esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Design Concept and Methodologies
For rejection of DC and high order noise, a single-sideband (SSB) filter is inserted in the Fourier plane of the first 4_-f_ optics. It is monocolor system with a green (wavelength of 632 nm) laser as a light source. For the detail specifications of optical components used in the display system, please refer to [1]. In the second and later implementations of our system, the following are added as well as the enhanced functions. 1. The SLM module for color hologram generation is designed using three DMDs for each monocolor (R, G, and B) hologram, combining optics consisting of two prisms (one is trichroic and the other is TIR (total internal reflection) type), and three laser light sources with collimated beam output. In this way we preserve the image resolution of the monocolor display in color holographic display. Refer to [22] for some implementation details. 2. We have thus far a vertically narrow (4.7 mm) viewing stripe around and over the display. A vertical viewing angle of 20\({}^{\circ}\) is also required in order to permit the viewers' free position or posture (sitting on a chair, standing, or somewhere in between, as shown in Figure 2b) to view the hologram image, and this is achieved by adding vertical diffuser optics (a lenticular sheet, which is schematically shown in Figure 5) at the virtual SLM plane. Since diffusing optics degrades the spatial focusing capability of hologram somewhat, there is a tradeoff in this regard. 3. Vertical parallax is added inside this 20\({}^{\circ}\) of vertical viewing range (between 35\({}^{\circ}\) and 55\({}^{\circ}\) from the tabletop). For this, precise and fast pupil tracking of viewers with a dynamic update of the hologram images is implemented for a limited number of viewers. Pupil tracking module consists of multiple IR illuminator and cameras. Two cameras working as a stereo camera covers a viewer in 90\({}^{\circ}\) range, and four camera sets are used for 360\({}^{\circ}\) coverage, while supporting four viewers simultaneously. Figure 6 shows the working concept of the module and experimental  
Figure 5: 360-degree volumetric image floating on tabletop display. setup for 180\({}^{\circ}\) coverage with reconstructed image at four different vertical positions. Currently, update of pupil position is limited to 10 times per second, which is not sufficient for smooth update of hologram images following viewer's motion. 4. Capture of 3D information from moving real objects and the 360-degree perspective hologram CGH is implemented, and thus the signal chain from capture-CGH to display is demonstrated.
## 3 Experimental Results and Analysis
### Effect of Temperature on the Breakdown Voltage of Nanomodified Transformer Oil
From the graph, it is evident that the breakdown voltage of the nanofluid is consistently higher than that of the pure oil, with the most significant improvement observed at temperatures above 10 \({}^{\circ}\)C. Calculations using Equation (1) yielded the following results: When the temperature was above 10 \({}^{\circ}\)C, the addition of nanomaterials to the transformer oil led to an increase in the breakdown voltage by 18% to 21%. When the temperature was below \(-\)10 \({}^{\circ}\)C, the breakdown voltage could be enhanced by 13% to 15%. Within  
Figure 6: Experimental results of oil samples at high water contents. the temperature range of \(-10\)\({}^{\circ}\)C to \(0\)\({}^{\circ}\)C, the increase in breakdown voltage was relatively smaller, ranging from 8% to 9%, as determined by conducting multiple experiments and calculations. \[W=\frac{U_{NP}-U_{MO}}{U_{NP}}\times 100\% \tag{1}\]  
In the equation, \(W\) represents the percentage increase in the breakdown voltage of the nanofluid compared to that of the pure oil, \(U_{NP}\) represents the breakdown voltage of the nanofluid in kilovolts (kV), and \(U_{MO}\) represents the breakdown voltage of the pure oil in kilovolts (kV).
