• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.169-181
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• 2014

Korea government has consistently investigated the development of economic mineral deposits in the Tofua volcanic arc, Tonga since 2008 for the secure of sea floor mineral resources. We studied the composition and distribution of minerals formed by hydrothermal activity around TA 25 seamounts of the Tofua volcanic arc, Lau Basin, Tonga, using X-ray diffraction analysis, scanning electron microscopy, X-ray fluorescence spectrometry, and inductively coupled plasma atomic emission spectrometry. We used 7 core samples and 9 surface sediment samples. Barite, sphalerite, and clinoclase are present in the most volcanic vent area. Gypsum, smectite, and kaolin mineral are distributed in vent A area, chalcopyrite, pyrite, smectite, and kaolin mineral are in vent B and C area, and gypsum, chalcopyrite, pyrite, and goethite are in vent D area. From the study of clay fraction, smectite and few kaolinite are detected in the most studied area except inner part of caldera, which suggest that argillic alteration are dominant in the volcanic vent areas. Various sulfide or arsenide minerals were found in the hydrothermal vent B, C, and D. The mineralogy and geochemistry suggest higher hydrothermal activities in volcanic vent B, C, and D compared to vent A and inner caldera area. Therefore higher probabilities of massive sulfide deposits may occur in hydrothermal vent B, C, and D.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.311-317
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• 2007

The purpose of this study is to evaluate the nutrient intake and selected blood parameters of adults with metabolic syndrome (MS) and to provide data in forming a dietary guideline for the prevention of chronic diseases. Subjects were recruited and divided into two groups according to the NCEP-ATP III criteria and WHO Asia-Pacific Area criteria for obesity. MS group was defined as subjects who have three or more risk factors and control group was defined as those with two or less of the risk factors. The average age, height, weight, body mass index (BMI) were 58.8 years, 158.0 cm, 66.3 kg, $26.5\;kg/m^{2}$, respectively, in the MS group; and 58.4 years, 158.9 cm, 59.6 kg, $23.5\;kg/m^{2}$, respectively, in the control group. The weight and BMI in the MS group were significantly higher than those in the control (p<0.001). There was no significant difference in the food and nutrient intake between the MS and control group. Male subjects in the MS group showed significantly higher intake of mushrooms than those in the control (p<0.05). Egg consumption in the MS group was significantly lower than those in the control (p<0.01). Consumption of vegetables and fiber was significantly lower for female subjects in the MS group than those in the control (p<0.05). Serum GPT, AI and WBC count in the MS group (27.8 IU/L, 3.7, $5964.2\;{\mu}/L$) were significantly higher than those in the control (22.6 IU/L, 3.2, $5250.0\;{\mu}/L$; p<0.01, p<0.001, p<0.01). In conclusion, consuming fiber and vegetables may prevent and reduce metabolic syndrome in adult men and women, and this study demonstrates the need for proper dietary management for them.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.488-505
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• 2007

The purposes of this research are twofold; 1) to verify spatial differences of tectonic movement using the spatial distribution of earthquakes, and 2) to infer mechanisms that generate spatial accumulation patterns of earthquakes in the Korean Peninsula. The first part of this sequential paper (Park, 2007) argues that the Korean Peninsula consists of four geostructural regions in which tectonic deformation and consequent geomorphological development patterns are different from each other Since this conclusion has been made by terrain analyses alone, it is necessary to verify this suggestion using other independent geophysical data. Because earthquakes are results of movement and deformation of land masses moving in different directions, the distribution of earthquake epicenters may be used to identify the direction and rates of land mass movement. This paper first analysed the spatial distribution of earthquakes using spatial statistics, and then results were compared with the spatial arrangement of geostructural regions. The spatial distribution of earthquakes in the Korean Peninsula can be summarized as the followings; firstly, the intensity of earthquakes shows only weak spatial dependency, and shows large difference even at adjacent regions. Secondly, the epicenter distribution has a clear spatial accumulation pattern, even though the intensity of earthquake shows a random pattern. Thirdly, the high density area of earthquakes shows a clear 'L' shape, passing through Pyeongannam-do, centered at Pyeongyang, and Hwanghae-do, Seosan and Pohang. The correlation coefficient between the density of earthquakes and distance from geostructral region boundaries is much higher than those between the density of fault lines and distance from tectonic division boundaries. Since fault lines and tectonic divisions in the Korean Peninsula are the results of long-term geological development, there is an apparent scale discrepancy to find significant correlations with earthquakes. This result verifies the research hypothesis that the Korean Peninsula is divided into four geostructral regions in which each has its own moving direction and spatial deformation characteristics. The existence of geostructural regions is also supported by the movement parrerns of land masses estimated from the GPS measurements. This conclusion is expected to provide a new perspective to understand the geomorphological developments and the earthquake occurrences in the Korean Peninsula.

• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.125-133
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• 2016

Sharks (Selachii) comprising about 510 valid species worldwide. Forty-three shark species belonging to 30 genera, 19 families and 8 orders have been found in Korean coastal waters, and all these are registered at the IUCN Red List as followings: endangered (EN) 1 species (2.3%) (vs. worldwide 15 spp., 3.2%), vulnerable (VU) 11 spp. (25.6%) (vs. 48 spp., 10.3%), near threatened (NT) 10 spp. (23.3%) (vs. 67 spp., 14.4%), least concern (LC) 9 spp. (20.9%) (vs. 115 spp., 24.7%), data deficient (DD) 12 spp. (27.9%) (vs. 209 spp., 44.9%), and critically endangered (CR) absent (vs. 11 spp., 2.4%). Twelve species among 43 sharks distributing in Korean waters are assessed as Threatened in the IUCN Red List categories and criteria as followings: Sphyrna lewini (EN, A2bd+4bd), Rhincodon typus (VU, A2bd+3d), Cetorhinus maximus (VU, A2ad+3d), Carcharodon carcharias (VU, A2cd+3cd), Isurus oxyrinchus (VU, A2abd+3bd+4abd), Alopias pelagicus (VU, A2d+4d), A. vulpinus (VU, A2bd+3bd+4bd), Carcharhinus plumbeus (VU, A2bd+4bd), S. zygaena (VU, A2bd+3bd+4bd), Squalus suckleyi (VU, A2bd+3bd+4bd), Squatina japonica (VU, A2d+4d), and S. nebulosa (VU, A2d+4d). Eighteen chondrichthyan species are registered in the list of the CITES Appendices, among them five sharks are distributing in Korean waters as Appendix II, i.e., R. typus, C. maximus, C. carcharias, S. lewini and S. zygaena. The scientific name of "Gobsangeo" has been changed from Squalus acanthias of the North Pacific to S. suckleyi, and "Mojorisangeo" from S. megalops of the Northwest Pacific to brevirostris.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.6
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• pp.13-22
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• 2012

This study was conducted to establish ecotourism as an introduction to sustainability and international cooperation. As a plan to retain the original meaning of ecotourism, the introduction of a program to certify/designateecotourism is being vitalized in many countries around the world. In Korea as well, an agenda to the introduction of an "Ecotourism Designation System,"which aims to ensure the quality of ecotourism at a certain level, was submitted by the Ministry of Environment to the National Assembly in June 2011, and the promotion for a demonstration program is planned this year to introduce the system. Japan has been carrying out the certification systems Good Eco-tour, which certifies the sustainability of ecotourism providers and accommodations since 2006, respectively, and has been securing the sustainability of ecotourism by enactment in 2008, as the world's first law to promote ecotourism. And the second general conference of the first Global Partnership for Sustainable Tourism(GPST) was held in Korea in March 2012, particularly, there was an agreement that the promotion of Asia and the Pacific Area Network for sustainable tourism would center around Korea, and accordingly, it is expected that Korea's status as a core country for ecotourism in the Asia-Pacific Area will increase. While the demand for an approach to natural resources is rapidly increasing, we should be active in providing an institutional strategy such as a designation system to secure the sustainability of ecotourism and seeking a plan for cooperation and network vitalization in the Asia-Pacific Area where similar natural resources and cultures are shared.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.64-73
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• 2015

