Abstract
Previously in AtmoHead-2018, we reported joint observations by Telescope Array Surface Detector (TASD), Lightning Mapping Array (LMA), sferic sensor and broadband interferometer of particle ...showers coincident with lightning. These consisted of energetic showers of approximately less than 10 microsecond duration with footprints on the ground of 3-6 kilometers in diameter, originating in the first one to two milliseconds of downward lightning leaders and coincident with high-current processes within the leaders. Scintillator waveform and simulation studies confirmed that these showers must consist primarily of gamma radiation.
On September 11, 2021, atmospheric discharges emitting gamma rays were, for the first time, recorded by a high-speed camera and by lightning detectors on the ground simultaneously. The events were detected by the Telescope Array located in the Utah desert and were filmed by the Phantom v2012 camera, set at an acquisition rate of 40,000 frames per second (fps) in conjunction with the Lightning Mapping Array (LMA), an interferometer, a fast antenna, and the National Lightning Detection Network (NLDN). Results from this study reported the new observation of several events of significantly longer duration and higher uence, bridging the gap between the TASD and satellite-based detections. These events further demonstrate the similarity between the upward and downward TGF varieties and the likelihood of a common origin for their production.
A method for denoising accelerometer data based on the L2‐norm total variation (LTV) algorithm is presented. In order to collect accelerometer data, a wireless accelerometer sensor was developed that ...is directly connected to a central node. By benefiting from the LTV algorithm, the obtained signals from the accelerometer are denoised. The proposed method is tested by denoising in different accelerometer signals and the results are evaluated by signal‐to‐noise ratio and power spectral density functions of the signals. The obtained results reveal that noise reduction has been implemented satisfactorily. Hence, the measurement accuracy of accelerometer signals for the proposed method have improved ∼4–10% than other the three low‐pass filters including Savitzky–Golay, equiripple‐pass‐band and Butterworth.
The way that computing systems digest geographic space is fundamentally different from people's understanding of space. In human discourse, a geographic space is referred to by a place name, and the ...reasoning about a place are based on its characteristics. This is in contrast with computing systems where geographical spaces are handled by the definition of coordinate systems. Hence, when recommending places, a recommendation method that leverages textual content, as a medium of communication among people, can be better understood. In this paper, we use elements of Natural Language Processing (NLP), such as Positive Point-wise Mutual Information (PPMI), Term Frequency - Inverse Document Frequency (TF-IDF), and Multi-Dimensional Scaling (MDS), to infer a conceptual space of the items of a place-based recommender system. By applying a Support Vector Machine (SVM) classifier on the resulting conceptual space, some meaningful directions are extracted. Shannon entropy is used as a measure to identify the directions that imply a valid geographic region. We apply the method on a dataset of advertisement descriptions of rental properties and a dataset of Persian Wikipedia articles. The results showed the proposed method is able to measure the similarity of items in the inferred conceptual space with 88% of accuracy. A comparison with BERT algorithm demonstrates the superiority of the proposed method over the baseline models.
In real-world decision-making problems, we often face multiple criteria that should be considered in the decision process. Also, the collected data are often non-crisp and reported with a degree of ...hesitation. In this study, using intuitionistic fuzzy numbers that can model these non-crisp and hesitant data, we propose a simple yet effective method for solving real-world multi-criteria decision-making problems. We applied our proposed approach to the intuitionistic fuzzy Best-Worst Method, which is one of the famous techniques for solving multi-criteria decision-making problems. However, the proposed method can be easily generalized to the other multi-criteria decision-making methods in intuitionistic fuzzy environments, too. Finally, the ability of the proposed approach to solve these types of problems is shown by an illustrative example.
Blastocystis
is a single-celled intestinal parasite commonly found in humans and a broad range of animals all over the world. In humans, its role in health and disease remains unsettled. The aim of ...our study was to investigate the distribution of
Blastocystis
and
Blastocystis
subtypes (ST) in patients with inflammatory bowel disease (IBD) and control subjects. A total of 71 stool samples were collected from IBD patients, 69 and 2 of whom had ulcerative colitis (UC) and Crohn’s Disease (CD), respectively. Moreover, 166 stool samples from healthy subjects were included as control samples. All stool samples were cultivated, and 550-bp fragments of the small subunit ribosomal RNA gene was amplified from
Blastocystis
-positive cultures. All PCR-positive samples were sequenced.
