esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Materials and Methods
### Design of the Introduced CAD
#### 4.2.3 Handcrafted Descriptors Mining
DWT utilizes filter banks made up of several filters to break down images into low and high pass elements [59]. The low pass portion includes details about slowly changing image attributes, whereas the high pass part provides details about dramatic shifts in image characteristics. The coefficients obtained by applying low-pass filtering to both the rows and columns of the image are called low-low (LL). Such coefficients reflect the entire energy within photos. Whereas, if low pass filtration is imposed on the row values and high pass filtration is implemented to the column values, the resulting coefficients are named high-low HL which include the image's vertical information. While the low-high (LH) coefficients are produced by high pass filtering of rows and low pass filtering of columns that encompass the image's horizontal description. Finally, high pass filtration, including the row and column qualities yields the HH coefficients, that hold the image's diagonal description. To obtain the following stiffer scale of wavelet coefficients, decomposition was performed on sub-band LL. In the current study, the \"Haar\" wavelet function was employed, and the number of decomposition levels is 4. The fourth LL sub-band was further analyzed using GLCM and then the previous 13 features were calculated after this analysis (4 GLCM features and 9 statistical features). The Gabor wavelet (GW) transform is a widely known feature extraction methodology. The outcomes of the GW transform include both real and imaginary components. Because it can yield discriminatory details in a variety of orientations and dimensions, GW is commonly utilized in the area of medical image analysis. By converging the Gabor kernels with the image, GW sub-bands showing different levels and directions are produced [60; 61], which is its main advantage. Therefore, GW transform was used in this study to analyze pap smear images and extract textural descriptors. The number of features obtained after GW was 42.
## 3 Results and Discussion
### Surface Analysis: Contact Angle and Surface Roughness  
The CA measurements for samples S1-S3 exhibit values up to 150\({}^{\circ}\) as shown in Figure 3. Such values are higher than those measured for the clay substrate, which exhibited a value of 0\({}^{\circ}\), since the water drop was completely absorbed after 5 s. Therefore, it is of relevance to note that, after the first layer deposition of the OTS-treated SiO\({}_{2}\) NPs (sample S1), the CA value increased up to 157\({}^{\circ}\), suggesting that such a layer was efficiently deposited on the clay substrate. As a consequence, SHPho behavior was achieved, avoiding the absorption of the water drop. The corresponding CA values for samples S2 and S3 (two- and three-layer depositions) are 156\({}^{\circ}\) and 158\({}^{\circ}\), respectively.  
The 3D mapping of the surface roughness for the clay substrate and samples S1-S3 is shown in Figure 4. As expected, the surface morphology is irregular in all samples due to the intrinsic nature of clay material and its manufacturing conditions. Despite the presence of such morphological irregularities, this condition allows one to achieve an effective attachment of the OTS-teated SiO\({}_{2}\) NPs in each layer deposition. The latter is corroborated through the CA tests, since the SHPho behavior is achieved after the first layer deposition for sample S1.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Surface Area (m\({}^{2}\)/g)** & **Pore Volume (cm\({}^{3}\)/g)** \\ \hline SiO\({}_{2}\) NPs & 483.5 & 0.74 \\ OTS-treated SiO\({}_{2}\) NPs & 81.5 & 0.27 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Specific surface area and pore volume values calculated for untreated and OTS-treated SiO\({}_{2}\) NPs.  
Figure 3: (a) Contact angle values measured for clay substrate and samples S1–S3, corresponding to one-, two- and three-layer depositions of OTS-treated SiO\({}_{2}\) NPs. (b) A water drop stabilized on the surface of sample S3 exhibiting SHPho behavior.  
Figure 5 shows the roughness values retrieved from the surface morphology mappings. The corresponding Ra value obtained for the clay substrate is about 1.59 \(\upmu\)m, which is consistent with the inhomogeneous morphology exhibited in its corresponding 3D mapping. The Ra values for samples S1-S3 are 0.77 \(\upmu\)m, 0.56 \(\upmu\)m and 0.93 \(\upmu\)m, respectively. Such values are similar to one another and slightly different from the value obtained for the clay substrate, suggesting that the surface is slightly modified by the progressive coating of the OTS-treated SiO\({}_{2}\) NPs.
