esa-sceva/satcom-chunk-collection huggingface dataset:
# Complex-Order Models: A System Identification Point of View
## 4 A Use Case in System Identification
To this aim, it employs various information on current system state (engine speed, air pressure in the intake manifold, common-rail pressure, etc.). On this basis, the unit determines the timing of injectors and the command to the valve. As previously mentioned, the objective in this complex process is to achieve an accurate regulation of the gas pressure in the common rail. If one considers the operation of several electro-mechanical elements or the dynamics of most physical processes occurring in the CNG injection system, then constitutive differential equations of integer order can be derived. However, the resulting integer-order models are not able to fit experimental data and satisfy the control performance and robustness indexes well--as can be easily understood by recalling the famous \"Procrustes' bed\" example [45]. This fact can be attributed to the complexity of time and spatial dynamics that are not easily and simply described by ordinary and partial differential equations of integer order. Namely, the literature proved that many physical systems show behaviors that are modeled by non-integer-order--also misnamed as \"fractional-order\"--differential equations or transfer functions, in case of input-output relations [46]. In the case of the CNG injection system, it is difficult to etablish a priori that the selected class of models will be appropriate to capture the underlying process dynamics; however, such models can be compared with a more general model--namely, the model with aperiodic CO-RV elements, which is introduced to overcome fitting problems given by both integer- and non-integer-order models. In general, the model structure is not known in advance and the available data are such that some frequency-domain methods [47; 48] cannot be applied. However, the selection of the most suitable model structure is based on the frequency response characteristics provided by an ARX model, which is identified by the classical least squares method. In the considered problem, injection basically depends on the common-rail pressure regulation around reference values established by the electronic control unit (ECU), which are determined by the operating conditions (speed, power request, etc.). Namely, the opening time intervals of the injectors are precisely adjusted by the ECU and do not represent a hard control problem. Therefore, the model should be identified to describe, predict, and control the common-rail pressure dynamics. Such pressure is affected by  
Figure 5: Representation of the gas-injection system. the inflow from the main chamber and the control chamber and by the outflow from the injectors, which is obviously strictly related to the timing of the injectors, taken as a disturbance input. Then, the command to the solenoid valve is selected as the model input, and the common-rail pressure is selected as the output.
# Astronomical Investigation to Verify the Calendar Theory of the Nasca Lines
## 4 Results  
Based on the literature, it could be proven that the observation of the movement of the celestial bodies, especially the Sun, was of great importance for the pre-Columbian cultures. Numerous structures, and also geoglyphs, were aligned with the Sun. [PERSON] suspected that the course of the Sun also played a special role for the Nascas. She assumed that the Nasca shamans used the geoglyphs to determine the annual calendar of agricultural and ceremonial activities, for example, to predict the times for sowing and harvesting. She also suspected that the figures at the pampa represent the stellar constellations of the Nasca culture.  
During her more than 40 years of research, [PERSON] found numerous lines, surfaces and figures with an orientation towards the Sun, several stars and the Moon. The examination of the geoglyphs found by [PERSON] with an astronomical orientation towards the Sun and prominent stars during the Nasca period has been verified within this project.  
In order to prove the calendar theory of [PERSON], however, a statistically reliable examination of all geoglyphs is necessary. Therefore, in a first step, all lines with a width of up to 50 cm and of the type \"straight line\" were examined with regard to their alignment with the Sun and prominent, very bright stars.  
First of all, it was found that of these 2308 lines, only 569 point in the direction of any sunrise or sunset and of these, only 99 lines have a correlation with solstices, equinoxes or zenith passages. This corresponds to around 4% of all lines of the type \"straight line\". If one assumes that not only the solstices and equinoxes were of interest to the Nasca people, but also important seasonal events such as the beginning of the rainy season in the Andes, then other Sun positions could have been of interest too. Therefore, more precise agricultural knowledge must be included in the investigations.  
Even with the stars, the result is not very satisfactory. Thus, over the entire period of the Nasca culture, there are always hits, i.e., lines that point to the selected very bright stars, but there is no accumulation in a certain period. It is also interesting that Sirius, the brightest star at the firmament, has the fewest hits. Hence, the number of hits does not allow any conclusions whether the hits are actually astronomically relevant lines or whether they are purely random.
