esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Theoretical Background
### Research Aim and Questions  
Little research has been done on students' learning of the congruence concept [17], which is especially true for students who have difficulties in mathematics. The topic of congruent triangles is considered difficult for students [16]. Since ethnomathematics makes school mathematics more relevant and meaningful for students [21], it is a possible candidate for overcoming students' difficulties in mathematics. The current research aims to study the effect of using Islamic ornamentation to teach congruent triangles to students who find mathematics difficult by answering the following questions:1. What characterizes students' definitions of congruence and congruent triangles?
2. What characterizes students' learning processes when they are taught about congruent triangles based on Islamic ornamentation?
3. To what extent does ethnomathematical learning of congruent triangles based on Islamic ornamentation affect students' knowledge of congruent triangles?
## 3 Methodological Procedure
### Evaluation Process  
The evaluation process aims to compare and select the most suitable regression model for estimating the HFF slope in the data set \(\mathcal{D}_{\text{set}}\). In order to accomplish this, we adopt the following approach (see Figure 1):  
1. We implement a hold-out cross-validation, which involves randomly dividing the entire data set, \(\mathcal{D}_{\text{set}}\), into 70% for training purposes, while the remaining 30% is designated as the validation set. To account for the random nature of the process, this procedure is repeated a total of 30 times. It is important to note at this point that, in each iteration, the training and testing data sets are mutually exclusive.
2. The training set is used to adjust the weights of each regression model, while the test set is utilized to evaluate the performance of the model. Note that all ML regression models are trained and evaluated using mutually exclusive data sets.
3. To evaluate the effectiveness of various machine learning regression models, we have introduced three performance metrics (Section 3.3): the coefficient of determination (\(r^{2}\)), the root mean squared error (RMSE) and the mean absolute percentage error (MAPE). These metrics allow us to assess how accurately each regression model produces estimates. Based on the scores obtained, we can determine the best performance algorithm to estimate the slope of the HFF.
## 2 Technology and Design
### Level of Detail Management  
A software approach for creating \"lighter\" datasets to render or to stream over a network is called _level of detail management_ (often referred to as LOD) in computer graphics literature. First attributed to [PERSON] (1976) [40], LOD is a relatively old concept in computer years and is very commonly employed today. Most LOD approaches are concerned with partially simplifying the geometry of _three-dimensional_ models (e.g., city or terrain models) where appropriate [41, 42, 43]. However, conceptually it is possible to draw parallels to other domains dealing with _two-dimensional_ graph simplifications such as _progressive loading_ (transmitting data incrementally) in streaming media, _mipmapping_ in texture management or some of the cartographic _generalization_ processes in map making. Figure 2 (below) shows a simplified model of a two-dimensional space partitioning for managing level of detail using a specific approach called _foveation_ based on perceptual factors [44].  
Foveation removes perceptually irrelevant information relying on the knowledge from human vision, that is, we see dramatically more detail in the center of our vision than in the periphery [45, 46]. Many LOD approaches use a similar (though not identical) hierarchical organization with different constraints in mind. The inspiration of LOD management may come from perceptual considerations (e.g., distance to the viewer, size, eccentricity, velocity, depth of field) as well as practical constraints (e.g., priority, different culling techniques; visibility culling, occlusion culling, view frustum culling) [42, 47, 48].  
The LOD concept as handled in computer graphics literature has also been used in geographic information visualization when working with terrain (e.g., mesh simplification) and city models [50, 51]. In fact, for the city models, it has become a standard, namely, CityGML [49, 52]. One can plan, model or deliver/order data in five levels of detail according to the CityGML standard, referred to as LOD 0, LOD 1, LOD 2, LOD 3, and LOD 4 (Table 2, Figure 3). LOD 0 typically is a regional model and expresses e.g., 2.5D digital terrain model or a \"box\" for a building without roof. LOD 1 is a city/site model that would have blocks of objects, i.e. buildings with roof structures. LOD 2 is also a city model, but _with textures_. LOD 3 adds further details to architecture of individual objects, and, LOD 4 is used for \"walkable\" architectural models including the building interiors [53].  
_LOD management_ usually involves determining a parameter as to where and when to switch the LOD in the visualization process. When implemented well, LOD management essentially provides a much needed _compression_ that works like an _adaptive_ visualization. Ideally, a successful LOD management approach will also adapt to human perception, therefore the compression may be _perceptually lossless_. In many of today's applications, LOD switches help a great deal with the lag times and are relatively successfully utilized in progressive loading models, however the adaptation of the visualization is often not seamless.
