esa-sceva/satcom-chunk-collection huggingface dataset:
# Cluster-Based Data Aggregation in Flying Sensor Networks Enabled Internet of Things
## 3 Flying Sensor Network Cluster Optimization
### Clustering Setup  
The HBA is applied in the cluster setup phase to determine the optimal CHs [37]. The CH selection is based on the HBA to form a balanced cluster. When selecting CHs, the UAV mobility and neighbor criteria are considered to minimize re-clustering. In FSNet, once CHs are selected, they broadcast a message containing ID, position, and status. All UAVs in CH range will receive broadcast messages and join the cluster. Once UAVs join a cluster, they become CMs and share information with CH. If a UAV receives membership messages from multiple CH, joining will be based on the distance between the UAV and CH. If the distance is the same, the random UAV-CH selection mechanism will take place. The working of the cluster setup phase is shown in Algorithm 1 below. Once the cluster is formed, the data-aggregation-and-communication phase is initiated to transmit the data to the BS.  
```
1 Procedure CH-Selection-Multi-UAVs (MUAVs)(0)
2 Input : Swarm of UAVs\(SW_{UAV}\), UAV nectar \([u_{UAV}]\), and cluster \(C_{FSNet}\).
3 Output: UAVs-CH  call function calculate-UAVs-Nectar (\(n_{UAV}\))
4// v1 represents the number of nodes (UAVs) when there are \(n\) total UAVs in the network for\((v=1;v\leq C_{FSNet};v++)\) do
5// selection of UAVs-CH in a random way UAVs-CH\([\mathrm{v}]=\mathrm{functionRand}\ (SW_{UAV})\) end for while (highest-value\([=\) yes) do  for\((v1=1;v1\leq n_{UAV};v1=v1+1)\) do
6// the suitability of current selection is computed if (\(v1\) in UAVs-CH) then
7 Fitness Value \(FValue_{UAV}=FValue_{UAV}+1(SW_{UAV}[u]+AFV_{UAV})\)
8// Average fitness value \(AFV_{UAV}\) end if
9 end for if (\(FValue_{UAV}<PFValue_{UAV}\)) then
10//PFValue_{UAV} is the suitable value in the existing solution swap \(FValue_{UAV}\)
11 end if if (UAVs-CH-optimum! = yes) then  while\((\mathrm{empb!}=0)\) do // Employed bee (empb)
12// visiting of bees employed till empty, where \(\alpha_{ij}\) is UAV affiliation with the current round while \(y\) is the neighborhood size \(UAV_{j}(x+1)=UAV_{j}(x)+\alpha_{ij}*y\)
13// selection of different UAVs from fellow citizen
```  
**Algorithm 1**Pseudo Code of UAVs Enabled CH Selection.
## 2 Materials and Methods
### Statistical Analyses  
Standard statistical methods were used for the calculation of the means and standard deviations (SD). The normality of the data was verified using the Shapiro-Wilk test. Student's t-test was used to determine differences between the time points (i.e., T1 vs. T0 and T2 vs. T1). The significance level was set at \(p<0.05\). The effect size was calculated to estimate the magnitude of the differences between the time points using Hedge's g and interpreted as large (g \(>\) 0.80), moderate (g \(>\) 0.50), or small (g \(>\) 0.20) [45]. The sensitivity of the IKE test was examined by comparing the changes generated in this test against the repeatability of the protocol itself (using the standard error of measurement, SEM). This variation was recently described for both the dominant (SEM = 0.26 N/kg) and non-dominant legs (SEM = 15 N/kg) in older adults with characteristics similar to those included in the current study (age 87.0 years, BMI 28.5, SPPB 5.4 points) [22]. The statistical calculations were performed using a custom Microsoft Excel spreadsheet and statistical software SPSS version 22 (IBM Corp., Armonk, NY, USA). The figures were designed using GraphPad Prism software version 6.0 (GraphPad Software Inc., La Jolla, CA, USA).
# Hybrid Satellite-Terrestrial Networks toward 6G: Key Technologies and Open Issues
## 4 HSTN Applications
### Aerial Communication  
An airborne network typically consists of balloons, airplanes, and/or UAVs, with aircraft having a critical need for broadband access to support passengers' urgent communication requirements. However, current in-flight communication, such as Wi-Fi services, is rather capacity-limited, failing to satisfy the broadband communication demands of passengers.  
Because of its broad coverage, an HSTN can provide continuous broadband service to passengers throughout flights, connecting the air with the ground. GEO or MEO satellites can be used to minimize frequent satellite handovers, while LEO satellites can be used to decrease communication latency. Additionally, the HSTN can be used to communicate with balloons and UAVs, which can be used for regional coverage, environmental monitoring, and border surveillance.  
