2,924 research outputs found
DEVELOPMENT OF A K-NN MODEL TO PREDICT THE POLARITY OF KOREAN GAME REVIEW COMMENTS
The purpose of this paper is to develop the machine learning model to evaluate game software in quantitative scale using opinion mining with the review comments which are provided by users in Korean. To do this, we first decompose the review comments into a lot of meaningful morphemes, and second construct a dictionary for opinion mining. Third, we develop a k-NN model to predict the polarity of review comment. Finally, we predict the polarity for each review comment which is included in validation data set by the model. The experimental results of the developed model are performed by the model which is implemented by JAVA and R language
Optimization of magnetic flux density for fast MREIT conductivity imaging using multi-echo interleaved partial fourier acquisitions
BACKGROUND: Magnetic resonance electrical impedance tomography (MREIT) has been introduced as a non-invasive method for visualizing the internal conductivity and/or current density of an electrically conductive object by externally injected currents. The injected current through a pair of surface electrodes induces a magnetic flux density distribution inside the imaging object, which results in additional magnetic flux density. To measure the magnetic flux density signal in MREIT, the phase difference approach in an interleaved encoding scheme cancels out the systematic artifacts accumulated in phase signals and also reduces the random noise effect by doubling the measured magnetic flux density signal. For practical applications of in vivo MREIT, it is essential to reduce the scan duration maintaining spatial-resolution and sufficient contrast. In this paper, we optimize the magnetic flux density by using a fast gradient multi-echo MR pulse sequence. To recover the one component of magnetic flux density B(z), we use a coupled partial Fourier acquisitions in the interleaved sense. METHODS: To prove the proposed algorithm, we performed numerical simulations using a two-dimensional finite-element model. For a real experiment, we designed a phantom filled with a calibrated saline solution and located a rubber balloon inside the phantom. The rubber balloon was inflated by injecting the same saline solution during the MREIT imaging. We used the multi-echo fast low angle shot (FLASH) MR pulse sequence for MRI scan, which allows the reduction of measuring time without a substantial loss in image quality. RESULTS: Under the assumption of a priori phase artifact map from a reference scan, we rigorously investigated the convergence ratio of the proposed method, which was closely related with the number of measured phase encode set and the frequency range of the background field inhomogeneity. In the phantom experiment with a partial Fourier acquisition, the total scan time was less than 6 seconds to measure the magnetic flux density B(z) data with 128×128 spacial matrix size, where it required 10.24 seconds to fill the complete k-space region. CONCLUSION: Numerical simulation and experimental results demonstrated that the proposed method reduces the scanning time and provides the recovered B(z) data comparable to what we obtained by measuring complete k-space data
Improving Position Estimation of the RFID Tag Floor Localization with Multiple Recognition Ranges
Robustness of the intrinsic anomalous Hall effect in Fe3GeTe2 to a uniaxial strain
Fe3GeTe2 (FGT), a ferromagnetic van der Waals topological nodal line
semimetal, has recently been studied. Using first-principles calculations and
symmetry analysis, we investigate the effect of a uniaxial tensile strain on
the nodal line and the resultant intrinsic anomalous Hall effect (AHE). Our
results reveal their robustness to the in-plane strain. Moreover, the intrinsic
AHE remains robust even for artificial adjustment of the atomic positions
introduced to break the crystalline symmetries of FGT. When the spin-orbit
coupling is absent, the nodal line degeneracy remains intact as long as the
inversion symmetry or the two-fold screw symmetry is maintained, which reveal
that the nodal line may emerge much more easily than previously predicted. This
strong robustness is surprising and disagrees with the previous experimental
report [Y. Wang et al., Adv. Mater. 32, 2004533 (2020)], which reports that a
uniaxial strain of less than 1 % of the in-plane lattice constant can double
the anomalous Hall resistance. This discrepancy implies that the present
understanding of the AHE in FGT is incomplete. The possible origins of this
discrepancy are discussed.Comment: 7 pages, 3 figure
Role of interleukin-10 in endochondral bone formation in mice: Anabolic effect via the bone morphogenetic protein/Smad pathway
Objective: Interleukin-10 (IL-10) is a pleiotropic immunoregulatory cytokine with a chondroprotective effect that is elevated in cartilage and synovium in patients with osteoarthritis. However, the role of IL-10 during endochondral bone formation and its mechanism of action have not been elucidated. Methods: IL-10-/- mice and IL-10-treated tibial organ cultures were used to study loss and gain of IL-10 functions, respectively, during endochondral bone formation. Primary chondrocytes from the long bones of mouse embryos were cultured with and without IL-10. To assess the role of IL-10 in chondrogenic differentiation, we conducted mesenchymal cell micromass cultures. Results: The lengths of whole skeletons from IL-10-/- mice were similar to those of their wild-type littermates, although their skull diameters were smaller. The tibial growth plates of IL-10-/- mice showed shortening of the proliferating zone. Treatment with IL-10 significantly increased tibial lengths in organ culture. IL-10 also induced chondrocyte proliferation and hypertrophic differentiation in primary chondrocytes in vitro. Mechanistically, IL-10 activated STAT-3 and the Smad1/5/8 and ERK-1/2 MAP kinase pathways and induced the expression of bone morphogenetic protein 2 (BMP-2) and BMP-6 in primary chondrocytes. Furthermore, the blocking of BMP signaling attenuated the IL-10-mediated induction of cyclin D1 and RUNX-2 in primary chondrocytes and suppressed Alcian blue and alkaline phosphatase staining in mesenchymal cell micromass cultures. Conclusion: These results indicate that IL-10 acts as a stimulator of chondrocyte proliferation and chondrogenic or hypertrophic differentiation via activation of the BMP signaling pathway. © 2013, American College of Rheumatology
Transcriptional Regulator TonEBP Mediates Oxidative Damages in Ischemic Kidney Injury
TonEBP (tonicity-responsive enhancer binding protein) is a transcriptional regulator whose expression is elevated in response to various forms of stress including hyperglycemia, inflammation, and hypoxia. Here we investigated the role of TonEBP in acute kidney injury (AKI) using a line of TonEBP haplo-deficient mice subjected to bilateral renal ischemia followed by reperfusion (I/R). In the TonEBP haplo-deficient animals, induction of TonEBP, oxidative stress, inflammation, cell death, and functional injury in the kidney in response to I/R were all reduced. Analyses of renal transcriptome revealed that genes in several cellular pathways including peroxisome and mitochondrial inner membrane were suppressed in response to I/R, and the suppression was relieved in the TonEBP deficiency. Production of reactive oxygen species (ROS) and the cellular injury was reproduced in a renal epithelial cell line in response to hypoxia, ATP depletion, or hydrogen peroxide. The knockdown of TonEBP reduced ROS production and cellular injury in correlation with increased expression of the suppressed genes. The cellular injury was also blocked by inhibitors of necrosis. These results demonstrate that ischemic insult suppresses many genes involved in cellular metabolism leading to local oxidative stress by way of TonEBP induction. Thus, TonEBP is a promising target to prevent AKI
The Effect of Target Height on the Trunk, Pelvis, and Thigh Kinematics in the Taekwondo Roundhouse Kick
Short-Term Effects of Ginkgo biloba Extract on Peripapillary Retinal Blood Flow in Normal Tension Glaucoma
PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG).
METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed.
RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area.
CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.ope
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