esa-sceva/satcom-chunk-collection huggingface dataset:
# Highly Porous Organic Polymers for Hydrogen Fuel Storage
## 4 Characterization of Porosity in Highly Porous Organic Polymers
Then the positron will quickly slow down (at picosecond scale) and form a positronium (Ps). After diffusing and residing in a pore for a few nanoseconds, Ps will annihilate with the electron layer at the internal wall due to the overlap of Ps wave function with the above electron layer as shown in Figure 13b. The annihilation of Ps will give off another \(\upnu\) ray with the energy of 511 \(keV\) and detected by a second detector, marking the end of a positron. The time difference between these events is basically the lifetime of Ps, which is converted to the electronic signal via a time-amplitude-convertor (TAC) and recorded in a computer. The relationship between the lifetime of Ps and pore radius (r) is well described by the Tao-Eldrup equation as follows:  
\[\tau=0.5 ns\Big{(}1-\frac{R}{R+\Delta R}+sin\frac{2\pi R}{R+\Delta R}\Big{)}^{- 1},\]  
where \(\tau\) is lifetime to Ps, R is the radius of a pore, and \(\Delta\)R is an empirical value, 1.66A, representing the thickness of electron layer on the internal wall of the pore [130]. The PALS technique is able to overcome the intrinsic limitations associated with the N\({}_{2}\) adsorption method. First, Ps has same size as a hydrogen atom, with diameter of 1.06 A, and is particularly sensitive to the pores with radii from 2-10 A. This is the range of ultra micropores that theory predicts to be optimal in adsorbing H\({}_{2}\) molecules at room temperature. Second, PALS measurements can be carried out at any temperature and hence can measure the porosity of highly porous polymers at room temperature. In addition, PALS can be performed in situ with H\({}_{2}\) adsorption/desorption processes, thus providing dynamic information on H\({}_{2}\) adsorption. Finally, Ps themselves will not create any swelling effect since both the positron and electron constituting Ps are leptons, and it is the quantum effect, rather than the classical space filling effect, that is used to obtain the pore size in PALS. Other techniques have also been used to study the porosity in porous polymers. For instance, \({}^{129}\)Xe NMR spectroscopy, however, it was found Xe atoms exclusively occupy in large pores (\(>\)20 A), not the micropores of interest [131]. Small angle X-ray scattering (SAXS) in combination with the N\({}_{2}\) gas adsorption gives the internal surface area, however, this method still relies on the N\({}_{2}\) adsorption isotherms with the limitations given above [83]. In summary, the technique best suited for characterizing ultra microporosity in highly porous organic polymers particularly for H\({}_{2}\) gas storage is positron annihilation lifetime spectroscopy (PALS). However, PALS uses radioactive material, \({}^{22}\)Na, which might limit its application even though its reactivity is relatively low \(\sim\)30 \(\upmu\)Ci, and expertise with this method is not widespread.
## 4 Simulations
### Voltage Stability Evaluation Index  
To further verify the rationality of the distributed generation and electric vehicle capacity selection results given by the kernel extreme learning machine, the voltage stability evaluation index (_Iuse_) is introduced to evaluate. The value of _Iuse_ for all the nodes before installing wind and photovoltaic are mentioned in Figure 6. The X-axis indicates the node number and the Y-axis indicates the value of the _Iuse_ indicator. Table 3 shows the changes in the indicators with different distributed generation access modes without electric vehicles.  
_Iuse_o_ represents the original _Iuse_ value when the distributed generation is not connected. _Iuse_case1 represents the index value when distributed generation is connected under case1, so as _Iuse_case2 and _Iuse_case3. As shown in Table 3, the _Iuse_ value is gradually decreased compared with _Iuse_o. According to the definition of the _Iuse_, that means the corresponding node voltage stability is improved. So the distributed generation access is helpful to improve the voltage stability.  
