• Korean Journal of Remote Sensing
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• v.36 no.5_3
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• pp.1053-1066
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• 2020

Sulfur dioxide (SO₂) is primarily released through industrial, residential, and transportation activities, and creates secondary air pollutants through chemical reactions in the atmosphere. Long-term exposure to SO₂ can result in a negative effect on the human body causing respiratory or cardiovascular disease, which makes the effective and continuous monitoring of SO₂ crucial. In South Korea, SO₂ monitoring at ground stations has been performed, but this does not provide spatially continuous information of SO₂ concentrations. Thus, this research estimated spatially continuous ground-level SO₂ concentrations at 1 km resolution over South Korea through the synergistic use of satellite data and numerical models. A stacking ensemble approach, fusing multiple machine learning algorithms at two levels (i.e., base and meta), was adopted for ground-level SO₂ estimation using data from January 2015 to April 2019. Random forest and extreme gradient boosting were used as based models and multiple linear regression was adopted for the meta-model. The cross-validation results showed that the meta-model produced the improved performance by 25% compared to the base models, resulting in the correlation coefficient of 0.48 and root-mean-square-error of 0.0032 ppm. In addition, the temporal transferability of the approach was evaluated for one-year data which were not used in the model development. The spatial distribution of ground-level SO₂ concentrations based on the proposed model agreed with the general seasonality of SO₂ and the temporal patterns of emission sources.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.307-318
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• 2010

This study was to analyze the ecological conditions, based on physical habitat, chemical, and biological conditions before (2006, 2007) and after ecological restoration (2009) in five sites of Changwon Stream (CS) and six sites of Nam Stream (NS), respectively, and then to compare ecological health between the two period. The analysis of ecological health was based on the multimetric models of Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) along with water chemistry in the streams. For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. For the evaluations, the survey was conducted in the period of 2006~2007 before the restoration and in 2009 after the restoration by the city. Chemical conditions, based on conductivity, in both streams showed a typical longitudinal declines along the axis of the upstream-to-downstream. There were no significant differences (p>0.05) in water quality between the two periods. Values of IBI in the CS and NS averaged 21.6 and 19.7, respectively, indicating a C grade in the criteria of Ministry of Environment, Korea, and there was no significant differences in the IBI between the two periods. Values of QHEI after the restoration averaged 29.2 and 63.2 in the CS and NS, respectively and the values decreased markedly especially, in the NS (35.3) after the restoration. The habitat disturbance was mainly attributed to destructions (i.e., the narrower width of riparian vegetation and higher substrate exposure by the air) of artificial materials by massive flood in 2009. Overall, our results suggest that the restoration was not effective in the two streams between the two periods, even if the budget was used a lot and that such ecological restoration, not considered the natural disaster, may not effect for the stream restoration.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.141-151
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• 2010

Harmful algal blooms (HABs), commonly known as red tides, are aquatic phenomena caused by the rapid growth and accumulation of certain microalgae, which can lead to marked discoloration of surface waters, and severe impacts on public health, commerce, and the environment. In South Korea, the red tides have been a serious and recurrent problem, especially along the south coast. Plenty of yellow loess was used to control an outbreak of the red tides for 15 years from 1996 until now. Yellow loess was almost sprayed in the vicinity of a large fish farming industry. In this research, the distribution characteristics and density distribution of zooplankton were investigated in autumn (Oct. 2008) and spring (Apr. 2009) using volume backscattering strength (SV) calculated by the zooplankton collected with north pacific standard (NORPAC) net and the echo intensity measured with ADCP at stations on the study area in the spraying ocean of yellow loess (SOYL), and the non-spraying ocean of yellow ocean (NOYL) by the red tide generating every year. The species number and the individuals per unit volume of the zooplankton collected in NOYL was high and it which was collected in SOYL was low. As a result of comparing the volume backscattering strength ($SV_c$) calculated by species and length of the zooplankton collected with NORPAC net with the volume backscattering strength ($SV_m$) calculated by the echo intensity measured with ADCP at stations on the study area, although $SV_c$ and $SV_m$ of NOYL were generally in agreement, $SV_m$ of SOYL was higher than $SV_c$ 4.3dB, i.e. ADCP is greatly influenced by suspended solid in SOYL. The horizontal distribution map of $SV_m$ at the study area in autumn (Oct. 2008) and spring (Apr. 2009) was drawn. $SV_m$ of SOYL is higher than NOYL and autumn is higher than spring. $SV_m$ can suppress the overestimate or underestimate of $SV_c$.

