• Archives of Craniofacial Surgery
• /
• v.22 no.5
• /
• pp.254-259
• /
• 2021

Background: Prophylactic antibiotics are commonly used in craniofacial surgeries. Despite the low risk of surgical site infection after nasal surgery, a lack of consensus regarding the use of antibiotic prophylaxis in the closed reduction of nasal bone fractures has led to inappropriate prescribing patterns. Through this study, we aimed to investigate the status of prophylactic antibiotic use in closed reductions of nasal bone fractures in Korea. Methods: This retrospective cohort study was conducted using data from the National Health Insurance Service-National Sample Cohort of Korea from 2005 to 2015. We analyzed the medical records of patients who underwent closed reduction of nasal bone fractures. The sex, age, region of residence, comorbidities, and socioeconomic variables of the patients were collected from the database. Factors that affect the prescription of perioperative antibiotics were evaluated using multivariate logistic regression analysis. Results: A total of 3,678 patients (mean±standard deviation of age, 28.7±14.9 years; 2,850 men [77.5%]; 828 women [22.5%]) were included in this study. The rate of antibiotic prescription during the perioperative period was 51.4%. Approximately 68.8% of prescriptions were written for patients who had received general anesthesia. The odds of perioperative prophylactic antibiotic use were significantly higher in patients who received general anesthesia than who received local anesthesia (odds ratio, 1.59). No difference was found in terms of patient age and physician specialty. Second-generation cephalosporins were the most commonly prescribed antibiotic (45.3%), followed by third- and first-generation cephalosporins (20.3% and 18.8%, respectively). In contrast, lincomycin derivatives and aminoglycosides were not prescribed. Conclusion: The findings of this study showed that there was a wide variety of perioperative antibiotic prescription patterns used in nasal bone surgeries. Evidence-based guidance regarding the prescribing of antimicrobial agents for the closed reduction of nasal bone fractures should be considered in future research.

• The Plant Pathology Journal
• /
• v.34 no.6
• /
• pp.532-543
• /
• 2018

Complete genome sequences of 22 isolates of Cucurbit aphid-borne yellows virus (CABYV), collected from melon plants showing yellowing symptom in Korea during the years 2013-2014, were determined and compared with previously reported CABYV genome sequences. The complete genomes were found to be 5,680-5,684 nucleotides in length and to encode six open reading frames (ORFs) that are separated into two regions by a non-coding internal region (IR) of 199 nucleotides. Their genomic organization is typical of the genus Polerovirus. Based on phylogenetic analyses of complete nucleotide (nt) sequences, CABYV isolates were divided into four groups: Asian, Mediterranean, Taiwanese, and R groups. The Korean CABYV isolates clustered with the Asian group with > 94% nt sequence identity. In contrast, the Korean CABYV isolates shared 87-89% sequence identities with the Mediterranean group, 88% with the Taiwanese group, 81-84% with the CABYV-R group, and 72% with another polerovirus, M.. Recombination analyses identified 24 recombination events (12 different recombination types) in the analyzed CABYV population. In the Korean CABYV isolates, four recombination types were detected from eight isolates. Two recombination types were detected in the IR and P3-P5 regions, respectively, which have been reported as hotspots for recombination of CABYV. This result suggests that recombination is an important evolutionary force in the genetic diversification of CABYV populations.

• Journal of Positioning, Navigation, and Timing
• /
• v.8 no.2
• /
• pp.79-85
• /
• 2019

The mission tasks of polar exploration utilizing unmanned systems such as glacier monitoring, ecosystem research, and inland exploration have been expanded. To facilitate unmanned exploration mission tasks, precise and robust navigation systems are required. However, limitations on the utilization of satellite navigation system are present due to satellite orbital characteristics at the polar region located in a high latitude. The orbital inclination of global positioning system (GPS), which was developed to be utilized in mid-latitude sites, was designed at $55^{\circ}$. This means that as the user is located in higher latitudes, the satellite visibility and vertical precision become worse. In addition, the use of satellite-based wide-area augmentation system (SBAS) is also limited in higher latitude regions than the maximum latitude of signal reception by stationary satellites, which is $70^{\circ}$. This study proposes a local-area augmentation system that additionally utilizes Global Navigation Satellite System (GLONASS) considering satellite navigation system environment in Polar Regions. The orbital inclination of GLONASS is $64.8^{\circ}$, which is suitable in order to ensure satellite visibility in high-latitude regions. In contrast, GLONASS has different system operation elements such as configuration elements of navigation message and update cycle and has a statistically different signal error level around 4 m, which is larger than that of GPS. Thus, such system characteristics must be taken into consideration to ensure data integrity and monitor GLONASS signal fault. This study took GLONASS system characteristics and performance into consideration to improve previously developed fault detection algorithm in the local-area augmentation system based on GPS. In addition, real GNSS observation data were acquired from the receivers installed at the Antarctic King Sejong Station to analyze positioning accuracy and calculate test statistics of the fault monitors. Finally, this study analyzed the satellite visibility of GPS/GLONASS-based local-area augmentation system in Polar Regions and conducted performance evaluations through simulations.