## 1 Introduction
Electrokinetic measurements provide a mean for studying such different phenomena as the adsorption of ionic species on inorganic substrates or of proteins on surfaces of biological interest, as well as the extent of modification of the substrate surface and its time-dependent evolution [20]. Furthermore, the zeta potential can be an extremely useful parameter in the description of granular or fibrous materials and of porous ones such as, e.g., semipermeable membranes [21] and natural stones [22], especially in connection with their behaviour in aqueous media as a function of pH [23; 24]. Nevertheless, there is still a nearly complete lack of studies concerning the characterization of natural stone surfaces [25] and the effect on the surface zeta potential resulting from treatment applications [26]. The aim of the present study is to explore the potential of electrokinetic analysis as a tool to better understand the changes occurring at the surface of natural stones after the application of protective coatings. For this purpose, the results of streaming current measurements are compared with the observed changes in the stone-water interaction as assessed by two commonly employed parameters for the evaluation of protective effectiveness, namely surface wettability and water absorption by capillarity [9]. It is worth stressing that a multiplicity of factors contributes to the effectiveness of a protective coating, particularly if nanocomposite is in its formulation; among them, the porosity, pore size distribution and roughness of the substrate; the intrinsic hydrophobicity of the coating material and its ability to produce a uniform and continuous (but not occluding) layer sheeting both the outer stone surface and the outermost pore walls. The present study was focused on devising an electrokinetic-based parameter suited for the semi-quantitative estimation of the degree of surface modification, allowing a prediction of the overall behaviour of a given coating-stone system. For this purpose, three lithotypes (natural stones selected among those used as construction materials in historic buildings) with different microstructural and mineralogical properties and two different coating formulations were considered. The formulations, consisting of liquid dispersions of different organosilica matrix precursors combined with titania nanoparticles, were developed in the framework of the EU-funded NanoCatheral project, dealing with the setup and testing of innovative nanocomposite materials for the conservation of European architectural heritage. Their protective effectiveness was evaluated by static contact angle and water absorption measurements, performed on the lithotypes before and after the application of the coating formulations. In addition, electrokinetic characterization of untreated and treated stones and of the coatings obtained by casting onto a non-porous reference substrate was performed. The existence of well-defined correlations between the changes induced by the coatings on the electrokinetic properties and the reduction of surface wettability and of capillary water absorption in the treated stones was investigated.
## 4 Methodology
### Search Criteria Formulation  
The search criteria used were:  
* C1: (\"Edge computing\" OR \"IoT\" OR \"wearables\" OR \"wearable sensors\") AND (\"chronic\" OR \"infectious\") AND (\"disease\");
* C2: (\"AI\" OR \"edge intelligence\" OR \"machine learning\" OR \"deep learning\" OR \"federated learning\") AND (\"chronic\" OR \"infectious\") AND (\"disease\" OR \"health prediction\");
* C3: (\"predictive models\") AND (\"chronic\" OR \"infectious\") AND (\"disease\");
* C4: \"Privacy\" AND \"health prediction\".  
The purpose of this review paper is to answer the following research questions.  
* **RQ-1**: What are the myriad applications of Edge AI in early health prediction? This research question seeks to uncover research efforts and breakthroughs in the use of Edge AI for the early detection of chronic and infectious diseases.  
* **RQ-2**: What machine learning and deep learning models are used in early health prediction?
* **RQ-3**: What techniques and methods are used to preserve privacy in early health prediction and detection of the onset of chronic and infectious diseases?
* **RQ-4**: What are the potential open research issues and future directions of Edge AI for early health prediction and detection of chronic and infectious diseases? This question seeks to define the unanswered inquiries and unexplored paths that hold the key to unlocking the full potential of Edge AI in early health prediction. By unraveling the challenges that can hinder their widespread adoption and delving into research directions, this query drives researchers to understand the current landscape of Edge AI and early disease detection, unraveling novel insights and paving the way for transformative advancements in this domain.
# Numerical Simulation of Co-Barrier Efficiency of Air Curtains in Mine Refuge Chambers
## 3 Simulation Results
### Effects of Installation Position and Jet Velocity
#### 3.1.3 Installed the Air Curtain on the Top Side  
Figure 12 illustrates that installed on the top side of the refuge door frame causes the barrier efficiency of the air curtain first increases and then decrease as jet velocity increases. The air curtain is most effective when the jet velocity is 22 m/s, and the CO concentration in the transition room is 2740 ppm at 300 s.  
Compared with the air curtain installed in other positions, the air curtain installed at the top side provides the best barrier efficiency because the air flows into the outside environment from the lower side of the neutral surface while the high concentration of CO gases in the outside environment flows into the transition room from the upper side of the neutral surface, driven by heated pressure. The air curtain erected on the top side of the refuge chamber has the best blocking effect because it can effectively stop CO gases from entering the transition chamber on the top side of the neutral plane. The ideal velocity of the air curtain is 22 m/s. The number of air curtain inlets installed on the top side is the lowest compared to those installed in other locations. The air curtain must increase the jet velocity to have more kinetic energy in order to resist the effect of external heat pressure and create the best barrier effect.  