## 3 Experimental Setup
### Pre- and Post-Processing and Data Augmentation  
The size of each raw ultrasound image was 2574 \(\times\) 640 pixels and was resized to 256 \(\times\) 64 pixels through image pre-processing, maintaining the aspect ratio of the original image. The resized ultrasound images were randomly flipped and rotated for data augmentation. The objective of the experiment was to develop a segmentation architecture and to benchmark its performance against the original U-Net, Attention U-Net, and MultiResUNet. This requires no specific pre-processing except that the input images were resized to fit into the GPU memory, and the pixel values were divided by 255 to bring them into the [0, 1] range. During post-processing, the image was resized back to the original size of the raw images to ensure that the image size did not impact the ultrasound curve angle (UCA) calculation for scoliosis.
# Optimized Architecture for Efficient OFDMA Network Design
## 3 Analytical Model for OFDMA Networks
### Model Assumptions  
The analytical model is based on a set of assumptions regarding the system, channel, and traffic.
## 4 Results and Discussion
### Nanofluid Characterization  
The presence of dispersant in NFs plays a crucial role not only in terms of influencing their stability, but also their thermophysical properties. Moreover, two-component theoretical models to predict the physical and transport properties of NFs do not take into account the contribution of the dispersant [36]. Thus, the thermal conductivity (\(k_{NF}\)), dynamic viscosity (\(\mu_{NF}\)), density (\(\rho_{NF}\)), and specific heat capacity (\(C_{pNF}\)) of the prepared TiO\({}_{2}\)-W NFs were determined experimentally. The convective heat transfer coefficient in NFs depends on these thermophysical properties [37].
# Outdoor Node Localization Using Random Neural Networks for Large-Scale Urban IoT LoRa Networks +
## 3 Related Work
In addition, RNN accurately predicted unseen patterns not included in the training data when compared with the conventional ANN performance [43]. RNN outperformed ANN during run-time though at the expense of a greater training time [44]; the authors also reported that RNN had a stronger generalization capacity for the training phase uncovered patterns. Furthermore, a performance analysis of different models of the proposed RNN-based localization system was evaluated in our previous published work [45]. Nevertheless, RNN application is still under investigation and yet to be fully applied in developing and evaluating end device localization systems in general, specifically using LoRaWAN in a large, dense urban environment.
# A Poisson Process-Based Random Access Channel for 5G and Beyond Networks +
## 2 Related Research Works
[20] enhanced the RACH procedure by obtaining the approximate characterization of UEs' interference in a wireless system. Their derived analytical expression of success probability helps to consider the channel collision and the preamble transmission. The authors further extend their proposed RACH success probability analysis for multiple time slots by modeling the queue evolution. In Reference [21], the authors address excessive congestion and channel collision in the RACH due to massive users' access. They propose a dynamic adjustment of the backoff parameters based on the number of contending devices. The vibrant use of backoff parameters in a RACH scheme achieves the enhanced channel access success probability for statics access and random access with a slight increase in the access delay. Another work in Reference [22] proposes a Timing Advance-based Preamble Resource Expansion (TAPRE) scheme for RACH procedure, which adjusts time slot for preamble transmission to reduce the collision probability effectively. The authors achieved this with a Resource Allocation Wait (RAW) protocol, which efficiently reduces RA failures. However, these works considered enhancing the existing uniform distribution-based RACH mechanism.
