46 research outputs found
Large Language Models for Semantic Monitoring of Corporate Disclosures: A Case Study on Korea's Top 50 KOSPI Companies
In the rapidly advancing domain of artificial intelligence, state-of-the-art
language models such as OpenAI's GPT-3.5-turbo and GPT-4 offer unprecedented
opportunities for automating complex tasks. This research paper delves into the
capabilities of these models for semantically analyzing corporate disclosures
in the Korean context, specifically for timely disclosure. The study focuses on
the top 50 publicly traded companies listed on the Korean KOSPI, based on
market capitalization, and scrutinizes their monthly disclosure summaries over
a period of 17 months. Each summary was assigned a sentiment rating on a scale
ranging from 1(very negative) to 5(very positive). To gauge the effectiveness
of the language models, their sentiment ratings were compared with those
generated by human experts. Our findings reveal a notable performance disparity
between GPT-3.5-turbo and GPT-4, with the latter demonstrating significant
accuracy in human evaluation tests. The Spearman correlation coefficient was
registered at 0.61, while the simple concordance rate was recorded at 0.82.
This research contributes valuable insights into the evaluative characteristics
of GPT models, thereby laying the groundwork for future innovations in the
field of automated semantic monitoring
Metal Surface Guided-Wireless Power Transfer System for Portable Applications With Multiple Receivers
Recently, research has been actively conducted to overcome various challenges observed in wireless power transfer (WPT) technology. However, as additional techniques are implemented, the complexity and cost of WPT systems increased. Therefore, there is a need for a new WPT method that can overcome the shortcomings of existing technology. This paper presents a metal surface guided-wireless power transfer (MSG-WPT) system for applications with multiple receivers (Rxs). First, a plate-wire propagation enhancer (PWPE) is shown to improve the power transfer efficiency (PTE). However, it is not suitable for portable receiving systems. Based on our analysis of the PWPE characteristics, applying an L-section lumped impedance-matching scheme instead of a PWPE can improve the portability of the Rx. A coil-based propagation enhancer (CPE), or a coil-based inductor (CI), can increase the power received if it replaces the lumped inductor in the L-section scheme. The MSG-WPT system does not experience the co-alignment issues that exist between a pair of transceivers (TRxs) in conventional WPT systems. It can also support multiple Rxs while ensuring that the PTE of each Rx is relatively unaffected. An electromagnetic simulation of the proposed MSG-WPT system is performed using a high-frequency structure simulator (HFSS), and measurements are conducted in a corresponding experimental environment. The system power efficiency is measured at -12 dB in the 4 MHz frequency band. The proposed MSG-WPT system with a CPE is adequately efficient and portable, while also allowing a more liberal arrangement of Rxs compared to other conventional WPT systems
Identification of preferential target sites for human DNA methyltransferases
DNA methyltransferases (DNMTs) play an important role in establishing and maintaining DNA methylation. Aberrant expression of DNMTs and their isoforms has been found in many types of cancer, and their contribution to aberrant DNA methylation has been proposed. Here, we generated HEK 293T cells stably transfected with each of 13 different DNMTs (DNMT1, two DNMT3A isoforms, nine DNMT3B isoforms and DNMT3L) and assessed the DNA methylation changes induced by each DNMT. We obtained DNA methylation profiles of DNA repetitive elements and 1505 CpG sites from 808 cancer-related genes. We found that DNMTs have specific and overlapping target sites and their DNA methylation target profiles are a reflection of the DNMT domains. By examining H3K4me3 and H3K27me3 modifications in the 808 gene promoter regions using promoter ChIP-on-chip analysis, we found that specific de novo DNA methylation target sites of DNMT3A1 are associated with H3K4me3 modification that are transcriptionally active, whereas the specific target sites of DNMT3B1 are associated with H3K27me3 modification that are transcriptionally inactive. Our data suggest that different DNMT domains are responsible for targeting DNA methylation to specific regions of the genome, and this targeting might be associated with histone modifications
Cross-National Differences in Victimization : Disentangling the Impact of Composition and Context
Varying rates of criminal victimization across countries are assumed to be the outcome of countrylevel structural constraints that determine the supply ofmotivated o¡enders, as well as the differential composition within countries of suitable targets and capable guardianship. However, previous empirical tests of these ‘compositional’ and ‘contextual’ explanations of cross-national di¡erences
have been performed upon macro-level crime data due to the unavailability of comparable individual-level data across countries. This limitation has had two important consequences for cross-national crime research. First, micro-/meso-level mechanisms underlying cross-national differences cannot be truly inferred from macro-level data. Secondly, the e¡ects of contextual measures (e.g. income inequality) on crime are uncontrolled for compositional heterogeneity. In this
paper, these limitations are overcome by analysing individual-level victimization data across 18 countries from the International CrimeVictims Survey. Results from multi-level analyses on theft and violent victimization indicate that the national level of income inequality is positively related to risk, independent of compositional (i.e. micro- and meso-level) di¡erences. Furthermore, crossnational variation in victimization rates is not only shaped by di¡erences in national context, but
also by varying composition. More speci¢cally, countries had higher crime rates the more they consisted of urban residents and regions with lowaverage social cohesion.
