• Economic and Environmental Geology
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• v.21 no.3
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• pp.235-255
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• 1988

Talc deposit of pipe-like form occurrs in the lower part of the Hyangsanri Dolomite with a strike of N40 -50 E and a dip of 40 -50 NW which is one formation of the Ogcheon Super Croup. The pipi-like ore body plunge at about $40^{\circ}$ to the west and are parallel to the lineation developed in the area. Structural formulae of tales occurred in this deposit are close to the ieal composition $Mg_6Si_8O_{20}(OH)_4$ showing limited deviation from ideal one. Substitution of Al for Si in tetrahedral site is of little or nothing ranging 0-0.04 and octahedral occupancy is close to six ranging 5.88-5.98 atoms per unit cell. Predominant octahedaral cation is Mg and proportion of divalent cations is generally over 97percent. Calcite -dolomite thermometry is obtained by determining the mol % $MgCO_3$using of EPMA and XRD methods. The peak metamorphic temperature can be estimated at $470{\pm}30^{\circ}C$ in the area whereas carbonates occurred at near talc ore show lower temperature than $400^{\circ}C$ that the calcite solvus limit is not well established. It indicates that the talc deposit was formed at the lower temperature that the metamorphic temperature. Cosequently, the formation of talc by metamorphism is questionable and the alteratin zone developed around the talc ore is very limited. The occurrence of talc ore in the dolomite as well as mineralogy, calcite-dolomite geothermometry, chlorite geothermometry, field and microscopic evidence suggest that siliceous ascending hydrothermal solution along the fracture is responsible for the formation of talc. It was considered that the slight fracturing of dolomite was formed by deformation prior to the mineralization.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.535-544
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• 1998

Seasonal variation of the crab community in the eelgrass (Zostera marina) bed in Kwangyang Bay was studied based on the monthly collections through a year of 1994. The crab community in the eelgrass bed was composed of 21 species representing 12 families. The community was dominated by Charybdis Japonica, Telmessus acutidens, Hemigrapsus penicillatus, and Pugettia quadridens. Crabs collected in the study area were primarily small-sized species or early juveniles of large crab species. Most individuals had carapace width smaller than 25 mm except C. japonica and T. acutidens which had maximum carapace width over 85 mm. More than 5 species were collected every month except January and February (4 and 3 species, respectively). The peak abundance occurred in August and low abundances in autumn and winter. Species diversity indices showed that more diverse crabs were collected In spring and summer, and lesser ones in autumn and winter. The crabs in the study area can be grouped into three groups on the basis of their occurrence patterns: resident species, seasonal species, and temporary species. More abundant and more diverse crabs were collected during nighttime than daytime.

• Korean Journal of Bronchoesophagology
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• v.3 no.1
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• pp.109-114
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• 1997

Aspiration of foreign bodies into the airway is a common problem in spite of efforts to educate the public, and it can be sometimes fatal accidents. We clinically analyzed 101 cases of airway foreign bodies treated in the Department of Otolaryngology-Head and Neck Surgery, Korea University College of Medicine for the past 10 years comparing data with the previous articles. There was male predominance in the occurrence rate, being 72% in the male patients. The peak age was 1 to 3 years of age, and 84.2% was below age of 10. The most common symptom after foreign body aspiration was intractable cough, and obstructive emphysema was most commonly found on the initial chest X-rays. Foreign bodies were mainly located at the right main bronchus and left main bronchus was the next. Peanuts were the most common airway foreign bodies. Ventilating bronchoscopy was performed in the 99 cases and foreign bodies were successfully removed in most cases. There was 2 deaths(2%) resulted from hypoxia after bronchoscopy. The fact that complication rates increase with the duration of the foreign bodies in situ is clear. Therefore, prompt bronchoscopy in patients with suspected airway foreign bodies is essential for lower complication rates.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.401-414
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• 2017

