esa-sceva/satcom-chunk-collection huggingface dataset:
# Study of In-Plane Mechanical Properties of Novel Ellipse-Based Chiral Honeycomb Structure
## 3 Parameters Analysis of E-Antitet
### Effect of Different \(\alpha_{x}\) and \(\alpha_{y}\) on Poisson's Ratio and Young's Modulus  
The ligament length also has a large effect on the Poisson's ratio and Young's modulus of the chiral honeycomb structures, so this section mainly discusses the adjustment effect of ligament length. In view of the orthogonal anisotropic character of E-antitet, it is necessary to discuss the effects of changes in \(l_{x}\) and \(l_{y}\) on the mechanical properties individually. For comparison's convenience, the dimensional relationships of the E-antitet, antitet-1 and antitet-2 basis cells can be defined as \(\alpha_{x}=\alpha_{ax}^{E-antitet}=1/2\alpha_{bx}^{E-antitet}=1/2\alpha_{xy}^{ antitet-1}=\alpha_{rx}^{antitet-2}\) as uniform variables when changing \(l_{x}\), where the superscript indicates the cell type, as follows: Figure 6a,b respectively show the effects of E-antitet, antitet-1 and antitet-2 on [PERSON]'s ratio and Young's modulus with different \(\alpha_{x}\), and the detailed results are shown in Table A3. It can be seen that, with increasing \(\alpha_{x}\), both E-antitet and antitet show a slow increase in \(v_{yx}\) and \(E_{x}\), while both \(v_{xy}\) and \(E_{y}\) show a decrease. Due to the change of \(l_{x}\) and \(l_{y}\), antitet-1 and antitet-2 also exhibit certain orthogonal anisotropy characteristics, but E-antitet can achieve a larger range of adjustment. In particular, \(E_{y}\) can be significantly improved, giving it a higher intensity in the \(y\)-direction.  
Here, we use the same definition of \(\alpha_{y}=\alpha_{ay}^{E-antitet}=1/2\alpha_{by}^{E-antitet}=1/2\alpha_{xy}^{ antitet-1}=\alpha_{ry}^{antitet-2}\). Figure 7a,b respectively show the effect of different \(\alpha_{y}\) on the Poisson's ratio and [PERSON]'s modulus for E-antitet, antitet-1 and antitet-2, and their detailed results are shown in Table A4. It can be seen that \(v_{xy}\) and \(v_{yx}\) of E-antitet, antitet-1 and antitet-2 increase and decrease, respectively, when \(\alpha_{y}\) increases, which means opposite to the trend of \(\alpha_{x}\). For [PERSON]'s modulus, antitet-1 and antitet-2 also show the opposite trend to \(\alpha_{x}\), which means that \(E_{x}\) and \(E_{y}\) decrease and increase, respectively, when \(\alpha_{y}\) increases, but [PERSON]'s modulus in both directions of E-antitet shows a decreasing trend. It is worth noting that the error in the theoretical derivations and FEM simulations of the Young's modulus \(E_{y}\) of E-antitet is larger when \(\alpha_{y}=2.60\), which means the shorter ligament length \(l_{y}\) in the \(y\)-direction results in a shorter effective ligament length \(l_{xy}\) when the classical beam assumptions in the theoretical derivations are no longer applicable, and thus, a larger error occurs.  
Figure 6: Trends of [PERSON]’s ratio and Young’s modulus of E-antitet at different \(\alpha_{x}\): Comparison of the results of analytical and numercal solutions of E-antitet with antitet-1 and antitet-2. (**a**) [PERSON]’s ratio and (**b**) [PERSON]’s modulus.