It is evident from the data above that the air curtain installation position and jet velocity greatly affect the barrier CO efficiency. Various air curtains with different jet velocities have different barrier effectivity at the same installation point. For the same jet velocity, the air curtain barrier efficacy varies depending on the installation position. The efficiency of the barrier cannot always be increased by increasing the air curtain jet velocity when the air curtain position is known. In all of the above conditions, the air curtain with 22 m/s jet velocities erected on the top side offers the best barrier effect.
# Modular Combined DC-DC Autotransformer for Offshore Wind Power Integration with DC Collection
## 2 MCAT Topology and Its Operation Principles  
### Topological Structure  
As depicted in Figure 2, two DC grids with different DC voltage levels are connected by the proposed MCAT. MMCs highlighted by blue and red colors are defined as a low voltage module (LVM) and a high voltage module (HVM), respectively. The LVM is composed of \(M\) identical MMCs including \(\text{MMC}_{\text{L},1}\) to \(\text{MMC}_{\text{L},M}\). Likewise, the HVM is composed of \(2N\) identical MMCs including \(\text{MMC}_{\text{H},1}\) to \(\text{MMC}_{\text{H},2N}\). It is obvious that \(M\) and \(N\) are driven by voltage levels of DC grids on two sides of the MCAT.  
The function of converter transformers is mainly focused on three aspects [17]:  
1. Coordinating the AC system voltage and the AC output voltage of MMC.
2. Galvanic separation between the AC system and the MMC to eliminate the DC offset voltage.
3. Acting as the inductor to smooth the current and suppress the fault current. According to the operation principle of the MCAT, the item (2) is an indispensable function. This paper uses a capacitor (namely DC-isolation capacitor) to withstand the DC offset voltage, so that the converter transformer is eliminated. Since the introduced DC-isolation capacitor would produce reactive power, an inductor (namely compensation inductor) is installed to compensate the reactive power and improve the MCAT operation efficiency. In order to reduce the footprint of DC-isolation capacitors and compensation inductors, the medium frequency (100 Hz-400 Hz) is applied at the MCAT AC side. AC circuit breakers are also equipped for isolating the AC fault.  
Figure 2: Schematic diagram of the MCAT topology.
# Wound Dressing Materials: Bridging Material Science and Clinical Practice
## 4 Antimicrobial Dressings
### Medical-Grade (Manuka) Honey  
Honey has long been recognized for its healing properties, and modern research supports its use in antimicrobial wound dressings such as MediHoney(r), Activvon Tulle(r), Algivon(r), and Actilite(r)[92; 93]. Honey inhibits bacterial growth through its osmotic effect, low pH, and the presence of antibacterial compounds like methylglyoxal [94]. Manuka honey (MH), in particular, maintains its antibacterial activity even in the presence of biological fluids due to its unique non-peroxide component [92; 93]. Beyond its antimicrobial action, honey supports wound healing by providing topical nutrition. In patients with venous ulcers, MH dressings have been shown to reduce wound size, pain, and malodor significantly [95]. MediHoney(r) enhances debridement by drawing fluid from deeper tissue layers through its osmotic effects, aiding in the removal of dead tissue. Additionally, honey's anti-inflammatory properties, along with its ability to promote angiogenesis, granulation tissue formation, wound contraction, and epithelialization, further accelerate the healing process [92; 93].
# Auditory Device Voice Activity Detection Based on Statistical Likelihood-Ratio Order Statistics
## 1 Introduction
The DNN-based VAD method has significantly improved the performance of such conventional approaches, even though it requires a more complex neural network architecture for greater accuracy [16; 17; 18; 19]. Despite its strengths, however, it suffers from significantly high computational costs. Thus, it is currently difficult to use DNN-based approaches for speech-processing algorithms (e.g., VAD) in auditory devices (e.g., hearing aids) that require low computational complexity in real-world applications. The purpose of this study is to develop a VAD algorithm to be implemented in auditory devices in which filter bank algorithms must satisfy specific requirements for signal quality, computational complexity, and signal delay [20; 21; 22; 23; 24; 25; 26]. Auditory devices should have uniformly spaced narrow frequency bands and at least 60 dB stopband attenuation, preferably higher [20; 21; 22]. Moreover, the signal-processing delay should be below 10 ms to avoid the unfavorable effect to the subjective listening experience [23; 24], which requires low computational cost due to the restricted battery capacity in real-world portable devices [22; 25; 26]. Accordingly, a discrete Fourier transform (DFT)-based uniform polyphase auditory filter bank is typically used. It is efficient, expandable into nonuniform filter banks, has low latency, and has perfect reconstruction characteristics [20; 21; 26]. Moreover, it has the advantage of being implemented as an overlap-and-add (OLA) with a short-term Fourier transform (STFT) [11; 22]. Consequently, this study intends to employ STFT-based VAD algorithms on a uniform polyphase DFT filter bank for auditory hearing aids. The remainder of this paper is organized as follows. Section 2 proposes a uniform polyphase DFT filter bank for implementing the proposed auditory device VAD. Section 3 briefly reviews a conventional statistical LRT-based VAD approach. Section 4 proposes how to use LR order statistics for VAD. Section 5 evaluates the performance of the proposed method. Finally, Section 6 concludes this paper.
