esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Results and Discussion
### Power Delay Profile  
The time-varying instantaneous power delay profiles (PDPs) can characterize the impact of time variations on the received signal power. It shows the relevance of time, delay and received power. According to the wireless communication theories [26], the instantaneous PDPs can be obtained by the square of the time-varying channel impulse response \(h(t,\tau)\), shown in Equation (1).  
\[P(t,\tau)=\sum_{t}|h(t,\tau)|^{2} \tag{1}\]  
where \(P(t,\tau)\) represents the time-varying instantaneous power delay profiles and \(h(t,\tau)\) is the channel impulse response.  
Then, the average PDP can be obtained by the average operator.  
\[P_{a}(\tau)=E\{P(t,\tau)\} \tag{2}\]  
where \(P_{a}\) represents the average power delay profile, \(\tau\) is the delay, \(P\) is the power delay profile and \(E\) is the average operator.  
We obtained the instantaneous PDPs of the S2I and S2S measurements after the data pre-processing, shown in Figure 2a,b. We can find that, for the wireless channel over the sea, the received power decreases with the increase of distance. Since the measurement has been conducted over the sea, which is an open propagation environment, the wireless signal transmits mainly through the line-of-sight (LOS) path compared with the terrestrial communications, such as vehicular communication [27] and high-speed railway communication [24; 25; 28]. Furthermore, we note that the reflection path and other characteristics that need attention appear in some specific areas as well. In the S2I and S2S measurements, areas I-III and i-iii are marked in the PDP results, as shown in Figure 2. Areas I, i and iii are selected due to the strong received power with the short communication distance, while areas II, III and ii are with reflection paths caused by the surroundings or other factors.  
Figure 2: Power delay profiles for the two measurements. (**a**) is for S2I and (**b**) is for S2S.  
To analyze the wireless channel characteristic from the view of the received power and multi-path effect. The average PDPs are extracted from the selected areas I-III for S2I and areas i-iii for S2S measurements, shown in Figure 3. We choose the data within 1 sec to calculate the average PDP from the selected areas, respectively. In the S2I measurement, the Rx gradually moved away from the boat that docked at the pontoon. We can find that the delay of the LOS path is increasing with a decreasing received power, where the average power received by the LOS component is \(-20.81\) dB, \(-46.49\) dB, \(-56.65\) dB for cases I, II, III, respectively, as shown in Table 2. From the results of the average PDP, it can also be noted that the noise is more obvious when the distance between Rx and Tx is small. The shaking of the measurement boat may cause this due to the wave.
# Improving Passive Time Reversal Underwater Acoustic Communications Using Subarray Processing
## 3 Receiver Algorithms
### Tr-Dfe  
As shown in Figure 2, the estimated channels are time reversed and conjugated, convolved with the distorted signals, and summed across branches to generate a single-channel signal with slight ISI. The spatial/temporal compressions of the TR processing reduce ISI and increase SNR. TR alone usually cannot achieve perfect equalization with a limited number of hydrophones. To compensate for residual ISI, the original TR structure is followed by a single-channel equalizer (TR-DFE). Figure 2 depicts a conventional TR-DFE system with one transmitter and one \(M\) receiver. TR-DFE may be viewed as a low-complexity MC-DFE as in [2]. Like MC-DFE, TR-DFE also has performed successfully in different UWA channels. In Figure 2a, \(r(t)\) denotes the combination signal after TR processing:  
\[r(t)=\sum_{m=1}^{M}y_{m}(t)\otimes\hat{h}_{m}^{*}(-t), \tag{6}\]  
where \(\otimes\) stands for linear convolution and  
\[y_{m}(t)=s(t)\otimes h_{m}(t)+w_{m}(t). \tag{7}\]  
Then, the receive signal can be rewritten as follows:  
\[r(t)=\hat{q}(t)\otimes s(t)+\widehat{w}(t), \tag{8}\]  
where  
\[\hat{q}(t)=\sum_{m=1}^{M}h_{m}(t)\otimes\hat{h}_{m}^{*}(-t), \tag{9}\]  
and  
\[\widehat{w}(t)=\sum_{m=1}^{M}\hat{h}_{m}^{*}(-t)\otimes w(t). \tag{10}\]  
\(\hat{q}(t)\) is the estimated autocorrelation of the impulse response functions summed over the channels, and \(\widehat{w}(t)\) is the filtered noise. When M is large enough, \(\hat{q}(t)\) is close to \(\delta(t)\). The output of TR processing \(r(t)\) is equalized by the following single-channel DFE to remove residual ISI.
