• Title/Summary/Keyword: 해양지질

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Change Detection of Land Cover Environment using Fuzzy Logic Operation : A Case Study of Anmyeon-do (퍼지논리연산을 이용한 토지피복환경 변화분석: 안면도 사례연구)

  • 장동호;지광훈;이현영
    • Korean Journal of Remote Sensing
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    • v.18 no.6
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    • pp.305-317
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    • 2002
  • The purpose of this study is to analyze the land cover environmental changes in the Anmyeon-do. Especially, it centers on the changes in the land cover environment through methods of GIS and remote sensing. The land cover environmental change areas were detected from remote sensing data, and geographic data sets related to land cover environment change were built as a spatial database in GIS. Fuzzy logic was applied for data representation and integration of thematic maps. In the natural, social, and economic environment variables, the altitude, population density, and the national land use planning showed higher fuzzy membership values, respectively. After integrating all thematic maps using fuzzy logic operation, it is possible to predict the change quantitatively. In the study area, a region where land cover change will be likely to occur is the one on a plain near the shoreline. In particular, the hills of less than 5% slope and less than 15m altitude, adjacent to the ocean, were quite vulnerable to the aggravation of coastal environment on account of current, large-scale development. In conclusions, it is expected that the generalized scheme used in this study is regarded as one of effective methodologies for land cover environmental change detection from geographic data.

Study of Groundwater Recharge Rate Change by Using Groundwater Level and GRACE Data in Korea (지하수위와 GRACE 자료를 이용한 국내 지하수 함양량 변화 연구)

  • Jeon, Hang-Tak;Hamm, Se-Yeong;Jo, Young-Heon;Kim, Jinsoo;Park, Soyoung;Cheong, Jae-Yeol
    • The Journal of Engineering Geology
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    • v.29 no.3
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    • pp.265-277
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    • 2019
  • Changes in the amount, intensity, frequency, and type of precipitation, in conjunction with global warming and climate change, critically impact groundwater recharge and associated groundwater level fluctuations. Monthly gravity levels by the Gravity Recovery and Climate Experiment (GRACE) are acquired to monitor total water storage changes at regional and global scales. However, there are inherent difficulties in quantitatively relating the GRACE observations to groundwater level data due to the difficulties in spatially representing groundwater levels. Here three local interpolation methods (kriging, inverse distance weighted, and natural neighbor) were implemented to estimate the areal distribution of groundwater recharge changes in South Korea during the 2002-2016 period. The interpolated monthly groundwater recharge changes are compared with the GRACE-derived groundwater storage changes. There is a weak decrease in the groundwater recharge changes over time in both the GRACE observations and groundwater measurements, with the rate of groundwater recharge change exhibiting mean and median values of -0.01 and -0.02 cm/month, respectively.

Eruptive History of the Ulleungdo-Dokdo Volcanic Group, the East Sea: a Multi-Scale Approach (동해 울릉도-독도 화산그룹 분화사 다중스케일 연구)

  • Kim, Gi-Bom;Lee, Jae-Hyuk;Ahn, Ho-Jun;Je, Yoon-Hee
    • Journal of the Korean earth science society
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    • v.43 no.1
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    • pp.140-150
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    • 2022
  • This paper focuses on introducing the concept of the multi-scale study on the Ulleungdo-Dokdo Volcanic Group in the East Sea and recent new findings from it. Multi-channel seismic reflection data reveals that the major volcanic activities of the Ulleungdo-Dokdo Volcanic Group took place between 5 and 2.5 Ma, which were propagated from Isabu Tablemount on the eastern end to the Ulleung Island on the western end. The terrestrial Ulleung Island was built via 5 stages, which eventually formed a 3 km-wide caldera, named Nari Caldera, and a volcanic dome, named Albong, within the caldera. The Albong and the unit N-1, the earliest phreatomagmatic explosive phase of the Albong volcano, were generated from a new magma injected into the existing phonolitic body. The generally trachyandesitic bulk rock composition of the pumice in unit N-1 and Albong is attributed to the contamination of the new magma by mafic cumulates at the base of the existing phonolitic chamber. The lines of evidence of a new magma injection point toward that Ulleung Island is an active volcano with a live subvolcanic magma plumbing system.

Shallow water geoacoustic inversion and matched field processing using narrow band signals (협대역 신호를 이용한 천해환경 지음향 역산 및 정합장처리)

  • Kim Kyungseop;Park Cheolsoo;Seong Woojae
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.385-388
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    • 2004
  • 본 논문에서는 천해 해양환경에서 이동 음원과 수직선배열을 이용한 실 해상 실험 자료를 이용하여 지음향 역산 및 정합장처리를 수행하였다. 협대역 신호를 이용하여 음원의 이동에 따른 전달손실을 계산하였고, 이를 음파전달모델을 이용한 결과와 비교하는 방식으로 역산의 목적함수를 구성함으로써 해저면 지음향 인자들의 평균적인 값을 역산할 수 있었다. 역산 결과로 얻은 지음향 인자들을 사용하여 정합장처리를 통해 음원의 이동경로를 추적함으로써 역산 결과의 타당성을 검증하였고, 이를 기존 지질 자료를 이용한 정합장처리 결과와 비교하였다.

