esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Theory of TDLAS  
TDLAS is a technique that measures the absorption spectra of the selected gas using fast response continuous lasers. The principle of TDLAS is based on Lambert Beer's law. The main part of the TDLAS system is the diode laser of which, working wavelengths are adjusted to the range of absorptive wavelengths of the target gas. When the incident laser beam passes through the target gas, the spectra of the transmitted laser beam at the opposite side have absorptive spectra at certain wavelengths that are an optically inherent characteristic of the gas. Accordingly, the number density (\(n\)) of the measured gas species is related to the absorbance of light, as in the following Equation (1):  
\[\frac{I_{t}(\lambda)}{I_{0}(\lambda)}=exp\{A_{\lambda}\}=exp\{-\sum_{i}\limits {(P\cdot n_{i}\cdot L\sum_{j}S_{i,j}(T)G_{\pi i,j})}\} \tag{1}\]  
Here, \(I_{0}\) is the incident light intensity, \(I_{t}\) the transmitted light intensity, \(A_{\lambda}\) the absorbance, \(n_{i}\) the number density of species \(i\), \(L\) the path length, \(S_{i,j}\) the temperature-dependent absorption line strength of the absorption line \(j\), \(P\) is the pressure and \(G_{\pi i,j}\) the line broadening function. Broadening function \(G_{\pi i,j}\) has been approximated by the general Voigt profile represented [20].  
The intrinsic absorption wavelengths of H\({}_{2}\)O, near 1388 nm, were used for temperature sensitivity measurements of the combustion environments. Figure 1 shows the absorption spectrum of H\({}_{2}\)O in the near-infrared region (1388 nm), which has been calculated by the HITRAN database [21]. Three absorption lines located at 1388.139 nm (#1), 1388.328 nm (#2), and 1388.454 nm (#3) have remarkable temperature dependence at three different temperatures (300 K, 700 K, 1500 K), and they were utilized for temperature measurements.  
Figure 1: Relative intensity of theoretical H\({}_{2}\)O absorption spectra (1388 nm–1388.5 nm).  
Figure 2a shows the theoretical absorption intensity variations of three dominant wavelengths (#1, #2, #3) for temperature variations of H\({}_{2}\)O. Figure 2b represents the temperature dependency of the ratios of the three dominant wavelengths. It can be said that the ratio of #1/#2 has a strong linearity for temperature increments. In the CT process, this linearity is utilized for temperature calculations, in which the calculation errors between the temperature obtained from the theoretical absorption spectra and the temperature obtained from the experimental absorption spectra.
## 2 Materials and Methods
### Data Collection  
UAV imagery was obtained using a DJI Phantom 4, which is equipped with a built-in GNSS system and a CMOS camera (12.4 MP) with 4000 \(\times\) 3000 resolution. Each case study consisted of three different flight grids (nadir, oblique, and nadir and oblique). During these distinct campaigns, flight characteristics were kept the same (Table 2). Specifically, flights were executed with a 90% along-track overlap and a 75% cross-track overlap. However, the flight acquisition altitude was adapted to the topography of each study area, with the aim of extracting photogrammetric products with spatial resolution between 2.3 and 3.5 cm (Table 2). The collected UAV imagery of each area was classified into three groups of data. The first group included nadir-only images with a 90-degree gimbal pitch angle; the second group consisted of oblique-only images with a 65-degree gimbal pitch angle; and a synergistic use of nadir and oblique imagery was selected for the third group.  