Vegetation and landscape characteristics at the three highest summits of Republic of Korea, i.e. Seoraksan, Jirisan and Hallasan, are analyzed on the basis of species composition, physiognomy, vegetation distribution and structure of alpine plants, along with landform, geology, soil and habitat conditions. Dominant high mountain plants at three alpine and subalpine belts contain deciduous broadleaved shrub, Rhododendron mucronulatum var. ciliatum (31.6%), and evergreen coniferous small tree, Pinus pumila (26.3%) at Seoraksan, deciduous broadleaved tree, Betula ermanii (35.3%), evergreen coniferous tree, Picea jezoensis (23.5%) at Jirisan, and evergreen coniferous tree, Abies koreana (22.6%), deciduous broadleaved shrub, Rhododendron mucronulatum var. ciliatum, and Juniperus chinensis var. sargentii (19.4%) at Hallasan, respectively. Presence of diverse landscapes at the peak of Seoraksan, such as shrubland, grassland, dry land along with rocky areas, and open land may be the result of hostile local climate and geology. High proportion of grassland and wetland at the top of Jirisan may related to gneiss-based gentle topography and well developed soil deposits, which are beneficial to keep the moisture content high. Occurrence of grassland, shrubland, dry land, conifer vegetation, and rocky area at the summit of Hallasan may due to higher elevation, unique local climate, as well as volcanic origin geology and soil substrates. Presences of diverse boreal plant species with various physiognomy at alpine and subalpine belts, and wide range of landscapes, including rocky, grassland, shrubland, wetland, and conifer woodland, provide decisive clues to understand the natural history of Korea, and can be employed as an relevant environmental indicator of biodiversity and ecosystem stability.

• Journal of Trauma and Injury
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• v.31 no.3
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• pp.159-165
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• 2018

Purpose: Spinning-induced rhabdomyolysis (SIR) has been increasing in recent years and accounts for a large proportion of exercise-induced rhabdomyolysis (EIR). The purpose of this study was to compare the clinical features between SIR and non-spinning exercise-induced rhabdomyolysis (NSIR), and to analyze each of these clinical features. Methods: A retrospective chart review was conducted on patients treated due to EIR from January 2006 to March 2018. Patients were divided into the SIR and NSIR groups, and their clinical factors, outcome, and blood chemistries were compared and analyzed. Results: Sixty-two patients were enrolled in this study, with 23 (37.1%) and 39 (62.9%) patients categorized in the SIR and NSIR groups, respectively. The SIR group were mostly women (78.3% vs. 38.5%, p=0.002), more frequent EIR occurrence in the first exercise class (60.9% vs. 15.4%, p=0.001), and had most complaints of thigh pain (91.3% vs. 43.6%, p=0.001). The SIR group had a higher incidence rate despite its shorter exercise duration (90.5% vs. 62.9%, p=0.024), longer hospital stay (6.0 [4.5-7.0] vs. 5.0 [3.5-6.0] days, p=0.080), and higher rate of peak CPK (15,000 U/L or higher) (91.3% vs. 74.4%, p=0.182) compared to the NSIR group. Conclusions: SIR occurs at a higher rate during the first exercise class in women compared to NSIR, and the incidence rate is higher in SIR than in NSIR despite its shorter exercise duration (less than 60 minutes). It is necessary to recognize these risks during spinning exercises and to perform these exercises sequentially and systematically.

• Journal of Korean Society on Water Environment
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• v.36 no.6
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• pp.508-520
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• 2020

Dam reservoirs have been reported to contribute significantly to global carbon emissions, but unlike natural lakes, there is considerable uncertainty in calculating carbon emissions due to the complex of emission pathways. In particular, the method of calculating carbon dioxide (CO2) net atmospheric flux (NAF) based on a simple gas exchange theory from sporadic data has limitations in explaining the spatiotemporal variations in the CO2 flux in stratified reservoirs. This study was aimed to analyze the spatial and temporal CO2 distribution and mass balance in Daecheong Reservoir, located in the mid-latitude monsoon climate zone, by applying a two-dimensional hydrodynamic and water quality model (CE-QUAL-W2). Simulation results showed that the Daecheong Reservoir is a heterotrophic system in which CO2 is supersaturated as a whole and releases CO2 to the atmosphere. Spatially, CO2 emissions were greater in the lacustrine zone than in the riverine and transition zones. In terms of time, CO2 emissions changed dynamically according to the temporal stratification structure of the reservoir and temporal variations of algae biomass. CO2 emissions were greater at night than during the day and were seasonally greatest in winter. The CO2 NAF calculated by the CE-QUAL-W2 model and the gas exchange theory showed a similar range, but there was a difference in the point of occurrence of the peak value. The findings provide useful information to improve the quantification of CO2 emissions from reservoirs. In order to reduce the uncertainty in the estimation of reservoir carbon emissions, more precise monitoring in time and space is required.

