esa-sceva/satcom-chunk-collection huggingface dataset:
# Privacy-Preserving Overgrid: Secure Data Collection for the Smart Grid
## 3 The Overgrid Concept
### Architecture Overview  
As shown in Figure 1, Overgrid is a _virtual community_ of buildings participating in a distributed load control program, by means of an overlay P2P network where each node is a peer in the network. Here, for distributed load control program, we mean the possibility to adapt the aggregated power demand of all the nodes belonging to the Overgrid, in order to satisfy a dynamic power constraint provided by the Distribution System Operator (DSO) without the usage of a central server. Once the logical aggregation is defined and the P2P network is created, the Overgrid is operated as a generic microgrid, collecting the power consumption characteristics of each peer, distributing the DSO requests to modulate the electrical load and implementing the load control (on the individual peers), according to the distributed Demand-Response (DR) paradigm.  
Regarding the physical communication network between nodes, we assume that each Overgrid node is equipped with an Internet connection (towards other nodes) as well as a local connection (through WiFi, ZigBee, power line, etc.) for controlling appliances, smart plugs, storage, and production systems. Over this physical connection, the nodes in Overgrid form an unstructured P2P overlay based on Gossip protocols, a commonly used P2P paradigm allowing fault tolerant and scalable information diffusion across the network, totally decentralized and with low network overhead [27]. Gossiping protocols exploit periodic exchange of messages between nodes. The scalability comes from the fact that each node is in communication with a subset of other nodes (typically much smaller than the entire size of the network), which represents the neighbors of the node. Periodically, each node selects another node from its neighbors and exchanges messages containing the local view of some network parameters. Thanks to such a periodic exchange of messages, each node independently carries out a plurality of distributed functions to maintain the P2P overlay structure, distribute information to its neighbors, aggregate data, and operate the DR control, as detailed in [1].  
Once a decision on power reduction is taken by a node, a local energy management system is used to map such a decision into a specific control action on the building flexible loads, e.g., tuning of the temperature on the heating/cooling systems, switching off smart appliances, etc., also taking into account the preferences of the users. For example, Figure 1 shows the local energy management system composed of a local server, as well as an interface for defining the load control policies desired by the user by means of a common HTTP protocol. The implementation of the fine-grained local control and the technologies to be used are out of the scope of this paper.
# Leveraging Blockchain and Consignment Contracts to Optimize Food Supply Chains Under Uncertainty
## 6 Numerical Illustration
### Analysis of Retail Price on System Profitability with Managerial Insights
#### 6.4.2 Impact of Hassle Cost and Privacy Concern  
According to the theoretical model, consumer demand is only affected by the hassle cost in non-blockchain adoption. The privacy concern is incurred in blockchain adoption only. Hassle costs refer to the non-financial impediments or inconveniences that individuals encounter during the acquisition of goods or services, including factors such as time expenditure, physical effort, or the intricacies associated with the purchasing procedure. Thus, increase in hassle cost can directly impact consumer behavior. This study shows a linear relationship between demand and the hassle cost. Figures 14 and 15 indicate that, along with demand, the total system profit is also affected by this cost and a sharp decline in profitability is observed in both TS and CP. However, the manufacturer receives more profit than the retailer in both cases and the rate of decrease in the profit percentage is the same as the change in the hassle cost.  
A similar scenario happens for the consumer's privacy concern when the blockchain system is implemented by the company. Many research studies show that while providing a multitude of advantages, including transparency and security, blockchain technology concurrently engenders considerable privacy issues that may adversely affect clientele. Increased privacy concern increases public concern, which eventually decreases the demand  
Figure 14: Graphical representation of profit vs. hassle cost for TS without blockchain.  
Figure 15: Graphical representation of profit vs. hassle cost for CP without blockchain.  
rate. However, if the hassle cost and privacy concern are compared then both may affect consumer behavior equally. The influence of these two parameters depends on \(\beta\), \(\gamma\), \(h_{c}\), and \(a_{d}\). For the sake of convenience, if we consider the same values of \(h_{c}\) and \(a_{d}\), then two scenarios can occur. If \(\beta>\gamma\), then the demand as well as the profitability of the supply chain will be greater for blockchain adoption (Table 1).
## 1 Introduction  
The astronomers and the general population have been focusing on exoplanet detection (Figure 1).  
Figure 1: Star-planet system in \(x^{\prime}\)-, \(y^{\prime}\)- coordinate system, viewed from the rotational shearing interferometer at the origin of coordinate system (\(x\),\(y\),\(z\)) on or near the Earth. The star and the planet may be modeled as point sources with an elevation-angle, \(\theta\) (measured from the negative optical axis), and an azimuth-angle, \(\varphi\), with respect to the \(x^{\prime}\)- axis. The planet quantities have a subscript \(P\), those of the star have \(S\). The star coordinates correspond to the alignment error. The planet coordinates are unknown because it is invisible.  
