esa-sceva/satcom-chunk-collection huggingface dataset:
## 5 Conclusions  
In an attempt to effectively compress dense point cloud data obtained from a 3D free-form surface during the real-time scanning measuring process, this paper presents a novel on-line point cloud data compression algorithm which has the ability to identify and eliminate data redundancy caused by geometric feature similarity between adjacent scanning layers. At first, the new algorithm adopts the bi-Akima method to compress the initial point cloud data obtained by 3D scanning measuring devices. Next, the data redundancy in the compressed point cloud obtained in the previous stage is further identified and eliminated, and then we can obtain the final compressed point cloud data. Finally, the proposed on-line point cloud data compression algorithm was tested in the real-time scanning measuring process and compared with existing methods (the chordal method and bi-Akima method). The experimental results have preliminarily verified the application feasibility of our proposed method in industrial environment, and shown that it is capable of obtaining high-quality compressed point cloud data with a higher compression ratio than other existing methods. In particular, it can tightly control the deviation within the error tolerance range, which demonstrates the superior performance of the proposed algorithm. This algorithm could be used in the data acquisition process of 3D free-form surface scanning measurement to replace other existing on-line point cloud data compression/reduction methods.  
All work with relation to this paper has been accomplished by the efforts of all authors. Conceptualization, Y.L. and Y.T.; methodology, Z.H.; software, Y.T.; validation, Y.M. and Z.H.; formal analysis, Y.T.; investigation, Y.M.; resources, Y.M.; data curation, Y.M.; writing--original draft preparation, Y.T.; writing--review and editing, Y.T.; visualization, Z.H.; supervision, Y.L.; project administration, Y.L.; funding acquisition, Y.L.  
This research was funded by the National Natural Science Foundation of China (Grant Nos. 51505310, 51435011), the Key Research and Development Program of Sichuan Province of China (Grant No. 2018 GZ0282) and the Key Laboratory for Precision and Non-traditional Machining of Ministry of Education, Dalian University of Technology (Grant Nos. JMTZ201802, B201802).  
The authors declare no conflict of interest.
## 2 Dataset  
The European Space Agency (ESA) Sentinel-1 is a polar-orbiting SAR satellite constellation mission, which was designed for long-term monitoring land and ocean, including two satellites (A and B) launched in the April of 2014 and 2016, respectively. The Sentinel-1 satellite carries a high-resolution C-band SAR instrument operating in four imaging modes: stripmap (SM) mode, interferometric wide swath (IW) mode, extra-wide swath (EW) mode and wave (WV) mode. The EW mode performs with a large width of 410 km and an incident angle ranging from 18.9\({}^{\circ}\) to 47.0\({}^{\circ}\), whose images are suitable for TC wind field investigation [12; 24; 26; 27]. The SAR data used in this study are the EW mode dual-polarization (VV + VH) Level-1 Ground Range Detected (GRD) Medium Resolution (MR) products, which were collected from the ESA Copernicus Open Access Hub database ([[https://scihub.copernicus.eu/](https://scihub.copernicus.eu/)]([https://scihub.copernicus.eu/](https://scihub.copernicus.eu/)), accessed date: 21 April 2021). In our dataset, there were 41 TC cases containing storm eyes observed from 2016 to 2020. To retrieve the wind field, SAR images were resampled from a pixel spacing of 40 m \(\times\) 40 m to 1 km \(\times\) 1 km.  
In order to investigate the relationship between wind distribution and TC motion vector, we collected 22 best tracks from the NOAA National Hurricane Center (NHC, [[https://www.nhc.noaa.gov/data/tcr/](https://www.nhc.noaa.gov/data/tcr/)]([https://www.nhc.noaa.gov/data/tcr/](https://www.nhc.noaa.gov/data/tcr/)), accessed date: 24 April 2021) for hurricanes over the Atlantic and Eastern Pacific, and 19 best tracks from the Joint Typhoon Warning Center (JTWC, [[http://www.metoc.navy.mil/jtwc/](http://www.metoc.navy.mil/jtwc/)]([http://www.metoc.navy.mil/jtwc/](http://www.metoc.navy.mil/jtwc/)), accessed date: 5 July 2021) for typhoons over the Western Pacific. The best tracks include some basic TC information, such as time, intensity and center location. The time difference between best tracks and SAR data is less than 3 h. Figure 2 shows the TC cases' locations and intensities provided by best tracks. Of note, the intensity is defined as the 1 min sustained wind with the closest time to SAR acquisition and represented by the Saffir-Simpson hurricane wind scale. According to the best track data, the storm with the highest intensity is Typhoon Halong (2019), which reached 160 knots, i.e., 82.2 m/s.  
