• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.85-92
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• 2008

National Oceanographic Research Institute is carrying out an oceanographic survey for the entire sea areas around Korean Peninsula annually starting with the East Sea from 1996 by establishing a national oceanographic basic map survey plan for the sea areas under the jurisdiction of Korea, so this paper used the oceanographic geomagnetism data measured at the southern area of the Yellow Sea using 'Hae Yang 2000' in 1999, aiming at clarifying the cause of geomagnetic abnormality zone during the course of treating and analyzing the geomagnetic data. For treatment of magnetic data, we obtained electromagnetic force values and geomagnetic abnormality values around the investigated sea area through a process of searching and removal of bad data, correction of sensor positions, correction of magnetic field effects around the hull, correction of diurnal variation, normal correction, correction of cross point errors, etc. The electromagnetic force distribution around the investigated sea area was $49000\;{\sim}\;51600\;nT$, which is judged to be within the normal electromagnetic force intensity distribution range around the Yellow Sea. The isodynamic lines are distributed in Northeast-Southwest direction, and electromagnetic force values are increasing toward the northwest. The result of comparing the magnetic abnormality around the sea area among $124^{\circ}$ 49' 48" E, $35^{\circ}$ 10' 48" N $\sim$ $125^{\circ}$ 7' 48" E, and $35^{\circ}$ 33' 00" N sections with the elastic wave cross section and the result of modeling coincide well with the underground geological structure clarified from the existing elastic wave survey cross section. Therefore, it is judged that the distribution of magnetic force abnormality generally shows the effect pursuant to the distribution of the sedimentary basins in the Tertiary period and the bedrocks in the Cretaceous period which are well developed in the bottom of the sea.

• Journal of Korean Philosophical Society
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• v.137
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• pp.109-130
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• 2016

Plato learned of teleology from his teacher Socrates and expanded it to its application in cosmology. His cosmological work Timaeus was the final edition of teleological view. The motive that Demiurge created the cosmos was in resemblance of his goodness. He then modeled the idea of the Good imposing limit to the Forms of Good in a material world. In this sense, Demiurge was an excellent creator and created the Good cosmos. The cosmic body was made from four elements (water, fire, air, earth) and the cosmic soul entered the cosmic body and the cosmic intelligence (nous) entered the cosmic soul. According to these steps, this cosmos was created and named a living god. In conclusion, Plato asserts that this cosmos was created by God's teleological project, and resembles the goodness of a god. When man followed the order and balance in the cosmos, the good of the individual and the state would be accomplished.

• Journal of Soil and Groundwater Environment
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• v.28 no.spc
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• pp.40-54
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• 2023

산업혁명 이후 화석연료의 광범위한 사용, 삼림 벌채, 토지사용의 변화 등과 같은 인위적 활동은 대기 중 온실가스(GHGs, greenhouse gases) 농도를 지속적으로 증가시켜 지구의 기후위기를 유발하였다. 우리나라의 경우 최근 30년 사이 평균 온도가 1.4℃ 상승하였으며, 국제사회의 일원으로 책임을 다하기 위해 2016년 11월 3일 파리협정을 비준하였다. 이에 파리협정의 목표인 산업화 이전 대비 지구 평균온도 상승을 2℃ 아래, 가능한 1.5℃ 아래로 억제하기 위해 2050년까지 CO₂ 순배출량을 0으로 만들어야 하며, 이를 위해 다양한 정책 마련과 함께 경제 및 사회 전반에 걸쳐 많은 노력이 경주되고 있는 실정이다. 탄소중립을 달성하기 위해서는 첫 번째로 GHGs 배출을 줄이고, 두번째로 대기에서 CO₂ 포집을 촉진하기 위해 현재 가동되는 다양한 산업분야의 생산 시스템을 개혁하는 것이 가장 중요한 과제로 고려되고 있다. 그동안 지하수토양 관련 연구분야에서는 지속가능성(sustainability), 복원성(resilience), 녹색성장(green growth) 등과 같은 사회적 요구에 부응하여, 녹색정화(green remediation), 자연 저감(natural attenuation), 탄소포집저장(carbon capture and sequestration), 지열발전등의 기술이 초기단계로 개발이 되고 연구가 되어 왔다. 이러한 기존 연구들은 탄소중립2050의 달성을 위해 고도화되어야하며, 추가적으로 자연 및 인위기원 탄소배출 연구, 토양의 역할을 고려한 저탄소 토지이용 기술, 광물탄산화 등의 연구 및 기술개발이 필요하다고 판단된다. 본 논문에서는 탄소중립2050의 간단한 내용과 함께, 이를 달성하기 위한 지하수토양 분야의 혁신기술 및 선도연구를 소개하였다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.273-279
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• 2007

