• Tunnel and Underground Space
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• v.16 no.2 s.61
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• pp.109-134
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• 2006

Rocks undergo weathering processes influenced by changing in pressure-temperature condition, atmosphere, underground water, and rainfall. The weathering processes change physical and chemical characteristics of the rocks. Once the rocks are weathered, the characteristics of them are changed and, because of the changing, several disadvantages such as rock slope failures and underground water spouts are can occur. Before we cut a large rock slope, therefore, we must analyze current weathering conditions of rocks and predict weathering processes in the future. Through the results of such analyses, we can judge reinforcement works. In order to comply with such requests, chemical weathering sensitivity analysis which was analyzed from chemical weathering velocities and other characteristics of rocks has been applied in several prior construction works in Korea. But, It is defective to use directly in engineering fields because it was developed for soils(not rocks), it has too mny factors must be considered and the relationships between the factors are not clear, and it is hard to explain the weathering processes in engineering time range. Besides above, because it has been used for isotropic rocks, this method is hard to apply to anisotropic rocks such as sedimentary rocks. Acceding to studies from morphologists (e.g. Oguchi et al., 1994; Sunamura, 1996; Norwick and Dexter, 2002), time dependent strength reduction influenced by weathering shows a negative exponential function form. Appling this relation, one can synthesize the factors which influence the weathering processes to the strength reduction, and get meaningful estimates in engineering viewpoint. We suggest this weathering sensitivity characterization method as a technique that can explain time dependent weathering sensitivity characteristics through strength changes and can directly applied the rock slope design.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.15-22
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• 2009

Adequate environment conditions with growth stage of potato were decided in a photoautotrophic micropropagation system using models. Total 20 day-period of growth were divided into three growth periods such as 6 (stage 1), 7(stage 2), and 7(stage 3) days. At the 1st stage, no significant differences were observed in the growth of potato plantlets at various photosynthetic photon flux density (PPFD) and $CO_2$ conditions. Considering damaged leaves, $80\;mmol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and ambient $CO_2$ level were adequate in this stage. At the 2nd stage, significant differences were partly observed in several growth characteristics including dry weight. Based on the dry matter model, over $240\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD was too high to cultivate potato plantlets at this stage due to the occurrence of damaged leaves. Considering both plant growth and energy efficiency, $160\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and $700\;mol{\cdot}mol^{-1}\;CO_2$ were selected for the adequate combination. At the 3rd stage, the biomass accumulation was significantly induced in potato plantlets under higher levels of PPFD and $CO_2$ concentration as suggested by increased fresh and dry weights. However, we could not find the saturated point with regard to dry matter due to continuous increase of dry mater even under maximum PPFD ($320\;mmol{\cdot}m^{-2}{\cdot}s^{-1})$. Thus, $320\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and $1800\;mol{\cdot}mol^{-1}\;CO_2$ were considered as the best choice at final stage in this study. In conclusion, even though the growth period of micropropagated potato plantlets was quite a short, favorable environmental conditions required at each growth stage were different. This technique could improve the growth of micropropagated plantlets compared to the conventional micropropagation and apply to other agriculturally important crops as well as potato in the future.

• Atmosphere
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• v.23 no.3
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• pp.293-305
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• 2013

Nonhydrostatic effects on convectively forced mesoscale flows in two dimensions are numerically investigated using a nondimensional model. An elevated heating that represents convective heating due to deep cumulus convection is specified in a uniform basic flow with constant stability, and numerical experiments are performed with different values of the nonlinearity factor and nonhydrostaticity factor. The simulation result in a linear system is first compared to the analytic solution. The simulated vertical velocity field is very similar to the analytic one, confirming the high accuracy of nondimensional model's solutions. When the nonhydrostaticity factor is small, alternating regions of upward and downward motion above the heating top appear. On the other hand, when the nonhydrostaticity factor is relatively large, alternating updraft and downdraft cells appear downwind of the main updraft region. These features according to the nonhydrostaticity factor appear in both linear and nonlinear flow systems. The location of the maximum vertical velocity in the main updraft region differs depending on the degrees of nonlinearity and nonhydrostaticity. Using the Taylor-Goldstein equation in a linear, steady-state, invscid system, it is analyzed that evanescent waves exist for a given nonhydrostaticity factor. The critical wavelength of an evanescent wave is given by ${\lambda}_c=2{\pi}{\beta}$, where ${\beta}$ is the nonhydrostaticity factor. Waves whose wavelengths are smaller than the critical wavelength become evanescent. The alternating updraft and downdraft cells are formed by the superposition of evanescent waves and horizontally propagating parts of propagating waves. Simulation results show that the horizontal length of the updraft and downdraft cells is the half of the critical wavelength (${\pi}{\beta}$) in a linear flow system and larger than ${\pi}{\beta}$ in a weakly nonlinear flow system.