# Resistance of Concretes to External Chlorides in the Presence and Absence of Sulfphates: A Review
## 3 Resistance of Concrete to External Chloride in the Presence of Sulphate
### Effect of Exposure Conditions  
A number of previous studies showed that exposure conditions have significant effects on the deteriorations caused by chloride and sulphate attacks, whether in combination or in isolation. Most studies concluded that cyclic wetting and drying conditions are more devastating than permanent submersion due to the build-up of salts during drying stages [22; 134; 152; 153]. These exposure conditions are well-noted and classified accordingly in the European Specification for concrete EN 206 [25]. However, inconsistencies in compositions of the combined chloride-sulphate solutions, as highlighted in Table 5, make comparisons across different findings difficult. Future studies may consider how this may be resolved.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**20 °C**} & \multicolumn{3}{c}{**20 °C**} & \multicolumn{3}{c}{**38 °C**} \\  & & Ogirigbo [76] \& **Ukpata [15]** & & **[PERSON] \& [PERSON] [16]** & **[PERSON] [76] \& **[PERSON] [15]** \\ \cline{3-8}
**Curing Duration (Days)** & & \multicolumn{3}{c}{**D\({}_{\text{s}}\) (m\({}^{2}\)/S)**} & \multicolumn{3}{c}{**D\({}_{\text{s}}\) (m\({}^{2}\)/S)**} & \multicolumn{3}{c}{**D\({}_{\text{s}}\) (m\({}^{2}\)/S)**} \\ \cline{3-8}
**Binder/Temperature** & \multicolumn{1}{c}{**Pure CI**} & **Combined** & **Pure CI** & **Combined** & **Binder/Temperature** & **Pure CI** & **Combined** \\ \cline{3-8}  & & (\(\times\)10\({}^{-12}\)) & (\(\times\)10\({}^{-12}\)) & (\(\times\)10\({}^{-12}\)) & (\(\times\)10\({}^{-12}\)) & & (\(\times\)10\({}^{-12}\)) & (\(\times\)10\({}^{-12}\)) \\ \hline
7 & C1-20 °C & 51.50 & 1.40 & - & - & C1-38 °C & 44.10 & 2.03 \\
7 & 30S1-20 °C & 5.41 & 0.76 & - & - & 30S1-38 °C & 3.56 & 0.67 \\
28 & C1-20 °C & 17.50 & 1.43 & 5.27 & 3.72 & C1-38 °C & 7.92 & 2.01 \\
28 & 30S1-20 °C & 3.87 & 0.64 & 2.94 & 2.55 & 30S1-38 °C & 2.47 & 0.94 \\ \hline \hline \end{tabular} Note: C1-20 °C = CEM 142.5R samples cured at 20 °C; 30S1-20 °C = samples with 30% GGS in CEM I cured at 20 °C, etc.  
\end{table}
Table 4: Comparisons between chloride diffusion in mortars exposed by submersion to pure chloride and combined chloride–sulphate solutions from different authors [15; 16; 76].
## 2 Definitions  
This paper introduces two specific concepts:  
1. Artificial patch: this consists of aggregating all the peripheral areas that characterize artificial areas to allow the continuous generation of consistent data on \"artificialized\" areas. It consists of applying successive dilation/erosion operations characterized by a continuity distance to the artificial areas. The artificialized patch concept is an innovative extension of the urban patch concept. The principle is similar but our definition of the artificial patch differs from that of the urban patch in its components and in the continuity distance used: * We defined three main categories of constituent objects: (i) housing areas; (ii) commercial and business areas; and (iii) facilities and infrastructure (including quarries and landfills). * We applied a continuity distance of 100 m, which is the best compromise in peri-urban and rural areas. This distance was defined after trials revealed overestimation of the artificial area when the standard continuity distance of 200 m was used to calculate urban patches, and underestimation when a distance of less than 100 m was used
2. Artificial sprawl: this concept describes the irreversible land conversion by artificialized areas. It is calculated by diachronic analysis of artificial patches.
## 3 Resource Scheduling and Collision Resolution in Sidelink Mode 4
### Sensing  
The resource scheduling in C-V2X is done over a two-dimensional space, where the two axes are time and frequency (Figure 1). The wireless resource grid is divided into subchannels in frequency and subframes in time. In the frequency axis, the granularity of resource allocation is a subchannel. Each block in the grid (e.g., small colored boxes in the figure) is called the single-subframe resource, and it is composed of multiple resource blocks (RBs). Since there is no central coordinator for the resource scheduling in SL Mode 4, each UE monitors the resource usage by other UEs before selecting the resource for its BSM transmission. This is called _sensing_. The resource that has been used (or is predicted to be used) by other UEs are marked busy and not selected for transmission to prevent the message collision.  
In the sensing window, 1000 subframes (1 s) in the immediate past are monitored. For pedestrian devices, _partial sensing_ is allowed for battery saving. Whether a given resource is being used is determined based on the RSSI threshold called the sidelink RSSI (S-RSSI) threshold, above which a single-frame resource is considered busy. The standard does not specify the value of this threshold, but the 3 GPP working documents usually compute this threshold by adding -107 dBm/RB in the subchannel [37]. Based on the sensing result, the next selection step determines which single-subframe resource it should exclude from the selection window as unusable. Essentially, the resources that have  
Figure 1: Reselection in SPS; \(p\) is the resource keeping probability.  
been used by other UEs in the sensing window enable us to determine if a resource in the selection window will likely be available.
