esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Discussion
The results of this study show a significant reduction in the milling duration between feed rates of 2000 mm/min and 3500 mm/min. This suggests that the feed rate affects the milling duration. Additionally, there was no significant difference in the milling duration between feed rates at intervals of 500 mm/min. Therefore, the feed rate should be adjusted at increments of 1000 mm/min. However, in practice, desktop dental milling machines, including the machine used in this study, do not always operate at the theoretical feed rategiven the small workspace and the insufficient number of strokes to output the set feed rate. Therefore, it is necessary to consider an upper limit while setting the feed rate. This study has some limitations. The first limitation is the setting of the milling conditions. The present study focused on the number of spindles and feed rate to compare the effects of 12 different combinations on accuracy and milling duration. Other various machining conditions such as cutting depth and step-over may affect the accuracy and milling duration. The actual milling process for fabricating complete dentures involves additional steps and various tools. In addition, factors such as shape, material, and coating may affect the accuracy and speed of the machining process. Therefore, it is necessary to investigate other factors related to machining to determine the optimal denture milling conditions. Furthermore, milling machines other than that used in this study are commercially available in the market. Considering the possibility that the results of this study may not reflect the performance of these machines, the evaluation of other dental milling machines is also necessary. Based on the results of this study, future studies are required with the aim of fabricating complete dentures to verify whether milling can be performed within a short duration and with a high accuracy at any step. Additionally, this study was conducted to determine its clinical utility. Further studies are warranted to determine the optimal shape and material of the tool used for milling the PMMA disk for denture base fabrication.
# Adaptive Polling Medium Access Control Protocol for Optic Wireless Networks
## 5 Experimental Setup and Numerical Results
### Average Delay  
In Figure 4(a),b we present our numerical results considering average delay as a function of network size and network load. Figure 4(a) shows the delay against network size, where network size ranges from 1 to 10 VLNs. Numerical results suggest that APMAC performs better than MT-MAC in terms of average delay. The DFK-MTU algorithm and non-contention approach we adopted in APMAC protocol are key factors for the low average waiting time recorded in Figure 4(a). The average delay increased when network size increased for both APMAC and MT-MAC because when there are many VLNs in a network, resources arbitration between VLNs and VLAP consumes a lot of time. Figure 4(b) demonstrates average delay as function of network load for both APMAC and MT-MAC protocols. Numerical results in this context suggest that delay increases with respect to network load. This is due to the fact that each VLN holds resources longer when there are many packets to be transmitted. However, APMAC protocol performs better than the MT-MAC protocol in this case.
# Vegetation Dynamics and Recovery Potential in Arid and Semi-Arid Northwest China
## 4 Materials and Methods  
### Study Area  
The arid and semi-arid regions of China located in the northwest, north of the Great Wall and Kunlun Mountains, including Xinjiang, Inner Mongolia, northern Ningxia, western Gansu, and the Qaidam Basin in Qinghai. These areas cover about one-third territory of China. To maintain administrative consistency, this study selects five provinces or regions namely Xinjiang,., Gansu, Inner Mongolia, Ningxia, and Qinghai--referred to as the northwestern region. The study area spans 31\({}^{\circ}\)36\({}^{\prime}\) N to 53\({}^{\circ}\)23\({}^{\prime}\) N and 73\({}^{\circ}\)40\({}^{\prime}\) E to 126\({}^{\circ}\)04\({}^{\prime}\) E, covering approximately 4.06 million km\({}^{2}\) (Figure 14a) [55]. The northwestern region selected for this study spans three of topographic steps of China, featuring a wide range of elevations and complex landforms. The main terrains in this area include plateaus, basins, and mountains, such as the Qinghai-Tibet Plateau, Loess Plateau, Inner Mongolia Plateau, Tarim Basin, Qaidam Basin, Junggar Basin, Tianshan Mountains, Kunlun Mountains, and Qilian Mountains [56]. The northwestern region is located in the hinterland of Eurasian continent, making it difficult for moist air from the oceans to reach it. The region is influenced by the interaction between the summer monsoon, westerlies, and plateau winds, resulting in a predominantly continental monsoon climate. It is characterized by aridity, low rainfall, long sunshine duration, high evapotranspiration, frequent sandstorms, and significant dryness. As a result, the region faces severe water scarcity and fragile ecosystems, making it not only a typical resource-limited area but also one of the regions most sensitive to global climate change.