Some possible HSTN application cases were explored in this section. We have given a general overview of how HSTNs can expand coverage on land, in the air, and at sea. The importance of HSTNs in enhancing maritime coverage was outlined, and their potential for providing coverage over difficult terrain and sparsely populated areas was highlighted.
# Topological Interference Management for K-User Downlink Massive MIMO Relay Network Channel
###### Abstract  
In this paper, we study the emergence of topological interference alignment and the characterizing features of a multi-user broadcast interference relay channel. We propose an alternative transmission strategy named the relay space-time interference alignment (R-STIA) technique, in which a \(K\)-user multiple-input-multiple-output (MIMO) interference channel has massive antennas at the transmitter and relay. Severe interference from unknown transmitters affects the downlink relay network channel and degrades the system performance. An additional (unintended) receiver is introduced in the proposed R-STIA technique to overcome the above problem, since it has the ability to decode the desired signals for the intended receiver by considering cooperation between the receivers. The additional receiver also helps in recovering and reconstructing the interference signals with limited channel state information at the relay (CSIR). The Alamouti space-time transmission technique and minimum mean square error (MMSE) linear precoder are also used in the proposed scheme to detect the presence of interference signals. Numerical results show that the proposed R-STIA technique achieves a better performance in terms of the bit error rate (BER) and sum-rate compared to the existing broadcast channel schemes.  
Keywords:\(K\)-user MIMO relay channel; minimum mean square error (MMSE); interference alignment; limited CSIR knowledge +
Footnote †: journal: Sensors
# Haystack Fires in Australia: Causes and Considerations for Preventative Management
## 5 Monitoring of Agricultural Parameters
### Near-Infrared Sensors  
Finally, near-infrared sensors are a new technology often used in industrial and laboratory settings. The near-infrared spectrum contains strong absorption bands for hydrogen bonds which can be used to elucidate the water content in a solid material. This type of sensor emits near-infrared light at approximately 970 nm, which is absorbed by the tested materials' surface [68].  
The light reflected to the sensor is from dry matter, which is proportional to the moisture content in the material. This makes near-infrared a surface level measurement which requires a clear lens to maintain an acceptable state of calibration. The process is non-destructive and non-intrusive, which has enabled its widespread use on food processing lines. The largest influence on the reading is from variations in the sample temperature [82]. This method requires the most significant signal processing because many wavelengths must be monitored and compared. Some of the light is absorbed or transmitted, while the rest is reflected. Higher absorption will occur with a decrease in the amount of reflected light at higher moisture contents in the tested sample. The amount of reflected light at specific wavelengths, ranging from 200 to 2200 nm, can be used to determine the moisture content. The amount of light that is transmitted through a material is minimal.  
One limiting factor is that NIR light only penetrates the outer surface of the material tested and does not reflect the physical properties of the material underneath a sample's surface [69]. [PERSON] [69] conducted tests with two models of sensors, one in both the laboratory and the field, and the second only in the laboratory. The first sensor did not adequately estimate lucerne silage or wet maize silage moisture contents in either the laboratory (static test stand) or the field environments (mounted on a silage chopper). The second sensor was accurate in static laboratory testing, with 94% of the data for wet corn silage within \(\pm\)2% of the actual moisture content. However, subsequent field testing with a silage chopper showed that the accuracy within \(\pm\)2% decreased to 81% of all samples collected. No testing was conducted on either sensor with lucerne hay bales [69].
## 4 Use Case
### Case: Thrombosis in the Device  
Between 2008 and 2015, recurring cases of thrombosis in VADs were causes of hospital readmissions and patient deaths with implanted VADs [25; 26; 27]. The reported cases prompted a group of physicians to reflect on best practices for detecting and treating blood flow obstruction in patients with an implanted VAD [25]. Among the previously mentioned complications, thrombosis was chosen for the application of the method because, although it occurs infrequently, it has the potential to cause severe damage that can interfere with the VAD's ability to provide adequate blood flow to the patient, involving an elevated risk of death.  
The HVAD was implanted in patients. The device uses a centrifugal pump actuator. The inflow cannula is inserted into the left ventricle, while the outflow cannula directs blood flow to the aorta [15; 34]. Considering the potential risks associated with thrombus formation, it is essential to evaluate and establish a method for monitoring these events. Since such events may occur, it is crucial for the medical team to establish diagnostic guidelines and implement the necessary interventions. Therefore, a study is proposed to identify the risks associated with these events and the potential adverse processes that may follow.  
It was unnecessary to gather specialists for data collection since the secondary data represents the knowledge and expertise of a team of specialists and meet the needs outlined for this work. Next, the information established by the medical team as inputs for diagnosing blood flow obstruction, taken from [PERSON] et al. [25], is presented.  
