esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Conclusions  
At present, the design of reinforced rib layouts and dimensions for parabolic cylindrical reflector antennas is an area worthy of attention. Many existing designs relied on the engineering experience of designers, lacking a theoretical foundation. Moreover, there is a scarcity of studies investigating the impact of reinforced rib parameters on the RMS of the reflector surface. In this study, focusing on the parabolic cylindrical reflector antenna of MICAP, we proposed a design approach that combines topology optimization and parametric analysis. Based on the optimization results, a new layout for the reinforced ribs was designed and a parametric analysis was conducted on the new layout of the reinforced ribs. By obtaining suitable height and thickness values, we also elucidated the impact patterns of these two parameters on the RMS of the antenna's reflector surface under the new layout. Using simulated thermal excitations from orbital external heat flux and antenna temperature fields, finite element thermal distortion analyses were performed on the different models, comparing the RMS of the antenna's reflector surface before and after optimization. In comparison to the original reinforced rib design, the optimized RMS was reduced by 7.7%, without additional volume. When compared to the reflector surface without reinforced ribs, the optimization resulted in a reduction of 17.9% in RMS.  
However, the influence of height and thickness on the RMS of the reflector surface antenna was limited to a specific layout. Subsequent efforts should focus on generalizing these patterns, to enhance their broader significance.  
Conceptualization, P.K., W.F. and H.L.; methodology, P.K. and W.F.; software, P.K. and M.L.; validation, P.K. and D.W.; formal analysis, P.K.; investigation, P.K. and M.L.; resources, H.L; data curation, W.F. and H.L.; writing--original draft preparation, P.K.; writing--review and editing, W.F. and H.L.; visualization, P.K.; supervision, W.F. and H.L.; project administration, H.L. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to confidentiality reasons as the project is not completed. The project is expected to be completed by December 2024.  
The authors declare no conflict of interest.
## 6 Simulation Experiments and Performance Analysis
### Communication Performance Analysis  
First, an analysis of the communication performance of UFMC chirp is conducted. The primary factor affecting the performance of UFMC is the subdivision of its sub-bands. To validate the performance results under different sub-band partitioning scenarios, the simulation parameters for UFMC chirp are provided in Table 1.  
To highlight the advantages of UFMC chirp, a comparative analysis was conducted among four different modulation schemes: OFDM, FBMC chirp, parameter modulation, and UFMC chirp, all executed under identical experimental settings. The experimental results are presented in Figure 10.  
In Figure 10, the blue dashed line represents the bit error rate (BER) results of OFDM signals in Rayleigh channel conditions, the yellow plus sign line represents the results of FBMC chirp signals, and the red circle line represents the results of parameter modulation. The purple hexagon, green pentagram, and light blue rhombus lines represent the results of UFMC chirp under different sub-band partitioning. Analysis of the figure suggests that the communication performances of FBMC chirp, parameter modulation, and UFMC chirp surpass that of OFDM signals. This superiority can be attributed to the filter structures utilized in joint waveforms FBMC and UFMC, resulting in reduced out-of-band leakage and stronger subcarrier orthogonality. Consequently, the impact of ICI and ISI in a multipath environment is effectively mitigated. Moreover, the jamming component of the joint signal can assist in channel estimation, leading to additional improvements in BER performance.  
Simultaneously, an increase in the number of UFMC sub-bands correlates with improved BER performance. The increased sub-bands contribute to less out-of-band leakage,  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Modulation mode & 4 QAM \\ Sub-band number & 32, 64, 256 \\ Number of multipath channels & 5 \\ \hline \hline \end{tabular}
\end{table}
Table 1: UFMC simulation parameter settings.  
Figure 10: Joint system communication performance results.  
facilitating the satisfaction of subcarrier orthogonality and ultimately enhancing BER performance. However, despite employing more UFMC sub-band partitions, the individual filtering of each subcarrier remains challenging, leading to some ICI and ISI jamming in UFMC chirp. This limitation prevents UFMC chirp from achieving better BER performance than FBMC.  
