esa-sceva/satcom-chunk-collection huggingface dataset:
# Power Stability Analysis and Evaluation Criteria of Dual-Infeed HVDC with LCC-HVDC and VSC-HVDC
## 4 Evaluation Criteria for the Power Stability of Hybrid Dual-Infeed HVDC Systems  
### Effective Short Circuit Ratio (ESCR)  
For single-infeed LCC-HVDC systems, the ESCR index can be used to evaluate the power stability of HVDC systems [10; 11; 12]. Whether the ESCR index can still be used to quantitatively evaluate the power stability of hybrid dual-infeed HVDC systems is the focus of this paper. The ESCR is defined as:  
\[\text{ESCR}=\frac{S_{\text{c}}-Q_{\text{CN}}}{P_{\text{dN}}} \tag{25}\]  
where \(S_{\text{c}}\) is the three-phase short circuit capacity of the converter bus. \(Q_{\text{CN}}\) is the rated reactive power provided by the filters and compensators in the converter station, and \(P_{\text{dN}}\) is the rated DC power of the converter station.  
Study on the Effectiveness of Effective Short Circuit Ratio on the Power Stability of Hybrid Dual-Infeed HVDC Systems  
The power stability margin of hybrid dual-infeed HVDC systems at the rated operating point is the most concerning issue in power grid planning and operation. Unlike the single-infeed LCC-HVDC system, the analytical expression of the critical effective short-circuit ratio cannot be derived theoretically for the hybrid dual-infeed HVDC system. Therefore, in the following analysis, the PSI-ESCR curves under different system parameters are compared to investigate whether there is a clear one-to-one correspondence between PSI and ESCR at the rated operating point. According to the analysis in Section 2.2, under the premise of clear system parameters, the maximum power curve \(P_{\text{d1}}\)-\(I_{\text{d1}}\) of LCC-HVDC can be obtained by adjusting the value of \(I_{\text{d1}}\), and then the PSI value at the rated operating point can be calculated. Furthermore, the relationship between PSI and ESCR can be obtained by adjusting the value of the impedance parameter \(Z_{1}\). The specific calculation process is shown in Figure 5, where \(\Delta I_{\text{d1}}\) and \(\Delta Z_{1}\) denote the simulation step.  
Figure 4: Maximum power curves of LCC-HVDC under different VSC-HVDC transmission power: (**a**) Constant reactive power control mode; (**b**) constant AC voltage control mode.
## 5 Enhancement of Brillouin Stokes Signal (II): Influence of Core Diameter and Fiber Length
### Motivation  
As described in Section 3, the power of the SpBS Stokes light generated in the PFGI-POFs with 120-\(\upmu\)m core diameter was quite low, and it needs to be enhanced for detailed investigations of the BGS [39] including the linewidth narrowing effect. Since the BGS observed with the pump-probe technique described in Section 4 is easily influenced by the time constant of lock-in detection, detailed evaluation of its linewidth was not feasible. Another approach to enhance the Stokes signal is to make use of PFGI-POFs with core diameters smaller than 120 \(\upmu\)m. Although PFGI-POFs with 62.5-\(\upmu\)m core diameter have become commercially available very recently (Sekisui Chemical Co., Ltd., 2011), no study has been reported on their Brillouin scattering properties. Therefore, in this Section, we characterize the BGS in PFGI-POFs with 62.5-\(\upmu\)m core diameter.
## 4 Conclusions  
The simple solution mixing method using variable amounts of graphene content (10, 30, and 50 wt%), the HfO\({}_{2}\)-graphene nanocomposite, was prepared. More than the HfO\({}_{2}\) nanoparticles, the HfO\({}_{2}\)-graphene nanocomposite showed notably higher efficacy of photodegradation. By HR-TEM, it was confirmed that the HfO\({}_{2}\) nanoparticles had been distributed on the graphene sheets. The chemical composition of C, O, and Hf were analyzed by EDX. Using the HfO\({}_{2}\)-graphene nanocomposite as a catalyst, the MB solution's degradation was analyzed through UV light irradiation. As a result, 99% of MB dye removal  
Figure 10: Proposed reaction mechanism for the photocatalytic dye degradation of MB dye by HfO\({}_{2}\)-graphene (50 wt%) nanocomposites under UV illumination.  
