esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Results and Discussion
### Distribution of Residual Oil in Heterogeneous Porous Media
#### 3.1.3 Residual Oil Distribution under Different Wall Wetting Degree  
The comprehensive characteristics of rock-fluid in the wettability of soil particles depend on the interfacial tension between rock-fluid and fluid and the adsorption of polar substances on the rock surface. Study on wall wettability plays an important role in reducing displacement residual oil. The simulation shows that under different wall wettability conditions, the residual oil in the model will change. Taking chip 1 as an example, the distribution of residual oil was discussed when the wall contact angles were \(\pi/6\) rad, \(\pi/3\) rad, \(\pi/2\) rad, \(2\pi/3\) rad and \(5\pi/6\) rad. In the above wall, the contact angle of \(\pi/6\) rad represents the most hydrophilic of the wall, and the contact angle of \(5\pi/6\) rad represents the most lipophilic of the wall. Figure 6 shows the oil volume fraction variation at different time under different wall wettability.  
At a wall contact angle of 5 pi/6 rad, the water phase displaces the oil phase to form an oil film on the particles in the hyperpermeable zone, and at 0.2 min the water phase breaks  
Figure 6: Oil volume fraction variation at a contact angle of (From top to bottom: \(5\pi/6\); \(2\pi/3\); \(\pi/2\); \(\pi/3\); \(\pi/6\); from left to right: 0 min; 0.1 min; 0.2 min; 1 min). The scale bar is 1 mm.  
through the hyperpermeable zone to form one of the narrowest dominant channels with the smallest ripple area and the largest amount of residual oil. As the wall contact angle decreases, the time required for the water phase to break through the hyperpermeable zone increases and the amount of residual oil decreases. When the wall surface changes from oleophilic to hydrophilic, the oil phase in the low permeable zone begins to transport and the amount of residual oil is further reduced. When the wall contact angle is pi/6, the wall surface is most hydrophilic and the water phase invades from both the hyper- and hypo-permeable zones at the same time, the front end of the water phase repulsion is smoother and the residual oil in the hyper-permeable zone has been completely removed when the proposed steady state is reached, and the overall residual oil is minimal.  
The variation of residual oil in the high and low permeable zones with time under different wall wettability of chip 1 is shown in Figure 7. With the continuous increase of wall wettability, the residual oil in the high and low permeable zones of chip 1 decreases. The wettability of the wall is different, and the distribution of oil and water in the throat is also different. Due to the interaction of interfacial tension, the wetting phase is always attached to the wall, and wants to occupy a smaller gap corner and push the non-wetting phase to the middle of the throat. Therefore, after the water flooding of the lipophilic wall through the pore throat, a large number of residual oil is left. With the continuous increase of wall wettability, the oil displacement effect will be increasingly better.
# Analysis and Design of Rateless Two-way Relay Networks Based on a Multiply-and-Forward Scheme
## 4 Fountain-coded MF-TWRN
### Optimization Design  
In order to successfully decode the BPSK-modulated SLT codes in the noisy channel, the mean value of LLR messages should increase from iteration to iteration during BP decoding. Obviously, it is necessary to satisfy this condition for different received SNRs so that SLT-coded MF-TWRN could achieve good performance in the flat Rayleigh fading channel. Assume \(\mathbf{\Gamma}\) denotes the set of received SNRs in MF-TWRN. For \(\forall\gamma_{0}\in\mathbf{\Gamma}\), the aforementioned condition can be described as  
\[\varepsilon\sum_{d=1}^{d_{c}}d\Omega_{d}f_{d}\Bigl{(}\mu_{Q}^{(l-1)}\Bigr{)}+2 \gamma_{0}>\mu_{Q}^{(l-1)} \tag{63}\]where \(\mu_{Q}^{(l)}\) represents the mean of LLR messages in the \(l-\)th iteration, and  
\[f_{d}\Big{(}\mu_{Q}^{(l-1)}\Big{)}=\varphi^{-1}\Bigg{(}1-(1-\varphi(2\gamma_{0}) )\Big{(}1-\varphi\Big{(}\mu_{Q}^{(l-1)}\Big{)}\Big{)}^{d-1}\Bigg{)} \tag{64}\]  
where  
\[\varphi(x)=\begin{cases}\exp(-0.4527x^{0.86}+0.0218),&0<x<10\\ \sqrt{\frac{\pi}{x}}\big{(}1-\frac{10}{7x}\big{)}\exp\Bigl{(}-\frac{x}{4}\Big{)},&x\geq 10\end{cases} \tag{65}\]  
