• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.193-204
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• 2004

This study was conducted to evaluate both temporal and spatial dynamics of phytoplankton community and environmental parameters in a newly made reclaimed esturine lake (L. Hwaong). Monthly sampling was conducted at 4 sites covering the longest transect of longitudinal gradient of the lake from June to November, 2002. Total 5 classes 8 orders 26 families 83 genus 192 species were identified at all study sites during the study period. Phytoplankton total cell density ranged 24${\sim}$ 1,882 cells $mL^{-1}$ and highly varied both temporally and spatially. Total cell density was significantly related with salinity, pH, BOD, COD, SS, TN and TP concentration. Diatom density also was significantly correlated with salinity, SS, BOD, COD and TN concentration, Although there was spatial difference, a longtudinal gradient appeared in phytoplankton cell density, Chl-a, TN and TP concentration from the mouth of river in June and August. In conclusion, phytoplakton community structure was dominated by diatoms (Bacillariophyceae), and appeared to be largely influenced by salinity, precipitation, and nutrients during the summer and the fall.

• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.1
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• pp.12-17
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• 2017

This study established ecological goals and success criteria by using results of the coastal ecosystem restoration demand survey. The ecological goals are set for species diversity, regulation of seawater flow, improvement of purification, erosion prevention and habitat provision by ecosystem types. The indicators of success criteria are chosen the number of emergence species and community characteristics of target organism and pertinent items of hydrologic, water quality and sediment environment by ecological goals among the investigation items of tidal flat investigation guideline.

• Journal of the Korean earth science society
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• v.21 no.2
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• pp.159-167
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• 2000

We tested the randomness and estimated the degree of concentration for the earthquake occurrence in the Korean Peninsula by using the statistical methods for spatial data. For the randomness test, we applied both of the test statistics based method and the empirical distribution based method to the both of historical and instrumental seismicity data. It was found that the earthquake occurrences for historical and instrumental seismicity data are not random and clustered rather than scattered. A nonparametric density estimation method was used to estimate the concentration degree in the Peninsula. The earthquake occurrences show relatively high concentration on Seoul, Choongnam, Chonbook and Kyungbook areas for the historical seismicity data. Also,'L" shaped concentrations connecting Whanghaedo -the coast of Choongnam -the inland of Kyungbook area are revealed for the instrumental seismicity data.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.79-90
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• 2016

This study investigates seasonal variation and spatial distribution of meiobenthic community of Gamak Bay (one of the major bays of southern coastal area of Korea). Total of 6 surveys of 10 stations took place, once in February, June and October of 2009 and through 2010. Community structure, taxon diversity (H') and nematodes/copepods ratio of meiobenthos were studied in Gamak Bay. During the study period, nematodes and harpacticoids were the most dominant taxa among the meiofaunal groups in Gamak Bay. Taxon diversity (H') was the highest at the outer stations and the lowest at the inner stations in the Gamak Bay. The nematodes/copepods ratio was seasonally studied as an index of pollution monitoring for the benthic ecosystem at each station. As a result, nematodes/copepods ratio was the highest at the inner stations and the lowest at the outer stations in Gamak Bay.

• Health Policy and Management
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• v.29 no.3
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• pp.312-322
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• 2019

Background: Since 2003, Korea has consistently shown the highest suicide rate among the Organization for Economic Cooperation and Development countries, and suicide remains the major cause of death. In particular, men are 2-3 times more likely to commit suicide than women, which called the 'gender paradox of suicide.' The areas with frequent suicide have spatially clustered patterns because suicide with a social contagion spreads around the neighborhood. The purpose of this study was twofold. The first was to estimate the hotspot areas of age-standardized male suicide mortality from 2008 to 2015. The second was to analyze the relationship between the hotspot areas and the regional characteristics for study years. Methods: The data was collected through the Korean Statistical Information Service. The study areas were 227 si gun gu administrative districts in Korea. The hotspot area was used as a dependent variable. Socio-demographic variables (number of marriages per 1,000 population, number of divorces per 1,000 population, and urbanization rate), financial variables (financial independence and social security budget), and health behaviors (EuroQol-5 dimension [EQ-5D], and depression experience rate) were used as independents variables. Results: The hotspot areas were commonly located in Gangwon-do, Chungcheongnam-do, Gyeongsangbuk-do, and Chungceongbuk-do. According to the results of panel logit regression, the number of divorces per 1,000 population, social security budget, and EQ-5D were statistically significant variables. Conclusion: The results of hotspot analysis showed the need for establishing a prevention zone of suicide using hotspot areas. Also, medical resources could be considered to be preferentially placed in the prevention zone of suicide. This study could be used as basic data for health policymakers to establish a suicide-related policy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.909-916
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• 2006

This study investigates tourists' sightseeing excursion behaviors and their information usage patterns at Fuji five lakes Area. This paper aims to empirically analyze the relationship between a sightseeing excursion behavior and use of tourist information applying a cluster analysis and a quantitative regression model. The main results are summarized as follows: (1) Tourists' information need is high about 90% of all tourists get information, 80% get the information before travel, 70% on the journey, 60% at the same time. (2) The patterns of information usage are categorized into 3 groups by the timing when tourists try to get the information.(3) There exists a difference among the time-spatial characteristics of excursion's behaviors such as the time after arriving time at sightseeing area, the time till go to home, duration time, and the total travel time between spots, the number of spots, and the size of excursion scale. (4) The quantitative regression model shows that information usage which constrained by time and space significantly determines both the number of the sightseeing spots and the duration time.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.275-287
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• 2013

