esa-sceva/satcom-chunk-collection huggingface dataset:
# Power Quality Issues and Mitigation for Electric Grids with Wind Power Penetration
## 4 Simulation of Voltage Mitigation
### Results of Selected Case Studies
#### 4.3.1 Transmission System Case Studies
The generators at node \"5\" and node \"8\" provide the maximum reactive power available as shown in Figure 11. Hence, the two generators cannot maintain the terminal voltage at the desired values. Their model is changed from a controlled voltage node to a constant PQ generator model. Similarly, the WPP at node \"30\" cannot maintain the terminal voltage at the PCC since it already delivers all reactive power available from the compensator. The reactive power of the WPP is bounded by Equations (1) and (3). With power generation intermittency, it is quite difficult to regulate the voltage all the time due to the variation of the reactive power limit. The results show that the reactive power generation of the WPP delivers its maximum reactive power during the whole simulation  
Figure 10: The voltage of the voltage-controlled nodes of the IEEE 30-node including a non-dispatchable 10 MW wind farm located at node “30”. Figure 9: The voltage of the generator nodes of the IEEE 30-node and the voltage at node “30” which is a potential candidate to install a non-dispatchable wind farm. period. Hence, with a small WPP in a range of 5% of the total base demand, voltage fluctuations are not fully mitigated using the available reactive power from the WPP. It is important to mention herein, that the voltage variation at PCC of the WPP is not a local problem but also affects other unregulated nodes of the study system. Case 3 System with 50 MW WPP: A higher penetration level is considered for the same system conditions as the above cases. The capacity of the WPP is taken to be 50 MW. The obtained results show that active power dispatch has been changed in the study system. Additionally, the available reactive power for compensation becomes visible for the grid size. Figure 12 shows both the active and the available reactive power for compensation from the WPP. Additionally, the figure exhibits the amount of reactive to be injected into the grid to regulate the voltage at node \"30\" and keep it at 1.06 p.u. In comparison to previous cases without or with a small power plant size, the results exhibited in Figure 13 show that the reactive power compensation mitigates the voltage at PCC and hence it could improve the overall grid voltage profile. Figure 11: Reactive power generation from synchronous machines and the non-dispatchable 10 MW wind farm. Figure 12: Active and reactive power generation of a 50 MW wind farm located at bus “30” of the IEEE 30-node.
# Walkability Compass--A Space Syntax Solution for Comparative Studies
## 3 Results
### The Walkability Compass  
A \"walkability compass\" was designed to compare all eight cities on a single picture. The \"compass\" visually expresses the statistical correlation between four analysed walkability explanatory indices (Figure 7). The background values used for the \"compass\" calculation is provided in Table 5; these data were also used for k-means clustering analysis and synergy insights (Figure 8). At the \"compass\", higher correlation values indicate synergy between walkability components. The tool allows us to compare eight case study cities in terms of strong and weak synergies between walkability aspects. However, the \"compass\" does not allow the evaluation of the numerical values of reachable destination, people, and building perimeter, which could differ significantly between the cases. However, their synergy could be high even within a low inhabitant density with just a few travel destinations if allocated low and adequately in a high population density zone with the random allocation of POI and bus stops.  
The \"compass\" points Re-St values as the most synergising. Because of high synergies in every city between these two indicators, their importance in k-means cluster analysis is relatively low (significance 0.295 according to ANOVA tests where more significant values represent lower importance when maximum could be 1). The application of k-means cluster analysis (input data from Table 5) reveals three walkability synergy clusters (Figure 8). The clusters can be explained using synergising indicators pairs. The first pair is made of Gr-Re and Gr-St. It describes how many travel destinations are attractive for walking city zones because of spatial structure and urban design peculiarities. The second pair made by Re-Pop and St-PoP identifies how many inhabitants live in the walkability zone.  