## 4 Results from the Literature Review
### Smart Lighting Systems  
Proper lighting is essential for visibility, which greatly enhances travel comfort and road safety. However, streetlight operation requires substantial energy, incurring significant costs and environmental impacts. Consequently, extensive research is directed toward improving the efficiency of lighting systems [148]. Advances in both wired and wireless networks, control technologies, and embedded systems now allow for modern lighting solutions that minimize energy consumption. Smart lighting systems, which can automatically adjust light intensity in real time based on current needs (e.g., traffic volume, time of day, and weather conditions), are increasingly regarded as key tools for reducing energy waste and, in a broader perspective, for limiting greenhouse gas emissions [149]. Moreover, IoT-enabled smart lighting systems, supported by advanced control units, can lower electricity costs--a particularly valuable benefit when financial resources are constrained [150; 151]. Research also highlights that these systems allow for optimal lighting of critical zones, such as bus stops, transit stations, and pedestrian crossings, facilitating crowd management, reducing accident risk, and enhancing overall urban safety, especially at night [152].
# The Extended SLM Combined Autoencoder of the PAPR Reduction Scheme in DCO-OFDM Systems
## 3 Results and Discussion
The time complexity of original SLM is \(O(N^{3})\), while the time complexity of ESLM-AE is \(O(N^{2})\), the same as the clipping method.
# Cooperative Communication Based Protocols for Underwater Wireless Sensors Networks: A Review
## 6 Challenges and Future Trends in Cooperative UWSNs
### Designing Cooperative UWSNs for Real-World Applications  
As often happens in engineering, the gains achieved with any novel solution are offset by certain losses or increased costs. In the case of cooperative and multi-hop architectures, the system becomes more complex. Such complexity arises from the need for sophisticated algorithms to manage cooperative strategies and the requirement for precise network synchronization to ensure that data is transmitted and received correctly across multiple hops.  
To summarize, the cost is identified by the overall increased complexity of the system, including the need for more advanced hardware and software solutions to handle cooperation and synchronization, and the need for more rigorous maintenance protocols. However, these costs can be justified in real-world underwater applications where traditional single-path communication methods fail to provide reliable and efficient connectivity. For instance, in underwater environmental monitoring, sensor networks can significantly benefit from cooperative communication. By using multiple nodes to relay data, the network can cover larger areas and provide more reliable data transmission, even in the presence of obstacles or varying water conditions. Similarly, in underwater robotics systems used for exploration or maintenance of underwater infrastructures, cooperative communication can ensure that data from various robots is aggregated efficiently and transmitted to the control center, enhancing the overall mission's success. In underwater rescue operations, where timely and reliable communication is crucial, multi-hop architectures can provide the necessary connectivity between divers, remotely operated vehicles (ROVs), and surface vessels. This ensures that critical information is relayed quickly and accurately, potentially saving lives and resources.  
In conclusion, while the implementation of cooperative and multi-hop communications in underwater environments introduces additional complexity and costs, the significant improvements in performance and reliability make it a valuable approach for many real-world applications. The enhanced communication capabilities can lead to more effective monitoring, exploration, maintenance, and rescue operations, thereby overcoming the inherent challenges of UWAC.
## 3 Results
### Case Description of a Historical Building  
A typical historical canal house model is investigated in this subsection, respecting the building's historical appeal (Figure 2a). Custom-made BIPV modules of monocrystalline silicon with typical wall bricks dimensions (210 mm \(\times\) 100 mm \(\times\) 50 mm) and colour were proposed (Figure 2b) [56]. Similarly, BIPV roof tiles were used to provide a non-intrusive appearance (Figure 1c) [57].  
As the chosen BIPV modules could be considered aesthetically non-intrusive, the modules were mainly placed based on average irradiance assessment. The monocrystalline silicon cells provide 150 W\({}_{\text{P}}\)/m\({}^{2}\) depending on the colours [56]. Figure 3 shows the average irradiance and transparent BIPV windows applied in the south facade. The western side is also used due to the absence of any obstacles. To ensure that the building becomes an energy-plus building, 15 kWp is installed as the limit of net metering in the Netherlands [58], resulting in 8 MWh annually. The installations, including transparent windows, are shown in Figure 3. The load profile of an average Dutch family with three children was used and upscaled to 6 MWh, considering the house's size. Hourly based average Dutch load profiles were used [30]. Although the self-consumption was 33%, the building achieved high self-sufficiency (136%). The electricity tariff for import and feed-in was 23 cents/kWh [50] and CAPEX 22 kEUR, respectively. This resulted in an energy-plus building with a payback time of 16 years.  