# Heat Loss Coefficient Estimation Applied to Existing Buildings through Machine Learning Models
## 1 Introduction
Among them, XGBoost is characterized for building regression trees, one-by-one, so that the subsequent models are trained taking into account the residuals of the previous ones [16]. This algorithm has been used in numerous fields such as biology [17; 18], econometrics [19], the environment [20; 21] or, as in this case, the energy performance of buildings [22; 23]. SVR models emerged as a predictive alternative due to the use of a distinctive loss function [24; 25], on the one hand, and the dual formulation of the problem [26], on the other. This algorithm focuses on minimising an upper bound of the generalization error instead of minimising the prediction error in the training sample (_empirical risk minimization_) [24]. The usefulness of this algorithm is demonstrated by its expansion into scientific fields such as econometrics [26], health [27; 28], electrical efficiency in cities [29], as well as energy consumption in buildings [25; 30]. Lastly, MLP neural networks have stood out in past years for their great capacity to model non-linear relationships between certain inputs and outputs, as well as for their massive interconnectivity [31; 32; 33]. Furthermore, this type of Artificial Neural Network (ANN) has been applied to different areas of study such as chemistry [34], the environment [35; 36], sensors [37] or energy analysis of buildings [38; 39; 40]. The aim of this paper is to estimate the HLC of an existing building through the prediction of building thermal demands using a methodology based on ML models. Specifically, three different methods are applied to a public library in the northwest of Spain and compared: XGBoost, SVR and MLP neural network. The dataset consists of hourly observations of two climate variables (outdoor temperatures and solar radiation) and two variables related to the thermal behaviour of the building (heating demand and indoor temperatures). In addition, to improve model training, three temporal variables (hour of the year, day of the week and hour of the day) are taken into account as model inputs. A comparison between the errors obtained by the different machine learning models is carried out on three different validation samples. Moreover, the accuracy of each of the models is quantified with CV(RMSE) and Normalized Mean Biased Error (NMBE), both recommended by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), and their usefulness was demonstrated in [41; 42]. The novelty of this work lies in the application of machine learning models to estimate the HLC of a building through heating demand predictions. In this context, this paper contributes with a methodology that reduces the exigency of building monitoring, and heating demands will be accurately predicted. Additionally, this methodology does not depend on physical simulations, which require huge amounts of input data and specific knowledge and which have uncertainty in the evaluation of energy renovation or the energy certification of buildings.
## 3 Results and Discussion
### Biochar Production Process
Above 500 \({}^{\circ}\)C there is a more intense oxidation of chemical functional groups and the aromaticity of surface biochar increases. The temperatures at which pyrolysis occurs for the predominant components of the feedstock can thereby determine the properties of the feedstock at the end of the process. Thus a lower content of lignin in bamboo may be an explanation for the lower overall temperatures recorded in our case for the bamboo biochars (Figure 1). Higher contents of cations in bamboo feedstocks may as well lead to lower pyrolysis temperatures, as discussed in previous works [36; 37; 38]. Table 1 provides characterization data of feedstocks from several bamboo and coniferous species, reported by other authors. While conifers produce wood, bamboos are giant grasses that produce a lignocellulosic material significantly different in its chemistry and structure. Nevertheless, Table 1 shows notable similarities in contents of cellulose and hemicellulose, as well as in heat values. The lignin contents in the conifers seem only slightly higher. The ash contents reported for the bamboo feedstocks, however, are around one order of magnitude higher. The influence of the presence of alkali cations on the temperatures and mechanisms of pyrolysis of lignocellulosic materials has been investigated since over three decades by now [36]. The presence of salts of alkali cations has been shown to considerably lower pyrolysis temperatures [37; 38], and change the yields of char and of the different volatiles as well. As it depends on the drying method and time, as well as on the storage conditions, the comparison of moisture data is not sought. Table 2 summarizes the temperatures in the TLUD stove during each 60 min of total residence time, including firing and charring time. The lowest average temperature registered was for BB1. Generally, pinewood temperatures were higher, with averages between 554 and 654 \({}^{\circ}\)C, while bamboo produced average temperatures between 258 and 534 \({}^{\circ}\)C, and BB1 shows the shortest holding time near 500 \({}^{\circ}\)C.
## 2 Material Constitutive Model and Interface Cohesive Zone Model
### Interface Cohesive Zone Constitutive Model  
The cohesive zone model, which is widely used in interface damage and cracking of composite materials analysis, can accurately estimate the crack initiation and propagation process on the cracking path and can better describe the nonlinear interlayer damage behaviour of concrete [29]. The cohesive zone theory is characterised by the interface constitutive law, which is the relationship between interface adhesion and interface displacement and cracking. The standard cohesive zone constitutive models are bilinear, exponential, trapezoidal and plastic cohesive zone models. For the problem of interlayer bond damage of track structures, the bilinear cohesive zone model is adopted in the literature [30], as shown in Figure 1.  