# Natural Convection of Dusty Hybrid Nanofluids in an Enclosure Including Two Oriented Heated Fins
## 5 Conclusions  
Numerical simulations have been performed to study the natural convection flow of dusty hybrid nanofluids inside shallow cavities; those include two rotating heated fins. One of the fins rotates in the clockwise direction and the other rotates in the opposite direction (anticlockwise). This phenomenon was presented by two systems of partial differential equations for the hybrid nanofluid phase and dusty phase. Two SIMPLE algorithms were performed to evaluate the pressures for the hybrid nanofluid and dusty phases. The main results of this simulation can be summarized as follows:  
1. There are minimum values of the local Nusselt number that occur at the center of the top wall. Also, the increases in the fins lengths enhance the rate of heat transfer regardless of the values of the inclination angle.
2. For the low values of the lengths of the fins, the vertical fins are the best for the heat transfer compared with the rotating fins.
3. A clear reduction in the heat transfer rate is obtained as a ratio of the mixture densities increases. Also, like the effects of the mixture density ratio, the increase in the dusty parameter reduces the average Nusselt number.
4. A good support in profiles of the average Nusselt number is observed as the nanoparticles' volume fraction increases.
5. The maximum values of the streamlines and dusty velocity components are diminished as values of the nanoparticles' volume fraction decreases.  
**Funding:** This research was funded by King Khalid University, grant number R.G.P1./147/40.  
**Acknowledgments:** The authors would like to extend their appreciations to the Deanship of Scientific Research at King Khalid University for funding their work through research groups program under grant (R.G.P1./147/40).  
**Conflicts of Interest:** The authors declare no conflict of interest.  
**Nomenclature**  
\(C_{p}\) specific heat  
\(D_{s}\) ratio of the mixture densities  
g gravitational acceleration, m/s\({}^{2}\)  
\(k\) thermal conductivity, W m\({}^{-1}\)K\({}^{-1}\)  
\(L_{1},L_{2}\) lengths of left and right fins  
\(Nu\) Nusselt number  
\(P\) pressure, N/m\({}^{2}\)  
\(Pr\) Prandtl number  
\(\dot{Q}\) heat generation parameter  
\(Ra\) Rayleigh number  
\(s1,s2\) fin location in the enclosure  
\(T\) temperature, K  
\(t\) time, s  
\(u\), \(v\) dimension velocity components, \(\frac{\mathrm{m}}{s}\)  
\(x\), \(y\) Cartesian coordinates, m
# Mechanism and Characterization of
## 1 Introduction
Therefore, it is of great significance to design NR composites with a simple preparation process and good dispersion using a combination of experiments and computational simulations. Molecular dynamics (MD) simulations have become an effective computational tool for studying the physical behavior and molecular interactions of materials at the atomic scale. They can complement experimental research and provide a strong theoretical basis for studies. MD simulations have proven to be suitable for investigating polymer material properties, including their binding energies and intermolecular interaction forces [22; 23; 24; 25; 26; 27]. The application of molecular dynamics simulations in filler dispersion studies is very important because they provide a deep understanding of the interaction between the filler and the matrix and reveal the dynamic processes of distribution, aggregation, and movement of the filler at the molecular level. Therefore, a comprehensive study combining experimental methods and MD simulations is necessary to evaluate the applicability of NR enhanced with dual-component fillers. MWCNTs have a very high surface area and excellent electrical conductivity, leading to excellent interfacial bonding with SiO\({}_{2}\). Due to the strong van der Waals forces and \(\pi\)-\(\pi\) interactions, carbon nanotubes can effectively promote the dispersion of the fillers and form strong and effective contacts with the SiO\({}_{2}\) surface, which enhances the stability and homogeneous distribution of the fillers in the matrix. Compared with single fillers or other traditional two-component fillers (e.g., the combination of carbon black and SiO\({}_{2}\)), the composite system of MWCNTs and SiO\({}_{2}\) is capable of achieving a more homogeneous dispersion and reducing aggregation phenomena at the microscopic scale. In this study, SiO\({}_{2}\) and MWCNTs were used as reinforcing fillers, with NR as the matrix. The aim was to enhance the interfacial bonding between the NR matrix and the fillers by employing dual-component fillers to reinforce the NR composites and to improve the dispersion of these reinforcing fillers. NR composites with excellent mechanical properties and dispersion abilities were prepared using a solution blending method. The dispersion of the dual-component fillers within the NR was analyzed through dynamic mechanical analysis (DMA), rubber process analysis (RPA), and field emission scanning electron microscopy (SEM). Moreover, MD simulations further verified the consistency between the experimental results and molecular dynamics modeling. This research enables the combination of MWCNTs and SiO\({}_{2}\) with potential for applications in high-performance tires, electronics, and high-temperature and chemical-resistant sealants.
