esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Discussion
### Comparation with Study in Conventional Spaces and Small Spaces  
In our research, we observed that increasing illuminance from 150 lx to 200 lx did not significantly enhance participants' preference for the lighting environment; instead, there was a slight decline (the mean value decreased, although not significantly). This trend was particularly noticeable at color temperatures of 4000 K and 5000 K, with the preference for 150 lx being moderately satisfied. This finding aligns with two other investigations into lighting in small spaces. [PERSON] et al. [20] adapted [PERSON]'s concept of a pleasing zone based on semantic scale outcomes in a study of capsule hotels, where an illuminance of 300 lx was evaluated using a seven-point Likert scale and rated close to five points. Similarly, [PERSON] et al. 's study [21] on perception in small spaces identified an optimal illuminance level of 100 lx, which also approached a five-point rating on a seven-point Likert scale. Conversely, a comprehensive examination of lighting in traditional spaces revealed that an illuminance of 200 lx consistently scored below 50 points out of 100 [31]. This discrepancy may be attributed to differences in eye-level illumination. In standard spaces, with ceiling heights typically over 2 m, the distance from a seated person's eye level to the ceiling-mounted light source is at least 0.8 m. However, studies on lighting in small spaces often feature room heights of 1.2 m or less, placing the eye level approximately 30 cm from the ceiling light source. This proximity significantly alters the perception of brightness and can lead to a more intense experience of the light, which may explain why lower illuminance levels are often preferred in smaller spaces. The closer presence of the light source not only increases the direct illumination but also enhances the perceived brightness due to the reduced distance, potentially making higher illuminance levels feel overwhelming or less comfortable in confined environments. Furthermore, psychological factors may also play a crucial role in this preference. In smaller spaces, individuals may seek a cozier, more intimate atmosphere that is often associated with lower levels of light. This desire for a subdued ambiance can contrast sharply with the preference for brighter, more vibrant lighting in larger, more open spaces where activities requiring higher visibility may dominate. Thus, the context of the space and the associated psychological comfort levels significantly influence lighting preferences. The adaptation level theory suggests that human perception of lighting conditions is relative and can be influenced by previous exposure to light levels.
# Trellis Tone Modulation Multiple-Access for Peer Discovery in D2D Networks
## 2 System Model and Conventional FDMA-Based D2D Discovery
### Drawbacks of FDMA-Based Discovery  
The conventional FDMA-based discovery described in the preceding subsection is a combination of the frequency division multiple access and the contention-based multiple access. D2D discovery networks do not have a central scheduler such as an eNB, which exclusively allocates resources to UEs. Therefore, each UE must choose its own resource by itself.  
The major problem of the FDMA-based discovery is that two or more UEs are not able to select the same RB or transmit signals. This causes two serious limitations:  
1. Complexity and delay of discovery process: The FDMA-based discovery does not allow collision; each UE performs the dynamic collision avoidance by listening to signals of other UEs and selects a vacant RB. This operation prevents a UE from transmitting a discovery signal immediately,  
Figure 1: Timing diagram of repetitive LTE uplink frames including peer discovery time slot.  
thereby causing a delay. Even if each UE performs a collision avoidance operation, since it operates individually, collision can always occur and it must therefore perform the function of detecting a collision. If the discovery message recovery fails due to the collision, the reselection of a resource must follow, which again leads to a delay.
2. Increased discovery overhead: In FDMA-based discovery, a multi-user detection (MUD) scheme is required when discovery signals of multiple UEs are collided on the same RB. To conduct the MUD, a channel code and successive interference cancellation (SIC) technique are required [26]. The use of a channel code reduces the resource efficiency because of the overhead of parity bits. In addition, SIC is required pilots for channel estimation and resources for collision detection, which increase the discovery overhead.  
The above-mentioned problems need to be solved for more efficient D2D discovery. In this paper, we propose a new non-orthogonal multiple access using trellis tone modulation as a D2D discovery scheme. The proposed scheme enables the discovery to proceed smoothly even when multiple UEs participate in the discovery through the same resources.
