esa-sceva/satcom-chunk-collection huggingface dataset:
# LoRa Enabled Smart Inverters for Microgrid Scenarios with Widespread Elements
## 2 LPWAN Overview  
LPWAN is largely linked with IoT [9]. By paying attention to the definition of IoT, it can be understood that most of the modern smart systems, if not all, fit into this category. Smart-cities, smart-agriculture, smart-grids, MGs, and many more are examples of smart systemsthat can be considered as IoT structures [10]. Among different classes of communication systems, LPWANs are more suited to deal with the widespread and low-power nature of devices that are used in an IoT structure because of their unique characteristics. Generally, these are some key features shared among different LPWANs:  
* Long-range, on a scale of several kilometers or more depending on the operating environment.
* Suitable for none-latency-sensitive applications, since throughput is normally sacrificed to gain larger coverage in LPWAN methodologies [11; 12].
* Large scale deployment that is the essence of IoT ideology.
* Operation inside unlicensed frequency bands so there are no additional costs to pay for a licensed band registration.
* Mostly used for asymmetrical communication scenarios (such as monitoring), which means the nodes can hibernate (not listening) for long intervals and just become alive and transmit when required. This contributes to the conservation of battery energy.  
LPWANs provide a similar range with wide area networks (WAN), based on cellular technologies, while consuming lower energy and providing less throughput. Other classes of wireless networks such as local area networks (LAN), personal area networks (PAN), and low-power local-area networks (LPLAN) are utilized for different applications. LANs normally run on different versions of WiFi which are high-power and high-throughput technologies, their applications are mostly in accordance with human-user-interfaces which require high data-rate features. LPLAN protocols are mainly used for short to medium-range M2M communication scenarios where the throughput can be sacrificed to achieve higher battery lives. PAN is based on very short range protocols that were specifically designed with strict power and security considerations in mind, Figure 1.  
The leading LPWAN technologies are Sigfox, LoRaWAN, Dash7, and Ingenu, which are more recognized among others [13]. All of these LPWAN technologies are basically short-range protocols that achieve cellular-like coverage by manipulating physical layer characteristics. For example, in LoRa, changing the SF leads to sacrifice range for throughput and the other way around [14].
## 3 Results and Discussion
### Effect of Pomelo Cultivars on Volatile Compounds of the juice  
Aroma, composed of a large number of volatile compounds, is one of the sensory properties of fruit juice and has a great effect on the acceptance of fruit juice [49]. As shown in Figure 5, the correlation of volatile compounds of different pomelo juices was evaluated by principal component analysis (PCA). The first two principal components extracted accounted for 57.3% (PC1 29.0%, PC2 28.3%). The scatter points corresponding to the samples of the 12 groups showed clustering with each other within the groups, indicating that the repeatability within the groups was relatively good. The LPPU, LPSU, LPWU, HPGU, HPWU and HPPU were highly clustered, and were located in the negative quadrant of PCA1 and the positive quadrant of PCA2, while for other samples there was no aggregation between groups, revealing that there were differences in the flavor composition of pomelo juice of different cultivars. In order to further study the volatile compounds composition of different pomelo juices, the relative contents of volatile compounds in different pomelo juices were analyzed (Figure 6). A total of 79 volatile compounds were detected, including thirty hydrocarbons, twenty alcohols, ten aldehydes, eight esters, five ketones, two acids and four others. The most types of volatile substances were detected in LPLU (41), followed by HPGT (40). Hydrocarbons accounted for the highest proportion in volatile compounds of pomelo juices. Among these detected hydrocarbons, limonene and carophyllene were determined in all pomelo juices. Limonene was an important citrus aroma compound and one of the main components of the juice, which was consistent with previous reports in the studies [50]. LPGT exhibited the highest relative content of limonene (1.257 mg mL\({}^{-1}\)); almost half of the LPGT volatiles were contributed by limonene, followed by HPSU (0.979 mg mL\({}^{-1}\)). In addition, the carophyllene relative content of LPGT was the highest among these pomelo juices (1.682 mg mL\({}^{-1}\)), which was mainly derived from citrus peel and had a cultivar of important pharmacological activities [51]. With respect to alcohols, the relative content of alcohols in HP juice was higher than those in LP juice. 