Although a residential building, this example might belong to a protected historic neighbourhood and therefore some of its design features need to be highlighted. The first feature is the geometry and layout of the front facade that is entirely preserved. The second feature is glazing of the front facade windows that could be affected by the proposed PV integration. In this context, it is important to find a transparent PV glazing solution that would be entirely non-intrusive, preferably invisible.  
As with the front facade, the geometry of the building is not affected by the integration of the PV system on the roof. Since the building roof parts equipped with the PV system are hardly visible from the street, and since the BIPV roof tiles have been selected, the architectural design features have not been intruded upon.  
Figure 2: Amsterdam canal house (**a**), the subject is the highest building (middle), the brick-form BIPV panels (**b**) and tiles representative of the roof tiles (**c**). The curved structure of conventional tiles is ignored for the computational purposes.  
From an architectural point of view, the most critical factor is the integration of PV brick-form BIPV tiles that affect the original specific materialization of the building and are visible in the neighbourhood context. This BIPV solution might be expected to become an issue for discussion with the institutions that protect historical buildings.
# A Review of Multifunctional Antenna Designs for Internet of Things
## 2 Materials and Methods
### Smart Cities
#### 2.3.2 State-of-the-Art Compact Antennas
This design uniquely incorporates \(\Gamma\)-dipoles arranged and rotated in such a way that the array mirrors the polarization agility of a crossed-dipole in each corner, enabling it to adapt to a wide range of polarization requirements. The clever positioning and orientation of the \(\Gamma\)-dipoles provide the array with a remarkable beamforming versatility. When operating near the broadside orientation (normal to the array's surface), and with appropriate phasing, the array mimics the behavior of a uniform planar array. This configuration facilitates conventional beamforming techniques. Conversely, when operating near the end-fire orientation (parallel to the array's surface), the array's behavior transitions to that of a uniform circular array. This shift not only showcases the array's flexible beamforming capabilities but also highlights its adaptability to different operational modes based on orientation. One of the most striking features of this antenna array is its physical flexibility. The array can be curved or  
Figure 18: An electronically steerable parasitic array radiator (ESPAR) antenna, where the variable load is implemented with an electronically activated capacitive load loop [107]. even distorted to conform to the surface of the package of an IoT device it serves, while maintaining nearly identical operational behavior but losing some of its beamforming capabilities. However, for future work an appropriate feeding network must be developed to fully harness the benefits of the proposed antenna. An attempt to further minimize the antenna's footprint was investigated in [110] where a multi-sectoral annular antenna with electrical length \(0.018\lambda_{0}\) was designed, as depicted in Figure 20a. This antenna employs slits and vias as methods for enhancing mutual coupling, resulting in a simplified configuration. By feeding the antenna's sectors through different ports, the design supports digital beamforming techniques, allowing for dynamic adjustment of the antenna's directional pattern. One of the standout features of this antenna is its ability to produce various polarization states with different radiation patterns (Figure 20c), including both LP and CP. Despite its innovative design and impressive efficiency and gain--up to 78% and 4.62 dBi, respectively--the antenna faces challenges in terms of its impedance bandwidth and return loss. These limitations suggest areas for further research and development, as overcoming these obstacles could significantly enhance the antenna's applicability and performance in real-world scenarios. A challenging feature of this non-uniform array is the implementation of its controllable feeding network. This has not been presented yet but it is expected to be feasible based on a low-cost software-defined radio or even a dedicated chip.
# Impact of Industrial Application of Fast Carbonation of Recycled Concrete Aggregates
## 2 Pilot Installations
### Carbonation in a Fluidized Bed at the LafargeHolicim Val d'Azergues Cement Plant  
The demonstrator installed at the LafargeHolicim plant in Val d'Azergues (Figure 5) was also described in a previous paper [10]. It was a fluidized bed dryer adapted into a cross-flow reactor for the occasion, with the cement plant gases directly treating the recycled concrete aggregates. It was directly connected to the cement plant gases by metal pipes. The plant gases (CO2 content of about 20%) were tapped into the main filter located upstream of the stack; therefore, an additional filter was placed at the reactor outlet to prevent any additional dust release at the plant stack.  