# Integrated Digital-Twin-Based Decision Support System for
## 4 Developing a DT Platform
### Service Layer  
The service layer leverages the outputs from the digital layer to provide actionable insights and solutions [60]. For RMB management, this layer visualizes the current status of RMB projects and addresses challenges related to reusing and allocating modules for new projects. One of its key features is spatial-temporal visualization, which dynamically integrates spatial and temporal data to represent the past, present, and future states of modular units. For example, GPS sensors provide real-time tracking information on whether a module is in the factory, in transit, on-site, or assembled. This capability allows project managers to make timely decisions regarding module allocation and logistics.  
The DT platform also supports module selection and allocation for future projects. By analyzing factors such as the module condition, proximity to the new project site, and compatibility with design requirements, the platform generates optimized allocation plans. Facility managers can input project-specific details--such as required module types, the site location, and the schedule--and receive recommendations for reusable modules, along with optimal transportation routes. This process minimizes costs and time while ensuring efficient resource utilization. Additionally, the system's integration of GISs and IoT enables logistics optimization, considering variables such as distance and road conditions. This ensures modules are transported to their destinations economically and efficiently, reducing the environmental and financial costs associated with RMB relocation.
## 3 Algorithmic Errors
### AI-Enhanced Navigation Systems
#### 3.5.6 Case Study  
Case Study: ABB Ability(tm) Marine Pilot Vision  
ABB's Marine Pilot Vision system represents a significant advancement in AI-driven navigation, enhancing situational awareness and overall navigation safety. The system employs a suite of sensors and sophisticated AI algorithms to construct a comprehensive 3D model of the vessel's surroundings. This high-resolution model enables advanced collision avoidance capabilities. For example, during a particularly complex maneuver in a congested port, the AI system provided real-time, precise guidance to the crew. This assistance helped the crew avoid potential collisions with other ships and port infrastructure, showcasing the system's ability to enhance navigational precision and safety in challenging environments. The successful implementation of this system across several vessels highlights its reliability and effectiveness [75].  
AI-enhanced navigation systems facilitate maritime safety and efficiency. By leveraging advanced algorithms and real-time data, these systems optimize routes, detect and avoid collisions, and monitor environmental conditions, ensuring safer and more efficient maritime operations.
# Photovoltaics and Electrification in Agriculture
## 2 Special Issue Overview: General Topics  
### The Use of Photovoltaics in Greenhouses  
The new context of climate change, in turn, generates new forms of production where the environmental parameters in which it takes place must be controlled more and better. The paradigm of this type of system is greenhouse cultivation. In this type of cultivation, not only the interior temperature is controlled, or parameters such as relative humidity, the amount of CO\({}_{2}\) and the nutrients applied in the case of hydroponic cultivation but also the amount of radiation that reaches the plants. In countries with high insolation, shading is used either by means of meshes or by \"limiting\" the roof. Photovoltaic solar energy as an energy source in greenhouses can also be used as a shading element for certain crops. However, the analysis of the impact of the solar panels on the crop is a topic being studied nowadays and a topic of great interest for the future development of solar energy applied to greenhouses.  
The use of alternative systems, such as semi-transparent photovoltaic panels, can add value to greenhouse cultivation. This type of panel lets a part of the radiation pass through, as it does not include a reflective layer on the back. Consequently, the panel may lose a small percentage of efficiency, which is offset by the benefits to the crop. In the work of [PERSON] et al. [3], the influence of radiation loss on production and crop quality is analyzed. In their conclusions, the shaded crop adapted to the new conditions, partially compensating for the decrease of radiation.  