Inspired by the optimization model we have proposed for BPSK-modulated SLT codes in the BIAWGN channel [24], the optimization model of degree distribution for SLT-coded MF-TWRN in the flat Rayleigh fading channel is proposed in what follows, aiming at minimizing the average degree with main constraints introduced by (50) and (63):  
\[\begin{array}{l}\min\sum\limits_{d=1}^{d_{c}}d\Omega_{d}\\ \text{s.t. }\varepsilon_{0}\sum\limits_{d=1}^{d_{c}}d\Omega_{d}f_{d}(\mu_{i})+2 \gamma_{0}>\mu_{i},i=1,\ldots,N,\forall\gamma_{0}\in\boldsymbol{\Gamma}\\ P_{\text{Ib,MF}}\leq y_{0}\\ \sum\limits_{d=1}^{d_{c}}\Omega_{d}=1\\ \Omega_{d}\geq 0,d=1,\ldots,d_{c}\end{array} \tag{66}\]  
where \(\mu_{i}(i=1,\ldots,N)\) represents the \(N\) equidistant points in the interval \((0,\mu_{0}]\). The values of \(d_{c}\), \(\varepsilon_{0}\), \(\mu_{0}\), \(y_{0}\) and \(N\) should be determined in advance, serving as control variables. For the practical use of this optimization model, discretization is generally performed on the set of received SNR, and we make use of a quasi-Newton method to iterate toward a solution of optimized degree distribution.
## 3 Experimental Results and Analysis  
### Strength  
The compressive and flexural strength results of the specimen are presented in Figure 8 to indicate the properties of raw materials, indicating that the compressive and flexural strengths increase with increasing age. The compressive strengths were estimated to be 15.0 MPa (7 days of age), 23.0 MPa (14 days), and 29.0 MPa (28 days), and the flexural strengths were 4.5 MPa (7 days), 5.8 MPa (14 days), and 7.3 MPa (28 days). When the age exceeded 14 days, the compressive strength criterion (16.0 MPa) for porous revetment blocks in SPS-KIC0001-0703 [22] and the flexural strength criterion (5.0 MPa) for water-permeable blocks in KS F 4419 [23] are satisfied. In particular, a flexural strength exceeding 7.3 MPa is developed in 28 days. This value appears to be high considering that sidewalk blocks, as red clay water-permeable block products, can be easily damaged in the transport process and on-site installation stage after forming with the existing flexural strength criterion.
### Aim of the Article  
Due to the aforementioned advantages and the importance of balance and gait in ADLs, a wide range of rehabilitation robots has been developed during the last few decades [36]. However, the current literature on rehabilitation robotics often provides limited information about the characteristics of available prototypes, and this lack of information makes the classification of robotic devices challenging [37]. Some review articles attempted to pave the way toward a standard classification [38], but the proposed classifications are focused on gait rehabilitation systems and do not consider those devices for balance rehabilitation [39; 40]. Hence, there is a need to provide a classification that takes into account both balance and gait rehabilitation devices.  
From the available reviews and studies on lower-limb rehabilitation robots [41; 42], four general types of rehabilitation devices can be distinguished: treadmill-based robots, wearable exoskeletons, end effectors, and overground rehabilitation robots. Specific reviews of treadmill-based robots [43], wearable exoskeletons [44], and overground rehabilitation robots [45] can be found in the literature. In contrast, the information available about end effectors for gait and balance rehabilitation is scarce, too general (i.e., limited to a few commercially available end effectors and well-known prototypes), and mainly focused on gait rehabilitation [46]. Therefore, there exists an information gap, and different end effector-based robots that could be promising for gait and balance rehabilitation are scattered in the literature.  
Compared to other types of rehabilitation robots, end effectors present some advantages (e.g., easily adjustable to different patients, reduced setup time, and promoting active patient participation), and different studies highlighted their suitability for rehabilitation [47]. Thus, it may be interesting for the scientific community to carry out a thorough review to identify and analyze the end effectors covered in the literature.  
Consequently, this article has two main objectives: to propose a classification of rehabilitation robots for gait and balance functions and to provide a comprehensive overview of end effector robots in the literature. The key points of these two objectives are shown in Figure 1.  