The distributions of Pb and Cd concentrations in the surface seawater of the East Sea were investigated during the R/V Lavrentyev cruise (July 2009) in which four transects from Russia shore to South were conducted to collect 26 surface water samples. The total dissolved concentrations of Pb and Cd were measured using ICP-MS (Perkin Elmer, DRC-e). In the coastal area, their concentrations of Russia shore (Pb, 0.08; Cd, 0.10 nM) were comparable for Cd but on the other hand, 6 times lower for Pb than Korea shore (Pb, 0.49; Cd, 0.11 nM). In the subregion, their concentrations of Warm region (Pb, 0.22; Cd, 0.01 nM) were about 1.7 times higher for Pb but 0.4 lower for Cd than Cold region (Pb, 0.13; Cd, 0.14 nM). The distributions of Pb and Cd concentrations were divided by lowest level at $10^{\circ}C$ of water temperature. Below $10^{\circ}C$, Pb and Cd concentrations increased when surface water temperatures decreased. Above $10^{\circ}C$, their concentrations increased with temperature, which showed highest concentrations in the Ulleung basin, directly influenced by flux from East Korean Warm Current and neighboring countrys (Korea and Japan). Specially, in the case of Pb, the concentrations decrease remarkablely with temperatures decrease from D10 directly influenced by flux from East Korean Warm Current, which shows highest Pb level. By comparing with other sea areas (Western Mediterranean, East Pacific), Pb concentrations in the East Sea were a little higher. The influence of East Korean Warm Current and neighboring countrys (Korea and Japan) may be relatively important. Therefore, the distribution of Cd may primarily be influenced by mixing of different water masses while the distribution of Pb may mainly be influenced by flux from East Korean Warm Current and atmospheric inputs. River inputs and interaction with particulate materials may also some roles for the distribution of these elements.

• Korean Journal of Remote Sensing
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• v.36 no.5_3
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• pp.1037-1051
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• 2020

The accurate monitoring and forecasting of the intensity of tropical cyclones (TCs) are able to effectively reduce the overall costs of disaster management. In this study, we proposed a multi-task learning (MTL) based deep learning model for real-time TC intensity estimation and forecasting with the lead time of 6-12 hours following the event, based on the fusion of geostationary satellite images and numerical forecast model output. A total of 142 TCs which developed in the Northwest Pacific from 2011 to 2016 were used in this study. The Communications system, the Ocean and Meteorological Satellite (COMS) Meteorological Imager (MI) data were used to extract the images of typhoons, and the Climate Forecast System version 2 (CFSv2) provided by the National Center of Environmental Prediction (NCEP) was employed to extract air and ocean forecasting data. This study suggested two schemes with different input variables to the MTL models. Scheme 1 used only satellite-based input data while scheme 2 used both satellite images and numerical forecast modeling. As a result of real-time TC intensity estimation, Both schemes exhibited similar performance. For TC intensity forecasting with the lead time of 6 and 12 hours, scheme 2 improved the performance by 13% and 16%, respectively, in terms of the root mean squared error (RMSE) when compared to scheme 1. Relative root mean squared errors(rRMSE) for most intensity levels were lessthan 30%. The lower mean absolute error (MAE) and RMSE were found for the lower intensity levels of TCs. In the test results of the typhoon HALONG in 2014, scheme 1 tended to overestimate the intensity by about 20 kts at the early development stage. Scheme 2 slightly reduced the error, resulting in an overestimation by about 5 kts. The MTL models reduced the computational cost about 300% when compared to the single-tasking model, which suggested the feasibility of the rapid production of TC intensity forecasts.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.190-204
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• 2018