The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-filament Structure, Monoceros R2
We present and analyze observations of polarized dust emission at 850 μm toward the central 1
7 1 pc hub-filament structure of Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the B-fields in Star-forming Region Observations survey. The orientations of the magnetic field follow the spiral structure of Mon R2, which are well described by an axisymmetric magnetic field model. We estimate the turbulent component of the magnetic field using the angle difference between our observations and the best-fit model of the underlying large-scale mean magnetic field. This estimate is used to calculate the magnetic field strength using the Davis–Chandrasekhar–Fermi method, for which we also obtain the distribution of volume density and velocity dispersion using a column density map derived from Herschel data and the C18O (J = 3 - 2) data taken with HARP on the JCMT, respectively. We make maps of magnetic field strengths and mass-to-flux ratios, finding that magnetic field strengths vary from 0.02 to 3.64 mG with a mean value of 1.0 \ub1 0.06 mG, and the mean critical mass-to-flux ratio is 0.47 \ub1 0.02. Additionally, the mean Alfv\ue9n Mach number is 0.35 \ub1 0.01. This suggests that, in Mon R2, the magnetic fields provide resistance against large-scale gravitational collapse, and the magnetic pressure exceeds the turbulent pressure. We also investigate the properties of each filament in Mon R2. Most of the filaments are aligned along the magnetic field direction and are magnetically subcritical
The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43
We present observations of polarized dust emission at 850 μm from the L43 molecular cloud, which sits in the Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope as a part of the BISTRO large program. L43 is a dense (NH 10
22 2 ~ –1023 cm−2) complex molecular cloud with a submillimeter-bright starless core and two protostellar sources. There appears to be an evolutionary gradient along the isolated filament that L43 is embedded within, with the most evolved source closest to the Sco OB2 association. One of the protostars drives a CO outflow that has created a cavity to the southeast. We see a magnetic field that appears to be aligned with the cavity walls of the outflow, suggesting interaction with the outflow. We also find a magnetic field strength of up to ∼160 ± 30 μG in the main starless core and up to ∼90 ± 40 μG in the more diffuse, extended region. These field strengths give magnetically super- and subcritical values, respectively, and both are found to be roughly trans-Alfvénic. We also present a new method of data reduction for these denser but fainter objects like starless cores
Filamentary Network and Magnetic Field Structures Revealed with BISTRO in the High-mass Star-forming Region NGC 2264: Global Properties and Local Magnetogravitational Configurations
We report 850 μm continuum polarization observations toward the filamentary high-mass star-forming region NGC 2264, taken as part of the B-fields In STar forming Regions Observations large program on the James Clerk Maxwell Telescope. These data reveal a well-structured nonuniform magnetic field in the NGC 2264C and 2264D regions with a prevailing orientation around 30° from north to east. Field strength estimates and a virial analysis of the major clumps indicate that NGC 2264C is globally dominated by gravity, while in 2264D, magnetic, gravitational, and kinetic energies are roughly balanced. We present an analysis scheme that utilizes the locally resolved magnetic field structures, together with the locally measured gravitational vector field and the extracted filamentary network. From this, we infer statistical trends showing that this network consists of two main groups of filaments oriented approximately perpendicular to one another. Additionally, gravity shows one dominating converging direction that is roughly perpendicular to one of the filament orientations, which is suggestive of mass accretion along this direction. Beyond these statistical trends, we identify two types of filaments. The type I filament is perpendicular to the magnetic field with local gravity transitioning from parallel to perpendicular to the magnetic field from the outside to the filament ridge. The type II filament is parallel to the magnetic field and local gravity. We interpret these two types of filaments as originating from the competition between radial collapsing, driven by filament self-gravity, and longitudinal collapsing, driven by the region's global gravity
