• Korean Business Review
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• v.11
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• pp.241-253
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• 1998

One form of the anomalies of stock price changes as reaction to earnings information is believed to be caused by the so-called earnings fixation, which is the overreaction of stock prices to earnings. According to the Sloan (1996) study, stock price changes are positively associated with earnings at the time of earnings releases, but the association becomes negative after that, as the early overreaction is corrected. However, the problem in his study is to use cash flows computed by adjusting earnings with appropriate income statement and balance sheet items. As Bahnson et al. (1996) show, these cash flows substantially deviate from SFAS No. 95 cash flows and the sample used in this study is found to be subject to this substantial measurement error. Therefore, the result of Sloan might be driven by this error and the reexamination of earnings fixation is warranted. The results are generally consistent with those in Sloan. First, earnings is positively associated with stock price changes at the time of earnings releases, but the association becomes negative after that. Second, cash flows show a weak association with stock price changes at the time of earnings releases, but the association become stronger thereafter. Third, when seperated from cash flows, accruals have an incremental explanation about stock price changes beyond that of cash flows, accruals have a negative association later on. This finding is consistent with stock price overreaction to accruals, even when more cleaner cash flow data are used.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.76-91
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• 2016

The purpose of this study is to analyze the effects of spatial characteristics, such as land cover and topography, on heat wave days from the city of Milyang, which has recently drawn attention for its heat wave problems. The number of heat wave days was calculated utilizing RCP-based South Korea climate data from 2000 to 2010. Land cover types were reclassified into urban area, agricultural area, forest area, water, and grassland using 2000, 2005, and 2010 land cover data constructed by the Ministry of Environment. Topographical features were analyzed by topographic position index (TPI) using a digital elevation model (DEM) with 30 m spatial resolution. The results show that the number of heat wave days was 31.4 days in 2000, which was the highest, followed by 26.9 days in 2008, 24.2 days in 2001, and 24.0 days in 2010. The heat wave distribution was relatively higher in agricultural areas, valleys, and rural areas. The topography of Milyang contains more mountainous slope (51.6%) than flat (19.7%), while large-scale valleys (12.2%) are distributed across some of the western region. Correlation analysis between heat wave and spatial characteristics showed that the correlation between forest area land cover and number of heat wave days was negative (-0.109), indicating that heat wave can be mitigated. Topographically, flat areas and heat wave showed a positive correlation (0.305). These results provide important insights for urban planning and environmental management for understanding the impact of land development and topographic change on heat wave.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.374-387
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• 2020

This study was conducted to provide basic data for monitoring the trend of ecosystem change and establishing management plans for wetland protection areas by understanding the status of naturalized plants. In 21 wetland protection areas, 129 taxa, including 10 invasive alien species, were recorded. The naturalized plants appeared mostly as 71 taxa in the Chimsil wetland and were not observed in the Moojechineup and Sumeunmulbaengdui wetlands. Among the naturalized plants, 42 taxa (32.6%) originated from North America. Annual and biennial plants accounted for 68.2% (88 taxa). The frequencies of occurrence of naturalized plants growing in dry secondary grasses such as Erigeron annuus and Trifolium repens were high, and clonal plants that propagated by making stolons and struck roots accounted for 19.4% (25 taxa). The naturalized and urbanization indices showed positive correlations with location factors such as wetland, agricultural land, and used area. However, a negative correlation was found between altitude and forest. Therefore, a management plan that synthetically considers the occurrence frequency and growth characteristics of naturalized plants as well as the locational characteristics of wetland protection areas is required.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.274-285
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• 2016

In order to elucidate the spatiotemporal variations of marine environmental parameters, we collected seawater samples in the middle east coast of Korea in 2013-2014. A high temperature and low salinity were distinctively observed in the summer and a low temperature and high salinity pattern in the winter. The temperature of the bottom water was in the range of $2^{\circ}C$ to $7^{\circ}C$, with the temperature being relatively high in the winter, while the salinity was measured to be around 34, with no large differences across the seasons. The dissolved oxygen concentrations were in the range of $7mg\;L^{-1}$ to $12mg\;L^{-1}$, and it was relatively high in May compared to other seasons. The seawater temperature and dissolved oxygen concentration at the surface layer showed a significant negative correlation in the autumn and winter seasons, based on which it is seemed that water temperature is the main factor controlling the amount of dissolved oxygen in the autumn and winter seasons. The dissolved inorganic nitrogen (DIN) and silicate (DSi) increased 11- and 7-fold, respectively, in the winter compared to the summer. The DIN to DIP (dissolved inorganic phosphorus) ratio for the surface seawater was approximately 16, but it was relatively low in the spring season. On the other hand, the DIN to DIP ratio was relatively high in the summer. Based on this, it is seemed that nitrogen and phosphorus were the growth-limiting nutrients for phytoplankton in the spring and summer, respectively. Water quality was I (excellent) ~III (medium) level at the most stations except for some stations (level IV) during the autumn season, having low dissolved oxygen saturations.