Figure 9: Photocatalytic efficiency of tetracycline degradation as a function of irradiation time under UV light using HfO\({}_{2}\)-graphene (**A**). Rate of degradation of tetracycline under UV light (**B**).  
was achieved. The HfO\({}_{2}\)-graphene (50 wt\(\%\)) photocatalyst degrades 81 \(\pm\) 2% of tetracycline in 180 min. It reaffirms that the HfO\({}_{2}\)-graphene nanocomposite can effectively degrade MB dye and tetracycline under UV light irradiation, which can be applied optimally for proper wastewater management.  
[PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] conceived the project; [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON], performed the experiments, generated datasets, and wrote the first draft of the manuscript; [PERSON], [PERSON] and [PERSON] supervised the project and edited and revised the manuscript; All authors have read and agreed to the published version of the manuscript.  
Global Korea Scholarship (GKS) Program through the National Institute for International Education (NIED), funded by the Ministry of Education Republic of Korea. The authors thank the Core Research Support Center for Natural Products and Medical Materials (CRCNM) for technical support regarding the nanoindentation test.  
Not applicable.  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
No data were used for the research described in the article.  
This research was supported by the Global Korea Scholarship (GKS) Program through the National Institute for International Education (NIED), funded by the Ministry of Education Republic of Korea. The authors thank the Core Research Support Center for Natural Products and Medical Materials (CRCNM) for technical support regarding the nanoindentation test. The first author, [PERSON], is grateful to the Korean Ministry of Education for awarding the GKS to support the research program. S.C. was supported by a Grant-in-Aid for Early-Career Scientists fund (KAKENHI No.22K15249) by Japan Society for the Promotion of Science.  
The authors declare that they have no competing interests.
# Deduplication-Aware Healthcare Data Distribution in IoMT
## 3 System Model and Problem Statement  
The system model shows patients and employees with sensor nodes on their garments and bodies to obtain healthcare data values for further transmission. The collector node, having access to onboard sensors, can gather the sensed data from the connected devices. The data readings contain redundant values, such as those reflecting the body temperature of a patient, which do not fluctuate quickly. The same applies to the BP, ECG, oxygen saturation level, etc. These duplicated values need to be recognized before transmitting the data to the server so that the communication costs can be reduced. The first layer performs the function of data aggregation from the attached body sensors. The second one includes a fog layer situated at the cloud's edge. Fog servers possess the capability to evaluate a patient's health condition based on the obtained data readings and communicate with the collector node to take immediate action if needed. The third and last one is the cloud layer, serving as the foundation for the processing of the data and their storage, as illustrated in Figure 1.  
The core issue in the basic techniques is that the variable-sized windows can be much smaller in size; this is dynamically calculated on the basis of a breakpoint. It may affect the average chunk size, which should be large so as to identify more duplicate values and obtain better deduplication ratios. There could be a scenario in which the LMB is not found based on schemes such as RAM and CWCA due to mismatching the criteria used to find the breakpoint. This ultimately results in an uncertain situation or failure to start the subsequent window. In the current study, we implemented the same functionality as in RAM by including windows of both static and variable size. To recognize breakpoints in variable-sized windows, the scheme traverses the incremental side of the window next to a static-sized window. This results in successful cut-point identification by varying the chunk size until a valid breakpoint is identified, as explored in detail in the next section.
## 3 Results and Discussion
### Effect of DES Ratio  
To investigate the role of the (ChCl:ZnCl\({}_{2}\)) DES in the depolymerization of KL, experiments were conducted with varying DES-to-lignin ratios (1:1, 3:1, 5:1, and 7:1) at 190 \({}^{\circ}\)C for 8 h, as illustrated in Figure 3C. At a DES-to-lignin ratio of 1:1, the liquid yield reached its peak at 54.44%, while the RL yield reached 45.56%. However, further increasing the DES-to-lignin ratio to 3:1 resulted in a considerable decline in the liquid product yield to 25.15%, while the RL yield increased to 74.85%. This trend of decreasing liquid product yield and increasing RL yield was also observed for DES-to-lignin ratios of 5:1 and 7:1. At a DES-to-lignin ratio of 7:1, the liquid product yield dropped to 7.21%, while the RL yield increased to 92.79%, indicating insufficient interaction between the DES and lignin. This is because higher DES-to-lignin ratios led to increased viscosity of the DES, which reduced the efficiency of energy conversion and the solubility of lignin during its depolymerization [36].