Figure 2: The locations of 41 TC cases investigated in this work and their categories (Saffir–Simpson hurricane wind scale) provided by the best tracks from the NHC and the JTWC.
# Effect of Different pH Beverages on the Color Stability of Smart Monochromatic Composite
###### Abstract  
Omnichroma is a smart monochromatic material and is believed to attain the shade of the surrounding tooth structure in which it is placed. However, the color stability of this material is unknown. Therefore, this study was conducted to evaluate the effect of different pH beverages on the color stability of the Omnichroma composite and its comparison with micro-hybrid composite resin. Sixty extracted human maxillary premolars of different shades, viz. A2, A3, B2 and B3, were selected in equal numbers. A Class V cavity was prepared on the buccal and palatal sides of each tooth. After the cavity preparation, etching of the cavity was performed with 35% phosphoric acid followed by bonding. The prepared cavities were then filled with Omnichroma composite resin on the buccal side and Filtek Z250 composite on the palatal side. The baseline color measurements of all tooth samples were performed by a spectrophotometer. The teeth were then divided into three groups, the Pepsi group, coffee group and milk tea group. Five teeth from each shade, viz. A2, A3, B2 and B3, were immersed in 10-mL of Pepsi, coffee, and milk tea for 14 days. After the completion of the 14 days, the teeth were rinsed and kept in distilled water for 24 h. Finally, a spectrophotometer was used to calculate the color alteration value \(\Delta\)E. Mean difference in \(\Delta\)E values of the samples before and after immersion in different beverages was calculated and analysed by SPSS 25. One-way ANOVA test was applied to compare groups. Further stratification was performed using the Post-Hoc Tukey test. Samples immersed in milk tea showed a statistically significant difference (\(p<0.05\)) in A2, A3, and B2 shades of the OM-milk tea group in comparison with the FT-milk tea group. In summary, the immersion of teeth in beverages with a different pH and colorants showed an apparent alteration in the color of both the smart monochromatic and micro-hybrid composites. Hence, the type of resin composite material should be selected wisely depending on the patient's drinking and social habits.  
color stability; dentistry; micro-hybrid composite; omnichroma; restorative; smart monochromatic material +
Footnote †: journal: Applied Sciences
## 2 Monitoring of Nutritional Status in CKD Patients: Affected Parameters
### Anthropometric Indicators  
Anthropometric methods may be validated for use in HD patients, although alone are not sufficient and should be associated with the other parameters described. In addition to body mass index (BMI), lean muscle mass should also be taken into account, particularly when values of <25 kg/m\({}^{2}\) are detected and reduction in average arm circumference is 10% below the 50 th percentile of the reference population. Mid-arm circumference, triceps skin-fold thickness and mid-upper arm muscle circumference were measured. Waist circumference was measured above the iliac crest, at the level of the hips and on the most relevant part of the buttocks; these parameters also correlate with cardiovascular risk. In addition to these findings, plicometry was applied to measure thickness of the skin on the arm. Finally, the assessment of muscle strength by means of specific tests is fundamental, although strength may be significantly influenced by age, cognitive status, smoking, alcohol intake and sedatives [41; 42; 43; 44]. Body weight and consequent BMI should always be assessed prior to dialysis sessions in view of the potential for hyperhydration frequently manifested in HD patients. Subjective global assessment (SGA) is a widely-used sensitive technique used to assess nutritional status and is better correlated with health-related physical and mental quality of life aspects in HD patients [45; 46; 47]. The so-called \"BMI paradox\", i.e., the association of high BMI with inflammation observed in dialysis patients, should also be taken into account. Recent data suggest a cross-sectional association of high BMI or abdominal adiposity with inflammation produced through alteration of circulatory cytokines, sequestration of uremic toxin in adipose tissue, and endotoxin-lipoprotein interaction, coronary artery calcification myocardial injury, a more proatherogenic profile in terms of inflammatory markers and adipokine expression, lower body composition reserves, and lower physical ability and decreased survival [48; 49]. To date, therapeutic results obtained with regard to \"sarcopenia obesity\" have been disappointing. Weight reduction obtained through conservative or metabolic (bariatric) management and weight loss during dialysis treatment should be avoided [50; 51]. Maintenance of body weight by means ofadequate nutrition and physical activity is mandatory in preventing weight loss or onset of sarcopenia; body composition assessment and functional testing (handgrip strength, gait speed) should be carried out. Structured exercise programs have been proven to increase muscle mass and functional outcomes. Furthermore, high BMI (\(>\) 30-35) is associated with higher risk of transplant complications.
