esa-sceva/satcom-chunk-collection huggingface dataset:
# Dual-Band Monopole Antenna for RFID Applications
## 2 Antenna Design and Configuration  
Configuration of the antenna is illustrated in Figure 1. It is printed on a low-cost FR-4 dielectric, whose relative permittivity, loss tangent, and thickness are 4.4, 0.025, and h\({}_{\text{sub}}\) = 1.6 mm, respectively. The FR4 dielectric combines good electrical features, price, and availability. Compared with other materials, FR4 material is sufficiently cheap and available in the market and has been widely used in antenna designing for frequencies less than 6 GHz. Moreover, FR-4 material is available in more thickness values than other ones, which gives more design flexibility. However, as the antenna operation frequency is increased, the permittivity of FR-4 varies and loss in the substrate increases [16]. Therefore, for ultra-high frequency designs, it is better to use materials prone to loss, such as Arlon, Roger, and others.  
Figure 1: (**a**) Side, (**b**) top, and (**c**) bottom views of the antenna.  
The radiation patch of the designed antenna is connected to a rectangular feed-line with \(\mathrm{W_{f}}\) width and \(\mathrm{L_{f}}\) length. The width of the microstrip feed-line is fixed at 3 mm. On the other side of the substrate, a conducting ground plane of \(\mathrm{W_{sub}}\) width and \(\mathrm{L_{gnd}}\) length is placed. The antenna is connected to a 50 \(\mathrm{\SIUnitSymbolOhm}\) SMA connector for signal transmission. The parameter values for the antenna design are listed in Table 1.
## 2 Methodology
### Orbital Configuration and Sensor Type
#### 2.2.1 Passive Microwave Radiometer  
The first evaluated sensor is an AMSR2-like PMW radiometer [45]. It has a wide swath and relatively high revisit frequency but typically has a coarse spatial resolution (\(\sim\)10 km). PMW radiometers have served as stalwarts for snow mass estimation over the last 30+ years [12] and have demonstrated considerable skill as estimating relatively dry, shallow snow mass in relatively flat terrain and in the absence of dense vegetation [10].
# Building Realistic Mobility Models for Mobile Ad Hoc Networks
## 5 Battlefield Simulation Model
### Battlefield Model Usage and Verification  
The battlefield model developed in this research has been verified at two stages. Timemaps is a visual tool, and so, the initial model within Timemaps has been checked visually (and manually) to confirm that all the nodes are following the required paths and timing (see Figures 4-6). These movements were also checked in the real building (without the mouse holes), using a group of volunteer students to ensure that the timings were feasible. Once the Timemaps XML data has been converted into ns-2 mobility file format, the simulation is initially run without communication. Trace data is output to the network animation tool (NAM) that comes with ns-2 (ns-2, nd; [186] see Figure 8). This allows the movement patterns and timings used by ns-2, as well as the format conversion, to be verified visually. These checks confirm that the model used in the ns-2 simulations accurately reflects the military tactics employed in this scenario, including speeds of node movement, paths followed, and distribution of nodes throughout the simulation. It also confirms that the overall time taken for the simulation is appropriate for a military operation of this type, when compared with the previously mentioned example of the Iranian Embassy siege ([PERSON], 2002, [184]). Figure 8 shows the position of all the nodes at the end of the operation, as displayed by NAM. NAM does not allow for overlay maps or colour, but the movement of the nodes can be followed on screen and is seen to match the movements in the Timemaps animation. A comparison of Figures 6 and 8 shows the nodes in the same relative locations at the end of the sequence and thereby, confirms that the Timemaps model has been correctly translated into an ns-2 movement file.
## 2 Materials and Methods
### Methodology
#### 2.2.1 Unmanned Aerial Vehicle (UAV) Data  
The UAV data used in this experiment was the imagery captured using the MicaSense RedEdge imaging sensor, embedded on a fixed wing of the DJI Matrice 600 (M600) UAV system supplied by the Da-Jiang Innovations, Shenzhen, China. This multispectral imaging sensor scanned the road pavement at 8.55 cm spatial resolution at 47.2\({}^{\circ}\) horizontal field of view (HFOV). The MicaSense RedEdge sensor captured the road pavement using five narrow spectral channels, i.e., blue (475 nm), green (560 nm), red (668 nm), near-infrared (840 nm) and red-edge (717 nm) wavelengths of the electromagnetic spectrum. Table 1 provides a detailed description of the UAV system employed to acquire the imagery used in this study. The advantage of employing this narrow-band camera was based on its ability to take precise measurements of certain wavelengths, resulting in more detailed and accurate land surface information. A single UAV image with five (5) spectral channels was subsequently acquired to capture asphalt surface containing potholes. Detailed information regarding the imagery used is provided in Table 1.  