In radar signal processing, the FFT operates in the slow time domain, leading to enhanced SNR after coherent accumulation processing. When SNR exceeds 6 dB, the parameter modulation approach achieves a BER below \(10^{-4}\)[37]. Therefore, coherent accumulation processing is crucial for both FBMC chirp and UFMC chirp to achieve satisfactory BER performance, requiring a relatively high SNR. This ensures the joint system's capability to effectively jam while accurately completing communication tasks.
# Applying Knowledge Inference on Event-Conjunction for Automatic Control in Smart Building
## 1 Introduction
Finally, it hinders the development of machine learning methods to extract knowledge of event in an automatic manner, for realizing such as room occupancy detection, human motion tracking, and so on. In this paper, we present our proposal: a practical proposal of knowledge inference on event in IoT-enabled smart building environment. The proposal leverages the Building Topology Ontology (BOT) for constructing spatial graphs among sensors and spaces for further enabling conditional reasoning. In particular, considering the collected data is small, we utilized the Markov Chain Monte Carlo (MCMC) sampling method to approximate the time interval values of two correlated events. The proposal has been put into use in a real smart building environment. Several inference scenarios have been conducted. Moreover, the inference on users' waiting time revealed the effectiveness of automatic control on elevator for pursuing zero-waiting time. Hence, the primary contributions and novelties of this work can be summarized as follows:  
Figure 1: Scenario of user walking outside to inside the smart building with the sensors being triggered. Unified API development of IoT sensor network for event inference based on sensor-data collaboration in the smart building;
* Ontology-based graph model for constructing the spatial relations among sensors and space for further enabling automatic event extraction based on conditional reasoning;
* Inference engine, in which two types of models: FSMs (finite state machine) and BN (Bayesian Networks) have been proposed for event-mapping. Further, Markov Chain Monte Carlo (MCMC) model has been utilized for enhancing the accuracy of sampling the small-size dataset of time-interval values. * Usage scenario of automatic control on elevator control has been conducted for evaluation. The numerical results demonstrate the potential and effectiveness of automatic control application based on knowledge inference in the smart building.
## 2 Overview of IEEE 802.15.4 Standard
### GTS Allocation Procedure  
The standard allocates CFP slots to only those nodes which are a member of the PAN and holds a short address. A node can determine the number of GTS required (\(GTS^{req}\)) to send its data (\(D\)), once it knows the slot capacity by knowing the value of SO, with the help of Equation (4).  
\[GTS^{req}=|D/SC| \tag{4}\]  
Here, \(SC\) is the slot capacity to carry maximum number of bits and is computed as:  
\[SC=960\times 2^{SO-2} \tag{5}\]  
Each GTS requesting node calculates \(GTS^{req}\) and send it to the coordinator in CAP. A GTS requesting frame is shown in Figure 3.  
PAN Coordinator receives GTS requests only in CAP. At the end of the CAP, it evaluates the GTS requests. If GTS requests are within the available slot limits, then it allocates GTS to all the GTS requesting nodes. In case, requesting GTS are more than 7, then the PAN coordinator scrutinizes GTS on a first come first serve basis. All the scrutinized nodes are informed about their allocated CFP slots with their starting and ending slot during the next beacon frame. An increase in successful nodes increases the length of the beacon frame that reduces the CAP length. PAN coordinator also ensures to maintain the minimum CAP duration, as it should not be less than _aMinCAPLength_ value. The scrutinized nodes retrieve information about their assigned CFP slots from the GTS descriptor field of the beacon frame.
# Towards Robust Representations of Spatial Networks Using Graph Neural Networks
## 3 Preamble  
We define important concepts in this section. Table 1 outlines notations and their definitions.  