The human-navigated robotic vehicles and mostly autonomous interplanetary satellites visited or flew by all planets in our solar system. More than 4000 planets outside the solar system in various stages of planetary evolution have been reported so far [1]. The astronomers have tried to understand the formation and the evolution of the solar systems. The futurists are interested in finding a suitable habitat for the human colonization when the Earth's resources can no longer support humanity. The majority of planet discoveries report on so-called Super Earths, cold planets orbiting a large, red giant star with a diameter of up to 1 AU, most of them a hundred light-years away.  
Possibly due to the use of instruments that the researchers employ, most of the reported exoplanets orbit red giant stars that would have gobbled up an Earth-like planet during the star evolution. These planets are also far away so there is little possibility that humanity could develop any realistic plans to colonize them. The pragmatic interest lies in the search for the nearby Earth-like planets that are characterized by moderate temperatures, solid ground, oxygen in the atmosphere, and presence of water for carbon-based life.  
The overwhelming majority of planets have been discovered by indirect techniques, among them transit light curves, radial velocity, and gravitational microlensing [2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26]. These techniques sense the effect of the planet on the star-emitted radiation. They measure variations in the star radiation and deduce the planet presence using statistical techniques and probability considerations. Our Sun also exhibits short-term and long-term variations in its emission. An example of the latter might be the time dependence of the solar magnetic domains and the consequent 24-year solar emission cycle. An example of the former might be prominences and expulsions of charged particles that extend up to the Earth, producing time-dependent, visible northern lights. An emission variability may be produced by similar processes or yet unknown phenomena in and around a distant star.
# Noise Cancellation Method for Mud Pulse Telemetry Based on Discrete Fourier Transform
## 2 Methods
### Traditional Pump Noise Cancellation Method in Time Domain  
The traditional method for cancelling mud pump noise is explained below. Mud pumps are large positive displacement pumps that generate flow by repeatedly moving a piston back and forth within a cylinder while simultaneously opening and closing the intake and exhaust valves [29]. As a result, the noise generated by the mud pump tends to show a certain pattern of periodicity [30; 31]. Consequently, a typical drilling mud pressure pattern, referred to as the standard pump signature, can be obtained by averaging pump signatures over multiple pump cycles [32]. Specifically, the acquisition of the standard pump signature is better accomplished in the absence of the information signal to avoid its impact on the mud pressure. When the MWD data signal is provided, the mud pump cycles are tracked using a pump stroke signal such that the pressure caused by the pump can be subtracted from the received signal in the time domain to provide the intact information signal [33; 34; 35].  
Figure 3 illustrates the noise cancellation procedure with the standard pump signature.
This paper categorizes visual-marker-based AR applications as \"marker AR\" and the associated virtual object manipulation methods as \"marker methods.\" \"Markerless AR\" will be used to refer to newer depth-sensing AR applications that are capable of tracking elements in the physical environment without visual markers, and the corresponding virtual object manipulation methods will be referred to as \"markerless methods.\"  
While marker methods have been well examined (e.g., [6; 7; 12; 13; 14; 15; 16]), there is currently a lack of study on markerless methods due to the relative novelty of the associated capable devices. Although marker and markerless AR differ only by a seemingly simple marker-tracking requirement, the implications on virtual object manipulation methods and the resulting AR applications can be substantial.  
The understanding of issues concerning markerless methods is an important first step in realizing the potential of markerless AR. This paper presents our approach to this research opportunity and the corresponding results. Our study examines the ramifications of eliminating the marker-tracking requirement, articulates the corresponding impacts, designs new test cases in response to these impacts, and re-evaluates existing marker methods in a markerless AR setting. Our results indicate that many of the results from marker AR studies are valid for markerless AR, although specific applicability depends on the size of the virtual object being manipulated.  
This paper begins with a survey of existing marker methods and explores the implications of removing the visual marker requirement for handheld AR systems. The sections that follow describe the choice of the marker methods for testing, the test suite implementation, and the test cases explored. The details of user testing and results are then presented, with a discussion of implications concluding the paper.
# VHF Omnidirectional Range (VOR) Experimental Positioning for Stratospheric Vehicles
## 5 Conclusions  
The data from the STRATONAV Experiment, launched in 2016 on a BEXUS stratospheric balloon from the Esrange Space Center in Kiruna, Sweden, have been reprocessed in order to achieve positioning through the intersection of multiple VOR radials. The experiment data collection was made possible through two separate receivers: a commercial receiver able to decode a radial at a time and a SDR recording the entire VOR band spectrum, therefore able to acquire all the VOR signals simultaneously.  