Figure 4: Rotating drum at the Vicat Créchy cement plant.  
To remedy the difficulties encountered during the first phase (high humidity in the carbonator chamber and insufficient inclination of the hearth), several improvements to the process were implemented that took advantage of the change in the main filter of the plant:  
* Reinstallation of the pilot at a location closer to the new gas tapping. At the same time, it was necessary to integrate a slope of about 3% into the carbonator to facilitate the flow of materials.
* Reconnection of the pilot to the new plant filter with jointed stainless steel pipes. The original pipes could not be reused because of the different geometry (elbows, shorter distance). This new configuration was also intended to increase the inlet temperature of the gases in the carbonator.
* Welding and better-jointed fixing of the perforated bottom to limit the preferential passages of gases on the sides of the apparatus to optimize the fluidization and the solid-gas reaction.
* Installation of continuous and controlled feeding of the material to limit discontinuity of the load in the carbonator and to support the fluidization.  
The carbonation rates were also measured utilizing loss on ignition. The measurements in both fractions are presented in Table 2. The modifications made during phase 2 significantly improved the CO\({}_{2}\) intakes. For the recycled sand, the values obtained were comparable to those determined in the laboratory at the optimal water content (49 kg of CO\({}_{2}\)/t of RCA). It appeared that the process only slightly modified the particle size distribution of the materials (Figures 3 and 4); there was no disintegration of the materials.
## 5 Evaluation Criteria for Localization  
Evaluating the performance of the localization algorithm is important for researchers, either to validate a new algorithm against the previous state of the art or choosing a localization algorithm that best fit the requirements of the corresponding application scenario. Since different applications will have different needs, it is important for the researcher to decide what performance criteria or evaluation metrics the localization algorithm are to be compared against other algorithms that fits different applications need. A broader set of evaluation criteria are useful both for the developers and the users of the localization algorithms in order to deeply understand the application needs. Examples of the evaluation  
It is also important for the accuracy metric to reflect not only the positional error in terms of the distance, but also in terms of the geometry of the network. If only average node position error is used, then there is a huge difference in the correctness of the relative geometry of the network estimated by the localization algorithm and the relative geometry of the actual network. This problem was identified by [108] and is addressed by defining the following metric known as global energy ratio.  
\[GER=\frac{1}{n(n-1)/2}\sqrt{\sum_{i=1}^{n}\sum_{j=i+1}^{n}\left(\frac{\hat{d}_{ ij}-d_{ij}}{d_{ij}}\right)^{2}} \tag{8}\]  
The distance error between the estimated distance (\(\hat{d}_{ij}\)) and the known distance (\(d_{ij}\)) is normalized by the known distance (\(d_{ij}\)), making the error a percentage of the known distance.  
The \(GER\) metric does not reflect the rms error [109] and is addressed by defining an accuracy metric that better reflects the rms error called global distance error (\(GDE\)).  
\[GDE=\frac{1}{R}\sqrt{\frac{\sum_{i=1}^{n}\sum_{j=i+1}^{n}\left(\frac{\hat{d}_{ ij}-d_{ij}}{d_{ij}}\right)^{2}}{n(n-1)/2}} \tag{9}\]  
where, \(R\) represents the average radio range of a sensor node. The \(GDE\) calculates the localization error represented as a percentage of the average distance nodes can communicate over.
