Miracle-dz/UniFAR-FTUs huggingface dataset:
Frequency domain least-squares reverse time migration with a modified scattering-integral approach

Summary Least-squares reverse time migration (LSRTM) is an iterative inversion-based imaging process, which can suppress migration artefacts, balance reflector amplitudes, and enhance spatial resolution compared with standard reverse time migration (RTM). The widely accepted approach for gradient calculation in LSRTM is the adjointstate method, where the forward propagated source wavefields are zero-lag cross-correlated with the backpropagated receiver wavefields. In this study, we propose a practical alternative for implementing frequency domain RTM (FRTM) and LSRTM (FLSRTM) with a modified scattering-integral approach. The gradient of the misfit function with respect to model parameters is formulated as matrix-vector products, which are calculated with vector operations through the accumulation of decomposed vector-scalar products without explicitly building the kernel matrix. With such a matrix-based scattering-integral approach, we can guarantee that the migration operator is the exact adjoint (conjugate transpose) of the forward Born modeling operator while with reduced memory requirement. At the meantime, the Gauss-Newton normal equation is iteratively solved with a matrix-free conjugate gradient algorithm. The Hessian-vector products are calculated based on a demigration/migration procedure, which are implemented with two nested kernel-vector products. Thus, no additional forward simulations are required any more. The numerical example proves the feasibility of our method.
Semantic closed-loop based visual mapping algorithm for automated valet parking

Simultaneous localization and mapping (SLAM) is one of the core technologies to realize automated valet parking (AVP). Currently, advanced visual feature-based SLAM systems suffer from feature extraction failure and tracking loss due to the constraints of textureless scenes, unclear illumination, and dynamic conditions. To address these problems, this paper proposes a visual SLAM algorithm based on a semantic closed-loop detection algorithm using surround-view cameras and inertial measurement units (IMU) as sensors. The algorithm combines semantic features and the idea of inverse index to improve the traditional keyframes selection methods and the closed-loop detection algorithms, effectively avoiding the tedious and complicated feature point matching and improving the computational efficiency of the computer. Experiments show that the algorithm in this paper achieves better results in terms of precision and recall, absolute trajectory error (ATE), and relative pose error (RPE), and can meet the demand for SLAM and subsequent navigation in indoor parking lots.
Complete Second Order Linear Differential Equations In Hilbert Spaces

Thank you very much for downloading complete second order linear differential equations in hilbert spaces. Maybe you have knowledge that, people have look numerous times for their chosen novels like this complete second order linear differential equations in hilbert spaces, but end up in harmful downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they are facing with some malicious virus inside their laptop.
A Multi-Configuration Track-Legged Humanoid Robot for Dexterous Manipulation and High Mobility: Design and Development

Various applications (e.g., disaster response) put forward higher requirements for the capabilities of robots. However, to date, few platforms can be compatible with the required mobility, stability and dexterity. A major challenge is mobile stability may severely limit the variety of manipulation skills. To tackle the issue, this paper presents a new track-legged humanoid robot, Dexbot, aiming to achieve both dexterity and mobility simultaneously. Dexbot is composed of a versatile humanoid upper body and a track-legged mobile platform, with a total of 56 active DOFs and about 10 transformable configurations, allowing for precise manipulation and traversal of various complex environments. Additionally, it features a lightweight and highly integrated design, with notable dexterity, strength and mobility in its class. Herein, this paper reports a brief overview of each subsystem, focusing on the robotic structure, system architecture, and some applied strategies of capabilities development. Lastly, some essential performances are demonstrated through a series of experiments.
Antiviral Activity of Acetylsalicylic Acid against Bunyamwera Virus in Cell Culture