_Iuse_case nekev is the value of _Iuse_ when distributed generation and electric vehicles are both connected. As shown in Table 4, the _Iuse_ value decreases as the number of distributed generation and electric vehicles increase. So through comparing the changing trends of _Iuse_, the access of distributed generation and electric vehicles are beneficial to improve the voltage stability.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**DG Access Mode** & **Active Power Loss (kW)** & **Total Cost (Million RMB)** & **DG Capacity (MW)** \\ \hline Case 1(Wind) & 150.69 & 2699.3 & 3.41(5) \\ Case 2(Wind, 1 PV) & 146.73 & 3623.1 & 3.5(5); 1.03(18) \\ Case 3(Wind, 2 PV) & 140.33 & 4525.7 & 3.47(5); 1.02(18); 1.18(32) \\ \hline \hline \end{tabular}
\end{table}
Table 2: Results of kernel extreme learning machine with electric vehicle.
# Registration of Dental Tomographic Volume Data and Scan Surface Data Using Dynamic Segmentation
## 1 Introduction
### Motivation and Contribution of the Thesis  
ICP is the most useful fine registration algorithm and produces accurate results. However, volume data is composed of voxel structures with intensity values and contains no points or normal data. To find corresponding points between volume and surface data to apply to ICP, point data should be segmented from the volume data. In the established registration procedure, the segmented surface is used as a target surface for the ICP algorithm. Hence, the previous works must make considerable effort to ensure good quality segmented surface data, and this requires human input. We are motivated to try and overcome this fundamental limitation of the established registration procedure. Registration does not require fully segmented surface information, but only the corresponding points for the ICP method. Obtaining these points has proven the most challenging step in previous works on segmentation. The proposed method, the modified iterative closest point (MICP) obtains the corresponding points by dynamic segmentation defined by an intensity profile analysis. The remainder of this paper is organized as follows. In Section 2 detailed explanations of the proposed method are given. In Section 3  
Figure 1: Flow chart: the iterative closest point (ICP)-based method, the established registration method.  
the results of the proposed method are shown and a comparison of its effectiveness with that of the established method is provided. Finally, the concluding remarks of the paper are given in Section 4.
# Combined Data Augmentation on EANN to Identify Indoor Anomalous Sound Event
## 2 Materials and Methods
### Data Augmentation Methods  
The data augmentation (DA) approach employed in this paper combines raw audio data augmentation with spectrogram data augmentation. It involves applying a combination of techniques such as Pitch Shifting, Background Noise, Time Stretching, and Time-Frequency Masking to the input sound events, resulting in enhanced audio data. For indoor abnormal acoustic events, we conducted a detailed investigation into the optimal performance of various data augmentation methods and further examined the performance of different combinations of data augmentation. The four types of augmentation methods used in this study were as follows.
# Adaptive Bit-Labeling Design for Probabilistic Shaping Based on Residual Source Redundancy
## 5 Conclusions  
In this paper, a new PAS scheme via bit-labeling design for the JSCCM system is proposed. In contrast to the fixed labeling, an algorithm of adaptive bit-labeling design is proposed according to the source probability and the source code based on the achievable system rate analysis. Simulation results demonstrate that the adaptively designed bit-labelings significantly improve the BER performance of the JSCCM system.  
Conceptualization, C.C. and Q.C.; methodology, C.C. and S.L.; software, C.C.; validation, S.L., L.Z., and Q.C.; formal analysis, C.C. and S.L.; investigation, C.C.; resources, S.L.; data curation, C.C.; writing--original draft preparation, C.C.; writing--review and editing, Q.C.; visualization, C.C.; supervision, Q.C.; project administration, C.C.; funding acquisition, C.C. and Q.C. All authors have read and agreed to the published version of the manuscript.  
This work was supported in part by the National Natural Science Foundation of China under Grants 61901182 and 62101195; the Science Foundation of the Fujian Province, China (Grant No. 2020J05056); the Fujian Province Young and Middle-aged Teacher Education Research Project (No. JAT220182); the Fundamental Research Funds for the Central Universities (ZQN-1008); and the Scientific Research Funds of Huaqiao University (19 BS206, 20 BS105, and 21 BS118).  
Not applicable.  
The authors declare no conflict of interest.