# Research on an Index System for the Earthquake Disaster Resistance Capability of Highway Tunnels
## 2 Analysis of Seismic Damage Scenes in Highway Tunnels
### Analysis of the Influencing Factors of Earthquake Disasters in Portal Sections of Highway Tunnels  
#### 3.2.1 Tunnel-Side Slope Collapse  
Tunnel-side slope collapse is damage caused by the collapse of the side slope at the tunnel portal section under the action of an earthquake. It is also the root cause of secondary tunnel damage. In the case of the investigation, the landslide phenomenon occurred in the earthquake at the side slope of the Baiyun Tunnel portal section, and the earth-rock falling from the slope blocked the portal section. The reason is that the rock mass of the side slope is weathered hard rock, and its nature is relatively loose. The landslide and collapse occurred on both sides of the portal section of the grass slope tunnel. The lithology of the side slope is argillaceous limestone with a loose structure and steep slope, which is mainly composed of rock and soil.  
As shown in the above cases, the specific reasons leading to the collapse of the side slope are mainly loose rock (soil) mass on the side slope, the accumulation of gravel soil, the high and steep slope and the tendency of landslides. Under the action of an earthquake, the rock (soil) mass becomes unstable, collapses, slides and smashes and blocks the portal section and road. Therefore, it can be considered an engineering geological factor.
## 4 Software Defined Networking (SDN)  
In general, traditional networks are complex, and managing them is not an easy task because the control and data planes are combined in network elements (nodes). The paths are determined by the control plane and sent to the data plane. In this traditional method, when the flow management (forwarding policy) has been defined, the only way to modify the policy is via changes to the configuration of the network element. Thus, their operators must configure each individual network element (i.e., switches and routers) separately to express the desired high-level network policies. The configurations are usually done based on several low-level and vendor-specific commands [40; 41; 42].  
In addition to configuration issues of the network elements, network environments should adapt to traffic changes and endure the dynamics of faults. However, to enforce the required policies, traditional IP networks have poor automatic reconfiguration and response mechanisms [40].  
In order to solve the limitations of traditional network infrastructures, SDN was proposed. Unlike traditional IP networks in which the control and data planes are tightly coupled and embedded in the same networking elements, SDN separates the control plane from the data plane. In SDN, control is migrated out of the network elements and into the separate, centralized controller. This control and data planes separation in SDN brings some advantages: (1) it can break the vertical integration, and (2) it can simplify policy enforcement and network (re)configuration and evolution. It is because that the network elements (i.e., switches and routers) become simple forwarding devices, and there is a logically centralized controller [40; 41; 42].  
We can investigate SDN from various perspectives. Figure 4 presents a tri-fold perspective of SDNs: planes, layers and system design perspectives.  
Figure 4: SDN perspectives in planes, layers and system design architecture (inspired by [35; 40; 41]) (**a**) planes perspective, (**b**) layers perspective, (**c**) system design perspective.
## 4 Experimental Results
### Experimental Study 1
#### 4.1.2 Results Obtained Using the VGG16 Model  
The VGG16 model architecture, which by default accepts input images of size \(224\times 224\times 3\), was customized and retrained to meet the specific requirements of this study. The image input size in the VGG16 architecture was modified to 50 \(\times\) 50 \(\times\) 3. During model training, the previous layers were initialized with pre-trained weights from the ImageNet dataset, which allowed these layers to retain their learned parameters. In contrast, only the final layers were trained. Subsequently, additional layers are appended to the model by accessing its output layer. In the output layer of the model, the sigmoid activation function is employed to calculate the probabilities of two classes, with the BCE loss function preferred in the training process. The model was trained with the following parameters: Adam optimization algorithm, 0.001 learning rate, 50 epochs, and 200 batch size. These settings enabled the model to classify correctly by effectively optimizing the loss function. The model achieved 92.99% accuracy, 81.78% precision, 68.97% recall, and an F1 score of 74.83%. In addition, the model achieved an accuracy of 93.03% on the validation dataset. Figure 6 presents the accuracy and loss graph of the VGG16 model developed within the framework of experimental study 1.
# A Fine Fast Acquisition Scheme for a Communication and Navigation Fusion System
## 3 Fast Acquisition Method  
Based on the analysis above, the reduction of acquisition time requires the reduction of search space and the improvement of detection performance. Therefore, a fast double dwell acquisition method based on SSR and DD-MAX/TC-CACFAR method is proposed here to realize fast acquisition in CNFS positioning receiver.