In addition, GCPs were distributed throughout the survey areas in order to orient and match the aerial imagery to data measured terrestrially. GCPs were collected using a Leica GS08 GNSS receiver. Coded targets were created according to the general recommendations of Agisoft Metashape software [35], and were printed on matte finish plastic boards. These targets were used as GCPs (Figure 2). Furthermore, large rectangular aluminum targets were placed in the survey areas for comparison and validation of the photogrammetric outputs (Figure 3). These aluminum targets had specific dimensions and a hole in each corner, in order to be accurately measured with a GNSS sensor.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Case Study ID** & **Acquisition Geometry** & **Number of Photos** & **Average Flight Altitude (m)** & **Average GSD (cm)** & **Along the Track Overlap \%** & **Along the Track Overlap \%** \\ \hline \multirow{3}{*}{Moira} & Nadir & 189 & & & & \\  & Oblique & 174 & 110 & 3.5 & 90 & 75 \\  & Synergistic use & 363 & & & & \\ \hline \multirow{3}{*}{Egremmi} & Nadir & 97 & & & & \\  & Oblique & 84 & 60 & 2.3 & 90 & 75 \\  & Synergistic use & 181 & & & & \\ \hline \multirow{3}{*}{Zachlorou} & Nadir & 60 & & & & \\  & Oblique & 210 & 70 & 2.5 & 90 & 75 \\  & Synergistic use & 286 & & & & \\ \hline \multirow{3}{*}{Massarista} & Nadir & 65 & & & & \\  & Oblique & 70 & 110 & 3.5 & 90 & 75 \\  & Synergistic use & 135 & & & & \\ \hline \multirow{3}{*}{Patras Port} & Nadir & 96 & & & & \\  & Oblique & 85 & 60 & 2.3 & 90 & 75 \\ \cline{1-1}  & Synergistic use & 181 & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Characteristics and parameters of UAV campaigns.  
Figure 2: Printed GCP pattern, distributed throughout the survey area during UAV campaigns.
# Challenges Associated with Implementing 5G in Manufacturing
## 4 Infrastructure Requirements for 5G
### 5G in a Heterogeneous Network Infrastructure  
Future 5G networks will have to provide a significantly higher system capacity than today and solve the anticipated spectrum crunch. Communications regulators globally are managing the allocation of spectrum for 5G usage; typically, the spectrum is being auctioned to telephone companies (Telcos) who are then offering a range of solutions to industry. In Europe, three major frequency bands have been made available for 5G use. These three bands are 700 MHz, 3.6 GHz and 26 GHz. It should be noted that spectrum regulators in some countries have started the process of opening up shared spectrum for local use in specific bands, which will enable the deployment of private 5G networks and enable easier research and development deployments. For example, the regulator in the USA opened up the 3.5 GHz band as of January 2020 for commercial use known as the CBRS (Citizens Broadband Radio Service) band.  
In addition to cellular advances, Wi-Fi networking is also getting significant upgrades and this supplementing technology will add to the 5G ecosystem. Each technology offers individual improvements; they will also work in tandem to fill in gaps in environments where other technologies may not be ideal. The Wi-Fi Alliance is referring to the IEEE 802.11 ax specification as Wi-Fi 6 because it's the sixth generation of Wi-Fi.  
Harnessing 5G's capabilities in terms of security, synchronizing and network slicing times between devices will be a challenge for industry. These challenges are expected to take some time to be solved. Therefore, while 5G should be seen as the solution going forward, the timeline to address those issues should make companies plan a transition approach to adopting 5G, and utilising 4G LTE is a viable solution as a transition to 5G allowing the easier and potentially more affordable adoption of 5G when it is more mainstream.
Each converter stage has its own controller and filter circuit. The PI controller is implemented in this design due to its simplicity, robustness, and excellent control action. The transfer function model of each converter is derived from the state-space model. By using the transfer function equation, the stability of the proposed design is tested in terms of frequency response, time response, controllability, and observability. Furthermore, the Simulink design of the proposed system is established in MATLAB, and the controller is designed through MATLAB SISOTOOL. The state-space model is designed for the stability study with and without a controller. In the proposed methodology, the user can simply design the controller part from the unstable model through MATLAB SISOTOOL, thereby making the system robust and stable. Thus, researchers can easily measure the system's stability, sensitivity, controllability, and observability. This article is organized as follows. Section 1 provides an introduction to SST and a literature review. Section 2 outlines the fundamentals and different types of SST topology. In Section 3, the continuous-time average state-space model and its transfer function model are formulated. This section categorizes the converter stage into the input, isolation, and output stages with the state-space model. Finally, the result and discussion parts of the proposed model are provided in Section 4, followed by the conclusions in Section 5. The main contribution of the paper is summarized as follows:  
* The state-space model of each converter is derived. * The stability of converters has been analyzed by integrating it with additional control methods. * Time-domain and frequency-domain performance have been shown to measure the system's stability. * The proposed model has been simulated and validated using an OPAL-RT real-time digital simulator.