# Comparative Study of Natural Fibres to Improve Insulation in Wooden Beehives Using Sensor Networks
## 2 Materials and Methods
### Sensor Network  
#### 2.3.1 Hardware  
One of the objectives of this work was to implement and test a sensor network for remote hive monitoring. For this purpose, a custom sensor node (Figure 3) was developed to monitor humidity and temperature inside the beehives, as well as external environmental variables (pressure, temperature, and humidity). The sensor's main processing unit is the MC Sentinel V1.1, a microcontroller board designed by the University of Valladolid for rapid IoT prototyping. This board integrates, in a compact form factor, an ESP32 microcontroller, an RTC (DS3231), an SD card holder (to store the data), and an autopower circuit [36]. Additionally, the node features a custom PCB integrating a LoRa radio module [37] and a  
Figure 1: Sketch of the box where the tests were carried out with the lamps and the humidity and temperature sensors in the exterior and interior of the hive.  
Figure 2: **(a)** Inside view of the hives featuring lamps and sensors: on the left is the control hive, and on the right is the hive insulated with black agglomerated cork. **(b)** Thermal camera monitoring.  
186,500 lithium battery holder (battery duration 1 year at 15 min transmission interval) and provides easy-plugging contacts for quick sensor attachment. While the developed node can accommodate various sensors and alternatives, an SHT31 [38] was used for internal beehive monitoring, and an AHT20 [39] and a BMP280 [40] were used for external variable measurement.  
The node can store data independently while also transmitting it via radio. To visualise and store these data in real time online, we developed a gateway. The straightforward yet effective gateway used for the experiments comprises a commercial ESP32 board linked to a LoRa radio module. This setup both prints the collected data via a serial connection and sends it to an online server. Another architecture that we implemented and tested, as cited in [41], is designed for more challenging conditions. It consists of a small single-board computer, the Raspberry Pi 4, connected to an Atmel ATSAMD21G18 microcontroller with an integrated LoRa RFM95 radio module and a 4G modem.
## 4 Conclusions  
The present work studies the use of white oil industry wastewater as direct feedstock in MFCs. MFC systems incorporated an ionic liquid membrane based on methyltrioctylammonium chloride, [MTOA\({}^{+}\)][Cl\({}^{-}\)], as an effective separator for the treatment of white oil refinery wastewater. A high removal of COD of 80% was achieved after nine days of operation, with 105 mV as voltage output and 45 mW/m\({}^{3}\) of power density, respectively. A reduction of other species such as Kjeldahl nitrogen, nitrite, sulfate and ammonium was also found, with a high removal percentage of over 50% in the case of sulfate. Moreover, the analysis of the ionic liquid membrane after use showed a good behavior of this type of separator in contact with the substrate in terms of stability, indicating that MFCs containing ionic liquid based separators are suitable for bioenergy production and simultaneous treatment of white oil refinery wastewater. These preliminary results could be for the application of MFC technology for the treatment of wastewater effluents in white oil refinery industries. Future works may be comprised of several strategies for strengthening electrical performance by mixing different microbial and substrate sources when using white oil refinery industry wastewater as feedstock.  
Figure 4: Voltage output in MFC using polymer inclusion membrane based on 70% \(w/w\) of [MTOA\({}^{+}\)][Cl\({}^{-}\)] using white oil refinery wastewater as feedstock.  
Figure 5: Polarization test of MFCs using white oil industry wastewater as feedstock and a polymer inclusion membrane based on [MTOA\({}^{+}\)][Cl\({}^{-}\)]. Polarization curve for MFCs (V vs. I). Power output curve (P vs. I). Calculations are based on anode liquid volume.  
**Acknowledgments:** This work was partially supported by the Spanish Ministry of Science and Innovation (MICINN) and by the FEDER (Fondo Europeo de Desarrollo Regional), Ref. CICYT ENE2011-25188 and by the SENECA Foundation 18975/JIL/2013 grants.  
**Author Contributions:** [PERSON], [PERSON], [PERSON] and [PERSON] conceived, designed and supervised the experiments. [PERSON] and [PERSON] performed the experiments and contributed to the preparation of the paper; [PERSON] and [PERSON] contributed to the preparation of the paper and analyzed the data; [PERSON] and [PERSON] supervised the experiments and contributed to the preparation of the paper and data analysis.  