## 3 Results and Discussions
### Injector Angle (\(\alpha\)) Study  
One of the important geometric parameters of the stenter machine is the injector angle. This geometric parameter plays a key role in determining the angle at which air contacts the fabric surface. Currently, injector channels with a 30\({}^{\circ}\) injector angle are used in the stenter machine in the company. Reducing this angle is expected to improve the contact between air and fabric, leading to better cooling performance compared to increasing it. Therefore, three different angles of 0\({}^{\circ}\), 10\({}^{\circ}\), and 20\({}^{\circ}\) were determined. The results predicted by CFD simulations to reveal the cooling performance for the four different injector angles are presented in Figure 7b. Following the cooling process (t = 1.57 s), Figures 10 and 11 show the temperature contour of fabric surfaces and the streamlines on the surface located in the upper injector channel for different injector angles, respectively. If these figures are examined together, with an increase in the injector angles, the fabric surface temperature at the end of the cooling process increases. The cooling performance is adversely affected by the increased angle between the horizontal plane and the injector hole plane. In the case of contacting air with the fabric vertically (\(\alpha\) = 0\({}^{\circ}\)), more effective cooling performance can be reached. If the injector angles are higher than 0\({}^{\circ}\), the air injected through injector holes cannot directly contact the fabric. Some air may exit the fluid domain without coming into contact with the fabric.  
Figure 10: Contours of temperature distributions of the fabric for different injector angle values at 1.57 s.
## 4 Results and Analysis
### Comparative Testing of Transmission Mechanisms and Results Analysis
#### 4.2.2 Synchronization Control Delay Distribution  
The status-byte-assisted RDMA transmission mechanism utilizes RDMA Read, which blocks the sending thread during the transmission of synchronization data. This approach results in relatively stable synchronization control latency. In contrast, the sliding window transmission mechanism uses RDMA Send, with the receiver sending synchronization data. This approach does not block the sending thread, and thus, it makes transmission latency susceptible to sender-induced fluctuations and leads to greater variance. Figure 11 illustrates the distribution of synchronization control latency versus the number of transmissions: (a) the sliding window RDMA transmission mechanism and (b) the status-byte-assisted RDMA transmission mechanism. As can be seen from Figure 11, under identical test conditions, the status-byte-assisted transmission mechanism exhibits consistent latency with significantly smaller fluctuations compared to the sliding window mechanism.  
Figure 10: Comparison of synchronization control latency of various transmission mechanisms with different number of memory blocks.
# A Novel Multi-Server Federated Learning Framework in Vehicular Edge Computing
## 4 Proposed MS-FL Framework  
In our proposed MS-FL framework for vehicular edge computing, the learning process is divided into two main phases: proposed inter-server model aggregation and intra-server model training. The intra-server training phase is further segmented into vehicle-level training followed by local model aggregation at each server, similar to [5]. These phases occur within a single time interval as the states of both servers and vehicles transition from time step \(\mathrm{t}\) to \((\mathrm{t+1})\).  