The TOP-SCOPE Survey of Planck Galactic Cold Clumps : Survey Overview and Results of an Exemplar Source, PGCC G26.53+0.17
The low dust temperatures (<14 K) of Planck Galactic cold clumps (PGCCs) make them ideal targets to probe the initial conditions and very early phase of star formation. "TOP-SCOPE" is a joint survey program targeting similar to 2000 PGCCs in J = 1-0 transitions of CO isotopologues and similar to 1000 PGCCs in 850 mu m continuum emission. The objective of the "TOP-SCOPE" survey and the joint surveys (SMT 10 m, KVN 21 m, and NRO 45 m) is to statistically study the initial conditions occurring during star formation and the evolution of molecular clouds, across a wide range of environments. The observations, data analysis, and example science cases for these surveys are introduced with an exemplar source, PGCC G26.53+0.17 (G26), which is a filamentary infrared dark cloud (IRDC). The total mass, length, and mean line mass (M/L) of the G26 filament are similar to 6200 M-circle dot, similar to 12 pc, and similar to 500 M-circle dot pc(-1), respectively. Ten massive clumps, including eight starless ones, are found along the filament. The most massive clump as a whole may still be in global collapse, while its denser part seems to be undergoing expansion owing to outflow feedback. The fragmentation in the G26 filament from cloud scale to clump scale is in agreement with gravitational fragmentation of an isothermal, nonmagnetized, and turbulent supported cylinder. A bimodal behavior in dust emissivity spectral index (beta) distribution is found in G26, suggesting grain growth along the filament. The G26 filament may be formed owing to large-scale compression flows evidenced by the temperature and velocity gradients across its natal cloud.Peer reviewe
Filamentary Network and Magnetic Field Structures Revealed with BISTRO in the High-Mass Star-Forming Region NGC2264 : Global Properties and Local Magnetogravitational Configurations
We report 850 m continuum polarization observations toward the
filamentary high-mass star-forming region NGC 2264, taken as part of the
B-fields In STar forming Regions Observations (BISTRO) large program on the
James Clerk Maxwell Telescope (JCMT). These data reveal a well-structured
non-uniform magnetic field in the NGC 2264C and 2264D regions with a prevailing
orientation around 30 deg from north to east. Field strengths estimates and a
virial analysis for the major clumps indicate that NGC 2264C is globally
dominated by gravity while in 2264D magnetic, gravitational, and kinetic
energies are roughly balanced. We present an analysis scheme that utilizes the
locally resolved magnetic field structures, together with the locally measured
gravitational vector field and the extracted filamentary network. From this, we
infer statistical trends showing that this network consists of two main groups
of filaments oriented approximately perpendicular to one another. Additionally,
gravity shows one dominating converging direction that is roughly perpendicular
to one of the filament orientations, which is suggestive of mass accretion
along this direction. Beyond these statistical trends, we identify two types of
filaments. The type-I filament is perpendicular to the magnetic field with
local gravity transitioning from parallel to perpendicular to the magnetic
field from the outside to the filament ridge. The type-II filament is parallel
to the magnetic field and local gravity. We interpret these two types of
filaments as originating from the competition between radial collapsing, driven
by filament self-gravity, and the longitudinal collapsing, driven by the
region's global gravity.Comment: Accepted for publication in the Astrophysical Journal. 43 pages, 32
figures, and 4 tables (including Appendix