The first cluster demonstrates the relative mean synergies of Gr-Re and Gr-St and low values of both Re-PoP and St-PoP. The first cluster also shows medium values of the first pair within the context of the presented research and low values of the second pair. Vilniusis the only city in this cluster. The second cluster shows high values of the first pair and high values of the second one--it is \"the ideal\" city in the presented research, and it is Riga. All the other cities are assigned to the third cluster with the lowest values of the first pair and medium values of the second one. Furthermore, the Gr-PoP correlation was not significant during the analysis, possibly because of the small areas with the high gravity concentration identified in pattern analysis--its significance for identifying the clusters, according to ANOVA tests, was low (0.634).
## 3 Theory
### Signal-to-Noise Ratio  
In the signal-to-noise ratio, the integrated peak area of the target element is divided by the root mean square noise multiplied by the peak widths. The integrated peak area of the target element's emission line, the peak width, and the root mean square (RMS) noise are acquired from the spectral emission lines. The RMS noise is obtained from the baseline intensities, which are adjacent to the element emission lines [25].  
\[SNR=\frac{(\text{Integrated peak area})}{(\text{RMS noise})(\text{ Peak width})} \tag{5}\]
## 1 Introduction
### Previous Work and Background  
Several research groups around the globe have presented different algorithms and techniques to improve FSO performance. In [5], the authors have shown recent progress on FSO technology and the factors that interpret the outcomes. The study in [6] evaluates the performance of the FSO system in diverse geographical locations. The channel induced limitations are mitigated using orthogonal frequency division multiplexing (OFDM) and digital signal processing (DSP) techniques. [PERSON] et al. [7] suggested a full duplex and all FSO transceivers and evaluated its performance. The quality factor and electrical power were investigated for FSO links in [8], and simulation analyses were performed using optisystem. Intensity modulation and direct modulation (IM/DD) FSO link were studied in [9] in terms of bit error rate (BER). Ref. [10] explained the OFDM mode division multiplexing (OFDM-MDM) based FSO transceiver. The dust effect is estimated using signal to noise ratio (SNR) and total power as key measuring parameters. The impact of sandstorm conditions was analyzed in [11] for FSO links. The backhaul network was introduced in [12] for a 5G based FSO system, and the performance was evaluated and compared with a conventional FSO link. In [13], the role of the FSO framework was investigated for the next generation satellite communication system. However, the COVID-19 pandemic has given a push to online application and marketing services, which has overburdened the already installed FSO setups. In this paper, the combined structure of the optical network and FSO is introduced to enrich the capacity and transmission accuracy. This mechanism has fruitfully minimized the impacts of FSO pointing and co-channel interference disabilities. This paper is organized as follows. Section 2 consists of an analytical investigation, the proposed mixed FSO and optical network is elaborated in Section 3. Section 4 discusses the results and discussion of the simulation analysis, and, finally, the mixed FSO and optical network model is summarized in Section 5.
###### Abstract  
The clinical use of bioactive material in the field of biomedical tissue engineering has become increasingly of interest in practice. This study investigates how Biodentine(tm) (BD), a tricalcium silicate cement, in culture media, affects the odonto/osteogenic differentiation potential of in vitro cultured human dental pulp stem cells (hDPSCs). hDPSCs were extracted and characterized for their expression profile by flow cytometry. Then, hDPSCs were cultured in media containing BD for 3 weeks to study the impact of BD on the odonto/osteogenesis pathway, compared to the positive control (osteogenic media) and negative control (cell culture media). Odonto/osteogenic differentiation of hDPSCs treated with BD was assessed by measuring the level of expression of odonto/osteogenic markers by flow cytometry, ELISA and Alizarin red stain. Additionally, the expression profile of the genes involved in the odonto/osteogenesis pathway was investigated, using PCR array. Our results indicate that hDPSCs treatment with BD results in an increased tendency for odonto/osteogenic differentiation. The BD treated group demonstrates a significant increase in the expression of odonto/osteogenic markers, osteocalcin (OCN) (\(p<0.005\)), osteeption (OPN) (\(p<0.0005\)) and alkaline phosphatase (ALP) (\(p<0.0005\)), and the presentation of calcium deposits by ARS, compared to the negative control by using \(t\)-test and ANOVA. Moreover, the BD-treated group is marked by the upregulation of genes related to the odonto/osteogenesis pathway, compared to the control groups, specifically the genes that are involved in the bone morphogenic protein (BMP) (\(p<0.05\)) signaling pathway, the activation of the extracellular matrix-related gene (ECMG) (\(p<0.05\)) and the Ca\({}^{2+}\) signaling pathway (\(p<0.05\)), compared to day 1 of treatment by using ANOVA. BD shows a stimulatory effect on the odonto/osteogenic capacity of hDPSCs, suggesting BD as a good candidate and a very promising and useful means to be applied in regenerative medicine to regenerate dentine tissue in clinical settings.  