**Definition 1**.: _Spatial Entity: A spatial entity \(\mathcal{S}=(\mathcal{M},\mathcal{N})\) is defined as an object that is embedded in space, where \(\mathcal{M}\) is a set of geo-coordinates that defines its bounds or location in space and \(\mathcal{N}\) is a set of real-valued features that describes \(\mathcal{S}\)._  
**Definition 2**.: _Graph Representation: We define a graph representation as \(\mathcal{G}=(\mathcal{V},\mathcal{E})\), where \(\mathcal{V}\) and \(\mathcal{E}\) denote the object set and relation set, respectively. The objects are mapped to types based on a function \(\varphi:\mathcal{V}\rightarrow\mathcal{A}\), the relations are mapped to types based on a function \(\psi:\mathcal{E}\rightarrow\mathcal{R}\). The **homogeneous** graph representation is one where \(|\mathcal{A}|=1\) and \(|\mathcal{R}|=1\) and the **heterogeneous** graph representation is one where \(|\mathcal{A}|+|\mathcal{R}|>2\)._  
**Definition 3**.: _Semantic Path: A semantic path \(\mathcal{P}\) is a path on an instance of a graph representation \(\mathcal{G}\), denoted in the form \(A_{1}\xrightarrow{R_{1}}A_{2}\xrightarrow{R_{2}}\ldots\xrightarrow{R_{l}}A _{l+1}\), that defines a composite relation \(R=R_{1}\circ R_{2}\circ\cdots\circ R_{l}\) between graph objects \(A_{1},A_{2},\cdots,A_{l+1}\) where \(\circ\) denotes the composition operator on relations._  
**Definition 4**.: _Network Schema: A network schema \(\mathcal{D}_{\mathcal{G}}\) defines the object and relational constraints for a graph representation \(\mathcal{G}=(\mathcal{V},\mathcal{E})\) which is a directed graph representation where the objects are mapped to types as \(\varphi:\mathcal{V}\rightarrow\mathcal{A}\) and the relations are mapped to types as \(\psi:\mathcal{E}\rightarrow\mathcal{R}\). A graph representation defined by a network schema is called an instance of that network schema._
# Collagen Nanoparticles in Drug Delivery Systems and Tissue Engineering
## 2 Methods of Collagen Nanoparticle Preparation
### Milling  
Collagen in the nano-scale can be produced through the process of milling. In this process, a polymer material is disintegrated into finer NPs by the application of mechanical energy. This method uses milling balls for carrying out the high energy mechanical collision for the polymer disintegration (Figure 7). It is an economical method to carry out the reduction of the size of the particle on a large scale of production [56]. Heat energy in the process is produced as a result of the kinetic and mechanical energy that exists in the vessel used for milling [57]. Due to this production of heat energy, the milling vessel has to be cooled in order to avoid degradation of the material or overheating. Collagen, being a material sensitive to temperature, is milled mechanically utilising liquid nitrogen to avoid denaturation from heat, at cryogenic temperatures (below approximately \(-150\) degree Celsius) [32]. Experiments were conducted to fabricate small-sized collagen NPs (average size: 200 nm) using the milling technique. Micron-scale collagen powder was collected and added into liquid nitrogen for half an hour. The cryo collagen was put in vacuum for 2 days to sublimate water from collagen. Freeze-dried collagen was then subjected to high energy milling to prepare very fine nano-scale collagen particles. For every milling round, the amount of freeze-dried collagen was 1:5 by weight ratio with milling balls in a milling container (120 mL volume). These collagen NPs have been looked into using cell culture tests with osteoblasts, and resulted in 30% enhancement of growth of the cell when compared to collagen particles in the micro scale [58].  
Figure 6: Self-assembly—Desolvation—Individual protein chains are dissolved in a solution at a Critical Solution Temperature which exceeds the Critical Micelle Concentration and leads to the generation of protein micelles during the nanosized aggregate formation, in the self-assembly method. In desolvation, NPs are fabricated by the addition of a desolvating agent to a protein solution which contains drugs.
# Cause Analysis and Preventive Measures against False Bottoms in Echosounder Data
## 2 Materials and Methods
### The Working Principle and Imaging Principle of the Echosounder  
The echosounder [20] operates by emitting sound signals in a directed manner through a transmitter and subsequently receiving echo signals. When the emitted signal encounters a target or object, it generates a significant echo signal [21]. By recording the intensity and time of the echo and implementing various data-processing steps, such as amplification, filtering, and denoising [22; 23; 24; 25], the echosounder can calculate the position and size of the target, as well as other relevant information. In echosounder imaging, the processed echo intensity data (dB) are depicted as a grayscale or thermal map, thereby generating a two-dimensional echosounder image. Each pixel in the image represents the reflection intensity of the target at the corresponding location, providing a visual representation of the target's shape, position, size, and other characteristics [26; 27].