• Journal of Broadcast Engineering
• /
• v.24 no.1
• /
• pp.67-76
• /
• 2019

In this paper, we propose an efficient object classification method based on semantic segmentation for multi-labeled image data. In addition to various pixel unit information and processing techniques such as color information, contour, contrast, and saturation included in image data, a detailed region in which each object is located is extracted as a meaningful unit and the experiment is conducted to reflect the result in the inference. We use a neural network that has been proven to perform well in image classification to understand which object is located where image data containing various class objects are located. Based on these researches, we aim to provide artificial intelligence services that can classify real-time detailed areas of complex images containing various objects in the future.

• Journal of The Geomorphological Association of Korea
• /
• v.25 no.1
• /
• pp.31-45
• /
• 2018

This study investigated the characteristics of sedimentary environment changes across a tidal flat in Gagyeongju of Anmyeondo Island. We performed a spatio-temporal analysis on the grain sizes composition of sediments and micro-landform changes during the winter from 2013 to 2016. The results showed that erosion was a dominant processthroughout the study flat, reducing the surface elevation even by 1 m around the upper sand flat. As a consequence, headlands have formed in the entire region of Gagyeongju village. In addition, erosion quickly progressed along the low-lying subtidal zone and tide way and, in contrast, sedimentation progressed in the mid-elevation tidal flat. We posit that a jetty, which had been constructed as a pier facility on the eastern part of the study area, interfered with the flow of tidal current, thereby enhancing these erosional processes. This is because such interference can block the supply of fine-textured sediments from the nearby Cheonsu Bay and therefore reduce surface elevation. According to the surface sediment analysis, the sediments were categorized into 7 sedimentary facies, and generally displayed a high ratio of silt and clay. The result of time-series analysis (2012-2013) showed that the sediments on the tidal flat became fine-grained, and that sorting became worse. However, the sediments on the subtidal zone, embayment and along inside of the jetty tended to be coarse-grained. In conclusion, the tidal flat microlandform change in the study area was caused by a disruption in the seawater circulation due to the jittery construction within the tidal flat, which had a direct effect on erosional and sedimentary environment processes.

• Korean Journal of Metals and Materials
• /
• v.47 no.12
• /
• pp.811-818
• /
• 2009

In order to meet increasingly complex and rigorous technical specifications, extensive effort has been devoted to fabricate clad materials with multi-layered metal plates. In this study, novel stainless steel/aluminum/copper (STS/Al/Cu) three-ply clad materials were fabricated by a hot rolling process for cookware applications. The effect of the testing temperature on the mechanical properties of the clad materials and on each component metal was investigated during the tensile tests. The interface properties of the clad materials were also examined by optical microscopy (OM) and an electron probe micro-analyzer (EPMA). The best mechanical and interfacial properties for a warm working process were found in a sample annealed at a temperature of $300^{\circ}C$. For the sample annealed at $400^{\circ}C$, the results of the tensile test indicated that interface delamination occurred only in the region of the Al/Cu interfaces. This was due to the formation of the thick and brittle intermetallic compound of $Al_2Cu$ in the Al/Cu interface. In contrast, no interface delamination was observed in the STS/Al interface, most likely due to its strong bond strength.

• Journal of Veterinary Clinics
• /
• v.38 no.3
• /
• pp.159-162
• /
• 2021

A 5-year-old, intact male, poodle dog with right external auditory canal obstruction and subaural mass was presented. Physical examination revealed that right external auditory canal opening was absent and right head tilt was identified. Aspiration in right subaural mass revealed a small amount of dark brown exudate. Streptococcus canis and Staphylococcus spp. were identified on the microbial culture. Radiography of the skull was revealed absence of air-filled ear canal at the right external ear canal (EEC) level. Computed tomography (CT) revealed well capsulated, hypoattenuated mass in the right EEC region. On the contrast enhanced CT images, rim enhancement around the mass and ear canal obstruction were identified. Fluid attenuated material filled with right bulla. Mild thickening of the right tympanic bulla wall with mild lytic lesion of the ventral wall were found. Based on the images findings, the case was tentatively diagnosed as right external auditory canal atresia with otitis media. Total ear canal ablation and lateral bulla osteotomy was performed. The entire ear canal was removed, numerous hair in the canal and the thickening wall were founded. Right ear canal was sent for histopathological evaluation and found to otitis externa. The patient was followed up for two weeks and there were no complications. This report described the CT diagnosis of right EEC atresia with otitis media rarely reported in small breed dogs.