# Novel Fault Injection Attack without Artificial Trigger
## 1 Introduction
### Related Works  
Recently, theoretical DFA methods on various cryptographic algorithms have been studied. In 2012, [PERSON] et al. proposed a DFA method on the HIGHT block cipher [8], which assumes that it is possible for an attacker to inject a random byte fault in the input of the 28 th round [9]. A DFA method on ARIA block cipher [10] was suggested by [PERSON] et al. in 2013 [11]. An attacker who uses this method to reveal the master key needs to inject some faults in the input of the last round of encryption and decryption. [PERSON] et al. proposed a DFA method on LEA block cipher [12], which uses a single-bit fault model [13]. DFA methods on SIMON and SPECK block cipher [14] were suggested by [PERSON] et al. [15]. A DFA method proposed by [PERSON] et al. on CHAM-128/128 cipher [16] can extract the master key using about 24 correct-faulty ciphertext pairs as a simulation result [17]. Only studies such as the above DFA papers have simulational experiment results. This means these DFA methods use the assumption that a trigger is set up to inject faults at the desired operations. Moreover, it does not guarantee that these can be applied to actual devices.
## 1 Introduction  
The condition of roads is easily one of the more important signs of economic standards and general well-being in a given country or region. Early detection and repair of pavement defects avoid further degradation and bring down the overall road maintenance cost. Efficient and timely road inspection is therefore one of the key elements of a successful pavement management system. Yet, periodical road surveys tend to be rather costly and time consuming if carried out in the traditional way, i.e., by human visual inspection of the road surface.  
In recent years, automatic image based road distress evaluation has become an option [1]. Although it is still an open research problem and subject to environmental conditions such as illumination level, shadows cast by nearby objects, etc., great progress has been made in this area, and various methods ranging from filtering and thresholding to artificial neural networks have been employed to carry out the task.  
Public infrastructure undergoes aging, as well as degradation due to weather conditions. The present research is motivated by the fact that in Estonia, the daily temperature can fluctuate around 0 \({}^{\circ}\)C for more than five months a year. Therefore, ice and snow melt during the day and freeze again at night. This leads to accelerated expansion of cracks and other defects, thus requiring frequent road inspections.
# Bearing Fault Diagnosis Based on Improved Convolutional Deep Belief Network
## 1 Introduction
Based on the standard CDBN model, this study introduces [PERSON]'s optimization algorithm and optimizes the structure of the CDBN. An improved CDBN model is proposed to enhance diagnosis accuracy. Unlike image processing, in the case of fault diagnosis, the raw data will probably be noisy. The feature extraction capability of a standard CDBN is insufficient, which is the reason of conducting band-pass filter to pre-process the data. The main constructions of the proposed method are listed as follows:  
1. A band pass filter has been introduced to the preprocessing step to filter out noise;
2. Qualitative and quantitative diagnoses of bearing faults can be effectively implemented;
3. Both single fault and compound faults can be effectively identified;
4. A comparative experiment under different operation loads further confirmed the reliability of the model. The rest of the paper is organized as follows. Section 2 contains an introduction of the theoretical background of a CDBN and the structure of the proposed method. The experimental results are discussed in Section 3. Finally, in Section 4, conclusions are summarized.
