esa-sceva/satcom-chunk-collection huggingface dataset:
# Forward Computational Modeling of Respiratory Airflow
## 3 Image-Based Structural and Spatial Geometric Models  
Medical imaging has provided the opportunity to visualize and track lung pathologies and phenotypical changes over time, response to treatment protocols, and allow for better insight into the functional behavior of the lung [29; 30; 31; 32]. Three-dimensional anatomic models of the lungs can now be generated rapidly based on a single breath hold image [33]. Both X-Ray computed tomography (CT) and magnetic resonance imaging (MRI) have allowed for the creation of high-resolution, subject-specific 3D structural, spatial, and functional models of airflow in the lung. These subject-specific models are useful for visualizing and studying personalized changes in airflow pattern, ventilation, particle deposition, and lung tissue deformation [4; 29; 34; 35; 36]. Such models also have utility in precision medicine, for testing new hypotheses and guiding clinical management. Moreover, techniques that quantify regional changes at distinct locations can be used to assess associations with measures of global lung function, such as plethysmography or spirometry. CT and MRI allow for the coupling of both CFD and ventilation distribution [14], as well as the matching of perfusion and ventilation distributions [1; 37]. [PERSON] et al. compared functional simulations from a modified 3D Weibel model that included spatial branching, and an image-based model from a CT scan of a cadaver lung cast, both having four branching generations [38]. They also demonstrated that the velocity fields in the image-based model are more complicated (i.e., more heterogeneously distributed) than in the Weibel model for airway segments in the same generation. The results further showed significant differences in regions of particle deposition between the two models. Although both models showed particle deposition at airway bifurcations, the image-based model showed particle deposition on airway walls while the Weibel model showed little to no particle wall deposition. This was attributed to the absence of airway curvature and surface irregularities in the Weibel model, which makes it insufficient to predict particle deposition.  
Although CT imaging can yield high spatial and temporal image resolutions, high radiation doses are required to evaluate various structural pathologies of the lung, thus limiting the availability of images from which 3D subject-specific models can be generated [39]. While MRI has advantages over CT regarding radiation exposure, it traditionally has a limited ability to depict lung anatomical details. Hence, new methods to optimize CT imaging with reduced radiation exposure while simultaneously acquiring high-resolution imaging scans are necessary. Both CT and MRI can be used to incorporate structural and functional changes associated with lung disease and pathology.
# Title-to-Length Coupling Analysis of an Off-Axis Optical Bench Design for NGGM
## 4 Global TTL Coupling
### Cross Coupling between Local and Global TTL
#### 4.3.4 Misalignment of the Rooftop Mirrors  
For the off-axis optical bench design, the angle between the rooftop mirrors is proposed to be 135\({}^{\circ}\). However, an angular offset occurs due to the assembly error, resulting in an additional OPD variation. For the TMA employed in the GRACE Follow-on mission, the initial beam coalignment is required to be better than 10 \(\upmu\)rad [22]. The misalignment and non-orthogonality of the three mirrors in the TMA contribute to the anti-parallelism errors between the RX and the TX beams. For the rooftop mirrors, the assembly of the rooftop mirrors is easier and a higher accuracy of beam coalignment is expected to be achieved. To investigate the global TTL coupling due to the misalignment of M1 and M2, offsets of the rooftop mirrors, respectively of 2.5 \(\upmu\)rad and 5 \(\upmu\)rad, are considered in our simulation. The results are shown in Figure 19. It can be seen that an offset of 5 \(\upmu\)rad results in a TTL coupling variation of less than 2.5 \(\upmu\)m/rad in the yaw degree of freedom, and causes no significant change in the pitch degree of freedom.  
Figure 17: Global piston effect results. The additional offset between the pivot point and the reflection point of the FSM mirror is set to be 11.5 mm in the simulation.  
Figure 18: Results of the global variation due to misalignment of the critical components. Different offsets of the critical components along the three translation axes are chosen, and the positions of the components are shifted. The global TTL coupling variations due to the offsets are given.
## 2 Related Work  
### Neural Radiance Fields  
NeRF [7] effectively integrates image-based 3D reconstruction techniques with novel viewpoint synthesis tasks. Unlike explicit 3D representation methods such as point clouds [11], voxels [12], or meshes [13], NeRF employs an implicit representation method [14] that encodes the appearance characteristics of 3D scenes within the weights of a neural network. However, implicit 3D representations often lack interpretability and are less efficient for line-by-line renderings of high-resolution remote sensing images. Additionally, the methods used to capture remote sensing images significantly differ from those of standard close-range cameras, resulting in greater distances between the objects and the camera. Constructing a neural radiance field directly in this context can lead to considerable computational redundancy in light state calculations. To address this issue, DoNeRs [15] focuses on obtaining real depth information and prioritizing important samples around object surfaces. However, acquiring accurate depth information from remote sensing images remains a significant challenge. To overcome this, ImMPI [16] introduces an implicit 3D scene representation using multiplane images (MPIs), and it provides innovative view synthesis for remote sensing imagery. This work also presents a specialized dataset, LEVIR-NVS, which is designed for constructing neural radiance fields in remote sensing images and consists of multiscenario, multiview data captured by drones. Nevertheless, NeRF and its variants, which primarily rely on implicit 3D representations, still produce ineffective sampling in large blank areas. This not only reduces overall performance efficiency but also leads to rendering artifacts in contiguous regions.