• Investigative Magnetic Resonance Imaging
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• v.17 no.4
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• pp.294-307
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• 2013

Purpose : To investigate the correlations between Seoul Neuropsychological Screening Battery (SNSB) scores and the gray matter volumes (GMV) in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) and cognitively normal (CN) elderly subjects with correcting the genotypes. Materials and Methods: Total 75 subjects were enrolled with 25 subjects for each group. The apolipoprotein E (APOE) epsilon genotypes, SNSB scores, and the 3D T1-weighted images were obtained from all subjects. Correlations between SNSB scores and GMV were investigated with the multiple regression method for each subject group using both voxel-based and region-of-interest-based analyses with covariates of age, gender, and the genotype. Results: In the AD group, Rey Complex Figure Test (RCFT) delayed recall scores were positively correlated with GMV. In the MCI group, Seoul Verbal Learning Test (SVLT) scores were positively correlated with GMV. In the CN group, GMV negatively correlated with Boston Naming Test (K-BNT) scores and Mini-Mental State Examimation (K-MMSE) scores, but positively correlated with RCFT scores. Conclusion: When we used covariates of age, gender, and the genotype, we found statistically significant correlations between some SNSB scores and GMV at some brain regions. It may be necessary to further investigate a longitudinal study to understand the correlation.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.510-514
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• 2007

This study was carried on cool and RT(room temperature) storage of unhulled rice. In RT storage of an analysis of coefficient relation, high significant positive coefficients were observed in toyo index and breakdown, setback and protein content. high significant negative coefficients were showed setback and breakdown, breakdown and protein content. In cool storage of an analysis of coefficient relation, high significant positive coefficients were observed in toyo index and amylose content and gelatinization start temperature and protein content and high significant negative coefficients were showed toyo index and whiteness, toyo index and gelatinization start temperature, gelatinization start temperature and amylose content. In RT storage of a path coefficient analysis, a highest positive direct influence was observed in amylose content and a highest negative direct influence was protein content. Positive indirect influence was high revealed breakdown and protein content and negative indirect influence was gelatinization start temperature and Mg/K ratio. In cool storage of a path coefficient analysis, a highest positive direct influence was whiteness and a highest positive indirect influence was gelatinization start temperature. Positive indirect influence was high revealed gelatinization start temperature and amylose content, negative indirect influence was whiteness and gelatinization start temperature. In RT storage of Multiple regression equation of Toyo index based on physicochemical properties of unhulled rice, a highest coefficient of determination was revealed among five facters of whiteness, protein content, Mg/K ratio, amylose content and gelatinization start temperature. In cool storage of Multiple regression equation of toyo index based on physicochemical properties of unhulled rice, highest coefficient of determination was revealed among five facters of moisture content, amylose content, gelatinization start temperature, breakdown and setback.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1062-1068
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• 1997