# Active Control Loop of the BOROWIEC SLR Space Debris Tracking System
## 2 Satellite Laser Ranging Process
### Laser Beam Propagation
#### 2.3.1 Beam Divergence
Such a divergence value guarantees a high energy density, which is necessary to acquire a detected photon event from an uncooperative object. However, such a divergence value combined with the ephemeris uncertainty described in Section 2.2 may lead to acquisition difficulties. The relatively small cross-section of the laser beam on the orbit in the form of the spot size and an ephemeris with high uncertainty may prevent effective spot measurement of the object.
## 1 Introduction
### Qualification to Mass Production  
The main difference between processes during the development stage and regular qualified production is the number of corresponding tests that are required. The first parts should be tested extensively for correct grain size in order to achieve the desired part life, then tested for cracks and other unwanted deviations with use of chemical penetrants, and finally verified with blue light scans to assess whether every small portion of the surface is within the desired tolerance.  
Non-destructive tests are not enough at the prototyping stage. During the next step, the part needs to be cut into slices to check wall thickness and deviations. The number of checked sections and pairs of points is high and cannot be reduced without lowering the overall standards. The overall cost of tools and corresponding fixtures is incredibly high but it can be adjusted using vendor guarantees before mass manufacturing starts.  
After the process has been approved, qualified, and verified for repeatability, simpler (relying on simple math and statistics) methods to check the produced vanes can be employed.
## 2 Study Area, Data and Methods  
### Study Area  
The NYRD is composed of the northern Anhui and Jiangsu provinces and Shanghai, ranging between 114\({}^{\circ}\) and 122\({}^{\circ}\)E and 29\({}^{\circ}\) and 36\({}^{\circ}\)N (Figure 1). The NYRD covers an area of 176,960 km\({}^{2}\), consisting of 73% cropland, 16% grassland, 5% built-up land, 4% water bodies, and 2% forest (Figure 1). Three EC flux sites were representative of typical rice-wheat-rotation cropland landscapes found in this cropland (Figure 1, inset map) [24; 25]. The soil pH value (H\({}_{2}\)O), soil organic carbon and soil total nitrogen in topsoil (0-0.3 cm) for our study area mainly ranged between 5.5 and 7.2, 1.2, 0.1 and 0.15%, respectively, according to the results of [PERSON] et al. [28]. Here, the winter wheat grows from November to late May. At the beginning of June, the rice paddies are flooded, plowed and narrowed to incorporate the wheat straw residue from the last wheat growing season [29]. Then, one-month-oldrice seedlings are transplanted to the leveled field in mid-June and harvested in early November (Figure 2a), which can be indicated by the seasonal dynamics of the 8-day leaf area index (LAI) averaged from 23 weather stations and 3 EC stations during the period of 2014-2018 (Figure 2b). The rice/wheat canopy height can reach about 1-1.2 m at the peak LAI growing seasons. The local climate is sub-tropical monsoon-type, with a mean annual (2014-2018, calculated from the 23 surface meteorological stations in Figure 1) air temperature of 16 \({}^{\circ}\)C and rainfall of 1100 mm.  
Figure 1: MODIS landcover maps (resolution: 500 m) in 2016 and the meteorological stations in the North Yangtze River Delta region. The inset map indicates the distribution of rice–wheat-rotation cropland areas in China.  
Figure 2: (**a**) Crop calendars for the rice and wheat in the North Yangtze River Delta region. (**b**) Time series of the 8-day leaf area index (LAI) for the rice–wheat-rotation croplands averaged from 23 weather stations and 3 EC stations during the period of 2014–2018 of the North Yangtze River Delta.