Figure 2: Schematic flowchart diagram explaining the employed approach.
###### Abstract  
Study on viscoelastic properties of the multi-layered coarse-grained soil (CGS) is very important for safety assessment and disaster prevention of subgrade engineering. Current research work is mainly focused on the one-layered CGS and the actual pebble inclusion of irregular polyhedron is usually simplified as an ideal shape of sphere or ellipsoid. Very few studies are available for predicting viscoelastic parameters of the multi-layered CGS. In this paper, a new method is proposed to predict viscoelastic parameters of multi-layered CGS based on the homogenization method and elastic-viscoelastic corresponding principle, in which the interface-layer viscoelasticity and the actual shape of pebble inclusion are firstly taken into account. Research results show the creep deformation is decreased with the increase of the shape factor (\(\rho\)) of pebble inclusion, and the interface-layer height (\(h\)) and numbers (N). \(\rho\) is in the range of 1-1.8 and the suitable interface-layer height is 20-30% as much as the height of one-layered CGS. The tested creep curves of the multi-layered CGS agree well with the predicted ones and can prove the existence of the interface-layer (considering at least one interface-layer) and verify the validity of this new interface-layer method.  
Keywords: viscoelastic parameter prediction; multi-layered coarse-grained soil; interface-layer; shape factor of pebble inclusion; creep test +
Footnote †: journal: Applied Sciences
# The Role of Mobile Application Acceptance in Shaping E-Customer Service
## 4 Results
### Qualitative Results
#### 4.2.3. Ways Mobile App Acceptance Is Shaping Customer Service  
Participants 2, 3, and 5 stated that mobile app acceptance is increasing customer interactions with retailers. For instance, customers quickly access sales representatives using the mobile app, which addresses their issues within a short period. Customers' complaints are effectively addressed through mobile applications, which eventually contribute to improved customer experience.  
Participant 5: _\"Online retailers have improved service delivery to customers such as faster response to inquiries and quick order placement.\"_  
The increased acceptance of mobile applications has been harnessed by online retailers to automate business operations, such as digital placement of product or service orders, customer inquiry, and customer check-ins. Quick service delivery has contributed to increased customer satisfaction and perceived improvement in the quality of services among consumers. More time spent interacting with customers improves consumer-employee relationships by training workers to align with unique behavioral attributes of customers and efficiently manage their weaknesses.  
The increased mobile application acceptance has enhanced customer service delivery by empowering customers to solve service delivery challenges through self-service menus and help sections in mobile apps. Furthermore, organizations have linked their mobile business applications with contact or support centers for resolving issues that customers cannot resolve by themselves. In this manner, increased acceptance of mobile applications acts as a driving factor towards online-based resolution of consumers' problems, which is efficient, timely, and cost-effective to clients. Through increased acceptance of mobile apps, organizations have been able to provide round-the-clock customer services irrespective of the physical location of customers. As a result, the quality of delivered services has improved due to reduced lead times and service congestions. As new customers accept mobile applications to conduct business transactions, they share their experiences with family and peers, thereby increasing the awareness and popularity of digital consumer services.
# Applications of Wireless Sensor Networks: An Up-to-Date Survey
## 2 Main WSN Applications
### Health Applications
#### 2.2.3 Hospital Patient Monitoring (or Hospitalization)  
Within healthcare facilities, such as a hospital, WSNs systems can be integrated to provide real time patient monitoring and emergency alerting for a more precise and quick response. A typical example of an application of this kind is presented in [17]. Specifically, the authors described a WSN application where wireless sensors are placed within the emergency rooms of John Hopkins hospital to monitor in real time the blood oxygen and heart rate of the patients. The researchers collected the performance statistics of the network and despite the difficulty of the hospital environment due to interference and radio noise, the application of WSNs can improve the operation of a healthcare facility. The device developed is depicted in Figure 9.