The article is organized as follows. In Section 2, the currently available rehabilitation devices for gait and balance training are explained and classified. As seen in Figure 1, we classified them into five general groups depending on the type of rehabilitation workspace (i.e., fixed frame or overground). Section 3 highlights the advantages of the end effector-based robots, presents all the identified designs, and discusses future directions pursue to tackle the shortcomings of current end effectors. In total, 55 end effectors were identified (16 commercial devices and 39 prototypes), and we analyzed their most relevant features  
Figure 1: The two main objectives of this article and their corresponding key points.  
from a mechanical point of view. Finally, in Section 4, the conclusions of this review article are drawn.
# IEC-61108-7 SBAS Standard for Shipborne Receivers: Preliminary Testing Validation Activities +
###### Abstract
Part 7 of the IEC 61108 standard focuses on the minimum performance required by shipborne receivers using SBAS L1 signals to be compliant with the performance specified within IMO Resolution A.1046(27). Apart from the minimum performance requirements, the standard specifies the testing methods and a full set of scenarios with their pass/fail criteria. The European Satellite Services Provider (ESSP) provided support to the European Union Agency for the Space Programme (EUSPA) for the whole IEC 61108-7 [11] standardization process. During the development of the standard, a fundamental building block was a feasibility analysis of the tests defined in the standard. The objective of this assessment was not to certify the compliance of the devices but to assess the validity and consistency of the requirements set out in the standard. Such an assessment is needed to make sure that the implementation of the test scenarios and the assessment of the pass/fail criteria can be made by certification laboratories that choose to build test setups according to IEC 61108-7. For the assessment, a comprehensive test campaign was carried out in a joint effort by ESSP and the Joint Research Centre (JRC) under the coordination of EUSPA. During the testing campaign, the whole suite of tests described in [11] was executed. The paper presents the preliminary testing validation activities carried out, with a specific focus on the setup design and realization. The remainder of the paper is organized as follows: in Section 2, the general setup is described; the setup for specific test cases (TCs) is presented in Section 3, together with sample results; and finally, Section 4 concludes the paper.
## 2 Structural Features and Methodology
### Computational Details
#### 2.3.3 Density Functionals  
Nine different XC functionals that performed well in previous studies of similar systems or belonged to this category of systems were tested with the Na-dominant clinoptiloite [42; 43; 44]. The first choice was PBE-D3. PBE-D3 with Becke and Johnson damping [38; 45] was also included in the comparison since it was claimed that the damping function is one of the weak points in the DFT-D methods. The revised version of PBE, the so-called'revPBE' with dispersive interactions, was also included since it was claimed to improve atomic total energies over the original PBE by a factor of 10 [46; 47]. The meta-GGA performance is similar to that of the PBE; therefore, it was worth including it in the comparison with the dispersion correction TPSS-D3 [35; 48]. PBEsol [35; 49], PBE for solids, with dispersion correction was included in the comparison since it is believed this halves the error of the meta-GGA, TPSS, regarding the lattice constants. The B97-D3 functional, another density functional included in the comparison, is known to be one of the most accurate general-purpose GGAs, as reported by [PERSON] et al. [35; 40].  
Additionally, it was worth exploring the van der Waals density functionals, such as optB86b-vdW [50; 51] and rev-vdW-DF2 [52; 53], for various reasons, notably because they are directly based on the electronic density, unlike the previously mentioned dispersion methods, which depend on geometry. The so-called optB86b-vdW usually provides errors in the range between the PBE and PBEsol errors. The rev-vdW-DF2 is based on the second version of the vdW-DF2 nonlocal correlation term, to be used with an exchange functional proposed by [PERSON] (B86b) [54], but with improvements regarding the gradient expansion within the limits of slowly varying densities. This is supposed to provide a better description of a broad variety of systems. Bayesian error estimation functional with van der Waals (BEEF-vdW) [52; 55], a semi-empirical density functional and a semi-local approximation with an extra nonlocal correlation term that utilizes a machine learning approach and focuses on surface modeling, was also included in the study.
# Synthetized Multilanguage OCR Using CRNN and SVTR Models for Realtime Collaborative Tools
## 2 Novelty of the Approach  
In this study, we employ synthetic, multilingual training convolutional recurrent neural networks (CRNN) and patch-wise image tokenization framework (SVTR) model architectures [25] for ML-based OCR engines [14] to (1) test the possibility of custom-generated multilanguage recognition and (2) increase the accuracy and efficiency of OCR.  