3-hexen-1-ol, (Z)- was identified in all pomelo juices, which was the dominant alcohol of pomelo juice and had a strong aroma of grass. The highest relative concentration of 3-hexen-1-ol, (Z)- was found in HPGU (0.367 mg mL\({}^{-1}\)), whereas \(\alpha\)-terpincol was only detected in HPGT juice. 2-button-1-ol, 3-methyl-, 1-butanol, 3-methyl- and 3-hexen-1-ol were only found in LPLU. Regarding aldehydes, more categories of aldehydes were measured in HP juices than in LP juices and the HP juices also had a higher relative level of aldehyde. 2-hexenal was the major aldehyde of pomelo juice, which was measured in all samples. 2-ocrenal, (E)- was only detected in LPGU. However, none of the esters were measured in any of the pomelo juices. According to previous research, ethyl acetate was the main ester in juice and it had a fruity
# Optimizing Service Placement for Microservice Architecture in Clouds
## 5 Evaluation
### Impact of Threshold \(\alpha\)  
In this section, we discuss the impact of threshold \(\alpha\) on the service-based application placement. To illustrate, we fix the threshold \(\alpha\) by using BP-HP on the cluster with homogeneous machines. Figure 6 shows the successful placement ratio with different values of threshold \(\alpha\). For instance, BP-HP can find a placement solution for 77% of the applications with 64 services when \(\alpha=0.5\). We observe that the successful placement ratio decreases when the value of threshold \(\alpha\) increases in general, and few applications can be successfully placed when \(\alpha>0.7\). Higher threshold \(\alpha\) leads to less parts and larger average resource demands of parts in the partition, so it becomes harder to pack them into machines with multi-resource constraints. To understand the impact on the network traffic, Figure 7 shows the results of average co-located traffic ratio for each value of threshold \(\alpha\), and the error bars represent the maximum and minimum ratio. It explicitly demonstrates that the co-located traffic ratio increases more when \(\alpha\) is larger. However, larger threshold \(\alpha\) increases the difficulty of packing the applications. Thus, we try to find an appropriate threshold \(\alpha\) by enumerating from large to small in the proposed algorithms.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Scheme**} & \multicolumn{2}{c}{**Homogeneous Cluster**} & \multicolumn{2}{c}{**Heterogeneous Cluster**} \\  & **Avg.** & **Min.** & **Max.** & **Avg.** & **Min.** & **Max.** \\ \hline BP-HP & 48.1 & 35.2 & 56.9 & 50.3 & 37.9 & 60.5 \\ KP-HP & 45.3 & 30.8 & 59.1 & 49.0 & 35.2 & 61.1 \\ KS & 23.3 & 17.1 & 31.4 & 25.6 & 20.4 & 32.8 \\ FFD & 10.0 & 6.5 & 15.8 & 10.9 & 6.2 & 17.1 \\ BFD & 10.9 & 6.4 & 17.2 & 11.1 & 7.3 & 16.6 \\ PACK & 10.5 & 6.1 & 16.3 & 10.7 & 6.1 & 16.5 \\ RAND & 10.6 & 6.2 & 16.7 & 11.0 & 6.8 & 16.8 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Co-located traffic ratio (%) of different schemes.  
Figure 5: Comparison of average co-located traffic ratio of different schemes.
# Experimental Study on the Features of Infrasonic Waves of Sandstone under Shear Load
## 2 Experiment to Acquire Infrasonic Signals during Sandstone Shear Destruction  
### Experimental System  
To determine the features of infrasonic waves generated during sandstone shear destruction, a set of experimental apparatus testing the infrasonic waves generated by rock under shear loading was built (Figure 1), mainly including the rock shear loading system and infrasound acquisition system.
# A High Power Factor LED Driver with Intrinsic Current Balancing Capability
## 2 Analysis of the Proposed LED Driver Circuit  
By integrating a flyback converter and a Class-D series resonant converter, the novel single-stage LED driver was proposed, as shown in Figure 1. The load was composed of four strings of LEDs. There were two MOSFETs, \(S_{1}\) and \(S_{2}\), with intrinsic body diodes \(D_{S1}\) and \(D_{S2}\), respectively. The flyback converter consists of a coupled inductor \(T_{1}\), a MOSFET \(S_{2}\), a diode \(D_{1}\), and a dc-link capacitor \(C_{dc}\). It is operated at a discontinuous-conduction mode (DCM). In this way, in each high-frequency cycle, the primary current of \(T_{1}\) is triangular-shaped, and its peak value in each high-frequency cycle forms a sinusoidal envelope. A low-pass filter (\(L_{f}\) and \(C_{f}\)) can remove the high frequency components of the primary current and the input line source only needs to provide the average value. The series resonant converter consists of \(S_{1}\), \(S_{2}\), a resonant tank (\(L_{r}\) and \(C_{r}\)), a diode \(D_{3}\), and a differential-mode transformer \(T_{2}\). The turn ratio of \(T_{2}\) is equal to one. Therefore, the primary and secondary currents of \(T_{2}\) are equal.  