The application of agrovoltaic technology in arid areas, such as the southwestern United States, using organic solar panels, was carried out by [PERSON] et al. [4] in a study exploring the influence of certain photovoltaic materials that do not completely block so-called photo active radiation (PAR), applied to hydroponic cultivation under greenhouse, something that makes it a very interesting case and with a great future for its high efficiency not only in terms of energy but also in the application of water and nutrients. Their conclusions show that, as in other cases of similar studies, the crop adapts to the decrease in radiation so that finally, the amount of harvest by weight is similar.  
In greenhouse cultivation, fixed-plane surfaces are available with a certain orientation. The estimation of radiation on such plane, depending on the location, must be carefully analyzed to determine the impact and viability on the crop and on the photovoltaic production itself, something that has been considered in the work of [PERSON] et al. [5], applying new methodology, including anisotropic models of the sky. The model is able to calculate the incidence angle of the radiation at any time besides the irradiation of a considered placement, with increased accuracy. As one of the conclusions, it allows predicting the hourly radiation reaching the crop and then the expected production.
# Strategies to Combat Multidrug-Resistant and Persistent Infectious Diseases
## 3 Repurposing Treatments against MDR and Persistent Bacteria
### Anti-Psychotics  
A decade ago, [PERSON] and [PERSON] screened the antibacterial activity of some compounds that affected neurological function, identifying 68 that disrupted infection of macrophages by _Listeria monocytogenes_[62]. After further examination of the compounds, these researchers indicated that thioridazine, an antipsychotic drug used to treat schizophrenia during the last 40 years, and berpidil, a calcium channel blocker, decreased intracellular infection by _L. monocytogenes_ in a dose-dependent manner by significantly inhibiting escape from vacuoles in vitro. Treatment of host cells with thioridazine or berpidil significantly decreased the ability of _L. monocytogenes_ to escape the phagocytic vacuole, a step required to initiate intracellular replication. Although experiments were performed using the WT _L. monocytogenes_ strain 10403S, this is an elegant example of a drug repurposing strategy, as calcium channel blockers can be used in the treatment of brain injury, as well as to combat bacterial pathogens. The effects of berpidil and thioridazine on persistent and resistant bacteria should be evaluated. In addition, the antimicrobial activity of thioridazine against other bacterial species, such as _S. aureus_[63] and _M. tuberculosis_, was also reported [64]. In the first case, the researchers observed that a dose of only 0.1 mg/L thioridazine completely inhibited the growth of _S. aureus_ phagocytosed by macrophages, suggesting intracellular bactericidal activity. Nevertheless, thioridazine was withdrawn from use worldwide in 2005 because it caused severe cardiac arrhythmia in some patients (it binds to histamine receptors). However, some generic forms of this drug are still available in the US.  
In 2016, [PERSON] and colleagues described the antibacterial effects of another antipsychotic drug, trifluoperazine [65]. Although trifluoperazine MIC values were too high to be reached in plasma and the drug did not affect the growth of _Yersinia pestis_ cells or the expression/production of their type 3 secretion system (T3 SS, an important virulent factor for this bacteria), use of this antipsychotic increased the survival of _Y. pestis_-infected macrophages in vitro and the survival of infected mice in vivo. Trifluorazine was then tested in both _Salmonella enterica_ serovar Typhimurium and _Clostridium difficile_ infection murine models, where once again it significantly increased the survival of infected mice. Interestingly, although the antibacterial activity is yet to be described, a significantly higher survival rate of mice infected with _Y. pestis_, _S. enterica_, and _C. difficile_ and treated with the drug was reported. It is, therefore, possible that the bactericidal activity is intracellular, as with thioridazine, another antipsychotic drug with a similar structure.
## 1 Introduction
#### Literature Review on Mortars with Natural Fibers: Coconut, Abaca and Toquilla
Negative effects include the possible degradation of the fibers when subjected to moisture-dryness cycles [29]. Similarly, a brief review of the most recent research findings on abaca fiber reinforced mortars is shown in Table 2.  