**Conflicts of Interest:** The authors declare no conflict of interest.
# Data Gathering Techniques in WSN: A Cross-Layer View
## 5 Routing for Data Gathering in WSN
### Common WSN Routing Protocols for Data Gathering
#### 5.1.2 Opportunistic Routing  
The opportunistic routing approach, which was designed for wireless networks, dynamically chooses paths toward the destination on a per-transmission basis, [PERSON] and [PERSON] [120], [PERSON] and [PERSON] [121]. Opportunistic routing exploits the broadcast nature of wireless communication jointly with the spatial diversity of distributed nodes in a given route such that multiple nodes overhear each packet transmitted by a node. The node that receives the packet successfully and can serve as the best relay toward the destination (e.g., closest to the destination) becomes the next transmitting node. Harnessing opportunistic routing to duty-cycle MAC protocols encounters several obstacles. In synchronous duty-cycle MAC protocols (Section 4), the short time duration in which all nodes are awake (and specifically, all the potential relays are awake and trying to forward the same packet) can lead to artificial congestion and poor wake-time utilization. In asynchronous duty-cycle MAC protocols, since not all nodes are awake simultaneously, the use of overhearing, which opportunistic routing relies on, is limited and requires adaptations such that the transmitter will transmit to multiple relays upon its wake-up (e.g., [122]) or delay its transmission, choosing its relay opportunistically based on channel condition (e.g., [123]).  
In a dense WSN, even under asynchronous duty-cycle MAC protocol, several potential relays can be awake simultaneously, which poses additional challenges when utilizing opportunistic routing. In addition to the relay selection problem--whether a transmitter should wait for the best relay to wake up or compromise on a less preferable relay, reducing its awake period and how long it should wait--it also encounters the collision avoidance problem between simultaneously awake nodes. [PERSON] et al. [124] suggest a slotted contention-based scheme in which, following a probe sent by the transmitter, the awakened potential relays contend and transmit feedback concerning the routing progress they can offer. The transmitter selects the best possible relay out of the ones that replied, taking into account not only the metric chosen to evaluate the different relays, but also the waiting time of the link-layer transmissions. Under a similar set-up of dense asynchronous duty-cycle MAC protocol with multiple potential relays awake simultaneously, [PERSON] et al. [125] try to control the number of potential forwarders, which influences both the transmitter waiting time and the number of packet duplications. The suggested solution relies on a two-step mechanism. First, each transmitter determines a _candidate zone_ such that all nodes within the _candidate zone_ are potential forwarders. Second, the candidates within the _candidate zone_ are prioritized based on a combination of metrics that considers residual energy, transmitting direction, distance, and link quality.
# Fronthaul Design for Wireless Networks
## 3 Fronthaul Design Methodology
### Network Planning Algorithm
#### 3.2.2 Network Planning Algorithm Workflow
Therefore, the previous two steps (computation of BBUs' positions and determination of the total costs of the network) are repeated multiple times--namely a total of \(D_{init}\) times, which is a user-specified value that ideally should be close to \(K^{N(RRHs)}\), although this number may be too time consuming to be practical--in order to search for the cheapest network topology regarding the number of BBUs that is under consideration (e.g., \(min\_BBU\)). The network planning algorithm then computes again the total costs of the network, but now considering a different number of BBUs, in order to find the cheapest alternative. More specifically, the procedure is repeated, sequentially, from the minimum (\(min\_BBU\)) to the maximum number of BBUs (\(max\_BBU\)) defined by the user, and the algorithm will finally return which number of BBUs yields the overall cheapest solution along with other outputs: BBUs positions, RRHs assigned to each BBU, equipment ID for each RRH-BBU link, and total network costs.