## 10 Results
### Mesh Throughput Results
#### 10.1.2. Stope vs. Tunnel  
The results also indicate that the throughput performance of both mesh routing protocols in the stope was better than in the tunnel. This is contrary to the previous belief that wireless communications suffer from degradation due to the nature of slopes. With Wi-Fi6's introduction of OFDMA, BSS Colouring, and MU-MIMO in both uplink and downlink, as well as improved beamforming technologies, it has become much smarter, with the ability to cope in high-density environments. This capability has resulted in Wi-Fi6 being able to make much more efficient use of the spectrum, which allows it to utilize the benefits of the waveguide affect provided by a stope. Wi-Fi6 recognizes and uses the waveguide properties of a stope to its advantage, improving signal quality and the resulting throughput results compared to the open tunnel.
###### Abstract  
The transmission rate between two nodes is usually very low in underwater acoustic networks due to the low available bandwidth of underwater acoustic channels. Therefore, increasing the transmission parallelism among network nodes is one of the most effective ways to improve the performance of underwater acoustic networks. In this paper, we propose a new collision-free hybrid medium access control (MAC) protocol for distributed multi-channel underwater acoustic networks. In the proposed protocol, handshaking and data transmission are implemented as a pipeline on multiple acoustic channels. Handshaking is implemented using the time division multiple access (TDMA) technique in a dedicated control channel, which can support multiple successful handshakes in a transmission cycle and avoid collision in the cost of additional delay. Data packets are transmitted in one or multiple data channels, where an algorithm for optimizing the transmission schedule according to the inter-nodal propagation delays is proposed to achieve collision-free parallel data transmission. Replication computation technique, which is usually used in parallel computation to reduce the requirement of communication or execution time, is used in the data packet scheduling to reduce communication overhead in distributed environments. Simulation results show that the proposed protocol outperforms the slotted floor acquisition multiple access (SFAMA), reverse opportunistic packet appending (ROPA), and distributed scheduling based concurrent transmission (DSCT) protocols in throughput, packet delivery rate, and average energy consumption in the price of larger end-to-end delay introduced by TDMA based handshaking.  
Keywords:underwater acoustic network; medium access control; multi-channel; parallel transmission; pipeline; replication computation +
Footnote †: journal: Electronics
# An Embedded System Based on Raspberry Pi for Effective Electrocardiogram Monitoring
## 3 The ECG Circuit Design
### The Schematic Diagram of the ECG Circuit
#### 3.2.2 The Right Leg Drive (RLD)  
The RLD circuit (labeled as Right Leg Drive) in Figure 2 is used to reduce any common mode interference from the amplifier. Through using the RLD, the average common mode signal is amplified and inverted back into the patient's right leg through the third lead. Thus the 50 Hz noise from the AC power will be cancelled and a cleaner ECG output signal will be created. The common mode rejection ratio can be improved by increasing the gain that can be used in the feedback loop. Also, the attenuation needed from the common mode rejection of the instrumentation amplifier can be relaxed by canceling the noise through using RLD. Although it is very important to use the RLD in biomedical systems, it was not used in previous literature [11; 25]. As a result, their published ECG signals are not clean and most of the important peaks are either missing or not clear.
## 3 Simulation and Analysis  
We compute the locations of the available GNSS reflections on the Earth's surface in the case where the signals are transmitted from approximately 120 navigation satellites and are received by the eight LEO GNSS-R instruments using the methods that were proposed in Section 2. To explore advantages of the multi-GNSS-R technique when compared with GPS-R, we conduct a comparison analysis of the reflection distributions for these two cases at the GPS L1 and L2 frequencies in terms of the spatial and temporal characteristics in this section.  
While the signals from the different GNSS systems at their own operating frequencies will result in different beamwidths for the same antenna gain, the GPS L1 (1575.42 MHz) and L2 (1227.60 MHz) frequencies are the representative GNSS frequencies that are shown in Table 4. The value of the GPS L1 frequency is similar to that of the BDS B1 and GLONASS L1 frequencies. Additionally, GPS L1 has the same frequency band as Galileo L1. The value of the GPS L2 frequency is similar to the frequencies of GPS L5, BDS B2 and B3, GLONASS L2, and Galileo E5b and E5a. Therefore, only the GPS L1 and L2 signals, which have different beamwidths, are used to analyze the Earth's surface reflection distributions in this research.