# Performance Analysis of UAV-IRS Relay Multi-Hop FSO/THz Link
## 1 Introduction
However, the integration of UAVs as flexible relay nodes in this configuration remains unexplored. Building upon the aforementioned studies, it is observed that the majority of research concentrates on dual-hop and triple-hop configurations, often employing conventional RF/FSO hybrid systems. However, there is a notable absence of integration of THz technology with IRS-UAV systems as an alternative backup for FSO links. Additionally, while evaluating multi-hop IRS-assisted systems, the scholarly focus predominantly lies on deriving closed-form expressions for system outage probabilities. This indicates a gap in the literature, as there is a dearth of comprehensive assessments encompassing various dimensions of system performance. Furthermore, several studies have overlooked the influence of the number of IRS reflector units, a critical parameter for system performance. Addressing this oversight, the current study introduces a novel communication system architecture that involves mounting an IRS onto a UAV. This design facilitates the creation of an IRS-UAV assisted multi-hop FSO/THz communication system. The multi-hop relay approach employed by this system not only broadens the communication system's reach but also enhances the link quality by utilizing the THz band as a contingency for the FSO link. By implementing both hard-switching and soft-switching strategies, it amalgamates the strengths of both technologies to bolster communication quality. Moreover, the IRS-UAV support scheme augments system performance on multiple fronts, notably by amplifying the signal strength beyond that of conventional hybrid FSO/THz systems. Additionally, this study employs the decode-and-forward (DF) protocol and conducts a thorough evaluation of the system's performance. It specifically investigates the UAV-based IRS-assisted hybrid multi-hop FSO/THz link system, wherein the FSO link is subject to gamma-gamma fading and THz links have pointing issues and follow a distribution. The structure of the remainder of this paper is as follows: Section 2 delineates the system and channel models. Section 3 presents a detailed performance analysis of the hybrid multi-hop FSO/THz link system. Section 4 provides further numerical results. Section 5 offers concluding remarks.
## 3 Conductive Polymer Based Coating  
### Polyaniline (PANI)  
PANI is one of the earliest found conjugated conductive polymers, and its conductivity is between 5 and 10 S cm\({}^{-1}\). Polyaniline is a typical organic conductive polymer, and although the \(\pi\) electrons in its structure have the ability to delocalize, it is not a free electron. The conjugated structure in the molecule increases the \(\pi\) electron system; the electron delocalization is enhanced. When the conjugated structure reaches a large enough scale, the compound can provide free electrons, so as to be able to conduct electricity.  
Many studies on the mechanism and applications of polyaniline in metal corrosion prevention show that the corrosion prevention mechanism of polyaniline on metal mainly has several points (Figure 4): (1) [PERSON]'s [83] research on metal passivation theory found that doped polyaniline can catalyze itself and form a passivation film on the metal surface after oxidation by first reducing. In addition, polyaniline has a self-repairing effect. When the passivation film is damaged, polyaniline can repair the passive film and maintain its stable existence for a long time. (2) Shielding effect: it was found by electrochemical impedance spectroscopy (EIS) that when the thickness of electrochemical polymerized polyaniline coating was greater than 1 \(\upmu\)m, the polyaniline coating can completely separate the metal from the corrosion medium, significantly delaying the metal corrosion, which is the physical shielding effect of the polyaniline coating [84]. (3) Electric field protection of polyaniline will generate a special electric field at the metal interface. During corrosion, the direction of electron transmission is opposite to that of the electric field. The electric field force becomes an important factor preventing the movement of electrons from the metal to the oxidant. At this time, the metal surface is protected by the electric field [85]. In recent years, polyaniline has obtained more and more applications in the field of hydrogen energy due to its protective effect on metals. [PERSON] et al. [86] deposited a polyaniline layer of 2.5 \(\upmu\)m on the surface of 304 stainless steel, showing stable structural characteristics and good corrosion resistance. The adhesion characteristics of the polyaniline coating on the 304 stainless steel did not change significantly within 648 h, and the polarization current density was stable at 0.059 \(\upmu\)A cm\({}^{-2}\), which is significantly better than the original 304 stainless steel, revealing the great potential of polyaniline in the field of metal BP coating.  