In view of the obtained results by other researchers shown in Table 2, it can be seen that abaca fibers also allow to improve the mechanical behavior to bending in masonry mortars [37]. Additionally, the good hygroscopic properties of these fibers and their potential application to reduce shrinkage are highlighted [35; 36]. Finally, the importance of pre-treatment of natural fibers is emphasized, with the aim of increasing their durability and favoring the integration of the fiber into the mortar matrix [34]. No research has been found on the use of toquilla straw fibers in the manufacture of cement mortars, however, the potential applications of toquilla straw as a thermoplastic reinforcement for composite materials were reported [38]. Toquilla straw or _Carludovica palmata_ has been commonly used in hot and humid regions of South America for the manufacture of hats and handicrafts. Although its application in construction has not yet been widely exploited, other similar natural fibers such as wheat straw [39], kenaf straw [40], rice straw [41] or cotton straw [42] have been widely used. In general terms, these fibers have been used as structural reinforcement material in mortar and concrete, with the aim of improving the mechanical strength, toughness and deformation capacity of cement-based composite materials, as well as obtaining improved thermal properties [43]. Moreover, there are constantly new reports about the possibility of using new natural fibers, such as guaruma (Ischinosibronkoern) of Amazonian origin--natural fibers still unexplored with great potential for use in cementitious systems [44]. Many review articles, often critical ones, have examined the potential use of natural fibers to reinforce cementitious systems [45; 46; 47]. In recent years, the need to reconcile technological development in the cement industry with the preservation of the environment has led to the use of silica-rich ash residues, from the calcination of plant fibers such as corn straw, sugar cane straw or rice straw [48]. This novel application has become a promising alternative for the partial substitution of cement in the development of new eco-friendly mortars, which in turn have physical-mechanical properties that make them competitive in the market [49]. However, although the use of natural fiber has gained prominence in the area of materials engineering due to the versatility of the use of natural fibers in cementitious composites.
## 5 Conclusions  
In this paper, the vibration characteristics of the pipeline system with a particle impact damper under random excitation are investigated. The effects of parameters such as particle material, filling rate, particle size, damper structure and boundary conditions on the vibration damping performance are investigated. Due to the lower restitution coefficient, the impact damper with steel particles has a more effective vibration reduction effect compared to the damper filled with aluminum and glass particles. When the filling rate was 20%, the damping effect of the steel balls increased by 10.4% and 25.3% compared to the aluminum and glass balls, respectively. At an 80% filling rate, the damping effect of the steel balls increased by 17.2% and 22.9%. When the filling rate of the particles was about 90%, the damping capability of the pipeline system was excellent. The effect of particle size on the pipeline system varies with the filling rate. When the filling rates are 20% and 80%, the four-cavity damper has an excellent damping effect compared to the two- and six-cavity dampers. The effect of boundary conditions on the damping effect is inconsiderable. The proposed particle impact damper can achieve a superior vibration reduction effect in the broadband frequency range, which is expected to reduce pipeline vibration under random excitation, provide an efficient tool for pipeline vibration reduction design and maintenance, and have important significance and value for pipeline vibration reduction in harsh vibration environments such as ocean engineering, aerospace, etc. In the future, the combination of testing and simulation, multiple particle damping, and active control damping will also be considered.  
Conceptualization, J.W. and J.J.; methodology, J.W. and M.J.; software, M.J., S.Y., D.Z. and Z.Z.; validation, M.J., S.Y., D.Z. and Z.Z.; formal analysis, M.J. and J.J.; investigation, S.Y.; resources, M.J. and J.J.; writing--original draft preparation, [PERSON] and M.J.; writing--review and editing, [PERSON]; supervision, [PERSON]; project administration, [PERSON] and T.Y.; funding acquisition, [PERSON] All authors have read and agreed to the published version of the manuscript.  
This research was funded by Natural Science Foundation of Shandong Province (No. ZR2020 ME121).  
Not applicable.  
The data presented in this study are available from the corresponding author upon request.  
The authors declare no conflict of interest.  
Figure 19: Influence of boundary conditions on vibration reduction effect under three filling rates.