# Electrospinning of Chitosan for Antibacterial Applications--Current Trends
## 5 Electrospinning of Chitosan
### Auxiliary Solvents and Composites
As for the solution concentration, it was found to simultaneously increase with the average diameter of the fibers with a minimal and maximal limit. Below 3 wt% of CS/PVA solution, it was impossible to obtain bead-free continuous nanofibers, while above 10 wt%, the solution became too viscous and the electrospinning process proved difficult to maintain. As a result, the electrospinning blend's optimal concentration should be between 7 and 9 weight percent [127]. The combination of PVA and CS composite materials leads to increased toughness, controlled biodegradability, and chemical functionality. As CS may interact with AgNO\({}_{3}\) and decrease the repulsive force between ionic groups inside the polymer backbones, adding a small quantity of AgNO\({}_{3}\) to a PLA/CS blend solution could optimize its electrospinning ability, resulting in a shift from a bead-on-fiber structure to uniform fibers [128]. In addition, the combination of CS with Ag nanoparticles sustained antibacterial activity and was greater than that of the individual components [129]. Derivatives of chitosan, such as quaternary ammonium salts, are anticipated to improve chitosan's water solubility and antibacterial activity. The newly synthesized polymer N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan chloride (HTCC) became water-soluble and electrospinning when polyvinyl alcohol (PVA) was added. It was discovered that increasing HTCC concentration in blends improves the electrospinning and decreases the fiber diameter. Nanofibrous PVA-HTCC mats showed good antibacterial activity against _E. coli_ and _S. aureus_[130].
# Standalone GPS L1 C/A Receiver for Lunar Missions
## 2 The _WeakHEO_ Receiver Architecture  
The architecture of the _WeakHEO_ receiver is shown in Figure 1. The system comprises of three main elements as follows.  
* **A tri-band (L1, L2, L5) RF front end**, which amplifies, filters and down converts the GNSS signals to an intermediate frequency (IF) where they are sampled. The reported initial implementation is focused on processing and utilisation of the GPS L1 C/A code signal. However, a triple frequency L1, L2, L5 front end (an early version of the front end in [18]) was selected to allow future expansion to these frequencies. A high sampling rate is used to enable the receiver to support precision tracking architectures and additional wider bandwidth signals in the future. A common IF frequency of 53.78 MHz is used for all three bands and signals are sampled at 40.96 MHz with 4-bit resolution. The RF front is driven by a stable, low-phase noise Oven Controlled Crystal Oscillator (OXCO).
* **A DE3 FPGA platform**. An FPGA platform was required to allow custom designs of the acquisition and tracking engines within the receiver. The _WeakHEO_ receiver uses the same development platform and builds on the FPGA-based architecture of the \"Signature\" receiver developed by ESPLAB in EPFL [19]. Its core component is a Stratix III FPGA (Field Programmable Gate Array) receiving the parallel sampled data from the RF front end. The FPGA contains a softcore NIOS II (32 bit RISC) processor and performs all the high sensitivity acquisition, tracking and navigational data decoding processes. Raw measurements (pseudoranges, pseudorange rates, signal parameters, time, _etc._) are passed to the PC through a UART interface at a rate of 0.1 Hz. Note that this rate has been chosen in order to allow the real-time processing of the navigation solution on the PC (currently programmed in Matlab). In the next version of the receiver, a faster update rate will be selected. An external memory (DDR2 SDRAM) connected to the FPGA is also used as buffer for the acquisition.
* **A PC**, The PC then performs the navigation solution in real time or can record and compute the orbital filter calculations offline.
# Application of Machine Learning in the Identification and Prediction of Maritime Accident Factors
## 2 Materials and Methods
### Database and Codification  
The information obtained from the CIAM [19] database shows the more relevant accidents and their classically identified variables commonly considered, such as wind force and the ship dimensions, among others. Despite this, there is a lack of mathematical studies of this complex process that relates objective and subjective parameters commonly associated with the human factor.  
The information was codified, as it is shown in (Tables A1-A8). This codification was employed to develop a quantitative, and not qualitative, analysis. What is more, several histograms let us understand if the information complied with normality and parametric statistical studies.  