• Korean journal of applied entomology
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• v.56 no.1
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• pp.29-39
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• 2017

To compare the features of ground-dwelling invertebrates according agroecosystems, we selected paddy fields, dry fields, orchards in the Eastern region of Korea. The surveys were performed by using pit-fall traps twice per year from 2013 to 2015. Total 6,420 individuals of 172 species belonging to 13 orders, 58 families were investigated in the Eastern region, the species of Hymenoptera (38.26%), Orthoptera (16.28%) accounted large portion of the communities. In the geographical observation, invertebrates were caught was 2,983 individuals in Gyeongsangnam-do, the diversity index of Gyeongsangbuk-do community was higher than of the others and abundance and species richness of paddy field were higher than from dry field or orchard. To understand the relation between taxonomic groups and environmental factors, we carried out the canonical correspondence analysis and hierarchical clustering. As a result, Homoptera, Blattaria, Isoptera, and Coleoptera were positively related to soil pH, soil temperature, and moisture contents, and negatively related to the others. Invertebrate community also were patterned dependently by type of ecosystems. This results were shown that distribution of invertebrates is a few influenced the relationship of the space habituated invertebrates and environmental factors.

• Economic and Environmental Geology
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• v.34 no.1
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• pp.105-117
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• 2001

The characteristics of hydrogeochemistry and fluorine distribution in drinking groundwater from limestone and granite were studied in the Keumsan-Wanju area, where major important fluorite-deposits are distributed. The hydrochemical properties of groundwater from studied area arc commonly characterized as $Ca-HC0_3$ water type. However, some of the groundwater samples collected from Jurassic and Cretaceuus granites belong to $Ca-Na-HC0_3 and Na-HC0_3$ type, respectively. The contamination of drinking groundwater by minewater from the nearby fluorite deposits is not found yet. However, groundwater having high F contents up to 1].4 mgll, which is higher than the drinking water limit, is found from the wells located in Cretaceous granite. The tluorine contents in groundwater generally increase with increasing well depth. The concentrations of F in the groundwater show a positive relationship with the values of Na, $HC0_3, Cl. Si0_2$, pH, whereas a negative relationship with Ca. The positive correlation of F-concentrations to major elements ($Si0_2$, Na, CI) and trace elements (Li, B, Rb) may suggest that the groundwater come from the decomposition of tluoride-bearing silicate minerals within highly differentiated granitic rocks, Therefore, wells for drinking water should not be developed or should be drilled within shallow level in the Cretaceous granite region to reduce the F contents in the groundwater.

• Korean Journal of Ecology and Environment
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• v.45 no.2
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• pp.174-189
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• 2012

The objective of this study was to determine the weight-length relations and condition factor (K) of Zacco platypus, along the trophic gradients from oligotrophic to eutrophic state in six reservoir ecosystems ($B_aR$, $Y_yR$, $J_yR$, $G_pR$, $Y_dR$, and $M_sR$), during 2008~2010. The species was selected as a sentinel species for the study, due to its wide distribution and wide trophic gradient. The analysis of trophic state index (TSI), based on total phosphorus (TP) and chlorophyll-a (Chl-a), indicated that reservoirs of $Y_yR$ and $B_aR$ were classified as to be in an oligotrophic state (30~40), the $J_yR$ and $G_pR$ as mesotrophic (40~50), and the $Y_dR$ and $M_sR$ as eutrophic state (50~70). Total 47 species and 26,226 individuals were sampled from 6 reservoirs and sensitive species dominated in the oligotrophic reservoirs ($Y_yR$ and $B_aR$). In the mean time, the tolerant speciesdominated the community in the mesotrophic ($J_yR$ and $G_pR$) and eutrophic ($Y_dR$ and $M_sR$) reservoirs. Regression analysis of body weight, against the total length, indicated that the regression coefficient (b value) was lower in the oligotrophic reservoir (2.77~2.79) than the mesotrophic (3.07~3.17) and eutrophic reservoirs (3.15~ 3.21). This result suggests that the population growth rate Zacco platypus reflected the trophic gradients of the reservoirs. The analysis of condition factor (K) against the total length showed positive slopes (b>3.0) in mesotrophic and eutrophic reservoirs, and a negative slope (b<3.0) in oligotrophic reservoir. The variation of the regression slope of "b" in Z. platypus was accounted for 79.7% [$b=0.012{\times}TSI(TP)+2.395$, p=0.017] by the variation of TSI (TP) and 82.2% [$b=0.013{\times}TSI(Chl-a)+2.36$, p=0.013] by the variation of TSI (Chl-a). The proportion of DELT abnormality increased as the trophic state increases in the reservoirs. The overall data suggest that the growth of the fish populations, based on the length-weight relations and condition factor, reflected the trophic state of nutrient and phytoplankton biomass of the reservoir waters. Thus, in spite of the tolerant characteristics of Z. platypus, hypertrophic states might negatively affect the health of the population.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.1
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• pp.44-54
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• 2001