The positioning accuracy reached with the re-processing of the VOR data amounts 5.7 km of mean error and 3.29 km of standard deviation, which can be profiting from a limited amount of data due to the single radial data collection strategy, and 4.04 km and2.76 km of standard deviation for the SDR. The results are acceptable to consider the system a potential, low-cost back-up for high altitude GNSS receivers on stratospheric airships. From the STRATONAV results, further experiments have been started for stratospheric balloons: TARDIS had the aim of achieving real-time positioning and attitude determination through SDRs, while STRAINS uses the same technology for testing long baseline TDOA with stratospheric balloons in the perspective of future suborbital and satellite experimentation.  
Conceptualization, P.M.; methodology, P.M. and L.F.; software, P.M. and L.F.; investigation, P.M. and L.F.; writing--original draft preparation, P.M. and L.F.; writing--review and editing, P.M.; visualization, L.F.; supervision, F.P. and F.S. All authors have read and agreed to the published version of the manuscript.  
The STRATONAV experiment development received funding and support by the following companies: Eggecelerate, Mediasoft, MEGATRON Sensors, and Italian Amateur Radio Association (ARI)-Rome.  
Data sharing not applicable.  
Acknowledgments:STRATONAV project was part of the REXUS/BEXUS Programme. The REXUS/BEXUS programme is realized under a bilateral Agency Agreement between the German Aerospace Center (DLR) and the Swedish National Space Agency (SNSA). The Swedish share of the payload has been made available to students from other European countries through the collaboration with the European Space Agency (ESA). Experts from DLR, SSC, ZARM and ESA provide technical support to the student teams throughout the project. EuroLaunch, the cooperation between the Esrange Space Center of SSC and the Mobile Rocket Base (MORABA) of DLR, is responsible for the campaign management and operations of the launch vehicles. The publication of this manuscript is provided by the Italian Space Agency in the framework of the Accordo Attuativo ASI 2020-30-HH.0--IKUNS3-SIMBA for the future implementation of the developed radio-frequency technologies on-board nano-satellites.  
The authors declare no conflict of interest.
## 3 Result Analysis
### Diagnostic Performance of the Proposed TL-Based Method  
To validate the performance of the proposed TL-based method, the available data are divided into four different working conditions (WC), denoted WC 1, 2, 3, and 4 (described in Table 2). These datasets contain different speeds and loads, but the same type of health condition. The rpm invariance of this approach is validated by examining four separate scenarios. In the first scenario, WC 1 is used for training the network and saves the knowledge, and WC 2, 3, and 4 use that learning to perform the classification tests. From WC 2, 3, and 4, 10% of the data are used for adjusting the network to use the prior knowledge. In the second scenario, WC 2 is used for gathering the knowledge, and WC 2, 3, and 4 are used for TL-based testing. In the same manner, in Scenario 3, WC 3 is used for knowledge gathering, and in Scenario 4, WC 4 is used. The corresponding other working conditions are used for testing and classification. In each scenario, one dataset is known to the network, and the TL makes the later learning faster and more efficient, and achieves better accuracy. These tests validate the proposed approach. Table 3 lists the details of the diagnostic performance of the proposed approach.  
Figure 7: Vibration images based on DOST for different health conditions. (**a**) HC (Healthy Condition), (**b**) IRF (Inner Race Fault), (**c**) BF (Ball Fault), (**d**) ORF (Outer Race Fault), and (**f**) ORF at opposite position.  
To evaluate the performance of the proposed approach, the same experiment is also conducted with different amounts of training data. In this study, 80% of the training data are considered from the source dataset for each scenario (Table 2). With different percentages of training data, the overall classification accuracy varies as provided in Table 4. Table 4 clearly shows that the best performance is achieved when using 80% of the training data from the target dataset for the different scenarios.  
In the Methodology section, Table 1 describes the proposed neural network architecture for TL. The table also shows which layers or stages are transferred to the target dataset for different scenarios to evaluate the performance. There are four stages in the network (Table 1), and the first three are transferred to perform TL. To evaluate the network's performance, the number of stages is varied for transfer. In this study, 80% of data are used for training and the number of learning stages is only changed to evaluate the performance. Table 5 gives the overall performance results. As shown in Table 5, the proposed approach performs the best when Stages 1 to 3 (see Table 1) from the network are transferred to the target task.