## 4 Data Transmission
The secondary services: (i) are not allowed to interfere primary services, (ii) are not allowed to complain against primary services interferences and (iii) are not allowed to complain against previously attributed secondary services interferences. Moreover, each country has an organization to clarify ITU-R suggestions and to authorize to permanently, temporary or experimentally operate at a certain frequency. The radio link we are dealing with, ranges through two ITU-R regions and crosses several countries. Hence a frequency spectrum request should be applied in each country, and of course it should be the same in all of them. Moreover, since the channel frequency availability is time dependent, not just one but several frequency bands along the whole HF frequency band should be requested for operation. As applying for such an international reservation of multiple frequency bands is not a feasible solution, our goal was instead to implement a communication system that should not interfere any other primary or secondary service with permanent, temporary or experimental operation authorization. To achieve it, the communication system should: (i) employ a low transmitting power, (ii) have a low power spectral density and (iii) operate with sporadic and short time transmitting periods. Also it should have a good robustness against noise, interference and time-variant multipath fading. Several HF standards proposed by the NATO, the USA Department of Defense and the Institute for Telecommunications Science that depends on the USA Department of Commerce have been revised and we conclude that none of them satisfies the requirements of this HF link. As a result, a new physical layer solution must be proposed to match the strict requirements of the communication system considered in this project. In the following sections two preliminary physical layer proposals will be addressed.
# OTFS-IM Modulation Based on Four-Dimensional Spherical Code in Air-to-Ground Communication
###### Abstract  
Unmanned aerial vehicles (UAVs) have been widely utilized for their various advantages. However, UAVs exhibit high mobility and energy storage restrictions in some applications, which can compromise the quality and reliability of communication links. This is a challenge that future aircraft and low-orbit aircraft will inevitably encounter. To effectively address the issue of dynamic Doppler spread in air-to-ground communication, this paper creatively introduces four-dimensional spherical code modulation into the orthogonal time-frequency space with an index modulation (OTFS-IM) system. The fundamental concept of the four-dimensional spherical code is elaborated in detail. Multiple resource symbols can be jointly used to increase the modulation dimension, thereby achieving a larger minimum Euclidean distance between constellation points. Furthermore, detailed analysis is conducted on the bit error rate (BER) and the peak-to-average-power ratio (PAPR) expressions of the proposed system to evaluate its performance and provide theoretical guidance. The proposed scheme not only adapts well to high-speed scenarios but also achieves better power consumption efficiency. The simulation results demonstrate that our proposed scheme outperforms conventional methods. Its robustness and generalization ability are also validated.  
orthogonal time-frequency space; index modulation; spherical code; maximum likelihood detection +
Footnote †: journal:  
00 000-0002-3219-2231-2311][PERSON]  
1 School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China; [EMAIL_ADDRESS] (P.G.); [PERSON]ADDRESS] (L.G.)
## 2 Advances and Achievements in Seed Biotechnologies in the Decade 2014-2024
### Seed Quality Improvement Through Biotechnological Innovations
#### 2.2.3 Nano-Enabled Seed Treatment Practices
Reports have suggested enhanced biotic and abiotic stress tolerance in seeds via different molecular mechanisms on nanofertilizer application [135]. [PERSON] and colleagues [136] developed a copper oxide-based nanofertilizer for increased seedling growth in corn. [PERSON] et al. [137] developed a novel nanofertilizer and studied its effect on the yield of _Glycine max_ cv. Kowsar seeds. In the current context, only some studies have reported the use of nanofertilizers in seed development and germination and require further investigations. Nanopesticides have been further utilized for seed protection, and act by inhibiting cell wall synthesis, inhibiting protein and amino acid synthesis, and restricting metabolic pathways in microbes and pests, among others [138]. When used for seed protection, nanopesticide-mediated ROS improves seed defense response by inducing secondary metabolites and antimicrobial peptides and kills seed pathogens. Studies have discussed that nanoparticles induce ROS production in plants, which leads to secondary metabolite synthesis; however, the exact mechanism is less understood [139; 140]. In a key example, iron nanorods were used to develop a nano fungicide and effectively inhibited phytopathogenic fungi growth [141]. [PERSON] et al. [142] developed a nanoformulation composed of thiosemicarbazone for fungal infection control in grains, showing their prospects in seed biotechnologies.