At the beginning of time step \(t\), each server broadcasts a description of its current model--including any specific requirements (e.g., an image classification network for traffic sign detection)--to nearby servers and the vehicles within its coverage. Servers with models that match these requirements respond by sending their matching model parameters, along with identifiers such as their RSU ID, to the requesting server. Concurrently, vehicles that meet the server's criteria (including factors like required data types, data sizes, computational capabilities, and available bandwidth) send positive feedback along with their unique vehicle identification number (VIN). Based on these responses and available communication resources, the server selects \(m\) clients to participate in local training. The server then transmits its current model, \(\mathrm{w}^{\mathrm{(s)}}(\mathrm{t})\), to the selected vehicles to initiate the vehicle-level training phase.
## 3 Results
### Evaluation Metrics  
#### 3.1.1 Tracking Evaluation  
The three MOT methods, StrongSORT, DeepSORT, and ByteTrack, are compared in terms of lost-tracking rate and the number of ID changes. The lost-tracking rate is calculated as follows:  
\[Ltr=\frac{Nnd}{Nf} \tag{4}\]  
where \(Ltr\) is the lost-tracking rate, \(Nnd\) is the number of frames without detection, and \(Nf\) is the total number of frames.  
A higher lost-tracking rate means fewer frames are being tracked. Therefore, the MOT method with the lowest lost-tracking rate is preferred.  
Moreover, the MOT models should ideally continue tracking a certain subject with a constant ID number. However, the tracker may reassign a new ID number to the same subject once the subject is re-tracked after a break, which means the tracker recognizes the subject with a different identification number. More frequent ID changes or identity-switching errors indicate the tracker has a worse ability for tracking and can lead to incorrect interpretations of object behavior and interactions [55]. Thus, the MOT method with fewer ID changes is superior.
## 2 Vibration Isolation System of the DCM
\[\omega_{n}=\sqrt{\frac{k}{m}} \tag{1}\]  
\[\frac{X}{A}=\frac{\sqrt{1+\left(2\frac{\chi}{\omega_{n}}\frac{\omega}{\omega_{n }}\right)^{2}}}{\sqrt{\left[1-\left(\frac{\omega}{\omega_{n}}\right)^{2} \right]^{2}+\left(2\varsigma^{2}\frac{\omega}{\omega_{n}}\right)^{2}}} \tag{2}\]  
Reducing the natural frequency of the system effectively isolates the external vibration excitation, which can be achieved by increasing the mass of the DCM or by reducing the stiffness of the frame connection. For the DCM, due to the limitation of the mass of the base frame, reducing the stiffness is a more practical way to achieve the same natural frequency; therefore, a quasi-zero stiffness isolation system is chosen for the frame vibration isolation design. The operating principle of a QZS system involves using a positive stiffness component to support the weight of the isolated component, while a negative stiffness component counteracts the positive stiffness during vibrations. In static conditions, the system has sufficient static stiffness to maintain stability, while, during dynamic processes, the stiffness approaches zero, maintaining a low natural frequency. The design focus of QZS systems lies in the negative stiffness element, commonly implemented with spiral compression springs or compression-bent beams or leaf springs (LSs). Due to the spatial constraints of the DCM and the requirement for a thin isolation system in a high vacuum environment, only an LS structure can meet these demands. Therefore, using buckled LSs with fixed ends as the negative stiffness element is ideal for such applications as it involves no moving parts and requires no lubrication, making it suitable for vacuum environments. Although this form of quasi-zero stiffness isolation is only effective for vibrational excitation in one direction, the core element of the DCM is mainly sensitive to longitudinal displacements, so quasi-zero stiffness isolation can be applied to this scenario. In the field of QZS, the traditional method of numerical calculation of the negative stiffness of LSs in the form of fixed ends suffers from a large error, which grows linearly with the change in the elastic modulus of the material. Therefore, academics usually carry out theoretical calculations when using low modulus of elasticity 3D printed plastics to make LSs, for example, the traditional calculation method is widely used in the study  
Figure 5: Frequency ratio and transmissibility. of energy-absorbing metamaterials with honeycomb structure. However, for metallic LSs, due to the large calculation errors, designers typically rely on finite element simulations combined with vibration experiments for accurate design. In practical applications, metallic materials are more suitable for LS production. Hence, this paper proposes a new method for calculating negative stiffness values, significantly improving the accuracy of these calculations.