Figure 4: **(a)** The concept of ennobling mechanism using PANI. **(b)** Corrosion protection of iron electrode coated with conductive polymer. Two mechanisms can be identified: (1) barrier protection of the PANI coating suppresses the active metal dissolution, and (2) ennobling effect due to the redox activity of the PANI which shifts the potential into a passive domain at higher potential values. **(c)** Schematic illustration for the chemical reactions of PANI for corrosion protection of iron through different mechanisms [87].
## A Pseudolite-Based Positioning System for Legacy GNSS Receivers  
**[PERSON] 1, [PERSON] 2, [PERSON] 3 and [PERSON] 1,*g**  
1 School of Mechanical and Aerospace Engineering and the Institute of Advanced Aerospace Technology, Seoul National University, Daehak-dong, Kwanak-gu, Seoul 151-744, Korea; E-Mail: [EMAIL_ADDRESS]  
2 Agency for Defense Development, The 3 rd R&D Institute-4, ADD, Yuseong P.O. Box 35-3, DAEJEON 305-600, Korea; E-Mail: [EMAIL_ADDRESS]  
3 Sensor System Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea; E-Mail: [EMAIL_ADDRESS]  
*Author to whom correspondence should be addressed; E-Mail: [EMAIL_ADDRESS]; Tel.: +82-2-880-1912; Fax: +82-2-888-2069.  
_Received: 2 December 2013; in revised form: 17 March 2014 / Accepted: 18 March 2014 / Published: 27 March 2014_  
**Abstract:** The ephemeris data format of legacy GPS receivers is improper for positioning stationary pseudolites on the ground. Therefore, to utilize pseudolites for navigation, GPS receivers must be modified so that they can handle the modified data formats of the pseudolites. Because of this problem, the practical use of pseudolites has so far been limited. This paper proposes a pseudolite-based positioning system that can be used with unmodified legacy GPS receivers. In the proposed system, pseudolites transmit simulated GPS signals. The signals use standard GPS ephemeris data format and contain ephemeris data of simulated GPS satellites, not those of pseudolites. The use of the standard format enables the GPS receiver to process pseudolite signals without any modification. However, the position output of the GPS receiver is not the correct position in this system, because there are additional signal delays from each pseudolite to the receiver. A post-calculation process was added to obtain the correct receiver position using GPS receiver output. This re-estimation is possible because it is based on known information about the simulated signals, pseudolites, and positioning process of the GPS receiver. Simulations using generated data and live GPS data are conducted for various geometries to verify the proposed system. The test results show that the proposed system provides the desired user position using pseudolite signals without requiring any modifications to the legacy GPSreceiver. In this initial study, a pseudolite-only indoor system was assumed. However, it can be expanded to a GPS-pseudolite system outdoors.  
Keywords:GPS; pseudolite; indoor navigation
# A Novel Dual Authenticated Encryption Scheme Suitable for Social Networking Services
## 2 Preliminaries
### Bilinear Pairing  
Let \(\mathbf{G}_{1}\) and \(\mathbf{G}_{2}\) be an additive and a multiplicative group of the same prime order \(q\), respectively. We utilize the symbol of \(e\) to denote a bilinear map, i.e., \(e\): \(\mathbf{G}_{1}\times\mathbf{G}_{1}\rightarrow\mathbf{G}_{2}\) and it has the following properties:  
(i) **Bilinearity:**  
\[e(A_{1}+B_{2},P)=e(A_{1},P)e(B_{2},P);\]  
\[e(P,A_{1}+A_{2})=e(P,A_{1})e(P,A_{2});\]  
(ii) **Non-degeneracy**: Let \(P\) be a generator of the group \(\mathbf{G}_{1}\). Then we say that \(e(P,P)\) would be a generator of the group \(\mathbf{G}_{2}\).  