# Future of IoT Networks: A Survey
## 4 Research Challenges of the IoT Network
### Heterogeneity of Network Technologies  
In IoT, it is prevalent that the devices are installed with different types of network protocols. Each network protocol has different service types and network conditions. To overcome the challenge of integrating different network protocols, there have been efforts to integrate heterogeneous networks [54; 55; 56]. Further, direct communication among the devices is not always supported even if the devices are collocated and use the same radio technology [57]. The IoT-A communication protocol model was proposed by [58] and accepts standards such as Constrained Application Protocol (CoAP), User Datagram Protocol (UDP), Internet Engineering Task Force IPv6 Routing Protocol for Low-Power and Lossy Networks (IETF RPL), IPv6 over Low-Power Wireless Personal Area Networks. (6 LoWPAN), IEEE 802.15.4e, and IEEE Std 802.15.4-2006. However, there is no standard or exemplary technology that can support different network protocols. Inter-operability encompassing these network protocols is expected be a major challenge for constructing the IoT network. Generally, a network translation gateway is required to connect devices that employ different communication  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**References** & **CDN\({}^{\,1}\)** & **IP-Based** & **User-Demand** & **Synchronization-Ization** & **Replica Placement** & **Additional** \\ \hline [48] & server-farm & O & O & X & O & QoE-based [2], machine-learning \\ [51] & hybrid & O & X & O & X & synchronizing CDN edge server \\ [52] & hybrid & O & X & X & O & economic modeling-based \\ [50] & server-farm & O & X & X & O & popularity-based \\ \hline \hline \end{tabular} \({}^{\,1}\) Content Distribution Network (CDN); \({}^{\,2}\) Quality-of-Experience (QoE).  
\end{table}
Table 3: Comparison of service-oriented network technologies.  
Figure 2: The concept of content distributed network. (**a**) The procedure of current content request; (**b**) The procedure of content-distributed network.  
protocols [59; 60]. Nonetheless, forcing all communication through the gateway may result in overhead problems. These issues with integrating various network protocols must be addressed within the IoT network. Table 4 compares the techniques related to support heterogeneity.
# A Transfer Reinforcement Learning Approach for Capacity Sharing in Beyond 5G Networks
## 4 Performance Evaluation  
This section evaluates the proposed TRL approach by assessing its performance in a multi-cell and multi-tenant scenario, where a new cell is deployed to increase the scenario capacity. First, the considered scenario is presented in Section 4.1, and the training assessment methodology and Key Performance Indicators (KPIs) are defined in Section 4.2. Then, in Section 4.3, the assessment of the training performance of the TRL is conducted by first focusing on the considered scenario and then extending the study to a wider range of RAN deployments with different sizes. Finally, an analysis of the performance achieved by the trained policies according to the TRL approach during their inference is included in Section 4.4.
## 2 Real-Time City-Scale Nonlinear Time-History Analysis  
### Framework  
The proposed framework to conduct the real-time city-scale time-history analysis and loss assessment is illustrated in Figure 1. The corresponding procedures are as follows:  
1. Obtaining the real-time ground motion records from the seismic stations;
2. Establishing the building inventory database for the target region;
3. Conducting the city-scale nonlinear time-history analysis to predict the seismic damage of the target region; and
4. Performing the regional seismic loss prediction to assess the seismic economic loss and repair time of the target region.