## 3 Nonlinear State-Feedback VRFT for Approximate ORM Tracking Control Using Neural Networks
_A4_: Let the process (1) and the ORM (2) be formally written as \(\mathbf{y}_{k}=\mathbf{s}(\mathbf{x}_{k}\mathbf{u}_{k-1})\) and \(\mathbf{y}_{k}^{m}=\mathbf{s}^{m}(\mathbf{x}_{k}^{m},\mathbf{r}_{k-1})\), respectively, to capture simultaneously both the input-output dependence and the input-state-output one in a compact form. These expressions also reveal the relative degree one from input to output, without loss of generality. Assume zero initial conditions for (1) and assume the map \(\mathbf{s}\) invertible with \(\mathbf{x}_{k}\), \(\mathbf{u}_{k-1}\) computable from \(\mathbf{y}_{k}\) as \(\mathbf{x}_{k}=\left(\mathbf{s}_{x}\right)^{-1}(\mathbf{y}_{k})\), \(\mathbf{u}_{k-1}=\left(\mathbf{s}_{u}\right)^{-1}(\mathbf{y}_{k})\). Further assume that \(\mathbf{s}^{m}\) is a continuously differentiable invertible map such that \(\mathbf{x}_{k}^{m},\mathbf{r}_{k-1}^{-1}\) are computable from \(\mathbf{y}_{k}^{m}\) as \(\mathbf{x}_{k}^{m}=\left(\mathbf{s}_{x}^{m}\right)^{-1}(\mathbf{y}_{k}^{m}), \mathbf{r}_{k-1}=(\mathbf{s}_{x}^{m})^{-1}(\mathbf{y}_{k}^{m})\) and assume there exists positive constants \(B_{sx}^{m}>0,B_{sr}^{m}>0\) such that \(\|\frac{\partial\mathbf{s}^{m}(\mathbf{x}_{k}^{m},\mathbf{r}_{k-1})}{\partial \mathbf{x}_{k}^{m}}\|<B_{sx}^{m},\|\frac{\partial\mathbf{s}^{m}(\mathbf{x}_{k} ^{m},\mathbf{r}_{k-1})}{\partial\mathbf{r}_{k-1}}\|<B_{sr}^{m}\). Let zero initial conditions hold for (2). These inversion assumptions are natural for state-space systems such as (1) and (2) that have equivalent input-output models according to _A4_. For example, for given output \(\mathbf{y}_{k}\) of (1), the input is uniquely determined as \(\mathbf{u}_{k-1}=\mathbf{P}^{-1}(\mathbf{y}_{k})\), after which the state can be generated by recursion from \(\mathbf{x}_{k+1}=\mathbf{f}(\mathbf{x}_{k},\mathbf{u}_{k})\) of Equation (1). This is the sense of \(\mathbf{x}_{k}=\left(\mathbf{s}_{x}\right)^{-1}(\mathbf{y}_{k})\). Moreover, let \(\mathbf{s},\left(\mathbf{s}_{x}\right)^{-1}\) be continuously differentiable and of bounded derivative to satisfy  
\[ \begin{array}{l}\|\frac{\partial\mathbf{s}\left(\mathbf{x}_{k},\mathbf{u}_{k-1 }\right)}{\partial\mathbf{x}_{k}}\|<B_{\mathrm{s}x},\|\frac{\partial\mathbf{s} \left(\mathbf{x}_{k},\mathbf{u}_{k-1}\right)}{\partial\mathbf{u}_{k-1}}\|<B_ {\mathrm{s}u},\|\frac{\partial\left(\mathbf{s}_{x}\right)^{-1}\left(\mathbf{y }_{k}\right)}{\partial\mathbf{y}_{k}}\|<B_{\mathrm{s}y},\\ 0<B_{\mathrm{s}x}B_{\mathrm{s}y}<1.\end{array}  \tag{7}\]  
_A5_: Let a finite open-loop trajectory collected from the process be \(D=\left\{\widetilde{\mathbf{u}}_{k},\widetilde{\mathbf{x}}_{k},\widetilde{ \mathbf{y}}_{k}\right\}\subset U\times X\times Y,k=\overline{0,N-1}\) where \(\widetilde{\mathbf{u}}_{k}\) is: (1) persistently exciting, for \(\widetilde{\mathbf{y}}_{k}\) to capture all process dynamics and (2) ensuring uniform exploration of the entire domain \(U\times X\times Y\). Good exploration is achievable for large enough \(N\).