The Bunyavirales order is a large group of RNA viruses that includes important pathogens for humans, animals and plants. With high-throughput screening of clinically tested compounds we have looked for potential inhibitors of the endonuclease domain of a bunyavirus RNA polymerase. From a list of fifteen top candidates, five compounds were selected and their antiviral properties studied with Bunyamwera virus (BUNV), a prototypic bunyavirus widely used for studies about the biology of this group of viruses and to test antivirals. Four compounds (silibinin A, myricetin, L-phenylalanine and p-aminohippuric acid) showed no antiviral activity in BUNV-infected Vero cells. On the contrary, acetylsalicylic acid (ASA) efficiently inhibited BUNV infection with a half maximal inhibitory concentration (IC50) of 2.02 mM. In cell culture supernatants, ASA reduced viral titer up to three logarithmic units. A significant dose-dependent reduction of the expression levels of Gc and N viral proteins was also measured. Immunofluorescence and confocal microscopy showed that ASA protects the Golgi complex from the characteristic BUNV-induced fragmentation in Vero cells. Electron microscopy showed that ASA inhibits the assembly of Golgi-associated BUNV spherules that are the replication organelles of bunyaviruses. As a consequence, the assembly of new viral particles is also significantly reduced. Considering its availability and low cost, the potential usability of ASA to treat bunyavirus infections deserves further investigation.
Rapid Elisa from Whole Blood in A Microcentrifuge Tube

Herein, we describe an enzyme-linked immunosorbent assay (ELISA) technique carried out in a polypropylene microcentrifuge tube preactivated by a photolinker, 1-fluoro-2-nitro-4-azidobenzene (FNAB) by a photochemical reaction. Immobilization of capture molecule (antibody) and BSA-blocking are carried out in the tube by ultrasound waves in a sonicator bath in 10 min for each step. Around one drop (100 μl) of blood is directly collected into the tube. By the time, the sample reaches laboratory (nearly 1 h), the analyte present in blood binds to the capture molecule already present in the tube. That means only one step (antibody-conjugate binding step) has to be carried out requiring only 10 min by ultrasound waves. The advantage of the method is that sample collection and testing can be done in the same tube and more importantly without the need of getting serum by a time consuming process. Also, time is saved for Ag-Ab binding step making the procedure more rapid.
Design of Ultra-Wideband Doherty Power Amplifier Using a Modified Combiner Integrated with Complex Combining Impedance

To be compatible with future wireless communication systems, it is very necessary to extend the bandwidth of the Doherty power amplifier (DPA). In this paper, a modified combiner integrated with a complex combining impedance is adopted to enable an ultra-wideband DPA. Meanwhile, a comprehensive analysis is performed on the proposed method. It is illustrated that the proposed design methodology can provide power amplifier (PA) designers with more freedom in implementing ultra-wideband DPAs. As a concept of proof, a DPA working over 1.2–2.8 GHz (a relative bandwidth of 80%) is designed, fabricated and measured in this work. Experimental results showed that the fabricated DPA delivers a saturation output power of 43.2–44.7 dBm with a gain of 5.2–8.6 dB. Meantime, the fabricated DPA achieves a saturation drain efficiency (DE) of 44.3–70.4% and a 6 dB back-off DE of 38.7–57.6%.
High-throughput exploration of thermoelectric and mechanical properties of amorphous NbO2 with transition metal additions

To increase the thermoelectric efficiency and reduce the thermal fatigue upon cyclic heat loading, alloying of amorphous NbO2 with all 3d and 5d transition metals has systematically been investigated using density functional theory. It was found that Ta fulfills the key design criteria, namely, enhancement of the Seebeck coefficient and positive Cauchy pressure (ductility gauge). These quantum mechanical predictions were validated by assessing the thermoelectric and elastic properties on combinatorial thin films, which is a high-throughput approach. The maximum power factor is 2813 μW m−1 K−2 for the Ta/Nb ratio of 0.25, which is a hundredfold increment compared to pure NbO2 and exceeds many oxide thermoelectrics. Based on the elasticity measurements, the consistency between theory and experiment for the Cauchy pressure was attained within 2%. On the basis of the electronic structure analysis, these configurations can be perceived as metallic, which is consistent with low electrical resistivity and ductil.
First Study on profiling of gut microbiome in wild and captive Sumatran orangutans (Pongo abelii)

