j+1}y\), i.e.,  
\[\left\{\begin{array}{l}{}^{j}x\in[{}^{j}\underline{x},\ {}^{j}\underline{x}]\\ {}^{j+1}y\in[{}^{j+1}\underline{y},\ {}^{j+1}\underline{y}]\end{array}\right., \tag{2}\]  
where the boundaries are computed by the transition analyzer during global path planning. We proved that \({}^{j+1}y\) and \({}^{j}x\) are linear for BiCRs like Climbot with planar configurations in [27]. Therefore, their relationship can be written as  
\[{}^{j+1}y=\sigma^{j}x+\delta, \tag{3}\]  
where \(\sigma\) and \(\delta\) are constants. In other words, the gripping points within the operational regions for transitions are one-to-one mapping.  
Figure 2: An illustration of a feasible route. Green and red spheres in the figure stand for the initial position and the destination, respectively. Nearby numbers indicate the sequence of transitions to be performed along the route.