Figure 1: Bilinear cohesive zone model.  
The model assumes that the interface stiffness \(K\)i (including normal and tangential stiffness) decreases linearly dependent on the interface displacement after the damage increases. The formula of damage variable \(D\) is given by the following Equation (24).  
\[D=\left\{\begin{array}{ll}0,&0\leq\delta^{\text{max}}\leq\delta^{0}\\ \frac{\delta^{c}\left(\delta^{\text{max}}-\delta^{0}\right)}{\delta^{\text{max} }\left(\delta^{c}-\delta^{0}\right)},&\delta^{0}<\delta^{\text{max}}<\delta^{c }\\ 1,&\delta^{\text{max}}>\delta^{c}\end{array}\right. \tag{24}\]  
where \(\delta^{0}\) is the displacement at the time of interlayer interface damage initiation, \(\delta^{c}\) is the displacement at the time of interlayer interface crack initiation and \(\delta^{\text{max}}\) is the maximum reached displacement during the loading process.  
The quadratic nominal stress damage criterion is used to identify the initiation of interface damage. Damage initiation corresponds to the moment at which the sum of the squares of nominal stress ratios in all directions is equal to 1:  
\[\left\{\frac{\left\langle t_{n}\right\rangle}{t_{n}^{0}}\right\}^{2}+\left\{ \frac{t_{s}}{t_{s}^{0}}\right\}^{2}+\left\{\frac{t_{t}}{t_{t}^{0}}\right\}^{2}=1 \tag{25}\]  
where \({t_{n}}^{0}\) is the normal strength, and \({t_{s}}^{0}\) and \({t_{t}}^{0}\) denote the strength in the two tangential directions.
# Predicting Shot Accuracy in Badminton Using Quiet Eye Metrics and Neural Networks
## 3 Research Gaps Addressed by This Study
### Real-Time Analysis and Feedback  
Most QE studies rely on post-hoc data analysis, leaving the real-time potential of QE for immediate feedback underutilized. Recent advancements in mobile eye-tracking technology and motion capture systems [20; 21] present opportunities to provide near real-time feedback during training or competitive play. Our study aims to develop methods for the real-time analysis and prediction of shot accuracy using QE and biomechanical metrics, which could revolutionize performance tracking in badminton.
# Discrimination Accuracy of Sequential Versus Simultaneous Vibrotactile Stimulation on the Forearm
### Can Braille Be Conveyed with Vibrotactile Stimulation?  
Traditional Braille reading involves moving one's hand from left to right across lines of raised dots, primarily utilizing the fingertips. However, vibrotactile displays offer a potentially hands-free Braille reading alternative. Notably, previous studies suggest that blind individuals often possess superior tactile spatial acuity compared to their sighted counterparts, potentially enhancing their capacity to accurately interpret Braille patterns through vibrotactile stimulation [7; 8; 13; 14; 15; 16].  
Vibrotactile displays are emerging as a promising substitute for conventional Braille systems for those with visual impairments. Their appeal lies in their portability, versatility, and capability to represent a vast array of characters and symbols. Notably, designs like the sleeve-based variant that we tested here stimulate passive body areas, keeping hands free for other tasks. The efficacy of these displays is often determined by various factors, such as resolution, thresholds, frequency, amplitude, and stimulus duration [17; 18; 19; 20; 21; 22; 23]. These displays can employ varied vibrotactile stimulation patterns to convey diverse information, from images to navigation instructions [24; 25; 26]. The intensity and frequency of the vibrotactile stimuli are adjustable, allowing for a large number of possible stimulation combinations.  
Our research group has delved deeply into vibrotactile stimulation properties, especially in sensory augmentation devices [7; 8; 27; 28; 29; 30; 31; 32; 33; 34]. One notable system that we have developed is the \"The Sound of Vision\" sensory substitution platform for the visually impaired. The system uses time-of-flight (ToF) and stereo cameras to survey the surroundings, translating the data into tactile and auditory signals. A unique tactile belt communicates the direction of and distance to potential obstacles using vibrations. The system has yielded promising results in user tests [8].