## 3 Data Processing
### Ship Classification
#### 3.4.2 Fuzzy logic processing
\begin{table}
\begin{tabular}{l c c c c} \hline
**Category** & \(S_{\text{RCS}}\) & \(M_{\text{RCS}}\) & \(B_{\text{RCS}}\) & **Length [m]** & **Breadth [m]** \\ \hline Oil Tanker & High & Low & Low & 300 & 45 \\ Chemical & High & Low & Medium & 200 & 35 \\ Coaster & High & Medium & Low & 100 & 25 \\ Goods Cargo & High & Low & Medium & 150 & 25 \\ Gas Cargo & High & High & Low & 200 & 35 \\ Bulk & High & Medium & Low & 200 & 35 \\ Container & High & High & High & 225 & 45 \\ Car Ferry & Medium & High & Low & 150 & 25 \\ Fishing vessel & Medium & High & Low & 90 & 25 \\ Small targets & Low & Medium & Low & 40 & 10 \\ \hline \end{tabular}
\end{table} 
Table 1: Reference categories with the grades expected for the three normalized RCS values. Figure 5: Illustrative description of ship classification without taking fuzzy logic processing into account. With this information, the evaluation of the two previous rules results on:  
* **Rule 1:** 0.9 AND 0.65 AND 0.65 THEN **0.65**
* **Rule 2:** 0 OR 0 OR 0 THEN **0**  
With this information, the area filled in both true and false grades of the membership function of the Oil Tanker category is the one shown in Figure 6. As observed, the final likelihood of the input signature to belong to the Oil Tanker category is 0.8. With the application of this process for all the defined categories, a set of chance values are obtained, which bases the classification decision.
# Experimental Study on Small-Strain Shear Modulus of Unsaturated Sility-Fine Sand
## 2 BE-RC Combined Test Device  
### Improvement of Device Pedestal and Top Cap  
To control the matrix suction in a soil specimen, the first task is to modify the original Stokoe RC pedestal. A ceramic plate with an air entry value of 500 kPa was embedded in the center of the pedestal, thus, allowing a high level of matrix suction to be applied to a specimen using the axis translation technique for unsaturated soil. A limber hole and circular grooves were set below the ceramic plate to ensure a smooth water flow. The area where the ceramic plate and the pedestal connected was bonded with epoxy resin and cementation was completed at room temperature conditions for 24 h. Two cylindrical holes were set in the center of the pedestal and the top cap to install the bending element-extension element (BE-EE) probes. During the installation process, to improve the waterproof performance, rubber rings were added and silicone grease was applied to the side walls of the BE-EE probes, which prevented water from entering and eroding the data lines connecting the BE-EE probes under high-pressure conditions. Figure 1 shows the improved RC pedestal and top cap. Figure 2 shows the structure diagram of the improved BE-RC pedestal.  
Based on the modified RC pedestal and top cap, as shown in Figure 1, a test system combining a BE and RC was created. This system can allow the dynamic shear modulus of a soil specimen to be continuously tested in full range of small strains (10\({}^{-6}\)-10\({}^{-3}\)) under the dehumidification path by controlling the matrix suction.
## 3 Empirical Analysis
### Topological Properties of the CATN
#### 3.2.3 Temporal Property of Average Shortest Path  
The average path length of the aviation network can serve as a measure of the convenience of air travel for passengers. From a passenger's viewpoint, it is often impractical to take two flights within an hour. To evaluate this feature, the authors set the temporal window \(\omega\) as one year. In the CATN network with a time window of one year, the shortest flight paths are summarized in Table 2. In summary, the average path length in the CATN is 1.97, suggesting that the majority of cities were accessible by changing two or fewer flights. The analysis revealed that 89.75% of city pairs could be reached either through direct flights or with just one flight change.
###### Abstract  
Background: This study aimed to adapt the Spanish version of the Assessment of Stress in Nursing Students (ASNS) (shorter form) instrument for Spanish podiatry students, labeling the new tool as the Spanish version of Assessment of Stress in Podiatry Students (ASPS). The adaptation for reliability and repeatability included performing the transcultural adaptation process and examining the repeatability and reliability of ASPS when used in a different language. Methods: An internationally recommended translation procedure was used to adapt transculturally this tool. The instrument's test-retest reliability was evaluated in two sessions that were 10 days apart. Results: After considering each domain's total score, the reliability and internal consistency were analyzed with [PERSON]'s \(\alpha\) and intraclass correlation coefficient for a 95% confidence interval. Good internal consistency was reported according to total score (\(\alpha\) = 0.8626) and each one of the six domains: (1) the practical activities performance domain showed a [PERSON]'s \(\alpha\) of 0.8684; (2) professional communication domain, \(\alpha\) = 0.8765; (3) time management domain, \(\alpha\) = 0.8832; (4) environment domain, \(\alpha\) = 0.8974; (5) professional education domain, \(\alpha\) =0.873; and (6) theoretical activity domain, \(\alpha\) = 0.8787. Test-retest reliability, by paired test of Wilcoxon, was not significant, showing that there were not differences between domain scores (\(p\) \(\geq\) 0.05). Lastly, visual distributions of Bland and Altman plots did not provide differences between domains and total scores. Conclusions: The Spanish version of the ASPS showed good repeatability, reliability and acceptability to measure stress parameters for podiatry students.  
stress; students; podiatry; psychometrics; reliability studies