3,760 research outputs found
Higgs Inflation and the Refined dS Conjecture
The refined de Sitter derivative conjecture provides constraints to
potentials that are low energy effective theories of quantum gravity. It can
give direct bounds on inflationary scenarios and determine whether the theory
is in the Landscape or the Swampland. We consider the `Higgs inflation'
scenario taking the refined de Sitter derivative conjecture into account.
Obtaining the critical lines for the potential, we find a conjecture parameter
space in which the `Higgs inflation' is to be in the Landscape. Comparing with
the model independent observational bounds from recent data we find that the
observational bounds represent the Higgs inflation can be in the Landscape.Comment: 5 pages, 4 figures, Version to appear in PL
TED Talk Recommender Using Speech Transcripts
Nowadays, online video platforms mostly recommend related videos by analyzing
user-driven data such as viewing patterns, rather than the content of the
videos. However, content is more important than any other element when videos
aim to deliver knowledge. Therefore, we have developed a web application which
recommends related TED lecture videos to the users, considering the content of
the videos from the transcripts. TED Talk Recommender constructs a network for
recommending videos that are similar content-wise and providing a user
interface.Comment: 3 page
Erratum to “Economic Analysis for Setting Appropriate Repair Cycles on the Fixed Materials and Facilities in the Public Rental Housing”
Currently, repair and maintenance cycles that follow the completion of construction facilities lead to the necessitation of subsequent data on the analysis of study and plan for maintenance. As such, an index of evaluation was drafted and a plan of maintenance cycle was computed using the investigation data derived from surveying target housing units in permanent rental environmental conditions, with a minimum age of 20 years, and their maintenance history. Optimal maintenance and replacement methods were proposed based on this data. Economic analysis was conducted through the Risk-Weighted Life Cycle Cost (RWLCC) method in order to determine the cost analysis of maintenance life cycle methods used for repair. Current maintenance cycle methods that have been used for 20 years were also compared with alternative maintenance cycles
Charge Transfer Induced Molecular Hole Doping into Thin Film of Metal-Organic-Frameworks
Despite the highly porous nature with significantly large surface area, metal
organic frameworks (MOFs) can be hardly used in electronic, and optoelectronic
devices due to their extremely poor electrical conductivity. Therefore, the
study of MOF thin films that require electron transport or conductivity in
combination with the everlasting porosity is highly desirable. In the present
work, thin films of Co3(NDC)3DMF4 MOFs with improved electronic conductivity
are synthesized using layer-by-layer and doctor blade coating techniques
followed by iodine doping. The as-prepared and doped films are characterized
using FE-SEM, EDX, UV/Visible spectroscopy, XPS, current-voltage measurement,
photoluminescence spectroscopy, cyclic voltammetry, and incident photon to
current efficiency measurements. In addition, the electronic and semiconductor
property of the MOF films are characterized using Hall Effect measurement,
which reveals that in contrast to the insulator behavior of the as-prepared
MOFs, the iodine doped MOFs behave as a p-type semiconductor. This is caused by
charge transfer induced hole doping into the frameworks. The observed charge
transfer induced hole doping phenomenon is also confirmed by calculating the
densities of states of the as-prepared and iodine doped MOFs based on density
functional theory. Photoluminescence spectroscopy demonstrate an efficient
interfacial charge transfer between TiO2 and iodine doped MOFs, which can be
applied to harvest solar radiations.Comment: Main paper (19 pages, 6 figures) and supplementary information (15
pages, 10 figures), accepted in ACS Appl. Materials & Interface
CropCat: Data Augmentation for Smoothing the Feature Distribution of EEG Signals
Brain-computer interface (BCI) is a communication system between humans and
computers reflecting human intention without using a physical control device.