## 3 Results and Discussion  
### Spectroscopic Analysis on Charge-Transfer Complexes of Bar  
The main characterized analyses of the four synthesized Bar charge-transfer complexes (Figure 2) can be explained in Table 1.  
Figure 2: Suggested structures of barbital (Bar) charge transfer complexes. The molar ratios between Bar donor and the four acceptors were deduced according to the spectrophotometric titration at room temperature [45]. This titration was performed at 300, 360, 320, and 520 nm for (Bar-DBQ), (Bar-TCNQ), (Bar-CHL), and (Bar-CLA), respectively, in methanol solvent at variable receptor concentrations, ranging from 4 \(\times\) 10\({}^{-4}\) to 0.25 \(\times\) 10\({}^{-4}\) M, and at a fixed Bar concentration of 1.0 \(\times\) 10\({}^{-4}\) M, resulting in a molar ratio of the product (Bar: acceptor) spanning the range from 4:1 to 1:4. It can be seen that the largest interaction occurs between Bar and DBQ, TCNQ, CHL, and CLA in a 1:1 ratio. In addition, weak bands at 2705, 2656, 2600, and 2565 that result from hydrogen bonding in the byproduct (N-H\(\cdots\)O) were seen in the infrared spectra of (Bar-CLA). These findings suggest that Bar and the CLA acceptor have formed an intermolecular H-bond [46,47]. The CHL receptor's infrared spectrum characterized the main bands at (903 and 709), 1263, 1487, 1567, and 1685 cm\({}^{-1}\) for \(\
u\)(C-Cl), \(\
u\)(C-O), \(\
u\)(C=C), \(\
u\)\({}_{8}\)(C=O), and \(\
u\)\({}_{88}\)(C=O), respectively (Figure S1). The CHL, TCNQ, and DBQ receptors have an electron-withdrawing action that makes it simpler for them to take n electrons from the Bar molecule. The main bands of \(\
u\)(N\(-\)H) vibrations at 3234 and 3103 cm\({}^{-1}\) for (Bar-CHL), were found to be shifted to 3242 and 3160 cm\({}^{-1}\), 3209 and 3171 cm\({}^{-1}\) for (Bar-TCNQ), and 3256 and 3168 cm\({}^{-1}\) for (Bar-DBQ), due to complexity (Figure S1).
# A Taxonomy for Security Flaws in Event-Based Systems
## 3 Taxonomy
### Taxonomy Construction Methodology
Prior research has defined and introduced a particular concurrency problem that only exists in EBSs, referred to as event anomalies [81; 127; 128]. [PERSON]'s taxonomy does define \"Concurrency\" flaws, but only includes time-of-check to time-of-use (TOCTTOU) errors; therefore, we expanded the scope of their characteristics and changed the name of the category to \"Inadequate Concurrency\" to present a more precise definition. The existing approaches indicated that the components in an EBS may communicate via covert (i.e., non-system-standard) communication channels [119; 47; 100]. Although some types of \"Covert Channels\" flaws were defined in [PERSON]'s taxonomy, we extended them to include newly identified covert channels such as the battery and vibrator in mobile devices. Authentication issues were also identified in EBSs, in the form of permission grant and authentication in a multi-domain EBS--a particular type of EBS comprising multiple event-brokers from different domains [65; 80; 86; 90; 108; 118; 120; 135]. We extended the \"Inadequ Authentication\" category in [PERSON]'s taxonomy to include those authentication-related flaws. From Android apps, new types of resource leaks such as resource leaks via wifi and SQLite database were introduced [40; 45; 88; 104; 106; 114; 115; 126; 129; 132], which can be added to \"Resource Leak\" in [PERSON]'s taxonomy. We changed the name of the category \"Inadequate Resource Management\" to define the scope more broadly. We also found that the flaws that existing approaches try to resolve fall under \"Logic/Time Bomb\" in [PERSON]'s taxonomy [56; 103; 115]. The existing EBS research introduced the knowledge of flaws where multiple components collude to exploit the system [45; 47; 61; 88; 100; 104; 106; 109; 117; 131]. Moreover, the majority of security attacks in EBS are basically caused by its extensible event communication channels [22; 24; 39; 40; 41; 45; 47; 52; 60; 68; 70; 71; 77; 94; 97; 99; 130; 135]. As [PERSON]'s taxonomy does not include them, we extended the definitions of \"Conspirator\" and \"Open Event Channels,\" respectively. We also added \"Unsafe Events\" and \"Unsafe Event Interface\" for including cases where those open event channels are unintentionally introduced to the system [22; 24; 39; 41; 68; 69; 70; 75; 77; 79; 84; 85; 87; 95; 102; 130; 123; 131]. Note that, to guarantee the completeness of taxonomy, all the flaws extracted from the existing publications were incorporated in the new taxonomy. However, drawing from the flaws in the [PERSON]'s taxonomy, we excluded those that were not introduced in the existing literatures under review to build a taxonomy specialized for EBSs.