The input voltage is sinusoidal.  
\[v_{in}(t)=V_{m}\sin{(2\pi f_{L}t)}, \tag{1}\]  
where \(f_{L}\) and \(V_{m}\) are the frequency and amplitude of the input voltage, respectively.  
\(S_{1}\) and \(S_{2}\) are alternatively turned on and off by two high-frequency gate voltages, \(v_{GS1}\) and \(v_{GS2}\). They are a pair of symmetrical and complementary and square wave voltages. There is a short deadtime between them to avoid simultaneous conduction of \(S_{1}\) and \(S_{2}\).  
To simplify the circuit analysis, the following assumptions were made:  
1. All components are considered ideal;
2. The leakage inductance of \(T_{1}\) and \(T_{2}\) is negligible in comparison to the magnetizing inductance;
3. The switching frequency (\(f_{s}\)) of \(S_{1}\) and \(S_{2}\) is far higher than \(f_{L}\), thus, \(V_{in}\) is considered constant in a high-frequency period;
4. The capacitances \(C_{dc}\) and \(C_{01}\)-\(C_{04}\) are large enough so that the voltages across them (\(V_{dc}\), \(V_{01}\)-\(V_{04}\)) are constant at steady-state operation;
5. The current of each LED string is equal. (\(I_{LED1}=I_{LED2}=I_{LED3}=I_{LED4}=I_{LED}\)).  
Figure 1: Proposed single-stage LED driver.  
Based on these assumptions, there will be six modes of operation in a high frequency cycle at a steady state. Figure 2 shows the current loops for each mode, where \(v_{rec}\) is the rectified line voltage and \(R_{1}\)-\(R_{4}\) represent the equivalent resistance of these four LED strings. Figure 3 illustrates the key waveforms of the proposed circuit in high-switching cycles. The circuit operation of each mode was analyzed as follows.
###### Abstract  
In jointless bridges, a grade flat approach slab (GFAS) with the same elevation as the pavement can transfer the girder's longitudinal deformation to the backfill. However, any cracks and settlement of the pavement usually occur at the end of the GFAS. To address this shortcoming, the buried flat approach slab (BFAS) horizontally embedded at a depth in the backfill was proposed. The complicated flat approach slab-soil interaction (FASSI) of the BFAS has not been systemically investigated. To address this gap, the influence of the FASSI on the mechanical performance of the approach slab and the backfill deformation was investigated in this research to understand the mechanism of the FASSI in absorbing one part of the girder's longitudinal deformation and transferring the rest to the soil. Experimental tests on the FASSI with different embedded depths under longitudinal displacements were conducted. Numerical parametric analyses were carried out by considering the embedded depths and slab lengths as the parameters based on a finite element model verified using the test results. The results show that load-displacement curves of the FASSI comprise three stages: the elastic stage (approach slab's displacement was absorbed by sand), the elastoplastic stage (sand deformation was observed), and the failure stage (overall shear failure of the sand was found). The longitudinal displacement transfer mode and vertical deformation distribution mode of the sand were affected by the embedded depth and slab length. With an increase in the embedded depth or a decrease in the slab length, the sand deformation decreases, which is beneficial for avoiding pavement crack risks and improving the pavement evenness. Finally, a simplified calculation formula that can be used to predict the load-displacement curves of the FASSI was proposed. This research provides the theoretical basis for the design and construction of the flat approach slab in jointless bridges.  
jointless bridges; flat approach slab; approach slab-soil interaction; load-displacement curve; sand deformation; simplified calculation formula +
Footnote †: journal: Applied Sciences
# Metrics-Based Comparison of OWL and XML for Representing and Querying Cognitive Radio Capabilities
## 6 Discussion  
The objective of this section is to discuss how the method satisfies the requirements stated in Section 1.2 and why the techniques used in the method are a good fit for our problem.  