# Spectral Shaping of a Superluminescent Diode for Terahertz Cross-Correlation Spectroscopy
## 2 Experimental Setup  
### THz-CCS System  
In this section, we explain the system configuration which was used for the indirect optical terahertz pulse shaping. The experimental setup is depicted in Figure 1. The system is split into four parts: light source system, terahertz system, electronic system for data acquisition, and the power supply unit (PSU). This section will focus on the light source system part, which is highlighted in red. It contains all the system components for manipulating and shaping of the terahertz spectrum. The terahertz and electronic system are like a conventional THz-CCS system. The light source is a commercially available SLD (SLD1550P-A40, Thorlabs, Maisons-Laffitte, France) which was also used by [PERSON] et al. [12]. The injection current for the experiments was I\({}_{\text{diode}}\) = 600 mA. The typical optical output power at a current of 600 mA is 50 mW. For the optical shaping, a programmable optical filter (POF, Finisar Wave Shaper 1000A) and for amplification an erbium-doped fiber amplifier (EDFA, EDFA100P, Thorlabs, Maisons-Laffitte, France) were used. The POF has an operating wavelength range from 1526 nm to 1568.7 nm and it can attenuate frequency components by up to 35 dB with a step size of 0.01 dB. The EDFA has a maximum output power of 23 dBm and an operating wavelength range from 1530 nm to 1565 nm. In front of the terahertz system part, the resulting optical spectrum is analyzed by splitting the optical power in 99% and 1% and sending 1% to an optical spectrum analyzer (OSA MS9740A, Anritsu, Kanagawa, Japan). After that, the signal gets split by a 50:50 beam splitter to the emitter on the one side and to the receiver on the other side. The receiver signal gets delayed in the free space part of a fiber-coupled mechanical delay line (OZ ODL-650-ML), which has a travel range of 50 mm (=330 ps), in a continuous scanning mode. The emitter is a InGaAs p-i-n photodiode, and the receiver is a photomixer for continuous wave excitation [13]. Both antennas are designed for an excitation wavelength of 1550 nm. In the terahertz path, four TPX-lenses (TPX35, Menlo, Mountain View, CA, USA) are used to guide the terahertz radiation from the emitter to the receiver. For alignment of the path, a terahertz frequency-domain (THz-FDS) system (Terascan 1550, Toptica, Munich, Germany) was used. This enables a qualitative comparison of system performance in different operating modes. The data acquisition (DAQ) used for the experiments is based on a Zurich Instruments MLFI 5 MHz lock-in amplifier. The integration time was set to 1 us and the bias for the emitter to 1.4 V peak-to-peak amplitude with \(-\)0.2 V offset at a modulation frequency of 11.25 kHz which are the recommended settings from the manufacturer.
## 3 Results and Discussion
### Evaluation of the Effective Action Distance of V-Shaped Hole Cleaning Device  
The effective action distance under the rotation of the V-shaped hole cleaning device in the experiment is shown in Figure 14. It can be seen that after a certain distance behind the hole cleaning device, there are cuttings bed accumulation in the annulus. The cuttings can be suspended in the annulus within a distance behind the device due to the spiral flow induced by the hole cleaning device. The spiral flow continues to decay, making it difficult for the particles to maintain the suspended state and to begin to settle and form a cuttings bed along the flow direction. Finally, the cuttings bed height increases to a stable state.  
Figure 12: Vorticity and streamline distribution of the hole cleaning device under different helix angles.  
Figure 13: Annular cuttings concentration contour at different helix angle conditions.  
As shown in Figure 15, the V-shaped hole cleaning device with helix angle \(\alpha\) = 20\({}^{\circ}\) was selected and placed on the drill pipe of the flow loop to conduct hole cleaning experimental research and to compare it with the numerical simulation results. The effective action distance of the V-shaped blade increases as the rotational speed increases. According to the simulation results, when the speed reaches the maximum (200 rpm), the effective action distance can reach 1.8 m, slightly higher than the experimental results. When the rotating speed is between 160 rpm and 200 rpm, the increment of the effective action distance is more significant than when the rotational speed is low. The comparison between our numerical results and experimental data shows that the Eulerian-Eulerian TFM model is suitable for the numerical simulation of solid-liquid two-phase flow in the annulus and can obtain high prediction accuracy.