• Fire Science and Engineering
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• v.17 no.1
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• pp.8-20
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• 2003

Natural gas has been supplied through underground pipelines and valve stations as a new city gas in Seoul. In contrast to its handiness the natural gas has very substantial hazards due to fires and explosions occurring from careless treatments or malfunctions of the transporting system. The main objectives of this study are to identify major hazards and to perform risk assessments after assessing reliabilities of the composing units in dealing with typical pipeline networks. there-fore two method, fault tree analysis ;1nd event tree analysis, are used here. Random valve stations are selected and considered its situation in location. The value of small leakage, large rupture, and no supply of liquefied natural gas is estimated as that of top event. By this calculation the values of small leakage are 3.29 in I)C valve station, 1.41 in DS valve station, those of large rup-lure are $1.90Times10_{-2}$ in DC valve station, $2.32$\times$10^{-2}$ in DS valve station, and those of no supply of LNG to civil gas company are $2.33$\times$10 ^{-2}$ , $2.89$\times$10^{-2}$ in each valve station. And through minimal cut set we can find the parts that is important and should be more important in overall system. In DC valve station one line must be added between basic event 26,27 because the potential hazard of these parts is the highest value. If it is added the failure rate of no supply of LNG is reduced to one fourth. In DS valve station the failure rate of basic event 4 is 92eye of no supply of LNG. Therefore if the portion of this part is reduced (one line added) the total failure rate can be decreased to one tenth. This analytical study on the risk assessment is very useful to prepare emergency actions or procedures in case of gas accidents around underground pipeline networks and to establish a resolute gas safety management system for loss prevention in Seoul metropolitan area.

• Journal of Environmental Policy
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• v.8 no.4
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• pp.125-147
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• 2009

The Basic Environmental Policy Act (BEPA) (Law No. 4257 effective 1. August 1990) sets forth the basic policies and administrative framework for environmental preservation, leaving more detailed regulations, and emission controls to separate laws targeting air, water, and solid waste, etc. The BEPA Article 31 adopts an unprecedented strict liability standard for damages as an absolute liability. The BEPA Article 31 provides for liability as follows. If a company is alleged to have caused damage through pollution of the environment, it will be liable for damages unless it can show that the pollution did not cause damages, or that it did not actually cause pollution. If the company did cause pollution, and if the pollution is the cause for the damages in question, the company will be liable irrespective of whether it was negligent or otherwise at fault. If there are two or more companies involved in the pollution, but it is unclear which company caused the damages, all of the companies will be jointly and severally liable for the damages. In this paper, the author attempts to uncover the problems of BEPA Article 31 and then seeks desirable amendments by comparing it to the German Environmental Liability Act. First, it will be necessary to provide definitions of 'companies etc.'. Second, it will be necessary to enumerate the kinds of company facilities. Third, it will be necessary to provide exclusionary clauses on material damages. Fourth, it will be necessary to show 'presumption of cause and effect'. Fifth, it will be necessary to provide a clause on 'right to information'. Sixth, it will be necessary to provide a clause for force majeure. Seventh, it will be necessary to take measures to secure abundant liability for damages which can be caused by the owner of the facility, the potential polluter. Finally, it is appropriate that Korea now legislate an Environmental Liability Act akin to the German Environmental Liability Act.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.181-191
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• 2006

NFI-C null mice demonstrated aberrant odontoblast differentiation and thus abnormal dentin formation while other tissues/organs in the body, including ameloblasts, appear to be unaffected and normal. However little is known about the mechanism of NFI-C function in odontoblast differentiation and dentin formation. Odontoblasts are tall, highly polarized cells that are responsible for formation and maintenance of the predentin and dentin. An indication of their polarity is the acquisition of specialized intercellular junctions. As preodontoblasts differentiate into odontoblasts, they are Joined and attached at the apical end by well developed terminal webs of cytoskeletal actins, and associated tight as well as adherent njunctions. In this study, in order to investigate if disruption of the NFI-C gene interferes with formation of a specific or other structural proteins of the intercellular junctions, we examined morphological characteristic of the aberrant odontoblast in NFI-C null mice using light and electron microscope. In addition, we determined the expression of major structural proteins of intercellular junctions, ZO-1 and occludin, during the differentiation of odontoblasts using immunohitochemistry. The results were as follows : 1. In light microscopy, abnormal odontoblasts of incisors of the NFI-C null mice were round in shape, lost their polarity, and trapped in osteodentin-like mineralized tissue. Mutant molars have relatively normal crowns, but short and abnormal differentiating adontoblasts in root formation area. 2. Electron microscopy of abnormal odontoblasts revealed the dissociation of the round osteoblast-like cells, the loss of their cellular polarity, and the absence of an intercellular junctional complex known as the tight junctions. 3. A mutant incisor showed labeling for ZO-1 at the proximal and distal ends of secreting ameloblasts, while staining for ZO-1 was not observed in the abnormal odontoblasts. 4. A normal incisor showed immunoreactivity for occludin in the differentiating odontoblasts. However, staining for occludin was not observed in the abnormal odontoblasts of mutant incisor. These results suggest that NFI-C gene causes dissociation of odontoblast and thus abberant odontoblast differentiation and abnormal dentin formation by interfering with the formation of intercellular junctions.