Background and Aim: Orangutans are an “umbrella species” for conserving tropical forests in Sumatra and Kalimantan. There are remarkable changes between the gut microbiomes of wild and captive Sumatran orangutans. This study aimed to profile gut microbiota of wild and captive Sumatran orangutans. Materials and Methods: Nine fecal samples collected from wild orangutans and nine fecal samples collected from captive orangutans were divided into three replicates. Each replicate randomly combined three pieces and were analyzed on the Illumina platform. A bioinformatics study of 16S rRNA according to Qiime2 (Version 2021.4) and microbiome profiling analysis was conducted. Results: The relative abundance of different microbial taxa varied significantly between wild and captive Sumatran orangutans. Among the operational taxonomic units, various proportions of Firmicutes, Proteobacteria, Bacteroidetes, Euryarchaeota, Acidobacteria, Actinobacteria and Verrucomicrobia predominated. Solobacterium was found only in 19% of captive orangutans. Methanobrevibacter was identified to be prevalent among wild orangutans (16%). Analysis of the core microbiome from the combined wild and captive data revealed seven species as cores. According to linear discriminant analysis effect size, Micrococcus luteus, Bacteroidescaccae, Lachnospiraceae bacterium, Ruthenibacterium lactatiformans, Haemophilus haemolyticus, and Chishuiella spp. were microbiome biomarkers in captive orangutans, whereas Roseburia inulinivorans, Collinsella aerofaciens, Oscillibacter spp. , and Eubacterium hallii were microbiome biomarkers in wild orangutans. Conclusion: There were differences in the microbiome biomarkers of wild and captive Sumatran orangutans. This study is important for understanding the role of gut bacteria in the health of Sumatran orangutans.
Multi-agent based scheduling method for tandem automated guided vehicle systems

The way a AGV in each zone in tandem AGV (Automated Guided Vehicles) systems handles the local request for transport while schedules effectively the global request for transport involving the pickup/delivery operation at the transfer point by cooperating a AGV in other zone, affect the traveling time of the AGV (and thus energy consumption), as well as the waiting time of each node in the system. So far, almost all studies on tandem AGV systems focus on the optimal number of partitioned zones (and thus the number of AGVs), the optimal location of nodes into zones, the optimal location of transfer points between each two zones, the design of AGV’s direction to minimize the total handling flow or the traveling distance of AGV in each zone. This study presented a novel scheduling approach to effectively deal with global and local request by minimizing the total traveling time within the individual zone and the waiting time at the transfer points between zones based on the cooperating control of multi-agent. The proposed approach is verified at the AGV system for book printing process as the real-world experiment and it is showed that the scheduling for multi-agent based tandem AGV system is effective
Unexpected Procedure Difficulties Increasing the Complexity of Transvenous Lead Extraction: The Single Centre Experience with 3721 Procedures

Background: Transvenous lead extraction (TLE) should be completed, even when facing difficulties which have yet to be described. The aim was to explore unexpected TLE obstacles (the circumstances of the occurrence and influence on TLE outcome). Methods: The retrospective analysis of a single centre database containing 3721 TLEs. Results: Unexpected procedure difficulties (UPDs) occurred in 18.43% of cases (singles in 12.20% of cases and multiples in 6.26% of cases). These included blockages in the lead venous approach in3.28% of cases, functional lead dislodgement in 0.91% of cases, and loss of broken lead fragment in 0.60% of cases. All of them, including implant vein—in 7.98% of cases, lead fracture during extraction—in 3.84% of cases, and lead-to-lead adherence—in 6.59% of cases, Byrd dilator collapse—in 3.41% of cases, including the use of an alternative prolonged the procedure but had no influence on long-term mortality. Most of the occurrences were associated with lead dwell time, younger patient age, lead burden, and poorer procedure effectiveness and complications (common cause). However, some of the problems seemed to be related to cardiac implantable electronic devices (CIED) implantation and the subsequent lead management strategy. A more complete list of all tips and tricks is still required. Conclusions: (1) The complexity of the lead extraction procedure combines both prolonged procedure duration and the occurrence of lesser-known UPDs. (2) UPDs are present in nearly one fifth of the TLE procedures, and can occur simultaneously. (3) UPDs, which usually force the extractor to expand the range of techniques and tools, should become part of the training in transvenous lead extraction.
CONTESTING THE COVID-19 CONSENSUS: CONNECTIVE ACTION OF PSEUDOANONYMOUS ACCOUNTS ON FINNISH TWITTER