Biodentine(tm); dental stem cells; DPSCs; odontogenic; osteogenic; differentiation +
Footnote †: journal: Applied Sci. 2021, 11, 7563. [[https://doi.org/10.3390/app11167563](https://doi.org/10.3390/app11167563)]([https://doi.org/10.3390/app11167563](https://doi.org/10.3390/app11167563))
# IPv6 Convergence for IoT Cyber-Physical Systems
## 4 Proposed Approach
### Protocol Packing  
We use the term protocol packing to denote the process of packing one protocol frame inside the payload field of another protocol frame. By adopting this approach, both protocols remain standards-compliant. An example is depicted in Figure 7, where a LoRaWAN frame is packed into the payload field of an IEEE 802.15.4 MAC frame. In this example, the entire LoRaWAN radio PHY frame comprising the preamble, PHY header, cyclic redundancy check (CRC), PHY payload, and frame CRC (for uplink messages only), is simply encapsulated into the MAC payload of an IEEE 802.15.4 frame. Following the pre-pending of the IEEE 802.15.4 MAC header and appending the MAC footer, the hybrid payload is then used as the PHY payload for the complete IEEE 802.15.4 frame.  
A similar approach can be adopted for packing LoRaWAN frames inside IEEE 802.11 frames. We outline this process in Figure 8. In this example, the complete LoRaWAN frame is encapsulated within the network data field of the IEEE 802.11 MAC frame.  
Other data link layer and transport encapsulation targets can be supported using this method. Examples include, and are not limited to, Data Over Cable Service Interface Specification (DOCSIS) [36] and AX.25 [37]. DOCSIS is used for high-data-rate transfer over cable and wireless systems. It is predominately used for high-data-rate transfer, for example, broadband internet and television services. AX.25 was developed by the Tucson Amateur Packet Radio (TAPR) and American Radio Relay League (ARRL) organisations in 1996 with an update in 1998. This is a data-link layer protocol derived from the X.25 protocol and was primarily designed for use in impaired narrowband wireless networks, predominately in the amateur radio bands.  
In our approach, we do not simply encapsulate protocol frame data within the payload field of another protocol; we include additional field eli  
Figure 8: Packing LoRaWAN frames inside an IEEE 802.11 MAC frame.  
Figure 7: Packing LoRaWAN frames inside an IEEE 802.15.4 MAC frame.  
our proposed approach also introduces new challenges, requiring additional research. These include the management of complex fragmentation and defragmentation as a result of reducing the worst-case PDU size below 81 bytes and restricted payload sizes (due to the protocol packing overhead). In addition, the number of packed protocols arising from use within heterogeneous networks may be limited, and the number of interconnections supported is strongly linked to the specific hetnet topology under investigation and requires additional extensive research to fully characterise.
# Fault Detection Method for Wind Turbine Generators Based on Attention-Based Modeling
## 2 Attention-Weighted Long Short-Term Memory Network (AW-LSTM)
### Long Short-Term Memory (LSTM) Networks  
LSTM, also known as long short-term memory neural networks, has been successfully applied to various time series analysis tasks, such as natural language processing, machine translation, and human pose analysis. As the bearing signal in the gearbox is also a special type of time series data, LSTM can be naturally transferred to the gear fault signal prediction task. Structurally, RNN has a single structured hidden layer state, which is good at processing short-term input information, while LSTM adds a memory unit that can process and store long-term information. Therefore, theoretically, it can alleviate the gradient disappearance problem of traditional RNN and has better performance in extracting context information and long-distance dependency relationships of bearing signals. Figure 1 shows the internal structure diagram of a single LSTM unit.  