## 3 The Critical Importance of Product Identity in Agricultural Supply Chains
### Industry Implementations in Agricultural Supply Chains
In China, after several high-profile food safety scandals, major e-commerce players such as JD.com and Alibaba partnered with producers to implement blockchain tracking for products like beef, milk powder, and cooking oil as part of broader government-endorsed food traceability programmes. For instance, JD.com worked with an Australian beef supplier to record every step of beef production on a blockchain, so Chinese consumers buying the meat could trace its farm of origin, slaughter, and shipping details via an app [56]. This was aimed at restoring trust in imported meats. In another example, the European Union has been exploring blockchain through its European Blockchain Services Infrastructure (EBSI) initiative. While EBSI covers many use cases (from digital credentials to customs), one focus area is supply chain traceability for agricultural goods to enhance cross-border transparency and compliance. Some governments are also leveraging blockchain for specific agricultural supply chains, e.g., tea producers in Malawi have piloted blockchain to track tea from estates to auctions to buyers, improving fair-trade claims verification; the Indian state of Andhra Pradesh tested blockchain for monitoring crop supply and connecting farmers with markets as a means to prevent price manipulation by intermediaries. Success factors and lessons: Across these implementations, a few success factors stand out. Stakeholder collaboration is crucial--the entire chain (farmers, processors, distributors, retailers) needs to participate and input data for the blockchain to provide end-to-end visibility. Many successful projects started with a consortium or a dominant buyer driving adoption (like Walmart enforcing supplier participation or a government creating incentives). Another factor is user-friendly integration, that is, solutions that succeeded tended to integrate with existing workflows (e.g., mobile apps for farmers or IoT sensors auto-uploading data) so that using the blockchain does not become a burden. The Carrefour case also highlighted the importance of consumer engagement: informing customers about the ability to scan products and see provenance helped translate transparency into brand loyalty and sales [4]. On the other hand, barriers such as limited connectivity in rural areas or reluctance to share data have stalled some pilots. Nonetheless, the growing list of real-world applications suggests that blockchain is gaining traction in agri-food supply chains, transforming how product identity and traceability are managed in practice.
## 1 Introduction
RoEO is used in traditional medicine to enhance physical and mental states and to treat headaches, stomach pain, rheumatic pain, epilepsy, dysmenorrhea, spasms, depression, hysteria, and nervous agitation. It is also utilized to improve memory capacity [8,10,13,17,18,19]. Numerous studies have investigated the pharmacological actionsof RoEO and extracts obtained from rosemy leaves, reporting various properties, including antioxidant [6; 9; 12; 20; 21; 22], anti-inflammatory [8; 23], antihypertensive (rosmarinic acid) [13; 24] or antihypotensive (RoEO) [25; 26], antihypercholesterolemic [13; 27], antihypoglycemic [13; 28; 29], antiglycative (mitigation of age-related pathology effects) [30; 31], antibacterial [10; 12; 32; 33], antifungal [12; 33; 34], antiviral [13; 35], neuroprotective [13; 17; 22], antidepressant [36; 37], hepatoprotective [38; 27], nephoprotective [39; 40], antitumor, antiproliferative [9; 13; 20; 21], antiangiogenic [41], antiallergic (in cutaneous allergies) [42; 43], cutaneous texture restoration [6; 44; 45], radioprotective-antimutagenic [13; 46; 47] effects. In recent years, antibiotic resistance has become a major concern worldwide. Therefore, EOs could be a natural alternative to reference antibiotics and a promising therapeutic strategy against antibiotic-resistant bacterial strains responsible for nosocomial infections [48]. Moreover, due to their bioactive compounds, EOs are used as natural antioxidants mainly in the food industry, medicine, pharmaceutical technology, and cosmetics dermatology (e.g., replacing the synthetic additives with negative influence on human health) [49]. The paper is structured considering RoEO characterization, starting from the plant material, EO extraction, then seasonal variations in the chemical profile and antibacterial and antioxidant activities, comparing them to the most relevant specialized works. The aim of this study is to report for the first time, over a 12-month period, the seasonal variations in chemical composition and antibacterial and antioxidant activities of _R. officinalis_ EO from Southwestern Romania (Oltenia region). Using a comprehensive GC/MS method, the constituents of RoEO were identified and quantified by comparing their mass spectra with reference spectra from the National Institute of Standards and Technology (NIST) Library 2020. The microdilution method (96-well plates) was applied for the determination of _Staphylococcus aureus_ minimum inhibitory concentration (MIC) values. Moreover, 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2\({}^{\prime}\)-azino-_bis_(3-ethylbenzothazoline-6-sulfonic acid) (ABTS), and hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)) radical scavenging assays were employed for the analysis of the antioxidant activity.