• Sleep Medicine and Psychophysiology
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• v.19 no.2
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• pp.84-88
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• 2012

Introduction: The objective of the present study was to investigate the independent effects of major depressive disorder (MDD) and insomnia on somatization, respectively. Methods: A total of 181 participants (73 males and 108 females ; mean age $41.59{\pm}8.92$) without serious medical problem were recruited from a community and a psychiatric clinic in Republic of Korea. Subjects were divided into 4 groups based on the Structured Clinical Interview for DSM-IV axis I disorder (SCID-IV) and sleep questionnaire : 1) normal controls (n=127), 2) primary insomnia (n=11), 3) MDD without insomnia (n=14), and 4) MDD with insomnia (n=29). All participants were requested to complete the somatization subscores of the Symptom Checklist-90-Revised (SCL-90-R). Results: There were significant between-group differences in somatization score (F=25.30, p<0.001). Subjects with both MDD and insomnia showed higher somatization score compared to normal control (p<0.001), subjects with primary insomnia (p=0.01), or MDD subjects without insomnia (p<0.001). Subjects with primary insomnia had higher somatization score than normal controls (p<0.01), while there was no significant difference between MDD subjects without insomnia and normal controls. In multiple regression, presence of insomnia predicted higher somatization score (beta=0.44, p<0.001), while there was only non-significant association between MDD and somatization (beta=0.14, p=0.08). Conclusion: In the current study, insomnia was associated with somatization independently from major depression. Subjects with primary insomnia showed higher somatization. Within MDD patients, presence of insomnia was related to higher somatization. Our finding suggests that insomnia may partly mediate the relationship between depression and somatization.

• Journal of Plant Biology
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• v.3 no.2
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• pp.6-18
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• 1960

The present experiments were designed in order to clarify the differences between the long and short styled plants and the transgressive gradition in the degree of dimorphism among the three heterostylous species of the Polygonus, P. japonica, F. esculentum, and P. senticosa, based on investigations regarding the floral structure, ecological and physiological traits, the results of which are summarized as follows: (1) P. japonica, although it exhibits typical dimorphism, has undergone so high a differentiation between long and short styled that its long styled individuals behave as if they were female; and short styled individuals as if male. In long-styled individuals, filament, anther, and pollen grains show signs of degeneration, most of the pollen being abortive. On the other hand, in short styled individuals, the filament, anther, and pollen grains have attained remarkable development; the pollen grians are large and fertile. In short-plant the fertilized flowers readily drop off in every stage of their embryo development. This species has completely lost the self-fertile property, which is characteristic of the non-dimorphic Polygonum genus. Although this specsei typically exhibits the physiological characteristics of the non-dimorphic Polygonum genus. Although this specisei typically exhibits the physiological characteristics of dimorphism in controlled pollination, the short-styled individuals bear no seed in nature, thus misleading taxonomists to idenfity the short-styled plant as male. 2) The morphological feature of the flower organ of P. senticosa obviously indicates definite dimorphism. Physiologically, however, no differentiation towards dimorphism was observed, the species still retaining, both in long and short-individuals, the self-fertile property common to the Polygonum genus. Elaborate examinations revealed that regardless of the modes of pollination, both fertiization and seed setting flourish, no differentiation betwen legitimate and illegitimate unions being recognizable. This sort of physiological property has not been observed in the investigations of other heterostylous plants. It is assumed that this species is differentiated structurally into dimorphism, but not yet physiologically. In nature, however, this plant would have more opportunities to be cross-pollinated, i.e., legitimately combined, than self-pollinated because of the development of two forms of flowers. 3) In terms of heterostylism, the F. esculentum just occupies the intermediate position between P. japonica and P. senticosa structurally, ecologically, and physiologically. Doescription of some of the physiological behavior of the plant will suffice to demonstrate the above facts. While P. japonica has completely lost its self-fertile property, P. senticosa still retains it wolly. In F. esculentum 2-6% of self-fertility is the result in illegitimate combination. There occur occasionally hereditary self fertile individuals among some of the F. or 20 min. irradiation plot, when they reach any stage of the same bacterial population. In addition to this increase of total population in the plots with the more dose of UV light irradiation, it seems that the more dose of UV light irradiation is the more shortened the generation time of Azotobacter. Therefore, it is clear that variation of reproductive rate must be, mere or less, due to the genetic effects induced by UV light irradiation. On the other hand, the lag phase or logarithmic growth phase in nonirradiated culture is shortened prominently, and this must be due to the difference in bacterial number of the original inoculm. The generation time of Azotobacter is shortened by exogeneous treatment of nuclei acid derivatives, and the degree is greater in case of DNA derivatives than RNA dervatives. W.H. Price reported that the rate of ribose nucleic acid to protein in Staphylococcus muscae is proportional to the generation time: that is the faster the cell can form ribose nucleic acid, the more rapid its growth. This explains the shortening of generation time by exogeneous RNA derivatives in this work reasonably. On the other hand, it is well known that the desoxyribose nuclic acid content per cell is constant and independent of the generation time. A.D. Laren and W.N. Takahashi reported that the infectious RNA from TMV is 6 times as sensitive to inactivation by UV as it is in the form of intact virus, and that inactivation of infectious TMV involves onlu a local change on RNA chain. But, the effect of exogeneous DNA in this work suggests that irradiated living cell which cotain DNA bring about some change on DNA moleculs as well as RNA molecules. And if the mutagenic effects of UV take into consideration, it is very reasonable. Therefore, it is clear that the variation of the generation time by UV irradiation is, more or less, due to the genetic effects. Therefore, it seems that the shortness of the average lifewpan of Azotobacter by UV irradiation is resulted not only from the influence of the environmental conditions, but also from the variation of genetic factor of the individual.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.1-20
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• 2004