Compared to the classical RNN-based temporal analysis model, LSTM contains three gates: the input gate \(i_{t}\), the forget gate \(f_{t  
Generally speaking, due to the advantages of the gate mechanism, LSTM often has a strong modeling ability for long-term dependency relationships in time series data compared to RNN networks, and has a certain fault tolerance. Moreover, EMD can effectively decompose high-frequency, low-frequency, and irrelevant components in data signals, which has natural effectiveness for processing nonlinear and non-stationary time series data. Therefore, combining EMD and LSTM, and applying them to gearbox bearing fault signal analysis, can achieve higher fault prediction accuracy. This was also one of the main starting points of this research. Unfortunately, LSTM can only treat data at all time steps equally, and cannot explicitly distinguish the importance and contribution of different data frames to fault prediction. Therefore, the performance improvement achieved by simply applying LSTM is often very limited.
## 3 System Design and Implementation
### Client Server Model  
In a dynamic ad hoc network that we have used in our proposed TestBed, these OBUs in vehicles make service requests to the Control Room, which acts as a central \"server\". As the network is wireless and the server is a singular entity, all clients cannot reach it directly--they might have to traverse a long path before their message reaches the server; thus comes the concept of \"multi-hopping\", where message might have to pass through multiple nodes to eventually reach the destination.  
In such a scenario, the most efficient approach is to handle each aspect of the implementation separately. For this purpose, two parallel applications were developed:  
* The server-side application communicates with multiple clients and sends a response to their individual needs, all at once.
* The client-side application communicates with server and sends a request message in which a rescue team member inserts a message code indicates the required service at a specific location.
## 3 Results and Discussions
### Filling Capacity under Different Process Conditions  
The die castings with a chill vent produced by different pouring conditions are shown in Figure 10. It could be noticed that all die castings had complete shapes and smooth surfaces, but the filling length of the chill vent varied with different process conditions. Therefore, the chill vent could be used to evaluate the filling capacity under different process conditions.  
The filling capacity results are summarized in Table 4. The results indicate that the filling length of the chill vent varied from two grids to four grids. Specially, under the process condition of test No. 1, the chill vent was filled with two grids. Under the process condition of test No. 2, 6, 11 and 16, the chill vent was filled with three grids. Under the process condition of test No. 3 and 4, the chill vent was filled with 3.5 grids. Under the process condition of test No. 5, 7, 8, 9, 10, 12, 13, 14 and 15, the chill vent was filled with four grids. Additionally, under the process condition of test No. 4, 7 and 13, there was obvious flash in front of the chill vent.  
Figure 9: Solidification process of the die casting: (**a**) just beginning to solidify, _ts_ = 0 s; (**b**) inagate solidified, _ts_ = 2.1 s; and (**c**) hot spots position, _ts_ = 4.3 s.  
The test results were processed utilizing the range analysis method (shown in Table 5). The results of range analysis show that the piston velocity of fast stage had an obvious impact. A comparison of the results between 0.8 m/s, 1.6 m/s, 2.4 m/s and 3.2 m/s  
\begin{table}
\begin{tabular}{c c c c c c c} \hline  & & & **Factors** & & & **Results** \\ \cline{2-7}
**Test** & **Melt Injection** & **Piston Velocity** & **Piston Velocity** & **Pressure** & **Filling** & **Shrinkage** & **Gas** \\
**No.** & **Temperature A** & **of Slow Stage** & **of Fast Stage** & **Maintaining Time** & **Capacity** & **Porosity** & **Porosity** \\
**(’C’)** & **B (m/s)** & **C (m/s)** & **D (s)** & **(Grid)** & **(Risk Level)** & **(Risk Level)** \\ \hline
1 & 620 & 0.10 & 0.8 & 1.0 & 2.0 & 2.0 & 2.0 \\
2 & 62  
indicated that an increase in the piston velocity of the fast stage led to a better filling capacity. The melt injection temperature could also affect the filling capacity. The filling capacity would be limited in the condition of the low melt injection temperature. When the melt injection temperature was higher than a certain value, there would be no obvious change in the filling capacity. There was no significant difference between the application of different levels in the filling capacity for both the piston velocity of the slow stage and the pressure maintaining time. Therefore, the filling capacity did not show obvious dependency on the piston velocity of slow stage and the pressure maintaining time.