# EV Charging Behavior Analysis Using Hybrid Intelligence for 5G Smart Grid
## 2 Smart Grid Network Architecture with EV Access
### The User Layer  
The user layer is the lowest level and it is composed of various types of end-users. The end-users are comprised of all vehicle-to-grid system entities and electric vehicle users that need to use the services in service layer. The end-users can initiate a service request to the service layer through the service access point (SAP) using the communication device. Accordingly, they will also receive responses from the upper layers through a similar SAP.  
The data collected by sensors on EVs are diverse and plentiful. It includes the user's driving behavior as uploaded by smart devices and wearable devices, battery security data collected by the battery sensors, and EV charging information uploaded by the charging station. This makes it easy to collect EV user behavior information, including the distance of the trip, the connection and disconnection times of the charger, and the battery state of charge (SOC). These data could be used to analyze the behavior of EV users through artificial intelligence algorithms.
## 5 AI-Empowered Communication with Perceptual Constraint  
The advances in generative modeling discussed thus far have significant implications for communication systems, particularly in scenarios where high perceptual quality is essential for downstream tasks. These models can be deployed at various points in the communication pipeline to enhance both compression efficiency and reconstruction quality.  
Recent years have witnessed substantial progress in applying machine learning algorithms, particularly generative modeling, to communication networks, driven by their capacity to enhance perceptual quality. Downstream tasks, ranging from image reconstruction [13] to steganography [51], are highly sensitive to distribution and can be executed at the wireless edge using neural networks. Learning-based methods can more easily account for and optimize perceptual qualities as the training of these neural network models inherently addresses the distribution of the output. Thus, perceptual requirements are both natural and essential for AI-empowered communication systems.
## 2 Research Program
### Research Methodology  
This research was planned to evaluate the influence of polypropylene fibre content on the fresh mix factors and mechanical assets of PPHPSCC. In order to obtain parameters of workability, the L-box and slump flow examinations were performed in accordance with  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Designation** & **Cement** & **GGBS** & **Quartz Sand** & **Gravel** & **Water** & **HRWA** & **PP Fibre** \\ \hline HPSCC & 350 & 300 & 980 & 400 & 210 & 19 & — \\ PPHPSCC-0.025 & 350 & 300 & 980 & 400 & 210 & 19 & 0.23 \\ PPHPSCC-0.05 & 350 & 300 & 980 & 400 & 210 & 19 & 0.46 \\ PPHPSCC-0.075 & 350 & 300 & 980 & 400 & 210 & 19 & 0.68 \\ PPHPSCC-0.125 & 350 & 300 & 980 & 400 & 210 & 19 & 1.14 \\ PPHPSCC-0.25 & 350 & 300 & 980 & 400 & 210 & 19 & 2.28 \\ \hline \end{tabular}
\end{table}
Table 2: HPSCC and PPHPSCC mixture proportions (kg/m\({}^{3}\)).  
Figure 1: Polypropylene fibres used in the tests.  
Figure 2: Diagram of PPHPSCC mixing process.  
the European Guidelines for SCC [41]. The L-box experiment was made using an L-shaped vertical box. Initially, the vertical part of the L-box was filled with the mix. After 1 min, the gate was raised to allow its passing through three steel rebars and fill the horizontal part of the equipment (see Figure 3). The distance measurements were made at both ends of the box in six evenly spaced places between its upper edge and the concrete level. In the next step, the average distance of the mix from the top of the box was calculated and then the depth ratio was determined. This ratio corresponds to the mix's passing ability (PA). During the slump flow test, we measured the maximum flow diameters in two directions and the time (T\({}_{500}\)) in which the PPHPSCC mix reached a diameter of 500 mm.  