(iii) **Computability:** For any \(A_{1}\), \(B_{2}\)\(\in\mathbf{G}_{1}\), there is an efficient algorithm to compute \(e(A_{1},B_{2})\).  
**Elliptic Curve Discrete Logarithm Problem; ECDLP**  
Given two points \(P\), \(Q\in{\bf G_{1}}^{2}\) where \(P\) is a base point and \(Q=aP\) for some integer \(a\in Z_{q}^{*}\), the ECDLP is to compute \(a\).  
**Elliptic Curve Discrete Logarithm (ECDL) Assumption**  
The advantage of every probabilistic polynomial-time (PPT) algorithm \({\cal A}\) to solve the ECDLP is negligible. More precisely, let \(D(k)\) be every positive polynomial with all sufficiently large \(k\). Then we can express the algorithm \({\cal A}\)'s probability to solve an ECDLP instance (\(P\), \(Q\)) as  
\[\Pr[{\cal A}(P,Q=aP)=a;a\gets Z_{q}^{*},P,Q\leftarrow{\bf G_{1}}^{2}] \leq 1/D(K).\]  
The probability is evaluated over the uniformly and independently chosen instance and over the random choices of \({\cal A}\).  
**Bilinear Diffie-Hellman Problem (BDHP)**  
Given four points \(P\), \(P_{1}\), \(P_{2}\), \(P_{3}\in{\bf G_{1}}^{4}\) where P is a base point, \(P_{1}=xP\), \(P_{2}=yP\) and \(P_{3}=zP\) for some integers \(x,y,z\in Z_{q}^{*}\), the BDHP is to compute \(e(P,P)^{xyz}\in{\bf G_{2}}\).  
**Bilinear Diffie-Hellman (BDH) Assumption**  
The advantage of every PPT algorithm \({\cal A}\) to solve the BDHP is negligible. More precisely, let \(D(k)\) be every positive polynomial with all sufficiently large \(k\). Then, we can express the algorithm \({\cal A}\)'s probability to solve a BDHP instance (\(P\), \(P_{1}\), \(P_{2}\), \(P_{3}\)) as  
\[\Pr[{\cal A}(P_{1}=xP,P_{1}=yP,P_{3}=zP)=e(P,P)^{abc};x,y,z\gets Z_{q}^{*},P,P_{1},P_{2},P_{3}\leftarrow{\bf G_{1}}^{4}]\leq 1/D(K).\]  
The probability is evaluated over the uniformly and independently chosen instance and over the random choices of \({\cal A}\).  
**3. Proposed DAE Scheme**  
We present the proposed construction of DAE scheme utilizing bilinear pairing groups. Initially, the participated parties and the definition of algorithms are stated below.
# A Simplified Free Vortex Wake Model of Wind Turbines for Axial Steady Conditions
## 2 Simplified Free Vortex Wake
### Blade Model  
The FVW model assumes that the flow field is incompressible and potential. Figure 2 shows the rotor body frame coordinates with the \(z\)-axis pointing downstream. The blade is modeled by the Weissinger-L model [19], which is a good compromise between the lifting line and the lifting surface models, as a series of straight constant-strength vortex segments lying along the blade quarter chord line. The control points are located at the 3/4-chord line at the center of each vortex segment. The wake vortices extend downstream from the 1/4-chord and form a series of horseshoe filaments. The trailing and shed vortices are modeled by the trailing and shed straight-line vortex filaments as shown in Figure 2.  
The blade root section corresponds to the boundary of the first blade element. The remaining boundary distribution along each blade is achieved using the following \"arc-cosine\" relationship:  
\[(\vec{r}_{b})_{i}=\frac{(r_{b})_{i}}{R}=\frac{2}{\pi}\text{arccos}\bigg{(}1- \frac{i-1}{N_{E}}\bigg{)} \tag{1}\]  
where \(N_{E}\) is the number of blade elements and \(i\) is the element boundary number (\(i=1\),..., \(N_{E}+1\)). Consequently, there are \(N_{E}\) element control points and (\(N_{E}+1\)) boundary points.  