From August 1989 to January 1996, a total of 105 cases of bidirectional Glean operations have been done as the interim stage for the patien s with some risk of univentricular correction at Sejong General Hospital. From December 1992, we started the conversion to Fontal operations for them, and 42 cases underwent Fontal-stage operation till February 1996. Their diagnoses were univentricular heart in 19(right ventricular type : 14), tricuspid atresia 11, double outlet of right ventricle 9, and others in 3 cases. The median age of bidirectional Glerln-stage operation was 12.5 months(range 2 months to 8 years) and Fontan-stage operation was at 59.6 months of median age(range 1 year 5 months to ,9 year 7 months). The mean waiting interval between the two operations was 33.88 $\pm$ 17.85 months with a range of 10 months to 6 years 3 months. During the waiting periods, 18 patients developed significant systemic-pulmonary collaterals andfor systemic verso-veno collateral channels. There were 5 hospital deaths after operations due to low cardiac output in 4 and sepsis in one. Most of the Fontal-stage operations were done by the late al tunneling with Core-Tex tube graft patch and fenestrated with the size of 2.5 ~6 mm. All the patients were followed-up(7 months to 4 years 2 months, mean 21.97$\pm$10.82 months) and there were 5 late deaths(postoperatively 6 months to 2 years) due to thromboembolism in 1, after heart transplantation 1, plastic bronchitis 1, protein loosing enteropathy 1, and pneumonia in 1. Dividing the patients by the waiting interval of 2 years, the early correction to Fontal group (N=16) showed the better results(hospital mortality 1116, late mortality 1116, significant collateral development 2/16) compared to the other group(N=26) (4/26, 4/26, 16/26). In conclusion, after the bidirectional Glean-stage operation successfully got rid of the previous risk factors, we recommand to do the Fontan-stage operation no later than 2 years of interval.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.96-115
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• 2017

Understanding effects of thermal pollution and acidification has long been a concern of aquatic ecologists, but it remains largely unknown in Korea. This study was performed to elucidate the effects of thermal wastewater effluent (TWE) and acid rain on water quality and attached algae in a small mountain stream, the Buso Stream, a tributary located in the Hantan River basin. A total of five study sites were selected in the upstream area including the inflowing point of hot-spring wastewater (HSW), one upstream site (BSU), and three sites below thermal effluent merged into the stream (1 m, 10 m and 300 m for BSD1, BSD2, and BSD3, respectively). Field surveys and laboratory analyses were carried out every month from December 2015 to September 2016. Water temperature ranged $1.7{\sim}28.8^{\circ}C$ with a mean of $15.0^{\circ}C$ among all sites. Due to the effect of thermal effluent, water temperature at HSW site was sustained at high level during the study period from $17.5^{\circ}C$ (January) to $28.8^{\circ}C$ (September) with a mean of $24.2{\pm}3.7^{\circ}C$, which was significantly higher than other sites. Thermal wastewater effluent also brought in high concentration of nutrients(N, P). The effect of TWE was particularly apparent during dry season and low temperature period (December~March). Temperature effect of TWE did not last toward downstream, while nutrient effect seemed to maintain in longer distance. pH ranged 5.1~8.4 with a mean of 6.9 among all sites during the study period. The pH decrease was attributed to seasonal acid rain and snow fall, and their effects was identified by acidophilic diatoms dominated mainly by Eunotia pectinalis and Tabellaria flocculosa during March and August. These findings indicated that water quality and periphyton assemblages in the upstream region of Buso Stream were affected by thermal pollution, eutrophication, and acidification, and their confounding effects were seasonally variable.

• Korean Journal of Plant Resources
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• v.22 no.1
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• pp.49-70
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• 2009