The mechanical properties of PPHPSCCs were established at 7 and 28 days of maturation in water. The strength under compression test was performed using a testing machine of 3 MN capacity in accordance with PN-EN 12390-3 [42] on cubes of 100 \(\times\) 100 \(\times\) 100 mm. Each cube was tested up to failure. The load rate was 0.5 MPa/s. Cubic samples (12 for each mix) were tested at two ages of maturation. Then, the average value of this strength was taken as the compressive strength of this mix. The PPHPSCCs split tensile strength was examined using the testing machine according to PN-EN 12390-6 [43]. Specimens were loaded at a rate of 0.05 MPa/s. Cubes of 100 \(\times\) 100 \(\times\) 100 mm size (12 for each mix) were tested for each mix at 7 and 28 days of curing. The mean value of this strength was taken as the splitting tensile strength. The bending test of PPHPSCCs was performed at three-point loading scheme with using a hydraulic machine in accordance with PN-EN 12390-5 [44]. Prismatic specimens were loaded at a rate of 0.05 mm/min. 100 mm \(\times\) 100 mm \(\times\) 500 mm size prismatic specimens (6 for each mix) were examined at two curing ages, as well as the mean value of the flexural strength was determined for each testing mix.  
Figure 3: Slump flow diameter measurement (**a**) and height of L-box filling (**b**).
# Effect of Built Environment Factors on Pedestrian Safety in Portuguese Urban Areas
Several studies in the field of road safety have already been conducted as part of the effort to find solutions for the problem of traffic crashes involving vulnerable road users such as pedestrians [6; 7]. The studies show that the main factors directly related to exposure to risk and the frequency and severity of crashes are the pedestrian traffic volume, the vehicular traffic volume, and the speed of traffic operation [8; 9; 10; 11]. However, there is still a lack of analyses with a broader outreach encompassing the influence of factors associated with the pedestrians' spaces used for their mobility [12; 13]. Not all environments are equally safe, and various characteristics may prove to be related to different levels of the risk to pedestrians' safety [12; 14]. The present paper aims to identify factors related to the built and road environments in addition to the characteristics of the traffic that influence pedestrian safety in Portuguese urban roads, using a transversal study (aggregated data) and a longitudinal study (disaggregated data). The environmental factors are classified into three groups: built environment, pedestrian infrastructure, and road infrastructure. Within each group, the factors were identified by developing crash prediction models using two modeling techniques: Zero-Truncated Negative Binomial (ZTNB) and Generalized Estimating Equations (GEE). These techniques were selected due to the limitations of the database (see Section 3.2). To develop the models, the Portuguese National Road Safety Authority (_Autoridade Nacional de Seguranca Rodovaria_--ANSR) made available a database with information on all the road crashes registered for the period from 2009 to 2015. The complete database also contains a set of specific variables referring to the road network characteristics selected for this study, which are located in the Portuguese counties of Braga and Guimaraes.
# InnCube--A Wireless Satellite Platform to Demonstrate Innovative Technologies
## 2 Mission
### Orbit Design
#### 2.1.2 Space Debris Mitigation Guidelines  
IRAS as an institute researching the subject of space debris, the Space Debris Mitigation guidelines are an important aspect in the design and operation of a satellite. The applicable guidelines include deorbiting not later than 25 years after the end of operational life, a re-entry burn up above 15 km, a minimization of risk of explosion and no generation of space debris.  
The analysis tool DRAMA (Debris Risk Assessment and Mitigation Analyses) [5; 6] was used for the calculation of maximum lifetime after end of operations and to confirm the maximum possible orbital altitude. The simulation resulted in a natural orbital lifetime of 17 years at an orbital altitude of 576 km (using the latest Two Line Elements (TLE) of the highest Starlink satellite [7]). Thus, the space-debris avoidance guidelines are met by a 5% margin. The simulated individual components demise between an altitude of 75 km and 80 km.  
The current satellite design does neither include any deployables nor extendable structures, except for the ultra-high frequency (UHF) antennas. In addition, the operation  
Figure 1: left.: Global Navigation Satellite System (GNSS) in orbit reception geometry [4]; right.: Visibility of GNSS satellites in different orbital altitudes; top: Global Positioning System (GPS); Middle: Galileo; Bottom: combined [3].  
and evaluation of the scientific payloads can be expected to provide highly accurate position data and reduce collision risk where appropriate. Thus, the requirements for minimizing the risk of explosion and no further creation of space debris are addressed by the satellite, mission design, and adherence to the CubeSat standard.