The probability of safe cropping and the major phenological stages in rice were assessed using daily mean temperature data from 1981 to 2016 at 27 sites in North Korea. The threshold temperatures for early marginal transplanting date (EMTD), marginal harvesting date (MHVD), safe marginal heading date (SMHD), and cumulative temperature-based heading date (CTHD) were set to be $14^{\circ}C$, $13^{\circ}C$, $22^{\circ}C$ for 40 days after heading, and cumulative temperature of $1200^{\circ}C$ to MHVD, respectively. The safe heading date (SHD) was assumed to be either SMHD or CTHD whichever was earlier. It was also assumed that the minimum requirement for the suitability of safe rice cropping was met when both SMHD and CTHD appeared along with the time period of 60 days or more from EMTD to SHD. It was analyzed that 17 sites (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, Pyongyang, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Huichon, Supung, Kanggye) had 90% or higher probability, two sites (Yangdok, Sinpo) had 80-90% probability, and eight sites (Kimchaek, Chunggang, Chongjin, Sonbong, Changjin, Pungsan, Hyesan, Samjiyon) had less than 80% probability of the safe rice cropping. For each region, the representative EMTD, SHD, and MHVD were analyzed using the 80 percentile of total years tested. The ranges for EMTD, SHD, and MHVD were May 4 in Sariwon~May 24 in Sinpo, June 21 in Kanggye~August 11 in Haeju, and September 17 in Kanggye~October 16 in Haeju and Changjon, respectively. Time durations from EMTD to SHD and from SHD to MHVD were 67~97 days and 57~72 days, respectively, depending on the regions. This study would facilitate modeling efforts for rice yield simulation in future studies. Our results would also provide basic information for practical researches on the rice cropping system in North Korea.

• Analytical Science and Technology
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• v.23 no.4
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• pp.371-382
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• 2010

TSP and PM2.5 atmospheric aerosols have been collected at Gosan site of Jeju Island, and their compositions were analyzed to understand the pollution characteristics. The composition ratios of nss (non-sea salt)-$SO_4^{2-}$ and $NH_4^+$ were higher in Gosan site than those in other Korean background and urban sites. However the composition ratio of $NO_3^-$ was conversely lower in Gosan site. From the study of aerosol components according to particle sizes, the anthropogenic nss-$SO_4^{2-}$, $NO_3^-$ and $NH_4^+$ components were mostly existed in the fine particles. But the nss-$Ca^{2+}$, $Na^+$, $Cl^-$ and $Mg^{2+}$ originated from soil and marine sources were distributed relatively in the coarse particles. In the seasonal comparison, the concentrations of nss-$Ca^{2+}$, Al, Fe, Ca and $NO_3^-$ increased in spring season, and nss-$SO_4^{2-}$ showed higher concentration in summer and spring seasons. Based on the factor analysis, the atmospheric aerosols in Gosan site have been found to be influenced largely by anthropogenic sources, and next by marine and soil sources. The backward trajectory analyses showed that the concentrations of nss-$SO_4^{2-}$, $NO_3^-$, Pb and nss-$Ca^{2+}$ increased when the air mass moved from Chinese continent to Jeju area. On the other hand, their concentrations decreased when the air mass moved in from the North Pacific Ocean.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.31-39
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• 2009

This study has found that there is a reverse phase with interdecadal variation in temporal variations of tropical cyclone (TC) genesis frequency (TCGF) between Northwest sector and Southeast sector, based on climatological mean tropical cyclone genesis location over the western North Pacific. The TCGF in the Northwest sector has been increased since the mid 1980s (1986-2005), while TCGF in the Southeast sector was higher until the early 1970s (1951-1970). The analysis of a difference between 1986-2005 and 1951-1970 showed results as follows: i) Through the analysis of vertical wind shear (VWS) and sea surface temperature (SST), less VWS and higher SST in the former (latter) period was located in the Northwest (Southeast) sector. ii) In the analysis of TC passage frequency (TCPF), TCs occurred in the Northwest sector frequently passed from east sea of the Philippines, through East China Sea, to Korea and Japan in the latter period, while TCs in the former period frequently has a lot of influences on South China Sea (SCS). In the case of TCs occurred in the Southeast sector, TCs in the west (east), based on $150^{\circ}E$ had a high passage frequency in the latter (former) period. In particular, TCs during the latter period frequently moved toward from the east sea of the Philippines to SCS and southern China. iii) This difference of TCPF between the two periods was characterized by 500 hPa anomalous pressure pattern. Particularly, anomalous cyclonic circulation strengthened over the East Asian continent caused anomalous southerlies along the East Asian coast line from the east sea of the Philippines to be predominate. These anomalous winds served as steering flows that TC can easily move toward same regions.