Recent years have witnessed invigorated debate about the contradictions of identity-concealing public participation and its influence on democratic deliberation and policy-making. Some have documented the exploitation of misrepresented identities for manipulation, including the manufacturing and disrupting of political discourses. Others argue that pseudonymous speech fosters less conformist and more secure public spaces for critical social commentary and political activism. In this study, we extend this dichotomy by approaching pseudoanonymous online action as connective action; as focused and communicative political activism aimed to contest the authorities’ Covid-19 response during the pandemic in Finland. Our empirical analysis uses the historical Twitter data, over 4.2 million tweets, by pseudoanonymous Twitter accounts predominantly tweeting about Covid-19 (n = 229). Using mention and retweet networks combined with profile metrics and qualitative reading of tweets filtered through the network analysis, we explore the networked activity of these accounts, the strategies they have employed to contest authorities, and their connections to political actors and other more organized forms of mobilization around Covid-19. The preliminary analysis highlights the prominence of these accounts in Covid-19 related Twitter discussions, along with their distinct behavioural features. Pseudoanonymous accounts average shorter lifespans and higher deactivation rates. Some accounts have transitioned from named accounts towards identity-concealing action during the observation period. Further, our analysis reveals a symbiotic relationship between the pseudoanonymous accounts and the established Covid-19 movements. We argue that pseudoanonymous participation is an increasingly emblematic form of connective action afforded by social media platforms, particularly fitted to undermine the legitimacy of authorities.
Long-Term Impact of COVID-19 on Heart Rate Variability: A Systematic Review of Observational Studies

Coronavirus disease 2019 (COVID-19) sequelae (or long COVID) has become a clinically significant concern. Several studies have reported the relationship between heart rate variability (HRV) parameters and COVID-19. This review investigates the long-term association between COVID-19 and HRV parameters. Four electronic databases were searched up to 29 July 2022. We included observational studies comparing HRV parameters (measurement durations: 1 min or more) in participants with and without a history of COVID-19. We used assessment tools developed by the National Heart, Lung, and Blood Institute group to evaluate the methodological quality of included studies. Eleven cross-sectional studies compared HRV parameters in individuals who recovered from acute COVID-19 infection to controls (n = 2197). Most studies reported standard deviation of normal-to-normal intervals (SDNN) and root mean square of the successive differences. The methodological quality of the included studies was not optimal. The included studies generally found decreased SDNN and parasympathetic activity in post-COVID-19 individuals. Compared to controls, decreases in SDNN were observed in individuals who recovered from COVID-19 or had long COVID. Most of the included studies emphasized parasympathetic inhibition in post-COVID-19 conditions. Due to the methodological limitations of measuring HRV parameters, the findings should be further validated by robust prospective longitudinal studies.
Spot Detection for Laser Sensors Based on Annular Convolution Filtering

Spot detection has attracted continuous attention for laser sensors with applications in communication, measurement, etc. The existing methods often directly perform binarization processing on the original spot image. They suffer from the interference of the background light. To reduce this kind of interference, we propose a novel method called annular convolution filtering (ACF). In our method, the region of interest (ROI) in the spot image is first searched by using the statistical properties of pixels. Then, the annular convolution strip is constructed based on the energy attenuation property of the laser and the convolution operation is performed in the ROI of the spot image. Finally, a feature similarity index is designed to estimate the parameters of the laser spot. Experiments on three datasets with different kinds of background light show the advantages of our ACF method, with comparison to the theoretical method based on international standard, the practical method used in the market products, and the recent benchmark methods AAMED and ALS.
ON THE CONVERGENCE ANALYSIS OF GRAVITATIONAL SEARCH ALGORITHM