## 4 Description of the Application Problem and Employed Multi-Fidelity Models  
### Background of Volume Condensation Due to Mixing  
The application of this method is devoted to characterizing a problem that appears in the automotive sector when a vehicle features an internal combustion engine such as the one depicted in Figure 1. For such turbocharged engines, the use of the so-called Low-Pressure Exhaust Gas Recirculation (LP-EGR) is being widely researched to reduce CO\({}_{2}\), NO\({}_{x}\), and particulate matter emissions [61; 62]. EGR consists of mixing a fraction of exhaust gases (with high humidity content) with fresh air coming from the ambient. As Figure 1 shows, LP-EGR performs this mixture upstream of the compressor, so condensation can happen at certain cold conditions, either at the LP-EGR cooler [63; 64] or at the three-way junction [65; 66]. This possibility of generating condensation upstream of the compressor constitutes one of the main drawbacks of LP-EGR. Indeed, water droplets reaching the impeller will erode its blades and thus reduce its lifetime and performance [41; 67]. In this way, the ability to predict the condensation mass flow rate for the whole engine map would allow automotive engineers to maximize the LP-EGR rate for each working point (and thus minimize CO2, NO_x_ and particulate matter emissions) without exceeding the damage threshold of the impeller, to keep its durability.  
Focusing on the mixing process at three-way junctions, the explanation of how two sub saturated streams can produce condensates is given by the psychometric diagram displayed in Figure 2. Following the LP-EGR junction highlighted in Figure 1, a humid, warm stream of EGR can be blended with a flow of cold ambient air. In these cases, Figure 2 confirms that their mixture can be located in the supersaturation region so that the excess of water until the point \"mix\" lies within the saturation line should be condensed into the form of liquid water.
## 6 Conclusions  
This study proposed a new low-cost methodology for identifying movement pattern anomalies and fall risk in the older adult population, with the potential for impact on various scales. The primary impact is observed in preventive medicine, where this technology enables continuous and timely monitoring of older adults, facilitating early interventions that could significantly reduce the adverse effects associated with falls, and consequently, decrease morbidity and mortality.  
Moreover, the use of deep learning algorithms in this context has proven may be crucial for enhancing the accuracy of fall risk classification. Deep neural networks allow for the processing of large volumes of complex data, identifying patterns that traditional methods cannot capture, resulting in greater sensitivity and specificity. The combination of multiple signals along with deep learning's ability to capture temporal dependencies in the data has significantly optimized the model's performance.  
This methodology also enables the precise evaluation of the effectiveness of therapeutic interventions targeted at each individual, benefiting both patients by personalizing more effective therapeutic strategies, and healthcare systems. Health administrations will be able to manage human and financial resources more efficiently by focusing on individuals who truly require attention, contributing to the reduction of costs associated with unnecessary curative treatments.  
While the results suggest that the deep learning approach may enhance the prediction of fall risk, particularly when multiple signals are combined, it is important to recognize that one study cannot confirm clinical applicability. Multiple studies with similar methodologies are required to replicate these findings before the approach can be considered for clinical trials or large-scale applications. Therefore, we suggest that this approach may enable improved fall risk monitoring in clinical settings, but further research, including real-world trials, is essential to establish its validity and efficacy.  
D.R.C., S.P.Q., A.L.B., D.Q.F., M.R.H. and C.T.T. conceptualization, writing--original draft preparation, visualization, methodology and software. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
This study was conducted in accordance with the Declaration of Helsinki. The research was approved by the Scientific Ethics Evaluation Committee of the Universidad Central de Chile; see registration number 115-2018.  
Each Written informed consent has been obtained from the patient(s) to publish this paper.  
The data presented in this study are available on request from the corresponding author (the data are not publicly available due to privacy restrictions).  
The authors declare no conflicts of interest.  