Figure 2: Schematic of the blade model and the vortex wake model.  
The strength, \(\Gamma_{b}\), of each blade element is evaluated by the application of the Kutta-Joukowski theorem on the basis of airfoil data. The bound vorticity for the \(i\)th blade element is given by:  
\[(\Gamma_{b})_{i}=\frac{1}{2}W_{i}C_{l}c_{i} \tag{2}\]  
where \(W_{i}\) is the resultant velocity at the \(i\)th control point and \(c_{i}\) is the chord of the \(i\)th blade element. To take into account the three-dimensional rotational effect, the 2D airfoil data is modified by the Du-Selig stall-delay model [20].
## 3 Methods
### Feature Extraction
#### 3.2.2 Heart Rate Variability (HRV))  
Heart rate variability (HRV) signifies the physiological variations in the intervals between successive heartbeats and can be discerned from electrocardiogram (ECG) data. It embodies the ability of the cardiovascular system to adapt to an array of stimuli, both within and outside the body. The connection between HRV and the autonomic nervous system has led to its recognition as a significant metric for evaluating emotional states.  
The autonomic nervous system consists of the sympathetic and parasympathetic nervous systems. The former triggers the body's \"fight-or-flight\" response during stress, while the latter modulates rest and digestion. Together, they maintain a delicate equilibrium, modulating cardiovascular functions, such as heart rate, to meet emotional and environmental demands.  
HRV analysis offers a window into this sympathetic-parasympathetic nexus, yielding vital clues about a person's emotional condition. In Figure 3, we illustrate the HRV patterns corresponding to five distinct emotional experiences, demonstrating the potential of HRV as a tool for emotional assessment.  
Figure 2: ECG graph samples showing distinct patterns corresponding to the five defined emotional states: excitement, happiness, anxiety, calmness, and sadness.
## 4 Experimental Results
### Security Analysis
#### 4.5.1 Resisting Information Leakage Attacks
This is because the binary codes are randomly assigned by \(RNG\) with different random seeds for the same user, which leads to no correlation between multiple ADs. Therefore, it is practically impossible to retrieve biometric data and bio-keys when PV and AD are compromised.
## 5 Hybrid Localization Algorithms
### Centralized Localization Algorithms  
In this section, two centralized localization schemes are researched: 1) 3D multi-power area localization scheme (3D-MALS) and 2) Silent Localization Using Magnetometers (SLUM).
###### Abstract  
Phosphogypsum leachate significantly accelerates carbonate rock dissolution in karst regions. The dissolution mechanism of phosphogypsum leachate associated with carbonate rock interaction and the corresponding numerical simulation need further study. In this study, 3D digital core imaging was used to scan undisturbed carbonate rock specimens from phosphogypsum landfill sites, and corresponding 3D structural models were constructed. We carried out indoor dissolution experiments in which we used Scanning Electron Microscopy as well as Energy Dispersive Spectrometer to observe changes in the surface micromorphology and elemental content of the rock specimens under different dissolution conditions. A reactive numerical model was developed based on the 3D structural model obtained from 3D digital core imaging, and numerical simulation studies were conducted. The dissolution reaction between phosphogypsum leachate and carbonate rocks exhibited an initial rapid phase followed by gradual stabilization. The pH of the leachate showed an exponential negative correlation with the dissolution amount per unit area of the rock specimens, while a power-law negative correlation was observed between pH and chemical dissolution rates. The numerical model effectively reproduced the reactant concentration states observed in experiments, confirming its capability to simulate reaction processes within rock specimens. Simulation results demonstrated that preferential flow through fracture channels led to higher reactant concentrations near fractures due to incomplete reactions, whereas lower concentrations occurred in sub-fracture regions. As the fracture aperture increased, the concentration disparity between these regions became more pronounced, with higher concentration of reactants at the outlet.  
core-scale; 3D rough fracture; 3D digital core imaging; acidic wastewater; experimental and modeling study +
Footnote †: journal: Applied Sciences