• Economic and Environmental Geology
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• v.57 no.1
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• pp.1-15
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• 2024

The Melanesian region in the western Pacific is dominated by complex plate tectonics, with the largest oceanic plateau, the OntongJava plateau, and a hotspot, the Caroline Islands. To better understand the complex geodynamics of the region, we estimate P- and S-velocity models and 𝛿 (V_P/V_S) model by using relative teleseismic travel times measured at seismometers on land and the seafloor. Our results show high-velocity anomalies in the subduction zones of the Melanesian region to a depth of about 400 km, which is thought to be subducting Solomon Sea, Bismarck, and Australian plates along plate boundaries. Along subduction zones, positive 𝛿 (V_P/V_S) anomalies are found, which may be caused by partial melting due to dehydration. A broad high-velocity anomaly is observed at 600 km depth below the Ontong-Java plateau, with a negative 𝛿 (V_P/V_S) anomaly. This is thought to be a viscous and dry remnant of the Pacific plate that subducted at 45-25 Ma, with a low volume of fluids due to dehydration for a long period in the mantle transition zone. Beneath the Caroline Islands, a strong low-velocity anomaly is obseved to a depth of 800 km and appears to be connected to the underside of the remnant Pacific plate in the mantle transition zone. This suggests that the mantle plume originating in the lower mantle has been redirected due to the interaction with the remnant Pacific plate and has reached its current location. The mantle plume also has a positive 𝛿 (V_P/V_S) anomaly, which is thought to be due to the influence of embedded fluids or partial melting. A high-velocity anomaly, interpreted as an effect of the thick lithosphere beneath the Ontong-Java plateau, is observed down to 300 km depth with a negative 𝛿 (V_P/V_S) anomaly, which likely indicate that little fluid remains in the melt residue accumulated in the lithosphere.

• Journal of the Korean Society of Radiology
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• v.8 no.6
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• pp.293-299
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• 2014

Compton suppression device is a device by using the Compton scattering reaction and suppress the Compton continuum portion of the spectrum, so can be made more clear analysis of gamma ray peak in the Compton continuum region. Measurements above background occurs or, radioactivity counts of radioactivity concentration value of $^{40}K$ nuclides $^{137}Cs$ and natural radioactivity artificial radioactivity detected from the surface soil sample, unwanted non-target analysis and interference peak who dotted line you know the calibration of the measurement energy is allowed to apply the (Compton suppression) non-suppressed spectrum inhibition spectrum and (Compton Unsuppression) the background to the measured value of the activity concentration value of the standard-ray source is detected relative to the peak of By measuring according to the different distances cause $^{137}Cs$, and comparative analysis of the Monte Carlo simulation, in order to obtain a detection capability for efficient, looking at the Compton inhibitor, as the CSF value increases with increase in the distance, more It was found that the background due to Compton continuum of the measured spectrum suppression mode Compton unrestrained mode can know that the Compton suppression many were made, using a $^{137}Cs$ is reduced.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2895-2901
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• 2011

SeoulMetro(line number 1 to 4) for the first half of the year. Therefore air quality in the subway is very important. It is passengers, such as sneezing and respiratory vital activities, Suspended due to skin keratin microbial action, and Microbial contaminants such as viruses. Hypersensitivity disorders, an atopic dermatitis, infectious diseases, allergic diseases, and can cause respiratory diseases. Ministry of Environment and National Institute of Environmental Research is managed so the life bacteria. It is emerging as the occupational health problems. Introduction of an appropriate ventilation system for cooling and dehumidification is needed. In line number 2, commuting and normal trains are measured in-room floating microbes. Suspended bacteria and fungi suspended in 2011 for 85 ~ 385$cfu/m^3$, 67 ~ 98$cfu/m^3$ is lower than baseline. Suspended to prevent microbial contamination and air conditioning equipment performance is a substantial improvement. Suspended micro-organisms and the impact on passenger room ventilation is increased. Electric car how to improve air quality substantially investigated.