Floral study on the vegetation of 8 mountains including Taehwa-san, Mugab-san, Haehyeob-san, Guksa-bong, Gwanggyo-san, Samseong-san, Suri-san, and 200m peak neighboring to Mulwang lake was carried out from April to October, 2007. They belong to the middle part of Gyeonggi Province, and located between Lat. $37^{\circ}$13' 31.19" ${\sim}37^{\circ}$33' 3.48", Long. $26^{\circ}$43' 04.1" ${\sim}127^{\circ}$26' 28.38". Vascular plants collected in these areas were total 447 taxa composed of 386 species, 5 subspecies, 46 varieties and 10 forms of 262 genera under 92 families. The area from which the most plentiful plants were found was Mt. Gwanggyo-san. The areas with comparatively excellent vegetation are easy slopes nearby valleys in Mt. Gwanggyo-san, Mt. Suri-san and Mt. Haehyeob-san. Forests of the examined areas are generally mixed of Pinus densiflora and Quercus plants, but herbaceous plants covering soil are becoming nearly extinct by air and soil pollutions except some sites. Families with abundant species are Compositae, Rosaceae, Liliaceae and Graminae, etc. Endemic plants found in these areas are 8 taxa of Clematis brachyura, Euonymus trapococcus, Viola seoulensis, Ajuga spectabilis, Scutellaria insignis, Weigela subsessilis, Aster koraiensis, Aconitum chiisanense and rare and endangered plants are 7 taxa of Arisaema heterophyllum, Iris odaesanensis, Eranthis stellata., Aconitum chiisanense, Prunus yedoensis (cultivar), Viola albida, and Syringa wolfi. As to useful plants, 192 taxa for the edible, 132 taxa for the medicinal, 130 taxa for the ornamental and 11 taxa for the staining were classified respectively. Among 17 taxa of specially designated plants, 5th degree plants are 2 taxa of Iris odaesanensis and Prunus yedoensis (cultivar), 4th degree plants are 2 taxa of Symplocarpus renifolius and Syringa wolfi, 3rd degree plants are 13 taxa of Dryopteris gymnophylla, Juniperus chinensis, Betula chinensis, Betula davurica, Diarrhena fauriei, Aconitum longecassidatum, Eranthis stellata, Spiraea salicifolia, Acer palmatum, Vaccinium koreanum, Scutellaria insignis, Weigela florida and Adoxa moschatellina.

• 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.

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.1
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• pp.153-194
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• 2009

The resources of outer space are for the common exploitation of mankind, and it is a common responsibility of mankind to protect the outer space environment. With the rapid development of space science and technology, and especially with the busy space activities of some major space powers, environmental contamination or space debris is steadily increasing in quantity and has brought grave potential threats and actual damage to the outer space environment and human activities in space. Especially We must mitigate and seek out a solution to remove space debris which poses a threat directly to man's exploitation and use of outer space activities in the Low Earth Orbit (LEO) and in the Geostationary Orbit (GEO), through international cooperation and agreement in the fields of space science, economics, politics and law, in order to safeguard the life and property of mankind and protect the earth's environment. While the issue of space debris has been the subject of scientific study and discussion for some time now, it has yet to be fully addressed within the context of an international legal framework. During the earlier stages of the space age, which began in the late 1950s, the focus of international lawmakers and diplomats was the establishment of basic rules which sought to define the legal nature of outer space and set out the parameters for space activities and the nature and scope of activities carried out in outer space were quite limited. Consequently, environmental issues and the risks that might arise from the generation of space debris did not receive priority attention within the context of the development international space law. In recent years, however, the world has seen dramatic advances in technology and increases in the type and number of space-related activities which are being carried out. In addition, the number of actors in this field has exploded from two highly developed States to a vast array of different States, intergovernmental and nongovernmental organizations, including private industry. Therefore, the number of artificial objects in the near-Earth space is continually increasing. As has been previously mentioned, COPUOS was the entity that created the existing five treaties, and five sets of legal Principles, which form the core of space law, and COPUOS is clearly the most appropriate entity to oversee the creation of this regulatory body for the outer space environmental problem. This idea has been proposed by various States and also at the ILA Conference in Buenos Aires. The ILA Conference in Buenos Aires produced an extensive proposal for such a regulatory regime, dealing with space debris issues in legal terms This article seeks to discuss the status of international law as it relates to outer space environmental problem and space debris and indicate a course of action which might be taken by the international community to develop a legal framework which can adequately cope with the complexity of issues that have recently been recognized. In Section Ⅱ,Ⅲ and IV of this article discuss the current status of international space law, and the extent to which some of the issues raised by earth and space environment are accounted for within the existing United Nations multilateral treaties. Section V and VI discuss the scope and nature of space debris issues as they emerged from the recent multi-year study carried out by the ILA, Scientific and Technical Subcommittee, Legal Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space ("COPUOS") as a prelude to the matters that will require the attention of international lawmakers in the future. Finally, analyzes the difficulties inherent in the future regulation and control of space debris and the activities to protect the earth's environment. and indicates a possible course of action which could well provide, at the least, a partial solution to this complex challenge.