The following abbreviations are used in this manuscript:  
EP Elderly People  
CoM Center of Mass  
LSTM Long Short-Term Memory  
CNN Convolutional Layers  
Bidir-LSTM Bidirectional Residual Deep Short-Term Memory  
BiLSTM Bidirectional Long Short-Term Memory Network  
HAR Human Activity Recognition
# Therapeutic Potential of Chrysin in Improving Bone Health
## 2 Materials and Methods
### Estimation of 25-OH-D\({}_{3}\) by LC-MS/MS  
The concentration of 25-OH-D\({}_{3}\) in the serum was quantified using the most reliable LC-MS/MS method. The extraction of 25-OH-D\({}_{3}\) from the serum samples was obtained by simple liquid-liquid extraction. Initially, 200 \(\upmu\)L of serum sample was mixed with 25 \(\upmu\)L of internal standard in 200 \(\upmu\)L of methanol and equilibrated for 5 min. Then, 200 \(\upmu\)L of methanol was added, vortexed for 10 s, and allowed to stand for precipitation. Then, 2 mL of n-heptane was added and vortexed for 10 min. The samples were centrifuged at 10,000 rpm for 10 min to separate the organic layer. The organic layer was transferred into clean tubes and evaporated to dryness under nitrogen at room temperature. The prepared samples were reconstituted in 100 \(\upmu\)L of 2 mM ammonium acetate and 0.1% formic acid in 80:20 methanol/water [27,32].  
The 20 \(\upmu\)L of the sample was initially analyzed using an Agilent 1200 series HPLC instrument (Agilent Technologies, Santa Clara, CA, USA) with C18 (250 mm \(\times\) 4.6 mm i.d) column maintained at ambient temperature (30 \({}^{\circ}\)C) coupled to a quadrupole time-of-flight (Q-TOF) mass spectrometer (Q-TOF-LC/MS 6510 classic G6150A, Agilent Technologies, Santa Clara, CA, USA) with a dual ESI as an ion source. The data acquisition was performed under the control of Mass Hunter workstation software. Mobile phase A: 2 mM ammonium acetate, 0.1% formic acid in water, B: 2 mM ammonium acetate, and 0.1% formic acid in methanol was filtered with a 0.45 \(\upmu\)m nylon membrane and pumped with a flow rate of approximately 10 mL/min. The standard calibration curve of 25-OH-D\({}_{3}\) was plotted by selected serial dilutions of 5, 10, 15, 20, and 25 ng/mL. The standard 25-OH-D\({}_{3}\) peak was identified and quantified by comparing the selected fragment ion (\(m/z\) 383.5 \(\rightarrow\) 401.3).
## 1 Introduction
used the CLAHE method for image enhancement and then added a median filter for denoising. Also, the combination ofocal thresholding and Otsu binarization was used for segmenting the veins. The system used an LED array that emits IR of wavelength 850 nm. However, other research has shown that 830 nm is the best wavelength for revealing superficial veins in dark skin [37]. In 2024, [PERSON] et al. [38] explored a new approach to simplifying vein detection for IV procedures using a near-infrared imaging system. The system utilizes a special algorithm that involves image processing techniques to enhance the captured image and highlight veins just beneath the skin's surface. The researchers considered various existing studies in related fields, including finger vein identification, robotic IV assistants, challenges faced inhab settings, and patient experiences with difficult IV insertions. They also explored the potential benefits of remote monitoring for IV therapy, methods to reduce anxiety and pain during IV insertion in children, and even techniques to optimize the near-infraredight used in the system itself, along with advanced image analysis methods to create the clearest possible picture of veins for successful IV placement. However, only 80% of the males and 70% of the females revealed high visible vein structures; in addition, the delay of their proposed system was 4 s.  
Multiple vein finders have been proposed and released to the market; for example, ACCuVein provides simultaneous localization and projection of detected veins; however,their prices range from USD 1800 to USD 7000 per unit [39], which hinders its spread in many medical centers in developing countries. Hence, the alternative solution is making use ofow-cost NIR medical imaging. The contribution of this research is that after an image is captured in an adequate environment, a region of interest is selected to group the detected vein. A selection methodology is applied to supply the robotic machine (to be made in future work) with a veuocation to start the injection process. This paper presents aow-cost embedded system for acquiring NIR images of patients' arms. Also, an improved vein detection algorithm based on CLAHE is proposed. This optimizedow-cost system is aimed to be implemented in intelligent healthcare facilities in order to replace manual vein detection and cannulation. Different computer vision tools were employed, and different approaches were analyzed. Besides extracting different veins in a patient's arm, two novel approaches were proposed to select the best candidate vein for cannulation. This is a base step for performing autonomous cannulation, aiming to avoid human error.