Since deep learning is robust in extracting features from data, research on
decoding electroencephalograms by applying deep learning has progressed in the
BCI domain. However, the application of deep learning in the BCI domain has
issues with a lack of data and overconfidence. To solve these issues, we
proposed a novel data augmentation method, CropCat. CropCat consists of two
versions, CropCat-spatial and CropCat-temporal. We designed our method by
concatenating the cropped data after cropping the data, which have different
labels in spatial and temporal axes. In addition, we adjusted the label based
on the ratio of cropped length. As a result, the generated data from our
proposed method assisted in revising the ambiguous decision boundary into
apparent caused by a lack of data. Due to the effectiveness of the proposed
method, the performance of the four EEG signal decoding models is improved in
two motor imagery public datasets compared to when the proposed method is not
applied. Hence, we demonstrate that generated data by CropCat smooths the
feature distribution of EEG signals when training the model.Comment: 4 pages, 1 tabl
Interferometric Monitoring of Gamma-ray Bright AGNs: 4C +28.07 and its Synchrotron Self-absorption Spectrum
We present the analysis results of the simultaneous multifrequency
observations of the blazar 4C +28.07. The observations were conducted by the
Interferometric Monitoring of Gamma-ray Bright Active Galactic Nuclei (iMOGABA)
program, which is a key science program of the Korean Very Long Baseline
Interferometry (VLBI) Network (KVN). Observations of the iMOGABA program for 4C
+28.07 were conducted from 16 January 2013 (MJD 56308) to 13 March 2020 (MJD
58921). We also used {\gamma}-ray data from the Fermi Large Array Telescope
(Fermi-LAT) Light Curve Repository. We divided the iMOGABA data and the
Fermi-LAT data into five periods from 0 to 4, according to the prosody of the
22 GHz data and the presence or absence of the data. In order to investigate
the characteristics of each period, the light curves were plotted and compared.
However, a peak was observed earlier than the period of a strong {\gamma}-ray
flare at 43-86 GHz in period 3 (MJD 57400-58100). Therefore, we assumed that
the minimum total CLEANed flux density for each frequency was quiescent flux
(Sq), with the variable flux (Svar) obtained by subtracting Sq from the values
of the total CLEANed flux density. We then compared the variability of the
spectral indices ({\alpha}) between adjacent frequencies. Most notably,
{\alpha}22-43 showed optically thick spectra in the absence of a strong
{\gamma}-ray flare, and when the flare appeared, {\alpha}22-43 became optically
thinner. In order to find out the characteristics of the magnetic field in the
variable region, the magnetic field strength in the synchrotron self-absorption
(BSSA) and the equipartition magnetic field strength (Beq) were obtained. We
found that BSSA is largely consistent with Beq within the uncertainty, implying
that the SSA region in the source is not significantly deviated from the
equipartition condition in the {\gamma}-ray quiescent periods.Comment: 23 pages, accepted by JKA
Indentations on Air Plasma Sprayed Thermal Barrier Coatings Prepared by Different Starting Granules
The effect of starting granules on the indentation properties of air plasma sprayed thermal barrier coatings (TBCs) is investigated in this paper. Various kinds of spray-dried granules are prepared from different processing conditions, especially varying solvent and dispersant, showing a deformed hollow-typed and a filled spherical-typed granule. The similar coating thicknesses are prepared by adjusting process parameters during air plasma spray. All XRD peaks in phase analysis are tetragonal and cubic phases without any monoclinic phase after the starting granules were heat-treated. A relatively porous microstructure of the coating layer could be obtained from the monodisperse granules, while a relatively dense microstructure resulted from the hollow-typed granules. The morphology and distribution of the granules crucially affect the microstructure of thermal barrier coatings and thus have influences on indentation properties such as indentation stress-strain curves, contact damage, and hardness. The implication concerning microstructure design of TBCs for gas turbine applications is considered
Formation of Nanometer-Thick Water Layer at High Humidity on Dynamic Crystalline Material Composed of Multi-Interactive Molecules
Crystalline powders self-assembled from interactive discrete molecules reversibly transformed from a porous structure to a 2D one with a nanometer-thick H2O layer by hydration/dehydration. Multi-point weak intermolecular interactions contributed to maintenance of each phase. This structure transformation induced a humidity-dependent ion conductivity change from insulator to 3.4 x 10(-3) S cm(-1).open1122sciescopu
- …