Clearly, the main challenge is to assure that the proposed method is fair to the two representation formalisms--XML and OWL. The first step is to use the same inputs and the same evaluation metrics. The problem is that the inputs and the queries must be expressed in two different languages. To assure a relatively good level of fairness, we had to rely on mappings between the languages that were as good as possible. We relied on the fact that OWL uses XML as one of the syntaxes. Thus, the same randomly generated device descriptions were expressed in the XML syntax of OWL and used by both XML and OWL based matchers. Second, queries were expressed in SPARQL and then translated using the xql2 xquery tool, whose translation completeness and correctness is assured [32; 33]. The same metrics (recall, precision and F-measure) were used to assess both approaches.  
One of the most difficult issues was the ground truth--how to assess whether a given selection of the devices to satisfy a given query is correct. In our approach we used a \"relative\" rather than \"absolute\" definition of ground truth. Since our objective was to assess the value added by OWL inference, we used the most complete knowledge base as the reference and then compared the performance of the OWL-based matcher using progressively less complete knowledge bases. This approach did not impact the fairness of the comparison between the matchers, since the XML-based matcher provided the most complete information for each of the cases.  
The coverage of the space of device descriptions used in our experiments was evaluated in [8], where it was shown that the SDR ontology used in the experiments provides good coverage of the knowledge of various types of RF devices and has extensive coverage of the OWL axioms. Second, the queries used in our experiments were assessed by various evaluation metrics in [9], and it was shown that the coverage of the query space is good.  
Since RODG, SQG, xql2 xquery, the OWL-based query processor (DeVISor), and the XML-based query processor (BaseX) can all handle large amounts of data, the method is able to deal with large-sized datasets and query sets and can extend to updates of the background knowledge, datasets, query sets, and metrics.
# Parametric Optimization Study of Novel Winglets for Transonic Aircraft Wings
## 2 Wing and Winglet Models
### Conventional and Proposed Winglets  
All winglets were designed based on the constraint that the projected wingspan be constant. Conventional winglets such as raked, blended, and wingtip fence winglets were modeled by referring to multiple research papers [6; 8; 9; 10; 13; 19; 29; 30]. The designs from the mentioned literatures were used for comparison with this study's novel winglet designs. The dimensions of the conventional designs are shown in Figure 2. The proposed and novel winglet designs such as twisted, multi-tip, and bird-type were modelled by representing the nature of a bird's feather, as shown in Figure 3. The finger-like wingtips of birds help reduce induced drag by creating small vortices on each tip than forming a big vortex at the wingtips, which generally occurs in aircraft.  
Figure 1: NASA CRM wing model.  
Figure 3: _Cont._  
Figure 2: A Schematic of (a) blended, (b) raked, and (c) fence winglets.  
It has been witnessed that twisted, multi-tip, and bird-type winglets have great potential in reducing drag; thus, these designs were considered for this work. Multi-cant angles give a better aerodynamic performance at a different angle of attack, and thus, multi-tip and bird-type winglets enhance drag reduction. Twisted winglets help in reduction in the wing root bending moment and also tip by being at a negative angle of attack, which stall late compared to the root of the wing.
# A Roadmap for Gigabit to Terabit Optical Wireless Communications Receivers
## 3 Results
### Impact of Non-Linearity on BER
Furthermore, these results indicate the possible impact of the finite width of the fast output pulses. In particular, in previous experiments with a J30020, a data rate of 3 Gbps was achieved at an irradiance of approximately 100 mW\({}^{-2}\)[11]. In contrast, the results in Figure 4b show that, if the width of the fast output pulses is zero, a data rate of 50 Gbps could be achieved at this irradiance. These simulation results show that SiPMs' non-linearity is not the factor that has previously limited the data rates that have been achieved.