Blastocystis
was observed in 9 (12.67%) and 35 (21.1%) IBD patients and healthy controls, respectively. There was no statistically significant correlation between IBD and presence of
Blastocystis
(
P
= 0.147). There was a statistically significant correlation between age and
Blastocystis
colonization in the IBD group (
P
< 0.05), but not among healthy controls. No significant correlation between gender and colonization was observed. ST1 and ST3 were obtained from 1 (12.5%) and 7 (87.5%) IBD patients, respectively, while in the healthy control group, subtypes 1, 2, and 3 were found in 14 (40%), 12 (34.28%), and 9 (25.72%), respectively. Phylogenetic analysis showed no variation in the distribution of subtypes nor intra-subtype genetic diversity between samples acquired from IBD patients and healthy controls. This study showed a trend towards a lower prevalence of
Blastocystis
in IBD patients than in control subjects. ST3 sequences isolated from IBD patients and control individuals did not appear to differ genetically.
▸ In dry conditions, fresh Pt–Pd catalyst is more active than fresh Pt catalyst. ▸ Both catalysts permanently lose activity after exposure to 5vol.% water. ▸ For Pt catalyst, the reaction kinetics ...can be modelled using a first order reaction. ▸ For Pt–Pd catalyst, the reaction kinetics can be modelled using an LHHW type rate equation.
A kinetic study was performed over thermally aged and steam-aged Pt and Pt–Pd catalysts to investigate the effect of temperature, and methane and water concentrations on the performance of catalysts in the range of interest for environmental applications. It was found that both catalysts permanently lose a large portion of their initial activity as result of exposure to 5vol.% water in the reactor feed. Empirical power-law and LHHW type of rate equations were proposed for methane combustion over Pt and Pt–Pd catalysts respectively. Optimization was used to determine the parameters of the proposed rate equations using the experimental results. The overall reaction orders of one and zero in methane and water concentration was found for stabilized steam-aged Pt catalyst in the presence and absence of water. The apparent self-inhibition effect caused by methane over Pt–Pd catalyst in the absence of water was associated with the inhibiting effect of water produced during the combustion of methane. A significant reversible inhibition effect was also observed over steam-aged Pt–Pd catalyst when 5vol.% water vapor was added to the reactor feed stream. A significant reduction in both activity and activation energy was observed above temperatures of approximately 550°C for steam-aged Pt–Pd catalyst in the presence of water (the activation energy dropped from a value of 72.6kJ/mol to 35.7kJ/mol when temperature exceeded 550°C).
The study investigated the effects of feeding mixtures of alfalfa (AF) and sweet sorghum (SS) at different ratios of silages in terms of the physiological status of blood and rumen, and rumen ...microbiota in lambs. A total of 30 four-month-old male Karakul lambs with 25.5 ± 1.4 kg mean initial body weight were randomly allocated to five groups, with six lambs in each group. Five experimental diets containing 40% of one of the five AF−SS mixed silages (containing 0%, 20%, 40%, 60%, and 80% AF on a fresh weight basis, respectively) and 60% of other ingredients were formulated. Overall, the results showed that the mixed silage with more AF tended to increase serum antioxidant capacity, dry matter (DM) intake, and rumen fermentation metabolites. The AF−SS mixed silages containing AF at 60% and 80% caused a significant linear increase (p < 0.05) in the activity of total antioxidant capacity. The superoxide dismutase in the Karakul lamb responded with significant linear and quadratic increases (p < 0.01) as the ratio of AF was increased in the AF−SS mixed silages. Feeding diets with AF in silage mixtures at the ratio of 60% significantly increased (p < 0.05) the concentration of ruminal total volatile fatty acids (tVFA), acetate, and ammonia-N. However, no statistical significance (p > 0.05) was found in the alpha diversity of rumen microbes among the tested groups (p > 0.05). Principal coordinates analysis could clearly discriminate the differences between the five groups (p = 0.001). The relative abundance of Firmicutes in the rumen were significantly higher with AF at 40% in the AF−SS silage-based diet than those with AF at 0%, and 20% ratios. The abundance of Ruminococcus_albus had a significant linear increase (p < 0.05), as the ratio of AF in the AF−SS mixed silages was increased. In conclusion, the best beneficial effect on the physiological status of the blood and rumen, DM intake, and rumen microbiota in lambs came from those that consumed the diet containing the AF−SS mixed silage with 60% AF.
This work proposes an algorithm besides output feedback linearization method for controlling a wheeled mobile robot with two manipulators. To control such a mobile robot, three desired trajectories ...(or fixed points for regulation) are needed: two for the arms and one for the base. Improper choice in base path leads to singularity, low performance and failure. To prevent singularities and to attain a smooth motion, an algorithm is introduced as a local path planning process for the base. It consists of two parts which helps the robot to maintain the desired configuration. The first part of the algorithm mainly focuses on the position and orientation of the base in future time based on the arms configuration, and the second part adjusts the movement of the arms for obtaining a consistent motion. This maintenance reduces and preserves the norm of applied torques, which consequently leads to an increase in the performance of the robot and its dynamic load carrying capacity (DLCC). Also, it is no longer required to define a trajectory or an end point for the base movement since they will be calculated automatically by the algorithm.