Mixing Convolutional Neural Networks (CNNs) with Recurrent Neural Networks (RNNs) enables the CRNN kind of OCR engine to recognize text in images. CNN retrieves features from the input image, while RNN models the sequential dependencies between characters in the text. CRNNs effectively recognize text in various contexts, including font sizes, font styles, and orientations. They can also handle many lines of text in an image and recognize scene text accurately.  
SVTR is an advanced OCR engine that recognizes text in images by using a combination of deep learning and traditional image processing techniques. The SVTR architectures can recognize scene text in photographs with changing lighting, orientation, and skew. In addition, it has an attention mechanism that allows the network to focus on the most important visual components, hence boosting the noise and distortion resistance of the model [8].  
Both CRNN and SVTR offer innovative features in comparison to conventional OCR engines. The advantages include the following: (i) CRNN can recognize texts of various font styles, sizes, and orientations, as well as several lines of text in an image, and is effective at scene text recognition, (ii) SVTR is resistant to noise and distortion due to the attention mechanism it employs to focus on critical portions of an image and can handle scene text in images, (iii) SVTR and CRNN are deep learning-based models that learn from complicated data correlations between the input image attributes and the output text, making them more effective than conventional algorithms, (iv) CRNN and SVTR are more efficient than conventional OCR engines since they can run on parallel systems, such as Graphics Processing Units (GPU), and (v) CRNN and SVTR architectures are adaptive and can be improved with additional training data.  
It is crucial to note that OCR systems are complex and that the architecture you choose will rely on the particulars of the problem you are attempting to address. Each architecture has benefits and drawbacks, and the ideal solution will depend on the nature of the problem, the amount and quality of the data, and other factors [26]. In our research, we use and fine-tune CRNN and SVTR models with a PaddleOCR [27] framework.
## 1 Introduction  
Low divergence and a small spot light beam are essential for the displacement measurements made with a position sensitivity detector (PSD) [1]. PSD-based beam displacement measurements are important for various uses, including the atomic force microscope, the proximity exposure tool, the optical pickup head, and the Goos-Hanchen effect [2; 3; 4; 5]. Incidentally, phase-interrogation due to optical length differences between the reference and sensing paths was proposed for displacement measurements in various interferometers [6; 7]. The transformation between the incident angle and the displacement variations are made reversible using the cylindrical and object lenses [8; 9]. The displacement of the probe light was converted to the propagation angle change through a prompt transducer. The angle variations can be characterized by an optical angle sensor. Surface plasmon resonance (SPR) and total internal reflection (TIR) sensors have been successfully demonstrated to measure the angle changes in a phase-interrogation heterodyne interferometer [8; 9; 10].  
In optical metrology, birefringent materials have been widely utilized in the design of sensing transducers, particularly in angle, refractive index, spectra, and bio reaction sensors [11; 12; 13; 14; 15; 16]. The phase delay between two orthogonal polarizations (s-and p-wave) is dependent on the incident angle, birefringence, relative refractive index, and wavelength. A prism with a birefringent calcite plate attached was evaluated based upon optical angle measurement [11]. The birefringent plate immersed in a liquid medium has been proposed for the optical angle and concentration sensors in our previous works [12; 13; 14]. To overcome the induced distortion of a large light beam being refracted on a curved surface, light beams with low divergence and a small spot are essential for improving measurement sensitivity; in this study, a guided-wave beam (GWB) is proposed to fulfill these requirements. A cylindrical lens with a potassium titanyl phosphate (KTP) plate attached was fabricated as a compact displacement sensor (CDS). According to the experimental results, the use of the GWB, having better measurement characteristics than the original light beam (OLB,) shows that its use is critical to the improved sensitivity of displacement measurements made by the CDS in a dual-channel homodyne interferometer. Finally, the achieved displacement sensitivity is around \(1.49^{\circ}/\upmu\)m in displacement, ranging from 0 to 40 \(\upmu\)m. According to the system stability of 0.007\({}^{\circ}\), the resolution of 4.7 nm is available.