## 3 Results
### Electro-Optical Measurements of the Optical Links  
The electro-optical measurements for the visible and IR links included the bandwidth, illumination level for the visible link LED, signal-to-noise ratio (SNR), bit rate, bit error rate (BER), packet error rate (PER), and the reach of the optical links. These measurements were conducted in the system shown in Figure 34, where the system was deployed within the passenger van. The maximum optical link length achieved in the passenger van was 72.5 cm, while the maximum optical link length in the set-up shown in Figure 27 was 102.5 cm. The USB dongle within the van was positioned in the passenger seat, where sunlight exposure did not have significant effects on the PD.
## 5 Results
### Comparative Study
#### 5.2.2 Checkerboard Artifact Experiment  
To demonstrate the efficacy of the feature recovery module in LGAR-Net2, we visually depicted the feature images obtained from the BIC block output and provided a comparative analysis with the results achieved by GRCNN. As illustrated in Figure 10, it is evident that the basic network's output exhibits noticeable checkerboard artifacts. However, through bilinear interpolation within the BIC block, as exemplified in columns 3 and 6 of  
Figure 9: Results of the attention comparison experiment, (**a**) image of the target object, (**b**) feature image of the intermediate layer GRCNN network, (**c**) feature image of the LGAR-Net network, and (**d**) feature image of the LGAR-Net2 network after applying LGCA.  
the output images, adjacent pixel values are effectively smoothed out while eliminating these artifacts. This substantiates our proposed BIC block's ability to successfully eradicate checkerboard artifacts and significantly enhance decoder performance.
# Virtual View Synthesis Based on Asymmetric Bidirectional DIBR for 3D Video and Free Viewpoint Video
## 4 Conclusions  
This paper presents a virtual view synthesis method based on asymmetric bidirectional rendering. Compared with single-view rendering, bidirectional rendering can use the effective contents in auxiliary view to fill holes in the virtual view. In order to reduce the computational cost of fully warping the two reference images, an asymmetric bidirectional rendering approach is proposed. The selected regions are extracted by marking the hole edges in the virtual image and locating them in the auxiliary image. Since only the content that is helpful for hole filling is warped, the proposed method can effectively reduce the computational complexity while maintaining the hole-filling effect. To improve the visual quality, depth-image preprocessing is introduced to correct the depth value of foreground edges and color correction is performed before image merging. In addition, for hole regions that are not visible in both reference views, a depth-guided inpainting method is proposed to fill them. The depth information is introduced to improve the priority of background pixels and maintain the contour of the foreground. The experimental results verify that the proposed method can effectively reduce the rendering complexity, and obtain satisfactory results subjectively and objectively. The method in this paper mainly focuses on the improvement of imaging quality and rendering efficiency. There is still a gap between the proposed method and the real-time rendering. In future work, we will consider combining software and hardware to further improve rendering efficiency, such as introducing Graphics Processing Unit (GPU) and Field-Programmable Gate Array (FPGA). Deep learning can provide some inspiration for disocclusion filling. It can improve the adaptability of the scene through a large number of training processes, and present more realistic results in shorter computing time. Moreover, some non-parametric algorithms have been proposed for concave hull extraction in recent years. As they do not obtain the best parameters through iteration, the efficiency and accuracy of extracting the hole layer would be improved to some extent.  
Conceptualization, H.L.; methodology, H.L. and Y.W.; software, H.L.; validation, H.L., H.X. and S.R.; data curation, H.L.; writing--original draft preparation, X.C. and Y.W.; writing--review and editing, X.C., H.L. and H.C.; supervision, X.C.; project administration, X.C. and Y.W. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Major Project of Scientific and Technical Supporting Programs of China during the 13 th Five-year Plan Period, grant number 2017 YFC0109702, 2017 YFC0109901 and 2018 YFC0116202.  
The authors would like to thank the Interactive Visual Media Group at Microsoft Research for making the MSR 3D Video Dataset publicly available.  
The authors declare no conflict of interest.