## 3 Results and Discussion
### Heavy Metals Content in Raspberry Leaves
In the second year of harvest, cobalt contents in all crops were lower, which is consistent with the findings of other authors [41]. On the other hand, the Co content in raspberry leaves, determined by [PERSON] et al. [42] was 0.42 mg kg\({}^{-1}\). The examined raspberry leaves from the second harvest year had significantly lower Cr contents compared to those collected in 2020. The content of this element noted by [PERSON] [41] and [PERSON] et al. [42] and was about 1 mg kg\({}^{-1}\). The results obtained for molybdenum content in raspberry leaves were within the range given in another study, which was 4-21 mg kg\({}^{-1}\) DM [41]. The upper limit was also reported by [PERSON] at al. [42]. The manganese content was different in all examined samples, and the highest was in the leaves of wild-growing raspberry harvested in 2020. The results reported by other authors were significantly lower than our findings [34; 41; 42; 43; 46]. A higher manganese content was also observed than in our samples, excluding the leaves of wild raspberry from the second year of cultivation [47]. Low pH, the presence of clay soils, the water-air imbalance as well as the activity of rhizosphere bacteria may cause the accumulation of manganese in the plant [48; 49]. Copper content was similar and statistically significant for each raspberry crop with regard to each harvest year. Cu contents given in the available literature are lower [28; 33; 34; 42] or higher [41; 43; 46; 47] compared to our results. Similar observations referring to Cu content were reported by other authors [45]. The study by [PERSON] and [PERSON] examined the three cultivars 'Glen Ample', 'Laszka' and 'Radziejova'. The content of copper in each variety was higher than in the study [44]. As for boron, its content in leaves of wild-growing and organically cultivated raspberry was similar; however, it was different than that established for the leaves derived from conventional farming, for which its amounts in successive crops were 75.38 mg kg\({}^{-1}\) and 117.02 mg kg\({}^{-1}\). These values were statistically significant both among themselves and in comparison with other crops. The results obtained by other authors were either in the range of our results [41; 47] or were lower [45; 46]. No literature was found to confirm the contents of vanadium, strontium, antimony, titanium and thallium in raspberry leaves coming from different crops.
## 3 Results
### Efficacy (According to Positions, Location and Angle)  
Regarding efficacy, within-group analysis revealed that positions affected efficacy for the U16 group, with statistically significant differences (\(F_{(9:490)}\) = 3.366; \(p=0.001\); \(\eta^{2}=0.058\); minimal effect size, \(\pi\) = 0.986). We found better efficacy when comparing between position 1 and position 6 (\(p\) = 0.001), position 1 and position 10 (\(p\) = 0.001), position 3 and position 6 (\(p\) = 0.035), position 5 and position 6 (\(p\) = 0.009) and between position 6 and position 7 (\(p\) = 0.035) (Table 1).  
Between-group comparisons indicated that professional players obtained better overall results than the U16 group in almost all shooting positions (\(t_{(9998)}=-6.870\); \(p=0.001\); \(d=0.862\); large effect size) and angles with the exception of positions 2, 6 and 10, and angle 180\({}^{\circ}\).
# Monitoring Changes in the Enhanced Vegetation Index to Inform the Management of Forests
## 3 Results
### Drivers of Change
Interestingly, for positive breaks, summer CMI predictors showed lower non-monotonic curves (Figure A5c-e,g). Notably, the curve of summer CMI with a 2-year lag was roughly U-shaped. It showed relatively high values (above 950) associated with drought-like conditions, corresponding to negative CMI values. There was a dip when CMI values were close to zero and an increasing trend for values higher than 5 (Figure A5c). When using the data subsets, the effect of protection status on the magnitude of positive abrupt changes (positive breaks) is relatively minor, as shown by the shallow increasing slope between protected and non-protected forests (Figure A5h). Interestingly, non-protected status was associated with a slightly higher value of greenness (positive break magnitude) compared to protected status. This may be due to plantation regrowth occurring in timber harvest areas. Protection status has no association with the magnitude of negative abrupt changes (Figure A4i).
# Perceptual Similarities between Artificial Reverberation Algorithms and Real Reverberation
###### Abstract  
This paper presents a study evaluating the perceptual similarity between artificial reverberation algorithms and acoustic measurements. An online headphone-based listening test was conducted and data were collected from 20 expert assessors. Seven reverberation algorithms were tested in the listening test, including the Dattorro, Directional Feedback Delay Network (DFDN), Feedback Delay Network (FDN), Gardner, Moorer, and Schroeder reverberation algorithms. A new Hybrid Moorer-Schroeder (HMS) reverberation algorithm was included as well. A solo cello piece, male speech, female singing, and a drumbeat were rendered with the seven reverberation algorithms in three different reverberation times (0.266 s, 0.95 s and 2.34 s) as the test conditions. The test was conducted online and based on the Multiple Stimuli with Hidden Reference and Anchor (MUSHRA) paradigm. The reference conditions consisted of the same audio samples convolved with measured binaural room impulse responses (BRIRs) with the same three reverberation times. The anchor was dual-mono 3.5 kHz low pass filtered audio. The similarity between the test audio and the reference audio was scored on a scale of zero to a hundred. Statistical analysis of the results shows that the [PERSON] and HMS reverberation algorithms are good candidates for exploration of artificial reverberation in Augmented Reality (AR) scenarios in future research.  
reverberation algorithm; BRIR; MUSHRA; Hybrid Moorer-Schroeder (HMS)