In order to estimate the sedimentation rates of continental shelf and slope of Ulleung Basin in the Southwestern East Sea, $^{210}Pb,\;^{226}Ra\;and\;^{137}Cs$ were simultaneously measured by a well-type high purity germanium(HPGe) gamma detector. $^{137}Cs$ was used to determine whether the sediment were affected by bioturbation or not, and to judge the accuracy of estimated sedimentation rates. The estimated sedimentation rates decreased exponentially from slope to basin - 0.6 cm/yr in the continental shelf, $0.3{\sim}0.4$ cm/yr in the slope, and below 0.2 cm/yr in the margin of Ulleung basin. From our and other research results, we suggest followings about sediment transport of the study area. The sediment particles were transported by coastal current from south to north through the Korea Straight. And much of them were accumulated in the shelf area. And then, the rest of sediment particles were deposited in the lower slope and the southwest margin of the basin. Also the excess $^{210}Pb$ profiles indicate that the depositional processes in the study area may have been very complicate.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.315-327
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• 2007

This study investigated temporal and spatial variation of Pb and stable Pb isotopes accumulated in Ulleung Basin core sediments (4) using MC ICP/MS in order to identify the sources of anthropogenic Pb in the East/Japan Sea. Leached (1M HCl) Pb concentration and isotope ratios ($^{207}Pb/^{206}Pb\;and\;^{208}Pb/^{206}Pb$) were nearly constant during 300 yrs past than 1930, but increased up to twice in concentration and as much as 3.41% (1.70%) after 2000. On the other hand, residual Pb concentrations were nearly constant for past 400 yrs. The accumulation rates of anthropogenic Pb in the basin area were in the range of $3.1-3.5mg/m^2/yr$, which were similar levels to total atmospheric Pb deposition fluxes from 1990s to the present. In the slope area, more increase of anthropogenic Pb accumulation than the levels expected from mass accumulation rate could be found after the middle of 1990s. From the detailed evaluation for the temporal and spatial variation of accumulation rate and isotope ratios of anthropogenic Pb, we proposed probable sources and pathways of anthropogenic Pb. Pb emmision by coal burning from the China and Korea initiated the accumulation of anthropogenic Pb in the sediments of East/Japan Sea from 1930s. The accumulation of Pb increased by the addition of anti-nocking agents from both countries untill the beginning of 1990s, but from the middle of 1990s to the present, the phase-out of gasoline additives and the rapid increase of coal burning from the China maintained the atmospheric Pb levels in the Ulleung basin nearly similar to before. However, the local sources within this basin might take an important role in the rapid increase of anthropogenic Pb accumulation in slope areas from the middle of 1990s.

• The Journal of Engineering Geology
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• v.14 no.4 s.41
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• pp.361-369
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• 2004

The authors designed a new technique to measure dielectric constant of a soil media by Frequency Domain Reflectometry (FDR) system and its measurement sensor probe with different length such as 7m, 10cm and 15cm for estimating the variations of dielectric constant. Measurement of dielectric constant of soil material is possible to measure an interference wave generated by between incidence wave and reflection wave which are detected to electro-magnetic wave through the directional coupler at the high frequency range,0.1 to 1.7GHz, by FDR system. The obtained experimental results verified that the technique is very promising for non-destructive and continuous soil volumetric water content measurement monitoring in a laboratory. The relationship between the soil volumetric water content and the dielectric constant of soil media (standard sand) was expressed by a single regression ewe independent of soil texture at a small experimental error. Also the derived regression curve coincided well with that obtained by Topp curve.