1. Indirect measurement of blood flow (acquisition via device alarms).
2. Indirect measurement of electrical power consumption (acquisition via device alarms).
3. Direct measurement of pump vibration through acoustic analysis.
4. Imaging diagnostics through exams.
5. Assessment of clinical parameters through laboratory tests and medical evaluation.
6. Thrombosis within the pump can compromise blood flow in three ways: (1) pre-pump thrombosis. (2) intra-pump thrombosis. (3) post-pump thrombosis at the level of out-flow graft and aortic anastomosis.
## 1 Introduction  
The broad expansion of Information and Communications Technologies (ICT) and the pervasive deployment of interconnected networks, along with service-oriented architectures, that enable the composition and provision of interactive and personalized services, have introduced overarching challenges related to security, dependability, privacy, and trust. Not only should they have built-in privacy and security, but they should also enable and empower users to comprehend and make informed decisions on trustworthiness of information, services, and levels of security. As governments are moving away from inter-organizational modalities and put emphasis on a collaborative and service-oriented model, issues concerning data privacy, protection against misuse, consent, accountability, and assurance to (re)gain attention. Hence, it is essential for them to strike the right balance between the needs for privacy and openness.  
The deployment of privacy aware e-Government environments that allow for the provision of interoperable user-centric electronic services, while empowering users to retain control over their personal data, is largely acknowledged as a challenge in [1; 2; 3; 4]. The incorporation of privacy policy and privacy preferences documents, through well-defined XML schemas, is an approach that can assist towards establishing certain level of assurance on data privacy for both users and service providers (SP) [5; 6; 7]. Such deployment advances and simplifies the provision of electronic services, while allowing users to preserve, control, and modify their personal data privacy characteristics based on their inclinations and needs. Based on such an architecture, e-Government environments could expand their capabilities towards implementing services that meet citizen needs, promote further exploitation of electronic services to different user groups and, finally, (re)establish confidence in applications of e-Governments involving sensitive personal information.  
This paper addresses the formulation of coherent and accurate privacy policy documents, from service providers' perspective, while preserving compliance with underlying legal and regulatory framework. Through the exploitation of existing governmental hierarchies, a multitier approach is proposed able to support differ data needs and processing requests imposed by them. The inclusion of specific rules and referencing XML elements enables the formulation of light-weight documents that adhere to the imposed requirements.  
The rest of the paper is structured as follows. Section 2 presents an architecture that promotes the employment of privacy policies and privacy preferences in modern e-Government environments while Section 3 presents the proposed hierarchical approach. Section 4 introduces a use case that provides evidence about its usability and functionality, while Section 5 discusses similar approaches on e-Health environments. Finally, Section 6 concludes the paper providing directions for future work.
# Path Planning Based on Artificial Potential Field with an Enhanced Virtual Hill Algorithm
## 1 Introduction
However, there are issues such as the robot being unstable at the beginning of the learning process, results varying depending on the initial conditions, and high computational load. Additionally, in unknown environments, the robot's responsiveness is reduced until the learning process is completed, making immediate path planning difficult. On the other hand, the artificial potential field algorithm with a virtual hill used in this paper has the advantage of being able to avoid obstacles, escape local minima, and reach the destination without a learning process in unknown environments. In [32], a method of escaping from the local minimum using a virtual hill is introduced. The virtual hill generates extra force instead of attractive force to repel the robot from a local minimum. The virtual hill technique does not require prior information about space and obstacles, modeling [33] and learning [23; 24] processes for generating potential fields may be omitted, and a new local minimum is not created. It also has the advantage of being applicable to dynamic environments and being easy to implement. And in most cases, a robot can escape from the local minimum. This is an easy and safe way for a robot to move to a destination while avoiding obstacles in an unknown environment without being trapped in a new local minimum. The virtual hill technique is a method of moving along the outline of the obstacle that caused the local minimum. The robot determines which direction to follow among the left and right obstacles to drive as soon as it is trapped in the local minimum. Efficient and reliable path planning is possible if the robot selects the obstacle that leads to the shortest distance. In the previous study [32], the direction of movement was selected only in the relative positional relationship between the robot, the closest obstacle, and the destination without considering the shape of the path. As a result, the robot may go a long distance or choose a dead end. Therefore, there is a need to reduce errors in the selection of the direction of driving regardless of obstacle shape and to improve the efficiency of the robot's movement. This paper proposes 'the enhanced virtual hill' technique, a method of determining the driving direction that considers the shape of surrounding obstacles. At the moment the robot is trapped in a local minimum, the distance to obstacles is measured, and it is determined which of the two directions is the more open path. The driving efficiency of the robot can be improved by blocking closed-path driving in advance. Additionally, a dead-end algorithm is proposed that allows the robot to come back without going deep when it encounters a dead end. Through simulations, it is confirmed that the robot's moving distance is reduced when the proposed methods are applied.