• Atmosphere
• /
• v.30 no.4
• /
• pp.361-376
• /
• 2020

This study evaluates multiple Regional Climate Models (RCMs) in simulating temperature and precipitation over the Far East Asia (FEA) and estimates the portions of the total uncertainty originating in the RCMs and the driving Global Climate Models (GCMs) using nine present-day (1981~2000) climate data obtained from combinations of three GCMs and three RCMs in the CORDEX-EA phase2. Downscaling using the RCMs generally improves the present temperature and precipitation simulated in the GCMs. The mean temperature climate in the RCM simulations is similar to that in the GCMs; however, RCMs yield notably better spatial variability than the GCMs. In particular, the RCMs generally yield positive added values to the variability of the summer temperature and the winter precipitation. Evaluating the uncertainties by the GCMs (VARGCM) and the RCMs (VARRCM) on the basis of two-way ANOVA shows that VARRCM is greater than VARGCM in contrast to previous studies which showed VARGCM is larger. In particular, in the winter temperature, the ocean has a very large VARRCM of up to 30%. Precipitation shows that VARRCM is greater than VARGCM in all seasons, but the difference is insignificant. In the following study, we will analyze how the uncertainty of the climate model in the present-day period affects future climate change prospects.

• ALGAE
• /
• v.37 no.2
• /
• pp.123-133
• /
• 2022

Genetic diversity and distribution patterns of marine macroalgae are increasingly being documented in Southeast Asia. These studies show that there can be significant levels of genetic diversity and isolation between populations on either side of the Thai-Malay Peninsula. Bostrychia tenellla is a common filamentous red seaweed in the region and the entity is represented by at least two cryptic species. Despite being highly diverse and widespread, genetic variation and population structure of this species complex remains understudied, especially around the Thai-Malay Peninsula. We analyzed genetic diversity and inferred the phylogeographic pattern of specimens identified as B. tenella using the plastid RuBisCo spacer from samples from the Andaman Sea and the Gulf of Thailand. Our genetic analysis confirmed the occurrence of the two cryptic B. tenella species (B and C) along both coasts. Cryptic species B was more common in the area and displayed higher genetic diversity than species C. Historical demographic analyses indicated a stable population for species B, but more recent population expansion for species C. Our analyses also revealed that both cryptic species from the Andaman Sea possessed higher genetic diversity than those of the Gulf of Thailand. We also detected moderate to high levels of gene flow and weak phylogeographic structure of cryptic species B between the two coasts. In contrast, phylogeographic analysis showed genetic differences between populations of both cryptic species within the Andaman Sea. Overall, these results suggest that cryptic B. tenella species around Thai-Malay Peninsula may have undergone different demography histories, and their patterns of genetic diversity and phylogeography were likely caused by geological history and regional sea surface current circulation in the area.

• The Journal of Korean Society of Virology
• /
• v.30 no.3
• /
• pp.203-210
• /
• 2000

Hantaviruses are etiologic agents of hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS) in the world. Various hantaviruses were isolated from HFRS patients and several different rodent species in the world. Four hantavirus isolates from Indonesia and three isolates from Thailand among 89 Bandicotas captured in Yogyakarta, east region of Sumatra island, Indonesia and at Chiang Mai in Thailand during 1996 were made through several passages in Vero E6 cells. Viral genome M segment from two Indonesian isolates and three Thailand isolates were amplified using hantavirus generic primers of the M segment and cloned into pCRII vector. The genetic differences were analyzed by comparison of partial sequence of the M segment and antigenic differences were made by IFA. Nucleotide sequence homology of two isolates BC 8, BC 34 from Indonesia and two isolates thai 1322, thai 1330 to Seoul virus was 99% and 96%, respectively, but Thai 1164 was 80%Thai 1164 strain has shown 95% homology to Thai 749 virus. In conclusion it is indicated that two different serotype hantaviruses, Seoul and Thailand, are cocirculating among Bandicota in Thailand, in contrast Seoul serotype virus is circulating in Indonesia.