# Power-Split Hybrid Train Configuration Design Based on a Single-Row Star Row
## 4 Analysis and Design of the Configuration Scheme  
### Design Analysis When Using Scheme (b)  
A hybrid box must use power-switching components to provide seamless switching between operating modes and to guarantee an acceptable spatial structural layout, in addition to meeting the dynamics requirements for train operation. In this study, two input power-split configurations were used to build three hybrid box structures. Figure 6a depicts the hybrid power-coupling mechanism scheme created in accordance with plan (b).  
The power of the MG1 motor is transferred to the sun gear by one gearing stage, the output shaft of the MG2 motor is connected to the planetary carrier, and the engine power in this scheme must be transferred to the gear ring through two parallel stage gears.  
This scheme has a greater variety of operating mode types and stricter criteria for mode-switching control that make implementation more challenging. The number of parallel-stage gears is relatively large, which results in a low system efficiency, while the structure is complex and does not meet the spatial arrangement requirements; thus, this structure was excluded.  
Figure 5: Acceleration time (0–100 km/h) for the feasible power-split configurations.
# The Development of Key Technologies in Applications of Vessels Connected to the Internet
## 2 Internet of Vessels Architecture  
As a product in the global information era, the Internet of Things is a very important component of information technology. Based on the frame of the IoT (Internet of Things) technology, the ship's specific characteristics and the application environment, the internet of vessels is proposed. In 1998, the USA developed a kind of integrated service system called the Intelligent Website System (IWS) which contained a ship Automatic Identification System (AIS), data exchange system, navigation system and information network system [3]. At the beginning of the 21 st century, the European Union conducted integrated information services for the inland waterway, the River Information Services (RIS), which is a prototype of the IoV [4; 5; 6]. The existing structure of the IoV is shown in Figure 1, which consists of vessels, island base stations, a climatic observation system, communication satellites, buoys, wireless transmitting and receiving devices, and the command system.
# Lithium Metal: The Key to Green Transportation
## 4 Discussion
### Advantages of Lithium-Ion Batteries  
The development of new battery components that will considerably boost the real-world performance of LIB has been the main focus of research in the field of battery chemistry. Over the last decade, the cathode, anode, binder, and polymer's fundamental performances have been independently improved through meticulous chemical composition alteration.  
A new generation of electrochemical generators was created in the middle of the 1960s by using a very pure lithium-metal foil on an anode and a lithium salt solution as an electrolyte. The experimental development of LIB was in parallel with many other batteries such as nickel-metal hydride (Ni-MH) and nickel-cadmium (Ni-Cd) batteries. However, the performance of lithium batteries was far better than that of other types. That advantageous performance lies in the lithium ions Equation (2) produced through a straightforward reaction that releases one electron through the external circuit and introduces one ion into the cathode's porous structure [88] (Figure 11).  
\[Li\to Li^{+}+e^{-} \tag{2}\]  
Figure 11: Lithium ions flow from the anode to the cathode and push electrons to flow within outside circuit. The electric vehicle charges in the reverse process. Adapted from [89; 90].  
Figure 10: The trend of global lithium-ion batteries and electric vehicles in the last decade. Data from [72; 83; 87].  
The era of digitalization always considers time minimization as a primary goal. The same modern technology is focusing on new discoveries that enhance efficiency, durability, and time-saving. By considering such factors, LIB has more convincing advantages over other types of batteries. These advantages include a low memory effect, a high specific power of about 300 W/kg with a high specific energy of 100 Wh/kg, and a long life of 1000 cycles [38; 91]. These excellent characteristics make LIB preferred over nickel-metal hydride batteries (NiMH) as reliable energy storage technology for electric vehicles. Interestingly, the energy storage density of LIB is twice that of NiMH batteries. Apart from its high energy density [92], LIB has shown good performance in high-temperatures and is also recyclable [38].