# Challenge-Response Pair Mechanisms and Multi-Factor Authentication Schemes to Protect Private Keys
## 5 Discussion: Recovery Protocols in Real-Life Implementation
### Secure Key Recovery When the Token Is Defective or Lost  
Above, in Section 2.4, we briefly present how a Keystore corporation can offer a backup service to a user when a token is lost, stolen, or broken. We suggest that the Keystore can keep the reference table CT-T after the enrollment cycle of the token in support of the recovery process. In the event of a loss, the Keystore can transmit CT-T to the user  
Figure 14: Average latency for key operations. The two longest operations are the generation of the reference table CT-Bio from the server during the enrollment cycle, as well as the generation of the reference table CT-Token from the client device during normal operation. All error correcting and cryptographic schemes are below one second.  
Figure 13: RBC time vs. key error for different fragmentation levels. This graph shows that a fragmentation of 8 is an excellent tradeoff. The recovery times stay well below one second in the range of interest.  
though the unsecure network; the table thereby directly replaces the token to retrieve the ephemeral key K, and therefore the private key Sk. The risks associated with this process are quite low, as discussed below:  
* One possible vector of attack could start with an insider or a side-channel analysis able to intercept the table CT-T, and the password needed during challenge generation. The first line of defense against such an attack is the one-way-ness of the CRP mechanism generating CT-T from the token. The 256 \(\times\) 256 positions are randomly located in the SRAM, which contains one million cells, so the number of possible combinations to generate the table is staggering: \(\left(\frac{1M}{256\times 256}\right)\). It is highly unlikely that knowledge of the table could result in disclosure of RN\({}_{1}\). Without RN\({}_{1}\), the opponent cannot find the reference table CT-Bio from the biometric image, or CT-VT from the virtual token, making the uncovering of the combined reference table CT extremely hard. In addition, knowledge of RN\({}_{2}\) is also needed in the multi-layered MFA process.
* Another vector of attack could be taking physical control of the terminal device, and asking the Keystore to transmit CT-T. This could be a formidable attack, if the opponent also had access to all other factors of authentication. It is therefore recommended to incorporate additional protocols between the Keystore and the terminal device to protect the transmission of CT-T, such as the transmission of a code to a separate route such as email or SMS. In this second case, the token does not protect the terminal device; however, all other layers of protection remain in place. The MFA protocols were designed to keep an acceptable protection when only one factor of authentication is compromised; knowledge of CT-T is not enough to disclose CT, or therefore the ephemeral key.  
After the recovery cycle, a new enrollment cycle, with a new token, should be scheduled between the Keystore and the user.
# GRACE/GFO and Swarm Observation Analysis of the 2023-2024 Extreme Drought in the Amazon River Basin
## 3 Data and Methods
### Data
#### 3.1.7 ERA5 Data  
ERA5 is the fifth-generation global climate reanalysis dataset released by the European Centre for Medium-Range Weather Forecasts, and it is one of the most widely used reanalysis products worldwide. Built on the latest version of ECMWF's Integrated Forecasting System, it integrates massive global observational data (including satellite, ground stations, radiosondes, radars, etc.). Through four-dimensional variational assimilation technology, it achieves the optimal combination of observations and models, significantly improving the spatiotemporal consistency and accuracy of the data.  
In our study, the monthly 0.5\({}^{\circ}\)\(\times\) 0.5\({}^{\circ}\) vertical velocity (VV), specific humidity, u-wind and v-wind grid data were used to analyze atmospheric movement and water vapor transport during the drought. VV anomalies were obtained by subtracting the corresponding climatological mean value from the 30-year-based VV data.  
The datasets in our study are listed in Table 1.