This study focuses on the hydrochemical characteristics in goundwater affected by reclamation at 2000 Sydney Olympic Games site, Sydney, Australia. The Olympic Games site can be divided into three areas, i.e. reclaimed areas; landfill areas and non-infilled areas. In the current work, 'reclaimed areas' were previously estuarine, and were filled with waste materials and are now above present high tide level, whereas 'landfill areas' are areas where deposition of waste materials occurred above sea level. No deposition of waste took place in 'non-infilled areas'. This study was also evaluated by three different types such as deep boreholes, shallow boreholes and standpipes. The hydrochemishy of groundwaters in reclaimed and non-in-filled areas is characterized by Mg- and Ca-enrichment, whereas groundwaters in landfill areas are elevated in K and NO₃. Na, K and Mg are the dominant cations in groundwater from reclaimed areas and Na and K are the dominant cations in groundwater in landfill areas. Na and Mg are the dominant cations in groundwater in deep boreholes, whereas Na and K are the dominant cations in groundwater in shallow boreholes and standpipes. There is no distinct trend in heavy metals with electrical conductivity in the groundwater between the re-claimed, landfill and non-infilled areas. Fe and Mn in landfill areas with respect to reclaimed areas and non-infilled areas show a distinct increase in concentration with declining pH. Mean electrical conductivity values in the deep and shallow boreholes are higher than that of standpipes, but the minimum and maximum value of electrical conductivity in groundwater in standpipes shows remarkably different value, probably due to perched pond. There is no correlation between Cu, Pb, Zn, Cr concentrations in groundwater with pH, from deep boreholes, shallow boreholes and standpipes, except for Fe and Mn, which demonstrate increasing concentrations with declining pH. The results revealed a close association between elevated concentrations in groundwater and the presence of fill materials at the site. Trace metals teachability from re-claimed soils adjacent to estuary plays a significant role in determining their potential environmental risk to surrounding environment.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.833-840
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• 2004

The current study was conducted to analysis the effects of sex and live weight on carcass characteristics using total 773 Hanwoo, and to assess the effects of quality grade on chemico-physical and sensory characteristics in longissimus muscle. Results show that both steer and cow received superior quality grade to bull within the same weight c1ass(P < 0.05). Marbling score, texture, maturity, meat color and fat color were significantly( P< 0.01) affected by sex, whilst only marbling score and maturity were significantly affected by live weight. The ultimate quality grade showed significant relationships with marbling score(r = - $0.81^{**}) meat color (r= 0.21^{**}) fat color(r = 0.10^{**}) and with texture(r = 0.41^{**})$ but that had no such a relationship with maturity. WB-shear force and cooking loss were decreased when carcass grade was increased(P < 0.01), but water-holding capacity was identical between the quality grades. Objective meat color dimensions in lightness, redness and yellowness were increased for higher quality grade(P< 0.01). Meat flavor, juiciness and tenderness received higher scores for higher quality grade(P< 0.01). Intramuscular fat content had significantly relationships with WB-shear force(r = 0.$56^*), water-holding capacity(r = 0.18^{**}), juiciness(r = 0.46^{**}), tenderness(r= 0.49^{**})$, and flavor intensity(r = 0.$34^*$). In addition, a higher WB-shear force was related to a lower flavor, tenderness and juiciness scores.