# Leg Trajectory Planning for Quadruped Robots with High-Speed Trot Gait
## 1 Introduction
Quadruped animals can achieve various gait patterns such as walk, trot, pronk, bound, half-bound, rotary gallop, transverse gallop, etc. [17]. Among them, the trot gait is the most widely used gait, which is very simple and effective. The duration of leg swing is always constant for both trot and gallop gait, although quadruped animals adjust their stride frequency while trotting, and adjust stride length for gallop gait [17]. Also, the leg trajectory planning is important for robots' stability with adjustable trajectories. [PERSON] et al. designed a Bezier curve based passive neural control method applied in bioinspired locomotion for decreasing the computational cost [18]. [PERSON] et al. designed a trajectory with a Nonuniform Basis Spline (NUBS) curve to effectively overcome obstacles [19]. [PERSON] et al. used properties of the Bezier curve for desirable swing-leg dynamics [11]. However, suitable gait trajectories considering energy efficiency are seldom researched. Therefore, in this paper, the motivation is to design an electrically actuated leg platform for quadruped robots with high-speed locomotion. The method of putting motors at the shoulder is adopted for reducing the leg inertia during the swing. In particular, the suitable leg structure and high-efficiency gait trajectory are analyzed and verified on the leg platform. The novel designed leg trajectory combines cosine curve, quintic curve, and hexagonal curve to minimize the maximum acceleration of legs and ensure the continuity of position, speed, and acceleration during high-speed trot gait. The efficiency is evaluated by measuring the endpoint acceleration, stability, and power consumption compared with the Bezier curve [9]. Furthermore, an optotrak sensor is used for measuring the actual foot-end trajectory of the two schemes. The sensor can track and analyze kinetics and dynamic motion in real-time, which is a more direct and precise method to measure the actual endpoint position, especially when the motor encoder has low precision. The remainder of this paper is organized as follows. Section 2 introduces the detailed design of the leg and the finite element analysis of the leg for the trade-off between the leg weight and strength. Moreover, the inverse kinematic analysis of the single leg gait and two different gait trajectory planning schemes are given. Section 3 gives the simulation result of two schemes in trajectory planning with Webots and experimental results measured with the optotrak sensor. Section 4 will discuss the simulation and experimental results. At last, the conclusion and direction of future works are given.
## 4 The QACMOR Routing Method
### Mechanisms of QEAs
#### 4.1.2 The Updating of Qubit in QEAs  
In QEAs, the quantum rotation gate updates the qubit. The following formula represents a qubit which rotates \(\theta_{i}\) degrees from the original vector, \(\left(\begin{array}{cc}\alpha_{i}^{\prime}&\beta_{i}\end{array}\right)^{T}\) to \(\left(\begin{array}{cc}\alpha_{i}^{\prime}&\beta_{i}^{\prime}\end{array} \right)^{T}\)  
\[\left[\begin{array}{c}\alpha_{i}^{\prime}\\ \beta_{i}^{\prime}\end{array}\right]=\left[\begin{array}{cc}\cos(\theta_{i} )&-\sin(\theta_{i})\\ \sin(\theta_{i})&\cos(\theta_{i})\end{array}\right]\left[\begin{array}{c} \alpha_{i}\\ \beta_{i}\end{array}\right] \tag{10}\]  
\(\theta_{i}\) is the rotation degree according to the following formula:  
\[\theta_{i}=\Delta\theta\times s(\alpha_{i},\beta_{i}) \tag{11}\]  
\[\Delta\theta=5\times\exp(-t/t_{\max}) \tag{12}\]  
In Formulas (11) and (12), \(\Delta\theta\) represents the rotation step, controlling the rotation speed; \(t\) represents the current number of iterations; and \(t_{\max}\) represents the predefined maximal times of calculation determined by the scale of the problem. The function \(s(\alpha_{i},\beta_{i})\) defines the direction:  
\[s(\alpha_{i},\beta_{i})=(d_{\rm{ibest}}/d_{\rm{inow}})(\xi_{\rm{ibest}}-\xi_{ \rm{inow}}) \tag{13}\]  
where  
\[\begin{array}{l}d_{\rm{inow}}=\beta_{\rm{inow}}/\alpha_{\rm{inow}}\\ d_{\rm{ibest}}=\beta_{\rm{ibest}}/\alpha_{\rm{ibest}}\\ \xi_{\rm{ibest}}=\arctan(\beta_{\rm{ibest}}/\alpha_{\rm{ibest}})\\ \xi_{\rm{inow}}=\arctan(\beta_{\rm{inow}}/\alpha_{\rm{inow}})\end{array} \tag{14}\]  
In Formula (14), \(\alpha_{\rm{inow}}\), \(\beta_{\rm{inow}}\), \(\alpha_{\rm{ibest}}\), \(\beta_{\rm{ibest}}\) are the probability of the \(i^{th}\) qubit of the current and optimal solution, respectively. Finally, if \(s(\alpha_{i},\beta_{i})<0\), the \(\theta_{i}\) rotates clockwise--otherwise, it rotates counterclockwise.