• Journal of Ginseng Research
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• v.30 no.4
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• pp.206-211
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• 2006

To investigate mycorrhizal infection by arbuscular mycorrhizal fungi(AMF), samples of fine lateral roots were taken from the wild ginseng(Panax ginseng C.A. Meyer) naturally growing at various locations in Korea. Mycorrhiazal infections were studied by cleaning the root samples and staining fungal hyphae with frypan blue. Wild ginsengs for this study were graded by an appraisal committee consisting of 12 experts of Korea Mountain Ginseng Association. Following five quality groups were recognized: Heaven group(pure natural), Earth group (from seeding of wild ginseng), Man group(from seeding or seedlings of wild ginseng with slight environmental modification), unmarketable, and imported wild ginseng. Morphology of AMF was typical Paris-type which shows intracellular hyphal coils with rare vesicles and lack of arbuscules. Average infection rate of individual wild ginsengs was 58.3% and showed no differences among five quality groups. When portions of fine roots were quantified for mycorrhizal infection, 18.7% of the total length of the primary and secondary roots were infected by AMF. Wild ginsengs from Gyeonggi Province(84.2%), and from mountains lower than 1,200 meters above sea level(about 70%) showed higher infection rate, while the ginseng from Gyeongbuk Province(27.8%) had lower rate. Wild ginsengs at older age showed lower infection rates.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.145-152
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• 2006

Industry development caused numerical and quantitative increase of noxious chemical substances that contain risk assessment in water resources. For use of efficient water resources a pre-treatment of contaminant source which is flowed in water resources is recognized in essential process. Therefore, the discharged water quality from discharged company began to control contaminant by total amount of pollutant in domestic. However, to estimate closely chemical substances it is not proved up to now, monitoring is very important. This study achieved a monitoring of micro noxious chemical substance by fiber and chemistry industrial wastewater inflow to examine risk assessment of the water system of Nakdong river. Chloroform was measured highest among volatile organic compounds (VOCs) that the results of water quality of influent and effluent are detected from 7 companies of study area. The other side, because measured value of detected chloroform is indefinite detection level in the same company, it is difficulty in management of water quality. However it may not be much effects of the water system of Nakdong river because these company's effluent is high treatment efficiency of chloroform (more than 88%) in sewage treatment plant. On the other hand, in the investigated results for the European Union specified priority substance that is detected to relationship influent and effluent from fiber/chemistry associated industries, these substances were not detected and domestic data was hardly referred. Therefore, data construction of continuous monitoring about this water quality may have to be achieved certainly to utilize as country policy.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.125-134
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• 2006

In order to establish the in-situ application of the artificial storage and recovery (ASR) technology which is used the property of the aquifer storage of groundwater. We carried out to the in-situ experiments such as borehole TV logging, pumping test and artificial hydraulic fracturing in volcanic island, Ulleungdo. In-situ experiments were conducted to divide the before- and after-hydraulic fracturing. Pumping test was achieved to confirm the two fracture zones, GL-13m and GL-21m, which are determined by the borehole TV logging. From the results of the before- and after-pumping tests, the hydraulic connectivity was confirmed to locate at GL-13m in the residual deposit zone of pumice media as alluvium. However, in the bedrock tone at GL-21m the hydraulic connectivity could be considered to faulty. Consequently, in this study area the artificial recharge has a little unsatisfied to geo-structural condition and desired to more detail investigation works.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.135-143
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• 2006

This study presents the results of a series of laboratory scale slope failure experiments aimed at clarifying the process and the condition leading to the initiation of rainfall-induced slope failures. For the evaluation of hydrologic response of the model slopes in relation the process of failure initiation, measurements were focused on the changes in volumetric water content during the initiation process. The process leading to failure initiation commences by the development of a seepage face. It appears reasonable to conclude that slope failures are a consequence of the instability of seepage area formed at the slope surface during rainfall period. Therefore, this demonstrates the importance of monitoring the development seepage area for useful prediction about the timing of a particular failure event. The hydrologic response of soil slopes leading to failure initiation is characterized by three phases (phase I, II and III) of significant increase in volumetric water content in association with the ingress of wetting front and the rise of groundwater level within the slope. The period of phase III increase in volumetric water content can be used to initiate advance warning towards a failure initiation event. Therefore, for the concept outlined above, direct and continuous monitoring of the change in volumetric water content is likely to provide the possibility for the development of a reliable and effective means of predicting the occurrence of rainfall-induced slope failures.