## 2 Materials and Methods
### Surface Characterization
#### 2.3.3 X-ray Photoelectron Spectroscopy (XPS)  
XPS spectra were acquired using an Axis Supra DLD electron spectrometer (Kratos Analytical Ltd., Mandhester, UK) with a monochromatic Al K\(\alpha\) source (1486.6 eV). Survey- and core-level spectra of O 1s, N 1s, C 1s, Ti 2p and Si 2p were collected by applying 15 kV and 10 mA for the survey spectra and core-level spectra, respectively, and 15 kV and 15 mA for the highly resolved measured C 1s peaks. All XPS measurements were collected with a 250 \(\upmu\)m spot size, using a charge neutralizer during acquisition. Data processing were carried out using CasaXPS software, version 2.3.22 PR1.0 (Casa Software, Ltd., Teingmouth, UK). Curve fitting of the high-resolution C 1s spectra was also carried out using CasaXPS software. The line shape used was a Gaussian-Lorentzian (GL 30) function with a Shirley background. Due to sample charging, the binding energy scale was corrected for all samples by setting the C 1s binding energy to 285.0 eV. Concentrations were provided in atomic percent (at.%). A depth profile was generated by alternating cycles of spectral acquisition of the sample surface, followed by 10 keV Ar\({}_{1000+}\) bombardment of the sample surface. The beam was rastered over an area of 1.5 \(\times\) 1.5 mm\({}^{2}\).
# Plant-Based Fish Analogs--A Review
## 4 Technologies Used for Plant-Based Fish and Meat Analogs Production
### Texturization of Vegetable Protein (TVP)  
One method of producing meat- and fish-like products is extruding cooking plant materials for texturing fibrous substitutes for animal products. Textured vegetable proteins (TVP) are products used as substitutes for beef, poultry, or fish, which resemble these products not only in appearance but also in structure, color, and taste. They are available as powder, granules, or cubes [108]. Extrusion cooking is a popular food processing technique carried out at high temperatures for a short time. It is used to make fiber-rich products. This is how moistened, starchy, and protein-rich raw materials are plasticized and cooked in a tube by combining moisture, pressure, temperature, and mechanical shear through chemical reactions [18, 109]. Textured proteins can be obtained by two methods of extrusion--wet and dry. Extrusion with a feed moisture content below 40% is called low-moisture extrusion (LME), while extrusion performed with a feed moisture content above 40% is considered high-moisture extrusion (HME). The products obtained in the LME technology are characterized by low sensory acceptability and are not used in the production of fish analogs. HME makes it possible to obtain unexpanded fiber products that mimic the texture and taste of meat products [7, 110].  
Textured vegetable proteins find use in the production of nutritionally balanced or fortified products, as well as dietary products and animal product substitutes [109]. They are mainly made of skimmed soy flakes or soy flour. TVP contains very little fat, cholesterol, and a minimal amount of carbohydrates while being high in protein and fiber and, therefore, rich in amino acids. Textured soy protein is the most common, although textured wheat protein is also available [108]. However, soy protein use is limited due to the negative perception of soy products by consumers related to potential health hazards [111]. Therefore, the production of TVP also uses unconventional raw materials such as mucuna bean flour, faba bean, cotton, corn, pea and lupine, lima bean and African oil bean seed, oat protein, hemp, and lentils [7, 109, 110].
## 3 Description of MSIMP
### MSIMP Mathematical Modeling
The evaluation set is a key component in MSIMP for assessing the quality of mission planning schemes. It establishes a series of evaluation metrics to measure the effectiveness of mission execution, providing a comprehensive assessment of the feasibility and stability of the MSIMP model. Key metrics include task benefit, task allocation rate, area coverage, and response time. Task benefit evaluates the value and effectiveness of each mission, while task allocation rate reflects the rationality and balance in the distribution of satellite resources across tasks. Area coverage assesses the completeness and accuracy of imaging over the target area, and response time measures the efficiency from the submission of task requests to the completion of the mission. These evaluation indicators assist in optimizing the mission planning scheme, ensuring efficient resource utilization while meeting user requirements [48, 49, 50, 51]. The constraints in MSIMP are divided into two categories: satellite constraints and target task constraints. Satellite constraints include limits on observation quantity, payload capacity, side swing angle, and transition time, ensuring the stability of satellite operations and the efficiency of mission execution. Target task constraints involve uniqueness, task urgency, visible time window, and adjacent task time window constraints, ensuring a reasonable prioritization and sequence of task execution. These constraints guarantee the operability and rationality of the satellite mission planning process, enabling the effective implementation of multi-satellite imaging mission plans in complex real-world environments.