## 2 Materials and Methods
### GPU Implementation of Three NCC Calculation Methods
#### 2.2.2 Block-Matching Using GPU Parallel Computing  
The block-matching algorithm implemented in this study is the classic block-matching algorithm. Because of memory limitation, full 3-D block-matching tracking was first performed in a slice-by-slice manner. Thus, a full displacement vector field for a single slice consists of \(M\times N\) (Axial \(\times\) Lateral) displacement estimation locations; each displacement estimation location obtains one 3-D displacement vector after the block-matching process. Because tracking displacements using the classic block-matching algorithm for each location is independent (i.e., no data dependency and requirements regarding communication), in the CUDA programming structure, the \(M\times N\) thread can be launched through the KERNEL function (see Section 2.2.1). As shown in Figure 1, in order to construct 3-D NCC map for each displacement estimation location, one NCC value needs to be calculated at a specified search location \((\tau_{x},\tau_{y},\tau_{z})\). In the **Step 1** (see Figure 1), given a search range \((A[Axial],B[Lateral],C[Eleational])\), the KERNEL function can start \((M\times N)\times(A\times B\times C)\) CUDA threads to obtain one 3-D NCC map to complete Step 1. Here, \(A=(\tau_{2}-\tau_{1}+1)\), \(B=(\tau_{4}-\tau_{3}+1)\) and \(C=(\tau_{6}-\tau_{5}+1)\).  
In the subsequent **Steps 2** and **3** (see Figure 1), the number of CUDA threads in the KERNEL functions are consistent with the total number of displacement estimation locations \(M\times N\). Basically, each CUDA thread invokes a DEVICE function to search the peak NCC value of the corresponding 3-D NCC map (Step 2). Then, the same DEVICE function uses a quadratic fitting to obtain sub-sample estimates (Step 3) [36].  
In the process of implementation, a few notable strategies were used. First, one-dimensional thread structure was adopted to ensure the consistency of memory access. In other words, we attempted to ensure that adjacent threads read adjacent memory regions and try to satisfy the requirement of coalesced memory access. Second, RF data were stored in TEXTURE memory. Nvidia GPU TEXTURE memory technology can avoid the delay caused by cross-line reading. Third, some important variables (such as axial and lateral search range, tracking kernel size) are stored in GPU constant memory for rapid accesses.
## 6 Discussion and Conclusions  
This paper specified multi-link DCFs for synchronous multi-radio multi-link wireless networks, fully considering the non-STR situation for the multi-link device. Next, 3D Markov Chains are constructed for the multi-link DCFs when two radios are attached to one MLD. Moreover, we present 2D Markov Chain model, which is a reduced model of 3D Markov Chains, and derive throughput analysis for the multi-link DCFs. We investigate the impact of RTS/CTS exchange, the number of stations, the length of PPDU, and the initial CW of MLD on network throughput through the intensive analyses. According to our extensive performance analysis, it is evident that asynchronous multi-link transmission outperforms the other transmission schemes given in the STR case. Besides,  
Figure 15: Sum of saturated throughput depending on initial contention window of MLD, (**a**) when RTS/CTS exchange is off, and (**b**) when RTS/CTS exchange is on.  
asynchronous multi-link transmission should not be used in the non-STR case, especially when the RTS/CTS exchange is disabled. Without synchronizing the multiple channel access, the probability of idle slot times per packet transmission of asynchronous on the non-STR case is much higher than those of the others.  
Overall, MLA-S demonstrates the worst performance based on the analysis because the MLDs' channel access is excessively prioritized so that the conventional single-link devices' on both links can hardly access the wireless medium. As the number of stations increases, MLDs in MLA-S also suffer immmoderate contention, and thus, the throughput of MLA-S dramatically decreases, compared to the throughputs of the other transmission schemes. However, the best multi-link DCF can vary according to the number of MLDs, the number of single-link devices, and the traffic prioritization between the MLD and the single-link devices. In our future work, we will investigate the performance, especially when the traffic is not saturated, to better reflect the dynamic environment.  
Conceptualization, T.S. and T.K.; methodology, T.S.; software, T.S. and T.K.; validation, T.S. and T.K.; formal analysis, T.S. and T.K.; writing--original draft preparation, T.S. and T.K.; writing--review and editing, T.K.; visualization, T.S.; supervision, T.K.; project administration, T.K.; funding acquisition, T.K. All authors have read and agreed to the published version of the manuscript.  
This work was supported in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2019R1G1A1099718) and in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2018R1A4A1025632).  
Not applicable.  
The results presented in this study are provided on a limited basis upon request of the corresponding author. Data may not be made publicly available for reasons of data protection by the relevant organizations.  
We gratefully appreciate the anonymous reviewers' variable reviews and comments.  
The authors declare no conflict of interest.
# A Regionalization Approach Based on the Comparison of Different Clustering Techniques
###### Abstract
The results obtained with Infomap TSA and the federated model provide robust and logical solutions, and K-means++ for k = 5 and spatial contiguity as a third-degree polynomial (from now on, K-means++, k = 5, TSA) align particularly well with the reference regionalization. This alignment improves the reliability of the obtained regions, which highlights the robustness of this method for effective clustering, and for this reason we consider it the most optimal solution.