## 3 Results  
### Post-Stroke Patients  
The patient demographics of the combined data from R0-024 (19 patients, one measurement) and R04-041 (6 patients, two measurements) included 25 patients who had experienced either cerebral infarction (CI) or intracranial hemorrhage (ICH), distributed as follows: 12 ICH cases (48.00%) and 13 CI cases (52.00%). Patients S020 to S025 underwent two rounds of assessment, typically spaced two weeks apart, referred to as measurement A (input data for dataset A) and measurement B (input data for dataset B). The overall median time since stroke onset was 16.0 \(\pm\) 8.6 days for dataset A (R0-024 and R04-041 with the first measurement) and 19.2 \(\pm\) 13.7 days for dataset B (R02-024 and R04-041 with the second measurement).  
The demographic profile of the cohort showed a mean age of 67 \(\pm\) 12 years, with 18 males (72.00%) and 7 females (28.00%). Due to the complexity of recruitment and frequent discharge to rehabilitation facilities, patients with both dominant and non-dominant affected upper limbs were included: 12 patients had right-sided paresis (48.00%), and 13 had left-sided paresis (52.00%).  
On average, EMG signal recording for each patient in the R2-204 trial lasted 30 min, while for those participating in the R04-041 trial, the average recording time was approximately 45 min. The average FMA-UE score across both datasets A and B was 37 \(\pm\) 20, with a maximum possible score of 66 [4,6]. A detailed summary of patient characteristics is provided in Table 1.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Clinical Trial** & **Patient No.** & **Age** & **Sex** & **Stroke** & **Onset** & **FMA-UE** & **Paretic** \\  & & & & **Type** & **(Days)** & **FMA-UE** & **Extremity** \\ \hline  & S001 & 80 & M & CI & 11 & 58 & R \\  & S002 & 32 & F & CI & 11 & 50 & R \\  & S003 & 71 & M & ICH & 13 & 64 & R \\  & S004 & 52 & F & CI & 8 & 63 & L \\  & S005 & 82 & M & CI & 9 & 27 & L \\  & S006 & 81 & M & ICH & 5 & 16 & R \\  & S007 & 77 & M & CI & 9 & 60 & R \\  & S008 & 79 & F & ICH & 7 & 28 & R \\  & S009 & 65 & M & ICH & 5 & 55 & R \\ R02-204 & S010 & 67 & F & ICH & 12 & 37 & L \\ (input data for datasets A & S011 & 66 & M & CI & 13 & 15 & L \\ and B) & S011 & 66 & M & CI & 13 & 15 & L \\  & S012 & 64 & F & ICH & 33 & 35 & L \\  & S013 & 63 & M & CI & 13 & 59 & R \\  & S014 & 50 & M & CI & 19 & 22 & R \\  & S015 & 72 & F & CI & 16 & 52 & R \\  & S016 & 57 & M & ICH & 12 & 42 & L \\  & S017 & 57 & M & ICH & 18 & 8 & L \\  & S018 & 64 & M & CI & 9 & 60 & R \\  & S019 & 74 & F & CI & 12 & 9 & L \\ \hline \hline \end{tabular}
\end{table}
Table 1: Demographic and clinical characteristics of patients in datasets A and B.