# An Overview of Cube-Satellite Propulsion Technologies and Trends
## 12 Conclusions
PPTs like electrospray systems require power of an order of magnitude lower than Hall and RF ion thrusters because of the relatively simpler design that involves the generation of an arc to ablate the propellant. They also have the lowest average thrust-to-power ratio amongst all surveyed electric engines. Solar sails, on the other hand possess infinite specific impulse, but their operation is dependent on the distance from sun, and they generate small magnitude of thrust resulting in a long time to gain appreciable momentum change. Micro-propulsion systems belonging to cold gas, resistojets, electrospray and vacuum arc thrusters have flown on CubeSat missions. An ion thruster is also scheduled to be launched on a CubeSat in the near future. Some of the remaining technologies surveyed in the paper belonging to cold gas, liquid, solid rocket, ion, Hall, electrospray and pulsed plasma thrusters have been used on larger spacecraft for secondary propulsion needs. These technologies have the potential to be used on future CubeSat missions. **Author Contributions:** [PERSON] performed a survey of micro-propulsion technologies under the guidance of [PERSON]; [PERSON] is the lead author of the paper; [PERSON] is the co-author. **Conflicts of Interest:** The authors declare no conflict of interest.
## 3 Proposed Scheme
### Trustworthiness and QoS-Based Path Discovery and Selection Procedure
In the case of the C, D, and E data packets, the paths satisfying the requirements were 1, 2, and 3, which were randomly selected and used after being assigned, as shown in Figure 2. As shown in Paths 4 and 5, if a malicious node performed a gray hole or DoS attack, it was detected, and the path was excluded. Each sensor node could transmit data along a path that guaranteed trustworthiness and QoS because it detected and excluded malicious nodes beforehand.
## 3 Long-Term Durability of Sensor Coupling and Mounting and of the Measurement Equipment
### Long-Term Sensor Coupling
#### 3.1.1 Surfaces to Which AE and GUW Transducers Are Coupled
The most important aspect for the selection of the mounting device or method is, however, stated as follows: _\"Detection of surface waves may be suppressed if the sensor is enclosed by a welded-on fixture or located at the bottom of a threaded hole. The mounting fixture should always be designed so that it does not block out a significant amount of acoustic energy from any direction of interest\"_. A suitably designed sensor mount device, on the other hand, may also prevent a sensor that has lost contact with the surface of the test object from falling off or, on the other hand, can be damaged by impact from falling objects, e.g., tools, hail, bird strikes, etc., especially in field testing. Examples of special contact conditions sometimes requiring specific couplant media and/or sensor mounts are AE sensors coupled to biological tissue [76]; to electric power devices, mainly applied for detection of partial electric breakdown [77], in corrosive environments [78], in nuclear or ion radiation areas [79]; to snow or ice [80; 81]; and possibly to certain art and archaeological objects where couplants and sensors may not leave any mark and surface preparation of the test object is not possible. Some of the conditions noted here may not only require special couplant materials but may also affect the short-term or long-term performance of the transducers themselves.