Once the codification was accomplished, a detailed study was developed to identify the amount of data that can be employed for statistical studies. In this sense, it was considered if there was data enough for all the considered variables in each accident. As a result, 276 accidents were considered. It was true that, when the accident was between two ships, there was enough information about only one of them. Based on this information, the most common values and their maximum and minimum ranges were identified for these accidents.
## 3 Results and Analysis
### Quantitative Impact of Urbanization on Compound Floods
#### 3.2.3. Drainage System  
Low standards in drainage systems are a significant contributing factor to urban compound floods. During large-scale heavy rainfall, overloading and overflow may occur when the capacity of drainage pipelines is exceeded, leading to surface water flooding [16]. Urban drainage systems have been excessively affected by high-intensity storms [87; 88], and conventional systems are often unable to handle the increased inflow caused by climate change [89]. The Storm Water Management Model (SWMM) is the most widely used tool for simulating urban drainage systems, capable of modeling inflow and outflow for any type of catchment area and providing flood loss data at different nodes [65].  
For example, [PERSON] et al. (2023) [90] applied SWMM to assess the flood risk in Maputo, Mozambique, affected by climate change, and simulated the restoration and future design of existing drainage systems. [PERSON] et al. (2022) [65] simulated the response of the drainage system in Gurugram City, India to a 5-year return period design storm and demonstrated that climate change poses a more serious threat to drainage systems than urbanization. [PERSON] et al. (2019) [91] studied Hohhot, China and found that annual expected flood volume changes caused by urbanization ranged from 194% to 942%, surpassing the impact of climate change under the RCP 8.5 scenario (35-794%). They emphasized the critical role of robust drainage systems in adapting to evolving flood risks in the city.  
The quantitative analysis of climate change drivers and urbanization factors influencing compound flooding reveals that, globally, the risk posed by each factor varies based on differences in geographical location, climate conditions, and levels of urbanization. For example, Shanghai, situated in a low-lying area along China's southeastern coast, frequently experiences storm surges and extreme rainfall events. Additionally, excessive groundwater extraction has led to significant land subsidence, and a high proportion of impervious surfaces further exacerbates flooding. Consequently, under the impacts of climate change, Shanghai's compound flood risk is primarily driven by storm surges, extreme rainfall, land subsidence, and impervious surfaces. Identifying and layering the predominant flood risk factors according to the specific characteristics of coastal cities is crucial for advancing research on compound flooding.
# Luminescence Tuning of Fluorinated Bistolanes via Electronic or Aggregated-Structure Control
###### Abstract  
Organic luminescent materials have a wide range of practical applications, but the understanding of the relationship between molecular structure and luminescent behavior is lacking. Herein, we synthesized fluorinated bistolanes with an electron-donating alkoxy substituent at one terminal and an electron-withdrawing substituent at the other to realize systematic control of the electron-density distribution. Evaluation of the phase transition behavior revealed that most of the fluorinated bistolanes showed liquid-crystalline (LC) behavior, with the phase transition temperature depending on the terminal substituents. Additionally, the fluorinated luminophores displayed intense photoluminescence (PL) in solution and in their crystal phases. Remarkably, the PL color shifted dramatically depending on the dipole moment (\(\mu_{\parallel}\)) along the long molecular axis; thus, PL tuning can be achieved through electronic modulation by precise control of the \(\mu_{\parallel}\) of the luminophore. Interestingly, in the LC phases under thermal conditions, the maximum PL band shifted by 0.210 eV upon phase transition from the crystal to smectic A LC phases, indicating that PL tuning can also be achieved by controlling the aggregated structure. These results offer a new molecular design for easily tunable PL materials using the molecular properties or external stimuli for promising applications, including light-emitting displays and PL sensing materials.  
Keywords: fluorine; \(\pi\)-conjugated molecules; photoluminescence; liquid crystals; electron-density distribution +
Footnote †: journal: Applied Physics Letters