# Characteristics of Removal of Lead, Cadmium and Chromium from Soil Using Biosorbent and Biochar
###### Abstract  
The study proposed the use of aspen wood sawdust and biochar derived from this sawdust for the removal of Pb(II), Cd(II), and Cr(VI) ions from soil in systems containing single metals as well as a mixture of all the studied metals. The effectiveness of the applied sorbents was compared with the sorptive properties of activated carbon. The results showed that all the tested materials reduced the metal content in the soil, and the obtained biochar was able to sorb lead, cadmium, and chromium ions in both studied systems. The influence of the type of sorbent, its dose, process duration, and the impact of metal on the removal efficiency and sorption capacity was analyzed. A statistical analysis of the obtained results was also conducted, determining the influence of process parameters on the removal capabilities of metal ions. The highest Pb, Cd and Cr ion removal efficiencies were obtained in a 36-day process at a sorbent dose of 10%. Aspen sawdust, biochar and activated carbon removed 46%, 50% and 71% of Pb(II), 35%, 43% and 53% of Cd(II) and 15%, 27% and 38% of Cr(VI), respectively. In turn, the highest sorption capacity values were achieved in a 36-day process at a sorbent dose of 2%, obtaining results of 20.2 mg/g, 22.3 mg/g and 23.2 mg/g of Pb(II), 5.1 mg/g, 7.9 mg/g and 11.7 mg/g of Cd(II) and 3.8 mg/g, 5.8 mg/g and 8.5 mg/g of Cr(VI), respectively. It was found that both raw aspen wood sawdust and biochar derived from this wood are effective in removing toxic metal ions from soil, which presents a potential solution to their presence in the natural environment.  
heavy metal; adsorption; biosorption; pyrolysis; aspen wood
## 2 Methods
### The Basic Algorithmic Approaches
The essence of the VNS [42] is that for some intermediate solution, we determine a set of neighborhoods of this solution. From this set, the next type of neighborhood is selected, and we apply the corresponding local search algorithm for searching in this solution. If this algorithm finds an improved solution, the intermediate solution is replaced by this new solution, and the search continues in the same neighborhood. If the next local search algorithm cannot improve the solution, a new search neighborhood is selected from the set of neighborhoods. The stop criterion is the time limitation. Several algorithms use only two types of neighborhoods: the first is \(\varepsilon\)-neighborhood (i.e., at this step, the problem of continuous optimization is solved). For example, the search in SWAP neighborhood is a popular method for solving p-median and k-means problems. The j-means [93] algorithm using these neighborhoods is one of the most accurate methods for solving such problems. The essence of the search in SWAP neighborhoods is as follows. Let \(S=\{X_{1},\,\ldots,\,X_{p}\}\) be the local optimum of the p-median problem in \(\varepsilon\)-neighborhood (such a solution can be obtained by the ALA algorithm or other algorithms such as gradient descent). If the value of the objective function has improved due to this replacement, then the search continues in the \(\varepsilon\)-neighborhood of the new obtained solution (the problem of continuous optimization is solved again). The search algorithm makes an attempt to replace some of the medians \(X_{1},\,\ldots,\,X_{p}\) with one of the data vectors \(A_{1},\,\ldots\,A_{N}\). Search in the SWAP neighborhoods can be regular (all possible replacements are enumerated) or randomized (the medians and demand points are randomly picked for the replacement). Let us denote by SWAP\({}_{r}\) a neighborhood (set of solutions) of a current solution obtained by the replacement of \(r\) medians by demand points. In our computational experiments (described in detail in Section 3) on various problems from repositories [94; 95], we investigated the dependence of the efficiency (ability to reach the minimum values of the objective functions) of the search in SWAP\({}_{r}\) neighborhood on the parameter \(r\). The results obtained after the fixed runtime are given in Figure 1. Obviously, these results are highly dependent on \(r\).