Gravitational search algorithm (GSA) is one of the newest swarm based optimization algorithms, which has been inspired by the Newtonian laws of gravity and motion. GSA has empirically shown to be an efficient and robust stochastic search algorithm. Since introducing GSA a convergence analysis of this algorithm has not yet been developed. This paper introduces the first attempt to a formal convergence analysis of the standard gravitational search algorithm which involves with randomness and time varying parameters. In this analysis the behavior of GSA on the facet of mass interaction is considered. The paper provides a formal proof that each object converges to a stable point. K eyw ord s: Analysis of algorithms, Heuristic optimization, Swarm intelligence,
Bandwidth-Reconfigurable Coaxial Bandpass Filter With Multioctave Tuning Using a Single Element

A bandwidth (BW) tunable coaxial-loaded waveguide filter is presented in this letter based on a novel concept using a single tuning element. The operation principle relies on the rotation of coaxial resonators with respect to fixed irises in order to change the inter-resonator (IR) coupling strengths that control the BW. This mechanism features multioctave tuning while maintaining a fixed operating frequency and a stable unloaded quality factor with only one rotary post. Furthermore, the filter can be switched off by using the same tuning mechanism. A prototype is manufactured and measured to verify the proposed filter. The measured results demonstrate multioctave BW tunability from 12 to 83 MHz (tuning ratio > 6.9:1), promoting the technique for multistandard communication systems and applications.
Sonication-assisted liquid exfoliation and size-dependent properties of magnetic two-dimensional α-RuCl3

Originating from the hexagonal arrangement of magnetic ions in the presence of strong spin orbit coupling, α-RuCl3 is considered as model system for the Kitaev-Heisenberg model. While the magnetic properties of α-RuCl3 have been studied in bulk single crystals or micromechanically-exfoliated nanosheets, little is known about the nanosheets’ properties after exfoliation by techniques suitable for mass production such as liquid phase exfoliation (LPE). Here, we demonstrate sonication-assisted LPE on α-RuCl3 single crystals in an inert atmosphere. Coupled with centrifugation-based size selection techniques, the accessible size- and thickness range is quantified by statistical atomic force microscopy. Individual nanosheets obtained after centrifugation-based size selection are subjected to transmission electron microscopy to confirm their structural integrity after the exfoliation. The results are combined with bulk characterisation methods, including Raman and x-ray photoelectron spectroscopy, and powder diffraction experiments to evaluate the structural integrity of the nanosheets. We report changes of the magnetic properties of the nanomaterial with nanosheet size, as well as photospectroscopic metrics for the material concentration and average layer number. Finally, a quantitative analysis on environmental effects on the nanomaterial integrity is performed based on time and temperature dependent absorbance spectroscopy revealing a relatively slow decay (half-life of ∼2000 h at 20 °C), albeit with low activation energies of 6–20 kJ mol−1.
Total Phenolic and Total Flavonoid Content, Individual Phenolic Compounds and Antioxidant Activity in Sweet Rowanberry Cultivars

Sweet rowanberry and its cultivars represent a less-known fruit species with significant antioxidant activity, mostly promoted by polyphenolic compounds. This paper examined seven Sorbus cultivars and evaluated their total polyphenolic and flavonoid content, as well as the content of individual polyphenolic compounds from the group of phenolic acids and flavonoids. It also determined their antioxidant activity using DPPH, ACW and ACL. Furthermore, to reflect the distribution of the contribution to antioxidant activity, correlations between antioxidant activity and the contents of ascorbic acid, vitamin E and individual phenolic compounds were established. The highest total phenolic content of 8307.4 mg kg−1 was determined in ‘Granatina’, with the main contribution of phenolic acid content of 7001.7 mg kg−1 and a significantly lower total flavonoid content of 1304.6 mg kg−1. Flavanols represented the most abundant group of flavonoids, with catechin being the second most frequent flavanol with the highest content of 633.67 mg kg−1 in ‘Granatina’. Flavonols were represented by rutin and quercetin. ‘Businka’ displayed a significant vitamin E content of 4.77 mg kg−1, and ‘Alaja Krupnaja’ had the highest vitamin C level of 7.89 g kg−1. These results emphasize their potential health and nutritional benefits and, thus, their promising and valuable role in the food processing industry.