• Journal of Environmental Science International
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• v.31 no.7
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• pp.543-553
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• 2022

The latest aerospace technology is important for the stable flight of a launch vehicle, but weather conditions on the day of launch are also one of the essential factors for successful launch campaign. If a launch vehicle is directly struck while preparing to take off from the launch pad on the day of launch or the electronic device are damaged by induced current during flight of the launch vehicle, this means launch failure and can lead to enormous national loss. Therefore, for a successful launch campaign, it is necessary to analyze the lightning detection characteristics of the Naro Space Center. In this study, the seasonal factors of the lightning that occurred over the Naro Space Center from 2003 to 2017, the influence of the polarity, and the correlation with the lightning intensity was confirmed. As a result, there was a high probability of intensive occurrence of multiple lightning strikes in summer, and a high proportion of positive (+) lightning strikes in winter. Lastly, in the distribution of the number of lightning strikes, an average of 2.0 to 2.5 negative (-) lightning strikes occurs in the coastal regions of the South and West Seas when one flash happens.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.1-13
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• 2022

A weighted linear combination of seismic fragility models previously developed for cut-and-cover railway tunnels was presented and the appropriateness of the combined model was evaluated. The seismic fragility function is expressed in the form of a cumulative probability function of the lognormal distribution based on the peak ground acceleration. The model uncertainty can be reduced by combining models independently developed. Equal weight is applied to four models. The new seismic fragility function was developed for each damage level by determining the median and standard deviation, which are model metrics. Comparing fragility curves developed for other bored tunnels, cut-and-cover tunnels for high-speed railway system have a similar level of fragility. We postulated that this is due to the high seismic design standard for high-speed railway tunnel.

• Wind and Structures
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• v.35 no.5
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• pp.309-322
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• 2022

Due to the complex terrain around high-speed railways, the windbreaks were established along different landforms, resulting in irregular windbreak transition regions between different subgrade infrastructures (flat ground, cutting, embankment, etc). In this paper, the effect of a windbreak transition on the wind flow around railways subjected to crosswinds was studied. Wind tunnel testing was conducted to study the wind speed change around a windbreak transition on flat ground with a uniform wind speed inflow, and the collected data were used to validate a numerical simulation based on a detached eddy simulation method. The validated numerical method was then used to investigate the effect of the windbreak transition from the flat ground to cutting (the "cutting" is a railway subgrade type formed by digging down from the original ground) for three different wind incidence angles of 90°, 75°, and 105°. The deterioration mechanism of the flow fields and the reasons behind the occurrence of the peak wind velocities were explained in detail. The results showed that for the windbreak transition on flat ground, the impact was small. For the transition from the flat ground to the cutting, the influence was relatively large. The significant increase in the wind speeds was due to the right-angle structure of the windbreak transition, which resulted in sudden changes of the wind velocity as well as the direction. In addition, the height mismatch in the transition region worsened the protective effect of a typical windbreak.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.347-362
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• 2022

Current vibration serviceability assessment criteria for wind-induced vibrations in tall buildings are based largely on human 'perception' thresholds which are shown not to be directly translatable to human 'acceptability' of vibrations. There is also a considerable debate about both the metrics and criteria for vibration acceptability, such as frequency of occurrence or peak vs mean vibration, and how these might vary with the nature of the vibration. Furthermore, the design criteria are necessarily simplified for ease of application so cannot account for a range of environmental, situational and human factors that may enhance or diminish the impact of vibrations on serviceability. The dual-site VSimulators facility was created specifically to provide an experimental platform to address gaps in understanding of human response to building vibration. This paper considers how VSimulators can be used to inform general design guidance and support design of specific buildings for habitability, in terms of vibration, which allow engineers and clients to make informed decisions with regard to sustainable design, in terms of energy and financial cost. This paper first provides a brief overview of current vibration serviceability assessment guidelines, and the current understanding and limitations of occupants' acceptability of wind-induced motion in tall buildings. It then describes how the dual-site VSimulators facility at the Universities of Bath and Exeter can be used to assess the effects of motion and environment on human comfort, wellbeing and productivity with examples of how the facility capabilities have been used to provide new, human experience based experimental research approaches.