• Journal of Gifted/Talented Education
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• v.23 no.2
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• pp.215-236
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• 2013

In this study, we seek to improve the quality of education at institutes for science gifted education in universities by analysing the curriculums. Annual reports were analyzed, directors, professors, and students participated in the survey, directors were interviewed. The number of students was three times more than enrichment step than mentorship step. In content items, four items among nine received scores was 4 on the 5 point Likert scale. In the teaching and learning process items, five items among ten received scores 4. Students' choice and experience received scores below 4. In the product and the learning environment items, all items lower than 4. The professors did not supply guidance according to the results of the assessment. The professors developed and revised the curriculum considering the students' interests. The directors, professors, and students wanted to increase the free inquiry time. Based on the findings, we suggested that free inquiry time, a variety of experience, product, and environment considering individual students' abilities and interests should be increased.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.5
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• pp.581-594
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• 2012

The goal of this study is to investigate the effects of the chemical lateral boundary conditions (CLBCs) on Community Multi-scale Air Quality (CMAQ) simulations of tropospheric ozone for East Asia. We developed linking tool to produce CLBCs of CMAQ from Goddard Earth Observing System-Chemistry (GEOS-Chem) as a global chemistry model. We examined two CLBCs: the fixed CLBC in CMAQ (CLBC-CMAQ) and the CLBC from GEOS-Chem (CLBC-GEOS). The ozone fields by CMAQ simulation with these two CLBCs were compared to Tropospheric Emission Spectrometer (TES) satellite data, ozonesonde and surface measurements for May and August in 2008. The results with CLBC-GOES showed a better tropospheric ozone prediction than that with CLBC-CMAQ. The CLBC-GEOS simulation led to the increase in tropospheric ozone concentrations throughout the model domain, due to be influenced high ozone concentrations of upper troposphere and near inflow western and northern boundaries. Statistical evaluations also showed that the CLBC-GEOS case had better results of both the index of Agreement (IOA) and mean normalized bias. In the case of IOA, the CLBC-GEOS simulation was improved about 0.3 compared to CLBC-CMAQ due to the better predictions for high ozone concentrations in upper troposphere.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.682-693
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• 2012

This study was intented to understand the insects diversity and forest in DMZ, and provide data and information required to preserve living creatures and geological management, and basic information for the management and preservation policies. This study has surveyed insects diversity by habitat types in Middle Inland of DMZ, Korea from 15 to 19 September, 2009. Totally there were 128 species belonging to 53 families of 10 orders, among them, 7 endermic species, 3 management of exotic species and 25 designated species were showed. The highest was 26 species of Hemiptera(20.31%) and then next turn are 22 species of Coleoptera(17.19%) and 20 species of Hymenoptera(15.63%) respectively. Dominant species are Ceracris nigricornislaeta (Bolivar)(0.152) in S1, Menida violacea Motschulsky(0.218) in S2, Stomorhina obsoleta (Wiedemann)(0.171) in S3, Ducetia japonica (Thunberg)(0.212) in S4, Oedaleus infernalis Saussure(0.178) in S5, Sepedon aenescens Wiedemann(0.268) in S6, Adelphocoris triannulatus (Stal)(0.257) in S7 and Ricania taeniata Stal(0.150) in S8 site. The diversity(H') and richness(RI) of insects at survey area as S2(H'=3.461, RI=9.64), S3(H'=3.457, RI=9.18) and S1(H'=3.447, RI=8.88) were higher than in the others and the lowest in S8(H'=2.790, RI=5.341). But the highest species evenness index(EI) occurred in S8(0.985).

• Korean Journal of Environment and Ecology
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• v.34 no.3
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• pp.235-248
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• 2020

The purpose of this study was to quantitatively analyze and investigate changes in the structural characteristics of the warm-temperate evergreen broad-leaved forest community in Mt. Cheomchalsan on Jindo Island. The Mt. Cheomchalsan has high conservation value because the representative warm temperate species such as Quercus acuta and Castanopsis sieboldii are distributed there. The community classification with TWINSPAN and DCA identified 4 communities: C. sieboldii community (I), C. sieboldii-Q. Salicina community (II), Q. acuta-C.sieboldii community (III), and deciduous broad-leaved trees-evergreen broad-leaved trees community (IV). According to the results of the mean importance percentage (MIP) analysis, C. sieboldii, Q. salicina, and Q. acuta were dominant species in the canopy layer, Camellia japonica, Ligustrum japonicum, and Cinnamomum yabunikkei were dominant in the understory layer, and Trachelospermum asiaticum, C. japonica, and C. sieboldii were dominant in the shrub layer. The comparison of the results of the diameter of breast height (DBH) analysis with the past data showed that the ratio of large-sized trees in the C. sieboldii and Q. acuta, which dominated the canopy layer, increased. However, there was no difference in the distribution of C. japonica and L. japonicum in the understory layer. In the future, it is necessary to generate a precision inhabiting vegetation map around the Natural Reserve to understand the actual habitation of evergreen broad-leaved trees and rezone the protective districts of evergreen broad-leaved trees forest with the watershed concept to preserve the evergreen broad-leaved forests of Mt. Cheomchalsan in Jindo.

• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.393-399
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• 2016

This study was conducted to elucidate the photosynthetic response to the environment and establish optimum cultivation conditions for the Korean endemic plant, Aster koraiensis. Photosynthetic characteristics according to growth stage, light, CO₂, and soil water potential were investigated. During the first year of transplanting, photosynthetic rates were drastically increased until June, after which they slowly declined, During the second year, photosynthetic rates declined throughout the entire growth period. The highest level of light compensation point was shown the early growth stage. Photosynthetic rates affected by intercellular CO₂ concentration were maintained or decreased over the CO₂ saturation point. The lowest CO₂ compensation point was 16.1 μmol·mol⁻¹ during March. The morphological changes of leaves were observed due to shading with chlorophyll contents increasing. Photosynthetic rates were higher at 0% and 50% shading treatments than at 75%. There were rarely any morphological changes of leaves due to soil moisture, however, changes to leaf compactness were observed. Photosynthetic rate, apparent quantum yield, and respiration rate increased, whereas water use efficiency decreased over −25 kPa of soil moisture.

• The Journal of the Acoustical Society of Korea
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• v.39 no.1
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• pp.47-56
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• 2020

The sound source localization technique has various application fields in the era of internet-of-things, for which the probe size becomes critical. The localization methods using the acoustic intensity vector has an advantage of downsizing the layout of the array owing to a small finite-difference error for the short distance between adjacent microphones. In this paper, the acoustic intensity vector and the Time Difference of Arrival (TDoA) method are compared in the viewpoint of the localization error in the far-field. The comparison is made according to the change of spacing between adjacent microphones of the three-dimensional microphone array arranged in a tetrahedral shape. An additional test is conducted in the reverberant field by varying the reverberation time to verify the effectiveness of the methods applied to the actual environments. For estimating the TDoA, the Generalized Cross Correlation-Phase transform (GCC-PHAT) algorithm is adopted in the computation. It is found that the mean localization error of the acoustic intensimetry is 2.9° and that of the GCC-PHAT is 7.3° for T₆₀ = 0.4 s, while the error increases as 9.9°, 13.0° for T₆₀ = 1.0 s, respectively. The data supports that a compact array employing the acoustic intensimetry can localize of the sound source in the actual environment with the moderate reflection conditions.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.398-412
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• 2017

The aim of this study was to collect the basic data for effective creation and management of hilly pasture. The investigation of flora and vegetation was conducted at 59 $relev\acute{e}s$ in hilly pasture of Daegwallyeong from 2014 to 2016. The vascular plants of the hilly pasture were 121 listed taxa which contain 38 families, 90 genera, 104 species, 13 varieties, and 12 subspecies. The biological type of the hilly pasture was determined as the $Th-D_4-R_5-e$ type. Twelve taxa were of naturalized plants composed of 5 families, 9 genera, 12 species. The urbanization index and the naturalized index were 3.7% and 9.9%, respectively. The vegetation types in the hilly pasture were classified into the following 3 communities: the Spiraea miyabei-Spiraea salicifolia community, the Persicaria thunbergii community, and the Agrostis alba-Phleum pratense community. The Agrostis alba-Phleum pratense community was classified into the following 5 subcommunities: the Poa pratensis subcommunity, the Artemisia princeps subcommunity, the Festuca ovina subcommunity, the Rumex acetosella subcommunity, and the typical subcommunity. Two factors (slope and EC) had the strongest impact on plant community distribution. Especially, the steep sloping sites (over $40^{\circ}$) did not play a crucial role in maintaining adequate pasture because of the invasion and establishment of shrubs.