# Use of Foamed Cement Banking for Reducing Expressways Embankment Settlement
## 3 Field Study on Shen-Jia-Hu Highway  
### Engineering Situation  
The practical site for experiments was part of the Zhejiang Shenjiahua Hangzhou Expressway (Lianhang Section) project (hereafter referred to as the Shen-Jia-Hu expressway), which is located on Hang-jia-hu plain, the geographical location of Shen-Jia-Hu is shown in Figure 2. This region has a developed economy, high population density, and high transportation requirements. However, the numerous lakes and rivers cause a large amount of soft soil in this region. Most of its road sections pass through soft soil foundation, which contain soils characterized by high moisture content, high compression, low strength, and low permeability, which will cause greater road settlement.  
In view of the engineering geological conditions, in addition to conventional improvement methods such as grout spray pile (pile diameter 500.0 mm, 3.05 million linear meters) and prestressed concrete pipe pile (pile diameter 400.0 mm, wall thickness 60.0 mm, 590 thousand linear meters), Shen-Jia-Hu expressway also adopted equal preloading (2.39 million m\({}^{3}\)) along the whole line. The expressway subgrade was filled with earthworks mixture. The foundation improvement mainly adopted stacking load pre-compaction and combined the plastic wick drain. The road section chosen for experiments is the EK0 + 323 ramp bridge road, which has a 10 m wide pavement, a 3.25 m high embank ment, and a 1:1.5 slope grade. The soil cohesion and internal friction angle were obtained through direct shear experiment, and the soil water content was obtained through the oven-drying method. The other parameters and specific steps were determined according to the Standard for geotechnical testing method [3], and the parameters are given in Table 2. It should be noted that the soil parameters were obtained after the surcharge preloading method. The cohesion values were relatively higher than other soil.
# Analysis of a Nature-Inspired Shape for a Vertical Axis Wind Turbine
## 2 Materials and Methods
### Numerical Model
It was verified that these dimensions are large enough to avoid any border effect. This was checked repeating the simulation using domains \(10\;\times\;10\;\times\;25\;\mathrm{m}\) and \(12\;\times\;12\;\times\;30\;\mathrm{m}\) and obtaining the same results. The boundary conditions are also shown in this figure. The upstream face was modeled as a velocity inlet, while the downstream face was modeled as an outlet. The exterior faces were modeled as free slip in order to minimize border effects. This boundary condition imposes a zero shear stress, i.e., the tangential velocity derivative normal to the boundary is zero. The turbine blades were treated as no-slip surfaces. The mesh is shown in Figure 6. This figure shows a tri-dimensional view and a detail of the middle plane. The mesh consists of tetrahedral elements from 0.05 to 0.2 m size. The size is finer around the turbine. Two zones were established: static and rotating. The rotating domain is a cylinder around the turbine which rotates around the turbine axis. The static domain is the remaining region, which remains fixed. A sliding interface connects the static and rotating domains. Figure 5: Boundary conditions. Several meshes with different elements were tested in order to verify that the results are independent of the mesh size. Table 1 indicates the power coefficient obtained at TSR = 1 using four meshes. It can be seen that meshes 3 and 4 provide the same result. According to this, mesh 3 was selected. Regarding the near wall cells, a boundary layer with five layers was established, providing a y+ lower than 1.
# Comparison of Basic Notch Filters for Semiconductor Optical Amplifier Pattern Effect Mitigation
## 6 ODI vs. MRR Qualitative Comparison
### Tunability:
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Characteristic** & **MRR** & **ODI** \\ \hline Width & Coarse & Dense \\ \hline Adjustment & Rather fine (radius) & Fine (path length imbalance) or \\  & & bulky (optical delay line) \\ \hline Multi-wavelength Operation & Yes & Yes \\ \multirow{4}{*}{Free Spectral Range (FSR)} & Difficult for DWDM since it & \\  & & requires cascading; is & \\  & & compromised by increased & \\  & & footprint and complexity & \\  & & \\  & & Yes, easy with single MRR & \\  & & owing to high and controllable & Yes, difficult due to low and \\  & & finesse & fixed finesse \\ \multirow{4}{*}{Detuning} & \multirow{4}{*}{(iii) handling of variations in channel positions} & Yes, straightforward owing to & \\  & & sharp spectral selectivity & \\  & & & \\ \cline{2-3}  & Feasibility & Yes, thermo-optic effect with mWs/FSR \\ \cline{2-3}  & Mechanism & Relaxed (periodic round-trips & \\  & and resonant enhancement) & Tight (one-way interference) \\ \cline{2-3}  & Precision & Normal & Demanding \\ \cline{2-3}  & Tolerance & High & Medium \\ \hline Tunability & & Yes, high & Yes, medium \\ \hline \multirow{4}{*}{Peak-to-Notch Contrast Ratio (FNCR)} & Magnitude & High (>20 dB) & \\  & Operating Condition & Demanding (critical coupling) & Normal (branching couplers \\  & & splitting ratio) \\ \cline{2-3}  & \multirow{4}{*}{Adjustment} & Complicated (electrically & \\  & Contrast Ratio & driving MEMS to control gap & Simple (varying power \\  & & between bus and ring) & \\ \cline{2-3}  & \multirow{4}{*}{Tolerance} & Tight (matching of field & \\  & & transmission coefficient and & \\  & & amplitude attenuation factor & \\  & & within 3\%) & \\ \hline \multirow{4}{*}{Temperature Sensitivity} & Yes, high negative TOC material, & \multirow{4}{*}{Yes, athermal operation without} & \\  & & but still not compatibility with & \\  & & standard CMOS technology & \\ \hline \multirow{4}{*}{Integration Potential} & Compatibility with planar light & \multirow{4}{*}{Yes} & \multirow{4}{*}{Yes} \\  & wave technology & & \\ \cline{2-3}  & Co-packaging Platform & \multirow{4}{*}{Yes (hybrid)} & \multirow{4}{*}{Yes (monolithic)} \\  & with SOA & & \\ \hline \multirow{4}{*}{Device} & Size and footprint & Ultra-compact & Compact or bulk \\ \cline{2-3}  & Fabrication, (materials, & \\ \cline{2-3}  & techniques, processes) & Well-developed & Established \\ \cline{2-3}  & CMOS Compatible & Yes & Yes \\ \cline{2-3}  & Cost & Affordable (single channel amplification in SOA), & \\ \cline{2-3}  & Shared (multiple channel amplification in SOA) & \\ \cline{2-3}  & Commercial availability & Yes, increasing & Yes, widespread \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Qualitative comparison of MRR and ODI key characteristics.
## 3 Results and Discussion
### Method Development
#### 3.1.3 Effect of Ru(III) Modifier  
It is also know that some transition metals, such as ruthenium, can significantly enhance the formation of GaF by reducing the interfering formation of GaO, which usually results in further sensitivity increase [2]. In our approach, instead of Ru(III) nitrosyl nitrate [2], the solution of RuCl\({}_{3}\) in HCl was used and the mass of modifier was optimized versus the intensity of GaF signal. The results shown in Figure 3 indicate that the optimum mass of ruthenium introduced in a form of RuCl\({}_{3}\) in 20% HCl is around 1 \(\upmu\)g. Thus with the applied time/temperature program for graphite furnace, the amount of 3 \(\upmu\)g of Ru recommended in literature [2; 34] is not necessary for the best sensitivity.
## 2 Importance of This Research  
All conventional surveying, whether using a global positioning system (GPS), a total station, or other surveying equipment, requires a great deal of time, effort, and labor. Sometimes the sites where engineering work is performed are harsh and hazardous environments where it is difficult for humans to freely move. To reduce the time, labor, and manpower required for conventional survey work, photogrammetry has been used to sur vey land areas and locations of engineering projects. The latest findings of researchers and professionals in this field have been related to the use of unmanned aerial vehicles (UAVs) to produce survey maps, digital elevation models (DEMs), orthophotos, and 3D models.  
The creation of maps using drones, like other surveying work, differs in its positional accuracy. Therefore, this research was very important because it dealt with the testing, evaluation, and analysis of the positional accuracy of geospatial data products using drones. In this study, positional accuracies without ground control points (direct georeferencing) and with ground control points (indirect georeferencing) were tested using different combinations of image sets acquired with different camera orientations and flight directions.  
In reviewing previous studies that have addressed the evaluation and analysis of positional accuracy, it was found that positional accuracy varies from one study to another, as it is influenced by many different factors. It was also noted that the topic of positional accuracy, especially in the vertical, is still in need of renewed study and research, and this was one of the motivations for this study. In this study, UAV photogrammetry products were tested to determine if they are accurate enough to replace current GNSS and total station surveying methods in engineering, cadastral, and topographic surveying [11].