The Japanese anchovy Engraulis japonicus is a widespread species in the western North Pacific and major fishery resource. To understand the spatio-temporal variation of anchovy prey items in the coastal waters of southern Korea, the stomach contents of anchovy and the structure of the zooplankton community were analysed at three sites (Jindo, Yeosu and Tong-yeong) from July 2011 to February 2012. The main prey items in Yeosu and Jindo were cyprid stage of barnacle (>35%) and copepod Calanus sinicus (>22%) in July, respectively, while, predominant ones in Tongyeong were small copepods, Paracalanus parvus s.l. (41%) and Corycaeus affinis (22%). During this period, the dominant zooplankton were cladoceran Evadne tergestina (39%) in Yeosu, small copepod, P. parvus s.l. (28%) in Jindo and cladoceran E. tergestina (14%) in Tongyeong. The dominant prey items were barnacle larvae and copepods in summer, phytoplankton and Pseudodiaptomus marinus in autumn and P. parvus s.l. and cold water copepod, Centropages abdominalis in winter. Anchovy prefer the prey item C. sinicus (3%) over E. tergestina (39%), which was a dominant species in the catching site in summer. P. marinus (0.5%) and C. abdominalis (0.9%) were preferred over P. parvus s.l. (30%, 21%) in autumn and winter, respectively. Prey items varied with area and season in the coastal waters of southern Korea. These results suggest that the prey selectivity of anchovy showed high flexibility and adaptability in the study waters.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.378-385
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• 2016

This study aims to suggest the framework of functional assessment on lotic area based on HGM(Hydrogeomorphic) approach targeting Wetland Protected Areas which are in the type of river channel, and to set up the fundamental data as a reference wetland. A total of 10 factors in terms of hydrology, biogeochemistry, plant habitat and animal habitat was analyzed based on the original approach of HGM and each Functional Capacity Index(FCI) of those factors was calculated. As the result of the modified FCI analysis, Damyang riverine wetland which is with artificial river bank had high values in the variables of area ratio of actual vegetation in the foreland, the number of plant per area and the area ratio of Salix spp., and those values were highly reflected on the factors of Nutrient Cycling(947,668.00), Species Richness and Maintain Characteristic Plant Communites(6.39) and Maintain Spatial Structure of Habitat(11.00). The Hanbando wetland which is keeping the natural bank had higher values in the variables of structural scale and species diversity, and the those values were highly reflected on the factors of Energy Dissipation(17,805.16), Subsurface Storage of Water(0.54), Removal of Imported Elements and Compounds(103,052.73), Maintain Characteristic Detrital Biomass(2.31), Maintenance of Interspersion and Connectivity (6.50), Species Diversity of Benthic macro-invertebrates(1.60) and Species Diversity of Vertebrate & Species Number of Other Animals(2.52/ 151.50), compared to the Damyang Riverine Wetland.

• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.31-44
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• 2012

Seasonal changes in groundwater geochemistry exist in Ddan-sum island. In the farming season of April, the spatial distribution of ions explains that $Fe^{2+}$, Fe(total), $Mn^{2+}$, $Ca^{2+}$, $Mg^{2+}$, $SiO_2$, ${HCO_3}^-$, and ${NO_3}^-$ are high in the center of the island, but $Na^+$ and $K^+$ are relatively low and these high anions indicates the effect of fertilizer used for strawberry cultivation. Spatial variation of ion concentration is smaller in August than April because of low agricultural activity and heavy rainfall. Geochemical type of groundwater shows that the center of island has the characteristics of recharge zone but the rim area corresponds to a mixing zone between groundwater and stream water. According to the analysis of saturation index for Fe and Mn ions, hematite, goethite, and rhodochrosite under supersaturation have a possibility of additional mineral deposition, and siderite, $Fe(OH)_3$, manganite, pyrolusite, and pyrochroite under unsaturation may exist as a type of dissolved ion.

• Spatial Information Research
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• v.23 no.5
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• pp.1-7
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• 2015

Twitter has the fast propagation and diffusion of information compare to other SNS. Therefore, many researches about detecting real-time event using twitter are progressing. Twitter real-time event detecting system assumes every twitter user as a sensor and analyzes their written tweet in order to detect the event. Researches that are related to this twitter have already obtained good results but confronted the limits because of some problems. Especially, many existing researches are using the method that can trace an event location by using GPS coordinate. However, it can be suggested a definite limitation through the present user's skeptical responses about making personal location information public. Therefore, this paper suggests the method that traces the location information in tweet contents text without using the provided location information from twitter. Associated words were grouped by using the keyword that extracted in tweet contents text. The place that the events have occurred and whether the events have surely occurred are detected by this experiment using this algorithm. Furthermore, this experiment demonstrated the necessity of the suggested methods by showing faster detection compare to the other existing media.