# IEEE 802.11 ah: A Technology to Face the IoT Challenge
## 3 Comparative Analysis of IEEE 802.11 ah with Previous IEEE 802.11 Amendments
### Comparison of IEEE 802.11 Amendments Based on MAC Features  
IEEE 802.11 ah's physical layer is basically an adaptation of IEEE 802.11 ac to the sub-1 GHz band. The physical layer is a 10 times down-clocked version of IEEE 802.11 ac (symbol duration from 4 to 40 \(\upmu\)s), which keeps the same number of OFDM subcarriers. In consequence, the resulting channel bandwidth is ten times smaller than its IEEE 802.11 ac counterpart (i.e., 2, 4, 6, 8 and 16 MHz) and adds a special mode of 1 MHz. As mentioned before, IEEE 802.11 ah also defines a more robust MCS (BPSK 1/2 with repetition). The support of up to 4 \(\times\) 4 MIMO (including multi-user MIMO) can be used to enable spatial diversity and/or spatial multiplexing to increase the capacity of the links and to improve coverage.  
The key design feature for the IEEE 802.11 MAC is based on the channel access principle that enforces each station to sense the channel to be idle before initiating transmission, in order to avoid collisions. The MAC operation was designed based on Distributed Coordination Function (DCF) (explained below) protocol that utilizes the aforementioned principle. Despite the robust and adaptive nature of DCF in varying conditions, the initial MAC features were designed for best effort applications and thus did not require complex resource scheduling or management algorithms. However, the massive deployment of IEEE 802.11 networks has resulted in the need to include traffic differentiation and other sophisticated network management schemes. Furthermore, different versions of the IEEE 802.11 standard have been proposed with time, which include additional PHY and MAC features to accommodate the technological advances along with the ability to adapt to ever growing use cases.  
Table 2 highlights the key MAC features supported by each amendment. In particular, we highlight the critical MAC additions and changes being made for IEEE 802.11 ah, which will allow IEEE 802.11 standard to accommodate the IoT paradigm. The notable features compared in Table 2 are briefly introduced in the following paragraphs.
## 2 Methodology
### Numerical Simulation of HTB of Star Wheel Shift in WSSC
#### 2.2.3 Simulation Process  
The model of the water film was divided with structural mesh via ICEM CFD. The mesh in the thickness direction of water film is the key point of mesh division because water film thickness is found in extremely small quantities compared with radius direction. Taking the mesh quality together with the memory allocation of the computer into account, after multiple trials until the calculation results are essentially unchanged by the number of meshes, the total number of meshes for the research subjects in this paper is 1,142,448, which is appropriate. The mesh model is shown in Figure 7.  
The SIMPLE algorithm is selected as the solution method [26]. The solution considers that the fluid in the flow field inside an HTB is incompressible and the flow pattern is a three-dimensional steady flow. The boundary conditions are set as follows.  
1. Inlet boundary condition: The water pressure of the inlet is known, so the pressure inlet is adopted. The inletpressure is the water injection pressure of the WSSC.
2. Outlet boundary condition:There are two ends in the radial direction, both of which are outlets.The water pressure of the outlet was equal to that of the external environment.
3. Wall boundary condition:The wall in contact with the rotating ring adopted a moving wall and the speed is equal to the rotational speed of the star wheel shaft.The rest arethe stationary walls and all walls all adopt a no-slip boundary condition.
# Data-Driven Analysis of Outdoor-to-Indoor Propagation for 5G Mid-Band Operational Networks
## 2 Background, Related Work, and Contributions
### Contributions and Innovation
and multi-SSB network, using channel measurements executed in the 3.5 GHz band and with comprehensive correlation analysis of all channel parameters. The analysis of 5G propagation channels in Band n78 provided in this work allows for a better understanding 5G propagation characteristics in indoor scenarios, and also enables further refinement of channel models towards better performance evaluation and planning of 5G mid-band networks.
## 3 Accelerated Environmental Conditions and Test Methods
### Repeated Freeze/Thaw Cycles  
The possibility of fracture by repeated freezing and thawing cycles should also be considered. Moveable weirs, in particular, are subject to freezing and thawing cycles throughout winter. Tests were carried out in accordance with ASTM C 666 (American Society for Testing and Materials C 666, Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing, ASTM International, 2015, West Conshohocken, PA, USA) to evaluate the resistance of our hybrid panels to repeated freezing and thawing cycles. These tests involved 300 repeated cycles between \(-18\) and \(+4\)\({}^{\circ}\)C.