## 3 Case Study
### Assessment of the Emissions Abatement at the Cold Start
The first one is related to the initial portion of a single exhaust manifold equipped with the EHC-POCS (B-curved mesh version), including the fluid region, the duct, and struts solid domains. An additional region is considered to mimic the washcoat deposition on the POCS structure and to obtain a pre-catalyst behavior. The first layer of cells next to the POCS structure is selected and employed to identify the washcoat region. The cold start boundary conditions are considered. The imposed potential difference profile is specified, so that the electrical heating corresponding to 38 V is active in the first six seconds of the cold start. As such, the beneficial effects of the selected heating strategy can be assessed. The second simulation is performed on the considered exhaust line by imposing, as inlet boundary conditions, the values of mass flow rates, temperatures and chemical species concentrations obtained by means of the first simulation. Accordingly, the effects of the EHC-POCS structure are accounted for in each exhaust manifold. The combination of the described simulations provides a preliminary assessment of the after-treatment system equipped with the EHC-POCS structures with a considerable reduction in the required computational cost. The third simulation refers to the B-Curved mesh, excluding the presence of the EHC-POCS structure. As such, the thermal inertia of the first portion of the exhaust manifold is evaluated. The obtained results, in terms of mass flow rates, temperatures, and chemical species concentrations, are employed as inlet boundary conditions for the fourth simulation. In particular, it consists of the exhaust line under investigation, evaluating the response and the thermal transient of the after-treatment system. The second and the last simulations can be consistently compared, providing the assessment of the effects of the EHC-POCS application. As suggested in [21], a standard reaction model was considered for all the studied catalysts (washcoat of the EHC-POCS, CAT1, and CAT2), being a reasonable choice for a preliminary analysis. Even though the laminar flow assumption is considered for the pressure drop evaluation, a turbulent model is expected to be required when the exhaust gases-POCS heat and mass transfer need to be properly addressed. The \(k\)-\(\omega\)-\(SST\) turbulence model was selected for all the described simulations. The employed computational grids were generated to be compliant with the \(y^{+}\) requirements for the turbulent simulations.
# The Study of Novel Self-Rewetting Fluid Application to Loop Heat Pipe
## 2 Materials and Methods
### Working Fluid Choices  
SRF formulations have the potential to enhance the heat transfer performance of LHP, so this paper focuses on finding the ideal SRF formulations to enhance the thermal transfer performance. In the literature [10; 11; 12], butanol, pentanol, hexanol, and heptanol aqueous solutions are shown to have the potential to enhance the heat transfer performance, but it is also mentioned that the higher the concentration, the better the heat transfer performance, among which the butanol 6% aqueous solution has the highest concentration. This paper searched for SRF with higher solubility, and the results of this analysis showed that 2-butanol, an isomer of Butanol, has a higher saturation concentration. In this experiment, it was used 2-butanol (10%, 15%, and 20%) as the formulation of SRF and the butanol 6% aqueous solution, and a surface tension measurement with temperature was conducted. The surface tension measurements were carried out with the temperature variation to measure whether the SRF has the characteristics of LHP heat transfer performance enhancement as described in the literature.
# Dynamic Instability Analysis of a Double-Blade Centrifugal Pump
## 3 Results and Discussion
### Pressure Pulsations of Impeller at Different Flow Rates  
Figure 13 shows the pressure pulsations of different monitoring points in impeller at different flow rates. There is no rotor-stator interference in the impeller flow channel, but unsteady flow phenomena such as flow separation, backflow, and stalls make the pressure pulsation characteristics in the impeller flow channel more complicated. Compared with the periodic pressure pulsation in the volute, the periodicity of the pressure pulsation in the impeller is obviously weakened. For the suction side of the blade (X1-X3), the pressure pulsation amplitude is relative stable and fluctuates in the range of \(\pm 0.5\). The change of flow rate has a slight effect on the pluses at X1-X3. However, for the pressure side of the blade (Y1-Y3), the amplitude of the pressure pulsation changes greatly due to the jet-wake effect. Especially, near the trailing edge of blade pressure surface (Y3), the amplitude of pressure pulsation is at the highest level.  