This study was conducted to estimate microclimate of natural deciduous forest in national forest of Pyungchang, Kangwon province and to investigate the effects of the microclimatic conditions on the periodic annual increment of diameter by site types. In this study, site was first classified by nine types considering both elevation (higher than 1,000 m, 700∼1,000 m, and lower than 700 m) and topographical conditions (ridge, slope and valley). For each of site types, diameter growth was measured by using increment borer and periodic annual increment of diameter was then analyzed. A topoclimatological technique, for estimating microclimatic conditions, which make use of empirical relationships between the topographical factor and the climatic normals in the study area was applied to produce monthly mean, maximum and minimum temperatures, relative humidity, precipitation and hours of sunshine. From these monthly estimtes, 17 weather variables such as warmth index, coldness index, index of aridity etc. which affect the diameter growth were computed for each of site types. The periodic annual increment of diameter was then correlated with and regressed on the 17 weather variables to examine effects of microclimatic conditions on the diameter growth by site types. From the correlation analysis, it was found that the diameter growth by site types was positively correlated with all of 17 weather variables except the warmth index. Especially, the conditions such as high relative humidity and large amount of sunshine hours provide favorable environment for the growth of diameter. On the other hand, it was also found that diameter growth was negatively iufluenced by warmth index. According to the regression analysis, the periodic annual increment of diameter could be well predicted by index of aridity and mean relative humidity for the growing season.

• Journal of the Mineralogical Society of Korea
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• v.18 no.4 s.46
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• pp.277-288
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• 2005

Perlite, a hydrated volcanic glass, occurs mainly as a bed-like body, and is distributed intermittently along the unconformity surface between the Beomgockri Group and its lower formations, viz. Janggi Group. The perlite is intimately associated with surrounding pumiceous welded tuff and rhyodacites in space and time. Compared to the typical perlite, the perlite is rather silica-poor and impure, and thus, includes lots of phenocrysts and rock fragments. Nearly the perlite is compositionally rather close to a pitchstone than a perlite in water contents. Petrographic comparison between perlite and associated volcanic to volcaniclastic rocks indicates that pumiceous welded tuff and rhyodacite seem to be Protolith of the Perlite. A Zr/$TiO_{2}$-Nb/Y diagram and field occurrence of perlite and their protolithic rocks also conforms the above interpretation. Kn addition, remnant vesicles in perlite strongly reflect that the precursor of perlitic glass appeared to be pumice fragment as well as volcanic glass. The perlite was diagenetically formed by way of a pervasive water-rock interaction at the deposition of the Manghaesan Formation in lacustrine environment. During perlitization, $SiO_{2}$ and alkali tend to be consistently depleted. Preexisting system of the Beomgockri Group based on the perlite formation should be corrected, because the perlite was formed diagenetically without lateral persistence in its occurrence.

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.1-22
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• 2020

In order to evaluate the vertical distribution and distributional pattern of vascular plants in the Samga district of Sobaeksan National Park, vascular plants were surveyed along a hiking trail from the Samga Tour Support Center to the top of a mountain. The elevation range was divided into 11 sections with 100 m intervals from 400 m to 1439 m above sea level.A total of 375 taxa were listed, comprising 92 families, 235 genera, 332 species, 3 subspecies, 37 varieties, and 3 forms. The pattern of species richness along the elevational gradient showed a reverse hump-shaped trend. The species distribution pattern was positively correlated with the soil exchangeable cations Ca²⁺ and Mg²⁺, soil pH, available phosphate, and the warmth index. Furthermore, slope, soil moisture content, and soil exchangeable cations were significantly correlated with species distribution. DCA grouped herb species into two groups. Stands of each section were sequentially arranged from 400 m to 1500 m along an altitudinal gradient. Soil moisture content, soil pH, soil K²⁺ and Na²⁺, available phosphate, and slope were significantly correlated with stand distribution. This study provides important data that could be useful for conservation and the sustainable use of biodiversity in the study area. In order to understand the ecological and environmental characteristics and distribution of plant species, it will be necessary to continuously develop relative studies with continuous monitoring.