## 1 Introduction
In [32] a cantilever harvester with tip mass was mounted on a supporting beam for lowering the first natural frequency of the integrated system. These concepts were further extended in [33], where all the modes of a cantilever harvester were trimmed to those of a continuous (beam-type) auxiliary structure. Experimental results showed a doubling of resonance peaks in a wide frequency band. A double-mode harvester was developed in [34]. In this case the harvester does not behave like a DVA, but a DVA composed of a mass and two helicoidal springs is used for trimming the harvester and for making possible the exploitation of two modes of vibration. A distributed-parameter model and an experiment showed the potentialities of this harvester, but helicoidal springs are not suited to integration with a harvester. A cantilever DVA, in which the spring is a small cantilever beam, is more suited to this purpose. This research focuses on piezoelectric harvesters having a multi-layer structure with one or more active layers surrounded by layers of structural, conductive, and insulating materials. In these harvesters the structural layer (steel or plastic material) can be extended and shaped to create a cantilever DVA, which is named Integrated Trimming Device (ITD). In a simple ITD the structural layer is extended to create a narrow appendix with a final widening: the narrow appendix behaves as a cantilever beam, whereas the final widening behaves as a tip mass. Many alternative designs are possible in order to shape the extension of the structural layer in such a way that a part basically behaves as a beam and another part basically behaves as a mass. In order to assess the validity of this concept, analytical calculations and experimental tests were carried out on prototypes made with a simple technology. Results in the frequency domain show that the prototypes are able to transform the original resonance peak of the harvester into a pair of new peaks, like in [30]. The former peak has lower frequency than the original peak and is used for trimming the harvester to the main source of vibrations. The latter peak makes it possible to collect a significant amount of energy at high frequency as well. This possibility is useful in the presence of periodic vibrations characterized by several harmonic components. In order to extend the analysis to more complex and realistic ITDs, a multi-physics finite element (FE) model was developed in COMSOL and validated by means of experimental results. New harvesters equipped with ITDs were designed and modeled in COMSOL extending and shaping the structural layer of a standard harvester. The potentialities of the harvesters equipped with IDTs were investigated by means of numerical simulations. Numerical results are presented in terms of the frequency response functions (FRFs) of generated voltage, generated power, stress, and strain distributions inside the piezoelectric material.
## 2 Materials and Methods
### Dataset  
#### 2.2.1 Carbon Sinks and Aerosol LiDAR Data  
This study utilized 9 orbital passes of Terrestrial Ecosystem Carbon Inventory Satellite (TECIS) altimetry data acquired over the study area between October 2022 and April 2023 to assess laser altimetry elevation accuracy. Specific information is provided in Table 2. The L2 product provides comprehensive geospatial and waveform information, including longitude, latitude, elevation, full-waveform data, optical axis monitoring images, and ancillary data for each laser footprint. In-orbit calibration of TECIS demonstrates elevation measurement accuracy better than 0.7 m and horizontal positioning precision within 6 m [27]. To minimize non-forest area bias, we employed 30 m resolution GlobeLand30 land cover data to filter laser footprints, excluding non-forest areas from analysis. The final dataset comprised 21,784 validated laser footprints within the study area.  
Figure 2: Study area and distribution of LiDAR footprints. (**a**) Map showing the location of the study area within China (left) and a detailed view of the study region (right). (**b**) Spatial distribution of CASAL footprints across the study area.
## 4 Theoretical Solution and Numerical Validation of Mechanical Parameters
### Finite Element Modeling  
ANSYS was used to establish the longitudinal analysis model of the \"segmental ring-bolt\" to verify the mechanical parameters of the longitudinal deformation of the shield tunnel. The solid186 element is used for the segmental ring, and the beam188 element is used for the longitudinal bolts, with longitudinal bolts embedded in the segmental rings. The target170 and conta174 elements are used to establish contact between the segmental rings (Figure 8a), allowing for the transmission of normal and tangential forces between the segmental rings but not axial tension. At the right of the model, a fixed boundary is applied to constrain the outer interface of the segmental ring. At the left of the model, the outer interface of the segmental ring is coupled to the center point of the segmental ring, and the axial force and bending moment are applied to the center point. Table 2 displays the parameters for the segments and bolts.  
To investigate the mesh independence, 3 cases are established for numerical analysis, with element side lengths of 0.1 m (Case 1), 0.2 m (Case 2), and 0.4 m (Case 3) for the segment  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Items** & **Elastic Modulus (GPa)** \\ \hline Segment (C50) & 34.5 \\ \hline Longitudinal bolt (M30) & 210 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Mechanical parameters of the segment and bolt.  
Figure 8: Finite element model: (**a**) Segment model; (**b**) Relationship between mesh and joint opening.  
Figure 7: Segment ring cross-section schematic.  
rings. Cases 1 and 2 result in elements on the segment thickness being at least 2 layers, whereas Case 3 results in elements on the segment thickness being 1 layer. Applying longitudinal axial forces to the model at intervals of 0.1 MN, with a maximum force of 1 MN. A small-time step size (0.05) is used for the solution, and the solution process has good stability. The system is stiff. The relationship between axial force and joint opening under different mesh partition conditions can be obtained (Figure 8b).  