Figure 12: Flow velocity streamlines at mid-span of pump under different flow rates: (**a**) \(0.4Q_{\rm d}\); (**b**) \(0.6Q_{\rm d}\); (**c**) \(0.8Q_{\rm d}\); (**d**) \(1.0Q_{\rm d}\); (**e**) \(1.2Q_{\rm d}\).  
In order to reveal the spectrum characteristics of impeller at different flow rates, the typical point X3 and Y3 were selected for further spectral analysis. The spectra of pressure pulsation at X3 and Y3 are presented in Figure 14. For all the cases, the main excitation frequencies for the pressure pulsation at X3 and Y3 are impeller rotational frequency and blade passing frequency (BPF).  
Figure 13: Pressure pulsations of impeller at different flow rates: (**a**) X1; (**b**) X2; (**c**) X3; (**d**) Y1; (**e**) Y2; (**f**) Y3.
# Hybrid ARQ Scheme with Autonomous Retransmission for Multicasting in Wireless Sensor Networks
###### Abstract  
A new hybrid automatic repeat request (HARQ) scheme for multicast service for wireless sensor networks is proposed in this study. In the proposed algorithm, the HARQ operation is combined with an autonomous retransmission method that ensure a data packet is transmitted irrespective of whether or not the packet is successfully decoded at the receivers. The optimal number of autonomous retransmissions is determined to ensure maximum spectral efficiency, and a practical method that adjusts the number of autonomous retransmissions for realistic conditions is developed. Simulation results show that the proposed method achieves higher spectral efficiency than existing HARQ techniques.  
hybrid automatic repeat request (HARQ); autonomous retransmission; multicast service; feedback overhead; power saving +
Footnote †: journal: Sensors
###### Abstract
Its unique nanoscale size effects and effective polymer modification have attracted considerable interest, finding applications in nanohybrid materials, medical materials and catalysts [31; 32]. The inorganic structure present in the cage-type POSS has a high modulus, stiffness and spatial site resistance, which maintains the strength of the base polymers and also increases the glass transition temperature of the polymers. The introduction of POSS moieties into photoresist polymers shows potential as a novel method to improve the heat resistance of photoresist resins. In this study, two novel monomers including triphenylsulfonium \(p\)-styrenesulfonate (TPS-SS) and polyhedral oligomeric silsesquioxane-based methyl acrylate (POSS-MA),were polymerized through RAFT polymerization to synthesize the photoresist copolymer (denoted as PTBM) for DUV lithography. In this context, tBMA and MMA monomers can optimize the performance of the photoresist by allowing the formation of fine patterns at a high resolution, while also providing excellent mechanical properties and thermal stability. The POSS-MA monomer reduces acid diffusion and simultaneously enhances the thermal resistance of polymeric matrix in the photoresist and its adhesion to silicon substrates. The PAG-based monomer, TPP-SS, chemically bonded into the polymer backbone after RAFT polymerization, increases the loading of photoacid and improves the uniform distribution of PAG in polymer matrix, effectively reducing acid diffusion. The research work highlighted the controllable nature of RAFT polymerization and the reproducibility of photoresist by examining polymerization kinetics. Furthermore, the impact of incorporating POSS-MA on the thermal properties of the copolymer matrix was evaluated using thermal gravimetric analyzer (TGA), differential scanning calorimetry (DSC) and thermomechanical analyzer (TMA) analyses. Ultimately, scanning electron microscopy (SEM) validation confirmed that integrating photoacid units into the main chain of copolymer mers effectively minimized the acid diffusion effect. Thus, the POSS/photoacid included copolymers provide valuable guidance to the rational design of DUV and EUV photoresists.