# Numerical Simulation of Rock-Breaking Mechanism by Spherical Tooth Impact in Granite Formation
## 3 Results and Discussion
### Study on the Influencing Factors of Single-Tooth Broken Rock  
For the simulation analysis of rock fragmentation by single tungsten carbide buttons with diameters of 16 mm and 22 mm, the study first conducts an overall analysis of the specific energy of fragmentation to understand the rock-breaking efficiency under different drilling pressures and impact energies. Subsequently, an in-depth investigation is carried out on the vertical failure to explore the rock cracking behavior and fragmentation effects under various working conditions. Based on the analysis of vertical failure, further study is conducted on circumferential fragmentation to comprehensively understand the fragmentation characteristics of the single tungsten carbide button in different directions.
## 2 Piezolectric Harvesters (PEHs)
### Commercially Available Piezoelectric Elements  
Examples of commercially available piezoelectric elements that can be used to build low-power alternative sources of electrical energy are ABT-441-RC [29] and ABT-448-90-RC [30]. For them, the outer diameter is no larger than 35 mm, and the generated sinusoidal voltage on the electrodes in a resonance has maximum value for the amplitude. The equivalent internal electrode capacitance is approximately 20 nF \(\pm\) 30%. The natural resonant frequency is up to 3 kHz, and the equivalent resonant resistance is higher than 200 \(\Omega\). The operating temperature range of the piezoelectric elements is from \(-\)20 \({}^{\circ}\)C to \(+\)70 \({}^{\circ}\)C, and the parameters listed above are determined at a temperature of 25 \({}^{\circ}\)C. Based on laboratory experimental studies performed with ABT-441-RC at frequencies lower than the resonance frequency, the amplitude of the produced non-sinusoidal voltage (in the presence of higher harmonics) can have lower values, and the internal resistance reaches values of up to tens of kiloohms. Thus, the piezoelectric element can be considered more like a current source with internal resistance and capacitance, according to the equivalent circuit in Figure 3a. For ABT-448-90-RC, a third terminal has been added that can be used in a feedback circuit. In the generator mode of operation, this terminal can be left unconnected. To design electronic converters, it is essential to use equivalent electrical circuits in which the behavior of real devices is modeled with sufficient accuracy.  
Another frequently used group of low-power piezoelectric elements that convert mechanical vibrations or shocks into AC voltage are the PPA (Piezo Protection Advantage) generators of the Mide Technologies(r) company [31]. The PPA elements from Mide Technologies(r) (Wobum, MA, USA) are mounted in rectangular packages and are designed for cantilevers or fixed-beam configurations. Each of the products has a wide range of resonant frequencies from as low as 20 Hz up to 500 Hz. All elements will operate at virtually any frequency in actuation. In energy harvesting, they will need at least 2 Hz of motion to produce any electrical current. They are virtually unlimited in regard to higher frequencies. Moreover, they can generate a few mA of current at several volts of output voltage.
## 3 Results
### SFA-CHCl3 Extract Induced Apoptosis of HepG2 Cells  
The apoptotic induction of HepG2 cells using SFA-CHCl3 extract treatment was analyzed further by flow cytometry analysis (Figure 4A-D). The increase in SFA-CHCl3 extract treatment time caused a decrease in the live cell ratio. The ratio of cells suffering from apoptosis (including early apoptosis and late apoptosis) was increased from 1.27 \(\pm\) 0.23% (control group) to 22.90 \(\pm\) 0.76%, 34.90 \(\pm\) 1.41%, 43.17 \(\pm\) 0.67%, after 24 h, 48 h, and 72 h SFA-CHCl3 extract treatment, respectively. Moreover, HepG2 cells under SFA-CHCl3 extract treatment exhibited chromatin condensation and DNA fragmentation (Figure 4E). These results show that SFA-CHCl3 extract treatment could induce significant apoptosis in HepG2 cells.  
The expression of bax and bcl-2 was determined by real-time RT-PCR and Western blotting (Figure 5A,B). The results showed that bax expression in HepG2 cells under 24 h and 48 h of SFA-CHCl3 extract treatment was higher than HepG2 at 0 h treatment. In contrast, bcl-2 expression was reduced in HepG2 cells for 48 h of SFA-CHCl3 extract treatment, compared to other groups.  
Figure 4: The apoptosis analysis of HepG2 cells over time. (**A–D**) displayed the representative apoptosis map of HepG2 cells from control group, 24 h, 48 h, and 72 h of SFA-CHCl3 extract treatment, respectively (Q1 indicates necrotic cells, Q2 indicates the live cells, Q3 indicates the early apoptotic cells, and Q4 indicates the late apoptotic cells). (**E**) Nuclear morphology of HepG2 cells (White arrow indicates nuclear fragmentation; dotted arrow indicates chromatin condensation). Original magnification 400\(\times\).