As seen in Figure 8b, the joint openings of the shield tunnel are consistent across different cases. Considering both the computational efficiency of the model and the rationality of stress distribution, Case 2 is chosen for subsequent analysis.
# Study on Influence of Multi-Parameter Variation of Bladed Disk System on Vibration Characteristics
## 4 The Influence of Detuning Parameters on Bladed Disk System Is Analyzed
### Analysis on the Influence of Structural Changes of Bladed Disk System
#### 4.3.4 The Influence of Blade Loss on the Modal Frequency of the Blade Disk System  
Taking the top blade on the plane as the reference, one-third (6 pieces) of the blade were removed clockwise for the finite element modal analysis, and the modal modes and modal frequencies obtained were compared with the initial state of the bladed disk system (without weight). As shown in Figure 13, typical modes are extracted for comparative analysis. The modes 2, 3, 4, 6, 24 in the initial state of the first column of the bladed disk, and the modes 2, 3, 4, 6, 19 in the case of the second column of missing blades are similar to the mode of the initial state.  
Combined with Figures 9 and 10, Table 3, it can be concluded that when part of the blade of the bladed disk system is missing, the modal shape is generally consistent with  
Figure 13: Comparison of modes with blades missing in bladed disk system.  
the change trend of the initial state. Due to the absence of blades, the mass distribution of the bladed disk system is not uniform, resulting in the change of the corresponding modal mode, and the offset of nodal line and nodal circle is no longer symmetrical distribution. Due to the absence of blades, the mass of the dissonant bladed disk decreases significantly, leading to a significant increase in the modal frequency of the bladed disk system, especially at lower order. The blade loss causes the bladed disk system to be asymmetrical, which leads to the increase of vibration amplitude of each order. At the order 6-23, blade vibration is still dominant in the disc system, and the disk is still at rest. The loss of blades will lead to quality imbalance of the disc system and the loss of the characteristic of axial symmetry.
## 2 Design of the Dielectric-Resonator-Based Absorber  
The perspective view of each single element of the absorber is shown in Figure 1a. The side view and top view of the element are shown in Figure 1b,c, with the dimensions marked. The unit cell is periodically extended in the x and y directions with a lattice period of \(p\), forming the whole structure of the absorber, as shown in Figure 1d. Each element consists of two parts, the dielectric resonator and metal backplate. The dielectric resonator is formed with a cylindrical-shaped dielectric body and a dielectric plate, with a thickness of \(h_{s}\). The cylindrical dielectric body has a radius of \(d_{r}\) and a height of \(h_{r}\). The commercial 3D printer is used to print the whole structure. The carbon-loaded ABS material, TW-CON175 BK, provided by TorwellTechnologies (Shenzhen, China), is used as the dielectric material. The property of the material is measured and modeled, which will be discussed in detail in the next section. The copper plate is used as the metal plate, as shown in Figure 1a. In practice, a copper foil with a thickness of about 0.1 mm is bonded to the dielectric plate's backside, which will be discussed later. As the metal plate only serves the reflection plate of the absorber, the thickness of the metal plate has little effect on the performance of the absorber if its thickness is much greater than the skin depth of the electromagnetic wave. The skin depth of the copper at 2 GHz is about 0.002 mm, so the copper foil can operate well as the metal plate. The dimensions of the absorber's element are optimized using the particle swarm optimization algorithm, integrated in Computer Simulation Technology (CST) Microwave Studio to obtain the wide operating band. In the optimization process, the operating bandwidth is set as the optimization goal. In addition, the operating band of the absorber is set to cover the whole C-band (4-8 GHz) and X-band (8-12 GHz), which are widely used in the satellite communication and military applications. Through optimization, good impedance matching can be obtained between the absorber and air, resulting in the incident wave propagating to the absorber and near-unity absorption appearing over a broad bandwidth. The design diagram of the absorber is shown in Figure 1e. The adopted methodology used in each step is also given in this figure for easier understanding.  
Figure 1: (**a**) Prospective view of the element of the absorber. Each part of the element is ranged layer by layer; (**b**) Side view; and (**c**) top view of the element. The geometrical parameters are as follows: \(p\) = 23.7 mm, \(d_{r}\) = 7.85 mm, \(h_{tr}\) = 6.12 mm, \(h_{s}\) = 3.25 mm; (**d**) Schematic diagram of the whole dielectric-resonator-based ultra-broadband absorber; (**e**) Design diagram and adopted methodology for the design of the absorber.