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액젓의 품질지표들의 상관성 분석

  • 최영준;임영선;심길보;김태진;조영제
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.05a
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    • pp.110-111
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    • 2000
  • 액젓의 발효 과정에서 단백질 화합물은 효소 및 미생물의 작용에 의하여 분해되어 맛에 영향을 미치는 유리아미노산 및 저분자 질소화합물 혹은 부패 지표 활용 가능한trimethylamine, ammonia 및 dimethylamine까지 분해되고(Beddow, 1985), 핵산 관련물질은 uric acid까지, 지질은 분해되어 주로 액젓의 냄새에 관여하는 휘발성 성분을 생성한다(Jay, 1966; Nozawa et al., 1979). 액젓 품질에 영향을 미치는 인자는 크게 어종, 염의 형태, 시료어와 염의 혼합비, minor ingredient, 발효 조건 등으로 분류할 있으며, 이 중 가장 큰 비중을 차지하는 원료 물질은 어육과 염으로서 어육은 발효 중 효소 및 미생물 작용의 기질로 제공되고, 염은 발효 중 미생물의 형태나 병원성 미생물의 생성을 억제한다. (중략)

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Calcium-alginate gel을 이용한 DHA유의 캡슐화

  • Yoon, Young-Soo;Kwak, Ki-Seok;Lee, Ju-Hang;Cho, Sang-Won;Lee, Won-Dong;Jeon, Byung-Jun;Lee, Sung;Ji, Chung-Il;Kim, Sang-Ho;Lee, Yang-Bong;Kim, Sun-Bong
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.10a
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    • pp.169-170
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    • 2001
  • 등푸른 생선 등에 많은 eicosapentaenoic acid(EPA, $C_{20-5}$ n-3), docosahexaenoic acid(DHA, $C_{22-6}$ n-3)등의 n-3계 지방산은 순환기 계통 질환의 위험인자를 제거해 주거나 혈청내 지질 구성이나 혈소판응집 기능에 변화를 주어 동맥경화증에 유익한 효과를 나타낸다고 알려져 있다. 특히 DHA는 망막 및 두뇌 인지질의 구성성분으로 실험동물의 학습능을 비롯한 뇌기능 향상에 기여한다고 한다. (중략)략)략)

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Sun Grid Engine-based Satellite Image Processing System (Sun Grid Engine 기반 위성영상 처리 시스템)

  • Choi, Yun-soo;Lee, Min-ho;Lee, Sang-hwan
    • Proceedings of the Korea Information Processing Society Conference
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    • 2013.05a
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    • pp.61-63
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    • 2013
  • 환경, 해양, 지질자원, 기상 기후 등 다양한 분야에서 연구목적으로 인공위성에 의해 관측된 위성영상을 활용하고 있다. 인공위성으로부터 수신된 영상데이터는 많은 왜곡을 포함하고 있으므로, 이를 이용하여 신뢰할 수 있는 분석을 하기 위해서는 영상데이터에 대한 보정 작업이 선행되어야 한다. 하지만 대부분의 전처리 작업이 단일노드/단일코어를 이용하고 있기 때문에 많은 연구자들이 불편함을 가지고 있다. 본 논문은 단일노드/단일코어 상에서 수행되는 위성영상 처리 방식을 다중노드/다중코어를 이용하는 분산 처리 방안을 제안한다. 7개의 작업 실행 노드를 이용하여 실험한 결과에서, 분산 기반의 처리 성능이 단일노드/단일코어에서 수행된 처리 성능보다 최고 560.65% 향상되었음을 보여주었다.

Two-dimensional Inversion of Sea-effect-corrected Magnetotelluric (MT) Data in Jeju Island (해양효과가 보정된 제주도 자기지전류 탐사 자료의 2차원 역산)

  • Yang, Jun-Mo;Lee, Heui-Soon;Lee, Choon-Ki;Park, Gye-Soon
    • Journal of the Korean earth science society
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    • v.32 no.6
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    • pp.602-612
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    • 2011
  • Jeju Island, a volcanic island located in South Korea, has been one of the main targets of geophysical and/or geological studies because of its tectonic importance related to the volcanism and tectonic link to the southern part of the Korean Peninsula. Recently, as a number of broad-band magnetotelluric (MT) measurements were made, we have examined the deep part of the island. In such an insular setting, it is not easy to properly recover the deep structures such as the lower crust and the upper crust using MT data, because their low-frequency components are strongly affected by the surrounding sea of the island. In this study, we apply the sea-effect correction to the existing MT data collected at a total of 102 sites in Jeju Island. The sea-effect correction makes remarkable changes in the observed MT data at frequencies below 1 Hz, clearly indicating the existence of a conductive lower crust. The 2-D inversion results for both Jeju Southern Line (JSL) and Jeju Northern Line (JNL) show that the transition zone separating the resistive upper crust and conductive lower crust exists at a depth of 20 km on average.

Magnetic anomaly in the southern part of the Yellow Sea (서해남부해역의 지자기 이상대 해석)

  • Kim, Sung-Bae;Choi, Sung-Ho;Suh, Man-Cheol
    • 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.

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Characteristics for Progressive Collapse Behavior and Ultimate Strength of Very Large Marine Structure (초대형 해상구조물의 붕괴거동 및 최종강도 특성)

  • Park, Joo-Shin;Ko, Jae-Yong;Lee, Kyoung-Woo
    • Journal of Navigation and Port Research
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    • v.33 no.5
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    • pp.315-321
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    • 2009
  • The Very Large Marine Structure has been widely used new method of ocean space instead of method for reclamation Therefore, VLFS is proposed to coincide on such request. It can be established regardless of nature of soil and height of water, and stream of flow exists under the floating structure, there is seldom effect in natural environment. Fuertherrnore, it can do easily to do assembly and taking to pieces due to expansion or removal. Based on the regulation by class, VLFS have to possess more than enough structural strength against severe wave loading induced by green sea condition Therefore, There are performed structural simulation as well as experimental test about expected loading scenario in order to examine the safety of structure. Up to now, various examinations based on the strength limit value of the main structural material have been done based on the elasticity response analysis. However, there is little finding about the collapse behavior and the safety when the load that exceeds the collapse of the material acts. In the present study, we investigated the collapse behavior based on the ultimate limit state calculated by FE-analysis.